Influence of pectin supplementation on feed fermentation characteristics in rats and pigs

Abstract

at 11 a.m. in the Aula. Lingmin TianInfluence of pectin supplementation on feed fermentation characteristics in rats and pigs 152 pages PhD thesis, Wageningen University, Wageningen, NL (2016) With references, with summary in English ISBN: 978-94-6257-728-2 AbstractThe physiological effects of dietary fiber (DFs) depend on several factors including structural features of the DFs, composition and activity of colonic microbiota, and products formed during fermentation. In this thesis, the influence of pectin supplementation to feed fermentation characteristics in rats and pigs was studied. The non-starch polysaccharides (NSP) present in the selected feed ingredient oats were characterized. Distinct populations of arabinoxylans (AXs) were observed in oats, compared to those reported for other cereals like wheat and barley. The fate of cereal AXs and soybean pectin during fermentation and the consequent effects on appetite regulation and fat accumulation were studied in rats as a model. Oat AXs were fermented less rapidly than wheat AXs in the caecum of rats. Soy pectin was fermented more early and efficiently than cereal AXs. A significant inverse correlation between rat retroperitoneal fat-pad weight and concentration and relative SCFA proportion of butyrate was observed. In a following in vivo rat experiment, commercial soy pectin together with three other soluble pectins originating from citrus and sugar beet and differing in their methyl esterification were individually supplemented to the diets. Their effects on the utilization of the different DFs present in the feed and the consequent effect on the microbial community in the colon of rats was studied. All pectins were fermented rapidly and consequently shifted fermentation of other consumed DFs (e.g. cereal AXs) to more distal part of colon, although low-methyl esterified pectin was more efficiently fermented by the microbiota than high-methyl esterified pectin. Results suggested that pectins can confer beneficial health effects through modulation of the gut microbiota. In a last in vivo experiment, citrus pectins together with a hydrothermal treated soybean meal were supplemented to pig diets to study their effect on the digestion and fermentation of carbohydrates in both the small and large intestine. Pectins, and more particularly lowmethyl esterified pectin, decreased the ileal digestibility of digestible starch resulting in more starch to be fermentated in the proximal colon of pigs. Consequently, also the fermentation patterns of DFs and the microbiota composition was affected. All pectins tested shaped the colonic microbiota from a Lactobacillus-dominated microbiota to a Prevotella-dominated community, with potential health-promoting effects.

Early-life feeding in piglets: the impact on intestinal microbiota and mucosal development

“…A possible explanation may be found in the observed chewing on the sows faeces (coprophagy) (Aviles-Rosa et al, 2019) by the CON piglets whereby they may and CON (blue dots) piglets in the pre-weaning period (Experiment 1) by acid hydrolysis to cleave the glycosidic bonds, thereby releasing mono-sugars, which were measured in gas chromatography. Following previous protocol (Tian, 2016), freeze dried faecal samples were pre-hydrolysed (72% w/w H 2 SO 4 at 30 °C for 1 h), followed by hydrolysis (1M H 2 SO 4 at 100 °C for 3 h), and derivatisation of monosaccharides to their alditol acetates with inositol as an internal standard (Englyst and Cummings, 1984). On the right panel: Pearson correlation plots between monosugars (arabinose and xylose) and the eating behaviour in the last day before sampling (video scores in seconds).…”