Efficacy of Lactobacillus Reuteri DSM 17938 for the Treatment of Acute Gastroenteritis in Children: Protocol of a Randomized Controlled Trial

Background Acute gastroenteritis (AGE) is one of the most common diseases among children. Oral rehydration therapy is the key treatment. However, despite proven efficacy, it remains underused. This is because oral rehydration solution neither reduces the frequency of bowel movements and fluid loss nor shortens the duration of illness. Hence, there is interest in adjunctive treatments. According to the 2014 guidelines developed by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition, the use of the following probiotics may be considered in the management of children with AGE in addition to rehydration therapy: Lactobacillus rhamnosus GG (low quality of evidence; strong recommendation) and Saccharomyces boulardii (low quality of evidence; strong recommendation). Less compelling evidence is available for Lactobacillus reuteri DSM 17938 (very low quality of evidence; weak recommendation). Objective Considering that evidence on L reuteri remains limited, the goal of the study is to assess the effectiveness of L reuteri DSM 17938 in the treatment of AGE in children. Children vaccinated and not vaccinated against rotavirus will be evaluated separately. Methods This will be a double-blind, placebo-controlled, randomized trial. Children between 1 and 60 months of age with AGE, defined as a change in stool consistency to loose or liquid form (according to the Bristol Stool Form scale or Amsterdam Stool Form scale) and/or an increase in the frequency of evacuations (typically ≥3 in 24 h) lasting for no longer than 5 days, will be recruited. A total of 72 children will receive either L reuteri DSM 17938 at a dose of 2×108colony-forming units twice daily or matching placebo for 5 consecutive days. A similar sample size for rotavirus vaccinated and nonvaccinated children is planned. The primary outcome measure is the duration of diarrhea. Two separate studies and reports for rotavirus vaccinated and nonvaccinated children are planned. Results The recruitment started in January 2017 and is planned to be finalized in June 2018 for rotavirus nonvaccinated children. The recruitment of rotavirus-vaccinated children may be slower due to a relatively low coverage rate in Poland. Data analysis and submission to a peer-reviewed journal is expected within 3 months after completion of the study. Conclusion This study will add to current knowledge on the efficacy of L reuteri DSM 17938 for the management of AGE. Trial registration ClinicalTrials.gov NCT02989350; https://clinicaltrials.gov/ct2/show/NCT02989350 (Archived by WebCite at http://www.webcitation.org/6slOFkyTH)

I.e does the title contain the phrase "Randomized Controlled Trial"? (if not, explain the reason under "other") yes Inne: 1a-i) Identify the mode of delivery in the title Identify the mode of delivery. Preferably use "web-based" and/or "mobile" and/or "electronic game" in the title. Avoid ambiguous terms like "online", "virtual", "interactive". Use "Internet-based" only if Intervention includes non-web-based Internet components (e.g. email), use "computer-based" or "electronic" only if o ine products are used. Use "virtual" only in the context of "virtual reality" (3-D worlds). Use "online" only in the context of "online support groups". Complement or substitute product names with broader terms for the class of products (such as "mobile" or "smart phone" instead of "iphone"), especially if the application runs on different platforms. 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 1a-i? * Copy and paste relevant sections from manuscript title (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study randomised controlled trial 1a-ii) Non-web-based components or important co-interventions in title Mention non-web-based components or important co-interventions in title, if any (e.g., "with telephone support").
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 1a-ii?
Copy and paste relevant sections from manuscript title (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 1a-iii) Primary condition or target group in the title Mention primary condition or target group in the title, if any (e.g., "for children with Type I Diabetes") Example: A Web-based and Mobile Intervention with Telephone Support for Children with Type I Diabetes: Randomized Controlled Trial 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 1a-iii? * Copy and paste relevant sections from manuscript title (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study for the treatment of acute gastroenteritis in children 1b) ABSTRACT: Structured summary of trial design, methods, results, and conclusions NPT extension: Description of experimental treatment, comparator, care providers, centers, and blinding status.

