Ability of lactulose breath test results to accurately identify colorectal polyps through the measurement of small intestine bacterial overgrowth

BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.

Progress in Diagnosis and Treatment of Small Intestinal Bacterial Overgrowth

Small intestinal bacterial overgrowth has been found to be associated with a variety of gastrointestinal disorders such as irritable bowel syndrome, inflammatory bowel disease, and, in recent years, diabetes mellitus and systemic sclerosis, among other extraintestinal diseases. Several novel diagnostic tools for small intestinal bacterial overgrowth have emerged in recent years, and several therapeutic approaches have been proposed. Therefore, it has become necessary to find an effective, safe, and simple diagnostic method and a safe treatment modality. This article provides a review of current diagnostic and therapeutic approaches to small intestinal bacterial overgrowth.

Small intestinal bacterial overgrowth syndrome

Human intestinal microbiota create a complex polymi-crobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO).SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastro-intestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacte-riostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insuff iciency, immuno-deficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, f istulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Noninvasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be com-plex, addressing all causes, symptoms and complica-tions, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO.

Association between acute pancreatitis and small intestinal bacterial overgrowth assessed by hydrogen breath test

AIM To elucidate the effects of small intestinal bacterial overgrowth(SIBO) on the severity and complications of acute pancreatitis(AP).METHODS In total,208 patients with AP as defined by the revised Atlanta classification were admitted to Xuanwu Hospital of capital Medical University from 2013 to 2016. All patients were admitted within 72 h of AP onset. The hydrogen breath test was performed 7 d after AP onset to detect hydrogen production and evaluate the development of SIBO. The incidence of SIBO was analyzed in patients with AP of three different severity grades. The association between SIBO and complications of AP was also assessed.RESULTS Of the 27 patients with severe AP(SAP),seven(25.92%) developed SIBO. Of the 86 patients with moderately severe AP(MSAP),22(25.58%) developed SIBO. Of the 95 patients with mild AP(MAP),eight(8.42%) developed SIBO. There were significant differences in the rates of SIBO among patients with AP of different severities. Additionally,more severe APwas associated with higher rates of SIBO positivity(P < 0.05). SIBO in patients with AP mainly occurred within 72 h of the onset of AP. The incidence of organ failure was significantly higher in patients with SIBO than in those without(P < 0.05).CONCLUSION SIBO occurs more frequently in patients with MSAP or SAP than in those with MAP,usually ≤ 72 h after AP onset. Additionally,SIBO is associated with organ failure.

Breath test for differential diagnosis between small intestinal bacterial overgrowth and irritable bowel disease:An observation on non-absorbable antibiotics

AIM： To estimate the prevalence of small intestine bacterial overgrowth （SIBO） among patients with an earlier diagnosis of irritable bowel disease （IBS） in our geographical area, and to collect information on the use of locally acting non-absorbable antibiotics in the management of SIBO. METHODS： A non-interventional study was conducted in 73 consecutive patients with a symptom-based diagnosis.. RESULTS： When the patients underwent a ＂breath test＂, 33 （45.2%） showed the presence of a SIBO. Arcer treatment with rifaximin 1200 mg/d for seven days in 32 patients, 19 （59.4%） showed a negative ＂breath test＂ one week later as well as a significant reduction of symptoms, thus confirming the relationship between SIBO and many of the symptoms claimed by patients. In the other 13 patients, ＂breath test＂ remained positive, and a further cycle of treatment with ciprofloxacin 500 mg/d was given for 7 additional days, resulting in a negative ＂breath test＂ in one patient only. CONCLUSION： （1） about half of the patients with a symptomatic diagnosis of IBS have actually SIBO, which is responsible for most of the symptoms attributed to IBS; （2） only a ＂breath test＂ with lactulose （or with glucose in subjects with an intolerance to lactose） can provide a differential diagnosis between IBS and SIBO, with almost identical symptoms; and （3） the use of non-absorbable antibiotics may be useful to reduce the degree of SIBO and related symptoms; it must be accompanied, however, by the correction of the wrong alimentary habits underlying SIBO.

