Evaluating the accuracy and reproducibility of ChatGPT-4 in answering patient questions related to small intestinal bacterial overgrowth

BACKGROUND Small intestinal bacterial overgrowth(SIBO)poses diagnostic and treatment challenges due to its complex management and evolving guidelines.Patients often seek online information related to their health,prompting interest in large language models,like GPT-4,as potential sources of patient education.AIM To investigate ChatGPT-4's accuracy and reproducibility in responding to patient questions related to SIBO.METHODS A total of 27 patient questions related to SIBO were curated from professional societies,Facebook groups,and Reddit threads.Each question was entered into GPT-4 twice on separate days to examine reproducibility of accuracy on separate occasions.GPT-4 generated responses were independently evaluated for accuracy and reproducibility by two motility fellowship-trained gastroenterologists.A third senior fellowship-trained gastroenterologist resolved disagreements.Accuracy of responses were graded using the scale:(1)Comprehensive;(2)Correct but inadequate;(3)Some correct and some incorrect;or(4)Completely incorrect.Two responses were generated for every question to evaluate reproducibility in accuracy.RESULTS In evaluating GPT-4's effectiveness at answering SIBO-related questions,it provided responses with correct information to 18/27(66.7%)of questions,with 16/27(59.3%)of responses graded as comprehensive and 2/27(7.4%)responses graded as correct but inadequate.The model provided responses with incorrect information to 9/27(33.3%)of questions,with 4/27(14.8%)of responses graded as completely incorrect and 5/27(18.5%)of responses graded as mixed correct and incorrect data.Accuracy varied by question category,with questions related to“basic knowledge”achieving the highest proportion of comprehensive responses(90%)and no incorrect responses.On the other hand,the“treatment”related questions yielded the lowest proportion of comprehensive responses(33.3%)and highest percent of completely incorrect responses(33.3%).A total of 77.8%of questions yielded reproducible responses.CONCLUSION Though GPT-4 shows promise as a supplementary tool for SIBO-related patient education,the model requires further refinement and validation in subsequent iterations prior to its integration into patient care.

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.

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.

Subclinical atherosclerosis is linked to small intestinal bacterial overgrowth via vitamin K2-dependent mechanisms

To assess the rate of matrix Gla-protein carboxylation in patients with small intestinal bacterial overgrowth (SIBO) and to decipher its association with subclinical atherosclerosis.METHODSPatients with suspected SIBO who presented with a low risk for cardiovascular disease and showed no evidence of atherosclerotic plaques were included in the study. A glucose breath test was performed in order to confirm the diagnosis of SIBO and vascular assessment was carried out by ultrasound examination. Plasma levels of the inactive form of MGP (dephosphorylated-uncarboxylated matrix Gla-protein) were quantified by ELISA and vitamin K2 intake was estimated using a food frequency questionnaire.RESULTSThirty-nine patients were included in the study. SIBO was confirmed in 12/39 (30.8%) patients who also presented with a higher concentration of dephosphorylated-uncarboxylated matrix Gla-protein (9.5 μg/L vs 4.2 μg/L; P = 0.004). Arterial stiffness was elevated in the SIBO group (pulse-wave velocity 10.25 m/s vs 7.68 m/s; P = 0.002) and this phenomenon was observed to correlate linearly with the levels of dephosphorylated-uncarboxylated matrix Gla-protein (β = 0.220, R2 = 0.366, P = 0.03). Carotid intima-media thickness and arterial calcifications were not observed to be significantly elevated as compared to controls.CONCLUSIONSIBO is associated with reduced matrix Gla-protein activation as well as arterial stiffening. Both these observations are regarded as important indicators of subclinical atherosclerosis. Hence, screening for SIBO, intestinal decontamination and supplementation with vitamin K2 has the potential to be incorporated into clinical practice as additional preventive measures.

