Goat-derived Lactobacillus amylovorus improved floppy kid syndrome via regulating gut microflora.

Abstract

BACKGROUND: Floppy Kid Syndrome (FKS) severely restricts goat farming due to high mortality from metabolic disturbances and gut dysbiosis. Here, we aimed to isolate a goat-derived probiotic and evaluate its capacity to restore gut homeostasis in FKSaffected goats. RESULTS: Lactobacillus amylovorus isolates was obtained via selective colony morphology, Gramstain and catalase testing, and confirmed by 16&#xa0;S rRNA sequencing (&#x2265;&#x2009;98% identity). The isolate survived at pH 2.0 (72%) and pH 3.0 (85%), tolerated 0.3% bile salts (survival&#x2009;>&#x2009;10%), and retained&#x2009;>&#x2009;40% viability after 60&#xa0;s at 60&#xa0;&#xb0;C. In disk diffusion assays, inhibition zones averaged 16&#xa0;mm against Escherichia coli and 12&#xa0;mm against Staphylococcus aureus. In FKSaffected goats receiving 1&#x2009;&#xd7;&#x2009;10CFU/day for 3 days, Shannon diversity increased by 25% (p&#x2009;<&#x2009;0.05), Simpson index by 18% (p&#x2009;<&#x2009;0.05), and shared species with healthy controls rose from 8 to 17. Relative abundance of EscherichiaShigella declined by 40%, while Lactobacillus and Ruminococcus increased by 30% and 22%, respectively (p&#x2009;<&#x2009;0.05). CONCLUSIONS: Goat-derived L. amylovorus displays robust acid, bile and heat tolerance, inhibits key pathogens, and effectively regulates gut microbiota in FKSaffected goats. These findings support its promise as a novel probiotic intervention for preventing and treating Floppy Kid Syndrome.