Astragalus Polysaccharides Ameliorate Perinatal Metabolic Syndrome in Sows via Enhancing Butyrate-Producing Bacteria

Astragalus polysaccharide (APS), a bioactive phytomacromolecule from Astragalus membranaceus, exhibits anti-inflammatory, antioxidant, and immunomodulatory activities. Given mammals' lack of endogenous glycosidases for APS catabolism, this study hypothesizes its bioactivity stems from gut microbial interactions, investigating APS-mediated microbiome remodeling and therapeutic effects on perinatal metabolic syndrome (PeriMS) in sows. In vitro fermentation showed APS significantly increased short-chain fatty acid (SCFA) production, with acetate (44.51 mmol/L), propionate (17.37 mmol/L), and butyrate (22.04 mmol/L) levels notably elevated, and enriched butyrate-producing taxa (g_norank_f_Muribaculaceae, g_Monoglobus, g_unclassified_f_Lachnospiraceae, P < 0.05). In vivo, gestational APS supplementation (from day 90) improved piglet weaning weight, reduced maternal backfat loss during lactation, shortened post-weaning estrus interval, elevated intestinal butyrate, alleviated systemic inflammation/oxidative stress, and mitigated PMS. Mechanistic analysis linked PeriMS improvement to butyrate-producing bacteria, with butyrate playing a key role in gut health enhancement. These findings establish APS as a prebiotic, highlighting the gut microbiota-SCFA axis as a therapeutic target for PeriMS. This work provides the first evidence of the microbiota-SCFA axis in metabolic syndrome intervention in sows, offering translational strategies to improve livestock metabolic health through APS supplementation.