【摘要】 双歧杆菌被认为是肠道内的有益菌,可以利用膳食中的多种植物多糖或寡糖,能够被人体无法消化的复杂碳水化合物选择性富集。本研究采用序列引导的分离策略,于厌氧条件下采用MRS琼脂培养基,得到了一名肥胖儿童营养干预后肠道内优势的双歧杆菌。采用ERIC指纹图谱技术对分离物进行基因水平上的分型,并通过16S r RNA基因测序鉴定分离株的分类地位。73个双歧杆菌分离物分为5种ERIC类型,均为假小链双歧杆菌。与Bacteroides thetaiotaomicron ATCC 29148、Eschrichia coli D45和Anaerostipes hadrus BPB5这些肠道中常见共生菌的代表菌株相比,丰度最高的ERIC类型代表菌株Bifidobacterium pseudocatenulatum C95利用复杂碳水化合物的能力更强。Bifidobacterium pseudocatenulatum C95被膳食中的复杂碳水化合物和益生元显著富集,成为该儿童营养干预后肠道内的优势菌。菌株自身较强的碳水化合物利用能力可能是其生长优于肠道中其他共生细菌的原因。更多还原

【Abstract】 B ifidobateria has been considered as beneficial bacteria and can utilize various plant derived oligoand polysaccharides in diet, which can be selectively enriched by a variety of non-digest carbohydrates. In this study, using sequencing-guided isolation scheme, we obtained Bifidobateria isolates from the post-intervention fecal sample of a morbidly obese child with MRS Agar medium under anaerobic condition. Enterobacterial Repetitive Intergenic Consensus(ERIC)-PCR was used as genomic fingerprinting technology for classification of bacterial isolates. 73 Bifidobacteria isolates were classified into 5 ERIC types, all belonging to Bifidobacterium pseudocatenulatum through 16 S r RNA gene sequencing. Compared to Bacteroides thetaiotaomicron ATCC 29148,Eschrichia coli D45 and Anaerostipes hadrus BPB5, the representative strain of ERIC type with highest abundance—Bifidobacterium pseudocatenulatum C95 had significantly stronger ability to utilize complex carbohydrates. In summary, Bifidobacterium pseudocatenulatum C95 was significantly stimulated by a diet composed of complex carbohydrates and prebiotics, which became the predominant strain of this child’s gut after dietary intervention. Its strong carbohydrate utilization capacity contributed to the superiority to other intestinal symbiotic strains.更多还原