Predisposing factors for positive D-Xylose breath test for evaluation of small intestinal bacterial overgrowth:A retrospective study of 932 patients

AIM: To investigate, in the largest cohort to date, patient characteristics and associated risk factors for developing small intestinal bacterial overgrowth(SIBO) using the D-Xylose breath test(XBT).METHODS: We performed a retrospective crosssectional study to analyze patient characteristics who underwent the XBT for evaluation of SIBO. Diagnostic testing with the XBT was performed based on a clinical suspicion for SIBO in patients with symptoms of bloating, abdominal pain, abdominal distension, weight loss, diarrhea, and/or constipation. Consecutive electronicmedical records of 932 patients who completed the XBT at the University of Florida between 2005 and 2009 were reviewed. A two-way Analysis of Variance(ANOVA) was used to test for several associations including age, gender, and body mass index(BMI) with a +XBT. A two-way ANOVA was also performed to control for the differences and interaction with age and between genders. A similar analysis was repeated for BMI. Associations between medical conditions and prior surgical histories were conducted using the Mantel-Haenszel method for 2 by 2 contingency tables, stratified for gender. Reported odds ratio estimates reflect the odds of the prevalence of a condition within the +XBT group to that of the-XBT group. P values of less than 0.05(two-sided) were considered statistically significant.RESULTS: In the 932 consecutive eligible subjects studied, 513 had a positive XBT. A positive association was found between female gender and a positive XBT(P = 0.0025), and females with a positive test were, on average, greater than 5 years older than those with a negative test(P = 0.024). The mean BMI of positive XBT subjects was normal(24.5) and significantly lower than the subjects with a negative XBT(29.5)(P = 0.0050). A positive XBT was associated with gastroesophageal reflux disease(GERD)(OR = 1.35; 95%CI: 1.02-1.80, P = 0.04), peptic ulcer disease(PUD)(OR = 2.61; 95%CI: 1.48-4.59, P < 0.01), gastroparesis(GP)(OR = 2.04; 95%CI: 1.21-3.41, P < 0.01) and steroid use(OR = 1.35; 95%CI: 1.02-1.80, P = 0.01). Irritable bowel syndrome, independent protonpump inhibitor(PPI) usage, or previous abdominal surgery was not significantly associated with a positive XBT. No single subdivision by gender or PPI use was associated with a significant difference in the odds ratios between any of the subsets. CONCLUSION: Female gender, lower BMI, steroid use, PUD, GERD(independent of PPI use), and GP were more prevalent in patients with SIBO, determined by a positive XBT. Increasing age was associated with SIBO in females, but not in males.

Pilot Study on Gas Patterns of Irritable Bowel Syndrome and Small Intestinal Bacterial Overgrowth Following Ingestion of Lactulose

Background & Aims: Fermentation site and increasing time of symptomatic gas would be different between irritable bowel syndrome (IBS) and small intestine bacterial overgrowth (SIBO). The aim of this study was to determine the time for increase in abdominal gas following ingestion of lactulose and the possibility of differential diagnosis of SIBO and IBS. Methods: A prospective study was conducted on a series of IBS patients (n = 14) who were referred to the Oroku-Hospital (Okinawa, Japan) from June 6, 2014 to December 30, 2014. Imaging was first performed in early morning after fasting. After ingestion of lactulose, 1 - 4 plain abdominal radiographs were taken for investigation of increased gas during the indicated timeframe. Regions of interest of the gas areas were highlighted on the images obtained. Gas images were divided into three areas, the stomach, small intestine, and large intestine, and each total area was calculated. Results: At a dose of 10 g lactulose and an observation time of two hours, patients displayed no symptoms, and the gas volume was only slightly increased. However, when the dose of lactulose was increased (13 g/50 kg), and the observation time for the lactulose challenge was extended to 240 - 300 minutes, the results clearly demonstrated an increase in the gas produced in IBS patients. Conclusions: An increased dose of lactulose coupled with an extended observation time for the lactulose challenge clearly demonstrated an increase in the gas produced in IBS patients. Alterations in diet rather than antibiotics might reduce IBS symptoms.

