INTRODUCTION We conducted a systematic review and meta-analysis to compare the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with irritable bowel syndrome (IBS) and controls. METHODS Electronic databases were searched up to December 2018 for studies reporting SIBO prevalence in patients with IBS. Prevalence rates, odds ratios (ORs), and 95% confidence intervals (CIs) of SIBO in patients with IBS and controls were calculated. RESULTS We included 25 studies with 3,192 patients with IBS and 3,320 controls. SIBO prevalence in patients with IBS was significantly increased compared with controls (OR = 3.7, 95% CI 2.3-6.0). In studies using only healthy controls, the OR for SIBO in patients with IBS was 4.9 (95% CI 2.8-8.6). With breath testing, SIBO prevalence in patients with IBS was 35.5% (95% CI 33.6-37.4) vs 29.7% (95% CI 27.6-31.8) in controls. Culture-based studies yielded a SIBO prevalence of 13.9% (95% CI 11.5-16.4) in patients with IBS and 5.0% (95% CI 3.9-6.2) in controls with a cutoff value of 10 colony-forming units per milliliter vs 33.5% (95% CI 30.1-36.9) in patients with IBS and 8.2% (95% CI 6.8-9.6) in controls with a cutoff value of 10 colony-forming unit per milliliter, respectively. SIBO prevalence diagnosed by lactulose breath test is much greater in both patients with IBS (3.6-fold) and controls (7.6-fold) compared with glucose breath test. Similar difference is seen when lactulose breath test is compared with culture methods. OR for SIBO in patients with IBS-diarrhea compared with IBS-constipation was 1.86 (95% CI 1.83-2.8). Methane-positive breath tests were significantly more prevalent in IBS-constipation compared with IBS-diarrhea (OR = 2.3, 95% CI 1.2-4.2). In patients with IBS, proton pump inhibitor was not associated with SIBO (OR = 0.8, 95% CI 0.5-1.5, P = 0.55). DISCUSSION This systematic review and meta-analysis suggests a link between IBS and SIBO. However, the overall quality of the evidence is low. This is mainly due to substantial "clinical heterogeneity" due to lack of uniform selection criteria for cases and controls and limited sensitivity and specificity of the available diagnostic tests.

中文翻译：

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肠易激综合症中的小肠细菌过度生长：病例对照研究的系统评价和荟萃分析。

简介我们进行了系统的回顾和荟萃分析，以比较肠易激综合征（IBS）和对照组患者小肠细菌过度生长（SIBO）的发生率。方法检索截至2018年12月的电子数据库，以研究报告IBS患者中SIBO患病率的研究。计算了IBS和对照患者的SIBO患病率，优势比（OR）和95％置信区间（CI）。结果我们纳入了25项研究，对3192例IBS患者和3320例对照进行了研究。与对照组相比，IBS患者的SIBO患病率显着增加（OR = 3.7，95％CI 2.3-6.0）。在仅使用健康对照的研究中，IBS患者的SIBO OR值为4.9（95％CI 2.8-8.6）。通过呼气测试，IBS患者的SIBO患病率为35.5％（95％CI 33.6-37.4）vs 29。对照组中有7％（95％CI 27.6-31.8）。基于文化的研究显示，IBS患者的SIBO患病率为13.9％（95％CI 11.5-16.4），对照组为5.0％（95％CI 3.9-6.2），临界值为每毫升10个菌落形成单位对33.5。 IBS患者的平均百分比（95％CI 30.1-36.9）和对照组的临界值分别为10个菌落形成单位/毫升的比例为8.2％（95％CI 6.8-9.6）。与葡萄糖呼气试验相比，IBS患者和乳糜泻患者的乳果糖呼气试验诊断出的SIBO患病率要高得多（3.6倍）和对照（7.6倍）。将乳果糖呼气试验与培养方法进行比较时，观察到相似的差异。与IBS便秘相比，IBS腹泻患者的SIBO的OR为1.86（95％CI 1.83-2.8）。与IBS腹泻相比，IBS便秘中甲烷阳性呼气试验的发生率更高（OR = 2.3，95％CI 1.2-4.2）。在IBS患者中，质子泵抑制剂与SIBO无关（OR = 0.8，95％CI 0.5-1.5，P = 0.55）。讨论这种系统的回顾和荟萃分析表明，IBS和SIBO之间存在联系。但是，证据的整体质量很低。这主要是由于缺乏针对病例和对照的统一选择标准，以及现有诊断测试的敏感性和特异性有限，导致大量的“临床异质性”。证据的整体质量很低。这主要是由于缺乏针对病例和对照的统一选择标准，以及现有诊断测试的敏感性和特异性有限，导致大量的“临床异质性”。证据的整体质量很低。这主要是由于缺乏针对病例和对照的统一选择标准，以及现有诊断测试的敏感性和特异性有限，导致大量的“临床异质性”。