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.

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.

胃食管反流病并小肠细菌过度生长患者的临床特征及利福昔明治疗效果研究

目的 探究胃食管反流病(GERD)并小肠细菌过度生长(SIBO)患者的临床特征,并进一步探究利福昔明对此类患者治疗效果。方法 统计2022年1月至2023年01月就诊于邯郸市中心医院及邯郸市第一医院的符合胃食管反流病纳入标准的患者149例,依据乳果糖氢-甲烷呼气试验(LHBT)结果,将其分为GERD合并SIBO组(GERD-P组)与不合并SIBO组(GERD-N组)。比较两组在一般资料(性别、年龄、体重指数BMI)与临床资料(不典型症状、食管外症状、并发症、内镜下表现、GERDQ评分、RDQ评分、GERD-HRQL评分)方面的区别。随后将GERD-P组随机分为治疗组(给予艾普拉唑10 mg qd联合利福昔明0.2 g tid治疗4周)和对照组(单独给予艾普拉唑10 mg qd治疗4周),通过临床资料评价利福昔明治疗效果。结果GERD-P组与GERD-N组相比,两组性别比例、年龄无差异(P>0.05),GERD-P组的BMI,不典型症状、食管外症状及并发症比例,内镜下表现严重程度,GERDQ评分,RDQ评分,GERD-HRQL评分均高于GERD-N组,有统计学意义(P<0.05)。治疗4周后,治疗组与对照组相比,两组在并发症方面无差异(P>0.05),治疗组在不典型症状、食管外症状、内镜下表现缓解情况及GERDQ评分、RDQ评分、GERD-HRQL评分方面均优于对照组,有统计学意义(P<0.05)。结论 高BMI的GERD患者更容易合并SIBO,GERD合并SIBO患者的临床症状及相关量表评分均较GERD不合并SIBO患者严重。对合并SIBO的GERD患者,艾普拉唑联合利福昔明治疗临床效果优于单独艾普拉唑治疗效果。

小肠细菌过度生长的治疗新进展

小肠细菌过度生长(SIBO)是由多种因素引起的小肠细菌含量高于正常值,并且与肠易激综合征、炎症性肠病等多种疾病相关。目前,关于SIBO的治疗方法仍有争议。因此,本文对SIBO的治疗进行综述,包括抗菌药物、益生菌、促动力药、中草药、饮食疗法及其他治疗方法。

不同方案治疗幽门螺杆菌感染合并小肠细菌过度生长的疗效分析

目的比较不同治疗方案对于幽门螺杆菌(Helicobacter pylori,Hp)感染合并小肠细菌过度生长(small intestinal bacterial overgrowth,SIBO)的治疗情况。方法纳入2022年4月至2023年7月在中国人民解放军总医院第六医学中心消化内科门诊及住院部就诊的Hp和SIBO共同阳性的患者。将纳入患者随机分为A、B、C三组,A组患者给予铋剂四联方案根除Hp后使用利福昔明清除小肠细菌;B组患者使用利福昔明清除小肠细菌后行铋剂四联方案根除Hp;C组患者同时给予铋剂四联方案及利福昔明治疗Hp和SIBO。分别停药4~6周后复查13C尿素呼气试验与甲烷氢呼气试验。比较三组Hp和SIBO共同转阴率、腹部症状评分改善程度和腹泻、便秘、恶心等不良反应的发生情况。结果三组Hp转阴率差异无统计学意义(P>0.05),B组的SIBO转阴率、共同转阴率高于A组(P<0.05),B组与C组相比差异无统计学意义(P>0.05)。治疗后B组GSRS评分改善程度高于A、C组(P=0.015,P=0.014),B组整体不良反应低于A组(P<0.001)。B、C组整体不良反应差异无统计学意义(P>0.05)。A组的SIBO转阴率、共同转阴率、治疗后GSRS评分改善程度与C组差异无统计学意义(P>0.05),A组不良反应发生率高于C组(P=0.004)。结论Hp感染合并SIBO患者多数伴有反酸、烧心、腹胀、便秘、腹泻等胃肠道不适,清除小肠细菌后行Hp治疗可提高Hp和SIBO共同的转阴率,并有效减轻腹部症状,减少不良反应的发生。

