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Completed

NCT Number: NCT06342050

Socioecological Factors Associated With Ethnic Disparities in Bariatric Surgery Utilization and Post-WLS

The goal of this cross-sectional observational study is to examine potential relationships between the blood and gut microbiota of patients with obesity before and after weight loss surgery (WLS) and evaluate potential ethnic differences in the blood and gut microbiotas before and after the WLS.

The main aims / objectives of this sub-study are:

* Aim 1. Compare the relationship between the blood and the gut microbiomes among a sample of (1) pre-WLS and (2) 6-month post-WLS participants.

Hypothesis: Blood bacterial composition will resemble that of the gut microbiome among pre-WLS participants. Because the effect of WLS on the blood microbiome is not known, our post-WLS results will be mostly exploratory.

* Aim 2. Determine racial differences in the blood microbiome of the pre- and post-WLS groups.

Hypothesis2: Ethnic differences will be detected in both the pre- and post-WLS groups.

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Key information

Conditions

Obesity Body Weight Glucose Metabolism Disorders Hyperinsulinism Insulin Resistance Metabolic Diseases Metabolic Syndrome Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Observational

Primary location

UT Southwestern Medical Center

Dallas, Texas, 75390, United States

About this study

A subgroup of participants from the main study will be invited to participate in a cross-sectional sub study evaluating the relationship between blood and gut microbiotas. A total of 100 participants will be recruited, 50 participants will be recruited from the "non-completers" and the other 50 participants will be recruited from the "6 months post-WLS" follow-up group of our main project.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 18-60 years old
  • Will belong to either Non-Hispanic Whites (NHW) or Non-Hispanic Blacks (NHB) ethnic groups
  • "No-WLS" participants will have a BMI >35 kg/m2 (threshold BMI for WLS) whereas "6 months post-WLS" participants will have no BMI requirements.

Exclusion criteria

  • Having taken antibiotics in the previous 6 months;
  • Metformin, proton pump inhibitors, probiotics, or prebiotics in the previous month;
  • Currently following a vegetarian diet;
  • Pregnancy;
  • Having any infection in the previous month; and
  • Having a comorbid disease that might alter the blood microbiome composition (e.g., renal failure) or the intestinal permeability (e.g., IBS).

Treatment and study plan

Primary outcomes

  1. Gut Microbial Composition

    Time frame: Stool samples will be collected at one time point only, within a week to their in person appointment.

    Gut microbial composition will be measured by performing whole metagenome sequencing in samples previously stored in Zymo stool collection tubes.

  2. Blood Microbial Composition

    Time frame: Blood samples will be collected in fasting conditions at the Baseline visit.

    Blood microbial composition will be measured by performing 16S rRNA (ribosomal ribonucleic acid) in blood samples previously stored in Zymo blood collection tubes.

  3. Body Weight (kg)

    Time frame: Baseline

    Body weight will be measured with a calibrated SECA scale.

  4. Body Height (meters)

    Time frame: Baseline

    Body height will be measured with a stadiometer.

  5. Fat Mass (Kg)

    Time frame: Baseline

    Body fat mass will be measured by using the SECA mBCA 515.

  6. Fat-free Mass (Kg)

    Time frame: Baseline

    Fat-free mass will be measured by using the SECA mBCA 515.

  7. Body water (%)

    Time frame: Baseline

    Body water percentage will be measured by using the SECA mBCA 515.

  8. Skeletal Muscle Mass (kg)

    Time frame: Baseline

    Skeletal muscle mass will be measured by using the SECA mBCA 515.

  9. Fasting Glucose (mg/dL)

    Time frame: Baseline

    Fasting glucose will be measured after a 12h fast.

  10. Fasting Insulin (mIU/L)

    Time frame: Baseline

    Fasting insulin will be measured after a 12h fast.

  11. Lipopolysaccharides (%)

    Time frame: Baseline

    Lipopolysaccharides will be measured after a 12h fast.

  12. Lipopolysaccharides binding protein (mIU/L)

    Time frame: Baseline

    Lipopolysaccharides binding protein will be measured after a 12h fast.

Sponsors and collaborators

Lead sponsor

University of Texas Southwestern Medical Center

Other

Collaborators

  • National Institute on Minority Health and Health Disparities (NIMHD)

Registry information

Official study title

Socioecological Factors Associated With Ethnic Disparities in Bariatric Surgery Utilization and Post-Operative Weight Loss (Substudy)

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Apr 2, 2024
Registry last updated
May 22, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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