Recently, increased TNF-α and IL-6 expression in the rectum and hippocampus activated caspase-3 in the hippocampus and decreased hippocampal neurogenesis, associated to colitis and development of depressive-like behavior in mice after DSS-treatment could be reversed after a long-term treatment with Enterococcus faecalis 2001 [209]. This evidence concerns the gene IL6 and colitis.