动物双歧杆菌乳亚种XLTG11对克林霉素诱导的抗生素相关性腹泻的改善作用

Alleviative Effect of Bifidobacterium animalis subsp.lactis XLTG11 on Antibiotic-Associated Diarrhea Induced by Clindamycin

目的:通过克林霉素诱导抗生素相关性腹泻(antibiotic-associated diarrhea,AAD)模型,探究动物双歧杆菌乳亚种XLTG11缓解小鼠AAD的作用。方法:将48只6周龄C57BL/6N雄鼠随机分为4组:对照组、模型组、低剂量组和高剂量组,除对照组外,各组小鼠连续14 d灌胃克林霉素(250 mg/(kg mb·d))诱导AAD模型,然后低剂量组和高剂量组灌胃不同剂量(0.2 mL,5×10^(6)、1×10^(7)CFU)动物双歧杆菌乳亚种XLTG11,测定小鼠体质量增长量、盲肠质量、粪便含水量和粪便稠度,测定结肠肿瘤坏死因子α、白细胞介素6(interleukin 6,IL-6)、IL-1β、IL-10水平,血清脂多糖(lipopolysaccharide,LPS)和D-乳酸质量浓度,测定肠道菌群组成及短链脂肪酸含量,以及肠道屏障和核因子κB(nuclear factor kappa-B,NF-κB)信号通路相关基因表达水平。结果:高剂量动物双歧杆菌乳亚种XLTG11显著提高AAD模型小鼠的体质量增长量和抗炎细胞因子水平(P<0.05),显著降低盲肠质量、粪便含水量、粪便稠度评分、促炎细胞因子水平、血清LPS和D-乳酸质量浓度(P<0.05),显著上调闭锁小带蛋白1、Occludin、Claudin-1和黏蛋白2基因的表达水平,调节肠道菌群组成,粪便中乙酸、丙酸和丁酸含量显著增加,显著下调Toll样受体4(Toll like receptor 4,TLR4)、髓分化因子88(myeloid differentiation factor 88,MyD88)和NF-κB信号通路相关基因的表达水平。结论:动物双歧杆菌乳亚种XLTG11能够改善AAD模型小鼠腹泻相关指标,调节细胞因子和肠道菌群组成,提高短链脂肪酸含量,提高肠道屏障相关基因的表达和抑制TLR4/MyD88/NF-κB信号通路的激活,进而有效缓解克林霉素诱导的AAD。

Objective:To investigate the relieving effect of Bifidobacterium animalis subsp.lactis XLTG11 on antibioticassociated diarrhea(AAD)in mice using clindamycin-induced AAD model.Methods:Forty-eight 6-week-old C57BL/6N male mice were randomly divided into four groups:normal control,model,low-dose and high-dose XLTG11.All mice except for the control group were administered with clindamycin orally daily for 14 days to induce AAD,The low-dose and high-dose groups were given 0.2 mL of the bacterial suspensions with viable count of 5×10^(6)and 1×10^(7)CFU,respectively.Body mass gain,cecum mass,fecal water content and fecal consistency score were measured.The levels of tumor necrosis factorα(TNF-α),interleukin 6(IL-6),IL-1β,and IL-10 in cecum tissue and the serum levels of lipopolysaccharide(LPS)and D-lactic acid were determined.The gut microbiota composition and the fecal contents of short-chain fatty acids were detected.The expression levels of genes related to the intestinal barrier and the nuclear factor kappa-B(NF-k B)pathway were determined.Results:The high dose of Bifidobacterium animalis subsp.lactis XLTG11 significantly increased the body mass gain and anti-inflammatory cytokine levels(P<0.05),and significantly decreased cecum mass,fecal water content,fecal consistency score and proinflammatory cytokine levels in the mouse model mice of AAD.Moreover,it significantly up-regulated the gene expression levels of ZO-1,occludin,claudin-1 and MUC2,regulated the composition of the gut microbiota,evidently increased the fecal contents of acetate,propanoate,and butanoate,and significantly down-regulated the expression levels of genes related to the Toll like receptor 4(TLR4),myeloid differentiation factor(MYD88)and NF-κB signaling pathway.Conclusion:Bifidobacterium animalis subsp.lactis XLTG11 can effectively alleviate AAD symptoms in mice by regulating cytokines and the gut microbiota,increasing fecal short-chain fatty acid contents,increasing the expression levels of intestinal barrier related genes and inhibiting the activation of the TLR4/My D88/NF-k B signaling pathway.