Small intestinal bacterial overgrowth among patients with celiac disease unresponsive to a gluten free diet

Background/AimsLittle is known about the relationship between small intestinal bacterial overgrowth (SIBO) and celiac disease (CeD) in patients who are unresponsive to a gluten-free diet (GFD). This study aimed to determine the SIBO prevalence in patients with CeD who are unresponsive to a GFD.Materials and MethodsWe conducted a case-control study from July 2012 to September 2014. We included 32 patients with CeD who were unresponsive to a GFD and 52 healthy age- and sex-matched controls. Demographic, clinical, and laboratory data were obtained from patients’ medical records. Antitissue transglutaminase antibody determined by enzyme-linked immunosorbent assay was recorded, and lactulose hydrogen breath test (LHBT) was used to detect SIBO in all participants. Microbiological analysis, including jejunal aspirates obtained using upper endoscopy, was performed for only 20 patients with CeD.ResultsA total of 10 (31%) of 32 patients with CeD and 4 (7.7%) of 52 controls tested positive for LHBT, with a statistically significant difference (p=0.007). Of 20 cultures, 3 (15%) were positive with no statistically significant correlation between the cultures and LHBT (p=0.05). In a subgroup analysis of children who were 18 years old or younger, 7/24 (29.2%) patients with CeD had a positive LHBT compared with 3/32 (9.4%) controls, but this difference was not statistically significant (p=0.08).ConclusionThe prevalence of SIBO was 31% in unresponsive patients with CeD according to LHBT and 15% in the quantitative culture of the jejunal aspirate, which is comparable with the published Western literature     

Utility of hydrogen breath tests in diagnosis of small intestinal bacterial overgrowth in malabsorption syndrome and its relationship with oro-cecal transit time.

BACKGROUND: Small intestinal bacterial overgrowth (SIBO), which may result from intestinal stasis, is common in malabsorption syndrome (MAS). Quantitative culture of upper gut aspirate is used as a gold standard for the diagnosis of SIBO. Studies on diagnosis of SIBO using non-invasive hydrogen breath tests are contradictory. METHODS: 83 patients (age 35 [14-70] y; 50 men) with MAS due to various causes were investigated for SIBO using quantitative culture of upper gut aspirate obtained using a special endoscopic catheter and glucose and lactulose hydrogen breath tests (GHBT, LHBT). Sustained elevation in breath hydrogen of 12 ppm above basal and two separate peaks (one due to SIBO and the other from colon) were diagnostic of SIBO in GHBT and LHBT, respectively. Oro-cecal transit time (OCTT) was estimated using LHBT in 71 patients. RESULTS: Thirty two of 81 (39.5%) patients with MAS had SIBO on culture (>or= 10(5) CFU/mL). Using aspirate culture as the gold standard, sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of GHBT to diagnose SIBO were 44%, 80%, 62%, 67% and 65%, respectively; the corresponding values for LHBT were 31%, 86%, 62%, 54% and 55%, respectively. OCTT in patients with SIBO diagnosed on GHBT and/or aspirate culture (n=58) was longer than in those without (170 [60-250] vs. 120 [50-290] min, p=0.02); of others, 7 were hydrogen non-producers and in 6 OCTT could not be assessed due to sustained early peak because of SIBO. CONCLUSIONS: GHBT and LHBT are highly specific but insensitive for diagnosis of SIBO in MAS; OCTT is longer in patients with MAS and SIBO than in those without.     

Early hydrogen excretion peaks during breath tests. Small intestinal bacterial overgrowth or accelerated transit?

BackgroundSmall intestinal bacterial overgrowth (SIBO) has been reported with varying prevalence, depending upon the criteria used for diagnosis. Lactulose and glucose breath tests are the most used in clinical settings. Early rises of hydrogen excretion during a lactose breath test suggest SIBO, but the finding could result from accelerated mouth-to-caecum transit time.AimsDefining the prevalence of early hydrogen peaks during lactose breath tests and assessing the proportion of patients affected by SIBO.MethodsAn early (≤ 60′) hydrogen excretion peak was observed in 120/663 patients with positive lactose hydrogen breath test. Eighty-one of them underwent a 50 g-9sample-glucose hydrogen breath test to diagnose SIBO.ResultsThe glucose breath test proved positive in 11/81 (13.6%) patients. The positivity rate was 18.2% (2/11) in those with the first peak detected at 30′ and 12.8% (9/70) in those with the peak occurring at 60′.ConclusionsEarly hydrogen excretion peaks are rarely associated with SIBO. The low positive predictive value indicates that the finding does not help identifying patients at high risk for this condition. Indirectly, the present data support the opinion that the prevalence of SIBO diagnosed by standard lactulose breath tests is much lower than reported, and the reliability of the test is low.     

