Glucose Breath Test Research Articles

Gastrointestinal Motility and Response to Levodopa in Parkinson's Disease: A Proof-of-Concept Study.

Simultaneous measurement of gastrointestinal transit time (GITT) and plasma levodopa concentration (PLC) is crucial to understanding the effect of dysfunctional motility on levodopa response in patients with Parkinson's disease (PwPD). The aim is to determine if altered segmental GITT correlates with clinical response and PLC variability in PwPD. Ten typical and 10 erratic responders ingested the SmartPill (SP) wireless motility capsule. Serial PLC and finger tapping, obtained every 30minutes for 3 hours after SP/levodopa ingestion, evaluated the correlation between GITT, clinical response, and PLC. Glucose breath testing assessed small intestinal bacterial overgrowth (SIBO). GITT was not significantly different in "typical" and "erratic" responders. SIBO was positive in half of the erratic and negative in most typical responders. SP is a feasible technology for assessing GITT in PwPD. A larger study may be able to significantly differentiate/correlate GITT in different segments of the GI tract with response to levodopa. © 2022 International Parkinson and Movement Disorder Society.

Changes in Glucose Breath Test in Cystic Fibrosis Patients Treated With 1 Month of Lumacaftor/Ivacaftor.

Alteration of the airway microbiota is a hallmark of cystic fibrosis (CF) pulmonary disease. Dysfunction of cystic fibrosis transmembrane regulator (CFTR) in the intestine also promotes changes in local microbiota such as small intestinal bacterial overgrowth (SIBO), which is common in CF. We evaluated whether therapy with the CFTR modulator combination lumacaftor/ivacaftor (luma/iva) has a beneficial impact on SIBO as measured by breath testing (BT). A multicenter longitudinal study of CFTR-dependent disease profiling (NCT02477319) included a prospective evaluation for SIBO by BT. Tidal breath samples were collected after fasting and 15, 30, 45, 60, 90, and 120 minutes after ingestion of glucose, before and 1 month after subjects initiated luma + iva. Forty-two subjects enrolled in the sub-study (mean age = 23.3 years; 51% female; 9.5% Latinx); 38 completed a hydrogen BT at both time points, of which 73.7% had a positive BT before luma/iva (baseline) and 65.8% had a positive test after luma/iva ( P = 0.44); shifts from negative to positive were also seen. Use of azithromycin (63.1%) and inhaled antibiotics (60.5%) were not associated with positive BT. Acid-blocking medications were taken by 73% of those with a negative BT at baseline and by 35% with a positive baseline BT ( P = 0.04). We found a high rate of positive hydrogen breath tests in individuals with CF, confirming that SIBO is common. One month of luma/iva did not significantly change the proportion of those with positive breath hydrogen measurements.

Serum Pepsinogen and Gastrin Levels: Reliable Markers to Predict Small Intestinal Bacterial Overgrowth.

Serum pepsinogen, a useful indicator of gastric acidity, could reflect small intestinal bacterial overgrowth. The aim of this study is to evaluate the relationship between small intestinal bacterial overgrowth and profiles including pepsinogen or gastrin. We conducted a prospective study with 62 patients with a functional gastrointestinal disorder. All patients underwent glucose breath test for small intestinal bacterial overgrowth, immediately followed by upper endoscopy to survey gastric injury and Campylobacter-like organism test for Helicobacter pylori and serum laboratory tests including gastrin, pepsinogen I and II. The positivity to small intestinal bacterial overgrowth was 17.7%. Significantly, low total hydrogen concentration during a glucose breath test, low prevalence for gastric injury, and high H. pylori positivity rate were shown in groups with pepsinogen I/II ratio ≤ 3.5 compared to those with pepsinogen I/II ratio > 3.5 or in groups with serum gastrin > 35.4 pg/mL comparing to those with serum ≤ 35.4 pg/mL, respectively. A high gastrin level was independently associated with H. pylori infection. A proportionally correlated tendency between pepsinogen I/II ratio and total hydrogen concentration was shown, whereas that of inverse proportion between H2 and gastrin was observed. Old age was solely independent predicting factor for small intestinal bacterial overgrowth (P = .03) in the multivariate analysis. Old age was significantly related to the presence of small intestinal bacterial overgrowth in functional gastrointestinal disorder patients. Although pepsinogen and small intestinal bacterial overgrowth seem irrelevant, elevated gastrin level may cautiously indicate a decreased breath hydrogen concentration. Further studies should consider the function of intestinal motility and gastric acidity in patients with hydrogen-producing small intestinal bacterial overgrowth.

