Fructose Breath Test Research Articles

Detection capacity of small intestine bacterial or methanogen overgrowth by lactose and fructose breath testing in the adult population.

Exhaled breath tests (BTs) are the main diagnostic method for fructose and lactose malabsorption/intolerance (FI and LI, respectively) and for detecting small intestine bacterial or methanogen overgrowth (SIBO/IMO). Although FI/LI-BTs may provide evidence of the presence of SIBO/IMO, there is limited literature evaluating their reliability for this purpose. The objective of this study was to assess the sensitivity and specificity of FI/LI-BTs in detecting SIBO and their concordance with SIBO-BTs in the identification of IMO. In this retrospective observational study, FI/LI-BTs and SIBO-BTs performed in the same patients within a period of 6weeks were selected from 652 gas chromatography-based BTs. A total of 146 BTs from 67 eligible adult patients were identified. LI-BTs had higher specificity than FI-BT in detecting SIBO (93.8 % vs. 72.7 %). In contrast, FI-BTs showed higher sensitivity (60.0 % vs. 28.6 %) as FI was more frequently established in SIBO-positive patients (70 % vs. 29 %). With regard to IMO, concordance with LI-BT was 100 %, with a 27 % of false negatives on FI-BTs. Findings suggestive of SIBO or IMO on LI-BTs were highly consistent with those of SIBO-BTs. In contrast, the rate of false positives for SIBO and the rate of false negative for IMO on FI-BTs was 27 % in both cases.

Assessment of dietary interventions including low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet as management for fructose intolerance.

Abdominal pain remains one of the most common referral reasons to pediatric gastroenterology. Dietary intolerances are often considered but due to various factors are hardly pursued. We observed that diet review in large number of children with abdominal pain was high in sugary foods which led to food intolerance investigation and dietary intervention. A retrospective review was conducted of patients presenting with abdominal pain, diarrhea, or vomiting and negative GI evaluation, who underwent fructose breath testing. Patients younger than 20 years old who were seen between June 1, 2018 and March 1, 2021 were included. Statistical analysis was performed in R. There were 110 pediatric patients during the study period who underwent fructose breath testing, with 31% male and 69% female. The average age was 12.14 ± 4.01 years, and the average BMI was 21.21 ± 6.12. Abdominal pain was the most common presenting symptom (74.5%) followed by diarrhea and vomiting. Seventy-seven patients (70%) had a positive fructose breath test and were diagnosed with dietary intolerance to fructose. The 56 (67.5%) of those patients experienced symptoms during the breath test. Forty-three patients improved with dietary intervention. Twenty-seven on low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet and 16 on other diets. Based on analysis of our cohort of children with abdominal pain and high incidence of fructose intolerance as well as improvement in symptoms, following dietary changes, this condition should be considered and treated. Further investigation is needed to improve diagnostic testing but also into understanding mechanisms behind symptom presentation in this population.

Gene variants of the SLC2A5 gene encoding GLUT5, the major fructose transporter, do not contribute to clinical presentation of acquired fructose malabsorption

BackgroundWhile role of ALDOB-related gene variants for hereditary fructose intolerance is well established, contribution of gene variants for acquired fructose malabsorption (e.g. SLC2A5, GLUT5) is not well understood.MethodsPatients referred to fructose breath test were further selected to identify those having acquired fructose malabsorption. Molecular analysis of genomic DNA included (I) exclusion of 3 main ALDOB gene variants causing hereditary fructose intolerance and (II) sequencing analysis of SLC2A5 gene comprising complete coding region, at least 20 bp of adjacent intronic regions and 700 bp of proximal promoter.ResultsAmong 494 patients, 35 individuals with acquired fructose malabsorption were identified based on pathological fructose-breath test and normal lactose-breath test. Thirty four of them (97%) had negative tissue anti-transglutaminase and/or deamidated gliadin antibodies in their medical records. Molecular analysis of SLC2A5 gene of all 35 subjects identified 5 frequent and 5 singular gene variants mostly in noncoding regions (promoter and intron). Allele frequencies of gene variants were similar to those reported in public databases strongly implying that none of them was associated with acquired fructose malabsorption.ConclusionsGene variants of coding exons, adjacent intronic regions and proximal promoter region of SLC2A5 gene are unlikely to contribute to genetic predisposition of acquired fructose malabsorption.

