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

NCT05930197 · Status: COMPLETED · Phase: PHASE1 · Type: INTERVENTIONAL · Enrollment: 34

Last updated 2026-03-24

Study results available
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Summary

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.

Conditions

  • Healthy Adults

Interventions

DRUG

Bismuth subsalicylate

BSS is a commonly used, widely available, OTC medication for a variety of gastrointestinal GI symptoms. It is available in the generic form, but also under the more commonly known brands: Bismatrol; Diotame; Geri-Pectate; Kao-Tin; Peptic Relief; Pepto-Bismol; Pink Bismuth and Stomach Relief. It received approval by the US Food and Drug Administration (FDA) in 1939.

Sponsors & Collaborators

  • National Institute of Allergy and Infectious Diseases (NIAID)

    lead NIH

Principal Investigators

  • Suchitra K Hourigan, M.D. · National Institute of Allergy and Infectious Diseases (NIAID)

Study Design

Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
18 Years
Max Age
50 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2023-08-31
Primary Completion
2024-12-15
Completion
2024-12-15

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT05930197 on ClinicalTrials.gov