Associations of Gut Microbiota With Heat Stress-Induced Changes of Growth, Fat Deposition, Intestinal Morphology, and Antioxidant Capacity in Ducks

Abstract

Accumulating evidence has revealed the dysbiosis of gut/fecal microbiota induced by heat stress (HS) in mammals and poultry. However, the effects of HS on microbiota communities in different intestinal segments of Cherry-Valley ducks (a widely used meat-type breed) and their potential associations with growth performances, fat deposition, intestinal morphology, and antioxidant capacity have not been well evaluated yet. In this study, room temperature (RT) of 25°C was considered as control, and RT at 32°C for 8 h per day was set as the HS treatment. After 3 weeks, the intestinal contents of jejunum, ileum, and cecum were harvested to investigate the microbiota composition variations by 16S ribosomal RNA amplicon sequencing. And the weight gain, adipose indices, intestinal morphology, and a certain number of serum biochemical parameters were also measured and analyzed. The results showed the microbial species at different levels differentially enriched in duck jejunum and cecum under HS, while no significant data were observed in ileum. HS also caused the intestinal morphological changes (villus height and the ratio of villus height to crypt depth) and the reductions of growth speed (daily gain), levels of serum triglyceride (TG) and total cholesterol, and antioxidant activity (higher malondialdehyde (MDA) content and lower total antioxidant). The higher abdominal fat content and serum glucose level were also observed in HS ducks. The Spearman correlation analysis indicated that in jejunum the phyla Firmicutes and Proteobacteria were associated with average daily gain, feed/gain, serum TG and MDA levels, and villus height/crypt depth ( P < 0.05). The phylum Firmicutes and genus Acinetobacter were significantly associated with fat deposition and serum glucose level ( P < 0.05). The genus Lactobacillus was positively associated with serum total antioxidant ( P < 0.05), while some other microbial species were found negatively associated, including order Pseudomonadales , genera Acinetobacter , and unidentified_Mitochondria . However, no significant correlations were observed in cecum. These findings imply the potential roles of duck gut microbiota in the intestinal injuries, fat deposition, and reductions of growth speed and antioxidant capacity caused by HS, although the molecular mechanisms requires further investigation.

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

“…Proteobacteria (phylum) became the second enriched phylum instead of Bacteroidetes (phylum). These results are consistent with the previous report on microbiota in jejunum contents of HS ducks (He et al ). As suggested before, the prevalence of Proteobacteria (phylum) was considered to be a sign of intestinal microbial dysfunction (Shin et al ).…”

“…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.…”

“…Many studies have described the intestinal injuries after a 2‐ to 24‐h acute heat exposure (Pearce et al ; Pearce et al ; Pearce et al ; Pearce et al ). Additionally, the alterations in intestinal microbiota show close associations with intestinal damage under HS (He et al ). However, the link between the microbial alterations and intestinal injuries under acute HS is still unclear.…”

“…The changing of intestinal microbiota under HS is a dynamic process which is related to heat load and duration, and little attention has been paid to the alterations at acute phase such as within several hours. Many studies have described the intestinal injuries after a 2-to 24-h acute heat exposure (Pearce et al 2012; close associations with intestinal damage under HS (He et al 2019). However, the link between the microbial alterations and intestinal injuries under acute HS is still unclear.…”

Antioxidant Defence Systems and Oxidative Stress in Poultry Biology: An Update

“…Vaccinations [70][71][72] Microbial or virus challenges [73][74][75][76][77][78] Gut dis-bacteriosis [79][80][81][82][83] Pipping and hatching [5,84,85] A growing body of evidence clearly indicates that oxidative stress is involved in most of commercially relevant stresses in poultry production (for review see [1,2,15,60,86]).…”