Expression of the fructose transporter GLUT5 in patients withfructose malabsorption.

Patients with abdominal symptoms are frequently diagnosed with fructose malabsorption (FM). Fructose is absorbed by monosaccharide transporters located in the brush border of the human small intestine. The aim of this study was to investigate the histoanatomical distribution of the main fructose transporter GLUT5. We studied 223 patients diagnosed with FM by a hydrogen breath test and grouped according to their response to a fructose-free diet. The control group were 42 healthy individuals and 29 patients with celiac disease (CD). The fructose breath test was done with 50 g fructose. The expression of Glut5 in duodenal biopsy specimens was studied by immunohistochemistry. The Kruskal-Wallis-test and Mann-Whitney U-test were used to carry out the statistical analysis. The histoanatomical expression pattern of GLUT5 did not differ significantly between those patients with FM who responded completely to a fructose-free diet (n = 183) and healthy individuals (n = 42); nor did it correlate to H2 production measured in fructose breath testing. In patients with FM, the GLUT5 expression pattern did not differ between those individuals responding to a fructose-free diet and those who did not. However, GLUT5 expression pattern was significantly different in patients with CD (n = 29) compared to patients with FM and to healthy individuals (p = 0.009). GLUT5 expression patterns are not be related to adult patients with FM. However, in secondary malabsorption, a decreased GLUT5 expression was found. Further investigation is needed to understand the essential factors in FM and the influence on functional gastrointestinal disorders.

Fructose Malabsorption in Chilean Children Undergoing Fructose Breath Test at a Tertiary Hospital

Fructose is a highly abundant carbohydrate in western diet and may induce bowel symptoms in children as in adults. The main objective of this study is to describe the frequency of fructose malabsorption (FM) in symptomatic patients 18 years or younger undergoing fructose breath test in a single tertiary center between 2013 and 2018, and to evaluate whether certain symptoms are related to positivity of the test. Out of 273 tests 183 (67%) were compatible with FM. The most frequent pretest symptom in the overall study population was bloating (83%), followed by abdominal pain (73%). Patients with positive test were younger than those with a negative test (median 5 vs 8 years, P < 0.001). In multivariate analysis, which included age, sex, and symptoms (diarrhea, abdominal pain, bloating, nausea), only age <6 years (odds ratio 2.93, 95% confidence interval 1.64-5.23) and absence of nausea (odds ratio = 3.32, 95% confidence interval 1.56-7.05) were associated with FM.

Evaluation of lactulose, lactose, and fructose breath testing in clinical practice: A focus on methane.

Background and AimBreath testing (BT) is used to identify carbohydrate malabsorption and small intestine bacterial overgrowth. Measuring methane alongside hydrogen is advocated to reduce false‐negative studies, but the variability of methane production is unknown. The aim of this study is to examine the effect of high methane production on hydrogen excretion after ingesting lactulose, fructose, or lactose.MethodsA retrospective audit was performed of patients with gastrointestinal symptoms who underwent BT. Following a low fermentable carbohydrate diet for 24‐h, a fasting BT before consuming 35 ml lactulose, 35 g fructose, or lactose in 200 ml water, followed by BT every 10–15 min for up to 3‐h, was performed. A positive test was defined as a ≥20 ppm rise of hydrogen or methane from baseline. A high methane producer had an initial reading of ≥5 ppm. Breath hydrogen and methane production were measured as area under the curve. Chi‐squared tests were used to compare proportions of those meeting the cut‐off criteria.ResultsOf patients, 26% (28/106) were high methane producers at their initial lactulose test. The test–retest repeatability of methane production was high, with the same methane production status before ingesting lactose in all (70/70) and before ingesting fructose in most (71/73). Methane production was highly variable during testing, with 38% (10/26) having ≥1 reading lower than baseline. Hydrogen produced by high or low methane producers did not differ (1528 [960–3645] ppm min vs 2375 [1810–3195] ppm min [P = 0.11]). Symptoms and breath test results were not positively related.ConclusionThe validity of including an increase of ≥20 ppm methane to identify carbohydrate malabsorption or small intestine bacterial overgrowth should be questioned due to the variability of readings during testing.

