Dietary inclusion of high-amylose cornstarch increased Lactobacillus and Terrisporobacter and decreased Streptococcus in the cecal digesta of weanling pigs.

The study investigated the effect of dietary inclusion of high-amylose cornstarch (HA-starch) on cecal microbiota composition and volatile fatty acid (VFA) concentrations in weanling pigs fed high levels of cold-pressed canola-cake (CPCC). Weaned pigs (240 mixed sex; 7.1 ± 1.2 kg) were housed in 40 pens (6 pigs/pen) and fed a common commercial diet for 7 d, followed by the experimental diets for 28-d, which contained either 0% or 40% CPCC with either 0% or 40% HA-starch. At the end of the study, one pig from each pen (n = 8) was selected and euthanized to collect cecal digesta for microbial and VFA composition analyses. The HA-starch increased (P < 0.001) acetate, propionate, and butyrate concentrations, thereby increasing total VFA concentration (P < 0.001). There was a tendency for cecal butyrate and total VFA concentrations to decrease when pigs were fed the 40% CPCC diet without HA-starch but increase when fed the 40% CPCC diet containing 40% HA-starch (CPCC × HA-starch effect; P = 0.09), indicating HA-starch can increase cecal butyrate and total VFA concentrations in pigs fed a diet with high-CPCC level. The proportions of Lactobacillus and Terrisporobacter were high, whereas low proportions of Streptococcus genus were observed in the cecal microbiota of pigs fed diets containing 40% HA-starch. Also, pathways consistent with carbohydrate digestion, absorption, and phosphate metabolism were enriched in pigs when the diet included 40% HA-starch. In summary, incorporating high amounts of HA-starch in a weanling pig diet containing high levels of CPCC may benefit intestinal health and digestive performance by enhancing the abundance of probiotic commensal bacteria, contributing to increased enzymatic activity and carbohydrate metabolism.