Harnessing gut commensals to combat disease

Abstract

The mammalian alimentary tract harbors hundreds of species of commensal microbes that critically influence a multitude of host physiological functions. Unfavorable alterations of the gut microbiota composition often correlate with several negative health outcomes. Thus, the amelioration of microbiota dysfunction is a promising route for future therapeutics for several diseases. We have been aiming to understand the features and functions, particularly immunological attributes, of the microbiota, and trying to identify responsible bacterial species and factors for shaping the immune system. We have succeeded in isolation of human and mouse gut-associated commensal bacterial strains that specifically affect the development and function of Th17 cells, Treg cells, Th1 cells or CD8 T cells. In addition, we have identified trypsin-degrading bacterial species. Our findings would allow for designing bacterial consortia that activate or suppress specific adaptive immune programs, potentially resulting in development of better therapeutics for numerous diseases involving the immune system, including infectious disease, autoimmunity, allergy, and cancer.