Fiber-Mediated Nourishment of Gut Microbiota Protects against Diet-Induced Obesity by Restoring IL-22-Mediated Colonic Health

Publication date: Available online 21 December 2017
Source:Cell Host & Microbe
Author(s): Jun Zou, Benoit Chassaing, Vishal Singh, Michael Pellizzon, Matthew Ricci, Michael D. Fythe, Matam Vijay Kumar, Andrew T. Gewirtz
Dietary supplementation with fermentable fiber suppresses adiposity and the associated parameters of metabolic syndrome. Microbiota-generated fiber-derived short-chain fatty acids (SCFAs) and free fatty acid receptors including GPR43 are thought to mediate these effects. We find that while fermentable (inulin), but not insoluble (cellulose), fiber markedly protected mice against high-fat diet (HFD)-induced metabolic syndrome, the effect was not significantly impaired by either inhibiting SCFA production or genetic ablation of GPR43. Rather, HFD decimates gut microbiota, resulting in loss of enterocyte proliferation, leading to microbiota encroachment, low-grade inflammation (LGI), and metabolic syndrome. Enriching HFD with inulin restored microbiota loads, interleukin-22 (IL-22) production, enterocyte proliferation, and antimicrobial gene expression in a microbiota-dependent manner, as assessed by antibiotic and germ-free approaches. Inulin-induced IL-22 expression, which required innate lymphoid cells, prevented microbiota encroachment and protected against LGI and metabolic syndrome. Thus, fermentable fiber protects against metabolic syndrome by nourishing microbiota to restore IL-22-mediated enterocyte function.

Graphical abstract

Teaser

Dietary fiber supplements suppress adiposity and the associated parameters of metabolic syndrome. Zou et al. show that the fermentable fiber inulin impacts gut microbiota to increase intestinal epithelial proliferation, prevent colonic atrophy, reduce microbiota encroachment into the mucosa, and thereby protect against metabolic syndrome in a microbiota- and IL-22-dependent manner.


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