Is abnormal 25 g fructose breath test a predictor of symptomatic response to a low fructose diet in irritable bowel syndrome?

Fructose malabsorption may trigger gastrointestinal symptoms in irritable bowel syndrome patients and a low fructose diet seems to improve digestive symptoms. The aim of our study was to determine whether fructose malabsorption detected by a 25g fructose breath test could be a predictor of the efficacy of a low fructose diet. 88 patients (73 women, median age, 45.5 years, range 18-69) with irritable bowel syndrome according to Rome III criteria were included in this prospective, controlled study. All 88 patients had a 25g fructose breath test; 37 had a positive test result defining fructose malabsorption. All 88 patients followed a low fructose diet for 2 weeks, blinded to their test results. Patients filled self validated-questionnaires before and at the end of the dietary period. The main outcome measurement was the Irritable Bowel Syndrome-Symptom Severity Score. Irritable Bowel Syndrome-Symptom Severity Score significantly decreased in fructose absorbers and fructose malabsorbers after a low fructose diet (-68.0 [-137; 0] versus-73.5 [-173;-11.5]) with no difference according to fructose breath test result (adjusted P=0.984). A positive 25g fructose breath test is not a predictor of the efficacy of a low fructose diet in irritable bowel syndrome. REGISTERED CLINICAL TRIAL: www.clinicaltrials.gov (NCT02188680).

A Pilot Study of the Effect of Green Kiwifruit on Human Intestinal Fermentation Measured by Hydrogen and Methane Breath Testing.

We investigated the impact of the ingestion of two green kiwifruit (Actinidia deliciosa var. Hayward) and one Royal Gala apple on breath hydrogen and methane production in humans. Consumption of two green kiwifruit led to no evidence of carbohydrate malabsorption (0/20), whereas consumption of one apple was associated with carbohydrate malabsorption in 6/20 participants (P = .008). There were no significant differences in the area under the curve for hydrogen or methane breath concentrations after consumption of the two fruits. Rates of lactose and fructose breath tests in this cohort were within expected parameters. Green kiwifruit are not associated with clinically significant carbohydrate malabsorption compared with apples in this pilot study.

Repeatability and effect of blinding of fructose breath tests in patients with functional gastrointestinal disorders.

Breath tests are used as measures of sugar intolerance or malabsorption in patients with functional gastrointestinal disorders (FGID), although the repeatability or anticipatory bias have not been adequately studied. We examined the repeatability and anticipatory bias during fructose breath testing using a nocebo-controlled, randomized, cross-over, and double-blind study design. Gastrointestinal symptoms and breath concentrations of hydrogen and methane were documented during breath tests with fructose (given open twice and blinded once), water (blind neutral nocebo) and a cyclamate/saccharine sweetener (blind sweet nocebo) on 5days in patients with FGID. Repeatability of fructose breath tests (16 patients) and differences between open and blinded substrate groups (31 patients) was assessed using thresholds for intolerance and malabsorption, and areas-under-the-curve (AUC) of symptoms and breath gas concentrations. Fructose breath tests showed moderate repeatability for intolerance status (absolute agreement 87%, kappa 0.72), but limited repeatability for malabsorber status (absolute agreement 53%, kappa 0.05). Repeatability of AUCs of GI symptoms, hydrogen and methane breath concentrations was moderate (intraclass correlation coefficients 0.70, 0.57, and 0.57, respectively). There were no significant differences between open and blinded fructose breath tests in intolerance or malabsorber status, or in AUCs of GI symptoms, hydrogen and methane concentrations. Fructose breath tests showed moderate repeatability for intolerance status and for AUCs of symptoms and gas concentrations, lying within the range of accepted gastrointestinal sensory and transit tests. Repeatability for malabsorption status was inadequate and requires revisiting. The fructose breath test can be used unblinded in FGID.

