Blastocystis infection enhances vitamins B and K2 biosynthesis in the Tibetan antelope (Pantholops hodgsonii) gut microbiota

The gut microbiota of the Tibetan antelope (Pantholops hodgsonii) plays a vital role in host nutrition, particularly by contributing to the biosynthesis of essential micronutrients such as vitamins B and K2. In this study, we integrated existing P. hodgsonii gut metagenome-assembled genomes with healthy and Blastocystis-infected gut metagenomic samples to investigate microbial strategies for vitamins B and K2 production, as well as the potential modulation of these biosynthetic pathways in the gut of P. hodgsonii. From a total of 33,925 metagenome-assembled genomes, we identified 14,549 non-redundant genomes encoding 182 KEGG orthologs linked to vitamin biosynthesis. Among these, 2,115 high-quality genomes were predicted to synthesize at least one vitamin de novo, yet only 2.9% could produce four or more vitamins. Comparative analyses across multiple host species, including humans, chickens, cats, and mice, revealed that members of the phyla Bacillota_A and Bacteroidetes consistently serve as primary contributors to microbial vitamin biosynthesis. Blastocystis infection was associated with a significant increase in the abundance and diversity of vitamin biosynthesis genes, reflecting adaptive shifts in microbial metabolism. Detailed genomic analyses of the thiamine biosynthesis pathway highlighted the core contributions of Bacillota_A, Bacteroidota, Verrucomicrobiota, and Methanobacteriota, underscoring complex taxonomic cooperation. These results provide novel insights into the functional specialization and taxonomic composition of the P. hodgsonii gut microbiota, offering novel insights into microbial adaptation and metabolic cooperation that support host nutritional homeostasis and resilience in extreme environments.