Bile-induced biofilm formation in Bacteroides thetaiotaomicron requires magnesium efflux by an RND pump

The study is about the role of Bacteroides thetaiotaomicron in the human gut microbiota, specifically its ability to form biofilms in response to bile salts. The study found that bile induces the expression of certain efflux pumps, and inhibiting these pumps impairs biofilm formation. Among the induced pumps, the BipABC pump is crucial for biofilm formation as it is involved in the efflux of magnesium, which affects the biofilm's extracellular matrix and structure. This discovery sheds light on how intestinal chemical cues, like bile salts, regulate biofilm formation in B. thetaiotaomicron, a significant gut symbiont.

本研究聚焦多形拟杆菌（Bacteroides thetaiotaomicron）在人类肠道微生物群中的作用，重点探究其响应胆汁盐形成生物膜（biofilm）的能力。研究发现，胆汁可诱导特定外排泵（efflux pump）的表达，而抑制此类外排泵会削弱生物膜的形成能力。在被诱导的外排泵中，BipABC泵对生物膜形成至关重要，因其参与镁离子的外排过程，该过程会影响生物膜的细胞外基质与整体结构。这一发现揭示了肠道化学信号（如胆汁盐）如何调控多形拟杆菌——一种重要的肠道共生菌——的生物膜形成机制。