Gastrointestinal microbial nitrogen metabolism shapes nitrogen use efficiency in goats fed soybean meal vs. corn gluten meal (microbiomejournal.biomedcentral.com)

• SBM diet improved growth and nitrogen efficiency in goats.
• SBM enriched protein-degrading bacteria and peptidase genes in the rumen.
• CGM diet promoted proteolytic Alistipes in the colon and upregulated amino acid biosynthesis genes.
• Microbial compensation for dietary amino acid deficiency was insufficient.

"A study published in Microbiome on 20 April 2026 by researchers at the Chinese Academy of Sciences compared nitrogen utilization efficiency in goats fed soybean meal (SBM) or corn gluten meal (CGM). Goats on SBM showed higher growth, digestibility, and free amino acids. SBM enriched rumen bacteria that degrade protein (Sodaliphilus, Limivicinus, RUG472) and upregulated peptidase genes. CGM, with more rumen-undegradable protein, promoted proteolytic Alistipes in the colon and enriched amino acid-producing bacteria (Ruminococcus, Treponema, others) with increased de novo biosynthesis genes for aromatic amino acids, lysine, and histidine, though insufficient to fully compensate for dietary deficiencies. The study maps microbial nitrogen metabolic pathways and identifies potential targets for improving nitrogen use in ruminants."