The Predictive Value of the Hydrogen Breath Test in the Diagnosis of Fructose Malabsorption

Background: Fructose malabsorption is commonly diagnosed by the hydrogen fructose (H₂) breath test. However, the mechanisms behind fructose malabsorption in humans are not well understood and the clinical relevance of this test is considered controversial. Hence, the main aim of this study is to evaluate the predictive value of the H₂ breath test. Methods: Regarding exclusion criteria, the study enrolled 562 consecutive patients, enlisted to a gastroenterology clinic between 2009 and 2011 for testing malabsorption. In the final data analysis, 246 patients were included. Ecotrophologists used 3 categories to rate dietary success: complete response, partial response and no response to the diet. They also rated the occurrence of abdominal pain, diarrhoea and bloating during the H₂ breath test. Ordinal regression analysis using SPSS was performed to evaluate whether H₂ breath test results – measured as the maximum H₂ level, the maximum increase in H₂, and the area under the curve (AUC) – predicted dietary success or failure. Correlation analyses were applied to test whether symptoms of fructose malabsorption correlated with the H₂ breath test measures. Finally, we evaluated whether cut-off-values of 40 or 60 parts per million (ppm) serve better than the test measure of 20 ppm to diagnose fructose malabsorption. Results: When a fructose-free diet was administered it was found that 103 patients (41.9%) were complete responders, 116 (47.2%) were partial responders and 27 (11%) were non-responders. The H₂ breath test with the 20 ppm cut-off-value, that is, the maximum H₂ level, the maximum increase in H₂, and the AUC did not predict dietary response (all 95% CI ns). This was also the case when using 40 or 60 ppm as cut-off-values (all 95% CI ns). Abdominal pain during the test correlated significantly with the AUC. Diarrhoea and bloating correlated significantly with the AUC, the maximum H₂ level and the maximum increase in H₂ (p < 0.05). Conclusions: The H₂ breath test produced no predictive value for the fructose-free diet outcomes; its value as a predictive test is therefore questionable. However, the symptoms of fructose malabsorption correlated significantly with the H₂ breath test measures, and this is an indication that there is at least a degree of validity of the H2 breath test beyond the simple detection or exclusion of fructose malabsorption.

Relationship Between Abdominal Symptoms and Fructose Ingestion in Children with Chronic Abdominal Pain

BackgroundLimited valid data are available regarding the association of fructose-induced symptoms, fructose malabsorption, and clinical symptoms.AimTo develop a questionnaire for valid symptom assessment before and during a carbohydrate breath test and to correlate symptoms with fructose breath test results in children/adolescents with functional abdominal pain.MethodsA Likert-type questionnaire assessing symptoms considered relevant for hydrogen breath test in children was developed and underwent initial validation. Fructose malabsorption was determined by increased breath hydrogen in 82 pediatric patients with functional abdominal pain disorders; fructose-induced symptoms were quantified by symptom score ≥2 and relevant symptom increase over baseline. The results were correlated with clinical symptoms. The time course of symptoms during the breath test was assessed.ResultsThe questionnaire exhibited good psychometric properties in a standardized assessment of the severity of carbohydrate-related symptoms. A total of 40 % (n = 33) had malabsorption; symptoms were induced in 38 % (n = 31), but only 46 % (n = 15) with malabsorption were symptomatic. There was no significant correlation between fructose malabsorption and fructose-induced symptoms. Clinical symptoms correlated with symptoms evoked during the breath test (p < 0.001, r2 = 0.21) but not with malabsorption (NS). Malabsorbers did not differ from non-malabsorbers in terms of symptoms during breath test. Symptomatic patients had significantly higher pain and flatulence scores over the 9-h observation period (p < 0.01) than did nonsymptomatic patients; the meteorism score was higher after 90 min.ConclusionsFructose-induced symptoms but not fructose malabsorption are related to increased abdominal symptoms and have distinct timing patterns.

Poor reproducibility of breath hydrogen testing: Implications for its application in functional bowel disorders.

