Commensal microbiota-derived signals regulate host immune system through epigenetic modifications

Abstract

Commensal microbiota colonizing the digestive tract is a symbiotic partner of its host, as it plays a critical role in nutrient metabolism as well as the development and maturation of the host immune system. Although it is clear that regulation of the host-commensal relationship is crucial to mammalian health, the underlying mechanisms regulating gut homeostasis are yet to be elucidated. Epigenetic modifications, including DNA methylation and histone methylation/acetylation, alter the structure of chromatin to regulate the transcriptional program of eukaryotic cells. At the whole genome level, these modifications possibly play a key role in regulating the mutually beneficial relationship between the host and the gut microbiota. In this review, we describe how the commensal microbiota and its metabolic by-products modify the epigenome of host cells, and in turn, change their development and functional behavior.