DASH INtervention to INvestigate the Gut (DINING)

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

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.

Study Overview

• Status: Completed
• Conditions: Cancer; Microbiota
• Intervention / Treatment: Behavioral: DASH Diet; Behavioral: standard American diet

• Study Type: Interventional
• Enrollment (Actual): 115
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 15 years to 61 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• black or white race
• non-Hispanic ethnicity
• age 19-65 years
• able to travel to the UAB Bionutrition Unit daily to retrieve meals

Exclusion Criteria:

• 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: DASH Diet; calorie-restricted DASH diet (25% fat; 57% carbohydrate; 18% protein; 34 g fiber)	Behavioral: DASH Diet; Participant will receive foods following the DASH dietary pattern for 28 days.
Active Comparator: standard American diet; calorie-restricted standard American diet (35% fat; 51% carbohydrate; %15 protein; 14 g fiber)	Behavioral: standard American diet; Participants will receive foods following the standard American diet for 28 days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean change in alpha diversity	The investigators will assess the difference in alpha diversity determined by analyzing fecal samples.	baseline - day 28
Mean change in alpha diversity	The investigators will assess the difference in alpha diversity determined by analyzing fecal samples.	day 28 - day 42
Diet specific changes in secondary bile acids	The investigators will calculate changes in cholic acid in milligrams	baseline - day 28
Diet specific changes in secondary bile acids	The investigators will calculate changes in cholic acid in milligrams	day 28 - day 42
Diet-specific changes in inflammatory marker	The investigators will calculate changes in interleukin-6 in pg/L	baseline - day 28
Diet-specific changes in inflammatory marker	The investigators will calculate changes in interleukin-6 in pg/L	day 28 - day 42

Collaborators and Investigators

• Sponsor: H. Lee Moffitt Cancer Center and Research Institute
• Collaborators: National Cancer Institute (NCI)
• Investigators: Principal Investigator: Tiffany L Carson, PhD, Moffitt Cancer Center

Publications and helpful links

General Publications

• Carson TL, Buro AW, Miller D, Pena A, Ard JD, Lampe JW, Yi N, Lefkowitz E, William VP, Morrow C, Wilson L, Barnes S, Demark-Wahnefried W. Rationale and study protocol for a randomized controlled feeding study to determine the structural- and functional-level effects of diet-specific interventions on the gut microbiota of non-Hispanic black and white adults. Contemp Clin Trials. 2022 Dec;123:106968. doi: 10.1016/j.cct.2022.106968. Epub 2022 Oct 18.

Study record dates

Study Major Dates

• Study Start (Actual): March 7, 2022
• Primary Completion (Actual): March 13, 2026
• Study Completion (Actual): March 13, 2026

Study Registration Dates

• First Submitted: August 29, 2020
• First Submitted That Met QC Criteria: August 29, 2020
• First Posted (Actual): September 4, 2020

Study Record Updates

• Last Update Posted (Actual): May 6, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms; Therapeutics; Diet, Food, and Nutrition; Physiological Phenomena; Nutritional Physiological Phenomena; Diet Therapy; Nutrition Therapy; Diet; Dietary Approaches To Stop Hypertension
• Other Study ID Numbers: MCC-21224; R01CA253219 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No