痛泻要方对醋酸-电刺激大鼠实验性肠易激综合征作用的研究

[目的]探讨痛泻要方对醋酸-电刺激大鼠实验性肠易激综合征（IBS）的作用及其机制。[方法]给予大鼠慢性反复直结肠灌注醋酸造成炎症刺激,炎症恢复后予小量电刺激诱发高敏感性的肠道发生应激反应,模拟人类IBS,观察痛泻要方对刺激期间大鼠排便量、粪便含水量、血浆P物质（SP）和血管活性肠肽（VIP）水平等各项指标的影响。[结果]模型组与正常组比较,大鼠排便量、粪便含水量增加（P〈0.01）,血浆SP和VIP减少（P〈0.05）;痛泻要方高剂量组与模型组比较,大鼠的排便量、粪便含水量减少（P〈0.05）,血浆SP和VIP增加（P〈0.05）。[结论]醋酸-电刺激大鼠模型可有效模拟人类IBS,痛泻要方能够改善该模型的排便加速、粪便含水量增加、血浆SP和VIP水平紊乱等症状。     

肠易激综合征患者胃运动功能的研究

目的 观察肠易激综合征(IBS)患者的胃运动功能并探讨其在IBS发病中的作用.方法 测定30例腹泻型IBS、46例便秘型IBS患者和30例健康人(对照组)胃固体排空功能,行体表胃电图记录胃电节律变化.结果 与腹泻型患者比较,便秘型患者胃排空延迟的发生率高(P<0.05),二者2 h及6 h胃排空率均明显降低(P<0.01);与对照组比较,IBS患者存在明显的胃电节律紊乱.结论 IBS患者存在胃固体排空障碍及胃电节律紊乱,二者间有一定关系;IBS是一种广泛胃肠道运动障碍性疾病.     

Symptom Provocation in Irritable Bowel Syndrome Effects of Differing Doses of Fructose-Sorbitol

The role of fructose and sorbitol, when ingested together, in the aetiology of irritable bowel syndrome (IBS) is controversial. The aims of this study in IBS patients, therefore, were to compare differences in symptom provocation with various doses of fructose-sorbitol and to relate differences in the extent of colonic hydrogen production after each dose to such symptom provocation. Two different mixtures of fructose and sorbitol-20 g fructose plus 3.5 g sorbitol ('lower' dose) and 25 g fructose plus 5 g sorbitol (‘higher’ dose)-were administered to 15 patients with IBS and to 24 healthy controls. Breath hydrogen concentrations were determined at 10-min intervals for 3 h after ingestion of each mixture, and the presence and severity of a range of gastrointestinal symptoms were recorded on a standard form before, during, and after the study. Total symptom score in IBS patients, but not controls, was greater (p > 0.05) after the higher than after the lower dose of fructose-sorbitol mixture, and, for the higher dose, symptoms were significantly greater in IBS patients than in controls (p > 0.05). Moreover, the increase in total symptom score between the higher and lower dose mixtures was of a greater magnitude (p = 0.01) in IBS patients than in controls. No significant correlation was observed between the increase in symptom score and the increase in peak hydrogen concentration or the increase in integrated hydrogen response between lower and higher dose mixtures, although these latter increases were at times substantial. We conclude that in patients with IBS who ingest fructose and sorbitol simultaneously, the degree of symptom provocation is related to the amounts present in such a mixture but is not related directly to the extent of colonic hydrogen production.     

感染后肠易激综合征肠道局部免疫-神经-内分泌网络功能的变化

肠易激综合征(IBS)是临床上最常见的功能性胃肠病之一。近年来肠道炎症,特别是急性肠道感染后遗留的肠道黏膜低度炎症在IBS中的作用越来越受到重视,此文就肠道黏膜低度炎症和肠道局部免疫变化、肠道神经-内分泌网络变化在IBS发病中的作用作一综述。     

From clinical uncertainties to precision medicine: the emerging role of the gut barrier and microbiome in small bowel functional diseases

Introduction: Over the last decade, remarkable progress has been made in the understanding of disease pathophysiology. Many new theories expound on the importance of emerging factors such as microbiome influences, genomics/omics, stem cells, innate intestinal immunity or mucosal barrier complexities. This has introduced a further dimension of uncertainty into clinical decision-making, but equally, may shed some light on less well-understood and difficult to manage conditions.