Role of Glucose Breath Test for Small Intestinal Bacterial Overgrowth in Children and Adolescents With Functional Abdominal Pain Disorders in Korea.

Background/AimsSmall intestinal bacterial overgrowth (SIBO) is expected in children and adolescents with functional abdominal pain disorders (FAPDs). This study is conducted to estimate the prevalence of SIBO and to investigate the role of SIBO in children and adolescents with FAPDs.MethodsThis prospective study enrolled children with FAPDs fulfilling the Rome IV criteria. A hydrogen-methane glucose breath test was used to diagnose SIBO. A survey of bowel symptoms using questionnaires, birth history, types of feeding, and the presence of allergy was conducted.ResultsSixty-eight children and adolescents (range, 6-17 years; median, 12.5 years) were enrolled. SIBO was detected in 14 patients (20.6%). Age (≥ 12 years) (P < 0.003) and loose stool (P = 0.048) were significantly more common in children with SIBO than in children without SIBO. However, the history of allergies (P = 0.031) was less common in children with SIBO than those without SIBO. No significant differences were observed in other demographic findings. In multivariate analysis, age (≥ 12 years) was the independent factor predicting SIBO in children with FAPDs.ConclusionsSIBO is not uncommon in children and adolescents with FAPDs. Among children aged above 12 years and diagnosed with FAPDs, SIBO is a suspected clinical target for treatment to relieve intestinal symptoms. A further study to investigate the association between intestinal bacteria and history of allergy is needed.

The prevalence of small intestinal bacterial overgrowth in diabetes mellitus: a systematic review and meta-analysis.

Objective: We conducted this systematic review and meta-analysis to estimate the prevalence of SIBO in diabetic patients and to determine the association between SIBO and diabetes.Methods: A comprehensive literature search of the PubMed, Cochrane Library and EMBASE databases from inception to June 2021 was conducted for studies correlating SIBO with diabetes. Studies were screened, and relevant data were extracted and analysed. The pooled prevalence of SIBO among diabetic patients and the odds ratio of SIBO among diabetic patients compared with controls were calculated.Results: Fourteen studies including 1417 diabetic patients and 649 controls met the inclusion criteria. The pooled prevalence of SIBO in diabetes was 29% (95% CI 20–39%). The odds ratio of SIBO in diabetic patients was 2.91 (95% CI 0.82–10.32, p=0.1) compared with controls. Subgroup analyses showed that the prevalence of SIBO in diabetes was higher in studies using jejunal aspirate culture for diagnosis (39%, 95% CI 12–66%) than in those using the lactulose breath test (31%, 95% CI 18–43%) or glucose breath test (29%, 95% CI 14–43%). The prevalence of SIBO in diabetes was higher in studies conducted in Western countries (35%, 95% CI 21–49%) than in those conducted in Eastern countries (24%, 95% CI 14–34%), and the prevalence of SIBO in type 1 diabetes (25%, 95% CI 14%–36%) was not significantly different from that in type 2 diabetes (30%, 95% CI 13%–47%).Conclusions: Twenty-nine percent of diabetic patients tested positive for SIBO, and the risk of SIBO in diabetic patients was 2.91 times higher than that in patients without diabetes. Diabetes could be a predisposing factor for the development of SIBO, especially among patients diagnosed by jejunal aspirate culture or those in Western populations.

A Single Fasting Exhaled Methane Level Correlates With Fecal Methanogen Load, Clinical Symptoms and Accurately Detects Intestinal Methanogen Overgrowth.

