The effect of melatonin on the structure of rumen microbiota. sheep gut metagenome

Melatonin (MLT), an amine hormone, can be synthesized and secreted in cells and gastrointestinal tract. Among them, MLT from gastrointestinal sources can regulate gastrointestinal movement, improve the antioxidant capacity, and increase the immune regulation of the body. MLT can be used as a signal molecule to participate in the communication between intestinal microorganisms, and to affect the microbial community structure and its metabolites by releasing cellular regulatory factors. Intestinal bacteria recognized and responded to MLT signals from the intestine through MLT binding sites, further activating the function of intestinal immune cells. A study about the effects of MLT on the gut microbiota showed that gut microbes can determine the effects of Trp on the body through pronounced changes in amino acid metabolites, such as bacteria that produce indole sulfate and indole-3-propionic acid (IPA). The formation of IPA is entirely dependent on gut microbes, and can be enhanced by colonization with Clostridium sporogenes. MLT can also pass NF-κB channel where it regulates intestinal microorganisms and their metabolism, and affect the population structure of animal intestinal microorganisms. However, the signal transduction pathway of MLT in rumen and their interacting microorganisms in MLT metabolism are unknown. Therefore, we proposed a hypothesis that MLT had a direct or indirect impact on changes in rumen microbiota and metabolites. In our study, mixed rumen microorganisms were cultured by in vitro culture technology along with MLT to explore the effects on rumen microbial flora and metabolic reactions.