乳果糖联合微生态制剂对便秘型肠易激综合征的疗效观察

[目的]探讨乳果糖口服液联合微生态制剂(美常安)治疗便秘型肠易激综合征(IBS-C)的临床疗效。[方法]IBS-C患者231例,随机分为联合治疗组(71例)、乳果糖组(84例)和莫沙必利组(76例),疗程均为8周。记录及评价3组患者治疗前后的排便次数、大便性状及便秘程度。[结果]治疗后,排便次数及大便Bristol评分:3组均较治疗前明显提高,且治疗前后3组之间两两相比较差异无统计学意义。便秘程度的AGACHAN得分:治疗前3组之间比较差异无统计学意义;治疗后,3组均较治疗前明显降低,且联合治疗组明显低于乳果糖组、莫沙必利组,差异有统计学意义(P0.05),而乳果糖组与莫沙必利组治疗后评分差异无统计学意义(P0.05)。[结论]乳果糖联合益生菌可明显改善IBS-C患者便秘程度,但在改善大便性状及大便次数方面与单用乳果糖、莫沙必利的疗效无差别。     

肠康方对肠易激综合征内脏高敏感模型大鼠的作用

[目的]探讨肠康方对肠易激综合征(IBS)内脏高敏感模型大鼠的作用.[方法]制备肠易激综合征内脏高敏感模型,将72只Sprague-Dawley大鼠随机分为6组,即模型组,空白对照组,阳性药物对照组,肠康方高、中、低剂量组.在造模第60天开始灌胃给药或0.9％氯化钠溶液共10d,干预后通过腹肌回缩反射(AWR)半定量评分测定大鼠内脏敏感性.[结果]不同压力下模型组AWR评分显著高于空白对照组,肠康方高、中、低剂量组治疗后AWR评分均显著低于模型组(P＜0.05或P＜0.01).[结论]肠康方可通过改善内脏高敏感治疗IBS.     

Gender-related differences in visceral perception in health and irritable bowel syndrome

BACKGROUND: Irritable bowel syndrome (IBS) is more common in female subjects, and IBS patients generally exhibit reduced pain thresholds to rectal distension. The aim of the present paper was to determine gender-related differences in rectal perception in both healthy controls and IBS patients. METHODS: Fifty-nine IBS patients (age 20-65 years; mean, 39.2 years; 31 women, 28 men) with symptoms that fulfilled Rome-II criteria and 21 healthy controls (age 25-58 years; mean, 37.8 years; 11 women, 10 men) were recruited. Participants completed a questionnaire regarding bowel symptoms and psychological distress, and maximal tolerable pressures were evaluated via barostat tests. RESULTS: Although healthy women appear to have lower perception thresholds than men, significant gender differences in pain sensitivity were not detected (P > 0.05). In addition, female patients with IBS also exhibited no enhanced colorectal perception, as compared with male IBS patients (P > 0.05). CONCLUSIONS: No gender differences in visceral perception were determined to exist between the healthy controls and the IBS patients. Therefore, the increased prevalence of IBS in women may be related to another set of pathophysiological factors, and not to gender-related differences in visceroperception.     

Evidence for autonomic dysregulation in the irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by chronic abdominal pain and visceral hypersensitivity. In this study, resting blood pressure and heart rate were recorded in 20 IBS patients and 23 controls. We assessed pain intensity and unpleasantness to visceral and cutaneous stimuli using rectal distension and immersion of the foot in hot water. Mean resting heart rate was higher in IBS patients compared to controls. IBS patients rated pain intensity and unpleasantness to visceral and cutaneous stimuli significantly higher than controls. In IBS patients, blood pressure was significantly inversely associated with visceral pain and only weakly and positively associated with cutaneous pain; there were no relationships in controls. Sex and anxiety did not explain these relationships. In conclusion, we found evidence suggestive of central autonomic dysregulation in IBS patients.     