A 2-hour breath test is the gold standard for diagnosing intestinal methanogen overgrowth (IMO). This method can be cumbersome especially if used repetitively to monitor treatment response. Therefore, we aimed to assess the reliability of a fasting single methane measurement (SMM) in diagnosing IMO and its utility as a biomarker to monitor treatment response in subjects with IMO. First, we calculated the test characteristics of SMM compared with lactulose and glucose breath test in 2 large-scale retrospective cohorts. Second, the symptomology associated with SMM using various cutoffs was analyzed. Third, in a double-blind randomized control trial, the temporal stability of SMM levels in subjects taking placebo was analyzed. Fourth, stool Methanobrevibacter smithii loads were quantified using quantitative polymerase chain reaction and compared with SMM levels. Last, the change in SMM over time during antibiotic therapy was analyzed. Using the cutoff of SMM ≥10 ppm, SMM had a sensitivity of 86.4% and specificity of 100% for diagnosing IMO on the glucose and lactulose breath tests and was associated with constipation (5.65 ± 3.47 vs 4.32 ± 3.62, P = 0.008). SMM remained stable for 14 weeks without treatment (P = 0.45), and antibiotics lead to a decrease in SMM after 2 days (P < 0.0001). SMM was positively associate with stool M. smithii load (R = 0.65, P < 0.0001). Fasting SMM ≥10 ppm seems to accurately diagnose IMO, is associated with constipation, and correlates with stool M. smithii. SMM seems to be stable without treatment and decreases after antibiotics. SMM may be a useful test to diagnose IMO and monitor treatment response.

Chronic Intestinal Pseudo-Obstruction Is Associated with Intestinal Methanogen Overgrowth.

Chronic intestinal pseudo-obstruction (CIP) is a rare motility disorder characterized by dilated small bowel in the absence of mechanical obstruction. CIP has a known association with small intestinal bacterial overgrowth (SIBO); however, data regarding association with specific subtypes such as methane-positive (M+) and hydrogen-positive (H+) SIBO are limited. Therefore, we conducted this study to characterize subtypes of SIBO in CIP and compare them with non-CIP patients. The aim is to explore the association and prevalence of hydrogen and methane subtypes of SIBO in patients with CIP. A retrospective chart review was conducted for 494 patients who underwent glucose breath tests (GBT) in 2019. CIP was diagnosed based on clinical suspicion and after ruling out mechanical obstruction. We also reviewed demographic data, including age, gender, body mass index, tobacco and alcohol history, medical comorbidities, use of proton pump inhibitors, and history of colectomy. Among 494 patients, 7.7% (38) had CIP. The prevalence of M+ GBT in CIP patients was higher compared with non-CIP patients, and it was significant [52.6% (20/38) versus 11.8% (54/456), p < 0.001]. The prevalence of H+ GBT in our cohort of CIP patients was similar to that of non-CIP patients [23.7% (9/38) versus 25.7% (117/456), p = 0.941]. The prevalence of methane-positive GBT was higher in CIP patients than in patients without CIP. This finding further strengthens the hypothesis that the relationship between motility disorders and methanogen overgrowth is facilitative.

Relationship between untreated obstructive sleep apnea and breath hydrogen and methane after glucose load.

Patients with sleep disturbances have gastrointestinal symptoms. Breath hydrogen (H2) and methane (CH4) indicating small intestinal bacterial overgrowth (SIBO) might be related with these symptoms. The study was conducted to assess the link between breath profiles and untreated obstructive sleep apnea (OSA). : This prospective study enrolled consecutive patients with OSA using polysomnography. Heart rate variability (HRV) was used as a measurement for the balance of autonomic nervous system during polysomnography. Glucose breath test (GBT) to evaluate breath H2 and CH4 and bowel symptom questionnaire to investigate associated intestinal symptoms were performed. Among 52 patients with OSA, 16 (30.8%) showed positivity to GBT. Although no significant difference was shown in GBT positivity between patients with healthy controls and patients with OSA (13.3% vs 30.8%, P = 0.109), breath H2 and CH4 levels in the OSA group were significantly higher than those in controls (P < 0.05). Flatulence was significantly common in OSA groups with GBT positivity than those without GBT positivity. Multivariate analysis demonstrated that waist-to-hip ratio (odds ratio = 12.889; 95% confidence interval (CI): 1.257-132.200; P = 0.031) and low-to-high-frequency ratio of HRV (odds ratio = 1.476; 95% CI: 1.013-2.151, P = 0.042) are independently related to GBT positivity in patients with OSA. : Elevated breath H2 or CH4 after glucose load might not be an uncommon finding in patients with untreated OSA. Abdominal obesity and autonomic imbalance dysfunction are significantly associated with GBT positivity in OSA patients. SIBO could be considered as target for therapeutic management in OSA patients.