Gut dysbiosis and small intestinal bacterial overgrowth as independent forms of gut microbiota disorders in cirrhosis

BACKGROUND Gut dysbiosis and small intestinal bacterial overgrowth(SIBO)are commonly observed in patients with cirrhosis.Despite the substantial number of articles describing the relations between disorders of gut microbiota and various manifestations of cirrhosis,dysbiosis and SIBO were always studied separately.AIM To study the relationship of gut dysbiosis and SIBO in cirrhosis.METHODS This observational study included 47 in-patients with cirrhosis.Stool microbiome was assessed using 16 S r RNA gene sequencing.SIBO was assessed using the lactulose hydrogen breath test.RESULTS SIBO was found in 24/47(51.1%)patients.Patients with SIBO had a higher abundance of Firmicutes(P=0.017)and Fusobacteria(P=0.011),and a lower abundance of Bacteroidetes(P=0.013)than patients without SIBO.This increase in the abundance of Firmicutes occurred mainly due to an increase in the abundance of bacteria from the genus Blautia(P=0.020)of the Lachnospiraceae family(P=0.047),while the abundance of other major families of this phylum[Ruminococcaceae(P=0.856),Peptostreptococcaceae(P=0.066),Clostridiaceae(P=0.463),Eubacteriaceae(P=0.463),Lactobacillaceae(P=0.413),and Veillonellaceae(P=0.632)]did not differ significantly between the patients with and without SIBO.Reduced level of Bacteroidetes in samples from patients with SIBO was a result of the decrease in bacterial numbers from all the major families of this phylum[Bacteroidaceae(P=0.014),Porphyromonadaceae(P=0.002),and Rikenellaceae(P=0.047)],with the exception of Prevotellaceae(P=0.941).There were no significant differences in the abundance of taxa that were the main biomarkers of cirrhosis-associated gut dysbiosis[Proteobacteria(P=0.790),Bacilli(P=0.573),Enterobacteriaceae(P=0.632),Streptococcaceae(P=0.170),Staphylococcaceae(P=0.450),and Enterococcaceae(P=0.873)]between patients with and without SIBO.CONCLUSION Despite the differences observed in the gut microbiome between patients with and without SIBO,gut dysbiosis and SIBO are most likely independent disorders of gut microbiota in cirrhosis.

Helicobacter pylori infection and small intestinal bacterial overgrowth–more than what meets the eye

Helicobacter pylori(H.pylori)infection is very common and affects a significant proportion of the world population.In contrast,the prevalence of small intestinal bacterial overgrowth(SIBO)in the general population is not well understood.There can be coexistence of both disease states in a given patient and their clinical symptoms may also overlap with one and another.There is no clear clinical guidelines for testing for and treating SIBO in patients with H.pylori infection.This review article explores the available evidence on the relationship between H.pylori infection and SIBO,diagnosis and treatment of these entities and also comments on associated non-gastrointestinal conditions.

Assessment of small intestinal bacterial overgrowth in uncomplicated acute diverticulitis of the colon

AIM: Small intestinal bacterial overgrowth (SIBO) maycontribute to the appearance of several gastrointestinal nonspecific symptoms. Acute diverticulitis is affected by some similar symptoms and bacterial colonic overgrowth. We assessed the prevalence of SIBO in acute uncomplicated diverticulitis and evaluated its influence on the clinical course of the disease.METHODS: We studied 90 consecutive patients (39 males, 51 females, mean age 67.2 years, range 32-91 years). Sixty-one patients (67.78%) and 29 patients (32.22%) were affected by constipation-or diarrhea-prevalent diverticulitis respectively. All subjects were investigated by lactulose H2-breath test at the entry and at the end of treatment. We also studied a control group of 20 healthy subjects (13 males, 7 females, mean age 53 years, range 22-71 years).RESULTS: Oro-cecal transit time (OCTT) was delayed in67/90 patients (74.44%) (range 115-210 min, mean 120 min). Fifty-three of ninety patients (58.88%) showed SIBO, while OCTT was normal in 23/90 patients (25, 56%). In the control group, the mean OCTT was 88.2 min (range 75-135 min). The difference between diverticulitic patients and healthy subjects was statistically significant (P＜0.01). OCTT was longer in constipation-prevalent disease than in diarrheaprevalent disease [180.7 min (range 150-210 min) vs 121 min (range 75-180 min) (P＜0.001)], but no difference in bacterial overgrowth was found between the two forms of diverticulitis.After treatment with rifaximin plus mesalazine for 10 d, followed by mesalazine alone for 8 wk, 70 patients (81.49%) were completely asymptomatic, while 16 patients (18.60%) showed only slight symptoms. Two patients (2.22%) had recurrence of diverticulitis, and two other patients (2.22%) were withdrawn from the study due to side-effects. Seventy-nine of eighty-six patients (91.86%) showed normal OCTT (range 75-105 min, mean 83 min), while OCTT was longer, but it was shorter in the remaining seven (8.14%) patients (range 105-115 min, mean of 110 min). SIBO was eradicated in all patients, while it persisted in one patient with recurrence of diverticulitis. CONCLUSION: SIBO affects most of the patients with acute diverticulitis. SIBO may worsen the symptoms of patients and prolong the clinical course of the disease, as confirmed in the case of persistence of SIBO and diverticulitis recurrence. In this case, we can hypothesize that bacteria from small bowel may re-colonize in the colon and provoke recurrence of symptoms.