Areas covered: Comprehensive review of the literature on gut barrier and microbiome relevant to small bowel pathology. A PubMed/Medline search from 1990 to April 2017 was undertaken and papers from this range were included.

Expert commentary: The scenario of clinical uncertainty is well-illustrated by functional gastrointestinal disorders (FGIDs). The movement towards achieving a better understanding of FGIDs is expressed in the Rome IV guidelines. Novel diagnostic and therapeutic protocols focused on the GB and SB microbiome can facilitate diagnosis, management and improve our understanding of the underlying pathological mechanisms in FGIDs.     

Daily gastrointestinal symptoms in women with and without a diagnosis of IBS

This study compared daily gastrointestinal symptoms and stool characteristics across two menstrual cycles, and recalled bowel symptoms and psychological distress in women with irritable bowel syndrome (IBS,N=22), IBS nonpatients (IBS-NP,N=22), and controls (N =25). Daily reports of abdominal pain, bloating, intestinal gas, constipation, and diarrhea did not differ significantly between the IBS and IBS-NP groups but both groups reported significantly higher symptoms than the control group. Stool consistencies was significantly looser in the IBS group relative to the control group. Menstrual cycle effects on symptoms were noted in all the groups. There were no significant differences in psychological distress between women with IBS, and IBS-NP, but both groups reported significantly higher global distress than the control group. The lack of difference between the IBS and IBS-NP groups in contrast to the results of others, can be understood in terms of differences in recruitment strategies.This work was supported by the National Institute for Nursing Research, NIH, grant NR01094.     

HLA-A and HLA-B genes are involved in the pathogenesis of IBS

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder. The pathogenesis of IBS has not yet been fully elucidated, and the relationship between human leukocyte antigen (HLA) class I molecules and IBS is not clear. The present case-control study investigated the correlation between HLA-A and HLA-B genes and IBS. Peripheral blood samples were collected from 102 IBS patients and 108 healthy volunteers at Nanning First People’s Hospital. DNA was extracted using a routine procedure, and HLA-A and HLA-B gene polymorphisms were identified by polymerase chain reaction with sequence-specific primers to determine the genotype and distribution frequency of HLA-A and HLA-B in IBS patients and healthy controls. Susceptibility and protective genes for IBS were identified using univariate and multivariate analyses. The frequency of HLA-A11 gene expression in the IBS group was significantly higher than that in the healthy control group, while the frequencies of HLA-A24, 26, and 33 gene expression were significantly higher in the healthy control group than in the IBS group (all P < .05). The frequencies of HLA-B56 and 75 (15) gene expression in the IBS group were significantly higher than those in the healthy control group, while the frequencies of HLA-B46 and 48 gene expression were significantly higher in the healthy control group than in the IBS group (all P < .05). Genes that may be related to the prevalence of IBS were included in the multivariate logistic regression, and the results suggested that the HLA-B75 (15) gene is a susceptibility gene for IBS (P = .031, odds ratio [OR] = 2.625, 95% confidence interval [CI]: 1.093–6.302), while the HLA-A24 (P = .003, OR = 0.308, 95% CI: 0.142–0.666), A26 (P = .009, OR = 0.162, 95% CI: 0.042–0.629), A33 (P = .012, OR = 0.173, 95% CI: 0.044–0.679), and B48 (P = .008, OR = 0.051, 95% CI: 0.006–0.459) genes are protective genes for IBS.     