Intestinal bacterial overgrowth in the early stage of severe acute pancreatitis is associated with acute respiratory distress syndrome

BACKGROUND In the early stage of acute pancreatitis(AP),a large number of cytokines induced by local pancreatic inflammation seriously damage the intestinal barrier function,and intestinal bacteria and endotoxins enter the blood,causing inflammatory storm,resulting in multiple organ failure,infectious complications,and other disorders,eventually leading to death.Intestinal failure occurs early in the course of AP,accelerating its development.As an alternative method to detect small intestinal bacterial overgrowth,the hydrogen breath test is safe,noninvasive,and convenient,reflecting the number of intestinal bacteria in AP indirectly.This study aimed to investigate the changes in intestinal bacteria measured using the hydrogen breath test in the early stage of AP to clarify the relationship between intestinal bacteria and acute lung injury(ALI)/acute respiratory distress syndrome(ARDS).Early clinical intervention and maintenance of intestinal barrier function would be highly beneficial in controlling the development of severe acute pancreatitis(SAP).AIM To analyze the relationship between intestinal bacteria change and ALI/ARDS in the early stage of SAP.METHODS A total of 149 patients with AP admitted to the intensive care unit of the Digestive Department,Xuanwu Hospital,Capital Medical University from 2016 to 2019 were finally enrolled,following compliance with the inclusion and exclusion criteria.The results of the hydrogen breath test within 1 wk of admission were collected,and the hydrogen production rates at admission,72 h,and 96 h were calculated.The higher the hydrogen production rates the more bacteria in the small intestine.First,according to the improved Marshall scoring system in the 2012 Atlanta Consensus on New Standards for Classification of Acute Pancreatitis,66 patients with a PaO2/FiO2 score≤1 were included in the mild AP(MAP)group,18 patients with a PaO2/FiO2 score≥2 and duration<48 h were included in the moderately SAP(MSAP)group,and 65 patients with a PaO2/FiO2 score≥2 and duration>48 h were included in the SAP group,to analyze the correlation between intestinal bacterial overgrowth and organ failure in AP.Second,ALI(PaO2/FiO2=2)and ARDS(PaO2/FiO2>2)were defined according to the simplified diagnostic criteria proposed by the 1994 European Union Conference.The MSAP group was divided into two groups according to the PaO2/FiO2 score:15 patients with PaO2/FiO2 score=2 were included in group A,and three patients with score>2 were included in group B.Similarly,the SAP group was divided into two groups:28 patients with score=2 were included in group C,and 37 patients with score>2 were included in group D,to analyze the correlation between intestinal bacterial overgrowth and ALI/ARDS in AP.RESULTS A total of 149 patients were included:66 patients in the MAP group,of whom 53 patients were male(80.3%)and 13 patients were female(19.7%);18 patients in the MSAP group,of whom 13 patients were male(72.2%)and 5 patients were female(27.8%);65 patients in the SAP group,of whom 48 patients were male(73.8%)and 17 patients were female(26.2%).There was no significant difference in interleukin-6 and procalcitonin among the MAP,MSAP,and SAP groups(P=0.445 and P=0.399,respectively).There was no significant difference in the growth of intestinal bacteria among the MAP,MSAP,and SAP groups(P=0.649).There was no significant difference in the growth of small intestinal bacteria between group A and group B(P=0.353).There was a significant difference in the growth of small intestinal bacteria between group C and group D(P=0.038).CONCLUSION Intestinal bacterial overgrowth in the early stage of SAP is correlated with ARDS.