Diet and intestinal bacterial overgrowth: Is there evidence?

The intestinal microbiota and its role in health and disease processes have been the subject of several studies.It is known that changes in the intestinal microbiota occur due to several factors,such as the use of medication,age,lifestyle and diseases,which can modify intestinal homeostasis and lead to excessive growth of bacteria in the small intestine,triggering a clinical condition called small bowel bacterial overgrowth(SIBO).Individuals with SIBO may present gastrointestinal symptoms ranging from nausea,diarrhea and/or constipation,and flatulence to distension and abdominal pain,resulting from poor absorption of nutrients or changes in intestinal permeability.The gold-standard treatment is based on the use of antibiotics to eradicate bacterial overgrowth.Some studies have evaluated diets in the treatment of SIBO;however,the studies are of low methodological quality,making extrapolation of the results to clinical practice unfeasible.Thus,there is still not enough scientific evidence to support a specific type of diet for the treatment of SIBO.

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.

Association between small intestinal bacterial overgrowth and deep vein thrombosis

Objective:Small intestinal bacterial overgrowth(SIBO)has been associated with several diseases.The association between SIBO and deep vein thrombosis(DVT)has not been investigated.This study was aimed to investigate the frequency and risk factors for the development of DVT in patients tested for SIBO.Methods:All 321 eligible patients were included from the Cleveland Clinic Gastrointestinal Motility Lab databank from January 2008 to January 2014.Patients who were evaluated with glucose hydrogen/methane breath test as well as Doppler ultrasonography for suspected DVT were included.Patients with catheter-related DVT were excluded.The primary outcomes were the frequency and risk factors(including SIBO)for DVT in this patient population.Results:Of the 321-case cohort,144 patients(44.9%)tested positive for SIBO,and 53(16.5%)had ultrasonographic findings of DVT.SIBO evaluation before the evaluation of DVT occurred in 201 patients(median time from the breath test to ultrasonography:27 months;interquartile range[IQR]:11.0–45.0 months),and SIBO evaluation after evaluation for DVT occurred in 120 patients(median time from ultrasonography to the breath test:30 months;IQR:11.8–54.3 months).In the univariate analysis,DVT was associated with family history of thromboembolic events(35.8%vs 16.0%,P=0.001),chronic kidney diseases(CKD;26.4%vs 13.4%,P=0.019)and the presence of SIBO(69.8%vs 39.9%,P50.001).In themultivariate analysis,family history of thromboembolic events(odds ratio[OR]:3.39;95%confidence interval[CI]:1.67–6.87;P50.001),CKD(OR:2.23;95%CI:1.04–4.74;P=0.037),and the presence of SIBO(OR:3.27;95% CI:1.70–6.32;P50.001)remained independently associated with DVT.Conclusion:SIBO was found to be associated with DVT.The nature of this association warrants further investigation.

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.

Progress in elucidating the relationship between Helicobacter pylori infection and intestinal diseases

