A probiotic Brevibacillus laterosporus promotes chicken growth performance immunity and gut health

This study evaluated Brevibacillus laterosporus (PBC01) on growth performance, immunity and intestinal health of male Lohmann Brown laying chickens. A total of 144 7-day-old chickens were randomly assigned to four dietary treatments: a basal diet supplemented with 0%, 0.10%, 0.25%, or 0.50% (w/w) B. laterosporus PBC01 powder (1.0 × 10⁹ cfu/g), designated as negative control group (NC), low-dose group (BL), medium-dose group (BM), and high-dose group (BH), respectively. Each group was fed the corresponding experimental diet for 56 days. Results showed that supplementally feeding with 0.25% PBC01 (BM) could enhance the chicken's antioxidant capacity and improve body weight gain and and optimized the feed conversion ratio throughout the experimental period. PBC01 also promoted the relative weight of immune organs, enhanced lymphocyte conversion in peripheral blood and reduced the mRNA expression of IL-2, IL-4, IL-6, TNF-α in spleen. In addition, dietary with PBC01 enhanced cellulase and protease activity in the jejunum; It can lengthen the villi height, reduce the depth of the crypts, improve the intestinal morphology, enhance the intestinal viability, and also enhance the tight links of cells. Moreover, PBC01 also showed beneficial effects in sustaining chicken's microbiota homeostasis by increasing the number of beneficial bacteria and reducing the pathogenic bacteria. In conclusion, this study showed that 0.25-0.50% supplementation of PBC01effectively improved antioxidant status, immune response, intestinal environment, and growth performance in male laying chickens, demonstrating its potential as a functional probiotic strain.