氢气结合甲烷气呼气试验检测肠易激综合征患者小肠细菌过度生长

目的通过乳果糖氢气结合甲烷气呼气试验检测肠易激综合征(irritable bowel syndrome,IBS)患者小肠细菌过度生长(small intestinal bacterial overgrowth,SIBO)的发生率,判断SIBO与IBS症状的关系,探讨甲烷呼气试验在不产氢气患者的临床应用价值。方法纳入符合罗马Ⅲ诊断标准的IBS患者和年龄、性别匹配的健康人(对照组),进行乳果糖氢气结合甲烷气呼气试验,计算SIBO阳性发生率,对比各时间点呼气氢与甲烷浓度;将IBS患者分为SIBO阳性组和SIBO阴性组,比较其症状评分。结果共纳入70例IBS患者(IBS组,92.86%为腹泻型和混合型)和30名健康人(对照组)。两组SIBO阳性率分别为71.43%和36.67%(P0.05)。两组甲烷呼气试验结果与氢呼气试验结果均呈显著线性相关(IBS组:r=0.999,P=0.000;对照组:r=0.745,P=0.003),仅1例腹泻型IBS患者氢呼气试验阴性而甲烷呼气试验阳性。SIBO阳性(n=50)与SIBO阴性(n=20)IBS患者症状评分比较,差异无统计学意义(P0.05)。结论 IBS患者SIBO阳性率明显高于健康人,提示SIBO与IBS有关,但SIBO并不加重IBS患者的症状;在乳果糖呼气试验中,甲烷气与氢气浓度呈显著线性相关,甲烷气对不产氢气的IBS患者合并SIBO的补充检测作用有限。     

肠易激综合征与小肠细菌过度生长关系的研究

肠易激综合症（irritable bowel syndrome，IBS）是消化系统常见病，发病机制尚不完全清楚，IBS的主要症状是腹胀、腹痛和大便习惯改变，这些与小肠细菌过度生长（small intestinal bacterial overgrowth，SIBO）的表现相似。我们应用氢呼气试验（hydrogen breath test，HBT）检测31例IBS患者，旨在研究SIBO与IBS的关系及应用抗生素根除SIBO能否改善IBS患者胃肠道症状。     

益生菌和肠易激综合征的关系

肠易激综合征(IBS)是最常见的功能性胃肠病之一,其发病机制目前还不明确。近年发现肠道微生物群可能参与了IBS的发生发展,细菌感染可以诱发感染后IBS;有一部分IBS患者存在小肠细菌过度生长(SIBO)或是菌群组成改变;口服肠道不吸收的抗生素能够减轻IBS的症状。因此有人提出用益生菌治疗IBS可能是一个合理的方法。此文就益生菌治疗IBS的相关研究作一综述。     

脑-肠轴在肠易激综合征发病中的作用

肠易激综合征(IBS)的发病可能与肠道动力异常、内脏高敏感、感染、精神心理等有关。脑-肠轴在IBS发病中的作用引起普遍关注,上述的发病因素均可整合到脑-肠互动框架中进行阐述,脑-肠轴成为研究IBS发病机制的切入点。本文从脑-肠轴的概念、作用机制、脑-肠轴功能异常与IBS发病、靶向治疗等方面对脑-肠轴在IBS发病中的作用作一综述。     

Irritable bowel syndrome and small intestinal bacterial overgrowth:Meaningful association or unnecessary hype

Irritable bowel syndrome(IBS)is a common condition characterized by abdominal pain or discomfort,bloating,and altered stool form and passage.Small intestinal bacterial overgrowth(SIBO)is a condition in which there is overgrowth of bacteria in small bowel in excess of 105colony forming units per milliliter on culture of the upper gut aspirate.Frequency of SIBO varied from 4%-78%among patients with IBS and from 1%-40%among controls.Higher frequency in some studies might be due to fallacious criteria[postlactulose breath-hydrogen rise 20 PPM above basal within 90 min(early-peak)].Glucose hydrogen breath test(GHBT)has a low sensitivity to diagnose SIBO.Hence,studies based on GHBT might have under-estimated frequency of SIBO.Therefore,it is important to analyze these studies carefully to evaluate whether the reported association between IBS and SIBO is over or under-projected.This review evaluates studies on association between SIBO and IBS,discordance between different studies,their strength and weakness including methodological issues and evidence on therapeutic manipulation of gut flora on symptoms of IBS.     

