Differences between intestinal segments and soybean meal-induced changes in intestinal mucus composition of common carpCyprinus carpioL.

Abstract

The alimentary tract is a possible site where pathogens and toxins can enter. The alimentary tract is protected, amongst others, by mucus. In this study, tissue samples and crude mucus preparations from different parts of the intestinal tract of Cyprinus carpio (from intestinal bulb onto the hindgut) were examined using histological, histochemical and biochemical techniques. Furthermore, the response of the intestinal mucosal layer and intestinal mucus of C. carpio to acute soybean meal (SBM)‐induced enteritis was investigated. In the present study, an indication for a different protein core of mucus high molecular weight glycoproteins (HMGs) for first and second segment could not be found. However, differences in mucus glycosylation could be found. Along the gut axis, the size of the major protein peaks were not similar, which can be caused by a different glycosylation. Also, differences in staining for the antimicrobial peptide beta‐defensin 2 were found. Furthermore, changes in HMGs upon SBM diet were found similar to those found in inflammatory bowel disease (IBD) in humans. Initial changes include: changes in mucin composition, the presence of BD3 and of bacteria in internal organs. After the initial changes, all values measured returned back to the initial pre‐SBM diet values.

Effect of dietary components on the gut microbiota of aquatic animals. A never‐ending story?

“…), information on SBM meal‐induced changes in intestinal mucus composition (Van der Marel et al . ), and the effect on gut microbiota of fish. To our knowledge, the first studies evaluating the effect of SBM on the gut microbiota of fish were published in 2006 (Heikkinen et al .…”

Feeds, water quality, gut morphology and digestion in Nile tilapia (Oreochromis niloticus)

“…The first barrier that pathogens and toxins encounter is the extrinsic barrier. The extrinsic part consists of a mucus layer with antibacterial compounds such as lysozymes, complement factors and antibodies (van der Marel et al, 2014). Mucus, a viscous fluid containing mucin glycoproteins, are secreted by goblet cells.…”

“…The lumen in this region contains high nutrient concentrations, typically low numbers of bacteria, and is lined by an absorbing region (Nordrum et al, 2000). The lumen in this region contains high nutrient concentrations, typically low numbers of bacteria, and is lined by an epithelium of high paracellular permeability (van der Marel et al, 2014). In the distal part of the intestine, bacterial numbers are higher and the free nutrient concentration drops.…”

“…This would result in a higher amount of NSP in the distal intestine, which might have affected the integrity of the distal intestinal epithelium. When the intestinal epithelium is disturbed, an increased mucus flow stimulates the removal of pathogens from the entire subsequent intestine, which might prevent pathogens from entering the damaged intestinal epithelium (van der Marel et al, 2014). In Nile tilapia, the GC increased in density in the distal intestine of the intestine where mucus secretion may facilitate excretion increased amounts of undigested materials (Sklan et al, 2004b).…”

The evaluation of energy in fish feed

“…Especially alteration in amounts of NSP in the distal intestine, might affected the intestinal epithelium integrity. Disturbances of the intestinal epithelium increases the mucus flow aim to remove pathogens from the intestine and thus preventing pathogens translocation via the damaged intestinal epithelium (van der Marel et al, 2014). Facilitation of excretion of undigested material from the gut is another function of mucus (Sklan et al, 2004b).…”