FIGURE 1: Proposed mechanism of gut bacteria mediated Candida albicans gastrointestinal colonization resistance. A) Commensal gut bacteria, particularly obligate anaerobes (i.e. Bacteriodetes thetaiotami-cron, Blautia producta), induce production of colonic host immune effectors, specifically antimicrobial peptides such as LL-37/CAMP which have Candicidal activity. B) Bacterially derived fermentation products, short-chain fatty acids (SCFAs) may have a direct effect on C. albicans growth and colonization. C) SCFAs can induce production of colonic antimicrobial peptides, including cathelicidins (LL-37/CAMP) and defensins that have activity against C. albicans.