Background Nonalcoholic fatty liver disease (NAFLD) is the highest incidence of chronic liver disease worldwide, seriously endangering human health, and its pathogenesis is still unclear. In the recent years, increasing evidence has shown that intestinal flora plays an important role in the occurrence and development of NAFLD. Synbiotics can alter gut microbiota and may be a treatment option for NAFLD in the future. Objectives To systematically investigate the therapeutic effect of synbiotic supplementation on NAFLD patients. Design A systematic review and meta-analysis were conducted. Data sources and methods We conducted a search on four databases (PubMed, Embase, Cochrane Library, and Web of Science) to identify relevant studies. Eligible studies were then screened, and data from the included studies were extracted, combined, and analyzed. Result This study analyzed 10 randomized controlled trials involving 634 patients with NAFLD. The results showed that synbiotic supplementation could significantly reduce the level of alanine aminotransferase (mean difference (MD) = -8.80; (95% CI [-13.06, -4.53]), p < 0.0001), aspartate aminotransferase (MD = -9.48; 95% CI [-12.54, -6.43], p < 0.0001), and γ-glutamyl transferase (MD = -12.55; 95% CI [-19.40, -5.69], p = 0.0003) in NAFLD patients. In the field of metabolism, synbiotic supplementation could significantly reduce the level of total cholesterol (MD = -11.93; 95% CI [-20.43, -3.42], p = 0.006) and low-density lipoprotein cholesterol (MD = -16.2; 95% CI [-19.79, -12.60], p < 0.0001) and increase the level of high-density lipoprotein cholesterol (MD = 1.56; 95% CI [0.43, 2.68], p = 0.007) in NAFLD patients. In addition, synbiotic supplementation could significantly reduce liver stiffness measurement indicator (MD = -1.09; 95% CI [-1.87, -0.30], p = 0.006) and controlled attenuation parameter indicator (MD = -37.04; 95% CI [-56.78, -17.30], p = 0.0002) in NAFLD patients. Conclusion Based on the current evidence, synbiotic supplementation can improve liver function, adjust lipid metabolism, and reduce the degree of liver fibrosis in patients with NAFLD, but these effects need to be confirmed by further studies.

中文翻译：

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合生元对 NAFLD 患者的作用：系统评价和荟萃分析。

研究背景非酒精性脂肪性肝病（NAFLD）是全球发病率最高的慢性肝病，严重危害人类健康，其发病机制尚不清楚。近年来，越来越多的证据表明肠道菌群在NAFLD的发生、发展中发挥着重要作用。合生元可以改变肠道微生物群，并且可能成为未来 NAFLD 的治疗选择。目的 系统研究合生元补充剂对 NAFLD 患者的治疗效果。设计 进行了系统评价和荟萃分析。数据来源和方法 我们对四个数据库（PubMed、Embase、Cochrane Library 和 Web of Science）进行了检索，以确定相关研究。然后筛选符合条件的研究，并提取、合并和分析纳入研究的数据。结果本研究分析了 10 项随机对照试验，涉及 634 名 NAFLD 患者。结果显示，补充合生元可显着降低丙氨酸氨基转移酶（平均差（MD）= -8.80；（95% CI [-13.06，-4.53]），p < 0.0001）、天冬氨酸氨基转移酶（MD = -9.48；95% CI [-13.06，-4.53]）水平。 NAFLD 患者中 95% CI [-12.54, -6.43], p < 0.0001) 和 γ-谷氨酰转移酶 (MD = -12.55; 95% CI [-19.40, -5.69], p = 0.0003)。在代谢领域，补充合生元可显着降低总胆固醇（MD = -11.93；95% CI [-20.43，-3.42]，p = 0.006）和低密度脂蛋白胆固醇（MD = -16.2；95）水平NAFLD 患者的 % CI [-19.79, -12.60], p < 0.0001) 并增加高密度脂蛋白胆固醇水平 (MD = 1.56; 95% CI [0.43, 2.68], p = 0.007)。此外，补充合生元可显着降低肝脏硬度测量指标（MD = -1.09；95% CI [-1.87，-0.30]，p = 0.006）和受控衰减参数指标（MD = -37.04；95% CI [-56.78） ，-17.30]，p = 0.0002）在 NAFLD 患者中。结论 根据现有证据，补充合生元可以改善NAFLD患者的肝功能、调整脂质代谢、减轻肝纤维化程度，但这些作用有待进一步研究证实。