The human gut microbiota plays a central role in intestinal health and disease. However, many of its bacterial constituents are functionally still largely unexplored. A crucial prerequisite for bacterial survival and proliferation is the creation and/or exploitation of an own niche. For many bacterial species that are linked to human disease, the inner mucus layer was found to be an important niche. Allobaculum mucolyticum, is a novel, IBD-associated species that is thought be closely associated with the host epithelium. To explore how this bacterium is able to effectively colonize this niche, we screened its genome for factors that may contribute to mucosal colonization. We identified multiple secreted Carbohydrate Active Enzymes (CAZymes). These CAZymes are able to degrade mucin O-glycans after which some of the liberated monosaccharides can be utilized for bacterial growth. The enzymatic degradation of the mucin glycans may sensitize the mucus layer for further degradation and bacterial entry. Therefore, these enzymes may play a key role in bacterial colonization of the inner mucus layer, and thus may pose an interesting target for future therapeutic intervention.