Rifaximin is associated with modest,transient decreases in multiple taxa in the gut microbiota of patients with diarrhoea-predominant irritable bowel syndrome

Rifaximin, a non-systemic antibiotic, is efficacious for the treatment of diarrhoea-predominant irritable bowel syndrome (IBS-D). Given the emerging association between the gut microbiota and IBS, this study examined potential effects of rifaximin on the gastrointestinal microbial community in patients with IBS-D. TARGET 3 was a randomised, double-blind, placebo-controlled, phase 3 study. Patients with IBS-D initially received open-label rifaximin 550 mg 3 times daily (TID) for 2 weeks. Patients who responded to the initial treatment and then relapsed were randomised to receive 2 repeat courses of rifaximin 550 mg TID or placebo for 2 weeks, with each course separated by 10 weeks. Stool samples were collected at the beginning and end of open-label treatment, at the beginning and end of the first double-blind treatment, and at the end of the study. As a secondary analysis to the TARGET 3 trial, the composition and diversity of the gut microbiota were assessed, from a random subset of patients, using variable 4 hypervariable region 16S ribosomal RNA gene sequencing. Samples from 103 patients were included. After open-label rifaximin treatment for 2 weeks, 7 taxa (e.g. Peptostreptococcaceae, Verrucomicrobiaceae, Enterobacteriaceae) had significantly lower relative abundance at a 10% false discovery rate threshold. The effects of rifaximin were generally short-term, as there was little evidence of significantly different changes in taxa relative abundance at the end of the study (up to 46 weeks) versus baseline. The results suggest that rifaximin has a modest, largely transient effect across a broad range of stool microbes. Future research may determine whether the taxa affected by rifaximin are causally linked to IBS-D.

ClinicalTrials.gov identifier number: NCT01543178.     

A prospective assessment of bowel habit in irritable bowel syndrome in women: defining an alternator

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is subtyped as IBS with diarrhea (IBS-D) or IBS with constipation (IBS-C) based on Rome II guidelines. The remaining group is considered as having mixed IBS (IBS-M). There is no standard definition of an alternator (IBS-A), in which bowel habit changes over time. Our aim was to use Rome II criteria to prospectively assess change in bowel habit for more than 1 year to understand IBS-A. METHODS: Female patients (n=317) with IBS entering a National Institutes of Health treatment trial were studied at baseline with questionnaires and 2-week daily diary cards of pain and stool frequency and consistency. Studies were repeated at the end of treatment (3 months) and at four 3-month intervals for one more year. Algorithms to classify subjects into IBS-D, IBS-C, and IBS-M groups used diary card information and modified Rome II definitions. Changes in bowel habit at 3-month intervals were then assessed using these surrogate diary card measures. RESULTS: At baseline, 36% had IBS-D, 31% IBS-M, and 34% IBS-C. Except for stool frequency, there were no differences between groups. While the proportion of subjects in each subgroup remained the same over the year, most individuals (more than 75%) changed to either of the other 2 subtypes at least once. IBS-M was the least stable (50% changed out by 12 weeks). Patients were more likely to transition between IBS-M and IBS-C than between IBS-D and IBS-M. Notably, only 29% switched between the IBS-D and IBS-C subtypes over the year. CONCLUSIONS: While the proportion of subjects in each of the IBS subtypes stays the same, individuals commonly transition between subtypes, particularly between IBS-M and IBS-C. We recommend that IBS-A be defined as at least one change between IBS-D and IBS-C by Rome II criteria over a 1-year period.     

Reduced interstitial cells of Cajal and increased intraepithelial lymphocytes are associated with development of small intestinal bacterial overgrowth in post-infectious IBS mouse model

Objective: Intestinal dysmotility and immune activation are likely involved in the pathogenesis of small intestinal bacteria overgrowth (SIBO) in irritable bowel syndrome (IBS). We aimed at investigating the role of interstitial cells of Cajal (ICC) and intestinal inflammation in the development of SIBO using a post-infectious IBS (PI-IBS) mouse model.

