Adhesion Mechanisms to the Host Mucosa

Adhesion of microorganisms to the intestinal mucosa is a key feature in colonization and is related to the ability of probiotics to interact with the host in order to exert beneficial health effects. Species- and strain-specific colonization strategies involve proteinaceous compounds as well as teichoic and lipoteicoic acids, peptidoglycans, and EPS. Extracellular proteins, that include cell-envelope and secreted proteins, represent the first-line interaction with the mucus layer of the GIT 

ABC-type multidrug transporters, bile efflux pumps for bile salts extrusion 

Proteins involved in fatty acid biosynthesis and EPS production 

Several factors involved in bacteria-host interactions were identified in a study aimed at achieving a detailed characterization of the secretome and membrane proteome of B. aniinalis subsp. lactis BB-12. In particular, plasminogen, collagen, fibronectin or mucin binding proteins were identified as well as proteins involved in fimbriae formation (GUad et al. 2011, 2012). 

Proteomic studies clearly highlighted that several proteins involved in adhesion mechanisms were also implicated in acid pH and hile adaptation, thus suggesting that GIT stress conditions would represent a key signal triggering the colonization process and more, in gena-al, the probiotic-host crosstalk. 

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