S3279 Diagnostic Yield of Duodenal Aspirates/Culture for SIBO or SIFO Among Patients With Cystic Fibrosis

Introduction: Cystic fibrosis (CF) is a debilitating autosomal recessive multisystem disorder involving the gastrointestinal (GI) tract. CF patients are predisposed to developing small intestinal bacterial overgrowth (SIBO) or fungal overgrowth (SIFO) secondary to altered gut motility and mucus accumulation in the small intestine. To date, there has been little systemic study of SIBO/SIFO among cystic fibrosis patients using the gold standard test of duodenal aspirates/culture for its diagnosis. We aimed to determine the diagnostic yield of duodenal aspirates in the diagnosis of SIBO/SIFO among CF patients with GI symptoms. Methods: This was a retrospective analysis of CF patients referred to our tertiary care enter with unexplained GI symptoms of more than 1 year from January 2017 to May 2021 and suspected to have SIBO/SIFO. These patients underwent endoscopy with duodenal aspirates (aerobic, anaerobic and fungal cultures) using a 3mm Liguory catheter under aseptic conditions using the Rao technique (Videogie;https://doi.org/10.1016/j.vgie.2020.11.008). A colony count of >103 CFU/mL was determined to be diagnostic for SIBO or SIFO. Results: Twelve patients (male/female = 6/6) were included in this study and 6 of whom (50%) tested positive for either SIBO or SIFO on the duodenal aspirates. Three patients (50%) had both SIBO and SIFO, 1 (17%) had SIBO only and 2 (33%) had SIFO only. Streptococcus, Rothia, Klebsiella, Methicillin-Resistant Staphylococcus Aureus, Escherichia coli, Lactobacillus, multiple anaerobes, Candida albicans and Cryptococcus not neoformans were cultured (Table). There were no significant differences in the comorbidities (diabetes, gastroparesis, constipation) and proton pump inhibitor use among CF patients with positive and negative duodenal aspirates. Conclusion: In this pilot study, we found a higher diagnostic yield for identifying SIBO/SIFO among CF patients with GI symptoms utilizing duodenal aspirates/culture. The diagnostic yield of 50% is higher than the yield of glucose breath testing for diagnosing SIBO in the literature that ranges from 31-37%. Given the risk of multidrug resistant organisms among CF patients owing to the use of multiple antibiotics for recurring pulmonary infections, the use of duodenal aspirates/culture and sensitivity could not only provide an accurate diagnosis of SIBO/SIFO but also facilitate the tailoring of treatment regimens based on antibiotic and antifungal susceptibility.Table 1.: Demographic Characteristics of the Study Population and Microbial Culture Results of the Duodenal Aspirates Abbreviations: SIBO- small intestinal bacterial overgrowth, SIFO- small intestinal fungal overgrowth, BMI- body mass index, MRSA- Methicillin-resistant Staphylococcus aureus.