Impaired transit and tolerance of intestinal gas in the irritable bowel syndrome

BACKGROUND: Patients with irritable bowel syndrome (IBS) frequently complain of excessive gas but their fasting volume of intestinal gas is apparently normal. We hypothesised that the pathophysiological mechanism involved may be impairment of intestinal gas transit. AIM: To investigate intestinal gas transit and tolerance in IBS patients compared with healthy subjects. METHODS: A gas mixture (N(2), O(2), and CO(2) in venous proportions) was infused into the jejunum of 20 patients with IBS and 20 healthy controls at 12 ml/min for four hours. Gas evacuation, initially flatus from the anus (two hours) and then intrarectally (two hours), was continuously recorded. Symptom perception (0-6 scale) and abdominal distension were measured at 10 minute intervals. RESULTS: After two hours of external gas (flatus) collection, 18 of 20 IBS patients had developed gas retention (>400 ml), increased gastrointestinal symptoms (score >3), or abdominal distension (>3 mm girth increment) compared with only four of 20 control subjects. During intrarectal gas collection, 13 of 17 patients still exhibited abnormal responses. CONCLUSION: A large proportion of patients with IBS can be shown to have impaired transit and tolerance of intestinal gas loads. This anomaly may represent a possible mechanism of IBS symptoms, specifically pain and bloating.     

Colonoscopy as an adjunctive method for the diagnosis of irritable bowel syndrome: Focus on pain perception

Background and Aim: Visceral hypersensitivity is an important component of the pathophysiology of irritable bowel syndrome (IBS). In the present study, we investigated differences in pain perception during colonoscopy between IBS patients and non‐IBS patients. We further assessed the sensitivity, specificity, and predictive values of pain scores to diagnose IBS. Methods: Patients who underwent colonoscopy for the evaluation of gastrointestinal symptoms or for screening purposes were included. All patients completed Rome III criteria questionnaires and reported pain scores on 0–100‐mm visual analog scales after colonoscopy. The patients were divided into three groups: (i) IBS; (ii) other functional gastrointestinal disorders (FGID), including functional bloating, functional diarrhea, and functional constipation; and (iii) healthy controls. Results: A total of 217 patients were included. The pain scores (median, interquartile range) of IBS patients (52, 34–71) were higher than those of the healthy controls (22, 12–35) or other FGID patients (18, 10–29) (P < 0.001). Upper gastrointestinal symptoms were observed more often in the IBS group than in the non‐IBS group (83.2% vs 34.5%, P < 0.001). At the pain score level of 31, the sensitivity, specificity, positive predictive value, and negative predictive value for IBS diagnosis were 86.1%, 75.9%, 75.7%, and 86.3%, respectively. Conclusions: The degree of pain perception during colonoscopy was higher in IBS patients than in non‐IBS patients. We concluded that colonoscopy can be useful in identifying IBS patients, with the additional benefit of excluding organic disorders of the lower gastrointestinal tract.     

Rifaximin for the treatment of diarrhea-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic, functional bowel disorder characterized by abdominal pain or discomfort and altered bowel habit. The pathophysiology is unclear, but may include altered gut motility, visceral hypersensitivity, abnormal central pain processing, chronic low-grade intestinal inflammation, or disturbances in the gut microbiome. These etiological mechanisms, alongside environmental factors such as stress and anxiety, vary between individuals and represent potential targets for treatment. Rifaximin is a poorly absorbed oral antibiotic proposed to act on the gut microenvironment, used in the treatment of travelers’ diarrhea and hepatic encephalopathy. Clinical trials suggest the drug can reduce global IBS symptoms and improve bloating, abdominal pain, and stool consistency in some patients with non-constipated IBS, leading to Food and Drug Administration approval in the United States. This article considers the pharmacology of rifaximin, the evidence for its use in IBS, and the safety and tolerability of the drug.     

Repetitive rectal painful distention induces rectal hypersensitivity in patients with irritable bowel syndrome

Background A reduced rectal perceptual threshold has been reported in patients with irritable bowel syndrome (IBS), but this phenomenon may be induced by a comorbid psychological state. We evaluated the rectal pain threshold at baseline and after conditioning (repetitive rectal painful distention: RRD) in patients with IBS or functional abdominal pain syndrome (FAPS), which is an abdominal pain disorder, and in healthy controls, and determined whether rectal hypersensitivity is a reliable marker for IBS. Methods The rectal sensory threshold was assessed by a barostat. First, a ramp distention of 40 ml/min was induced, and the threshold of pain and the maximum tolerable pressure (mmHg) were measured. Next, RRD (phasic distentions of 60-s duration separated by 30-s intervals) was given with a tracking method until the subjects had complained of pain six times. Finally, ramp distention was induced again, and the same parameters were measured. The normal value was defined by calculating the 95% confidence intervals of controls. Results Five or six of the seven IBS patients showed a reduced rectal pain threshold or maximum tolerable pressure, respectively, at baseline. In all patients with IBS, both thresholds were reduced after RRD load, but they were reduced in none of the patients with FAPS. RRD significantly reduced both thresholds in the IBS group (P < 0.05), but it had no effect in the control or FAPS groups. Conclusions Rectal hypersensitivity induced by RRD may be a reliable marker for IBS. Conditioning-induced visceral hypersensitivity may play a pathophysiologic role in IBS.     

