Probiotic Bacillus subtilis LF11 Protects Intestinal Epithelium Against Salmonella Infection

Abstract

Enteric diseases caused by Salmonella are prevalent in poultry farming. With the forbiddance of antibiotics in feedstuff industry, Bacillus subtilis (B. subtilis) preparation as antibiotic alternatives against Salmonella infection has gained increasing attention recently. However, the protection modes of B. subtilis against Salmonella infection in broilers are strain-specific. In this study, probiotic B. subtilis LF11 significantly reduced diarrhea and mortality of broilers caused by Salmonella braenderup (S. braenderup) in spite of no inhibition effect on it in vitro. Here, the intestinal epithelial cells NCM460 were incubated to explore the protection of B. subtilis LF11 on intestinal epithelium against Salmonella. The results revealed that B. subtilis LF11 showed obvious exclusion activity with the decrease of adhesion and invasion of S. braenderup to NCM460 cells, accordingly with the increase of NCM460 cell survival compared with S. braenderup challenge alone. Meanwhile, RT-PCR and Western blot proved that the gene transcription and expression levels of four tight junction proteins in NCM 460 cells were upregulated, which was further confirmed by immunofluorescence observation. Besides, B. subtilis LF11 downregulated the gene transcription levels of the proinflammatory cytokines IL-6, IL-8, and TNF-α induced by S. braenderup H9812. ELISA analysis also verified that B. subtilis LF11 reduced the IL-8 production significantly. In general, B. subtilis LF11 has the ability to protect the intestinal epithelium against Salmonella infection by reducing the Salmonella adhesion and invasion, enhancing the intestinal barrier and attenuating the enterocyte inflammatory responses, and has the potential as probiotics to prevent enteric diseases in broilers.

Lysinibacillus macrolides 38328 Isolated from Agricultural Soils as a Promising Probiotic Candidate for Intestinal Health

“…The loss of mice weight is signi cantly inhibited in and 38328 groups compared to the SM group in the anti-Salmonella infection trial. It was reported that anti-Salmonella infection is caused by multiple mechanisms including coaggregation, signal interference, intestinal barrier and bacteriostatic activity [44]. In our results, all Bacillus displayed inhibitory effects against S. typhimurium CVCC541 in vitro, this suggests that the mechanism of the mice against Salmonella infections in vivo may be due to the bacteriostatic activity.…”

Comparative efficacy of a novel Bacillus subtilis-based probiotic and pharmacological zinc oxide on growth performance and gut responses in nursery pigs

“…Intestinal integrity is critical in maintain gut health 52 , especially when morphological changes negatively impact intestinal epithelial barrier during weaning 53 . Previous studies have observed an improved expression of intestinal tight junction genes and improved epithelial barrier function upon supplementation with bacillus-based probiotics 54 – 56 . Higher expression of the intestinal tight junction genes in our study agrees with the previous studies and may help explaining lower diarrhea scoring in the BS9 supplemented group.…”

Evaluation of the Immunity Responses in Mice to Recombinant Bacillus subtilis Displaying Newcastle Disease Virus HN Protein Truncations

“…The morphology of the small intestine directly mirrors the health of the gut, as well as its digestive and absorptive capabilities, which are critical for sustaining the intestinal immune system [ 68 , 69 , 70 ]. Longer villi correlate with epithelial cell proliferation and can stimulate cell mitosis, whereas shorter villi and deeper crypts are associated with nutrient malabsorption and diminished gastrointestinal function [ 71 , 72 , 73 , 74 ]. Our research has determined that dietary supplementation with B. subtilis RH results in an increase in the height of ileal villi and a decrease in crypt depth, thereby enhancing intestinal tissue structure in mice.…”