Effect of Bismuth Subsalicylate on the Gut Microbiome and Host Response in Healthy Adults

Completed · Phase 1

Conditions studied: Healthy Adults

In brief

Background: Many kinds of good or normal bacteria live on your skin and inside your stomach and intestines (gut). These bacteria are important to your health. What you eat, where you live, and what medicines you take can affect the bacteria in your gut. Bismuth subsalicylate (BSS) is an ingredient in common medicines for mild diarrhea and stomach pain. Products that contain BSS include Pepto-Bismol, Kao-Tin, and Pink Bismuth. But how BSS affects the bacteria in a person s gut is not fully understood. Objective: To see how BSS affects gut bacteria in healthy people. Eligibility: Healthy people aged 18 to 50 years. Design: Participants will have 6 clinic visits in up to 18 weeks. Only 1 visit must be at the NIH clinic; others may be either in-person or remote. BSS is a liquid taken by mouth. Participants will take a dose of BSS 4 times a day for 2 days. They will take the same amount of BSS as a person would take to treat diarrhea or related problems. Stool samples will be collected at each study visit. For remote visits, participants will be given a collection kit; they will collect the sample at home and send it in. Participants will take surveys at each visit. They will answer questions about their diet and health. Participants may also provide optional samples of blood, saliva, and urine. Participants may have up to 2 optional colonoscopies. A long tube will be inserted via the rectum to collect tissue samples from the intestine. Participants will be sedated or placed under anesthesia for the procedure.

Key facts

Study ID

NCT05930197

Run by

National Institute of Allergy and Infectious Diseases (NIAID)

People needed

34

Starts

2023-08-31

Expected to finish

2024-12-15

Last updated by the study team

2026-03-24

Who can join

Age: 18 and older, up to 50. Sex: any. Healthy volunteers: not accepted.

You may not qualify if…

• An individual who meets any of the following criteria will be excluded from participation in this study:
• Use of systemic antibiotics in the last 3 months.
• BSS use in the last 3 months.
• Pregnant or breastfeeding.
• Allergy to BSS.
• Allergy to other salicylates (including aspirin).
• Current use of other salicylates (including aspirin).
• Current use of anticoagulant medications.
• History of or active GI ulcers.
• History of or active bleeding disorder.
• Bloody stool within the last 3 months.
• Diarrhea within the last 2 weeks (defined as three or more loose or liquid stools per day).
• Current use of medications that may have a drug interaction with BSS.
• Not proficient in written English.
• Currently participating in another clinical trial that may affect current study procedures, per investigator s discretion.
• Any condition that, in the opinion of the study team, contraindicates participation in this study.
• Co-enrollment in other studies is restricted. Consideration for co-enrollment in clinical trials evaluating the use of a licensed medication will require the approval of the principal investigator. Study staff should be notified of co-enrollment on any other protocol as it may require the approval of the principal investigator.

Where it is running

• National Institutes of Health Clinical Center — Bethesda, Maryland, United States

Full record on ClinicalTrials.gov

Trial information comes from ClinicalTrials.gov and is refreshed daily. TrialsForMe does not provide medical care and does not run the studies it lists.