Irritable bowel syndrome (IBS) is a functional bowel disorder featured by recurrent abdominal pain and changes in defecation habits, seriously impairing the quality of life of patients. The effects of widely used treatment targeting gut dysbiosis in IBS patients are reported to be various. There are no unified conclusions on the association between gut microbiota status and treatment, and post-treatment changes in gut microbiota. So there is a lack of high-quality evidence for microbiota-targeted treatment in IBS.

To analyze the effect of common microbiota-targeted therapies on gut microbiota in patients with IBS.

The databases of Web of Science Core Collection, PubMed, Embase and Cochrane Library were searched from inception to May 20, 2022 for studies about the changes of gut microbiota after treatment with one kind of probiotics, prebiotics, antibiotics and fecal microbiota transplantation (FMT) . The data including first author, country, publication year, diagnostic criteria, IBS subtype, sample size, drug type, route and location of FMT, dose and course of treatment, sample and method of microbiota detection, and results of microbiota detection were extracted, and the research results were summarized and reported.

In total, 3 044 studies were retrieved, and 41 of them were included according to inclusion and exclusion criteria, including 11 on probiotics, 8 on prebiotics, 5 on antibiotics and 17 on FMT. Randomized controlled trials accounted for the largest percentage of the total. The most frequently used diagnostic criteria was Rome Ⅲ criteria. IBS with diarrhoea was the most prevalent IBS subtype. The 16S rRNA amplicon sequencing was the mostly used technique for microbiome analysis. Lactobacillus was the most common bacterial strains used as probiotics, which can maintain its activity in the feces of IBS patients. Prebiotics could facilitate the colonization of probiotics (mainly Bifidobacteria) in feces and colonic mucosa. Rifaximin, an antibiotic acting locally in the intestine, could reduce the species richness of the microbiota, but had no significant effect on the microbial structure. After FMT, the microbial structure of IBS patients tended to be similar to that of donors, with increased probiotics and reduced abundance of pathogenic bacteria.

Treatment targeting microbiota, including probiotics, prebiotics, nonabsorbable antibiotics and FMT, is helpful for the improvement and reconstruction of intestinal microenviroment in IBS patients. More accurate post-treatment changes of microbiota will be obtained by unifying the diagnostic criteria, using more advanced detection technique, and controlling the follow-up time accurately, thereby providing a basis for clinical development of accurate microbiota-targeted intervention strategies.

肠易激综合征（IBS）是一种以反复发作的腹痛并伴有排便习惯改变为特征的功能性肠病，严重影响患者的生活质量。针对IBS患者肠道菌群紊乱的治疗手段已广泛应用于临床，但效果不一，患者肠道菌群状态如何影响治疗效果、治疗后肠道菌群的变化尚缺乏统一结论，难以为靶向菌群治疗IBS提供确切参考意见。

分析常用靶向菌群治疗方法对IBS患者肠道菌群的影响。

检索自建库至2022-5-20 Web of Science核心合集、PubMed、Embase、Cochrane Library数据库，筛选报告了使用单一种类的益生菌、益生元、抗生素与粪菌移植治疗后IBS患者肠道菌群变化的文献，提取第一作者、国家、发表时间、诊断标准、IBS亚型、样本量、药物种类、粪菌移植途径与部位、剂量与疗程、菌群检测标本与方法、菌群检测结果等信息，汇总并报告研究结果。

共检索出3 044篇文献，依据纳入与排除标准共筛选纳入41篇文献，其中益生菌研究11篇、益生元研究8篇、抗生素研究5篇、粪菌移植研究17篇。随机对照试验、RomeⅢ、腹泻型IBS、16S rRNA扩增子测序分别为采用最多的试验类型、诊断标准、IBS亚型及菌群检测方法。乳杆菌属是使用最多的益生菌种类，可在IBS患者粪便中保持活性。益生元可促进粪便与结肠黏膜中益生菌（主要是双歧杆菌属）的定殖。肠道局部作用的抗生素利福昔明可降低菌群物种丰富度，但对菌群结构无显著影响。粪菌移植后IBS患者的菌群结构趋同于供者，并可增加患者肠道益生菌、降低有害菌的丰度。

益生菌、益生元、非吸收性抗生素、粪菌移植等靶向菌群的治疗手段有助于IBS患者肠道菌群的改善与重建，今后可通过统一诊断标准、使用更先进的菌群检测技术、精准把控随访时间，进一步得出更为精确的治疗后菌群变化，为临床制订精准的靶向菌群干预策略提供依据。