胰高血糖素样肽-1(glucagon-like peptide 1,GLP-1)是一种由肠道内分泌细胞产生的具有血糖调节作用的肠促胰岛素激素,肠道内乳杆菌(Lactobacillus)可能影响其分泌。该研究采用简单易操作的体细胞(有氧)-黏液层-细菌(微需氧)共培养体系分析3种乳杆菌[鼠李糖乳杆菌(L.rhamnosus)、植物乳杆菌(L.plantarum)和约翰氏乳杆菌(L.johnsonii)]对肠道内分泌细胞GLP-1分泌的影响。同时研究了菌株的剂量效应以及O2和黏液层对共培养系统的影响。结果显示,1×109、1×108、1×107 CFU/1 000 mL的L.rhamnosus可增加细胞GLP-1的分泌。低浓度的L.plantarum和L.johnsonii(<1×107 CFU/1 000 mL)不影响细胞GLP-1产生,但在浓度高于1×108 CFU/1 000 mL时则会显著降低(P<0.05)GLP-1的分泌。黏液层是存在于肠道细胞与微生物间的重要屏障,黏液层缺失会显著降低(P<0.05)共培养体系中细胞GLP-1分泌。但O2对不同细菌的共培养体系的影响存在差异,当与L.rhamnosus和L.plantarum共培养时,有限的O2条件对细胞的GLP-1分泌没有影响,但当与L.johnsonii共培养时则会显著降低(P<0.05)GLP-1的分泌。该研究采用设备要求低、操作简单的共培养体系模拟体内环境,确定了黏液层在共培养体系中的重要性;证实了L.rhamnosus可促进肠道内分泌细胞GLP-1的分泌;同时发现不同乳杆菌菌株对GLP-1的影响不同,并存在剂量效应。研究将为阐释益生菌与体细胞互作提供新的方法参考,为乳杆菌调节GLP-1代谢提供科学依据。
Glucagon-like peptide 1 (GLP-1) is an intestinal incretin hormone that regulates blood glucose levels and is produced by enteroendocrine cells.Intestinal Lactobacilli may affect its secretion.In this study, a simple co-culture system consisting of aerobic cells, mucous layer, and bacteria (microaerobic) was used to analyze the effect of three lactobacilli strains (L.rhamnosus, L.plantarum, and L.johnsonii) on GLP-1 secretion by enteroendocrine cells.The dose effect of the strains and the influence of oxygen and mucous layer on the co-culture system were also investigated.Results showed that L.rhamnosus at concentrations of 1×109, 1×108, and 1×107 CFU/1 000 mL could increase the secretion of GLP-1 by cells.Low concentrations of L.plantarum and L.johnsonii (< 1×107 CFU/1 000 mL) did not affect GLP-1 production, but at concentrations higher than 1×108 CFU/1 000 mL, they significantly decreased (P<0.05) the secretion.The mucous layer is an important barrier between intestinal cells and microbes.Its absence significantly reduced (P<0.05) the secretion of GLP-1 in the co-culture system.However, the effects of limited oxygen conditions on co-culture systems with different bacteria strains differed.When co-cultured with L.rhamnosus and L.plantarum, the limited oxygen conditions had no effect on GLP-1 secretion, but when co-cultured with L.johnsonii, it significantly decreased (P<0.05) the secretion.This study utilized a co-culture system with simple operation and low equipment requirements to mimic the in vivo environment.The significance of the mucus layer in this system was demonstrated.Moreover, it was confirmed that L.rhamnosus promotes the secretion of GLP-1 by enteroendocrine cells.The study also revealed that different strains of lactobacilli have distinct effects on GLP-1 and that there is a dose-effect relationship.The research provides a new method reference for explaining the interaction between probiotics and body cells and provides scientific evidence for the regulation of GLP-1 metabolism by lactobacilli.
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