1b-i) Key features/functionalities/components of the intervention and comparator in the METHODS section of the ABSTRACT
Mention key features/functionalities/components of the intervention and comparator in the abstract. If possible, also mention theories and principles used for designing the site. Keep in mind the needs of systematic reviewers and indexers by including important synonyms. (Note: Only report in the abstract what the main paper is reporting. If this information is missing from the main body of text, consider adding it) 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 1b-i? * Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This will be a doubleblind, placebocontrolled, randomised trial. A total of 72 children will receive either L reuteri DSM 17938 108 colony forming units (CFU) twice daily or matching placebo for 5 consecutive days.
1b-ii) Level of human involvement in the METHODS section of the ABSTRACT Clarify the level of human involvement in the abstract, e.g., use phrases like "fully automated" vs. "therapist/nurse/care provider/physician-assisted" (mention number and expertise of providers involved, if any). (Note: Only report in the abstract what the main paper is reporting. If this information is missing from the main body of text, consider adding it) 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 1b-ii?
Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 1b-iii) Open vs. closed, web-based (self-assessment) vs. face-to-face assessments in the METHODS section of the ABSTRACT Mention how participants were recruited (online vs. o ine), e.g., from an open access website or from a clinic or a closed online user group (closed usergroup trial), and clarify if this was a purely web-based trial, or there were face-to-face components (as part of the intervention or for assessment). Clearly say if outcomes were self-assessed through questionnaires (as common in web-based trials). Note: In traditional o ine trials, an open trial (open-label trial) is a type of clinical trial in which both the researchers and participants know which treatment is being administered. To avoid confusion, use "blinded" or "unblinded" to indicated the level of blinding instead of "open", as "open" in web-based trials usually refers to "open access" (i.e. participants can self-enrol). (Note: Only report in the abstract what the main paper is reporting. If this information is missing from the main body of text, consider adding it) 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 1b-iii?
Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The recruitment started in January 2017 and is planned to be finalized up to June 2018 for rotavirus nonvaccinated children. The recruitment of rotavirusvaccinated children may be slower due to a relatively low coverage rate in Poland 1b-iv) RESULTS section in abstract must contain use data Report number of participants enrolled/assessed in each group, the use/uptake of the intervention (e.g., attrition/adherence metrics, use over time, number of logins etc.), in addition to primary/secondary outcomes. (Note: Only report in the abstract what the main paper is reporting. If this information is missing from the main body of text, consider adding it) 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 1b-iv?
Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study A total of 72 children will receive either L reuteri DSM 17938 108 colony forming units (CFU) twice daily or matching placebo for 5 consecutive days. A similar sample size for rotavirus vaccinated and nonvaccinated children is planned.
1b-v) CONCLUSIONS/DISCUSSION in abstract for negative trials Conclusions/Discussions in abstract for negative trials: Discuss the primary outcome -if the trial is negative (primary outcome not changed), and the intervention was not used, discuss whether negative results are attributable to lack of uptake and discuss reasons. (Note: Only report in the abstract what the main paper is reporting. If this information is missing from the main body of text, consider adding it) 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 1b-v?
Copy and paste relevant sections from the manuscript abstract (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study subitem not at all important essential Does your paper address subitem 2a-ii? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The intervention under investigation is L reuteri DSM 17938. The placebo drops consists of a mixture of pharmaceutical grade medium chain triglycerides and sunflower oil together with pharmaceutical grade silicon dioxide to give the product the correct rheological properties. The formulation is identical with the active product but without L reuteri DSM 17938. In our trial, we choose to use a placebo for a comparator, as it is widely regarded as the gold standard for testing the efficacy of new treatments 2b) In INTRODUCTION: Speci c objectives or hypotheses Does your paper address CONSORT subitem 2b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study To assess the effectiveness of L reuteri DSM 17938 in the treatment of AGE in children. Children vaccinated and not vaccinated against rotavirus will be evaluated separately. not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This study is designed as a randomised, doubleblinded, placebo controlled trial, with allocation 1:1, and it is described in more detail in the subsequent sections.

