The Association between Gut Microbiome Diversity and Composition and Heat Tolerance in Cattle

Abstract

Cattle are raised around the world and are frequently exposed to heat stress, whether in tropical countries or in regions with temperate climates. It is universally acknowledged that compared to those in temperate areas, the cattle breeds developed in tropical and subtropical areas have better heat tolerance. However, the underlying mechanism of heat tolerance has not been fully studied, especially from the perspective of intestinal microbiomics. The present study collected fecal samples of cattle from four representative climatic regions of China, namely, the mesotemperate (HLJ), warm temperate (SD), subtropical (HK), and tropical (SS) regions. Then, the feces were analyzed using high-throughput 16S rRNA sequencing. The results showed that with increasing climatic temperature from HLJ to SS, the abundance of Firmicutes increased, accompanied by an increasing Firmicutes to Bacteroidota ratio. Proteobacteria showed a trend of reduction from HLJ to SS. Patescibacteria, Chloroflexi, and Actinobacteriota were particularly highest in SS for adapting to the tropical environment. The microbial phenotype in the tropics was characterized by an increase in Gram-positive bacteria and a decrease in Gram-negative bacteria, aerobic bacteria, and the forming of_biofilms. Consistently, the functional abundances of organismal systems and metabolism were decreased to reduce the material and energy demands in a hot environment. Genetic information processing and information storage and processing may be how gut flora deals with hot conditions. The present study revealed the differences in the structure and function of gut microbes of cattle from mesotemperate to tropical climates and provided an important reference for future research on the mechanism of heat tolerance regulated by the gut microbiota and a potential microbiota-based target to alleviate heat stress.

Microbial communities are thermally more sensitive in warm-climate lizards compared with their cold-climate counterparts

“…Second, functional genes associated with carbohydrate metabolism were enhanced in P. przewalskii , conforming to the metabolic cold adaption hypothesis which predicts an increase in the metabolic rate of ectotherms from cold environments compared with their more temperate counterparts ( Clarke, 2003 ; Schaefer and Walters, 2010 ). In a recent study on two Phrynocephalus lizards occurring in thermally different regions, Chen et al (2022) found that the gut microbiota had a higher abundance of functional categories associated with metabolism in a high-altitude species ( Phrynocephalus erythrurus ) occurring from 4,500 to 5,300 m than in a low-altitude species ( P. przewalskii ) occurring from 500 to 1,700 m. Here, we found that, as in cattle where Firmicutes assimilate nutrients more efficiently in warm tropical environments ( Zhang et al, 2022 ), the relative abundance of Firmicutes in the small-intestinal microbiota was higher in the warm-climate species than in the cold-climate species. Firmicutes are more efficient in dietary caloric intake than Bacteroidetes ( Turnbaugh et al, 2006 ; Krajmalnik-Brown et al, 2012 ; Semova et al, 2012 ), and short-chain fatty acids produced by Firmicutes can be directly absorbed by the host as an energy source to promote mass gain ( den Besten et al, 2013 ).…”

Effects of jejunum ATPase activity and antioxidant function on the growth performance, feed conversion efficiency, and intestinal flora of Hu sheep (Ovis aries)

“…The relative abundance of Euryarchaeota was lower in individuals with high ATP enzyme activity and MDA contents, and the relative abundance of Methanobrevibacter was lower in individuals with a high MDA content. Euryarchaeota represents a major branch of methane-producing archaea capable of converting acetates, methanol, and methylamines within the intestinal tract into methane [52,53], simultaneously generating ATP [54].…”

Effects of feeding Saccharomyces cerevisiae fermentation postbiotic on the fecal microbial community of Holstein dairy calves

“…Dairy calves used in the study were transported to the university site in two different batches, the first batch was received in mid-Spring and the second batch in late-Summer. In previous studies, it has been shown that environmental temperature can cause heat stress that then affects the intestinal bacterial community [ 27 , 28 ]. In addition, the difference between batches could be explained by the inherit variation that occurs between animals.…”