Materials and methods: NIH mice were randomly infected with Trichinella spiralis. Visceral sensitivity and stool pattern were assessed at 8-weeks post-infection (PI). Intestinal bacteria counts from jejunum and ileum were measured by quantitative real-time PCR to evaluate the presence of SIBO. ICC density, intraepithelial lymphocytes (IELs) counts, and intestinal cytokine levels (IL1-β, IL-6, toll-like receptor-4 (TLR-4), IL-10) in the ileum were examined.

Results: PI-IBS mice demonstrated increased visceral sensitivity compared with the control group. One-third of the PI-IBS mice developed SIBO (SIBO+/PI-IBS) and was more likely to have abnormal stool form compared with SIBO negative PI-IBS (SIBO?/PI-IBS) mice but without difference in visceral sensitivity. SIBO+/PI-IBS mice had decreased ICC density and increased IELs counts in the ileum compared with SIBO?/PI-IBS mice. No difference in inflammatory cytokine expression levels were detected among the groups except for increased TLR-4 in PI-IBS mice compared with the control group.

Conclusions: Development of SIBO in PI-IBS mice was associated with reduced ICC density and increased IELs counts in the ileum. Our findings support the role of intestinal dysmotility and inflammation in the pathogenesis of SIBO in IBS and may provide potential therapeutic targets.     

Original research: National survey evaluating the provision of gastroenterology dietetic services in England

AimsThe aim of the study was to assess the provision of dietetic services for coeliac disease (CD), irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD).MethodsHospitals within all National Health Service trusts in England were approached (n=209). A custom-designed web-based questionnaire was circulated via contact methods of email, post or telephone. Individuals/teams with knowledge of gastrointestinal (GI) dietetic services within their trust were invited to complete.Results76% of trusts (n=158) provided GI dietetic services, with responses received from 78% of these trusts (n=123). The median number of dietitians per 100 000 population was 3.64 (range 0.15–16.60), which differed significantly between regions (p=0.03). The most common individual consultation time for patients with CD, IBS and IBD was 15–30 min (43%, 44% and 54%, respectively). GI dietetic services were delivered both via individual and group counselling, with individual counselling being the more frequent delivery method available (93% individual vs 34% group). A significant proportion of trusts did not deliver any specialist dietetic clinics for CD, IBS and IBD (49% (n=60), 50% (n=61) and 72% (n=88), respectively).ConclusionThere is an inequity of GI dietetic services across England, with regional differences in the level of provision and extent of specialist care. Allocated time for clinics appears to be insufficient compared with time advocated in the literature. Group clinics are becoming a more common method of dietetic service delivery for CD and IBS. National guidance on GI dietetic service delivery is required to ensure equity of dietetic services across England.     

Abnormal Propagation Pattern of Duodenal Pressure Waves in the Irritable Bowel Syndrome (IBS)

The propagation pattern of individual pressure waves in the gastroduodenal area in IBS is unexplored. We performed antroduodenojejunal manometry on 26 patients with IBS—13 with diarrhea predominant IBS (IBS-D) and 13 with constipation predominant IBS (IBS-C)—and 32 healthy controls. Neuropathic-like motor abnormalities were found in 38% of the patients with conventional manometric evaluation. With high-resolution analysis additional abnormalities were observed in the majority of the patients, with increased frequency of retrograde pressure waves postprandially in both IBS subgroups and in phase II in IBS-D. A correlation between subjective gastrointestinal symptoms and the frequency of retrograde pressure waves in phase II in IBS-D was demonstrated. Motility indices and the number of long clusters were also higher in patients compared to controls. To conclude, an abnormal propagation pattern of individual duodenal pressure waves in IBS patients was demonstrated and found to be related to symptom severity in diarrhea-predominant IBS. High-resolution analysis adds information to standard manometry.     

Experiences of the effects of physical activity in persons with irritable bowel syndrome (IBS): a qualitative content analysis

Objective: Increased physical activity has been tested among patients with irritable bowel syndrome (IBS) in a randomized trial which demonstrated improvement in gastrointestinal (GI) symptoms. The patients’ experiences of the effects of physical activity on IBS symptoms are unknown. This knowledge is necessary to enable suitable support from health care professionals. The aim of this study was therefore to explore patients’ experiences of the effects of physical activity.