Limited data are available regarding the reproducibility of lactulose and fructose breath testing for clinical application in functional bowel disorders. The purpose of this study was to investigate the reproducibility of lactulose and fructose breath hydrogen testing and assess symptom response to fructose testing. Results were analysed from 21 patients with functional bowel disorder with lactulose breath tests and 30 with fructose breath tests who completed another test >2 weeks later. Oro-caecal transit time, hydrogen responses, both qualitatively (positive/negative) and quantitatively (area under the curve (AUC) for hydrogen), were compared between tests. In another 36 patients, data scores for overall abdominal symptoms, abdominal pain, bloating, wind, nausea and fatigue were collected during the fructose test and compared to hydrogen responses. No correlations were found for lactulose AUC (linear regression, p = 0.58) or transit time (Spearman's p = 0.54) between tests. A significant proportion (30%) lost the presence of fructose malabsorption (p < 0.01). Hydrogen AUC for fructose did not correlate between tests, (r = 0.28, p = 0.17) independent of time between testing (p = 0.82). Whilst patients with fructose malabsorption were more likely to report symptoms than those without (56% vs 17%; p = 0.04), changes in symptom severity were not different (p > 0.05). Routine use of lactulose and fructose breath tests in functional bowel disorder patients is not supported due to its poor reproducibility and low predictive value for symptom responses.

Does calprotectin level identify a subgroup among patients suffering from irritable bowel syndrome? Results of a prospective study.

Irritable bowel syndrome is a multifactorial disease. Although faecal calprotectin has been shown to be a reliable marker of intestinal inflammation, its role in irritable bowel syndrome remains debated. The aims of this prospective study were to select a subgroup of irritable bowel syndrome patients and to characterise those patients with high faecal calprotectin by systematic work-up. Calprotectin levels were determined by enzyme-linked immunosorbent assay test in consecutive irritable bowel syndrome patients fulfilling Rome III criteria in whom normal colonoscopy and appropriate tests had excluded organic disease. Calprotectin levels were compared in irritable bowel syndrome patients, healthy controls and patients with active and quiescent Crohn's disease. When the calprotectin level was higher than 50 µg/g, the absence of ANCA/ASCA antibodies and a normal small bowel examination were required to confirm irritable bowel syndrome diagnosis. Additional explorations included assessment of irritable bowel syndrome severity, anxiety and depression, impact on quality of life, glucose and fructose breath tests, rectal distension test by barostat and quantitative and qualitative assessment of inflammation on colonic biopsies. Among the 93 irritable bowel syndrome patients (73% women; 66.7% with diarrhoea) recruited, 34 (36.6%) had reproducibly elevated calprotectin. Although they tended to be older than those with normal calprotectin (P = 0.06), there were no other differences between the two groups. When elevated, calprotectin was correlated with age (P = 0.03, r = 0.22). Elevated faecal calprotectin was observed in one third of patients in this series, without any significant association with a specific clinical phenotype (except age) or specific abnormalities.

Endoscopically Assisted Glucose Breath Test: A Novel Diagnostic Approach for Distal SIBO

