The gut microbiome – comprising the microbes that reside inside our digestive systems – produces many metabolites that affect human physiology. The composition and diversity of gut microbes has been associated with diseases as diverse as GI disorders, diabetes, cardiovascular disease, depression, and rheumatoid arthritis. To better understand the relationship between diet and gut microbiota, a recent study used a cross-sectional approach. By examining fecal microbiota from the Cooperative Health Research in the Region of Augsburg study, including 1,992 participants, researchers applied latent Dirichlet allocation (LDA) to identify 20 microbial subgroups within the population. They found that 8 of 20 subgroups were associated with dietary habits, while 9 of 20 were associated with the prevalence of metabolic diseases and risk factors. Certain microbial subgroups were strongly associated with eating a healthier diet including fruits, vegetables, legumes, and whole grains, and inversely correlated with type 2 diabetes. Although longitudinal studies are needed to confirm this association, the results highlight the associations between diet, metabolic disease, and microbial subgroups and identify LDA as a powerful analytic tool for improving our understanding of the human gut microbiota.