The adherence and colonization of microorganisms in fish gastrointestinal tract

Abstract Eggs, gills, skin and intestinal tracts of fish harbour bacterial communities that are thought to impact fish health through their interaction with the tissues. In particular, the gastrointestinal ( GI ) tract possesses numerous microbes and is considered an infection route. During the infections caused by pathogenic bacteria, mucosal adhesion is a critical early phase and plays an important role in fish development. This review focused on knowledge regarding the adherence and colonization of microorganisms in fish GI tract mucus, including various methods such as in vivo , in vitro , and ex vivo , host specificity, lactic acid bacteria nonfish origin using the adherence of pathogenic bacteria, gnotobiotic approaches and molecular methods. However, probiotics might not be possible to truly colonize the digestive tract of fish. The term ‘ temporal colonization ’ might be a better phrase to use when discussing probiotic persistence and presence within the mucosal layer. Recent and promising results in this field were presented based on new perspectives and future research directions of the adherence and colonization of microorganisms in fish GI tracts.