TLR5 and metabolic syndrome: Thus similar to Vijay-Kumar et al, we find that TLR5-deficiency protects mice against Salmonella infection, and that this protection does not require flagellin expression by Salmonella. TLR5−/− mice have recently been demonstrated to have an altered gut microbiota that promotes metabolic syndrome [26], and it is possible that an altered microflora or altered interactions between the host and the gut microbiota in TLR5−/− mice could establish a more effective barrier against Salmonella infection.