Faecalibacterium prausnitzii is known for exhibiting anti-inflammatory effects in vitro and in vivo by secreted metabolites that block nuclear factor (NF)-κB activation. The low proportion of F. prausnitzii in the microbiome of Crohn’s disease patients characterizes the microbial dysbiosis associated with that condition.

In a recent paper published in Gut, a team from the Gastroenterology & Nutrition Department from Saint-Antoine Hospital in Paris showed that F. prausnitzii produces anti-inflammatory bioactive peptides derived from a single 15 kDa protein named microbial anti-inflammatory molecule (MAM).

MAM expression in epithelial cell lines was able to block the NF-κB pathway with a dose-dependent effect. Furthermore Lactococcus lactis harbouring a MAM-cDNA encoding plasmid were able to alleviate DiNitroBenzene Sulfonic Acid-induced colitis in mice.

Identification of anti-inflammatory molecules secreted by F. prausnitzii constitutes the first step toward designing new anti-inflammatory drugs to treat Crohn’s disease. As F. prausnitzii is also known for the prediction of Crohn’s disease relapse, MAM could one day constitute an interesting biomarker for Crohn’s disease prognosis.