Faecal microbiome analysis reveals Clostridiales and Bacteroidales as signature gut microbes during estrus of buffalo

Abstract

The non-pathogenic intestinal microbes that conquer our intestines are not an accidental jumble of organisms, but rather a disparate community of microbes that coexist, and sustain a mutualistic and symbiotic relationship with the host. The gut microbiome has been shown to be influenced by animal physiology and vice versa. However, information is still scanty. The present study aimed to analyse the variation between faecal bacteria of three different stages (proestrus, estrus and postestrus) of the estrous cycle of Murrah buffalos. A phylogenetic study of buffalo faeces derived from three different stages of estrous cycle was conducted in order to compare the bacterial diversity among these three stages. We performed an exploratory microbiome analysis of buffalo faeces using 16S rRNA sequencing during these stages of the buffalo estrous cycle. A total of three bacterial phyla with six different bacterial orders and twenty-three different genera were identified among all the three comparative phases of the estrous cycle. Among them, the Clostridiales were found to be the most abundant, and Bacteroidales were present exclusive during the estrus phase. As faeces is a source of gut microbes and a non-invasive representative of the metabolic steroids and perceptible pheromones, the profiling of gut microbes during estrous cycle would provide clues towards the major microbes contributing to the perceptible pheromones during estrus stage. To the best of our knowledge, this is the first ever report describing the faecal bacterial diversity during estrous cycle of any ruminant species. Although future studies are required to understand the role of Clostridiales and Bacteroidales in faecal pheromone metabolism.