Dietary Bacillus spp.enhanced growth and disease resistance of weaned pigs by modulating intestinal microbiota and systemic immunity

Background:Previous research has shown that dietary supplementation of Bacillus spp.probiotics exerts beneficial effects on animals’growth.However,limited studies have evaluated the efficacy of Bacillus spp.on weaned pigs and their effects on host gut health and microbiome,and systemic immunity using a disease challenge model.The objective of this experiment was to investigate the effects of two Bacillus spp.strains(Bacillus subtilis DSM 32540 and Bacillus pumilus DSM 32539)on growth performance,diarrhea,intestinal health,microbiome,and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli(ETEC).Results:Pigs in PRO1(Bacillus subtilis DSM 32540)had greater(P<0.05)body weight on d 7 and 14 PI,greater(P<0.05)ADG from d 0 to 7 and d 7 to 14 PI,compared with pigs in CON(Control).Pigs in PRO1 had milder(P<0.05)diarrhea on d 2 and 3 PI compared with pigs in CON.However,no differences were observed in growth performance and diarrhea score between PRO2(Bacillus pumilus DSM 32539)and CON groups.Supplementation of PRO1 decreased(P<0.05)lymphocyte counts on d 7 and 14 PI,compared with CON.Supplementation of PRO1 and PRO2 both reduced(P<0.05)total coliforms in mesenteric lymph nodes on d 21 PI.Pigs in PRO2 had greater(P<0.05)goblet cell number and sulfomucin percentage in duodenal villi and greater(P<0.05)sialomucin percentage in jejunal villi than pigs in CON.Supplementation of PRO1 up-regulated(P<0.05)MUC2 gene expression in jejunal mucosa and reduced(P<0.05)PTGS-2 and IL1B gene expression in ileal mucosa on d 21 PI,compared with CON.Pigs in PRO1 had reduced(P<0.05)relative abundance of families Lachnospiraceae,Peptostreptococcaceae and Pasteurellaceae in the ileum.Conclusions:Supplementation of Bacillus subtilis DSM 32540 improved growth performance,alleviated diarrhea severity,enhanced gut health,and reduced systemic inflammation of weaned pigs infected with ETEC F18.Although Bacillus pumilus DSM 32539 was able to alleviate systemic inflammation,it had limited impacts on growth performance and severity of diarrhea of ETEC F18 challenged weaned pigs.

Dietary supplementation of sulfur amino acids improves intestinal immunity to Eimeria in broilers treated with anti-interleukin-10 antibody

Oral antibody to interleukin-10(anti-IL-10)enhances the intestinal immune defense against Eimeria.The sulfur amino acids methionine and cysteine(MtC)play essential roles in inducing and maintaining protective immune responses during intestinal infections.Hence,increased dietary MtC may support the anti-IL-10-induced intestinal immunity to Eimeria.Broilers(n=640)were arranged in a 2×2×2 factorial design with 2 levels of each of the 3 main factors:dietary standardized ileal digestible(SID)MtC levels(0.6%or 0.8%),dietary anti-IL-10 supplementation(with or without),and coccidiosis challenge(control or challenge).Briefly,the broilers were supplied with either 0.6%or 0.8%SID MtC,each with or without anti-IL-10(300 mg/kg),from d 10 to 21.On d 14,broilers from each diet were gavaged with either PBS or Eimeria.The resulting Eimeria infection induced fecal oocyst shedding and intestinal lesions.Broilers fed 0.8%SID MtC(main effects,P≤0.05)had decreased feed-to-gain ratio,increased duodenum and cecum luminal anti-Eimeria IgA titers,and decreased fecal oocyst counts,when compared to 0.6%SID MtC.The supplementation of anti-IL-10(main effects,P≤0.05)increased cecum luminal total IgA concentration and decreased cecum lesions.Interactions(P≤0.05)were detected for growth performance and cecum luminal IFN-γ.Briefly,the highest body weight gain and feed intake were reached in PBS-gavaged broilers fed 0.8%SID MtC with no anti-IL-10 and in Eimeria-challenged broilers fed 0.8%SID MtC with anti-IL-10.In Eimeria-infected broilers,anti-IL-10 increased intestinal luminal IFN-γ and body weight gain only at 0.8%SID MtC.Collectively,anti-IL-10 increased intestinal luminal IFN-γ levels,decreased cecum lesions and restored growth only when fed with adequate amounts of sulfur amino acids.Our findings underscore the importance of providing sufficient essential nutrients to support the anti-IL-10 induced immunity against coccidiosis.