香砂六君子汤联合枯草杆菌二联活菌肠溶胶囊治疗脾胃气虚型乙肝肝硬化合并小肠细菌过度生长的临床疗效观察

[目的]探讨香砂六君子汤联合枯草杆菌二联活菌肠溶胶囊治疗脾胃气虚型乙肝肝硬化合并小肠细菌过度生长(SIBO)的疗效。[方法]连续性招募2020年12月至2022年12月收治的80例乙肝肝硬化合并SIBO患者,采用随机数字表法将其分为两组,每组各40例。对照组给予枯草杆菌二联活菌肠溶胶囊治疗,观察组给予香砂六君子汤联合枯草杆菌二联活菌肠溶胶囊治疗。观察两组疗效、SIBO转阴率、中医证候积分、肝功能、免疫功能、炎症因子和不良反应。[结果]观察组总有效率和治疗14 d SIBO转阴率高于对照组(P<0.05)。两组治疗后食欲不振,脘腹痞胀食后尤甚,大便溏泄,神疲肢倦,头晕乏力证候积分较治疗前降低(P<0.05),血清谷草转氨酶(AST)、谷丙转氨酶(ALT)、总胆红素(TBiL)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平,外周血CD8^(+)占比较治疗前降低(P<0.05),总蛋白(TP)、外周血CD3^(+)、CD4^(+)占比较治疗前增高(P<0.05),观察组治疗后中医证候积分,血清ΑST、ALT、IL-6、TNF-α水平,外周血CD8^(+)占比低于对照组(P<0.05),外周血CD3^(+)、CD4^(+)占比、CD4^(+)/CD8^(+)高于对照组(P<0.05)。[结论]香砂六君子汤联合枯草杆菌二联活菌肠溶胶囊可更显著改善临床症状,提高T淋巴细胞免疫功能和抑制炎症反应,在治疗乙肝肝硬化合并SIBO方面具有更显著的临床疗效。

幽门螺杆菌与小肠细菌过度生长的相关性研究

我国人口感染H.pylori的人数占一半以上,其感染与多种消化系统疾病有关,且可产生大量的毒力因子,诱导胃肠道炎症反应、增加消化道肿瘤风险,并对胃肠道菌群产生不利影响。小肠细菌过度生长(small intestinal bacterial overgrowth,SIBO)是由小肠内细菌过多引起的表现为一系列胃肠道不适的临床综合征,其病因复杂,在肠易激综合征、炎症性肠病、肝病、胰腺炎等多种消化系统疾病中有较高的阳性率。本文针对H.pylori感染及治疗对SIBO的可能影响及其相关机制作出综述,并阐述了益生菌对于铋四联疗法根除H.pylori后肠道菌群的调节作用。目前对合并H.pylori感染及SIBO的人群治疗方案尚无定论,本文将对其治疗方案进行讨论。

奶牛产后子宫病的中西医结合疗法

胎衣不下、子宫内膜炎、子宫脱垂是奶牛产后常见的子宫疾病,临床上以胎衣滞留、子宫黏膜炎症和子宫脱出等为主要症状。这些疾病发病率高、死亡率低,严重影响奶牛生产性能和繁殖力,甚至导致奶牛被提前淘汰,造成较大经济损失。临床实践中,采用中西药结合治疗方法,可提高奶牛子宫疾病的治愈率,缩短康复时间。

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.

Small intestinal bacteria overgrowth decreases small intestinalmotility in the NASH rats

AIM: To explore the relationship between small intestinalmotility and small intestinal bacteria overgrowth(SIBO) in Nonalcoholic steatohepatitis (NASH), andto investigate the effect of SIBO on the pathogenesisof NASH in rats. The effect of cidomycin in alleviatingseverity of NASH is also studied. METHODS: Forty eight rats were randomly dividedinto NASH group (n = 16), cidomycin group (n = 16)and control group (n = 16). Then each group weresubdivided into small intestinal motility group (n = 8),bacteria group (n = 8) respectively. A semi-solid coloredmarker was used for monitoring small intestinal transit.The proximal small intestine was harvested under sterilecondition and processed for quantitation for aerobes(E. coli) and anaerobes (Lactobacilli). Liver pathologicscore was calculated to qualify the severity of hepatitis.Serum ALT, AST levels were detected to evaluate theseverity of hepatitis. RESULTS: Small intestinal transit was inhibited inNASH group (P < 0.01). Rats treated with cidomycinhad higher small intestine transit rate than rats in NASHgroup (P < 0.01). High fat diet resulted in quantitativealterations in the aerobes (E. coli ) but not in theanoerobics (Lactobacill). There was an increase in thenumber of E. coli in the proximal small intestinal florain NASH group than in control group (1.70 ± 0.12 log10(CFU/g) vs 1.28 ± 0.07 log10 (CFU/g), P < 0.01). TNF-αconcentration was significantly higher in NASH groupthan in control group (1.13 ± 0.15 mmol/L vs 0.57 ±0.09 mmol/L, P < 0.01). TNF-α concentration was lowerin cidomycin group than in NASH group (0.63 ± 0.09mmol/L vs 1.13 ± 0.15 mmol/L, P < 0.01). Treatmentwith cidomycin showed its effect by significantly loweringserum ALT, AST and TNF-α levels of NASH rats. CONCLUSION: SIBO may decrease small intestinalmovement in NASH rats. SIBO may be an importantpathogenesis of Nash. And treatment with cidomycin by mouth can alleviate the severity of NASH.