Introduction: Small intestinal bacterial overgrowth (SIBO) is characterized by excessive amount of bacteria in the small intestine along with abdominal pain, bloating, gas, and diarrhea. Although oral glucose breath test (GBT) and duodenal aspirate/culture are used to assess proximal SIBO, at present, there is no practical method to identify distal SIBO. We aimed to determine whether direct administration of glucose into the distal duodenum/jejunum can identify SIBO. Methods: Patients with unexplained GI symptoms >1 yr, negative endoscopy, colonoscopy and CT underwent standard GBT, and within a week had upper endoscopy, during which distal duodenal juice was aspirated for aerobic/anaerobic culture and 75g glucose dissolved in 250cc water was directly administered into the 4th part of duodenum. Breath samples were collected for hydrogen/methane at baseline and every 15min for 2h. Symptom profiles and results of GBT, endoscopically assisted glucose breath test (EAGBT) and duodenal cultures were analyzed and compared. Results: 9 patients (m/f=6/3), mean age 45y, participated. Bloating, abdominal pain, cramping, nausea, and belching were the main symptoms present in 89% of patients. 7/9 subjects had a GBT and 1/9 had a fructose breath test (diabetic). Overall, 1/8 (12.5%) patients had a positive test suggesting proximal SIBO and 7/8 (87.5%) had a negative test. In contrast, 8/9 (89%) had a positive EAGBT suggesting distal SIBO (Table 1). 7/9 (78%) patients were symptomatic during the EAGBT. 7/9 (78%) patients had positive cultures (>103 CFU/mL); 4 grew S. viridans, 1 grew Veillonella, 2 grew MSSA, 3 grew alpha-hemolytic streptococcus, 1 grew H. parainfluenzae and 1 grew E.Coli. Eight were >103 CFU/mL, 4 were >104 CFU/mL, and 1 was >105 CFU/mL. EAGBT (85%) was more sensitive than GBT (16%) (Table 1). Although baseline hydrogen levels were similar, baseline methane, peak hydrogen and methane levels and AUC were higher in EAGBT vs. GBT (Table 2). Average AUC was higher using EAGBT with nearly 10 fold higher hydrogen levels (p= 0.06) and nearly twice as high methane level measured (Table 2).Table 1: Positive and Negative Diagnostic Agreement between Breath Test and Culture DataTable 2: Baseline and Peak Hydrogen and Methane Levels as well as AUC in Both Glucose Breath TestsConclusion: EAGBT is a novel method of identifying distal SIBO. It appears to be a safe and practical technique for detecting distal SIBO, and, in our cohort, had a similar yield as duodenal aspirate/culture. EAGBT could be an appropriate next step for patients with high index of suspicion for SIBO or in whom an oral glucose breath test is negative.Figure 1

Usage of Rifaximin for the Treatment of Hydrogen Positive Small Intestinal Bacterial Overgrowth

Introduction: Small intestinal bacterial overgrowth (SIBO) is challenging to treat and diagnose and is associated with diagnosis of Irritable Bowel Syndrome (IBS). Although no FDA approved medications exist for treatment of SIBO, rifaximin has recently been FDA approved for the treatment of diarrheapredominant IBS, and has been recommended for treatment of patients with specifically methane positive SIBO breath tests. The aim of this study was to evaluate patient symptom response to rifaximin for SIBO based on breath test results. Methods: All patients undergoing breath testing to evaluate for SIBO at our tertiary-care motility center from 9/2012 to 3/2016 were included. Patients were defined as having a positive glucose or fructose (if diabetic) breath test for SIBO if there was an increase of ≥ 20 ppm of hydrogen and/or ≥ 10ppm of methane by 90 minutes (Rezaie et al; DDW 2016 Presentation#450).Patient demographic and symptom data, antibiotic treatment regimens, symptomatic response to therapy, and repeat treatments were recorded. IRB approval was obtained. Results: A total of 53 of 443 patients had positive breath testing for SIBO during the study period. Of these, 79.2% (42/53) were women, mean age 58 years (Range 16-86 years; SD 16.7). The most common symptoms for performing breath testing were abdominal bloating (60.4%), diarrhea (47.2%), excessive flatulence (30.2%), abdominal pain (24.5%), nausea (22.6%), and constipation (20.8%). At the time of the retrospective review, 42/53 (79.2%) had received antibiotic therapy. Therapeutic results were available in 28/42 (66.7%) (19 predominantly hydrogen positive; 4 methane positive; 5 both). Rifaximin was the most commonly prescribed antibiotic (78.4%). Response rates to rifaximin were 47.4% for hydrogen positivity alone (38.5% 1st line; 66.7% 2nd line); and 80% for both hydrogen and methane positivity (75% 1st line; 100% 2nd line). No patients with methane positivity alone were effectively treated with rifaximin. Conclusion: Rifaximin was the most commonly prescribed antibiotic regimen for SIBO therapy. Patients with hydrogen or hydrogen and methane positive breath tests responded better to rifaximin than those with methane positivity alone. Hydrogen positive SIBO rifaximin response rates were similar to prior TARGET 3 Study data of 36% rifaximin response in diarrhea predominant IBS, suggesting overlap of these conditions. Future prospective studies using rifaximin in a larger cohort may be warranted to validate our findings.

PWE-062 Fructose Intolerance in Pelvic Radiation Disease; Is It More Common than We Realised?