Small intestinal bacterial overgrowth and delayed orocecal transit time in patients with cirrhosis and low-grade hepatic encephalopathy

Background

Hepatic encephalopathy (HE) is associated with poor prognosis in cirrhosis. Gut-derived nitrogenous substances play a role in pathogenesis of HE. The present study was conducted to assess small intestinal bacterial overgrowth (SIBO) and prolonged orocecal transit time (OCTT) in cirrhosis and low-grade HE.

Methods

In cross-sectional prospective study, 75 patients were divided into 3 groups: group 1 (no HE, n = 31), group 2 (minimal HE, n = 29), and group 3 (early/grade 1 HE, n = 15). Minimal HE (MHE) was diagnosed when psychometric hepatic encephalopathy score (PHES) was ≤5. Early HE was diagnosed, according to West Haven criteria. All patients underwent glucose hydrogen breath test (GHBT) for SIBO and lactulose hydrogen breath test (LHBT) for OCTT.

Results

A total of 29 patients (38.67 %) had MHE and 15 (20 %) had early HE. Prevalence of MHE in Child–Turcotte–Pugh (CTP) class A, B, and C was 33.3, 38.71, and 45 %, respectively, while SIBO was detected in 26 (34.67 %). Prevalence of SIBO was 12.5 % in CTP class A, 41.94 % in CTP class B, and 50 % in CTP class C. Five (16.13 %) patients in no HE group had SIBO as compared to 14 (48.28 %) in MHE group and 7 (46.67 %) in early HE group (p = 0.018). OCTT was 111.13 ± 13.95 min in patients with no HE as compared to 137.59 ± 14.80 min in patients with MHE and 150 ± 15.12 min in patients with early HE (p < 0.001). OCTT was significantly prolonged in patients with SIBO (145 ± 17.49 min) than in those without SIBO (120.71 ± 18.3 min) (p < 0.001).

Conclusion

SIBO and delayed OCTT are more common with MHE and early HE in patients with cirrhosis.     

Sobrecrecimiento bacteriano del intestino delgado en pacientes con lesión medular

AimSpinal cord injury (SCI) patients may have intestinal dysmotility and digestive symptoms that are associated with small intestinal bacterial overgrowth (SIBO). The aim of this study is to describe the prevalence of SIBO in SCI patients and the risk factors of its development.MethodsTwenty-nine consecutive SCI patients were studied (10 women/19 men; mean age 47 years), 16 with subacute injuries (<9 months) and 13 with chronic injuries (>1 year). Nine patients were affected by tetraplegia and 15 by paraplegia. Each patient underwent a glucose breath test according to the North American Consensus and the presence of abdominal symptoms was evaluated during the test.The results were compared with 15 non-neurological patients with SIBO.ResultsSix patients tested positive for SIBO (21%), all of them affected by SCI in the subacute phase, 6/16 vs. 0/13 in the chronic phase (P<.05) and the majority with tetraplegia, 5/9 vs. 1/19 with paraplegia (P<.05). No statistically significant relationship was found with other clinical characteristics. All the tests were positive for methane or mixed (methane and hydrogen), while only 67% of the controls had methane-predominant production (P>.05).ConclusionSCI patients can develop SIBO, more frequently in the subacute phase and in tetraplegic patients, highlighting a high production of methane. This complication should be considered in neurogenic bowel management.     

