Effects of Tirzepatide on Gut Microbiota and Gastrointestinal Function After Drug Withdrawal in Obese Patients

October 10, 2026 updated by: ZongDan Jiang, Nanjing First Hospital, Nanjing Medical University

Effects of Tirzepatide on Gut Microbiota and the Recovery Pattern of Gastric Emptying After Drug Withdrawal in Obese Patients

This is an observational cohort study. The primary objective is to analyze the dynamic changes in gut microbiota and metabolic profiles in obese patients treated with Tirzepatide. A total of 80 participants will be enrolled: 40 normal-weight controls (NW group) and 40 obese patients receiving Tirzepatide as part of their routine clinical care (OB-T group). Fecal samples for 16S rRNA sequencing and blood samples for metabolic markers will be collected at baseline and after 3 months. Changes in gut microbiota diversity and composition will be correlated with improvements in glucose and lipid metabolism. As per the approved protocol, exploratory follow-up assessments of gastrointestinal symptoms and gastric emptying parameters will also be conducted post-treatment.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Obesity is a global public health crisis, and gut microbiota dysbiosis plays a crucial role in its pathophysiology. Tirzepatide, a dual GIP/GLP-1 receptor agonist, has shown significant weight loss effects, but its impact on the human gut microbiome remains largely unexplored. This observational study aims to fill this gap by characterizing the longitudinal changes in gut microbiota in obese patients undergoing routine Tirzepatide treatment. The investigators will use 16S rRNA V3-V4 region sequencing to analyze microbial diversity and composition (Shannon, Simpson, Chao1 indices, PCoA, LEfSe). Furthermore, The investigators will explore the associations between these microbial shifts and improvements in glucose and lipid metabolism . As secondary and exploratory objectives, gastrointestinal symptoms (GSRS) and gastric emptying function (measured by 13C-octanoic acid breath test) will be monitored during the treatment and withdrawal phases to better understand the overall physiological impact of the treatment.

Study Type

Observational

Enrollment (Estimated)

80

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • China
    • Jiangsu
      • Nanjing, Jiangsu, China
        • Nanjing First Hospital
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

A total of 80 participants will be enrolled at Nanjing First Hospital, including 40 normal-weight healthy controls and 40 obese patients receiving routine Tirzepatide treatment.

Description

Inclusion Criteria:

Normal Weight Control Group:

  • Age 18-65 years
  • 18.5 <= BMI < 24 kg/m2
  • No obesity-related complications
  • No diabetes, hypertension, or other metabolic diseases
  • No antibiotics, probiotics, or prebiotics in the past 3 months

Obese Treatment Group:

  • Age 18-65 years
  • BMI >= 30 kg/m2, or BMI >= 27 kg/m2 with at least one obesity-related complication
  • Physician-assessed indication for Tirzepatide
  • Planned initiation of Tirzepatide as part of routine clinical care
  • No antibiotics, probiotics, or prebiotics in the past 3 months

Exclusion Criteria:

  • Known inflammatory bowel disease (IBD), intestinal obstruction, or severe gastrointestinal disease
  • Gastrointestinal surgery within 6 months
  • Severe hepatic or renal impairment (ALT/AST > 3x ULN, eGFR < 30 ml/min/1.73m2)
  • History of malignancy
  • Severe psychiatric or cognitive disorder
  • Pregnancy or lactation
  • Acute infection within 1 month
  • Any condition deemed unsuitable by the investigator

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: PROSPECTIVE

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Normal Weight Control (NW)

Healthy volunteers with normal weight. No intervention is administered. Blood and fecal samples are collected.
Obese Treatment (OB-T)

Obese patients receiving Tirzepatide as part of their routine clinical care. The investigator only observes and collects blood and fecal samples.
Drug: Tirzepatide

Tirzepatide is administered as part of routine clinical care, not assigned by the investigator.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in Gut Microbiota Characteristics
Time Frame: Baseline (0 week) and 3 months

Assessed by 16S rRNA V3-V4 region sequencing. Includes Alpha diversity (Shannon, Simpson, Chao1), Beta diversity (PCoA), and core differential genera abundance (e.g., Akkermansia, Bacteroides).
Baseline (0 week) and 3 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in Fasting Plasma Glucose,, Lipid Profile, and Body Weight
Time Frame: Baseline (0 week) and 3 months

Assessed by routine fasting blood tests and anthropometric measurements. Metabolic markers include fasting plasma glucose, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and body weight.
Baseline (0 week) and 3 months
Change in Gastrointestinal Symptom Rating Scale (GSRS) Score◦
Time Frame: Baseline (0 week) and 3 months

Assessed via the Gastrointestinal Symptom Rating Scale (GSRS) questionnaire.
Baseline (0 week) and 3 months
Change in Gastric Emptying Function
Time Frame: Baseline, 3 months, and 1 week / 1 month after drug withdrawal◦

Measured by 13C-octanoic acid breath test.
Baseline, 3 months, and 1 week / 1 month after drug withdrawal◦

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Nanjing First Hospital, Nanjing Medical University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

February 1, 2027

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

July 1, 2027

Study Registration Dates

First Submitted

September 22, 2026

First Submitted That Met QC Criteria

September 22, 2026

First Posted (Actual)

September 29, 2026

Study Record Updates

Last Update Posted (Actual)

October 15, 2026

Last Update Submitted That Met QC Criteria

October 10, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • KY20260430-05-KS-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Data will not be shared due to participant privacy and ethical restrictions.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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