Importance of glycans to the host-bacteroides mutualism in the mammalian intestine.

Much of the mutualistic relationship between humans and their resident intestinal Bacteroides species is founded on glycans. The host provides plant polysaccharides and host-derived glycans and, in return, receives beneficial end products of bacterial fermentation. Glycans from the bacteria themselves are required for the establishment and survival of these organisms in the colonic ecosystem and provide immunomodulatory properties to the host. Coordinated synthesis and catabolism of bacterial glycans is likely to contribute to the host-bacterial mutualism.