Duranti Sabrina, Milani Christian, Lugli Gabriele Andrea, Turroni Francesca, Mancabelli Leonardo, Sanchez Borja, Ferrario Chiara, Viappiani Alice, Mangifesta Marta, Mancino Walter, Gueimonde Miguel, Margolles Abelardo, van Sinderen Douwe, Ventura Marco
Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parma, Italy.
Alimentary Pharmabiotic Centre and Department of Microbiology, Bioscience Institute, National University of Ireland, Cork, Ireland.
Environ Microbiol. 2015 Jul;17(7):2515-31. doi: 10.1111/1462-2920.12743. Epub 2015 Feb 14.
Bifidobacteria are bacterial gut commensals of mammals, birds and social insects that are perceived to influence the metabolism/physiology of their host. In this context, members of the Bifidobacterium bifidum species are believed to significantly contribute to the overall microbiota of the human gut at infant stage. However, the molecular reasons for their adaptation to this environment are poorly understood. In this study, we analysed the pan-genome of B. bifidum species by decoding genomes of 15 B. bifidum strains, which highlighted the existence of a conserved gene uniquely present in this bifidobacterial taxon, underscoring a nutrient acquisition strategy that targets host-derived glycans, such as those present in mucin. Growth experiments and corresponding transcriptomic analyses confirmed the in silico data and supported these intriguing and unique host glycan-specific saccharolytic features. The ubiquity of the genetic features of B. bifidum for the breakdown of host glycans was confirmed by interrogating metagenomic datasets, thereby supporting the notion that metabolic access to host-derived glycans is a potent evolutionary force that has shaped B. bifidum genomes and consequently the ecology of the infant intestinal microbiota.
双歧杆菌是哺乳动物、鸟类和群居昆虫肠道内的共生菌，被认为会影响宿主的新陈代谢/生理机能。在这种情况下，双歧双歧杆菌被认为对婴儿期人类肠道的整体微生物群有显著贡献。然而，它们适应这种环境的分子机制尚不清楚。在本研究中，我们通过解码15株双歧双歧杆菌菌株的基因组来分析该菌种的泛基因组，结果表明存在一个仅在该双歧杆菌分类群中独特存在的保守基因，这突出了一种针对宿主来源聚糖（如粘蛋白中存在的聚糖）的营养获取策略。生长实验和相应的转录组分析证实了计算机模拟数据，并支持了这些有趣且独特的宿主聚糖特异性糖分解特征。通过对宏基因组数据集的研究，证实了双歧双歧杆菌分解宿主聚糖的遗传特征的普遍性，从而支持了这样一种观点，即代谢利用宿主来源的聚糖是一种强大的进化力量，它塑造了双歧双歧杆菌的基因组，进而影响了婴儿肠道微生物群的生态。
