Modifying Diet to Improve Gut Microbiome

NCT03924778 | Not Yet Recruiting

• 1 other identifier: IRB-300003207
• Study Type: interventional
• Target: 28
• Locations: 1 country
• Sites: 1

Brief Summary

The investigators will conduct a 2-arm randomized controlled pilot, feasibility feeding study in which 28 participants will be randomized to receive either a calorie-restricted Dietary Approaches to Stop Hypertension (DASH) diet or a calorie-restricted standard American diet provided by the study for 4 weeks. Participants will be non-Hispanic black or white, generally healthy females (14 black, 14 white). The investigators will collect fecal samples at multiple time points before, during, and after the dietary intervention to analyze for changes in the gut microbiota and functional-level metabolic products. This work will be led by an interdisciplinary team including expertise in bio-behavioral science, microbiology, nutrition science, bioinformatics, and biostatistics all with cross-cutting expertise in health disparities, prevention research, nutrition, the gut microbiota, inflammation and other biomarkers. The rationale for the proposed research is that once the interactions between race, diet, and the gut microbiota are more fully understood, targeted diet modifications may provide new and innovative approaches for the prevention and treatment of obesity and obesity-related diseases.

Conditions

Obesity

Outcome Measures

Primary Outcomes (12)

• Mean Weight Change of Participants

  Weight change as measured by a scale in kilograms at multiple time points will be calculated and averaged.

  Baseline to day 28

• Mean Weight Change of Participants

  Weight change as measured by a scale in kilograms at multiple time points will be calculated and averaged.

  Day 28 to Day 42

• Mean Weight Change of Participants

  Weight change as measured by a scale in kilograms at multiple time points will be calculated and averaged.

  Baseline to day 42

• Diet-specific changes in secondary bile acid

  The investigators will calculate changes in cholic acid in milligrams.

  Baseline to day 28

• Diet-specific changes in secondary bile acid

  The investigators will calculate changes in cholic acid in milligrams.

  day 28 to day 42

• Diet-specific changes in secondary bile acid

  The investigators will calculate changes in cholic acid in milligrams.

  baseline to day 42

• Diet-specific changes in inflammatory marker

  The investigators will calculate changes in c-reactive protein in mg/L.

  baseline to day 28

• Diet-specific changes in inflammatory marker

  The investigators will calculate changes in c-reactive protein in mg/L.

  day 28 to day 42

• Diet-specific changes in inflammatory marker

  The investigators will calculate changes in c-reactive protein in mg/L.

  baseline to day 42

• Diet-specific changes in short chain fatty acids

  The investigators will calculate changes in acetic acid in mmol/L

  baseline to day 28

• Diet-specific changes in short chain fatty acids

  The investigators will calculate changes in acetic acid in mmol/L

  day 28 to day 42

• Diet-specific changes in short chain fatty acids

  The investigators will calculate changes in acetic acid in mmol/L

  baseline to day 42

Study Arms (2)

DASH diet

EXPERIMENTAL

calorie-restricted DASH diet (25% fat; 57% carbohydrate; 18% protein; 34 g fiber

Behavioral: DASH diet

standard American diet

ACTIVE COMPARATOR

calorie-restricted standard American diet (35% fat; 51% carbohydrate; %15 protein; 14 g fiber

Behavioral: standard American diet

Interventions

DASH diet BEHAVIORAL

brief description

DASH diet

standard American diet BEHAVIORAL

describe

standard American diet

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• female
• non-Hispanic, black or white
• age 19-65 years
• BMI \>= 30 kg/m\^2
• able to visit Bionutrition Unit daily

You may not qualify if:

• gastrointestinal (GI) conditions i.e., irritable bowel, diverticulitis, peptic ulcers, Crohn's, GI cancers, and adenatomous polyps
• antibiotic or probiotic use in the previous 90 days
• tobacco use
• heavy alcohol consumption
• major medical conditions (e.g., renal disease, diabetes, cancer)

Sponsors & Collaborators

• H. Lee Moffitt Cancer Center and Research Institute: lead

Study Sites (1)

Moffit Cancer Center

Tampa, Florida, 33612, United States

Location

MeSH Terms

Conditions

Obesity

Interventions

Dietary Approaches To Stop Hypertension

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Diet Therapy; Nutrition Therapy; Therapeutics; Diet; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Study Officials

• Tiffany L Carson, PhD

  Moffitt Cancer Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Tiffany L Carson, PhD

CONTACT

813-745-4944; Tiffany.Carson@moffitt.org

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 25, 2019
• First Posted: April 23, 2019
• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: September 10, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)