Small intestinal bacterial overgrowth is common both among patients with alcoholic and idiopathic chronic pancreatitis

BackgroundSmall intestinal bacterial overgrowth (SIBO) is known to occur in patients with chronic pancreatitis, particularly of alcoholic etiology. There are, however, scanty data on frequency of SIBO in patients with chronic idiopathic pancreatitis and factors associated with its occurrence.Methods68 patients with chronic pancreatitis and 74 age and gender-matched healthy subjects (HS) were evaluated for SIBO using glucose hydrogen breath test (GHBT). Persistent rise in breath hydrogen 12 ppm above basal (at least two recordings) was diagnostic of SIBO.ResultSIBO was diagnosed more often among patients with chronic pancreatitis than controls (10/68 [14.7%] vs. 1/74 controls [1.3%]; p = 0.003). Of 68 patients, 22 (32.3%) had alcoholic and 46 (67.6%) had idiopathic chronic pancreatitis. SIBO was as commonly detected among patients with alcoholic as idiopathic pancreatitis (3/22 [13.6%] vs. 7/46 [15.2%]; p = 0.86). Age, gender, body mass index (BMI), steatorrhoea, pain, analgesic use, pancreatic calcifications and use of pancreatic enzyme supplements had no relationship with the presence of SIBO. Diabetes mellitus tended to be commoner among patients with chronic pancreatitis with than without SIBO (6/10 [60%] vs. 18/58 [31%]; p = 0.07).ConclusionSIBO was commoner among patients with chronic pancreatitis, both alcoholic and idiopathic, than HS. Though presence of SIBO among patients with chronic pancreatitis tended to be commoner among those with diabetes mellitus, there was no relationship with age, gender, BMI, steatorrhoea, pain, analgesic use, pancreatic calcifications and use of pancreatic enzyme supplements.     

Lactose malabsorption in the elderly: Role of small intestinal bacterial overgrowth

Objective. The prevalence of lactose malabsorption (LM) is increased in the elderly, although the mechanisms responsible are still a matter of speculation. The objective of this study was to investigate the possible roles of reduced functional small intestinal absorptive area, lactase deficiency and small intestinal bacterial overgrowth (SIBO). Material and methods. Twenty Caucasian (Anglo-Celtic), asymptomatic, well-nourished, elderly volunteers (median age 79 years, range 70–94 years) with no clinically apparent predisposition to SIBO underwent a 50 g lactose breath hydrogen test (LBHT) and mannitol absorption test, the latter as an index of functional small intestinal absorptive area. Those with LM additionally underwent bacteriological assessment of small intestinal secretions and mucosal biopsy, to assess the contribution of SIBO and lactase deficiency, respectively, to the pathogenesis of LM in individual cases. The prevalence of SIBO was also determined in elderly subjects without LM. Twenty asymptomatic younger subjects (median age 29 years, age range 18–35 years) served as controls. All subjects were “hydrogen producers” in response to lactulose. Results. LM was evident in 10/20 (50%) elderly subjects and 1/20 (5%) younger subjects (p=0.003). Mannitol absorption did not differ significantly in elderly and younger subjects or in elderly subjects with and without LM. SIBO was documented in 9/10 (90%) elderly subjects with LM; eradication was associated with resolution of LM. Lactase deficiency was evident in only one elderly subject with LM. SIBO was evident in 2/10 (20%) elderly subjects without LM (p=0.005 compared to those with LM). Lactulose breath hydrogen test identified only 2/11 (18%) elderly subjects with SIBO. Conclusions. Increased prevalence of LM in the elderly is mostly due to clinically non-apparent SIBO, rather than mucosal factors. The lactulose breath hydrogen test cannot be relied upon to identify elderly subjects with SIBO, even in those without an anatomical predisposition.     

Milk is a useful test meal for measurement of small bowel transit time

To improve and standardize the measurement of small bowel transit time, milk was employed for the test meal instead of the conventional lactulose meal. Although 92% of the subjects were lactase deficient, only 2% were milk intolerant and 13% were lactose intolerant. Small bowel transit time with milk (milk breath hydrogen test) was 113±9 min (mean ± SE,n=20); the normal range calculated from the mean ±2 SD was 31–195 min. The coefficient of variation in the milk hydrogen breath test was 13 ± 4% (n=6), whereas in the lactulose hydrogen breath test, it was 39±16% (n=10). The frequency of non-hydrogen producers, the occurrence of discomfort, and the reproducibility were better, though not significantly so, in the milk hydrogen breath test than in the lactulose. Since lactase activity in the intestine is variable in lactase-deficient subjects, small bowel transit times for milk may change from subject to subject. However, individual reproducibility of the milk hydrogen breath test is good. It could be useful for pharmacological experiments using paired comparison, for screening tests, or for the follow up of diseases in which small bowel transit time is affected.     

