Changes in Fecal Microbiota During Estrous Cycle in Healthy Thoroughbred Mares

Gut microbiota is associated with numerous physiological processes, including the reproductive system and steroid sex hormones. During the normal estrus cycle of healthy mares, the concentration of estradiol and progesterone in the blood will show periodic changes. To explore the relationship between cyclic changes in steroid sex hormones and mare gut microbiome, we investigated the composition of the fecal microbiota in healthy mares during the normal estrus cycle and its relationship to hormone levels to understand whether sex hormones level is factors affecting the gut microbiome community in mares. The richness and main composition of gut microbiota did not change significantly during the normal estrous cycle in healthy mares. During designed Certain bacteria with low relative abundance exhibit a correlation with changes in blood hormone levels. The LEFSE analysis on the microbial composition of the follicular phase and luteal phase showed differentially abundant 8 Rhodococcus genus. This study reveals that the major composition of mare gut microbiota remains stable throughout the complete estrous cycle, and the changes of several low abundance pathogenic bacteria were correlated with the sexual hormonal fluctuations during the estrous cycle.