Updated project metadata. In this study, we attempted to identify a new probiotic effector molecule of A. muciniphila that plays a role in modulating host cells through secretome analysis. We performed proteomic profiling of secretome of A. muciniphila cultivated under basal medium and BHI medium (supplemented with 0.2% mucin) using nanoflow liquid chromatography-tandem mass spectrometry (nLC-MS/MS).