婴儿源益生性双歧杆菌的筛选及肠道定殖性研究

Screening of Probiotic Bifidobacterium Strains from Infants and Study of Their Intestinal Colonization Ability

摘要:

本研究旨在从婴儿粪便中筛选出具有潜在益生特性的双歧杆菌，并探究其肠道定殖情况，为双歧杆菌的产品开发提供优良的菌株。采用MRS培养基对样品进行分离纯化，菌株经F6PPK检测及16S rDNA测序鉴定，之后进行模拟胃肠液、胆盐耐受性、对食源性致病菌（大肠杆菌、沙门氏菌、单增李斯特菌等）的抑制及对HT-29细胞的粘附能力测定，将筛选出的菌株进行动物实验，测定其肠道定殖能力。分离到的27株双歧杆菌，经分子生物学鉴定为7个不同的种：Bifidobacterium longum、Bifidobacterium breve、Bifidobacterium bifidum、Bifidobacterium pseudocatenulatum、Bifidobacterium infantis、Bifidobacterium animalis和Bifidobacterium adolescentis。体外实验表明，B. longum A9、B. breve A4、B. bifidum B6、B. longum C6、B. adolescentis F8和B. infantis H6等具有较强的潜在益生特性；动物实验表明，B. infantis H6和B. longum C6具有较强的肠道定殖能力。B. longum C6和B. infantis H6有望作为优良的益生性菌株，应用于双歧杆菌的产品开发。

Abstract:

Bifidobacterium strains with potential probiotic properties were screened from infant feces and their colonization ability in the intestine was explored, to provide potential probiotic strains for the development of Bifidobacterium products. De Man, Rogosa, and Sharpe (MRS) medium was used to isolate and purify the samples, and detection of fructose-6-phosphate phosphoketolase (F6PPK) and analysis of 16S rDNA sequences were performed on the strains. The probiotic properties of the strains, including tolerance to simulated gastrointestinal fluids and bile salts, inhibition of foodborne pathogenic bacteria (Escherichia coli, Salmonella spp., Listeria monocytogenes, etc.,) and adhesion capacity to HT-29 cells were determined. The screened Bifidobacterium strains with potential probiotic properties were used in animal experiments to measure their intestinal colonization ability. After isolation, 27 Bifidobacterium strains were identified from seven Bifidobacterium species using molecular biology: Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium bifidum, Bifidobacterium pseudocatenulatum, Bifidobacterium infantis, Bifidobacterium animalis, and Bifidobacterium adolescentis. In vitro experiments showed that B. longum A9, B. breve A4, B. bifidum B6, B. longum C6, B. adolescentis F8, and B. infantis H6 had stronger potential probiotic properties. The animal experiments showed that B. infantis H6 and B. longum C6 had stronger gut colonization ability. The results demonstrate that B. infantis H6 and B. longum C6 have potential as good probiotic Bifidobacterium strains that can be applied to the development of Bifidobacterium products.