Modulatory Effects of Bacillus subtilis on the Performance, Morphology, Cecal Microbiota and Gut Barrier Function of Laying Hens

Abstract

We investigated the efficacy of a single bacterium strain, Bacillus subtilis (B. subtilis) YW1, on the performance, morphology, cecal microbiota, and intestinal barrier function of laying hens. A total of 216 28-week-old Hy-line Brown laying hens were divided into three dietary treatment groups, with six replicates of 12 birds each for 4 weeks. The control group (Ctr) was fed a basal diet and the treatment groups, T1 and T2, were fed a basal diet supplemented with B. subtilis at a dose rate of 5 × 108 CFU/kg and 2.5 × 109 CFU/kg, respectively. Dietary supplementation with B. subtilis did not significantly affect overall egg production in both groups, with no obvious changes in average egg weight and intestine morphology. B. subtilis administration also improved the physical barrier function of the intestine by inducing significantly greater expression levels of the tight junction protein occludin in T1 (p = 0.07) and T2 (p < 0.05). Further, supplementation with B. subtilis effectively modulated the cecal microbiota, increasing the relative level of beneficial bacteria at the genus level (e.g., Bifidobacterium p < 0.05, Lactobacillus p = 0.298, Bacillus p = 0.550) and decreasing the level of potential pathogens (e.g., Fusobacterium p < 0.05, Staphylococcus p < 0.05, Campylobacter p = 0.298). Overall, B. subtilis YW1 supplementation cannot significantly improve the egg production; however, it modulated the cecal microbiota towards a healthier pattern and promoted the mRNA expression of the tight junction protein occludin in laying hens, making B. subtilis YW1 a good probiotic candidate for application in the poultry industry, and further expanding the resources of strains of animal probiotics.

Probiotic Effects of Bacillus licheniformis DSM5749 on Growth Performance and Intestinal Microecological Balance of Laying Hens

“…In this study, the impact of B. licheniformis DSM5749 on the intestinal health of laying hens was investigated by analyzing changes in the microbial composition of the cecum at the phylum and genus levels based on species annotation. At the phylum level, Firmicutes and Bacteroidetes accounted for the largest proportion (>80%) of the total microbial community in the ceca of laying hens, which was consistent with previous findings ( 55 ). Proteobacteria are often overrepresented in metabolic disorders and inflammatory bowel disease, mostly with an inflammatory phenotype ( 55 ).…”

“…At the phylum level, Firmicutes and Bacteroidetes accounted for the largest proportion (>80%) of the total microbial community in the ceca of laying hens, which was consistent with previous findings ( 55 ). Proteobacteria are often overrepresented in metabolic disorders and inflammatory bowel disease, mostly with an inflammatory phenotype ( 55 ). A common trait of Proteobacteria is Gram-negative staining and, thus, the presence of lipopolysaccharide in the outer membrane ( 56 ).…”

Effects of Bacillus subtilis on Production Performance, Bone Physiological Property, and Hematology Indexes in Laying Hens

“…Compared to broilers, laying hens have a longer lifespan with a phase for great egg production, approximately 300 eggs/year or more, therefore, laying hens demand more Ca resulting in depleting structural bone over the course of production, consequently increasing risk of osteoporosis [27]. Some studies have shown that Bacillus subtilis promotes the absorption ability of laying hens by protecting the intestinal barrier and positively regulating intestinal microbiota composition [28,29], and increases egg quality [30,31] and mineral retention [32]. However, few studies have focused on the effects of Bacillus subtilis on bone pathophysiological alterations in aged laying hens and the underlying mechanisms.…”

Cytoprotective Effects of Lactobacilli on Mouse Epithelial Cells during Salmonella Infection

“…We also evaluated dog-isolated Lactobacilli's potential to induce antimicrobial peptide (such as host defensin peptides) production by MODE-K cells, based on previous study of probiotics (LAB) induction of antimicrobial peptides in their hosts [72][73][74][75]. Our results indicated that dog-isolated Lactobacilli-treated MODE-K cell culture supernatant has no antimicrobial activity.…”