Figure 1.

The role of A. muciniphila in inflammatory bowel disease. Supplement with A. muciniphila reduces the levels of colonic infiltrating macrophages and cytotoxic T lymphocytes (CTLs) and relieves intestinal inflammation. The protective effects of A. muciniphila on intestinal homeostasis are associated with increased numbers of goblet cells, enhanced mucus barrier and anti-microbial responses. A. muciniphila supplement partially attenuates gut dysbiosis and resist the colonisation against other pathogens. Moreover, A. muciniphila derived SCFAs promoted the conversion from Naïve T cells to Foxp3+Treg cells through GPRs signal pathway, which may be accompanied by reduced Th1/17 cell-mediated inflammatory response. Interestingly, both pasteurised A. muciniphila and Amuc_1100, a specific outer membrane protein of the bacterium also play a similar role as A. muciniphila itself in immune protection and inhibit the infiltration macrophages and CTLs. Furthermore, A. muciniphila-derived extracellular vesicles (AmEVs), a bilayer structure composed of lipid, protein, lipopolysaccharides as well as other molecules, and Amuc_1100 also regulate intestinal barrier permeability by altering tight junction protein expression through activating TLR2 pathway.