Distinctive Clinical Correlates of Small Intestinal Bacterial Overgrowth with Methanogens

Most patients with small intestinal bacterial overgrowth (SIBO) produce hydrogen by fermentation of dietary carbohydrates; however, ∼30% of patients with SIBO are colonized with Archaea, anaerobic organisms that produce methane. SIBO is associated with a plethora of symptoms and conditions, but their diagnostic significance is unclear. We aimed to determine if specific symptoms and conditions are associated with methanogenic SIBO. This study received institutional review board approval (IRB00059873). In this retrospective cross-sectional study, we queried a database of glucose breath tests conducted for suspected SIBO at our tertiary care medical center, which included data on the presence or absence of gastrointestinal symptoms and conditions often associated with SIBO. All patients had undergone a standardized breath testing protocol. In a cohort of 1461 patients, 33.1% were SIBO positive; of these, 49.8% produced only hydrogen, 38.8% produced only methane, and 11.4% produced both gases. The following factors distinguished patients with hydrogen-producing SIBO, but not methanogenic SIBO, from SIBO-negative patients: vitamin B12 deficiency (odds ratio, 1.44; confidence interval [CI], 1.01-2.06; P= .046), Roux-en-Y gastric bypass (odds ratio, 2.14; CI, 1.09-4.18; P= .027), cholecystectomy (odds ratio, 1.42; CI, 1.06-1.91; P= .020), and diabetes (odds ratio, 1.59; CI, 1.13-2.24; P= .008). The absence of vitamin B12 deficiency was the sole discriminating factor between methanogenic and hydrogenic SIBO (odds ratio, 0.57; CI, 0.34-0.97; P= .038). Patients with SIBO caused by methane-producing Archaea display a different spectrum of associated symptoms and clinical conditions compared with patients with SIBO caused by hydrogen-producing bacteria, particularly a lower incidence of vitamin B12 deficiency.

Small Intestinal Bacterial Overgrowth In Various Functional Gastrointestinal Disorders: A Case-Control Study.

Small intestinal bacterial overgrowth (SIBO) is prevalent in irritable bowel syndrome (IBS), but its' association with other functional gastrointestinal disorders (FGIDs) is less certain. This study aimed to explore SIBO in a multi-racial Asian population with various FGIDs compared to non-FGID controls. Consecutive Asian adults with Rome III diagnosed common FGIDs (functional dyspepsia/FD, IBS and functional constipation/FC) and non-FGID controls were subjected to glucose breath testing, with hydrogen (H2) and methane (CH4) levels determined. A total of 244 participants (FGIDs n = 186, controls n = 58, median age 45years, males 36%, Malay ethnicity 76%) were recruited. FGIDs had a higher prevalence trend of SIBO compared to controls (16% FGIDs vs. 10% controls, p = 0.278) with 14% in FD, 18% in IBS and 17% in FC. Compared to controls, SIBO was associated with diarrhoea-predominant IBS (IBS-D) (24% vs. 10%, P = 0.050) but not with other types of FGIDs. IBS-D remained an independent predictor of SIBO (OR = 2.864, 95% CI 1.160-7.071, p = 0.023) but not PPI usage nor history of diabetes (both p > 0.050) at multivariate analysis. Compared to controls, SIBO in IBS-D was associated with an elevated H2 level (≥ 20ppm from baseline) (18% vs. 3%, p = 0.017), but not CH4 levels (≥ 10ppm) (9% vs. 7%, p = 0.493). In addition, no difference was found in the prevalence of methane-positive SIBO between chronic constipation (constipation-predominant IBS and FC) compared to controls (9% vs. 7%, P = 0.466). SIBO is prevalent amongst multi-ethnic Asian adults with and without FGIDs. Amongst various FGIDs, only IBS-D is significantly associated with SIBO.

Concomitant Irritable Bowel Syndrome Does Not Influence the Response to Antimicrobial Therapy in Patients with Functional Dyspepsia

