IL10 and colitis: For instance, mice lacking the anti-inflammatory cytokine IL-10, which is crucial for Treg function, develop spontaneous colitis accompanied by significant alterations in their gut microbiota, including increased abundance of pro-inflammatory Proteobacteria and decreased levels of beneficial Firmicutes.266 Similarly, Foxp3-deficient mice, which lack functional Tregs, exhibit profound dysbiosis characterized by the expansion of mucosa-associated segmented filamentous bacteria and other potentially pathogenic species.267,268