PNNL

Abstract

Diet can influence the composition of the human microbiome, yet relatively few dietary ingredients have been systematically investigated with respect to their impact on the functional potential of the microbiome. Dietary resistant starch (RS) has been shown to have health benefits, but we lack a mechanistic understanding of the metabolic processes that occur in the gut during digestion of RS. Here we collected samples during a dietary crossover study with diets containing high or low amounts of RS. We determined the impact of RS on the gut microbiome and metabolic pathways in the gut, using a combination of 'omics' approaches, including sequencing, metaproteomics and metabolomics. This multi-omics approach captured changes in the abundance of specific bacterial species, proteins and metabolites after a diet high in resistant starch (HRS), providing key insights into the influence of dietary interventions on the gut microbiome. The combined data showed that a high RS diet caused an increase in the ratio of Firmicutes to Bacteroidetes, including increases in relative abundances of several members of the Firmicutes, and concurrent increases in enzymatic pathways and metabolites involved in lipid metabolism in the gut.