肠上皮细胞紧密连接在肠易激综合征发病中的作用

肠易激综合征(IBS)是常见的功能性胃肠病,其病因和发病机制尚未完全明确。近年肠黏膜屏障在IBS发病中的作用备受关注。肠上皮细胞是肠黏膜屏障的重要组成部分,其功能与细胞间紧密连接(TJ)密切相关。研究证实IBS患者肠黏膜TJ结构异常,可能与IBS发病相关。本文就肠上皮细胞TJ在IBS发病中的作用作一综述。     

肠黏膜分泌物调节肠易激综合征发病机制的研究进展

肠易激综合征(IBS)是一种以腹部不适或腹痛伴排便习惯改变为主要特征的功能性胃肠病。IBS的发病机制与胃肠动力学异常,内脏感觉异常、感染、精神心理因素等有关。其病理生理学机制尚不清楚,现认为脑肠轴神经免疫内分泌功能紊乱参与其中。近年来,研究发现肠黏膜的免疫炎性反应、内分泌功能紊乱以及神经营养因子分泌异常参与调节IBS脑肠轴功能紊乱并且导致肠黏膜异常分泌多种物质。此文主要阐述这些异常分泌的肠黏膜分泌物在IBS发病机制中的重要作用,并为IBS治疗提供一个广阔的前景。     

益生菌和肠易激综合征

肠易激综合征(IBS)的发病机制主要与内脏敏感性、肠道动力异常等有关,目前证实某些益生菌可以减轻IBS腹痛、腹胀等症状.此文主要对IBS病理生理机制、益生菌对IBS的可能作用以及在IBS治疗中的应用作一综述.     

肠易激综合征发病机制的研究进展

肠易激综合征(irritable bowel syndrome,IBS)是一种以腹部不适和排便习惯改变为特征的胃肠功能性疾病.IBS的发病机制仍不清楚,传统观点认为基因、心理社会因素、胃肠动力障碍和内脏高敏感性等是引起IBS的关键因素.近年来,人们陆续发现了一些与IBS发病相关的新病理生理学改变依据,如脑肠轴调节失常、肠道感染、肥大细胞的激活并释放活性物质等.本文总结与IBS发病机制相关的一些最新研究进展.     

肠易激综合征发病机制的研究进展

肠易激综合征(IBS)是一种常见的功能性胃肠道疾病,临床表现主要为腹痛、腹胀以及排便习惯改变。目前,IBS的发病机制尚未完全明确。研究认为IBS是多因素共同作用的结果,相关因素包括生活方式、基因多态性、食物过敏、心理因素、脑-肠轴异常以及肠道菌群失调等。本文就IBS发病机制的研究进展作一综述。     

Antibiotics for Irritable Bowel Syndrome: Rationale and Current Evidence

Irritable bowel syndrome (IBS) is the most common gastrointestinal condition effecting adults in developed countries worldwide. Over the last decade, evidence has emerged suggesting that gut bacteria play a role in the pathophysiology of IBS. While difficult to identify using noninvasive means, one of the most common attributable bacterial concepts in IBS is the small intestinal bacterial overgrowth hypothesis (SIBO). In this article, we review the different mechanisms by which gut flora and, specifically, SIBO may contribute to IBS and the evidence supporting the use of various antibiotic therapies in treating IBS.     

The Prevalence of Overgrowth by Aerobic Bacteria in the Small Intestine by Small Bowel Culture: Relationship with Irritable Bowel Syndrome

Objectives  

Many studies have linked irritable bowel syndrome (IBS) with small intestinal bacterial overgrowth (SIBO), although they have done so on a qualitative basis using breath tests even though quantitative cultures are the hallmark of diagnosis. The purpose of this study was to underscore the frequency of SIBO in a large number of Greeks necessitating upper gastrointestinal (GI) tract endoscopy by using quantitative microbiological assessment of the duodenal aspirate.     

肠易激综合征发病机理的研究进展

肠易激综合征的发病机制至今仍不明确，目前比较一致的观点认为IBS是胃肠动力异常、内脏感觉敏感性增高、肠道感染、炎症、心理社会精神因素、神经免疫内分泌及基因遗传等多种发病机制共同参与共同作用的结果，本文就近年来有关IBS发病机制的研究进展作一综述。     

脑源性神经营养因子在肠道高敏感中的研究进展

内脏敏感性增高是肠易激综合征(IBS)重要的病理生理学机制之一。近年研究显示,脑源性神经营养因子(BDNF)过表达与IBS内脏高敏感密切相关。BDNF作为神经营养因子参与了神经元的存活、生长、发育、分化、再生过程。肠道组织中大量表达BDNF及其受体,对肠神经系统(ENS)的形成和功能具有调节作用,提示BDNF可能在肠道高敏感的发生机制中发挥重要作用。本文就BDNF在肠道高敏感中的研究进展作一综述。     

Management of small intestinal bacterial overgrowth

Similar to that of all mammals, the human gastrointestinal tract is colonized by 100 trillion bacteria shortly after birth. Remarkably, in the open-tube arrangement of the intestine, this bacterial population is tightly compartmentalized to the distal gut. Contamination of the small intestine with colonic bacterial flora or small intestinal bacterial overgrowth (SIBO) has been understood previously as a complication of uncommon conditions associated with obvious intestinal stasis. However, SIBO has also been found in 78% to 84% of patients with the common condition of irritable bowel syndrome (IBS). In this paper, the diagnostic and treatment approaches to SIBO are reconsidered within the larger framework of the patient with IBS.     

