The gut-brain axis and depressive symptoms: a systematic review of randomized clinical trials with probiotics

ABSTRACT Objective: Currently, the gut-brain axis has been highlighted as an important aspect for understanding behavior and mental illnesses. The present study aimed to analyze the effects of probiotic consumption on depressive symptoms and major depression. Methods: A review of randomized, double or triple blind and placebo-controlled trials, published between 2010 and 2020, was performed in PubMed, ScienceDirect and Google Scholar. Results: Eight articles were selected to compose the sample. Findings between studies are controversial, and indicate that a causal relation between probiotic consumption and relieve of depressive symptoms is not yet established. Conclusion: More randomized, double or triple blind, placebo-controlled trials are necessary to consistently verify the causal relation between probiotic consumption and relieve of depressive symptoms.

摘要
目的：目前，肠-脑轴（gut-brain axis）已成为理解行为与精神疾病的重要研究视角。本研究旨在分析益生菌摄入对抑郁症状及重度抑郁症的影响。
方法：本研究对2010年至2020年间发表于PubMed、ScienceDirect及Google Scholar的随机、双盲或三盲安慰剂对照试验进行了综述。
结果：最终共纳入8篇文献组成研究样本。各研究结果存在争议，表明益生菌摄入与抑郁症状缓解之间的因果关系尚未明确确立。
结论：仍需开展更多随机、双盲或三盲安慰剂对照试验，以持续验证益生菌摄入与抑郁症状缓解之间的因果关系。