The pathophysiology of functional dyspepsia (FD) remains poorly understood, but alterations of the small intestinal microbiome have been observed. The place of probiotics in treatment is uncertain. We performed a systematic review and meta-analysis of the currently available randomized, controlled trials (RCTs) to evaluate the potential beneficial effects and risks of probiotics in FD. Pubmed, EMBASE, Scopus, Web of Science and the Cochrane Controlled Trials Register were searched (up to May 2019) for RCTs evaluating the effects of probiotic supplementation compared to placebo in adults with FD. Two reviewers independently assessed eligibility, trial quality and extracted information from identified articles. To compare the effects of probiotics with placebo, risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using random effects models. Six trials, including 422 participants were included but only three RCTs could be included in the meta-analysis. Lactobacillus strains showed potential positive effects in terms of improving upper gastrointestinal (GI) symptoms in patients with FD. Probiotic supplementation tended to improve global dyspepsia score (n = 3 RCTs, risk ratio [RR]: 1.35, 95% CI 0.99 to 1.84; P = 0.061) and bacterial composition in the GI tract. Probiotics were well tolerated without any serious adverse events. While the available data suggest that supplementation with probiotics may improve GI symptoms in patients with FD, the evidence is insufficient to draw clear conclusions regarding efficacy. Thus, high-quality RCTs are needed to establish the beneficial effects of probiotic supplementation on FD outcomes.

功能性消化不良（FD）的病理生理学仍知之甚少，但已观察到小肠微生物组的改变。益生菌在治疗中的位置尚不确定。我们对当前可用的随机，对照试验（RCT）进行了系统的回顾和荟萃分析，以评估益生菌在FD中的潜在有益作用和风险。在Pubmed，EMBASE，Scopus，Web of Science和Cochrane对照试验注册簿中进行搜索（截至2019年5月），以评估在FD成年人中益生菌补充剂与安慰剂相比的疗效。两名审稿人独立评估了资格，试验质量并从确定的文章中提取了信息。为了比较益生菌和安慰剂的作用，使用随机效应模型汇总了具有95％置信区间（CI）的风险比（RR）。纳入了包括422名受试者在内的6个试验，但荟萃分析仅可纳入3个RCT。乳酸菌菌株在改善FD患者的上消化道（GI）症状方面显示出潜在的积极作用。补充益生菌有助于改善消化不良的总体评分（n = 3个RCT，风险比[RR]：1.35，95％CI 0.99至1.84； P = 0.061）和胃肠道细菌组成。益生菌耐受性好，没有任何严重的不良事件。尽管现有数据表明补充益生菌可以改善FD患者的胃肠道症状，但证据不足以就功效得出清晰的结论。因此，需要高质量的RCT来确定补充益生菌对FD结果的有益作用。