The microbiome of the oral mucosa in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a poorly understood disorder characterized by persistent symptoms, including visceral pain. Studies have demonstrated oral microbiome differences in inflammatory bowel diseases suggesting the potential of the oral microbiome in the study of non-oral conditions.

In this exploratory study we examine whether differences exist in the oral microbiome of IBS participants and healthy controls, and whether the oral microbiome relates to symptom severity.

The oral buccal mucosal microbiome of 38 participants was characterized using PhyloChip microarrays. The severity of visceral pain was assessed by orally administering a gastrointestinal test solution. Participants self-reported their induced visceral pain. Pain severity was highest in IBS participants (P = 0.0002), particularly IBS-overweight participants (P = 0.02), and was robustly correlated to the abundance of 60 OTUs, 4 genera, 5 families and 4 orders of bacteria (r² > 0.4, P < 0.001). IBS-overweight participants showed decreased richness in the phylum Bacteroidetes (P = 0.007) and the genus Bacillus (P = 0.008). Analysis of β-diversity found significant separation of the IBS-overweight group (P < 0.05). Our oral microbial results are concordant with described fecal and colonic microbiome-IBS and -weight associations. Having IBS and being overweight, rather than IBS-subtypes, was the most important factor in describing the severity of visceral pain and variation in the microbiome. Pain severity was strongly correlated to the abundance of many taxa, suggesting the potential of the oral microbiome in diagnosis and patient phenotyping. The oral microbiome has potential as a source of microbial information in IBS.     

Bugs and irritable bowel syndrome: The good,the bad and the ugly

Recently, there has been strong interest in the therapeutic potential of probiotics for irritable bowel syndrome (IBS). At the same time, there is a rapidly growing body of evidence to support an etiological role for gastrointestinal infection and the associated immune activation in the development of post‐infectious IBS. In a more controversial area, small intestinal bacterial overgrowth has been associated with a subset of patients with IBS; the issue of whether it is appropriate to treat a subset of IBS patients with antibiotics and probiotics is currently a matter for debate. Thus, it appears that the gastrointestinal microbial flora may exert beneficial effects for symptoms of IBS under some circumstances, while in other situations gut microbes could give rise to symptoms of IBS. How do we make sense of the apparently diverse roles that ‘bugs’ may play in IBS? To address this question, we have conducted an in‐depth review, attempting where possible to draw lessons from Asian studies.     

肠易激综合征发病机制研究进展

肠易激综合征（irritable bowel syndrome,IBS）是常见的功能性肠病,以腹痛伴有大便性状和排便习惯改变为主 要表现。IBS 发病机制复杂,包括了增加IBS易感性的因素及与症状发作相关的因素,多种因素相互作用导致了相应 的病理生理变化,从而产生IBS症状,文章就已有的研究结果对IBS的发病机制进行总结。     

益生菌对肠易激综合征和炎症性肠病的作用

由于胃肠道微生物参与炎症性肠病（inflammatory bowel disease,IBD）的病理过程,而且最近研究表明微生物可能在肠易激综合征（irritable bowel syndrome,IBS）中扮演重要作用.本文重点关注益生菌在这两种疾病中的作用机制和疗效.胃肠道微生物的组成受多种因素调节,包括年龄、饮食和疾病状态.益生菌可能通过影响宿主的微生物菌群和提高黏膜的免疫调节作用发挥疗效.益生菌的口服耐受性较好.许多短期研究表明益生菌在IBS中有效,尽管只是在部分的特殊菌株和某些特定症状中有效.在IBD中,许多临床试验表明大量的益生菌在结肠袋炎和溃疡性结肠炎中有效,而对克罗恩病无明显疗效.显然,益生菌在IBS和IBD的治疗中能起到巨大的作用,但是,这些只是针对特殊的菌株.将来迫切需要进行高质量的临床研究和实验观察益菌对IBD和IBS的疗效.     

