Effect of calf separation on gut microbiome and fecal metabolome of mother in the captive Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis).

Social separation, or the absence of social support, can cause physical and psychological health issues. Social separation is crucial for the welfare of the Yangtze finless porpoise (YFP) in captivity because they face many challenges like frequent social separation, noise from visitors, and animal replacement, which can cause psychological and physiological stress. This research is aimed at assessing the potential negative impacts of social separation on the gut microbiome and metabolome of captive YFP, focusing on the potential imbalances caused by mother-calf separation. The study found that social separation did not alter the alpha and beta diversity of the gut microbes but increased the abundance of disease-associated taxa such as Romboutsia, Terrisporobacter, and Clostridium_sensu_stricto_13 in the MC (mother-calf) group while increasing Paeniclostridium and Clostridium_sensu_stricto_1 associated with host health in the MS (mother-separated) group. The fecal metabolome underwent significant changes during social separation, with stress-associated metabolites like kainic acid, phenethylamine glucuronide, and paxilline upregulated in the MC group and host health-associated metabolites like butyric acid, 6-hydroxyhexanoic acid, and fosinopril downregulated in the MS group. In addition, there was a strong association between the fecal microbiome and the metabolome of captive YFPs. The study enhances our comprehension of the detrimental effects of social separation, which result in disruptions in the gut microbiome and fecal metabolome. The study is aimed at introducing a new method for assessing the health and welfare of endangered mammals in captivity.