纳米包被猪源枯草芽孢杆菌PB58的环境耐受性及其对小鼠肠道健康的改善作用OA

This study aimed to investigate the environmental tolerance of nano-coated porcine-derived Bacillus subtilis PB58 and its effects on intestinal morphology,microbiota and metabolites of mice.Using nano-metal coating technology,trivalent iron ions(Fe3+),tannic acid and ferulic acid were selected for multilayer coating of porcine-derived Bacillus subtilis PB58 to prepare PB58-iron-tannic acid-ferulic acid-coated nanoparticles.The coating effect was observed by scanning electron microscopy,and the environmental tolerance of the coa-ted PB58 was evaluated.Twelve specific pathogen-free(SPF)male BALB/c mice were randomly divided into two groups:the control group received 200 μL of LB liquid medium daily by gavage,and the coated group re-ceived 200 μL of coated PB58 bacterial suspension(1×1011 CFU/mL,suspended in LB liquid medium)daily by gavage.After 25 days of gavage,indicators such as growth performance,health status and intestinal micro-biota of the mice were measured.The results showed that the coating system consisting of 10 mg/mL ferric chloride solution,30 mg/mL tannic acid solution and 4 mg/mL ferulic acid solution exhibited no toxicity to PB58.Compared with the control group,the coated group showed significantly increased survival rates under culture conditions of acidity,bile salts,high temperature,simulated gastrointestinal fluids,and ampicillin(P＜0.05).Compared with the control group,the coated group exhibited significantly increased average daily gain,average daily feed intake,and serum content of interleukin-10(IL-10)and interleukin-22(IL-22)(P＜0.05),while serum tumor necrosis factor-α(TNF-α)content was significantly decreased(P＜0.05).Addi-tionally,liver index,colon length,and intestinal microbiota α diversity indices(Ace,Chao1 and Shannon in-dices)were significantly increased(P＜0.05),ileal villus length was increased,and the abundance of Firmi-cutes was enhanced in the coated group.Compared with the control group,the enriched differential metabolites in the intestine of mice in the coated group were L-valine,cinncassiol D4 2-glucoside,cis-4-carboxymethylene-but-2-en-4-olid and hulupon.Among these,L-valine,which was enriched in the pantothenate and coenzyme A biosynthesis pathway,showed a significant positive correlation with Eubacterium_coprostanoligenes_group,a bacterium belonging to the Firmicutes(P＜0.05).In conclusion,the iron-tannic acid-ferulic acid coating sys-tem effectively can enhance the environmental tolerance of porcine-derived Bacillus subtilis PB58.After inter-vention with coated PB58,the health indicators,intestinal morphology,and composition of intestinal microbio-ta and metabolites in mice are improved.Therefore,coated PB58 has the potential to replace antibiotics as a functional probiotic for improving animal intestinal health.[Chinese Journal of Animal Nutrition,2026,38(5):3763-3778]