Helicobacter pylori(H.pylori)infection causes changes to the intestinal flora,such as small intestinal bacterial overgrowth,and increases gastric acid secretionstimulating gastrointestinal hormones,mainly gastrin,due to a decrease in gastric acid caused by atrophic gastritis.In addition,the cellular components of H.pylori travel through the intestinal tract,so the bacterial infection affects the immune system.Therefore,the effects of H.pylori infection are observed not only in the stomach and the proximal duodenum but also in the small and large intestines.In particular,meta-analyses reported that H.pylori-infected individuals had an increased risk of colorectal adenoma and colorectal cancer.Moreover,a recent study reported that the risk of developing colorectal cancer was increased in subjects carrying H.pylori vacuolating cytotoxin A antibody.In addition,it has been reported that H.pylori infection exacerbates the symptoms of Fabry’s disease and familial Mediterranean fever attack and is involved in irritable bowel syndrome and small intestinal ulcers.On the other hand,some studies have reported that the frequency of ulcerative colitis,Crohn’s disease,and celiac disease is low in H.pylori-infected individuals.Thus,H.pylori infection is considered to have various effects on the small and large intestines.However,few studies have reported on these issues,and the details of their effects have not been well elucidated.Therefore,additional studies are needed.

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.

Gut-liver axis and probiotics: Their role in non-alcoholic fatty liver disease

The incidence of obesity and its related conditions, including non-alcoholic fatty liver disease (NAFLD), has dramatically increased in all age groups worldwide. Given the health consequences of these conditions, and the subsequent economic burden on healthcare systems, their prevention and treatment have become major priorities. Because standard dietary and lifestyle changes and pathogenically-oriented therapies (e.g., antioxidants, oral hypoglycemic agents, and lipid-lowering agents) often fail due to poor compliance and/or lack of efficacy, novel approaches directed toward other pathomechanisms are needed. Here we present several lines of evidence indicating that, by increasing energy extraction in some dysbiosis conditions or small intestinal bacterial overgrowth, specific gut microbiota and/or a &#x0201c;low bacterial richness&#x0201d; may play a role in obesity, metabolic syndrome, and fatty liver. Under conditions involving a damaged intestinal barrier (&#x0201c;leaky gut&#x0201d;), the gut-liver axis may enhance the natural interactions between intestinal bacteria/bacterial products and hepatic receptors (e.g., toll-like receptors), thus promoting the following cascade of events: oxidative stress, insulin-resistance, hepatic inflammation, and fibrosis. We also discuss the possible modulation of gut microbiota by probiotics, as attempted in NAFLD animal model studies and in several pilot pediatric and adult human studies. Globally, this approach appears to be a promising and innovative add-on therapeutic tool for NAFLD in the context of multi-target therapy.

Washed microbiota transplantation reduces proton pump inhibitor dependency in nonerosive reflux disease

BACKGROUND The pathogenesis of gastroesophageal reflux disease(GERD)is closely associated with the intestinal bacteria composition and their metabolites.AIM To investigate whether washed microbiota transplantation(WMT)improves symptoms of nonerosive reflux disease(NERD)with proton pump inhibitor(PPI)dependency.METHODS Patients with recurrent NERD and PPI dependency at the First Affiliated Hospital of Guangdong Pharmaceutical University from 2017 to 2018 were included and divided into a WMT or PPI group treated with PPI with/without WMT.The endpoint was NERD symptom frequency evaluated 1 mo after WMT using reflux disease questionnaire(RDQ)and GERD questionnaire(GERDQ)scores,remission time,PPI dose,and the examination of intestinal mucosal barrier function.RESULTS In the WMT(n=15)and PPI(n=12)groups,the total remission rate at 1 mo after treatment was 93.3%vs 41.7%.Compared with the PPI group,the WMT group showed better results in GERDQ(P=0.004)and RDQ(P=0.003)and in remission months(8 vs 2,P=0.002).The PPI dose was reduced to some extent for 80%of patients in the WMT group and 33.3%in the PPI group.In 24 patients,intestinal mucosal barrier function was examined before treatment,and changes in the degree of damage were observed in 13 of these patients after treatment.Only one of the 15 patients had minor side effects,including a mushy stool two or three times a day,which resolved on their own after 1 wk.CONCLUSION This study is the first to demonstrate that WMT may be safe and effective for relieving NERD symptoms and reducing PPI dependency and recurrence.

Gut-liver axis in cirrhosis:Are hemodynamic changes a missing link?

