DASH INtervention to INvestigate the Gut

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.

Sex

All

Minimum age

19 Years

Maximum age

65 Years

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

• DERIVEDCarson 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. PMID 36265810