Polyphenol-rich feed material increases Anaerostipes and reduces methanogenic Archaea in the horse hindgut microbiome

The gastrointestinal microbiota plays a critical role in horse health and performance. While sugarcane-derived polyphenols have shown microbiota-modulating properties in other species, their effects in horses remain unexplored.

This study investigated whether supplementation with a sugarcane-derived polyphenol feed material modulates the hindgut microbiota of healthy adult horses.

An observational longitudinal study was conducted on six horses over 12 weeks. Faecal samples were collected at three time points: baseline (P1), during supplementation (P2), and post-supplementation (P3). Microbial composition was assessed by 16S rRNA gene sequencing targeting the V3-V4 region. Alpha and beta diversity, as well as differential abundance analyses, were performed.

Alpha diversity metrics (Chao1, Shannon, Simpson) showed no significant differences across time points. However, Anaerostipes increased by 105.3% during supplementation and 23.6% post-supplementation. Prevotella abundance also rose post-supplementation. Methanogenic Archaea, including Methanomassiliicoccus, decreased by 79.1% during supplementation, while members of Methanobacteriales were reduced by 61.8%. These changes partially reversed in the post-supplementation phase. Core microbiota genera remained stable throughout.

Supplementation with a sugarcane-derived polyphenol feed material modulated specific microbial taxa without disrupting overall microbial diversity. The intervention enhanced fermentative SCFA-producing bacteria and suppressed methanogenic Archaea, supporting the potential use of this feed material as a microbiome enhancer for improving hindgut health and reducing methanogenesis in horses.