(OR08-01-26) A DASH Diet Increases Microbiome Diversity and Butyrate Production in Adults With Type 2 Diabetes: A Randomized Crossover Trial

Sunday, July 26, 2026

8:30 AM - 8:42 AM ET

Location: Maryland Ballroom C

Presenting Author(s)

Noel T. Mueller, PhD

Professor
University of Colorado
Wheat Ridge, Colorado, United States

Disclosure(s): Nestle Nutrition Institute: Speaker/Speaker's Bureau (Terminated)
Tiny Health LLC: Advisory Committee/Board Member (Ongoing); Stock Shareholder (excluding mutual funds) (Ongoing)

Co-Author(s)

SX

Shaoming Xiao, MHS

University of Colorado, United States
CT

Curtis Tilves

University of Colorado, United States
JD

Justine Debelius

Johns Hopkins University, United States
CM

Christine Mitchell

Johns Hopkins University, United States
SP

Scott Pilla

Johns Hopkins University, United States
JP

Jennifer Pluznick

Johns Hopkins University, United States
HY

Hsin-Chieh Yeh

Johns Hopkins University, United States
NZ

Ni Zhao

Johns Hopkins University, United States
LA

Lawrence J. Appel

Johns Hopkins Bloomberg School of Public Health, United States

Disclosure(s):

Noel T. Mueller, PhD: Nestle Nutrition Institute: Speaker/Speaker's Bureau (Terminated)
Tiny Health LLC: Advisory Committee/Board Member (Ongoing); Stock Shareholder (excluding mutual funds) (Ongoing)

Objectives: To test the hypothesis that a DASH-style diet increases gut microbiome diversity and microbial production of butyrate—a metabolite shown to improve cardiometabolic health—in adults with type 2 diabetes.

Methods: The Dietary Approaches to Stop Hypertension for Diabetes (DASH4D) trial is a randomized (n=105) 4-period crossover feeding study of adults with type 2 diabetes, a systolic blood pressure of 120-159 mmHg, and a diastolic blood pressure of < 100 mmHg. The DASH4D diet is a DASH-style diet modified for adults with diabetes. Participants were randomized to a sequence of four 5-week diets: (1) DASH4D with lower sodium, (2) DASH4D with higher sodium, (3) comparison (typical U.S.) diet with lower sodium, and (4) comparison diet with higher sodium. Our primary interest was DASH4D vs. comparison diets. Our outcomes were microbiome diversity, composition, and function measured by metagenomic sequencing of stool collected at baseline and at the end of each diet period. We rarefied microbiome data for alpha diversity analyses, used contextual tensor factorization for beta diversity, and tested for differential abundance of microbes using Analysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC).

Results: Of the 94 participants in our analysis, the mean age was 67y, 66% were female, 88% self-reported as Black, and 48% had a college degree. Participants had a mean body mass index of 32 kg/m² (61% obese), systolic blood pressure of 140 mmHg, and hemoglobin A1c of 7.0%. The DASH4D diet (vs. comparison diet) increased Shannon diversity (0.08, 95% CI: 0.01, 0.16)—driven by an increase in Pielou’s evenness (0.008, 95% CI: 0.0021, 0.0139)—and significantly altered beta diversity. The DASH4D diet (vs. comparison diet) also significantly increased an a priori butyrate-producing bacteria score, the overall microbiome content of the butyrate-production gene ‘but’, and altered the abundance of 13 species, including increasing the butyrate-producer Faecalibacterium prausnitzii.

Conclusions: Compared to a typical U.S. diet, a DASH-style diet significantly increased diversity and the abundance of butyrate-producing species and butyrate-producing gene content over a 5-week controlled feeding intervention, highlighting the importance of diet in improving the microbiome of persons with type 2 diabetes.

Funding Sources: The National Institutes of Health