Introduction Guidelines have recently been published regarding the management of Pelvic Radiation Disease (PRD) and late effects of cancer care. 1 The guidelines have been shown in peer reviewed studies to be effective in the management of PRD. 2 The guidelines include a number of investigations for certain symptoms and include carbohydrate tolerance tests for substrates such as fructose. That said there are currently no published case series or studies evaluating the prevalence and diagnostic yield of fructose breath testing in PRD. We have recently set up a dedicated late effects of cancer care and pelvic radiation disease clinic in Cardiff and audited the results of our fructose tolerance breath tests. Patients with diarrhoea, bloating or abdominal pain were investigated with fructose breath testing as per these guidelines. Methods We audited the results for all fructose breath tests in 2014 in patients with suspected PRD via a database search and correlation with clinical notes. Total of 82 patients were identified as having a fructose breath tests in the 1 year period) 20 of which were being investigated for suspected PRD. (10 Male, 10 female, median age 65.5) Results 45% of fructose breath tests in patients with suspected PRD were positive (n = 9) All of these patients were referred with either diarrhoea, bloating or abdominal pain. Of these patients with positive tests, 44% were found to have a dual pathology (n = 4) with other diagnoses including small intestinal bacterial overgrowth, lactose intolerance and bile acid diarrhoea. Conclusion Fructose intolerance is common in patients with diarrhoea, bloating and abdominal pain in PRD. The diagnostic yield of testing is high and should be considered as a differential diagnosis in these patients. It is important to recognise that dual pathology frequently occurs and that an algorithmic approach is useful in these patients. References 1 Andreyev HJN, Muls AC, Norton C, Ralph C, Watson L, Shaw C, et al . Guidance: The practical management of the gastrointestinal symptoms of pelvic radiation disease. Frontline Gastroenterology [Internet]. BMJ Publishing Group Ltd; 2014 Jun 17;flgastro–2014–100468. Available from: http://fg.bmj.com/content/early/2014/06/17/flgastro-2014-100468.abstract 2 Andreyev HJN, Benton BE, Lalji A, Norton PC, Kabir M, GaugeGage PH, et al . ArticlesAlgorithm-based management of patients with gastrointestinal symptoms in patients after pelvic radiation treatment (ORBIT): a randomised controlled trial. Lancet. Elsevier Ltd; 2013 Sep 20;1–9. Disclosure of Interest None Declared

Mo1308 Factors Affecting Response to Low FODMAPs Therapy in the Management of Irritable Bowel Syndrome; Fructose and Lactose Breath Testing, IBS Subtype and Symptom Severity

Introduction A low FODMAPs diet is an effective dietary intervention for the management of irritable bowel syndrome (IBS). We hypothesised that hydrogen breath testing (HBT) for lactose and fructose intolerance would identify potential responders. Secondly we hypothesised that greater improvement would be seen in diarrhoea predominant (IBS-D) than other subtypes. Methods 167 consecutive patients with a Rome III IBS diagnosis who completed low FODMAPs dietary education therapy were analysed. Symptoms were assessed at baseline and follow up (median 63 days post-treatment) via self-administered questionnaire. The primary endpoint was a symptom severity score (scale 0–5) based on pain, bloating, constipation and diarrhoea. According to clinician choice, some patients underwent HBT with fructose 30 gm (n = 74) and lactose 30 gm (n = 103). Results Subtypes were IBS-D (n = 91, 67 f, mean age 42), IBS-C (n = 41, 35 f, mean age 45) and IBS-M (n = 34, 29 f, mean age 36). Across all patients, an improvement in symptom severity (2.4 to 1.6, p Conclusion A low FODMAP diet may particularly beneficial in patients with fructose malabsorption. Severity of symptoms at baseline may predict degree of improvement which may explain the greater response seen in IBS-M patients in this study. A low FODMAP diet may particularly beneficial in patients with fructose malabsorption. Severity of symptoms at baseline may predict degree of improvement which may explain the greater response seen in IBS-M patients in this study. Disclosure of Interest None Declared

Mechanisms Of Fructose Absorption

Mechanisms Of Fructose Absorption

A Suggested Strategy for Approaching Unexplained Abdominal Bloating Using Glucose and Fructose Breath Testing