METHODS
3b) Important changes to methods after trial commencement (such as eligibility criteria), with reasons Does your paper address CONSORT subitem 3b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The trial was registered at ClinicalTrials.gov. NCT02989350 and any important changes in the protocol will be implemented there.

3b-i) Bug xes, Downtimes, Content Changes
Bug xes, Downtimes, Content Changes: ehealth systems are often dynamic systems. A description of changes to methods therefore also includes important changes made on the intervention or comparator during the trial (e.g., major bug xes or changes in the functionality or content) (5-iii) and other "unexpected events" that may have in㾍uenced study design such as staff changes, system failures/downtimes, etc. [2].
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 3b-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 4a) Eligibility criteria for participants Does your paper address CONSORT subitem 4a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study zinc (including zinccontaining oral rehydration solution) within a week prior to enrolment (a single dose is allowed). 3. Breastfeeding (>50%). 4.
4a-i) Computer / Internet literacy Computer / Internet literacy is often an implicit "de facto" eligibility criterion -this should be explicitly clari ed. 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 4a-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 4a-ii) Open vs. closed, web-based vs. face-to-face assessments: Open vs. closed, web-based vs. face-to-face assessments: Mention how participants were recruited (online vs. o ine), e.g., from an open access website or from a clinic, and clarify if this was a purely web-based trial, or there were face-to-face components (as part of the intervention or for assessment), i.e., to what degree got the study team to know the participant. In online-only trials, clarify if participants were quasianonymous and whether having multiple identities was possible or whether technical or logistical measures (e.g., cookies, email con rmation, phone calls) were used to detect/prevent these.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 4a-ii? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The recruitment will take place in the Emergency Room and the Department of Paediatrics of the St Hedwig of Silesia Hospital in Trzebnica, Poland. However, inclusion of outpatients and involvement of other recruiting sites are under consideration provided that the study staff is experienced, adequately trained, and competent in conducting clinical trials.
4a-iii) Information giving during recruitment Information given during recruitment. Specify how participants were briefed for recruitment and in the informed consent procedures (e.g., publish the informed consent documentation as appendix, see also item X26), as this information may have an effect on user self-selection, user expectation and may also bias results.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 4a-iii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Participants will be randomised after their first visit to the emergency room or after admission to the hospital. Caregivers will receive oral and written information on the study. Written informed consent will by obtained by physicians involved in the study.
4b) Settings and locations where the data were collected Does your paper address CONSORT subitem 4b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Participants will be randomised after their first visit to the emergency room or after admission to the hospital.

4b-i) Report if outcomes were (self-)assessed through online questionnaires
Clearly report if outcomes were (self-)assessed through online questionnaires (as common in web-based trials) or otherwise.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 4b-i? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 4b-ii) Report how institutional a liations are displayed Report how institutional a liations are displayed to potential participants [on ehealth media], as a liations with prestigious hospitals or universities may affect volunteer rates, use, and reactions with regards to an intervention.(Not a required item -describe only if this may bias results) 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 4b-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The recruitment will take place in the Emergency Room and the Department of Paediatrics of the St Hedwig of Silesia Hospital in Trzebnica, Poland. However, inclusion of outpatients and involvement of other recruiting sites are under consideration 5) The interventions for each group with su cient details to allow replication, including how and when they were actually administered

5-i) Mention names, credential, a liations of the developers, sponsors, and owners
Mention names, credential, a liations of the developers, sponsors, and owners [6] (if authors/evaluators are owners or developer of the software, this needs to be declared in a "Con㾍ict of interest" section or mentioned elsewhere in the manuscript).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study placebo drops consists of a mixture of pharmaceutical grade medium chain triglycerides and sunflower oil together with pharmaceutical grade silicon dioxide to give the product the correct rheological properties. The dose of L reuteri DSM 17938 will be 2 x 108 CFU. Both L reuteri DSM 17938 and placebo will be taken orally, twice daily 5 drops, for consecutive 5 days. Caregivers will be instructed to administer the study products at the same time in a day. If needed, discontinuation or modification of the treatment may be considered at the discretion of the physician.

