The Gut Microbiome Modifies the Association between a Mediterranean Diet and Diabetes in US Hispanic / Latino Population.

CONTEXT The interrelationships among the gut microbiome, the MedDiet and a clinical endpoint of diabetes is unknown. OBJECTIVES To identify gut microbial features of a MedDiet and examine whether the association between MedDiet and diabetes varies across individuals with different gut microbial profiles. METHODS This study included 543 diabetes, 805 prediabetes and 394 normoglycemic participants from a cohort study of US Hispanic/Latino men and women. Fecal samples were profiled using 16S rRNA gene sequencing. Adherence to MedDiet was evaluated by an index based on two 24-hour dietary recalls. RESULTS A greater MedDiet adherence was associated with higher abundances of major dietary fiber metabolizers (e.g., Faecalibacterium Prausnitzii, FDR-adjusted p [q] =0.01), and lower abundances of biochemical specialists (e.g., Parabacteroides, q =0.04). The gut microbiomes of participants with greater MedDiet adherence were enriched for functions involved in dietary fiber degradation but depleted for those related to sulfur reduction and lactose and galactose degradation. The associations between MedDiet adherence and diabetes prevalence were significantly stronger among participants with depleted abundance of Prevotella (p interaction =0.03 for diabetes, 0.02 for prediabetes/diabetes, and 0.02 for prediabetes). A one-standard deviation increment in the MedDiet index was associated with 24% [odds ratio (OR) =0.76; 95% confidence interval (CI), 0.59-0.98] and 7% (OR =0.93; 95% CI, 0.72-1.20) lower odds of diabetes in Prevotella non-carriers and carriers, respectively. CONCLUSIONS Adherence to MedDiet is associated with diverse gut microorganisms and microbial functions. The inverse association between the MedDiet and diabetes prevalence varies significantly depending on gut microbial composition.