Health relevance of intestinal protein fermentation in young pigs

Abstract

The physiological role of the gastrointestinal microbiota has become an important subject of nutrition research in pigs in the past years, and the importance of intestinal microbial activity in the etiology of disease is doubtless. This review summarizes the recent knowledge related to the microbial ecology of protein fermentation and the appearance of protein-derived metabolites along the pig intestine. The amount of fermentable protein depends on factors such as dietary protein concentration, protein digestibility due to secondary or tertiary structure, the interaction with dietary compounds or anti-nutritional factors, and the secretion of endogenous proteins into the gut lumen. High protein diets increase the luminal concentrations and epithelial exposure to putatively toxic metabolites and increase the risk for post-weaning diarrhea, but the mechanisms are not yet clarified. Although the use of fermentable carbohydrates to reduce harmful protein-derived metabolites in pigs is well-established, recent studies suggest that the inclusion of fermentable carbohydrates into diets with low protein digestibility or high dietary protein level may not ameliorate all negative effects with regard to epithelial response. Based on the current knowledge, the use of diets with low levels of high-quality protein may help to reduce the risk for intestinal disease in young pigs.

Animal Models for the Study of the Relationships between Diet and Obesity: A Focus on Dietary Protein and Estrogen Deficiency

“…Indeed, the protein digestibility and protein AA composition are parameters that impact the profile of AA-derived bacterial metabolites in the large intestine. The use of fermentable carbohydrates to reduce deleterious protein-derived bacterial metabolites in pigs is well established (140), and for instance, soybean oligosaccharides have been shown to increase the presumably beneficial short-chain fatty acids while decreasing the protein-derived catabolites in the intestinal luminal content in weaned piglets (141). Last, interesting data have been recently obtained regarding the impact of the amount of dietary protein consumed by pigs on parameters like expression of AA and peptide transporters (125), or signaling pathways related to protein synthesis in muscles (142).…”

Immunomodulating effects of probiotics for microbiota modulation, gut health and disease resistance in pigs

“…Whereas the interest in immune modulation in relation to human gut health has primarily addressed severe inflammatory diseases such as inflammatory bowel disease and colon cancer, the focus of pig gut health has been both in relation to prevention of infectious diseases and performance of the animals, i.e. nutrient utilization and growth performance (Heo et al 2013;Pieper et al 2016). Weaned piglets commonly suffer from gastroenteritis caused by enterotoxigenic Escherichia coli (ETEC).…”

Co-products in maize-soybean growing-pig diets altered <i>in vitro</i> enzymatic insoluble fibre hydrolysis and fermentation in relation to botanical origin

“…Prebiotic fibre includes resistant starch, galacto and fructo oligosaccharides, mixedlinked β-glucans and soluble arabinoxylans (Aumiller et al, 2015). Beyond prebiosis, saccharolytic fermentation produces short chain fatty acids (SCFA), which beneficially modulate epithelial cell, and peripheral tissue metabolism (Byrne et al, 2015;Pieper et al, 2016). Butyrate (BUT) is the most enterotrophic and primary colonocyte energy substrate (Hamer et al, 2008;Tonel et al, 2010).…”

“…Butyrate (BUT) is the most enterotrophic and primary colonocyte energy substrate (Hamer et al, 2008;Tonel et al, 2010). In the intestinal epithelium, SCFA modulate nutrient transporter gene expression (Daly & Shirazi-Beechey, 2006) digestive enzyme secretion (Mangian & Tappenden, 2009) and mucosal immune homeostasis (Pieper et al, 2016). Peripherally, SCFA modulate satiety (Sleeth et al, 2010;Byrne et al, 2015), glucose (Theil et al, 2011) and lipid (Fushimi et al, 2006) metabolism to increase intermediary energy harvesting (Byrne et al, 2015).…”

“…Saccharolysis spares proteolytic fermentation, which tends to intensify with depletion of fermentable NSP distal to the colon (Yao et al, 2016), thereby reducing ammonia (Zervas & Zijlstra, 2002;Nahm, 2003), odours (Rideout et al, 2004) and toxic metabolites (Bach Knudsen, 2015). Biomarkers of deleterious proteolytic fermentation are the branched chain fatty acids (BCFA) iso-BUT, 2-methyl-butyrate and isovalerate (Ríos-Covián, et al, 2016;Celi et al, 2018), the metabolites of branched-chain amino acids, valine, leucine and isoleucine (Verbeke et al, 2015;Pieper et al, 2016), respectively.…”