The innate immune system is strongly implicated in uveitis. Observations that support a major role for the innate immune system include: 1) uveitis is a manifestation of several autoinflammatory syndromes including Blau syndrome; 2) activation of TLR4 by bacterial endotoxin is a standard rodent model for anterior uveitis; and 3) an adjuvant that activates the innate immune system is generally required in most animal models of T cell dependent uveitis. The intestinal microbiome is an obvious potential source for ligands that could potentially activate the innate immune system within the eye.