Materials and methods: Deep interviews were conducted with 15 patients (10 women and 5 men) aged 31–78 years. Their IBS had lasted for 10–57 years. The transcribed interviews were analyzed through a qualitative content analysis.

Results: The analysis of the material revealed three themes; GI symptoms, extra-intestinal symptoms, and quality of life (QOL). In relation to GI symptoms, the patients discussed how physical activity affected these symptoms and how they used physical activity to normalize and control their GI symptoms. Extra-intestinal symptoms were also affected by physical activity, and the patients described how they experienced a general bodily wellbeing as well as improved mood and energy in relation to physical activity. In terms of QOL, the patients discussed their perspectives on physical activity as giving them achievements, being pleasurable, and being strengthening of the self.

Conclusions: Our results emphasize the importance of taking into account the patient’s experiences of the effects of physical activity when coaching patients with IBS to be physically active. Using a person-centred approach incorporating, the patient’s own experiences and resources is the key to successfully promoting physical activity in the clinic.     

ICC density predicts bacterial overgrowth in a rat model of post-infectious IBS

AIM:To investigate the interstitial cells of Cajal(ICC) number using a new rat model.METHODS:Sprague-Dawley rats were assigned to two groups.The first group received gavage with Campylobacter jejuni(C.jejuni) 81-176.The second group was gavaged with placebo.Three months after clearance of Campylobacter from the stool,precise segments of duodenum,jejunum,and ileum were ligated in self-contained loops of bowel that were preserved in anaerobic bags.Deep muscular plexus ICC(DMP-ICC) were quantified by two blind...     

Bile acid malabsorption: An under-investigated differential diagnosis in patients presenting with diarrhea predominant irritable bowel syndrome type symptoms

Abstract

Objective. Bile acid malabsorption (BAM) has been reported as a possible cause of diarrhea predominant irritable bowel syndrome (D-IBS) type symptoms. We aimed to determine how commonly patients with D-IBS type symptoms had a diagnosis of BAM as demonstrated by a positive SeHCAT (75 Selenium-homocholic acid taurine) test (retention <10% at seven days). Materials and methods. A retrospective analysis was undertaken of patient's records for all patients who underwent a SeHCAT test between 2001 and 2009 in a tertiary hospital (Group A). Concurrently, a cohort of patients with Rome II D-IBS type symptoms was examined to determine the potential utility of SeHCAT test (Group B). Results. In Group A 39.2% (n = 107/273) of patients had a positive SeHCAT result. The median time from first hospital visit to SeHCAT result was 30 weeks. Predictive factors for BAM: terminal ileal Crohn's disease (p < 0.01), terminal ileal resection (p < 0.01), and previous cholecystectomy (p < 0.01). 33.6% of patients who had a positive SeHCAT also had Rome II D-IBS. In Group B the D-IBS control cohort only 1.9% of patients had undergone a SeHCAT scan (p < 0.001 compared to Group A). Conclusion. BAM is common and should be considered earlier when investigating unselected patients with D-IBS type symptoms.     

固本调肠汤治疗腹泻型肠易激综合征疗效观察

[目的]观察中药固本调肠汤治疗脾肾阳虚型腹泻型肠易激综合征(IBS-D)的疗效.[方法]将90例患者随机分为2组,各45例,治疗组予固本调肠汤,对照组予马来酸曲美布汀胶囊治疗.治疗4周,采用临床积分差值法,观察IBS-D的总疗效及主要症状疗效.[结果]治疗后,治疗组改善IBS-D主要症状腹痛、大便次数及性状疗效优于对照组(P＜0.05);改善疾病的严重度疗效优于对照组(P＜0.05).[结论]以温肾健脾法为组方原则的固本凋肠汤对IBS-D的临床疗效明显优于马来酸曲美布汀.