Introduction: Unexplained bloating is one of the most common and bothersome gastroenterology complaints. Bloating is likely to present in association with belching, flatulence, post-prandial distension, borborygmi, pain, and diarrhea. Patients with such symptoms are usually placed on a lactose and/or gluten free diet and if they do not improve they undergo blood and stool tests, imaging studies and endoscopic procedures to rule out organic etiologies. If this fails to diagnose the problem, then these patients are placed into the category of functional GI disorder. Small bowel bacterial overgrowth (SIBO) and dietary fructose intolerance (DFI) are responsible for bloating and other nonspecific GI symptoms. Their exact prevalence is unknown because they are poorly recognized an as a consequence poorly managed. This study attempts to investigate the usefulness of breath testing to identify SIBO and DFI in unexplained bloating patients. Methods: Since December 2012, we studied 257 patients referred to our motility center with unexplained abdominal bloating. They underwent glucose breath test (GBT) to assess for SIBO. GBT was performed after a 100 gm oral glucose load with breath sample collection at baseline and every 20 minutes for 3 hours to measure hydrogen and methane concentrations. A test was considered to be positive if the baseline or peak hydrogen concentrations during the study exceeded 20 parts per million (ppm), or methane level at baseline or latter peaked at > 10 ppm. Patients with a negative GBT were then recommended to undergo a fructose breath test (FBT) and 56 agreed to participate. FBT was performed after 25 gm fructose oral administration, Breath sampling and positive parameters were the same as described above. Results: 111 out of 257 patients (43%) were positive for SIBO by GBT. Subsequently, 26 out of 56 patients (46 %) (F: 48, mean age: 53) were found to have DFI with a positive FBT. The average time to a positive FBT was 91 min. Only one FBT was positive based on methane concentration, the rest had increased hydrogen concentrations. Conclusion: 1) GBT to exclude SIBO should be considered as the next step to evaluate unexplained abdominal bloating. 2) A negative GBT should then trigger a FBT to detect fructose intolerance since 46 % of negative GBT patients were found to be fructose intolerant. 3) Our data provides a diagnostic pathway to identify therapeutic targets for the challenging complaint of unexplained bloating.

Fructose Malabsorption in Systemic Sclerosis.

The deleterious effect of fructose, which is increasingly incorporated in many beverages, dairy products, and processed foods, has been described; fructose malabsorption has thus been reported in up to 2.4% of healthy subjects, leading to digestive clinical symptoms (eg, pain, distension, diarrhea). Because digestive involvement is frequent in patients with systemic sclerosis (SSc), we hypothesized that fructose malabsorption could be responsible for intestinal manifestations in these patients.The aims of this prospective study were to: determine the prevalence of fructose malabsorption, in SSc; predict which SSc patients are at risk of developing fructose malabsorption; and assess the outcome of digestive symptoms in SSc patients after initiation of standardized low-fructose diet.Eighty consecutive patients with SSc underwent fructose breath test. All SSc patients also completed a questionnaire on digestive symptoms, and a global symptom score (GSS) was calculated.The prevalence of fructose malabsorption was as high as 40% in SSc patients. We also observed a marked correlation between the presence of fructose malabsorption and: higher values of GSS score of digestive symptoms (P = 0.000004); and absence of delayed gastric emptying (P = 0.007). Furthermore, in SSc patients with fructose malabsorption, the median value of GSS score of digestive symptoms was lower after initiation of standardized low-fructose diet (4 before vs. 1 after; P = 0.0009).Our study underscores that fructose malabsorption often occurs in SSc patients. Our findings are thus relevant for clinical practice, highlighting that fructose breath test is a helpful, noninvasive method by: demonstrating fructose intolerance in patients with SSc; and identifying the group of SSc patients with fructose intolerance who may benefit from low-fructose diet. Interestingly, because the present series also shows that low-fructose diet resulted in a marked decrease of gastrointestinal clinical manifestations in SSc patients with fructose malabsorption, our findings underscore that fructose malabsorption may play a significant role in the onset of gastrointestinal symptoms in these patients. Finally, we suggest that fructose malabsorption may be due to reduced fructose absorption by enterocytes, impaired enteric microbiome, and decreased intestinal permeability.