Recent evidence suggests that the condition of the gut and its microbiota greatly influence the course of liver disease,especially cirrhosis.This introduces the concept of the gut-liver axis,which can be imagined as a chain connected by several links.Gut dysbiosis,small intestinal bacterial overgrowth,and intestinal barrier alteration lead to bacterial translocation,resulting in systemic inflammation.Systemic inflammation further causes vasodilation,arterial hypotension,and hyperdynamic circulation,leading to the aggravation of portal hypertension,which contributes to the development of complications of cirrhosis,resulting in a poorer prognosis.The majority of the data underlying this model were obtained initially from animal experiments,and most of these correlations were further reproduced in studies including patients with cirrhosis.However,despite the published data on the relationship of the disorders of the gut microbiota with the complications of cirrhosis and the proposed pathogenetic role of hemodynamic disorders in their development,the direct relations between gut dysbiosis and hemodynamic changes in this disease are poorly studied.They remain a missing link in the gut-liver axis and a challenge for future research.

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.

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.

Patients with breath test positive are necessary to be identified from irritable bowel syndrome:a clinical trial based on microbiomics and rifaximin sensitivity

Background:As a non-invasive and effective diagnostic method for small intestinal bacterial overgrowth(SIBO),wild-use of breath test(BT)has demonstrated a high comorbidity rate in patients with diarrhea-predominant irritable bowel syndrome(IBS-D)and SIBO.Patients overlapping with SIBO respond better to rifaximin therapy than those with IBS-D only.Gut microbiota plays a critical role in both of these two diseases.We aimed to determine the microbial difference between IBS-D overlapping with/without SIBO,and to study the underlying mechanism of its sensitivity to rifaximin.Methods:Patients with IBS-D were categorized as BT-negative(IBSN)and BT-positive(IBSP).Healthy volunteers(BT-negative)were enrolled as healthy control.The patients were clinically evaluated before and after rifaximin treatment(0.4 g bid,4 weeks).Blood,intestine,and stool samples were collected for cytokine assessment and gut microbial analyses.Results:Clinical complaints and microbial abundance were significantly higher in IBSP than in IBSN.In contrast,severe systemic inflammation and more active bacterial invasion function that were associated with enrichment of opportunistic pathogens were seen in IBSN.The symptoms of IBSP patients were relieved in different degrees after therapy,but the symptoms of IBSN rarely changed.We also found that the presence of IBSN-enriched genera(Enterobacter and Enterococcus)are unaffected by rifaximin therapy.Conclusions:IBS-D patients overlapping with SIBO showed noticeably different fecal microbial composition and function compared with IBS-D only.The better response to rifaximin in those comorbid patients might associate with their different gut microbiota,which suggests that BT is necessary before IBS-D diagnosis and use of rifaximin.Registration:Chinese Clinical Trial Registry,ChiCTR1800017911.

Selection of a cut-off for high-and low-methane producers using a spot-methane breath test:results from a large north American dataset of hydrogen,methane and carbon dioxide measurements in breath

Background:Levels of breath methane,together with breath hydrogen,are determined by means of repeated collections of both,following ingestion of a carbohydrate substrate,at 15–20 minutes intervals,until 10 samples have been obtained.The frequent sampling is required to capture a rise of hydrogen emissions,which typically occur later in the test:in contrast,methane levels are typically elevated at baseline.If methane emissions represent the principal objective of the test,a spot methane test(i.e.a single-time-point sample taken after an overnight fast without administration of substrate)may be sufficient.Methods:We analysed 10-sample lactulose breath test data from 11674 consecutive unique subjects who submitted samples to Commonwealth Laboratories(Salem,MA,USA)from sites in all of the states of the USA over a one-year period.The North American Consensus(NAC)guidelines criteria for breath testing served as a reference standard.Results:The overall prevalence of methane-positive subjects(by NAC criteria)was 20.4%,based on corrected methane results,and 18.9% based on raw data.In our USA dataset,the optimal cut-off level to maximize sensitivity and specificity was4ppm CH4,94.5%[confidence interval(CI):93.5–95.4%]and 95.0%(CI:94.6–95.5%),respectively.The use of a correction factor(CF)(5%CO_(2) as numerator)led to reclassifications CH4-high to CH_(4)-low in 0.7% and CH_(4)-low to CH_(4)-high in 2.1%.Conclusions:A cut-off value for methane at baseline of either≥4 ppm,as in our USA dataset,or≥5 ppm,as described in a single institution study,are both highly accurate in identifying subjects at baseline that would be diagnosed as‘methanepositive’in a 10-sample lactulose breath test for small intestinal bacterial overgrowth.