Effects of high ambient temperature on the community structure and composition of ileal microbiome of broilers

Abstract

The intestinal microbiome has been shown to influence animal nutrient metabolism and immune homeostasis. The present study aimed to examine the effect of heat stress on the intestinal microbiome of broilers using pyrosequencing technologies. Ninety-six Arbor Acres broiler chicks were allocated to thermoneutral control (TC; 21 ± 1°C) and high ambient temperature (HT; 31 ± 1°C) groups (6 cages of 8 birds per group), respectively, and raised in 2 controlled climate chambers from 28 to 42 d old. Genomic DNA was extracted from ileal contents isolated from 6 male broiler chicks of each group at 42 d old, and then amplified based on the V3-4 hyper-variable region of 16S rRNA. High temperature had no significant effects, but tended to influence the relative abundance of major phyla and orders in the broilers' ileal microbiota. Analysis of linear effect size feature selection identified 9 discriminative features (genus level, linear discriminant analysis score > 3). Clostridium XIVb, Streptophyta, Faecalibacterium, Rothia, Alistipes, Azospirillum, and Oscillibacter were enriched, while Coprococcus and Streptococcus were reduced in heat-stressed broilers. High temperature significantly influenced the alpha diversity, with higher observed species (P = 0.004), whole-tree phylogenetic diversity (P = 0.002), and Chao 1 (P = 0.002), but the Pielou, Shannon, and Simpson indices were unaltered (P > 0.05), indicating that high temperature increased the ileal microbiota species richness. Based on unweighted UniFrac distance metric matrices, principal component analysis showed that the HT group formed a distinct cluster clearly set apart from the TC group. Analysis of similarity also indicated that samples within groups were more similar to each other than to any samples from other groups (R = 0.626; P = 0.004). In conclusion, high temperature influenced the bacterial composition and community structure of the ileal microbiota of broilers, specifically by increasing the species richness.

High-temperature exposure alters the community structure and functional features of the intestinal microbiota in Shaoxing ducks (Anas platyrhynchos)

“…In the ileum, the abundance of Firmicutes and Proteobacteria in the heat-treated group was higher than in the control group, while the abundance of Actinobacteria in the heat-treated ducks was lower than in the controls. Wang et al. (2018) demonstrated that heat stress increased the viable counts of Firmicutes and reduced the viable counts of Proteobacteria and Bacteroidetes in the small intestinal contents of broilers, which is slightly different from the results found in this study.…”

“…The results showed that Firmicutes, Proteobacteria, and Bacteroidetes were the 3 most abundant phyla in the duodenum and jejunum of ducks, and Firmicutes, Actinobacteria, and Proteobacteria were the dominant phyla in the ileum of ducks. The major phyla of the avian intestinal microbiome are Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria ( Wei et al., 2013 , Best et al., 2017 , Xiao et al., 2017 , Wang et al., 2018 ), which is in accordance with our findings. Compared with the duodenum and jejunum of the control ducks, the abundance of Firmicutes and Bacteroidetes was increased, but the abundance of Proteobacteria was decreased after heat treatment.…”

“…In hot seasons, poultry shows decreased pathogen resistance, which often leads to the occurrence of intestinal bacterial and viral diseases ( Alhenaky et al., 2017 ), results in decreased productivity ( Lara and Rostagno, 2013 ), and causes heavy economic losses in the poultry industry ( Nawab et al., 2018 ). Previous reports have shown that the structure of chicken gut microflora is closely related to the environmental factors such as temperature ( Wang et al., 2018 , Zhu et al., 2019 ). To understand the effect of high temperature on the intestinal microbiota, we investigated the alterations of the small intestinal microbiome in ducks using high-throughput 16S rRNA gene sequencing after heat treatment.…”

Effects of acute heat stress on intestinal microbiota in grow‐finishing pigs, and associations with feed intake and serum profile

“…HS has been reported to affect the microbial structure and composition in intestines of animals within 1 week to several months (Wang et al ; He et al ; Le Sciellour et al ; Xing et al ; Zhu et al ). We observed decreased diversity and altered atructure in faecal microbiota after 24 h HS.…”

Strategies to combat the deleterious impacts of heat stress through feed restrictions and dietary supplementation (vitamins, minerals) in broilers

“…Ali et al (2018) showed that dietary supplementation with vitamin E, Cr, and Zn either individually or in combination enhanced BWG and FCR in broilers. The harmful effects of HS in broiler chicks are a result of a decrease in FI, increase in body temperature, depressed immune response, declined energy bioavailability in cells, digestibility of nutrients, metabolism, and absorption, damage in endocrine functions, disorders in the role and structure of intestinal epithelium, and variations in microbiota of the gut (Lara and Rostagno., 2013;Wang et al, 2018). Dietary supplementation with feed additives (vitamins and minerals) may improve broiler performance and combat these deleterious effects (Sahin et al, 2018;Haq et al, 2018;Zhu et al, 2017;Attia et al, 2017).…”