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

BACKGROUNDGut 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.AIMTo study the relationship of gut dysbiosis and SIBO in cirrhosis.METHODSThis observational study included 47 in-patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. SIBO was assessed using the lactulose hydrogen breath test.RESULTSSIBO 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.CONCLUSIONDespite 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.     

Irritable Bowel Syndrome,Particularly the Constipation-Predominant Form,Involves an Increase in Methanobrevibacter smithii,Which Is Associated with Higher Methane Production

Background/AimsBecause Methanobrevibacter smithii produces methane, delaying gut transit, we evaluated M. smithii loads in irritable bowel syndrome (IBS) patients and healthy controls (HC).MethodsQuantitative real-time polymerase chain reaction for M. smithii was performed on the feces of 47 IBS patients (Rome III) and 30 HC. On the lactulose hydrogen breath test (LHBT, done for 25 IBS patients), a fasting methane result ≥10 ppm using 10 g of lactulose defined methane-producers.ResultsOf 47, 20 had constipation (IBS-C), 20 had diarrhea (IBS-D) and seven were not sub-typed. The M. smithii copy number was higher among IBS patients than HC (Log₁₀5.4, interquartile range [IQR; 3.2 to 6.3] vs 1.9 [0.0 to 3.4], p<0.001), particularly among IBS-C compared to IBS-D patients (Log₁₀6.1 [5.5 to 6.6] vs 3.4 [0.6 to 5.7], p=0.001); the copy number negatively correlated with the stool frequency (R=−0.420, p=0.003). The M. smithii copy number was higher among methane-producers than nonproducers (Log₁₀6.4, IQR [5.7 to 7.4] vs 4.1 [1.8 to 5.8], p=0.001). Using a receiver operating characteristic curve, the best cutoff for M. smithii among methane producers was Log₁₀6.0 (sensitivity, 64%; specificity, 86%; area under curve [AUC], 0.896). The AUC for breath methane correlated with the M. smithii copy number among methane producers (r=0.74, p=0.008). Abdominal bloating was more common among methane producers (n=9/11 [82%] vs 5/14 [36%], p=0.021).ConclusionsPatients with IBS, particularly IBS-C, had higher copy numbers of M. smithii than HC. On LHBT, breath methane levels correlated with M. smithii loads.     

三种常见回肠末端溃疡性病变小肠细菌过度生长情况的研究

目的 探讨克罗恩病、肠结核、淋巴瘤三种常见回肠末端溃疡性病变小肠细菌过生长（SIBO）的情况.方法 选择近5年在我院首次住院确诊的,且内镜下仅回肠末端或合并回盲部、回盲瓣存在溃疡性病变的克罗恩病组、肠结核组、淋巴瘤组三组患者,治疗前通过葡萄糖氢呼气试验（GHBT）分别检测其SIBO情况,并与健康对照组进行组间比较分析.结果 三组回肠末端溃疡性病变患者与健康对照组的SIBO阳性率及试餐后呼气氢浓度比较均有显著差异（P＜0.01）.肠结核组患者的SIBO阳性率及试餐后呼气氢浓度较克罗恩病组和淋巴瘤组明显增高,差异有显著性（P＜0.05）.结论 回肠末端溃疡性病变患者容易发生SIBO,特别是肠结核患者尤为明显,通过呼气氢浓度检测,有利于针对性地进行下一步诊治.     

Lower frequency of MMC is found in IBS subjects with abnormal lactulose breath test,suggesting bacterial overgrowth

We have recently described an association between irritable bowel syndrome (IBS) and abnormal lactulose breath test, suggesting small intestinal bacterial overgrowth (SIBO). However, the mechanism by which SIBO develops in IBS is unknown. In this case–control study we evaluate the role of small intestinal motility in subjects with IBS and SIBO. Small intestinal motility was studied in consecutive IBS subjects with SIBO on lactulose breath test. After fluoroscopic placement of an eight-channel water-perfused manometry catheter, 4-hr fasting recordings were obtained. Based on this, the number and duration of phase III was compared to 30 control subjects. To test whether there was a relationship between the motility abnormalities seen and the SIBO status of the patient at the time of the motility, subjects with a breath test within 5 days of the antroduodenal manometry were also compared. Sixty-eight subjects with IBS and SIBO were compared to controls. The number of phase III events was 0.7 ± 0.8 in IBS subjects and 2.2 ± 1.0 in controls (P < 0.000001). The duration of phase III was 305 ± 123 sec in IBS subjects and 428 ± 173 in controls (P < 0.001). Subjects whose SIBO was still present at the time of manometry had less frequent phase III events than subjects with eradicated overgrowth (P < 0.05). In conclusion, phase III is reduced in subjects with IBS and SIBO. Eradication of bacterial overgrowth seems to result in some normalization of motility.     

