1Department of Food Science, University of Massachusetts, Amherst, MA, USA.
2Molecular and Cellular Biology Program, University of Massachusetts, Amherst, MA, USA.
Microb Genom. 2018 Jun;4(6). doi: 10.1099/mgen.0.000183. Epub 2018 Jun 15.
Bifidobacterium is a diverse genus of anaerobic, saccharolytic bacteria that colonize many animals, notably humans and other mammals. The presence of these bacteria in the gastrointestinal tract represents a potential coevolution between the gut microbiome and its mammalian host mediated by diet. To study the relationship between bifidobacterial gut symbionts and host nutrition, we analyzed the genome of two bifidobacteria strains isolated from the feces of a common marmoset (Callithrix jacchus), a primate species studied for its ability to subsist on host-indigestible carbohydrates. Whole genome sequencing identified these isolates as unique strains of Bifidobacterium callitrichos. All three strains, including these isolates and the previously described type strain, contain genes that may enable utilization of marmoset dietary substrates. These include genes predicted to contribute to galactose, arabinose, and trehalose metabolic pathways. In addition, significant genomic differences between strains suggest that bifidobacteria possess distinct roles in carbohydrate metabolism within the same host. Thus, bifidobacteria utilize dietary components specific to their host, both humans and non-human primates alike. Comparative genomics suggests conservation of possible coevolutionary relationships within the primate clade.
双歧杆菌是一类厌氧、可发酵糖的细菌，广泛存在于许多动物体内，特别是人类和其他哺乳动物。这些细菌在胃肠道中的存在代表了肠道微生物组与其哺乳动物宿主之间通过饮食介导的潜在共同进化。为了研究双歧杆菌肠道共生体与宿主营养之间的关系，我们分析了从普通狨猴（Callithrix jacchus）粪便中分离得到的两株双歧杆菌菌株的基因组，普通狨猴是一种研究其能够利用宿主不可消化碳水化合物的能力的灵长类动物。全基因组测序将这些分离株鉴定为双歧杆菌 callitrichos 的独特菌株。包括这些分离株和之前描述的模式株在内的所有三个菌株都含有可能使其利用狨猴饮食底物的基因。其中包括预测对半乳糖、阿拉伯糖和海藻糖代谢途径有贡献的基因。此外，菌株之间的显著基因组差异表明双歧杆菌在同一宿主的碳水化合物代谢中具有不同的作用。因此，双歧杆菌利用其宿主（包括人类和非人类灵长类动物）特有的饮食成分。比较基因组学表明，灵长类动物中可能存在共同进化关系的保守性。