5-ii) Describe the history/development process
Describe the history/development process of the application and previous formative evaluations (e.g., focus groups, usability testing), as these will have an impact on adoption/use rates and help with interpreting results. Does your paper address subitem 5-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study

5-iii) Revisions and updating
Revisions and updating. Clearly mention the date and/or version number of the application/intervention (and comparator, if applicable) evaluated, or describe whether the intervention underwent major changes during the evaluation process, or whether the development and/or content was "frozen" during the trial.
Describe dynamic components such as news feeds or changing content which may have an impact on the replicability of the intervention (for unexpected events see item 3b).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-iii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study

5-iv) Quality assurance methods
Provide information on quality assurance methods to ensure accuracy and quality of information provided [1], if applicable.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-iv?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The caregivers will be asked to bring the remaining study product and diary to the study site at the end of the intervention period. Compliance with the study protocol will be checked by measuring the volume left unused. Based on previously published trials, it seems to be appropriate to consider those participants receiving >75% of the recommended doses as noncompliant.
5-v) Ensure replicability by publishing the source code, and/or providing screenshots/screencapture video, and/or providing 㾍owcharts of the algorithms used Ensure replicability by publishing the source code, and/or providing screenshots/screen-capture video, and/or providing 㾍owcharts of the algorithms used. Replicability (i.e., other researchers should in principle be able to replicate the study) is a hallmark of scienti c reporting.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-v?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study

5-vi) Digital preservation
Digital preservation: Provide the URL of the application, but as the intervention is likely to change or disappear over the course of the years; also make sure the intervention is archived (Internet Archive, webcitation.org, and/or publishing the source code or screenshots/videos alongside the article). As pages behind login screens cannot be archived, consider creating demo pages which are accessible without login.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-vi?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study

5-vii) Access
Access: Describe how participants accessed the application, in what setting/context, if they had to pay (or were paid) or not, whether they had to be a member of speci c group. If known, describe how participants obtained "access to the platform and Internet" [1]. To ensure access for editors/reviewers/readers, consider to provide a "backdoor" login account or demo mode for reviewers/readers to explore the application (also important for archiving purposes, see vi). Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study subitem not at all important essential Does your paper address subitem 5-viii? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study

5-ix) Describe use parameters
Describe use parameters (e.g., intended "doses" and optimal timing for use). Clarify what instructions or recommendations were given to the user, e.g., regarding timing, frequency, heaviness of use, if any, or was the intervention used ad libitum.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-ix?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study

5-x) Clarify the level of human involvement
Clarify the level of human involvement (care providers or health professionals, also technical assistance) in the e-intervention or as co-intervention (detail number and expertise of professionals involved, if any, as well as "type of assistance offered, the timing and frequency of the support, how it is initiated, and the medium by which the assistance is delivered". It may be necessary to distinguish between the level of human involvement required for the trial, and the level of human involvement required for a routine application outside of a RCT setting (discuss under item 21 -generalizability).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-x?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 5-xi) Report any prompts/reminders used Report any prompts/reminders used: Clarify if there were prompts (letters, emails, phone calls, SMS) to use the application, what triggered them, frequency etc. It may be necessary to distinguish between the level of prompts/reminders required for the trial, and the level of prompts/reminders for a routine application outside of a RCT setting (discuss under item 21 -generalizability).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-xi? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 5-xii) Describe any co-interventions (incl. training/support) Describe any co-interventions (incl. training/support): Clearly state any interventions that are provided in addition to the targeted eHealth intervention, as ehealth intervention may not be designed as stand-alone intervention. This includes training sessions and support [1]. It may be necessary to distinguish between the level of training required for the trial, and the level of training for a routine application outside of a RCT setting (discuss under item 21 -generalizability.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 5-xii? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 6a) Completely de ned pre-speci ed primary and secondary outcome measures, including how and when they were assessed Does your paper address CONSORT subitem 6a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study ▸ Need for hospitalisation of outpatients 6a-ii) Describe whether and how "use" (including intensity of use/dosage) was de ned/measured/monitored Describe whether and how "use" (including intensity of use/dosage) was de ned/measured/monitored (logins, log le analysis, etc.). Use/adoption metrics are important process outcomes that should be reported in any ehealth trial.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 6a-ii?
Copy and paste relevant sections from manuscript text 6a-iii) Describe whether, how, and when qualitative feedback from participants was obtained Describe whether, how, and when qualitative feedback from participants was obtained (e.g., through emails, feedback forms, interviews, focus groups).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 6a-iii?
Copy and paste relevant sections from manuscript text 6b) Any changes to trial outcomes after the trial commenced, with reasons Does your paper address CONSORT subitem 6b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The trial was registered at ClinicalTrials.gov. NCT02989350 and any important changes in the protocol will be implemented there.
7a) How sample size was determined NPT: When applicable, details of whether and how the clustering by care provides or centers was addressed 7a-i) Describe whether and how expected attrition was taken into account when calculating the sample size Describe whether and how expected attrition was taken into account when calculating the sample size.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 7a-i?
Copy and paste relevant sections from manuscript title (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study will shorten the duration of symptoms by 24 hours (±24 h

