DASH INtervention to INvestigate the Gut

Description

The study investigators will recruit a generally healthy sample of 112 black and white adults from Birmingham, AL to participate in a 28-day randomized, controlled feeding study. Participants will be randomized to receive either the DASH diet or a standard American diet. All meals will be provided by the study. Fecal samples will be collected at multiple time points before, during, and after the dietary intervention and will be analyzed using PCR to amplify the V4 region of the 16S rRNA gene and to sequence bases using the MiSeq platform. Sequenced data will then be analyzed using QIIME. The investigators hypothesize that participants receiving the DASH diet will have a greater increase in alpha diversity and greater changes in abundances of CRC-associated microbes than participants receiving the standard American diet. The investigators will also evaluate functional-level markers including bile acid and short chain fatty acid (SCFA) production and inflammatory markers. If the investigator's hypothesis is supported, they expect to see reduced production of secondary bile acids (e.g., deoxycholic acid), greater SCFA production (e.g, butyrate), and reduction in gut and systemic inflammation (e.g, calprotectin, IL-6) among participants receiving the DASH diet compared to the standard American diet. The investigator's findings will provide preliminary evidence for the DASH diet as an approach for cultivating a healthier gut microbiota across racially diverse populations. These findings can impact clinical, translational, and population-level approaches for modification of the gut microbiota to reduce risk of chronic diseases like CRC.

Conditions

Microbiota, Cancer

Study Overview

Study Details

Study overview

The study investigators will recruit a generally healthy sample of 112 black and white adults from Birmingham, AL to participate in a 28-day randomized, controlled feeding study. Participants will be randomized to receive either the DASH diet or a standard American diet. All meals will be provided by the study. Fecal samples will be collected at multiple time points before, during, and after the dietary intervention and will be analyzed using PCR to amplify the V4 region of the 16S rRNA gene and to sequence bases using the MiSeq platform. Sequenced data will then be analyzed using QIIME. The investigators hypothesize that participants receiving the DASH diet will have a greater increase in alpha diversity and greater changes in abundances of CRC-associated microbes than participants receiving the standard American diet. The investigators will also evaluate functional-level markers including bile acid and short chain fatty acid (SCFA) production and inflammatory markers. If the investigator's hypothesis is supported, they expect to see reduced production of secondary bile acids (e.g., deoxycholic acid), greater SCFA production (e.g, butyrate), and reduction in gut and systemic inflammation (e.g, calprotectin, IL-6) among participants receiving the DASH diet compared to the standard American diet. The investigator's findings will provide preliminary evidence for the DASH diet as an approach for cultivating a healthier gut microbiota across racially diverse populations. These findings can impact clinical, translational, and population-level approaches for modification of the gut microbiota to reduce risk of chronic diseases like CRC.

Determining the structural-and Functional-level Effects of Diet-specific Interventions on the Gut-microbiota of a Diverse Sample of Southern United States Adults

DASH INtervention to INvestigate the Gut

Condition
Microbiota
Intervention / Treatment

-

Contacts and Locations

Tampa

Moffitt Cancer Center, Tampa, Florida, United States, 33612

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.

For general information about clinical research, read Learn About Studies.

Eligibility Criteria

  • * black or white race
  • * non-Hispanic ethnicity
  • * age 19-65 years
  • * able to travel to the UAB Bionutrition Unit daily to retrieve meals
  • * 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
  • * smoking/tobacco use
  • * heavy alcohol consumption
  • * major medical conditions (e.g., renal disease, diabetes, cancer

Ages Eligible for Study

19 Years to 65 Years

Sexes Eligible for Study

ALL

Accepts Healthy Volunteers

Yes

Collaborators and Investigators

H. Lee Moffitt Cancer Center and Research Institute,

Tiffany L Carson, PhD, PRINCIPAL_INVESTIGATOR, Moffitt Cancer Center

Study Record Dates

2026-06