Probiotic Engraftment of Akkermansia muciniphila in an In Vitro Synthetic Microbial Community.

Akkermansia muciniphila is a specialist mucin glycan-degrader that is common in the human gut. A. muciniphila is associated with host health and therefore proposed as a next-generation probiotic. However, it is unknown if consumption of live and active A. muciniphila will be effective in terms of survival and engraftment in the gut microbiome. Furthermore, it is of interest whether introduction of A. muciniphila would influence the resident mucosal microbiota. To this end, we investigate the addition of live A. muciniphila to a stable in vitro microbial mucin glycan-degrading synthetic community. A. muciniphila engrafted in this synthetic community and actively degraded mucin using essential mucin glycan-degrading enzymes. Addition of A. muciniphila did not induce major compositional changes, except that Bacteroides thetaiotaomicron increased in relative abundance at the expense of Bacteroides caccae. At the metaproteomic level, community function was not significantly affected, as peptidase, fucosidase, galactosidase and sulfatase expression remained stable. However, sialidase was significantly enriched after A. muciniphila addition, which can be explained by the relative increase of generalist glycan-degrader B. thetaiotaomicron. Overall, we show that a community without A. muciniphila still harbours a niche for this bacterium, but that A. muciniphila did not induce major changes in the in vitro mucosal synthetic community. This suggests that A. muciniphila applied as a probiotic can engraft and exert its beneficial effects on the host, without major impact on the human gut mucosal microbiota composition and function and warrants further research into A. muciniphila engraftment in vivo.