Small intestinal bacterial overgrowth in inactive Crohn's disease:Influence of thiopurine and biological treatment

AIM:To investigate the influence of thiopurines and biological drugs on the presence of small intestinal bacterial overgrowth(SIBO) in patients with inactive Crohn's disease(CD).METHODS:This was a prospective study in patients with CD in remission and without corticosteroid treatment,included consecutively from 2004 to 2010.SIBO was investigated using the hydrogen glucose breath test.RESULTS:One hundred and seven patients with CD in remission were included.Almost 58%of patients used maintenance immunosuppressant therapy and 19.6%used biological therapy.The prevalence of SIBO was16.8%.No association was observed between SIBO and the use of thiopurine Immunosuppressant(12/62patients),administration of biological drugs(2/21 patients),or with double treatment with an anti-tumor necrosis factor drugs plus thiopurine(1/13 patients).Half of the patients had symptoms that were suggestive of SIBO,though meteorism was the only symptom that was significantly associated with the presence of SIBO on univariate analysis(P<0.05).Multivariate analysis revealed that the presence of meteorism and a fistulizing pattern were associated with the presence of SIBO(P<0.05).CONCLUSION:Immunosuppressants and/or biological drugs do not induce SIBO in inactive CD.Fistulizing disease pattern and meteorism are associated with SIBO.

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.

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 blinded readers assessing the tissue in a random,coded order.The number of ICC per villus was compared among controls,Campylobacter recovered rats without small intestinal bacterial overgrowth(SIBO),and Campylobacter recovered rats with SIBO.RESULTS:Three months after recovery,27% of rats gavaged with C.jejuni had SIBO.The rats with SIBO had a lower number of DMP-ICC than controls in the jejunum and ileum.Additionally there appeared to be a density threshold of 0.12 DMP-ICC/villus that was associated with SIBO.If ileal density of DMP-ICC was < 0.12 ICC/villus,54% of rats had SIBO compared to 9% among ileal sections with > 0.12(P<0.05).If the density of ICC was < 0.12 DMP-ICC/villus in more than one location of the bowel,88% of these had SIBO compared to 6% in those who did not(P<0.001).CONCLUSION:In this post-infectious rat model,the development of SIBO appears to be associated with a reduction in DMP-ICC.Further study of this rat model might help understand the pathophysiology of postinfectious irritable bowel syndrome.

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

AIM 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.METHODS Patients 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(dephosphorylateduncarboxylated matrix Gla-protein) were quantified by ELISA and vitamin K2 intake was estimated using a food frequency questionnaire.RESULTS Thirty-nine patients were included in the study. SIBO was confirmed in 12/39(30.8%) patients who also presented with a higher concentration ofdephosphorylated-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.CONCLUSION SIBO 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.

Loss of epithelial FAM20A in mice causes amelogenesis imperfecta, tooth eruption delay and gingival overgrowth

FAM20A has been studied to a very limited extent. Mutations in human FAM20A cause amelogenesis imperfecta, gingival fibromatosis and kidney problems. It would be desirable to systemically analyse the expression of FAM20A in dental tissues and to assess the pathological changes when this molecule is specifically nullified in individual tissues. Recently, we generated mice with a Fam2OA-floxed allele containing the beta-galactosidase reporter gene. We analysed FAM20A expression in dental tissues using X-Gal staining, immunohistochemistry and in situ hybridization, which showed that the ameloblasts in the mouse mandibular first molar began to express FAM20A at 1 day after birth, and the reduced enamel epithelium in erupting molars expressed a significant level of FAM2OA. By breeding K14-Cre mice with Fam20An^x/fl^x mice, we created K14-Cre;Fam20Af/flox/flox （conditional knock out, cKO） mice, in which Fam20A was inactivated in the epithelium. We analysed the dental tissues of cKO mice using X-ray radiography： histology and immunohistochemistry. The molar enamel matrix in cKO mice was much thinner than normal and was often separated from the dentinoenamel junction. The Fam2OA-deficient ameloblasts were non-polarized and disorganized and were detached from the enamel matrix. The enamel abnormality in cKO mice was consistent with the diagnosis of amelogenesis imperfecta. The levels of enamelin and matrix metalloproteinase 20 were lower in the ameloblasts and enamel of cKO mice than the normal mice, The cKO mice had remarkable delays in the eruption of molars and hyperplasia of the gingival epithelium. The findings emphasize the essential roles of FAM20A in the development of dental and oral tissues.

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. After 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.

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.