Antimicrobial therapy improves symptoms in patients with irritable bowel syndrome (IBS), but the efficacy in functional dyspepsia (FD) is largely unknown. While FD and IBS frequently overlap, it is unknown if concomitant IBS in FD alters the response to antimicrobial therapy in FD. Thus, we aimed to assess and compare the effect of antimicrobial therapy on visceral sensory function and symptom improvement in FD patients with and without IBS. Adult patients with FD with or without IBS received rifaximin 550mg BD for 10days, followed by a 6-week follow-up period. The total gastrointestinal symptom score as measured by the SAGIS (Structured Assessment of Gastrointestinal Symptoms) questionnaire and subscores (dyspepsia, diarrhea, and constipation), symptom response to a standardized nutrient challenge and normalization of the glucose breath tests were measured. Twenty-one consecutive adult patients with FD and 14/21 with concomitant IBS were recruited. Treatment with rifaximin resulted in a significant (p = 0.017) improvement in the total SAGIS score from 34.7 (± 15.4) at baseline to 26.0 (± 16.8) at 2 weeks and 25.6 (± 17.8) at 6 weeks post-treatment. Similarly, compared to baseline there was a statistically significant improvement in SAGIS subscores for dyspepsia and diarrhea (all p < 0.05) and effects persisted for 6 weeks post-treatment. Similarly, the symptom score (and subscores) following a standardized nutrient challenge improved significantly (p < 0.001) 2 weeks post-treatment. The presence of concomitant IBS did not significantly influence the improvement of symptoms after antibiotic therapy (all p > 0.5). In FD patients, the response to antimicrobial therapy with rifaximin is not influenced by concomitant IBS symptoms.

The effectiveness of rotating versus single course antibiotics for small intestinal bacterial overgrowth.

BackgroundSmall intestinal bacterial overgrowth treatment is usually based on antibiotics with no guidelines available.ObjectiveThis study aimed to investigate the efficacy of different antibiotics to treat small intestinal bacterial overgrowth.MethodsConsecutive patients referred to our tertiary center and diagnosed with intestinal bacterial overgrowth were retrospectively included. Patients were diagnosed using a 75 g glucose breath test. Patients were treated either with a single antibiotic (quinolone or azole) or rotating antibiotics (quinolone and azole, one after the other) for 10 consecutive days per month for 3 months. A negative glucose breath test after antibiotic treatment was considered as remission. Quality of life (GIQLI) and gastrointestinal severity (IBS‐SSS) were assessed before and after antibiotic treatment. Symptomatic evaluation was realized in simple blind of glucose breath test result: patients were unaware of their results.ResultsBetween August 2005 and February 2020, 223 patients were included in the analysis (female 79.8%, mean age 50.2 ± 15.7 years). Remission was observed in 119 patients (53.4%) after one course of antibiotics and was more frequent in patients receiving rotating antibiotics than in patients receiving a single antibiotic (70.0% vs. 50.8%, p = 0.050). Remission was associated with a significant improvement in quality of life (p = 0.035) and in bloating (p = 0.004).ConclusionIn this study, the treatment of small intestinal bacterial overgrowth using rotating antibiotics was more effective than treatment using a single course of antibiotic. Remission was associated with improvement in both quality of life and bloating.

Small Intestinal Bacterial Overgrowth in Functional Dyspepsia: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis aimed to determine the role of small intestinal bacterial overgrowth (SIBO) in patients with functional dyspepsia (FD). Electronic databases were searched until July 2020 for studies reporting prevalence of SIBO in FD. The prevalence rates, odds ratio, and 95% confidence intervals (CIs) of SIBO in FD and controls were calculated. Seven studies with 263 patients with FD and 84 controls were identified. The odds for SIBO in patients with FD were significantly higher as compared to that in controls (odds ratio = 4.3, 95% CI, 1.1-17.5, 4 studies, 234 participants); however, there was moderate heterogeneity in this analysis. Including high-quality, case-control studies (all using glucose breath tests [GBTs]), the risk of SIBO in patients with FD as compared to controls was 2.8 higher (95% CI 0.8-10.0, 3 studies, 200 participants) with minimal heterogeneity in this analysis. Using the lactulose breath test, SIBO prevalence in FD was significantly higher (53.4%, 95% CI 33.9-71.9, 3 studies, 110 participants) as compared to that with GBT (17.2%, 95% CI 8.6-31.6, 4 studies, 153 participants). Substantial heterogeneity was found in studies using the lactulose breath test but not in studies using GBT. There was no significant difference in SIBO prevalence in patients with FD according to FD subtype. This meta-analysis suggests a link between FD and SIBO. The quality of evidence is low and can be largely attributed to the type of breath test for SIBO diagnosis and clinical heterogeneity. More appropriately designed studies are required to confirm the link between SIBO and FD.