Levothyroxine therapy and impaired clearance are the strongest contributors to small intestinal bacterial overgrowth: Results of a retrospective cohort study

AIM To identify a set of contributors, and weight and rank them on a pathophysiological basis.METHODS Patients who have undergone a lactulose or glucose hydrogen breath test to rule out small intestinal bacterial overgrowth(SIBO) for various clinical symptoms, including diarrhoea, weight loss, abdominal pain, cramping or bloating, were seen as eligible for inclusion in a retrospective single-centre study. Clinical data such as co-morbidities, medication, laboratory parameters and other possible risk factors have been identified from the electronic data system. Cases lacking or with substantially incomplete clinical data were excluded from the analysis. Suspected contributors were summarised under four different pathophysiological pathways(impaired gastric acid barrier, impaired intestinal clearance, immunosuppression and miscellaneous factors including thyroid gland variables) and investigated using the χ2 test, Student's t-test and logistic regression models.RESULTS A total of 1809 patients who had undergone hydrogen breath testing were analysed. Impairment of the gastric acid barrier(gastrectomy, odds ratio: OR = 3.5, PPI therapy OR = 1.4), impairment of intestinal clearance(any resecting gastric surgery OR = 2.6, any colonicresection OR = 1.9, stenosis OR = 3.4, gastroparesis OR = 3.4, neuropathy 2.2), immunological factors(any drug-induced immunosuppression OR = 1.8), altered thyroid gland metabolism(hypothyroidism OR = 2.6, levothyroxine therapy OR = 3.0) and diabetes mellitus(OR = 1.9) were associated significantly to SIBO. Any abdominal surgery, ileocecal resection, vagotomy or Ig A-deficiency did not have any influence, and a history of appendectomy decreased the risk of SIBO. Multivariate analysis revealed gastric surgery, stenoses, medical immunosuppression and levothyroxine to be the strongest predictors. Levothyroxine therapy was the strongest contributor in a simplified model(OR = 3.0).CONCLUSION The most important contributors for the development of SIBO in ascending order are immunosuppression, impairment of intestinal clearance and levothyroxine use, but they do not sufficiently explain its emergence.

Methane production and small intestinal bacterial overgrowth in children living in a slum

AIM:To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests.METHODS:This transversal study included 85 children residing in a slum and 43 children from a private school,all aged between 6 and 10 years,in Osasco,Brazil.For characterization of the groups,data regarding the socioeconomic status and basic housing sanitary conditions were collected.Anthropometric data was obtained in children from both groups.All children completed the hydrogen(H 2) and methane(CH 4) breath test in order to assess small intestinal bacterial overgrowth(SIBO).SIBO was diagnosed when there was an increase in H 2 ≥ 20 ppm or CH 4 ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion.RESULTS:Children from the slum group had worse living conditions and lower nutritional indices than children from the private school.SIBO was found in 30.9%(26/84) of the children from the slum group and in 2.4%(1/41) from the private school group(P = 0.0007).Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school(P = 0.007).A higher concentration of hydrogen in the small intestine(P < 0.001) and in the colon(P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO.Methane production was observed in 63.1%(53/84) of the children from the slum group and in 19.5%(8/41) of the children from the private school group(P < 0.0001).Methane production was observed in 38/58(65.5%) of the children without SIBO and in 15/26(57.7%) of the children with SIBO from the slum.Colonic production of hydrogen was lower in methaneproducing children(P = 0.017).CONCLUSION:Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production.Hydrogen is a substrate for methane production in the colon.

Ileocecal valve dysfunction in small intestinal bacterial overgrowth: A pilot study

