Microbiota, metabolome, and immune alterations in obese mice fed a high-fat diet containing type 2 resistant starch.

SCOPE: We examined the intestinal and systemic responses to incorporating a type 2 resistant starch (RS) into a high fat diet fed to obese mice. METHODS AND
RESULTS: Diet-induced obese, C57BL/6J male mice were fed an HF diet without or with 20% (by weight) high-amylose maize resistant starch (HF-RS) for 6 weeks. Serum adiponectin levels were higher with RS consumption, but there were no differences in weight gain and adiposity. With HF-RS, the expression levels of ileal TLR2 and Reg3g and cecal occludin, TLR2, TLR4, NOD1 and NOD2 were induced; whereas colonic concentrations of the inflammatory cytokine IL-17A declined. The intestinal, serum, liver, and urinary metabolomes were also altered. HF-RS resulted in lower amino acid concentrations, including lower serum branched chain amino acids, and increased quantities of urinary di/trimethylamine, 3-indoxylsulfate, and phenylacetylglycine. Corresponding to these changes were enrichments in Bacteroidetes (S24-7 family) and certain Firmicutes taxa (Lactobacillales and Erysipelotrichaceae) with the HF-RS diet. Parabacteroides and S24-7 positively associated with cecal maltose concentrations. These taxa and Erysipelotrichaceae, Allobaculum, and Bifidobacterium were directly correlated with uremic metabolites.
CONCLUSION: Consumption of RS modified the intestinal microbiota, stimulated intestinal immunity and endocrine-responses, and modified systemic metabolomes in obese mice consuming an otherwise obesogenic diet.