Hydrogen- and Methane-Based Breath Testing and Outcomes in Patients With Heart Failure

BackgroundRecent evidence endorses gut microbiota dysregulation in the pathophysiology of heart failure (HF). Small intestinal bacterial overgrowth (SIBO) might be present in HF and associated with poor clinical outcomes. Lactulose breath testing is a simple noninvasive test that has been advocated as a reliable indicator of SIBO. In patients with HF, we aimed to evaluate the association with clinical outcomes of the exhaled hydrogen (H₂) and methane (CH₄) concentrations through the lactulose breath test.Methods and ResultsWe included 102 patients with HF in which lactulose SIBO breath tests were assessed. Cumulative gas was quantified by the area under the receiver operating characteristic curve of CH₄ (AUC-CH₄) and H₂ (AUC-H₂). Clinical end points included the composite of all-cause death with either all-cause or HF hospitalizations, recurrent all-cause hospitalizations, and recurrent HF hospitalizations. Medians (interquartile ranges) of AUC-H₂ and AUC-CH₄ were 1290 U (520-2430) and 985 U (450-2120), respectively. In multivariable analysis, AUC-H₂ (per 1000 U) was associated with all-cause death/all-cause hospitalization (hazard ratio [HR] 1.21, 95% CI 1.04–1.40; P = .012), all-cause death/HF hospitalization (HR 1.20, 95% CI 1.03–1.40; P = .021), and an increase in the rate of recurrent all-cause (incidence rate ratio [IRR] 1.31, 95% CI 1.14–1.51; P < .001) and HF (IRR 1.41, 95% CI 1.15–1.72; P = .001) hospitalizations. AUC-CH₄ was not associated with any of these end points.ConclusionsAUC-H₂, a safe and noninvasive method for SIBO estimation, is associated with higher risk of long-term adverse clinical events in patients with HF. In contrast, AUC-CH₄ did not show any prognostic value.     

Four-sample lactose hydrogen breath test for diagnosis of lactose malabsorption in irritable bowel syndrome patients with diarrhea

AIM: To validate 4-sample lactose hydrogen breath testing (4SLHBT) compared to standard 13-sample LHBT in the clinical setting.METHODS: Irritable bowel syndrome patients with diarrhea (IBS-D) and healthy volunteers (HVs) were enrolled and received a 10 g, 20 g, or 40 g dose lactose hydrogen breath test (LHBT) in a randomized, double-blinded, controlled trial. The lactase gene promoter region was sequenced. Breath samples and symptoms were acquired at baseline and every 15 min for 3 h (13 measurements). The detection rates of lactose malabsorption (LM) and lactose intolerance (LI) for a 4SLHBT that acquired four measurements at 0, 90, 120, and 180 min from the same data set were compared with the results of standard LHBT.RESULTS: Sixty IBS-D patients and 60 HVs were studied. The genotype in all participants was C/C-13910. LM and LI detection rates increased with lactose dose from 10 g, 20 g to 40 g in both groups (P < 0.001). 4SLHBT showed excellent diagnostic concordance with standard LHBT (97%-100%, Kappa​​ 0.815-0.942) with high sensitivity (90%-100%) and specificity (100%) at all three lactose doses in both groups.CONCLUSION: Reducing the number of measurements from 13 to 4 samples did not significantly impact on the accuracy of LHBT in health and IBS-D. 4SLHBT is a valid test for assessment of LM and LI in clinical practice.     

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.     

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.     