肠道菌群失调与肠易激综合征的研究进展

肠易激综合征（IBS）的发病机制复杂,可能与内脏感觉过敏、胃肠道动力异常、肠道菌群失调、小肠细菌过度生长、肠道感染、食物不耐受、免疫异常、社会心理因素以及脑一肠轴异常等有关。研究显示,肠道菌群失调可能与IBS症状的产生和持续有关。本文就肠道菌群失调与IBS的研究进展作一综述。     

The lactulose breath test for diagnosing SIBO in IBS patients: another nail in the coffin

The findings of the lactulose breath test in irritable bowel syndrome patients have been used to suggest that most patients have small intestinal bacterial overgrowth (SIBO), and this association has spawned the widespread use of antibiotics in IBS. The study by Bratten and colleagues demonstrates that this test does not discriminate between IBS patients and healthy controls when criteria from recent clinical IBS studies are applied. When the findings from this large study are combined with previous smaller studies, they challenge the hypothesis that SIBO underlies the symptoms of IBS and undermine the current rationale for the use of antibiotics in IBS.     

Irritable bowel syndrome: the role of the intestinal microbiota, pathogenesis and therapeutic targets

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder that predominantly affects women and accounts for up to 40% of the gastroenterology unit outpatient visits. The pathophysiology is complex and multifactorial. In the present review we will focus on the role of intestinal dysbiosis in its pathogenesis and treatment. Post-infectious IBS (PI-IBS) can put light on the mechanisms underlying IBS. Modified commensal gut flora may lead to mucosal inflammation. Several changes such as an increase in mucosal cellularity (enterochromaffin cells, lamina propria T lymphocytes and mast cells), modified pro-inflammatory/anti-inflammatory cytokine balance and disordered neurotransmission have been observed. The normal microbiota is an essential factor in health. A modification of the flora, such as small intestinal bacterial overgrowth (SIBO) is thought to play a pathogenic role in IBS. Changes in the composition of the luminal and mucosal colonic flora have been linked to IBS. It is not clear however, whether these changes are a cause or a consequence of the syndrome. The comprehension of the interaction between the dysbiotic microbiota and the host will probably lead to the development of focused therapies. Based on these assumptions, treatments modulating the microbiota have been investigated. On the one hand several probiotics have shown a reduction in IBS symptoms by an immunomodulatory and analgesic effects. On the other hand antibiotic treatment has proven efficacy in treating IBS with or without associated SIBO. Due to its complex pathophysiology, treating IBS nowadays implies multiple approaches, one of which may be modulation of the intestinal flora.     

Lower frequency of MMC is found in IBS subjects with abnormal lactulose breath test,suggesting bacterial overgrowth

We have recently described an association between irritable bowel syndrome (IBS) and abnormal lactulose breath test, suggesting small intestinal bacterial overgrowth (SIBO). However, the mechanism by which SIBO develops in IBS is unknown. In this case–control study we evaluate the role of small intestinal motility in subjects with IBS and SIBO. Small intestinal motility was studied in consecutive IBS subjects with SIBO on lactulose breath test. After fluoroscopic placement of an eight-channel water-perfused manometry catheter, 4-hr fasting recordings were obtained. Based on this, the number and duration of phase III was compared to 30 control subjects. To test whether there was a relationship between the motility abnormalities seen and the SIBO status of the patient at the time of the motility, subjects with a breath test within 5 days of the antroduodenal manometry were also compared. Sixty-eight subjects with IBS and SIBO were compared to controls. The number of phase III events was 0.7 ± 0.8 in IBS subjects and 2.2 ± 1.0 in controls (P < 0.000001). The duration of phase III was 305 ± 123 sec in IBS subjects and 428 ± 173 in controls (P < 0.001). Subjects whose SIBO was still present at the time of manometry had less frequent phase III events than subjects with eradicated overgrowth (P < 0.05). In conclusion, phase III is reduced in subjects with IBS and SIBO. Eradication of bacterial overgrowth seems to result in some normalization of motility.