Recruiting

Lactobacillus Rhamnosus with PPI

Sponsor:

Mayo Clinic

Code:

NCT05517928

Conditions

Healthy

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Interventions

Omeprazole

Lactobacillus rhamnosus GG

Placebo

Study Details

Brief summary:

The purpose of this study is to investigate the impact of the probiotic Lactobacillus rhamnosus (LGG) on proton pump inhibitor (PPI)-induced changes to the microbes that live in the gastrointestinal tract and are passed out in the stool. PPI medicines reduce stomach acid and are commonly used to treat acid reflux disease.

Conditions

Healthy

Study ID

NCT05517928

Start date

Mar 3, 2023

Status verified date

Jan, 2026

Completion date

Dec, 2026

Anticipated

Primary completion date

Dec, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Individuals on an unrestricted regular diet with no dietary restrictions (vegan, low FODMAP, gluten free, dairy-free etc) or other fad diets (e.g., keto, intermittent fasting, etc.).
  • Healthy subjects will be screened for current or chronic GI symptoms using a 16-item questionnaire.
  • Only those with an absence of symptoms will eligible to participate.

Exclusion Criteria:

  • For healthy volunteers, will include prior surgery altering the esophagus, stomach, and intestine (except appendectomy).
  • Chronic daily use of medications affecting GI secretion or motor function.
  • The presence of any GI-motility affecting systemic diseases or untreated psychiatric disease.
  • Pregnancy.

Study Design

Enrollment

30 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Lactobacillus rhamnosus GG Group

Subjects will receive omeprazole daily for 56 days. After 28 days, subjects will receive Lactobacillus rhamnosus GG two capsules daily taken with a meal.

placebo comparator: Placebo Group

Subjects will receive omeprazole daily for 56 days. After 28 days, subjects will receive placebo two capsules daily taken with a meal.

Interventions

Omeprazole

40 MG oral capsules daily

Lactobacillus rhamnosus GG

Given as Culturelle Digestive Probiotic in the form of oral capsules daily

Placebo

Oral capsules daily that look exactly like the study drug, but contains to active ingredient

Primary outcome measure

  • Change in Observed Operational Taxonomic Unit (OTU) diversity. [ Time Frame: Baseline, Day 56 ]

Central Contacts and Locations

Central contacts

Alexandria Ramirez

4805741853ramirez.alexandria@mayo.edu

Locations

Mayo Clinic Arizona

Recruiting

Scottsdale, Arizona, United States, 85259

Contacts

Yonas Berhe, B.S

480-301-6315berhe.yonas@mayo.edu

More Information

Sponsor

Mayo Clinic

Last update posted

Jan 8, 2026

Last verified

Jan, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Mayo Clinic on 2026-01-08.