Moreover, a recent study found that another probiotic enzyme Amuc_2109, a metabolic enzyme (β- N-acetyl hexosaminidase) secreted by Akk, had a significant protective effect against DSS-induced colitis mainly by improvement of the intestinal epithelial barrier function and regulation of intestinal microbiota homeostasis[89], as Amuc_2109 reshaped intestinal microbiota and inhibited the overexpression of TNF-α, IL-6, and NLRP3 in DSS-induced colitis, as well promoting the expression of tight junction protein. The gene discussed is TNF; the disease is colitis.