Microencapsulation of a novel Bacteroides thetaiotaomicron strain: a promising strategy to fortify intestinal barrier fortification in a weaned pig model

Porcine Bacteroides thetaiotaomicron LYH5 demonstrated in vitro antimicrobial activity, suggesting probiotic potential. Due to poor gastric juice tolerance, LYH5 was encapsulated via extrusion using sodium alginate (SA) and gellan gum. Box-Behnken design optimization yielded optimal parameters: SA 1.5%, gellan gum 0.4%, CaCl 2 0.9%, bacteria:glue ratio 1:4, achieving an encapsulation rate of 84.22 ± 0.17%. Its effect on weaned piglet intestinal health was evaluated using 78 piglets (7.69 ± 0.52 kg) randomly assigned to four groups for 40 days: CON (control), T (basal diet + LYH5 live bacteria, 1 × 10 10 CFU/mL), TJ (basal diet + LYH5 microcapsules, 1 × 10 10 CFU/mL), J (basal diet + empty capsules). The results of this experiment showed that, compared with the control group, LYH5 microcapsules can improve the intestinal barrier function without affecting the growth performance of piglets, and provide ideas and references for a promising candidate for probiotic development. IMPORTANCE This study addresses the key bottleneck of poor gastric acid tolerance of probiotics via microencapsulation and provides a practical reference for a promising candidate for probiotic development.