7b) When applicable, explanation of any interim analyses and stopping guidelines
Does your paper address CONSORT subitem 7b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The study will be carried out in accordance with the approved protocol. L reuteri DSM 17938 is being safely used worldwide for a number of indications, and the Food and Drug Administration applied to it the Generally Recognized as Safe (GRAS) status [ ]. Still, an independent Data and Safety Monitoring Board (DSMB) will be set up prior to the start of the study. The DSMB will review data after recruitment of 25%, 50%, and 75% subjects to review the study progress and all adverse events.
8a) Method used to generate the random allocation sequence NPT: When applicable, how care providers were allocated to each trial group Does your paper address CONSORT subitem 8a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study A computergenerated randomisation list will be prepared by a person with no clinical involvement in the trial using a computer program (StatsDirect) with an allocation ratio of 1:1 and with a block of six. The randomisation lists will be stratified according to rotavirus vaccination status (non vaccinated and vaccinated; the latter will be defined as receiving at least one dose of rotavirus vaccine).
8b) Type of randomisation; details of any restriction (such as blocking and block size) Does your paper address CONSORT subitem 8b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study A computergenerated randomisation list will be prepared by a person with no clinical involvement in the trial using a computer program (StatsDirect) with an allocation ratio of 1:1 and with a block of six. The randomisation lists will be stratified according to rotavirus vaccination status (non vaccinated and vaccinated; the latter will be defined as receiving at least one dose of rotavirus vaccine). 9) Mechanism used to implement the random allocation sequence (such as sequentially numbered containers), describing any steps taken to conceal the sequence until interventions were assigned Does your paper address CONSORT subitem 9? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The allocation sequence will be concealed from the researchers enrolling and assessing participants in sequentially numbered, white, opaque, sealed and stapled envelopes which will be opened only after getting informed consent and registering the basic demographic data to case report form (CRF). Consecutive randomisation numbers will be given to participants at enrolment. The study product will be packaged as product A or product B, and will be given according to the randomisation list.
10) Who generated the random allocation sequence, who enrolled participants, and who assigned participants to interventions Does your paper address CONSORT subitem 10? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study the study products (active and placebo) were prepared and then labelled by persons not involved in the study.
that the study staff is experienced, adequately trained, and competent in conducting clinical trials.
11a) If done, who was blinded after assignment to interventions (for example, participants, care providers, those assessing outcomes) and how NPT: Whether or not administering co-interventions were blinded to group assignment 11a-i) Specify who was blinded, and who wasn't Specify who was blinded, and who wasn't. Usually, in web-based trials it is not possible to blind the participants [1, 3] (this should be clearly acknowledged), but it may be possible to blind outcome assessors, those doing data analysis or those administering co-interventions (if any).

