IL6 and major depressive disorder: For example, Yoo et al. [227] showed that fecal microbiota transplantation (FMT) from patients with IBD (Crohn’s disease and ulcerative colits) plus MDD caused depressive-like behaviors in mice, while also increasing peripheral, colonic, and hippocampal levels of corticosterone, IL-1 β, IL6, LPS, and decreasing IL-10 levels.