该研究探讨了动物双歧杆菌乳亚种XLTG11对小鼠肠道的益生作用。将48只BALB/c小鼠适应性喂养7 d后，随机分成空白对照组、XLTG11低剂量组、XLTG11中剂量组和XLTG11高剂量组。其中受试组每只分别灌胃1.6×106、1.6×107和1.6×108 CFU的动物双歧杆菌乳亚种XLTG11菌粉，空白对照组小鼠灌胃等体积的生理盐水。灌胃14 d后，测定小鼠体质量、肠道菌群、组织病理、肠道屏障、肠道通透性和短链脂肪酸含量。结果表明，与空白对照组相比，高剂量组小鼠体质量增加14.51%，小鼠肠道的菌群丰度和菌群结构发生改变，小鼠粪便中双歧杆菌和乳杆菌的数量分别增加29.32%和33.88%，产气荚膜梭菌的数量下降24.49%，并且低、中、高剂量组紧密连接蛋白和黏蛋白的表达量增加，小鼠血清中LPS和D-乳酸含量下降，表明动物双歧杆菌乳亚种XLTG11可以增强肠道屏障功能，降低肠道通透性。此外，小鼠盲肠中短链脂肪酸的含量分别升高13.66%、43.04%、48.58%。综上，该研究表明动物双歧杆菌乳亚种XLTG11能够对小鼠肠道产生健康益处，并对肠道菌群具有调节和改善作用。

The probiotic effects of Bifidobacterium animalis subsp. lactis XLTG11 on the intestinal tract of mice were investigated. After adaptive feeding for seven days, 48 BALB/c mice were randomly divided into a blank control group, XLTG11 low dose group, XLTG11 middle dose group, and XLTG11 high dose group. The three subject groups had B. animalis lactis subspecies XLTG11 bacterial powder gavage, with doses of 1.6×106 CFU/each, 1.6×107 CFU/each, and 1.6×108 CFU/each, respectively. The gavage of the blank control group had an equal volume of saline. After 14 days of gavage, the body mass, intestinal microbiota, histopathology, intestinal barrier, intestinal permeability, and short-chain fatty acid content of mice were measured. The results indicated that, compared to the blank control group, the body mass of mice in the high-dose group increased by 14.51%. Changes occurred to the intestinal microbiota abundance and composition, with the numbers of Bifidobacterium and Lactobacillus in the feces of mice increasing by 29.32% and 33.88%, respectively. The quantity of Clostridium perfringens decreased by 24.49%, and the expression level of tight junction proteins and mucins increased in the low-, medium-, and high-dose groups. The levels of LPS and D-lactic acid in the sera of mice also decreased. These findings indicated that B. animalis subsp. lactis XLTG11 could enhance intestinal barrier function and reduce intestinal permeability. In addition, the levels of short-chain fatty acids in the cecum of mice in the three groups were 13.66%, 43.04%, and 48.58%, respectively. In conclusion, this study demonstrated that B. animalis subsp. lactis XLTG11 could confer health benefits to the intestine in mice and had a regulatory and ameliorative effect on the intestinal microbiota.

中国博士后科学基金面上项目（2022M721071）