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.

How the North American Consensus Protocol Affects the Performance of Glucose Breath Testing for Bacterial Overgrowth Versus a Traditional Method

The North American Consensus guidelines for glucose breath testing (GBT) for small intestinal bacterial overgrowth (SIBO) incorporated changes in glucose dosing and diagnostic cutoffs. We compared GBT positivity based on hydrogen and methane excretion and quantified symptoms during performance of the North American vs older modified Rome Consensus protocols. GBT was performed using the North American protocol (75 g glucose, cutoffs >20 parts per million [ppm] hydrogen increase after glucose and >10 ppm methane anytime) in 3,102 patients vs modified Rome protocol (50 g glucose, >12 ppm hydrogen and methane increases after glucose) in 3,193 patients with suspected SIBO. Positive GBT were more common with the North American vs modified Rome protocol (39.5% vs 29.7%, P < 0.001). Overall percentages with GBT positivity using methane criteria were greater and hydrogen criteria lower with the North American protocol (P < 0.001). Peak methane levels were higher for the North American protocol (P < 0.001). Times to peak hydrogen and methane production were not different between protocols. With the North American protocol, gastrointestinal and extraintestinal symptoms were more prevalent after glucose with both positive and negative GBT (P < 0.04) and greater numbers of symptoms (P < 0.001) were reported. GBT performed using the North American Consensus protocol was more often positive for SIBO vs the modified Rome protocol because of more prevalent positive methane excretion. Symptoms during testing were greater with the North American protocol. Implications of these observations on determining breath test positivity and antibiotic decisions for SIBO await future prospective testing.

Serum Gastrin Predicts Hydrogen-Producing Small Intestinal Bacterial Overgrowth in Patients With Abdominal Surgery: A Prospective Study.

OBJECTIVES:Small intestinal bacterial overgrowth (SIBO) might be associated with a history of abdominal surgery. We aimed to evaluate the prevalence of SIBO and to investigate serum gastrin and pepsinogen as predictors of SIBO in patients with a history of hysterectomy, gastrectomy, or cholecystectomy.METHODS:This prospective study surveyed 146 patients with a history of hysterectomy, gastrectomy, or cholecystectomy, and 30 healthy controls, who underwent a hydrogen (H2)-methane (CH4) glucose breath test (GBT) for SIBO. Serum pepsinogen I and II and gastrin levels were reviewed.RESULTS:GBT positivity (+) was significantly higher in patients with histories of abdominal surgery than that in in controls (37.6% vs 13.3%, P < 0.01). Among GBT+ patients, 36.0% (18/50), 96.2% (25/26), and 17.1% (12/70) were in the hysterectomy, gastrectomy, and cholecystectomy groups, respectively. Among the GBT subtypes, 43.6% (24/55), 10.9% (6/55), and 45.5% (25/55) of patients were in the GBT(H2)+, GBT(CH4)+, and GBT(mixed)+ groups, respectively. The gastrectomy group had significantly more GBT+ or GBT(H2)+ patients than the other surgical groups. Gastrin levels were higher in GBT(H2)+ patients and lower in GBT(CH4)+ patients than those in GBT− patients. Previous gastrectomy and elevated gastrin levels were independent predictive factors of GBT(H2)+.DISCUSSION:SIBO is not uncommon in patients with histories of abdominal surgeries, but it is more common in patients who have undergone gastrectomy. Serum gastrin level could be a serologic predictor of H2-producing SIBO. The relationship between serum gastrin and SIBO requires further research.

Small-bowel aspiration during upper esophagogastroduodenoscopy: Rao technique.

Small-bowel aspiration during upper esophagogastroduodenoscopy: Rao technique.

Small Intestinal Bacterial Overgrowth: Clinical Presentation in Patients with Roux-en-Y Gastric Bypass.