Gut microbiota and irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that poses a significant health concern. Although its etiology remains unknown, there is growing evidence that gut dysbiosis is involved in the development and exacerbation of IBS. Previous studies have reported altered microbial diversity, abundance, and composition in IBS patients when compared to controls. However, whether dysbiosis or aberrant changes in the intestinal microbiota can be used as a hallmark of IBS remains inconclusive. We reviewed the literatures on changes in and roles of intestinal microbiota in relation to IBS and discussed various gut microbiota manipulation strategies. Gut microbiota may affect IBS development by regulating the mucosal immune system, brain–gut–microbiome interaction, and intestinal barrier function. The advent of high-throughput multi-omics provides important insights into the pathogenesis of IBS and promotes the development of individualized treatment for IBS. Despite advances in currently available microbiota-directed therapies, large-scale, well-organized, and long-term randomized controlled trials are highly warranted to assess their clinical effects. Overall, gut microbiota alterations play a critical role in the pathophysiology of IBS, and modulation of microbiota has a significant therapeutic potential that requires to be further verified.     

Bacteria,genetics and irritable bowel syndrome

Evaluation of: Villani AC, Lemire M, Thabane M et al. Genetic risk factors for post-infectious irritable bowel syndrome following a waterborne outbreak of gastroenteritis. Gastroenterology 138, 1502–1513 (2010).

While the pathogenesis of irritable bowel syndrome (IBS) remains to be fully defined, two clinical observations – the occurrence, de novo, of IBS following bacterial gastroenteritis and the history, commonly obtained from IBS patients, of other instances of the syndrome within their families – have instigated investigations, in IBS, of the potential roles, on the one hand, of the gut microbiota and the host response and, on the other hand, of genetic factors. The study reviewed here relates to both of these factors by studying genetic predisposition to postinfective IBS in a large population of individuals who were exposed to a multimicrobial enteric infection, which resulted in a severe outbreak of gastroenteritis and was followed by the development of IBS in over a third. In this detailed study, the investigators identified a number of genes that were linked significantly to the development of postinfectious-IBS in the Toll-like receptor 9, IL-6 and cadherin 1 regions. These genes play important roles in bacterial recognition, the inflammatory response and epithelial integrity, respectively, and provide considerable support for the hypothesis that links IBS onset to disturbances in the microbiota and the host response.     

Irritable bowel syndrome,the microbiota and the gut-brain axis

Irritable bowel syndrome is a common functional gastrointestinal disorder and it is now evident that irritable bowel syndrome is a multi-factorial complex of changes in microbiota and immunology. The bidirectional neurohumoral integrated communication between the microbiota and the autonomous nervous system is called the gut-brain-axis, which integrates brain and GI functions, such as gut motility, appetite and weight. The gut-brain-axis has a central function in the perpetuation of irritable bowel syndrome and the microbiota plays a critical role. The purpose of this article is to review recent research concerning the epidemiology of irritable bowel syndrome, influence of microbiota, probiota, gut-brain-axis, and possible treatment modalities on irritable bowel syndrome.     

Post-infectious irritable bowel syndrome in patients with Shigella infection

BACKGROUND AND AIMS: Bacterial gastroenteritis has been known as a risk factor of irritable bowel syndrome (IBS). Several risk factors of post-infectious IBS (PI-IBS) have been documented. The aims of this study were to verify the role of bacterial gastroenteritis in the development of IBS and the risk factors for the development of PI-IBS. The clinical course of PI-IBS was also investigated. METHODS: We recruited 143 patients with shigellosis during its outbreak and 113 controls. Both groups were followed up for 12 months. Bowel symptoms were evaluated by use of questionnaires at 3, 6 and 12 months after the initial recruitment. RESULTS: Complete data were obtained from 101 patients (70.6%) and 102 healthy controls (90.3%). At 12 months, 15 patients and six controls had IBS (adjusted OR; 2.9, 95% CI; 1.1-7.9). Of the 15 patients, five had IBS symptoms consistently for 12 months, three did not have IBS symptoms initially and seven had fluctuating bowel symptoms. The duration of diarrhea was an independent risk factor of PI-IBS. CONCLUSIONS: Bacterial gastroenteritis is a risk factor of IBS and the duration of diarrhea as the index of severity of initial illness is an independent risk factor of PI-IBS. The clinical course of PI-IBS is variable over the 1 year of follow-up.