The Safety And Efficacy Of A Probiotic Intervention On Lactulose Hydrogen Breath Test-Positive Patients And Related Gastrointestinal Symptoms

Inclusion Criteria:

1. Aged 18-65 years old at the inclusion of the study, both female and male subjects.

2. Signed Informed Consent; willing and able to comply with study procedures.

3. Willing to maintain their diet and physical activity levels during the study.

4. Able to swallow a size-00 capsule (23mm length and 9mm width).

5. Participants with at least one of the following Rome IV diagnoses: FABD, functionaldiarrhea, IBS-M, or IBS-D.

6. Baseline weekly average of worst daily (in past 24 hours) abdominalbloating/distension score of >= 3.0 on a 0-to-10-point scale.

7. Participants with abnormal LHBT following the North American Consensusrecommendations (A rise in hydrogen of ≥20 ppm by 90 min).

Exclusion Criteria:

1. History of less than three (3) bowel movements per week.

2. With the diagnosis of IBS-C.

3. Prior gastrointestinal disease, surgery, or abdominal or pelvic radiation treatmentwhich, in the Investigator's opinion, would lead to intestinal structuring orobstruction with a risk of capsule non-excretion, including, e.g., achalasia,eosinophilic esophagitis, any IBD, or previous esophageal, gastric, smallintestinal, or colonic surgery. Appendectomy or cholecystectomy more than 3 monthsbefore the screening visit is acceptable.

4. Persons with central venous catheters.

5. History of known structural gastrointestinal abnormalities such as structures orfistulas leading to mechanical obstruction.

6. Known history abdominal radiation treatment.

7. Use of any medications in the week prior to the screening study visit, unless partof regular treatment, that could substantially alter gastrointestinal motor function (e.g., opioids, anticholinergics, or GLP-1 analogues); laxative use is allowed ifused less than 3 times a week and it is willing to keep unchanged in the week priorto the SIMBA capsule ingestions. Proton pump inhibitors (PPIs) are allowed provideda wash-out period of 48 hours is respected before swallowing the SIMBA capsules andPPI treatment is resumed only 4 hours thereafter. o Prokinetic use. Potential participants who are not using prokinetics to treat SIBOmay be eligible after a 2-week washout period, and willing to not use prokineticsfor the study duration.

8. Unable to stop using laxatives or prokinetic medications for 4 days before the studyprocedure (BT). Laxatives can be resumed after the test is conducted.

9. Organic motility disorder, including gastroparesis, intestinal pseudo-obstruction,systemic sclerosis, Ogilvie's syndrome.

10. Celiac disease (treated or untreated).

11. Any significant heart, liver, lung, kidney, blood, endocrine or nervous systemdisease, which in the opinion of the investigator, would adversely affect studysafety or outcome.

12. Cancer diagnosis or treatment within the past year (non-melanoma skin cancers areacceptable).

13. Gastrointestinal inflammatory diseases, including ulcerative colitis, Crohn'sdisease, microscopic colitis.

14. Participants with IBS presenting with alarm symptoms such as: rectal bleeding,unexplained weight loss, iron deficiency anemia, and nocturnal symptoms,

15. Participants over the age of 50 or older who have not had:

• a colon cancer screening by either a negative FIT or FOBT test within the last 2 years; OR

• a colonoscopy in the prior 10 years which was negative for colorectal cancer

16. Epilepsy diagnosis.

17. History or diagnosis of immunological diseases, infectious diseases orimmune-compromised conditions, which in the opinion of the investigator, wouldadversely affect study safety or outcome. Such as, but not limited to, hepatitis,tuberculosis, HIV positive, Parkinson's, multiple sclerosis, AIDS, lymphoma, andlong-term corticosteroid treatment.

18. History of oropharyngeal dysphagia, or other swallowing disorder with a risk ofcapsule aspiration.

19. Antibiotic use (except for topical use) ≤ 12 weeks prior to screening. Potentialparticipants may be eligible once a 12-week washout is completed.

20. Regular use of probiotics, prebiotics or synbiotics (including food and drinkscontaining added probiotics and/or probiotic yogurts with live, active cultures)within 1 month prior to screening. Potential participants may be eligible once a 1-month washout is completed.

21. Any prior Fecal Microbiota Transplantation.

22. Pregnant or breastfeeding.

23. Planning to become pregnant.

24. Alcohol or drug abuse.

25. Allergy to the components present in the probiotic and placebo capsules.

26. Are non-English speaking.

27. Are scheduled for an MRI at any time during the study. Potential participants may beeligible to participate once their MRI procedure is completed.