Small intestinal bacterial overgrowth (SIBO) is defined by an increased number of bacteria measured via exhaled hydrogen and/or methane gas following the ingestion of glucose. This condition is prevalent following abdominal surgery, including Roux-en-Y gastric bypass (RYGB), and associated with a variety of non-specific abdominal symptoms, often requiring an extensive diagnostic work-up. To assess the frequency that individuals with RYGB anatomy are diagnosed with SIBO and if they are more likely to report specific gastrointestinal (GI) symptoms compared to individuals with native anatomy. This large matched cohort study evaluated patients with GI symptoms who underwent a glucose breath test (GBT) for SIBO evaluation, utilizing 1:2 matching between RYGB and native anatomy. Patients with positive GBT were included in univariate and multivariate analyses to distinguish the presence of ten specific GI symptoms between RYGB and native anatomy. A total of 17,973 patients were included, where 271 patients with RYGB were matched to 573 patients with native anatomy that underwent GBT. Patients with RYGB anatomy and a positive GBT (199; 73.4%) as compared to those with native anatomy and a positive GBT (209; 36%) more often reported nausea, vomiting, bloating, and diarrhea. There were no differences between the two groups in the report of heartburn, regurgitation, chest pain, gas, or constipation. SIBO is common in patients with RYGB and more commonly report nausea, vomiting, bloating, and diarrhea. The results of this study suggest that the report of these symptoms in RYGB should prompt early evaluation for SIBO.

S0500 Intestinal Methanogen Overgrowth (IMO) in Parkinson's Disease: High Prevalence and Correlation With Constipation

INTRODUCTION: Recent ACG guidelines have defined intestinal methanogenic overgrowth (IMO) and described its clinical significance. The prevalences of small intestinal bacterial overgrowth (SIBO) and IMO in Parkinson's disease (PD) are unclear. SIBO in PD is linked to worse motor symptoms. Treatment of SIBO can improve motor function in PD. Our aim is to quantify the prevalence of SIBO and IMO in Parkinson's disease (PD) subjects with constipation compared to patients with unexplained GI symptoms undergoing glucose breath testing (GBT). METHODS: After an overnight fast and day of low-CHO diet, subjects brushed their teeth and rinsed their mouth with antiseptic mouthwash 2h before test. During GBT, 75 g of glucose dissolved in 250 mL water was administered. Breath samples were obtained at baseline and 15 min intervals for 2 h. Samples are collected in a bag (QuinTron Instrument Company, Inc.) and alveolar gas was analyzed for both H2 and CH4 levels by chromatography (QuinTron Micro Analyzer, QuinTron, Inc.). SIBO was defined as H2 rise of ≥20 ppm from baseline and/or CH4 rise of ≥10 ppm. IMO was defined as any measured CH4 ≥ 10 ppm. Daily bowel movements were assessed by prospective stool diary. Constipation was defined by <3 complete spontaneous bowel movements (CSBMs)/week. RESULTS: Nineteen patients with PD (68.2 ± 7.0 years, F/M = 6/13) underwent breath testing and compared to 158 subjects with unexplained GI symptoms (47.4 ± 15.3 years, F/M = 119/39). 31.6% (6/19) of PD subjects had SIBO versus 23.4% (37/158) of subjects with unexplained GI symptoms (P = 0.95), shown in Table 1. 52.6% (10/19) of PD subjects had IMO compared to 14.6% (23/158) subjects with unexplained GI symptoms (P < 0.001). 36.8% (7/19) had < 3 CSBMs per week. There was significant correlation between constipation and IMO, but not SIBO, Table 2. Higher maximum methane levels during GBT also significantly correlated with the presence of constipation. CONCLUSION: Rates of SIBO are similar between PD subjects with constipation and symptomatic patients undergoing GBT. More than half and significantly more PD subjects with constipation than symptomatic patients undergoing GBT have IMO. IMO and higher methane levels correlate with constipation in PD quantified by a stool diary. Methanogens may play a critical role in non-motor symptoms of PD patients such as constipation. ACKNOWLEDGEMENT: Parkinson's Foundation Translational Research Award.Table 1.: SIBO and IMO prevalence in subjects with PD vs unexplained GI symptomsTable 2.: Correlation between IMO, maximum methane level, and SIBO with constipation