The McMaster Brain-Body Institutes, St Joseph's Healthcare, 50 Charlton Ave. East, Hamilton, ON, Canada.
FASEB J. 2010 Oct;24(10):4078-88. doi: 10.1096/fj.09-153841. Epub 2010 Jun 2.
Gut commensals modulate host immune, endocrine, and metabolic functions. They also affect peripheral and central neural reflexes and function. We have previously shown that daily ingestion of Lactobacillus reuteri (LR) for 9 d inhibits the pseudoaffective cardiac response and spinal single-fiber discharge evoked by visceral distension, and decreases intestinal motility and myenteric AH cell slow afterhyperpolarization (sAHP) by inhibiting a Ca-activated K (IK(Ca)) channel. We tested whether luminal LR could acutely decrease motility in an ex vivo perfusion model of naive Balb/c jejunum. Live LR dose dependently decreased motor complex pressure wave amplitudes with 9- to 16-min onset latency and an IC(50) of 5 × 10(7) cells/ml Krebs. Heat-killed LR or another live commensal, Lactobacillus salivarius, were without effect. The IK(Ca) channel blocker TRAM-34, but neither the opener (DCEBIO) nor the hyperpolarization-activated cationic channel inhibitor ZD7288 (5 μM) (or TTX 1 μM), mimicked the LR effect on motility acutely ex vivo. We provide evidence for a rapid, strain-specific, dose-dependent action of a live Lactobacillus on small intestinal motility reflexes that recapitulates the long-term effects of LR ingestion. These observations may be useful as a first step to unraveling the pathways involved in bacteria to the nervous system communication.
肠道共生菌调节宿主的免疫、内分泌和代谢功能。它们还影响外周和中枢神经反射和功能。我们之前已经表明，每天摄入 9 天的罗伊氏乳杆菌（LR）可抑制内脏扩张引起的假性心脏反应和脊髓单纤维放电，并通过抑制钙激活钾（IK（Ca））通道来降低肠道运动和肌间 AH 细胞慢后超极化（sAHP）。我们测试了腔LR 是否可以在离体灌注模型中急性降低小肠的运动。活的 LR 剂量依赖性地降低运动复合压力波幅度，潜伏期为 9-16 分钟，IC（50）为 5×10（7）细胞/ml Krebs。热灭活的 LR 或另一种活共生菌唾液乳杆菌没有作用。IK（Ca）通道阻滞剂 TRAM-34，但 opener（DCEBIO）或 hyperpolarization-activated cationic channel 抑制剂 ZD7288（5 μM）（或 TTX 1 μM）均未模拟 LR 对离体运动的急性作用。我们提供了一种快速、菌株特异性、剂量依赖性的活乳杆菌对小肠运动反射的作用的证据，这种作用重现了 LR 摄入的长期作用。这些观察结果可能有助于作为揭示细菌与神经系统通讯相关途径的第一步。