Frequency and Factors Associated with Small Intestinal Bacterial Overgrowth in Patients with Cirrhosis of the Liver and Extra Hepatic Portal Venous Obstruction

Spontaneous bacterial peritonitis (SBP), a common complication of cirrhosis of liver, might result from translocation of bacteria from the small bowel. However, there is scanty data on frequency of small intestinal bacterial overgrowth (SIBO) in patients with cirrhosis of the liver. There are no data on SIBO in patients with extra-hepatic portal venous obstruction (EHPVO) in the literature. A total of 174 patients with cirrhosis of the liver, 28 with EHPVO and 51 healthy controls were studied for SIBO using glucose hydrogen breath test (GHBT). Persistent rise in breath hydrogen 12 ppm above basal (at least two readings) was considered diagnostic of SIBO. Of 174 patients (age 47.2 ± 11.9 years, 80.5% male) with cirrhosis due to various causes, 67 (38.5%) were in Child’s class A, 70 (40.2%) class B and 37 (21.7%) class C. Of the 174 patients with cirrhosis, 42 (24.14%) had SIBO as compared to 1 of 51 (1.9%) healthy controls (P < 0.0001). Patients with EHPVO had similar frequency of SIBO compared to healthy controls [2/28 (7.14%) vs 1/51 (1.97%), P = ns]. Frequency of SIBO in Child’s A, B and C was comparable [13 (18.6%) vs 16 (23.9%) and 13 (35.1%), respectively; P = ns]. Presence of SIBO were not related to ascites, etiology of cirrhosis, and degree of liver dysfunction. SIBO is common in patients with cirrhosis of the liver. Patients with EHPVO do not have higher frequency of SIBO than healthy subjects. SIBO in cirrhosis is not related to the degree of derangement in liver function or of portal hypertension.     

Detection of bacterial overgrowth in IBS using the lactulose H2 breath test: comparison with 14C-D-xylose and healthy controls

OBJECTIVES Recent reports suggest bacterial overgrowth is commonly associated with irritable bowel syndrome (IBS) when diagnosed using the lactulose hydrogen breath test (LHBT). We employed this test to examine whether similar findings exist in a geographically distinct population of Rome II positive IBS patients and compared it to the 14C-D-xylose breath test, a test with acknowledged greater specificity for bacterial overgrowth. METHODS: In the first series, Rome II IBS patients underwent a 10 g lactulose breath test and a standardized 1 g 14C-D-xylose breath test and answered IBS symptom questionnaires. A positive test required an elevated breath hydrogen concentration within 90 min, two distinct peaks, and an increase >20 ppm. In a second series, control patients lacking gastrointestinal symptoms underwent a lactulose breath test. A positive test required an elevation of breath hydrogen >20 ppm within 90 or 180 min. These criteria were also applied to lactulose breath tests from IBS cases in series one. RESULTS: The IBS patients were predominantly female (64%) and most reported severe symptoms (80%). The majority had diarrhea predominant symptoms (63%) and only 3% were constipation predominant. In the first series, only 10% of patients had a positive lactulose breath test and 13% had a positive 14C-D-xylose test. In the second series, the number of abnormal LHBTs was much higher but no differences were found between IBS patients and controls. CONCLUSION: The lactulose breath test did not reliably detect a common association between bacterial overgrowth and IBS in our patient population.     

Lactulose hydrogen breath test in orocecal transit assessment

Orocecal transit time can be studied easily using the hydrogen breath test with lactulose, but the method has some important limitations. The orocecal transit time of 10 patients suffering from irritable bowel syndrome was measured twice, at a one-week interval, by breath test and scintigraphy simultaneously using an aqueous solution of 20 g lactulose containing 74 MBq of [^99mTc]DTPA. Abdominal radioactivity and alveolar hydrogen values obtained every 5 min were noted and used to obtain the following: orocecal transit time by the two methods; ileocecal lactulose flow; total and per gram of lactulose hydrogen production; mean hydrogen concentration during the right colon filling; and measurement error of the breath test with respect to the scintigraphy. In the case of the breath test, the orocecal transit time intrapatient reproducibility was better (coefficient of variation =13.5%) when a hydrogen threshold increment of 5 ppm was used; the best correlation with the scintigraphic measurement was observed at this threshold (r=0.90,P<0.001). The breath test overestimated orocecal transit time with the error correlating negatively and significantly with the total hydrogen production and, particularly, the mean hydrogen concentration (r=0.79,P<0.01): for a mean hydrogen concentration of more than 15 ppm, the error was negligible, while within this value there was a noticeable overestimation. To conclude, the lactulose hydrogen breath test is capable of giving an accurate measurement of orocecal transit time if a hydrogen threshold increment of 5 ppm is chosen and if the mean hydrogen concentration in the first 30 min of the right colon filling is taken into account.     

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 was 16.8%. No association was observed between SIBO and the use of thiopurine Immunosuppressant (12/62 patients), 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.