AIM: To explore whether patients with a defective ileocecal valve (ICV)/cecal distension reflex have small intestinal bacterial overgrowth. METHODS: Using a colonoscope, under conscious sedation, the ICV was intubated and the colonoscope was placed within the terminal ileum (TI). A manometry catheter with 4 pressure channels, spaced 1 cm apart, was passed through the biopsy channel of the colonoscope into the TI. The colonoscope was slowly withdrawn from the TI while the manometry catheter was advanced. The catheter was placed across the ICV so that at least one pressure port was within the TI, ICV and the cecum respectively. Pressures were continuously measured during air insufflation into the cecum, under direct endoscopic visualization, in 19 volunteers. Air was insufflated to a maximum of 40 mmHg to prevent barotrauma. All subjects underwent lactulose breath testing one month after the colonoscopy. The results of the breath tests were compared with the results of the pressures within the ICV during air insufflation. RESULTS: Nineteen subjects underwent colonoscopy with measurements of the ICV pressures after intubation of the ICV with a colonoscope. Initial baseline readings showed no statistical difference in the pressures of the TI and ICV, between subjects with positive lactulose breath tests and normal lactulose breath tests. The average peak ICV pressure during air insufflation into the cecum in subjects with normal lactu-lose breath tests was significantly higher than cecal pressures during air insufflation (49.33 ± 7.99 mmHg vs 16.40 ± 2.14 mmHg, P = 0.0011). The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflations in subjects with normal lactulose breath tests was significantly higher (280.72% ± 43.29% vs 100% ± 0%, P = 0.0006). The average peak ICV pressure during air insufflation into the cecum in subjects with positive lactulose breath tests was not significantly different than cecal pressures during air insufflation 21.23 ± 3.52 mmHg vs 16.10 ± 3.39 mmHg. The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflation was not significantly different 101.08% ± 7.96% vs 100% ± 0%. The total symptom score for subjects with normal lactulose breath tests and subjects with positive lactu-lose breath tests was not statistically different (13.30 ± 4.09 vs 24.14 ± 6.58). The ICV peak pressures during air insufflations were significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.005). The average percent difference of the area under the pressure curve in the ICV from cecum was significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.0012). Individuals with positive lactulose breath tests demonstrated symptom scores which were significantly higher for the following symptoms: not able to finish normal sized meal, feeling excessively full after meals, loss of appetite and bloating. CONCLUSION: Compared to normal, subjects with a positive lactulose breath test have a defective ICV cecal distension reflex. These subjects also more commonly have higher symptom scores.

Breath tests and irritable bowel syndrome

Breath tests are non-invasive tests and can detect H2 and CH4 gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath. These tests are used in the diagnosis of carbohydrate malabsorption, small intestinal bacterial overgrowth, and for measuring the orocecal transit time. Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome (IBS)-type symptoms such as diarrhea and/or constipation, bloating, excess flatulence, headaches and lack of energy. Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life. It may reflect dietary imbalance, such as excess fiber intake, or may be a manifestation of IBS. However, bloating may also represent small intestinal bacterial overgrowth. Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H2 breath testing to determine the presence or absence of bacterial overgrowth. If bacterial overgrowth is identified, patients are typically treated with antibiotics. Evaluation of IBS generally includes testing of other disorders that cause similar symptoms. Carbohydrate malabsorption (lactose, fructose, sorbitol) can cause abdominal fullness, bloating, nausea, abdominal pain, flatulence, and diarrhea, which are similar to the symptoms of IBS. However, it is unclear if these digestive disorders contribute to or cause the symptoms of IBS. Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS. Thus, diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients.

Probiotic effects on intestinal fermentation patterns in patients with irritable bowel syndrome

AIM： To determine whether Lactobacillus casei strain Shirota （Yakult） can alter small intestinal bacterial overgrowth （SIBO）, as tested by the lactulose breath test, and whether this is associated with changes in symptoms in irritable bowel syndrome （IBS）. METHODS： 18 patients with IBS （Rome Ⅱ criteria）, who showed an early rise in breath hydrogen with lactulose （ERBHAL）, consumed 65 mL of Yakult daily for 6 wk. Lactulose breath test was repeated at the end of the treatment period. Symptoms were recorded daily using a 10 cm visual analogue scale. RESULTS： 14 patients completed the study, 9 （64%） had reversal of ERBHAL, with the median time of first rise in breath hydrogen increasing from 45 to 75 min （P = 0.03）. There was no significant improvement in the symptom score with probiotic therapy, except for wind （P = 0.04）. Patients commencing with at least moderate symptoms and who no longer had ERBHAL at the end of treatment, showed improvement in the overall symptoms scores [median final score 5.3 （IQR 3.9-5.9）, 55% reduction; n = 6] to a greater extent than those who had had persisting ERBHAL [final score 6.9 （5.0-7.0）, 12% reduction; n = 5; P = 0.18]. CONCLUSION： Yakult is effective in altering fermentation patterns in the small bowel, consistent with reducing SIBO. The loss of ERBHAL was associated with reduced symptoms. The true interpretation of these findings awaits a randornised, controlled trial.