2 3 4 5
subitem not at all important essential Does your paper address subitem 11a-i? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Researchers, caregivers, outcome assessors, and a person responsible for the statistical analysis will be blinded to the intervention until the completion of the study.
11a-ii) Discuss e.g., whether participants knew which intervention was the "intervention of interest" and which one was the "comparator" Informed consent procedures (4a-ii) can create biases and certain expectations -discuss e.g., whether participants knew which intervention was the "intervention of interest" and which one was the "comparator".
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 11a-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Researchers, caregivers, outcome assessors, and a person responsible for the statistical analysis will be blinded to the intervention until the completion of the study. The information on intervention assignments will be stored in a sealed envelope in a safe place in the administrative part of the department. The personal information about potential and enrolled participants will be stored in a locker within the study site, accessible for the involved researchers only.
11b) If relevant, description of the similarity of interventions (this item is usually not relevant for ehealth trials as it refers to similarity of a placebo or sham intervention to a active medication/intervention) Does your paper address CONSORT subitem 11b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The study products (active and placebo) will be packaged in identical bottles. Contents will look and taste the same.
12a) Statistical methods used to compare groups for primary and secondary outcomes NPT: When applicable, details of whether and how the clustering by care providers or centers was addressed Does your paper address CONSORT subitem 12a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study to compare percentages. For continuous outcomes, differences in means or differences in medians (depending on the distribution of the data), and for dichotomous outcomes, the RR and number needed to treat (NNT), all with a 95% CI, will be calculated. The difference between study groups will be considered significant when the p value is <0.05, when the 95% CI for RR does not include 1.0, or when the 95% CI for MD does not include 0. All statistical tests will be two tailed and performed at the 5% level of significance. Two independent reports (rotavirusvaccinated and nonvaccinated children) are planned.
12a-i) Imputation techniques to deal with attrition / missing values Imputation techniques to deal with attrition / missing values: Not all participants will use the intervention/comparator as intended and attrition is typically high in ehealth trials. Specify how participants who did not use the application or dropped out from the trial were treated in the statistical analysis (a complete case analysis is strongly discouraged, and simple imputation techniques such as LOCF may also be problematic [4]).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 12a-i? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study All analysis will be conducted on an intentiontotreat basis, including all patients in the groups to which they are randomised for whom outcomes are available (including dropouts and withdrawals).

12b) Methods for additional analyses, such as subgroup analyses and adjusted analyses
Does your paper address CONSORT subitem 12b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Two independent reports (rotavirusvaccinated and nonvaccinated children) are planned. subitem not at all important essential Does your paper address subitem X26-i?

X26) REB/IRB Approval and Ethical Considerations
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study approval for the study before recruitment commenced. Verbal and written information regarding informed consent will be presented to the caregivers. Any modifications to the protocol that may affect the conduct of the study will be presented to the Bioethical Committee. The full protocol will be available freely due to openaccess publication. The findings of this randomised controlled trial will be submitted to a peer reviewed journal. Abstracts will be submitted to relevant national and international conferences. The need for separate reporting of data on rotavirusvaccinated and nonvaccinated populations is foreseen. subitem not at all important essential Does your paper address subitem X26-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study

X26-iii) Safety and security procedures
Safety and security procedures, incl. privacy considerations, and any steps taken to reduce the likelihood or detection of harm (e.g., education and training, availability of a hotline) 1 2 3 4 5 subitem not at all important essential Does your paper address subitem X26-iii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Although the occurrence of adverse events as a result of participation in the current trial is not expected, data on adverse events data will be collected. All serious adverse events will be immediately reported to the study coordinators who will be responsible for notifying the Ethics Committee, all participating investigators, and the manufacturer of the study products.

RESULTS
13a) For each group, the numbers of participants who were randomly assigned, received intended treatment, and were analysed for the primary outcome NPT: The number of care providers or centers performing the intervention in each group and the number of patients treated by each care provider in each center Does your paper address CONSORT subitem 13a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is study protocol 13b) For each group, losses and exclusions after randomisation, together with reasons Does your paper address CONSORT subitem 13b? (NOTE: Preferably, this is shown in a CONSORT 㾍ow diagram) * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is study protocol

13b-i) Attrition diagram
Strongly recommended: An attrition diagram (e.g., proportion of participants still logging in or using the intervention/comparator in each group plotted over time, similar to a survival curve) or other gures or tables demonstrating usage/dose/engagement.

