活性乳酸菌改善酒精性肝损伤的效果及机制研究

Long-term excessive drinking can lead to severe liver injury. Intestinal endotoxemia and inflammatory response caused by imbalance of intestinal flora play a critical role in the alcoholic liver injury. Active lactobacteria can regulate intestinal flora through antagonism of colonization, inhibiting pathogens and nutrition effect. There are many researches from animal experiments and cytological study in vitro relating to the effect of active lactobacteria on improving alcoholic liver injury However, the report about population-based study of the supplement of active lactobacteria on improving alcoholic liver injury through regulating intestinal flora by using modern molecular biology techniques was rare. Therefore, this study plans to utilize the double-blind clinical randomized controlled trials for comprehensively evaluating the effect of supplement of active lactobacteria in patients with alcoholic liver injury There were totally 180 patients diagnosed with alcoholic liver injury enrolled in this study. All patients were randomly divided into three groups, involving placebo control group, low-dose active lactobacillus casei group (viable count: 10 billion/day) and high-dose active lactobacillus casei group (viable count: 20 billion/day). The whole experiment lasted for 2 months. PCR-DGGE fingerprint analysis and 454 pyrosequencing were used to analyzing the changes of intestinal flora before and after, and to evaluating the effect and mechanism of the supplement of active lactobacteria on improving endoxemia and inflammatory response in patients with alcoholic liver injury. The results would guide patients with alcoholic liver injury to properly supply active lactobacteria and provide new evidence and strategy on interventional treatment of alcoholic liver injury.

长期大量饮酒可导致肝脏损伤。由肠道菌群失调引发的肠源性内毒素血症及其介导的炎性反应与肝损伤密切相关。活性乳酸菌制剂可通过定植拮抗、抑制病原菌及营养作用，发挥对肠道菌群调节作用。活性乳酸菌改善酒精性肝损伤效果已有研究，但大多来自动物和体外细胞学实验，而利用多种现代分子生物学技术，开展人群活性乳酸菌补充，探讨其调节肠道菌群改善酒精性肝损伤作用机制研究鲜有报道。本课题拟采用随机双盲对照干预试验，选择180名酒精肝损伤（病）患者，随机分为三组，即安慰剂对照组、100亿活性干酪乳杆菌/d和200亿活性干酪乳杆菌/d干预组，补充时间为2个月。采用DGGE 指纹图谱分析、454高通量测序等技术分析补充前后肠道菌群的变化，对比分析活性乳酸菌补充改善酒精性肝损伤患者内毒素血症、炎性反应的效果及机制。该研究成果可指导酒精性肝损伤人群合理补充活性乳酸菌，并为酒精性肝损伤干预治疗提供新的依据和策略。

本研究通过对酒精性肝损伤人群进行营养风险筛查证实，ALD患者普遍存在营养不良，是营养不良高发人群。ALD患者膳食营养状况不容乐观，亦常出现蛋白质、维生素、矿物质等营养素缺乏。人群干预试验证实，活性乳酸菌对酒精性肝损伤患者具有明显的保护作用。干酪乳杆菌补充不仅可以不同程度的抑制总胆红素、间接胆红素、ALT、AST和GGT水平的升高，也可在一定程度上抑制血清中TG和TC水平的升高，并显著抑制血清中LDLC水平的升高，同时，干酪乳杆菌补充也可以在一定程度上抑制促炎因子TNF-α、IL-6及IL-1β水平升高，且高剂量补充还显著提高了抗炎因子IL-10分泌水平。另外，活性乳酸菌对酒精所致的肠道屏障损伤及肠道菌群紊乱也具有一定的保护作用。干酪乳杆菌对酒精性肝损伤保护作用机制可能与其调节脂质代谢、调节炎症反应、改善肠道屏障损伤、调节肠道菌群失调有关。这些为丰富酒精肝治疗方法和指导人群合理利用益生菌制剂，增进健康提供科学依据，具有良好的应用前景。