Gastrointestinal motility and absorptive disorders in patients with inflammatory bowel diseases: Prevalence, diagnosis and treatment

Inflammatory bowel diseases(IBD),Crohns disease and ulcerative colitis,are chronic conditions associated with high morbidity and healthcare costs.The natural history of IBD is variable and marked by alternating periods of flare and remission.Even though the use of newer therapeutic targets has been associated with higher rates of mucosal healing,a great proportion of IBD patients remain symptomatic despite effective control of inflammation.These symptoms may include but not limited to abdominal pain,dyspepsia,diarrhea,urgency,fecal incontinence,constipation or bloating.In this setting,commonly there is an overlap with gastrointestinal(GI)motility and absorptive disorders.Early recognition of these conditions greatly improves patient care and may decrease the risk of mistreatment.Therefore,in this review we describe the prevalence,diagnosis and treatment of GI motility and absorptive disorders that commonly affect patients with IBD.

Glucose substrate in the hydrogen breath test for gut microbiota determination:A recommended noninvasive test

Intestinal dysbiosis and small intestinal bacterial overgrowth(SIBO)are common in patients with liver cirrhosis.Existing studies have not explored the association between gut dysbiosis and SIBO.We propose some suggestions for the authors’experimental methods and concepts,and we hope these suggestions can be adopted.The hydrogen breath test is worthy of recommendation due to its high accuracy and convenient operation.We suggest changing the substrate of the hydrogen breath test from lactulose to glucose to improve the accuracy of each parameter.SIBO is a small subset of gut dysbiosis,and we propose clarifying the concept of both.SIBO may be caused by liver cirrhosis or one of the pathogeneses of gastrointestinal diseases.Therefore,interference from other gastrointestinal diseases should be excluded from this study.

Overgrowth of the indigenous gut microbiome and irritable bowel syndrome

Culture-independent molecular techniques have demonstrated that the majority of the gut microbiota is uncultivable.Application of these molecular techniques to more accurately identify the indigenous gut microbiome has moved with great pace over recent years,leading to a substantial increase in understanding of gut microbial communities in both health and a number of disorders,including irritable bowel syndrome(IBS).Use of culture-independent molecular techniques already employed to characterise faecal and,to a lesser extent,colonic mucosal microbial populations in IBS,without reliance on insensitive,traditional microbiological culture techniques,has the potential to more accurately determine microbial composition in the small intestine of patients with this disorder,at least that occurring proximally and within reach of sampling.Current data concerning culture-based and culture-independent analyses of the small intestinal microbiome in IBS are considered here.

肠易激综合征患者合并非酒精性脂肪性肝病的临床特征及相关因素分析

目的探讨肠易激综合征(irritable bowel syndrome,IBS)患者合并非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)的临床特征及危险因素。方法回顾性分析2020年6月至2023年6月于中国人民解放军总医院第六医学中心消化内科就诊的IBS患者,根据是否合并NAFLD将患者分为IBS-NAFLD组和IBS-非NAFLD组,比较两组患者的临床特征,包括一般临床资料、实验室检查结果和腹部症状,并用多因素Logistic回归分析筛选出IBS合并NAFLD的危险因素。结果共纳入145例IBS患者。其中IBS-NAFLD组78例(53.8%),IBS-非NAFLD组67例(46.2%)。多因素Logistic回归分析显示,年龄增长、BMI增加、高血压、TBA水平升高、TG水平升高、SIBO阳性是IBS合并NAFLD的独立危险因素。在腹部症状上,与IBS-非NAFLD组相比,IBS-NAFLD组的腹泻、腹胀、排气较多症状发生率显著增加(P<0.05)。两组出现口腔异味、食物过敏或不耐受、食欲不振、嗳气、消化不良、烧心反酸、腹痛、恶心、便秘、腹泻与便秘交替、里急后重、便腥臭且黏稠的比例差异均无统计学意义(P>0.05)。结论NAFLD在IBS患者中并不少见。年龄、BMI、血压、TBA水平、TG水平、SIBO是IBS患者合并NAFLD的独立危险因素。临床医师应重视对上述因素的控制,以减少IBS合并NAFLD风险的发生。