2 3 4 5
subitem not at all important essential Does your paper address subitem 13b-i?
Copy and paste relevant sections from the manuscript or cite the gure number if applicable (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is study protocol 14a) Dates de ning the periods of recruitment and followup Does your paper address CONSORT subitem 14a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study All study participants will be followed up for the duration of the intervention (5 days), and then for additional 3 days or until the cessation of diarrhoea.
14a-i) Indicate if critical "secular events" fell into the study period Indicate if critical "secular events" fell into the study period, e.g., signi cant changes in Internet resources available or "changes in computer hardware or Internet delivery resources" 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 14a-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 14b) Why the trial ended or was stopped (early) Does your paper address CONSORT subitem 14b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study subitem not at all important essential Does your paper address subitem 15-i? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is study protocol 16) For each group, number of participants (denominator) included in each analysis and whether the analysis was by original assigned groups 16-i) Report multiple "denominators" and provide de nitions Report multiple "denominators" and provide de nitions: Report N's (and effect sizes) "across a range of study participation [and use] thresholds" [1], e.g., N exposed, N consented, N used more than x times, N used more than y weeks, N participants "used" the intervention/comparator at speci c pre-de ned time points of interest (in absolute and relative numbers per group). Always clearly de ne "use" of the intervention. This is study protocol 16-ii) Primary analysis should be intent-to-treat Primary analysis should be intent-to-treat, secondary analyses could include comparing only "users", with the appropriate caveats that this is no longer a randomized sample (see 18-i).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 16-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is study protocol 17a) For each primary and secondary outcome, results for each group, and the estimated effect size and its precision (such as 95% con dence interval) Does your paper address CONSORT subitem 17a? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study used. The χ2 test or Fisher's exact test will be used, when appropriate, to compare percentages. For continuous outcomes, differences in means or differences in medians (depending on the distribution of the data), and for dichotomous outcomes, the RR and number needed to treat (NNT), all with a 95% CI, will be calculated. The difference between study groups will be considered significant when the p value is <0.05, when the 95% CI for RR does not include 1.0, or when the 95% CI for MD does not include 0. All statistical tests will be two tailed and performed at the 5% level of significance.

17a-i) Presentation of process outcomes such as metrics of use and intensity of use
In addition to primary/secondary (clinical) outcomes, the presentation of process outcomes such as metrics of use and intensity of use (dose, exposure) and their operational de nitions is critical. This does not only refer to metrics of attrition (13-b) (often a binary variable), but also to more continuous exposure metrics such as "average session length". These must be accompanied by a technical description how a metric like a "session" is de ned (e.g., timeout after idle time) [1] (report under item 6a).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 17a-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study 17b) For binary outcomes, presentation of both absolute and relative effect sizes is recommended Does your paper address CONSORT subitem 17b? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is study protocol 18) Results of any other analyses performed, including subgroup analyses and adjusted analyses, distinguishing pre-speci ed from exploratory Does your paper address CONSORT subitem 18? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is study protocol

18-i) Subgroup analysis of comparing only users
A subgroup analysis of comparing only users is not uncommon in ehealth trials, but if done, it must be stressed that this is a self-selected sample and no longer an unbiased sample from a randomized trial (see 16-iii).
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 18-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Two independent reports (rotavirusvaccinated and nonvaccinated children) are planned.

19) All important harms or unintended effects in each group
(for speci c guidance see CONSORT for harms) Does your paper address CONSORT subitem 19? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Although the occurrence of adverse events as a result of participation in the current trial is not expected, data on adverse events data will be collected. All serious adverse events will be immediately reported to the study coordinators who will be responsible for notifying the Ethics Committee, all participating investigators, and the manufacturer of the study products.

