Effect of chronic and acute heat challenges on fecal microbiota composition, production, and thermoregulation traits in growing pigs1,2

Abstract

The present study aimed at investigating the impact of heat challenges on gut microbiota composition in growing pigs and its relationship with pigs’ performance and thermoregulation responses. From a total of 10 F1 sire families, 558 and 564 backcross Large White × Créole pigs were raised and phenotyped from 11 to 23 wk of age in temperate (TEMP) and in tropical (TROP) climates, respectively. In TEMP, all pigs were subjected to an acute heat challenge (3 wk at 29 °C) from 23 to 26 wk of age. Feces samples were collected at 23 wk of age both in TEMP and TROP climate (TEMP23 and TROP23 samples, respectively) and at 26 wk of age in TEMP climate (TEMP26 samples) for 16S rRNA analyses of fecal microbiota composition. The fecal microbiota composition significantly differed between the 3 environments. Using a generalized linear model on microbiota composition, 182 operational taxonomic units (OTU) and 2 pathways were differentially abundant between TEMP23 and TEMP26, and 1,296 OTU and 20 pathways between TEMP23 and TROP23. Using fecal samples collected at 23 wk of age, pigs raised under the 2 climates were discriminated with 36 OTU using a sparse partial least square discriminant analysis that had a mean classification error-rate of 1.7%. In contrast, pigs in TEMP before the acute heat challenge could be discriminated from the pigs in TEMP after the heat challenge with 32 OTU and 9.3% error rate. The microbiota can be used as biomarker of heat stress exposition. Microbiota composition revealed that pigs were separated into 2 enterotypes. The enterotypes were represented in both climates. Whatever the climate, animals belonging to the Turicibacter–Sarcina–Clostridium sensu stricto dominated enterotype were 3.3 kg heavier (P < 0.05) at 11 wk of age than those belonging to the Lactobacillus-dominated enterotype. This latter enterotype was related to a 0.3 °C lower skin temperature (P < 0.05) at 23 wk of age. Following the acute heat challenge in TEMP, this enterotype had a less-stable rectal temperature (0.34 vs. 0.25 °C variation between weeks 23 and 24, P < 0.05) without affecting growth performance (P > 0.05). Instability of the enterotypes was observed in 34% of the pigs, switching from an enterotype to another between 23 and 26 wk of age after heat stress. Despite a lower microbial diversity, the Turicibacter–Sarcina–Clostridium sensu stricto dominated enterotype was better adapted to heat stress conditions with lower thermoregulation variations.

Longitudinal Analysis of the Microbiota Composition and Enterotypes of Pigs from Post-Weaning to Finishing

“…These differences in the enterotypes at post-weaning could be related to differences in the diets. However, despite differences in the diet composition and the breeds during the finishing stage, the FE1 and FE2 enterotypes observed from 119 to 152 days of age in our study were consistent with previous observations [13,25].…”

“…Therefore, we can assume that enterotype switches could be related to transient performance modifications. However, the difference of 850 g on 25 kg pigs previously observed remained quite low [12], and in our study, the performance of pigs in FE1 and FE2 enterotypes did not differ in accordance with previous findings [25]. This suggests that the relationship between enterotypes and an animal's performance is not so clear.…”

“…Furthermore, during the finishing stage, pigs' affiliation to an enterotype was not stable and they could switch enterotypes several times from 99 to 154 days. More precisely, this instability has already been observed on 1057 pigs between 23 and 26 weeks of age where the same enterotypes as in the current experiment have been identified [25]. Interestingly, this indicates that the enterotypes identified here are robust, as the later pigs originated from various farms.…”

Gut microbiota regulate cognitive deficits and amyloid deposition in a model of Alzheimer’s disease

“…According to the methodology of Le Sciellour et al. (2019), the microbiota clustered into three enterotypes. Enterotype 1 had Lactobacillus as its best indicator; enterotype 2 was driven by Bacteroides ; and enterotype 3 was distinguished by an over‐representation of Lachnospiraceae NK4A136 group , whose abundance was inversely correlated with Lactobacillus ( r = −0.469, p = .00001; r = −0.257, p = .023).…”

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.…”