Diet and Gut Microbiota in Health and Disease.

Gut microbiota plays an important role in host health maintenance and disease pathogenesis. The development of a stable and diverse gut microbiota is essential to various host physiologic functions such as immunoregulation, pathogen prevention, energy harvest, and metabolism. At the same time, a dysbiotic gut microbiota associated with disease is altered in structure and function, and often characterized by a decrease in species richness and proliferation of pathogenic bacterial taxa. As a shared substrate between the host and the gut microbiota, diet significantly impacts the health and disease states of the host both directly and through gut microbial metabolite production. This is demonstrated in the examples of short-chain fatty acid and trimethylamine production via bacterial metabolism of dietary complex carbohydrates and choline, respectively. In disorders related to mucosal immune dysregulation such as inflammatory bowel disease, the dysbiotic gut microbiota and diet contribute to its pathogenesis. Reversal of dysbiosis through fecal microbiota transplantation and dietary interventions may thus represent important strategies to modify the gut microbiota and its metabolite production for health maintenance as well as disease prevention and management.