Impact of Intragastric Administration of Donkey Milk on Mouse Immunity Utilizing Gut Microbiomics and Plasma Metabolomics

Jianwen Wang Wanlu Ren Zhiwen Sun Shibo Liu Zixiang Han Yongfa Wang Yaqi Zeng Jun Meng Xinkui Yao ^*

• Xinjiang Agricultural University, Ürümqi, China

Milk and dairy products play critical roles in animal diets and nutrition, but also may exert allergic and other undesirable effects. The influence of donkey milk (DM) on the immunity, gut microbiome, and plasma metabolites of mice was investigated. Immunity analysis revealed that intragastric administration of DM raised the levels of IL-6 and TNF-α cytokines in mouse liver. In addition, DM modulated the composition of both the murine gut microbiome and plasma metabolites. One-hundred and forty-five differentially-produced metabolites were identified, most prominently nicotinamide, L-valine, and β-estradiol, that are primarily associated with valine, leucine, and isoleucine biosynthesis and degradation, nicotinate and nicotinamide metabolism, and unsaturated fatty acid biosynthesis. Alterations at phylum, genus, and species levels were evident in the fecal microbiota of mice after intragastric administration of DM. In particular, an increased abundance of the Lactobacillus bacterium was observed. Correlation analysis of differential metabolites and microbiomes indicated a correspondence between Falsiroseomonas and Salipiger species and the antioxidant coenzyme Q that has the potential to activate the immune system. The data collectively suggest that DM may adjust the murine gut microbiome and plasma metabolites thereby potentially improving immunity in mice.