Response of Gut Microbiota to Dietary Fiber and Metabolic Interaction With SCFAs in Piglets

Abstract

Dietary fiber (DF) is increasingly thought to regulate diversity of piglet gut microbiota to alleviate weaning stress in piglets. This study was conducted to investigate the effects of DF on growth performance of piglets and composition of their gut microbiota, as well as the interaction between gut microbiota and short-chain fatty acids (SCFAs) in piglets. A total of 840 piglets were allocated to three dietary treatments consisting of a control group (CG), an alfalfa meal group (AG), and a commodity concentrated fiber group (OG) in a 30-day feeding trial. Gut mucosa and feces samples were used to determine bacterial community diversity by 16S rRNA gene amplicon sequencing. Fiber treatment had a positive effect on growth performance and metabolism of SCFAs in piglets, in particular, compared with CG, the diarrhea rate was significantly decreased, and the content of propionic acid (PA) in the cecum was markedly increased in AG. The Shannon indices of the jejunum microbiota in AG were higher than CG. At the genus level, compared to CG, in the duodenum, the relative abundance of Paenibacillus in AG and OG was higher; in the jejunum, the relative abundances of Bacillus, Oceanobacillus, Paenibacillus, Lactococcus, Enterococcus, and Exiguobacterium were higher, whereas the relative abundance of Mycoplasma was lower in AG; in the cecum, there was also lower relative abundance of Helicobacter in AG and OG, and furthermore, the relative abundance of Faecalibacterium in OG was higher than in CG and AG. Spearman correlation analysis showed that Pseudobutyrivibrio was positively correlated with acetic acid, PA, and butyric acid (BA), while Bacteroides and Anaerotruncus were negatively correlated with PA and BA. In addition, microbiota analyses among different intestine segments showed distinct differences in microbiota between the proximal and distal intestines. Bacteria in the proximal segments were mainly Firmicutes, while bacteria in the distal segments were mainly Bacteroidetes and Firmicutes. Overall, these findings suggested that DF treatment could reduce the diarrhea rate of piglets and had beneficial effects on gut health, which might be attributed to the alteration in gut microbiota induced by DF and the interaction of the gut microbiota with SCFAs.

Effect of Dietary Fiber Sources on In-Vitro Fermentation and Microbiota in Monogastrics

“…In the current study, it was observed that peak areas were significantly higher in the controls than treatment groups in all measured SCFA. The alfalfa treatment demonstrated a significant decrease in SCFA concentrations and peak areas in contrast to findings by Liu et al [32], who indicated that alfalfa meal treatment could produce more SCFA and improve piglet gut health, which was associated with less diarrhea. This may be dependent on the age of the pig and the level of feeding.…”

Prebiotic effects of alfalfa (Medicago sativa) fiber on cecal bacterial composition, short-chain fatty acids, and diarrhea incidence in weaning piglets

“…However, the effects of dietary ber supplementation on growth performance in pigs are inconsistent. 36 Many studies have indicated that high dietary ber supplementation increased growth, [51][52][53] while others observed no impact on growth performance. 29,30,54 The changes in the gut milieus and nutrient digestion can improve the gut microbial composition, production performance, and health of pigs.…”

“…35 The diarrhea incidence (%) was calculated using the method. 36 The acetate, butyrate, propionate, and the total SCFAs were analyzed according to the method described. 37…”

Review: Other Helicobacter species

“…34 A species rarely reported in dogs, "Helicobacter winghamensis," was isolated from fecal samples of working farm dogs. 38 Effects of host genetics and environmental conditions on fecal microbiota composition in pigs revealed that sanitary stress was of relatively minor influence on microbiota composition in high or low residual feed intake pigs although there was an increase in the abundance of Helicobacter in low residual feed intake pigs subjected to stress. 36 Weaning is a crucial period leading to serious intestinal dysbiosis and mortality in piglets.…”

“…A 30-day feeding trial of piglets with alfalfa meal or commodity concentrated fiber resulted in an improvement in gut health associated with a lower relative abundance of Helicobacter, potentially explaining the reduction of piglet diarrhea. 38 Effects of host genetics and environmental conditions on fecal microbiota composition in pigs revealed that sanitary stress was of relatively minor influence on microbiota composition in high or low residual feed intake pigs although there was an increase in the abundance of Helicobacter in low residual feed intake pigs subjected to stress. 39 Idiopathic chronic diarrhea (ICD) is a common cause of morbidity and mortality among juvenile rhesus macaques.…”