Host-driven remodeling of rumen microbiota supports lactation metabolism in buffalo

DING ZIXU^1,2Yixue Xu³Yan Wang³Miaoer Liu³Peng Zhu⁴Kuiqing Cui¹Chunyan Yang⁵Changlong Xu⁶Tong Feng⁷Qingyou Liu^1*

• ¹Foshan University, Foshan, Guangdong Province, China
• ²South China Agricultural University, Guangzhou, Guangdong Province, China
• ³Guangxi University, Nanning, Guangxi Zhuang Region, China
• ⁴Beibu Gulf University, Qinzhou, China
• ⁵Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning, Guangxi Zhuang Region, China
• ⁶Nanning Second People's Hospital, Nanning, Guangxi Zhuang Region, China
• ⁷Huazhong University of Science and Technology, Wuhan, Hubei Province, China

Rumen microbiota and host metabolites collectively influence the production performance and physiological adaptation of ruminants. This study employed multi-omics integration to investigate host-driven microbial remodeling and metabolic adaptations in buffaloes between lactation and dry periods. Metagenomic analysis revealed significantly increased abundances of genera such as Anaerovibrio, Succiniclasticum, and Methanobrevibacter_A during lactation, which are associated with lipid hydrolysis, propionate production, and methanogenesis, respectively. The lactation period was characterized by an enrichment of glycoside hydrolases, including GH2, GH3, GH5, and GH13, suggesting an increased potential for carbohydrate degradation. In contrast, Butyrivibrio, Fibrobacter, and Eubacterium_Q were predominant during the dry period, contributing to fiber degradation and butyrate synthesis. Functional pathway analysis further showed that pathways related to niacin metabolism, bicarbonate reabsorption, and neuroactive ligand-receptor interaction were elevated during lactation, supporting mammary gland function, acid-base balance, and endocrine regulation.Serum metabolomics identified lactation-associated enrichment of metabolites such as indole-3-methylacetate, D-maltose, and gluconic acid, which were significantly correlated with immune and metabolic indicators including IgA, glucose, and LDL. In contrast, dry-period metabolites such as 1-methylhistidine and 5-hydroxyindoleacetic acid suggested a shift toward tissue repair, stress alleviation, and nutrient conservation.Integrative analysis revealed that host physiological demands during lactation coordinate rumen microbial restructuring to prioritize triglyceride degradation, fatty acid biosynthesis, and energy utilization, thereby promoting milk synthesis. These findings highlight a host-directed microbiome-metabolite axis that provides novel insights into the molecular mechanisms regulating lactation in buffaloes.