Bacteroides: the good and the bad

Beneficial effects associated with Bacteroides
    Starch utilizations systems to break down complex polysaccharides
    Zwitterionic polysaccharide mediates T-cell activation
    Aids in development of GALT and a mature immune system
    Directs Paneth cells to produce antibacterial molecules, including defensins and lectins
    Deters colonization of the GI tract by pathogens
    May aid in properly development of immune tolerance and avoidance of allergy and asthma
    May have a role in preventing obesity
Bacteroides as pathogens
    Can be involved in:
        Infection after colonic contamination of the abdominal cavity and tissues
        Skin and soft tissue infections
    May produce enterotoxin and cause GI illness
    Produces hemolysins, histolytic enzymes that cause tissue destruction
    May be implicated in Crohn's disease and other IBDs
    Causes abscess formation