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Seasonal Variation Influences on Intestinal Microbiota in Rats. Liu Jie,Song Yi,Lu Xiaoguang,Chen Tuo,Guo Wenxiu,Fan Zhiwei,Kang Xin,Wang Yu,Wang Yi Current microbiology Recently, several studies have indicated that the intestinal microbiota can be regulated by the individual attributes, and even the alternation of circadian rhythm. Inspired by this, we speculated that seasonal variation might also have some effect on the intestinal microbiota. A total of 11 Sprague-Dawley male rats, weighing 250-280 g, were divided into summer group (n = 5) and winter group (n = 6). Cages were individually ventilated at 20 ± 2 °C and 45-65% relative humidity with a circadian rhythm of 12/12 h. After 1 week of adaptively feeding, mucosal contents of jejunum, terminal ileum, and ascending colon were collected and analyzed by 16S rRNA Gene Amplicon Pyrosequencing. The results showed that intestinal microbiota of rats for the same strain were affected by season change under the same feeding condition and living environment. We should take seasonal factor into account in the future experimental design based on intestinal microbiome. 10.1007/s00284-018-1480-6
Short-term exposure to high relative humidity increases blood urea and influences colonic urea-nitrogen metabolism by altering the gut microbiota. Yin Hongmei,Zhong Yadong,Wang Hui,Hu Jielun,Xia Shengkun,Xiao Yuandong,Nie Shaoping,Xie Mingyong Journal of advanced research Introduction:Colonic urea-nitrogen metabolites have been implicated in the pathogenesis of certain diseases which can be affected by environmental factors. Objectives:We aimed to explore the influence of ambient humidity on colonic urea-nitrogen metabolism. Methods:Blood biochemical indexes, metabolites of intestinal tract, and gut microbiota composition of mice ( = 10/group) exposed to high relative humidity (RH, 90 ± 2%) were analyzed during the 14-day exposure. Results:After 12-h exposure, plasma blood urea nitrogen (BUN) level increased along with a decrease in the activity of erythrocyte Na/K -ATPase. Moreover, abnormal erythrocyte morphologies appeared after 3 days of exposure. The colonic BUN and ammonia levels increased significantly after the 12-h and 24-h exposure, respectively. The colonic level of amino acids, partly synthesized by gut microbiota using ammonia as the nitrogen source, was significantly higher on the 7th day. Furthermore, the level of fecal short-chain fatty acids was significantly higher after 3-day exposure and the level of branched-chain fatty acids increased on the 14th day. Overall, gut microbiota composition was continuously altered during exposure, facilitating the preferential proliferation of urea-nitrogen metabolism bacteria. Conclusion:Our findings suggest that short-term high RH exposure influences colonic urea-nitrogen metabolism by increasing the influx of colonic urea and altering gut microbiota, which might further impact the host health outcomes. 10.1016/j.jare.2021.03.004
Seasonal variation in structure and function of gut microbiota in . Ecology and evolution Gut microbiota is associated with host health and its environmental adaption, influenced by seasonal variation. is one of the world's 100 worst invasive alien species. Here, we used high-throughput sequencing of the 16S rRNA gene to analyze the seasonal variation of gut microbiota of . The results suggested that the predominant gut microbial phyla of included Firmicutes and Proteobacteria, which helped digest plant food and accumulate energy. The gut microbiota of in summer group showed the highest diversity, whereas the winter group possessed the lowest, probably due to the shortage of food resources of in winter. Principal coordinate analysis analysis based on unweighted unifrac and weighted unifrac indicated that the composition of gut microbiota of significantly varied across seasons. Bacteroidetes tended to be enriched in summer by linear discriminant analysis effect size analysis. Actinobacteria and Cyanobacteria were extremely abundant in autumn, while Fusobacteria and enriched in winter. In conclusion, the structure of the gut microbiota of was significantly different among seasons, which was beneficial to the environment adaptation and the digestion and metabolism of food during different periods. 10.1002/ece3.9162
Gut microbiota associated with appetite suppression in high-temperature and high-humidity environments. EBioMedicine BACKGROUND:Food is crucial for maintaining vital human and animal activities. Disorders in appetite control can lead to various metabolic disturbances. Alterations in the gut microbial composition can affect appetite and energy metabolism. While alterations in the gut microbiota have been observed in high-temperature and high-humidity (HTH) environments, the relationship between the gut microbiota during HTH and appetite remains unclear. METHODS:We utilised an artificial climate box to mimic HTH environments, and established a faecal bacteria transplantation (FMT) mouse model. Mendelian randomisation (MR) analysis was used to further confirm the causal relationship between gut microbiota and appetite or appetite-related hormones. FINDINGS:We found that, in the eighth week of exposure to HTH environments, mice showed a decrease in food intake and body weight, and there were significant changes in the intestinal microbiota compared to the control group. After FMT, we observed similar changes in food intake, body weight, and gut bacteria. Appetite-related hormones, including ghrelin, glucagon-like peptide-1, and insulin, were reduced in DH (mice exposed to HTH conditions) and DHF (FMT from mice exposed to HTH environments for 8 weeks), while the level of peptide YY initially increased and then decreased in DH and increased after FMT. Moreover, MR analysis further confirmed that these changes in the intestinal microbiota could affect appetite or appetite-related hormones. INTERPRETATION:Together, our data suggest that the gut microbiota is closely associated with appetite suppression in HTH. These findings provide novel insights into the effects of HTH on appetite. FUNDING:This work was supported by the National Natural Science Foundation of China and Guangzhou University of Chinese Medicine. 10.1016/j.ebiom.2023.104918