Prevalence of restless legs syndrome in patients with irritable bowel syndrome

AIM:To determine the prevalence of restless legs syndrome(RLS)in patients with irritable bowel syndrome(IBS).METHODS:Patients with diarrhea-predominant IBS(n=30),constipation-predominant IBS(n=30),or mixed-symptom IBS(n=30)were recruited from the community between March 2008 and February 2009.Rifaximin 200 mg three times daily was administered empirically to alleviate small intestinal bowel over-growth in all patients.The presence of RLS was assessed via an RLS questionnaire and polysomnography.RESULTS:Twentysix patients with IBS(29%)were diagnosed with RLS using the RLS questionnaire.Twenty-four of the 26 patients(92%)underwent polysomnog-raphy,and all had confirmation of RLS.A greater percentage of patients with RLS had diarrhea-predominant IBS(62%)compared with patients with constipation-predominant IBS(4%)or mixed-symptom IBS(33%).CONCLUSION:Restless legs syndrome is prevalent in patients with IBS,especially those with diarrheal symptoms.Assessment of concomitant disorders may improve diagnosis and expand relevant treatment options for patients.

Serum-Derived Bovine Immunoglobulin/Protein Isolate Therapy for Patients with Refractory Irritable Bowel Syndrome

Background: A small double-blind study showed benefits of serum-derived bovine immunoglobulin/protein isolate (SBI), for diarrhea-predominant irritable bowel syndrome (IBS-D) [1]. The purpose of this chart review was to assess safety and clinical outcomes of SBI in refractory irritable bowel syndrome (IBS) patients. Methods: A retrospective review of 35 IBS patients with diarrhea or mixed diarrhea/constipation pattern (IBS-M) who were administered SBI 5 grams twice daily was performed. Clinical response (“good response” or “no response”) and adverse events were determined by follow-up after four weeks of therapy. Patients were included for evaluation if a lactulose breath test (LBT) had been performed prior to SBI. All patients were refractory to common IBS therapies. The response rate to the inclusion of SBI was calculated in three separate groups: dividing patients based on their LBT results (positive or negative), dividing patients by their IBS diagnosis (IBS-D or IBS-M) and grouping all patients together. Results: Analysis was carried out on 26 IBS-D/-M patients with LBT results. Two patients were lost to follow-up and were excluded from data analysis. The positive LBT group (N = 11) had a 73% (p = 0.117) positive response rate to SBI. The negative LBT group (N = 13) had a significant response rate of 77% (p = 0.040). If patients were divided by IBS diagnosis or grouped together, the response rate to SBI was similarly ranging from 69% - 88%. Adverse events leading to cessation of SBI occurred in 3 of 24 patients. Conclusion: SBI appeared to be a safe and effective nutritional moiety in refractory IBS-D and IBS-M patients. Larger, double-blind studies are needed.

小肠细菌过度生长的检测及其在肠易激综合征诊治中的临床意义

小肠细菌过度生长(small intestinal bacterial overgrowth,SIBO)是肠道菌群失调的一种特殊表现,可引起肠道局部炎症和免疫变化,进而引发多种消化系统症状,如腹泻、腹痛、腹胀和营养吸收障碍等。目前,SIBO在肠易激综合征发病中的作用已越来越受到关注。本文就SIBO的健康危害、SIBO检测方法和SIBO检测在肠易激综合征诊治中的临床意义作一综述。