19-i) Include privacy breaches, technical problems
Include privacy breaches, technical problems. This does not only include physical "harm" to participants, but also incidents such as perceived or real privacy breaches [1], technical problems, and other unexpected/unintended incidents. "Unintended effects" also includes unintended positive effects [2]. NPT: In addition, take into account the choice of the comparator, lack of or partial blinding, and unequal expertise of care providers or centers in each group 22-i) Restate study questions and summarize the answers suggested by the data, starting with primary outcomes and process outcomes (use) Restate study questions and summarize the answers suggested by the data, starting with primary outcomes and process outcomes (use). Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is study protocol 20) Trial limitations, addressing sources of potential bias, imprecision, and, if relevant, multiplicity of analyses

20-i) Typical limitations in ehealth trials
Typical limitations in ehealth trials: Participants in ehealth trials are rarely blinded. Ehealth trials often look at a multiplicity of outcomes, increasing risk for a Type I error. Discuss biases due to non-use of the intervention/usability issues, biases through informed consent procedures, unexpected events.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 20-i? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study contribute to the formulation of further recommendations on the use of Lactobacillus reuteri DSM 17938 for the treatment of acute gastroenteritis in children.
• Stool volume, one of the objective ways of assessing the efficacy of antidiarrhoeal drugs, will not be assessed.

•
The recruitment of rotavirusvaccinated children may be slow due to a relatively low coverage rate in Poland, likely due to the high vaccine cost. 21) Generalisability (external validity, applicability) of the trial ndings NPT: External validity of the trial ndings according to the intervention, comparators, patients, and care providers or centers involved in the trial 21-i) Generalizability to other populations Generalizability to other populations: In particular, discuss generalizability to a general Internet population, outside of a RCT setting, and general patient population, including applicability of the study results for other organizations 1 2 3 4 5 subitem not at all important essential Does your paper address subitem 21-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information https://docs.google.com/forms/d/e/1FAIpQLSfZBSUp1bwOc_OimqcS64RdfIAFvmrTSkZQL23O8O9hrL5Sw/viewform?hl=en_US&formkey=dGlKd2Z2… 32/35 not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Taken together, more studies are needed to establish the efficacy of L reuteri DSM 17938 in the management of AGE in children. We aim to conduct a welldesigned study, with sufficient power, an adequate follow up period, and relevant clinical end points. The study will be led by a team experienced in performing clinical trials in children with AGE [ ], and following the same protocol as in one of our recent trials on AGE [ ].
21-ii) Discuss if there were elements in the RCT that would be different in a routine application setting Discuss if there were elements in the RCT that would be different in a routine application setting (e.g., prompts/reminders, more human involvement, training sessions or other co-interventions) and what impact the omission of these elements could have on use, adoption, or outcomes if the intervention is applied outside of a RCT setting.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem 21-ii?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study OTHER INFORMATION 23) Registration number and name of trial registry Does your paper address CONSORT subitem 23? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study The study protocol is under registration at ClinicalTrials.gov. NCT02989350.

24)
Where the full trial protocol can be accessed, if available Does your paper address CONSORT subitem 24? * Cite a Multimedia Appendix, other reference, or copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study This is full trial protocol 25) Sources of funding and other support (such as supply of drugs), role of funders Does your paper address CONSORT subitem 25? * Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study There is no external funding for this study.

X27) Con㾍icts of Interest (not a CONSORT item)
X27-i) State the relation of the study team towards the system being evaluated In addition to the usual declaration of interests ( nancial or otherwise), also state the relation of the study team towards the system being evaluated, i.e., state if the authors/evaluators are distinct from or identical with the developers/sponsors of the intervention.
1 2 3 4 5 subitem not at all important essential Does your paper address subitem X27-i?
Copy and paste relevant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from your manuscript), or elaborate on this item by providing additional information not in the ms, or brie㾍y explain why the item is not applicable/relevant for your study Competing interests statement: H Szymański declares no conflicts of interest; H Szajewska has served as a speaker for BioGaia, the manufacturer of L reuteri DSM 17938.

About the CONSORT EHEALTH checklist
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hour
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