• 肠道菌群的内部合作对其生态系统十分重要;
  • 本文研究拟杆菌目内部合作的进化;
  • 多型拟杆菌在某种食物多糖中生长时只有有限的合作;
  • 相比之下,肠道共生的卵形拟杆菌中在多糖中生长时,存在着一种专业的交互共生酶系统;
  • 卵形拟杆菌胞外消化菊粉后的产物可供普通拟杆菌利用。
蓝灿辉 | 热心肠先生
Nature [IF:43.07]

The evolution of cooperation within the gut microbiota



2016-04-25, Letter

Abstract & Authors:展开

Cooperative phenotypes are considered central to the functioning of microbial communities in many contexts, including communication via quorum sensing, biofilm formation, antibiotic resistance, and pathogenesis. The human intestine houses a dense and diverse microbial community critical to health, yet we know little about cooperation within this important ecosystem. Here we test experimentally for evolved cooperation within the Bacteroidales, the dominant Gram-negative bacteria of the human intestine. We show that during growth on certain dietary polysaccharides, the model member Bacteroides thetaiotaomicron exhibits only limited cooperation. Although this organism digests these polysaccharides extracellularly, mutants lacking this ability are outcompeted. In contrast, we discovered a dedicated cross-feeding enzyme system in the prominent gut symbiont Bacteroides ovatus, which digests polysaccharide at a cost to itself but at a benefit to another species. Using in vitro systems and gnotobiotic mouse colonization models, we find that extracellular digestion of inulin increases the fitness of B. ovatus owing to reciprocal benefits when it feeds other gut species such as Bacteroides vulgatus. This is a rare example of naturally-evolved cooperation between microbial species. Our study reveals both the complexity and importance of cooperative phenotypes within the mammalian intestinal microbiota.

First Authors:
Seth Rakoff-Nahoum

Correspondence Authors:
Seth Rakoff-Nahoum

All Authors:
Seth Rakoff-Nahoum,K R Foster,Laurie E Comstock