Fructose Malabsorption Research Articles

Carbohydrate Malabsorption and Putative Carbohydrate-Specific Small Intestinal Bacterial Overgrowth: Prevalence and Diagnostic Overlap Observed in an Austrian Outpatient Center

Background/Aims: While lactose malabsorption is a well-investigated condition, few epidemiologic data are available for fructose and sorbitol malabsorption. The aim of this study was to assess the prevalence rates for primary lactose malabsorption, fructose and sorbitol malabsorption, and carbohydrate-specific small intestinal bacterial overgrowth (cs-SIBO) in an Austrian outpatient center. Methods: In total, 306 adult patients, who were primarily referred with suspected carbohydrate malabsorption by general practitioners to our outpatient clinic, underwent genetic testing (C/T_-13910 polymorphism) for primary lactose malabsorption, and a combined hydrogen (H₂)/methane (CH₄) breath test for fructose (25 g) and sorbitol (12.5 g) malabsorption. Cohen's kappa (κ) was calculated for agreement between positive breath test results and self-reported symptoms during the test. Results: Seventy-eight (25.49%) patients were C/C_-13910 homozygotes, indicating primary lactose malabsorption. Thirty-four (11.11%) and 57 (18.63%) patients were classified as fructose and sorbitol malabsorbers. Cohen's κ measuring agreements between positive fructose and sorbitol breath test results and self-reported symptoms during the test were 0.33 and 0.49, respectively. Twenty-nine (9.50%) patients with an early H₂/CH₄ peak (i.e. within 60 minutes after fructose and/or sorbitol ingestion) were diagnosed with cs-SIBO. Conclusion: In Austria, carbohydrate malabsorption is a frequent condition in patients referred by general practitioners to carbohydrate malabsorption testing.

Is fructose malabsorption a cause of irritable bowel syndrome?

Irritable Bowel Syndrome (IBS) is a condition that may be marked by abdominal pain, bloating, fullness, indigestion, belching, constipation and/or diarrhea. IBS symptoms can result from malabsorption of fructose. Fructose is a monosaccharide found naturally in small quantities in fruits and some vegetables, and in much larger quantities in industrially manufactured sweets with added sugars (e.g. sucrose and high fructose corn syrup). Fructose malabsorption leads to osmotic diarrhea as well as gas and bloating due to fermentation in the colon. A low-fructose diet has been found to improve IBS symptoms in some patients. This paper discusses the prevalence of fructose malabsorption and considers fructose ingestion as a possible cause of--and fructose restriction as a possible dietary treatment for--IBS.

Carbohydrate malabsorption and carbohydrate-specific small intestinal bacterial overgrowth: diagnostic approach and overlap

Background: Carbohydrate malabsorption is a considerable problem in patients with non-specific abdominal complaints. While lactose malabsorption is well investigated, few epidemiologic data are available for fructose and sorbitol malabsorption or combined carbohydrate malabsorption syndromes. The purpose of this study was to assess the prevalence rates for primary lactose malabsorption, fructose and sorbitol malabsorption, and carbohydrate-specific small intestinal bacterial overgrowth (cs-SIBO) in an Austrian outpatient center. Additionally the diagnostic value of methane (CH4) measurements in carbohydrate malabsorption breath testing was evaluated.

Optimal Testing for Diagnosis of Fructose Malabsorption: Under-dosage Leads to False Negative Intolerance Test.

TO THE EDITOR: With great interest we have been following the discussion about our study published in Journal of Neurogastroenterology and Motility.1 We highly estimate the recent constructive comments expressed by the authors Erdogan and colleagues2 and would like to make some conclusive remarks. We fully agree with the authors that all patients with irritable bowel syndrome (IBS)-like symptoms should undergo breath testing and have specifically stated this in our manuscript. Thus, we are not sure where Erdogan et al2 got the notion that such tests should only be performed for research purposes. We furthermore agree with Erdogan et al2 that 2 consecutive breath tests are impractical, especially considering the bothersome symptoms that patients experience during and after testing. Therefore, we favor the breath test with 50 g fructose. From our yet unpublished data we know that H2 breath tests with 50 g fructose identify patients with IBS-like symptoms who will benefit from a fructose-reduced diet. If only 25 g tests were performed, an important subgroup (the ones with symptomatic 50 g breath test) would be missed although they greatly benefit from a detailed dietary counseling, while patients with positive 25 g breath test already benefit from brief dietary advice as shown by a decline in gastrointestinal (GI) symptoms, improved quality of life and state of health. In patients with severe fructose malabsorption only the detailed dietary advice regimen resulted in improvement of GI symptoms and perceived state of health. This is our rationale to perform a breath test with 50 g of fructose. The German consensus paper on clinically relevant breath tests in gastroenterological diagnostics does not always recommend a test with 50 g. It points out that in case of highly suspected fructose malabsorption, the high dose test should be performed first and in case of a positive outcome, an additional 25 g test enhances specificity.3 On the other hand, the rationale to start with the low dose is that healthy volunteers almost never malabsorb 25 g. Thus, the test has an excellent specificity because, according to test criteria, there are rarely false positives. However, we feel that the low dose test lacks sensitivity because a proportion of negative low dose breath testers will still respond to a fructose elimination diet. To deal with the lower specificity in the high dose test, observing symptoms during the test can help: increased H2 excretion combined with typical symptoms triggered by the high dose challenge is a good criterion to distinguish between true and false positive patients, and healthy volunteers barely report symptoms even though they may have elevated H2 excretion.4 Some healthy subjects and patients with IBS-like symptoms are able to fully absorb 50 g of fructose because otherwise, every test person would have significant H2 excretion and symptoms. In our study 64% were symptomatic fructose malabsorbers with a 50 g test dose, which in reverse implies that 36% of patients with unclear abdominal discomfort were able to absorb 50 g of fructose without clinical symptoms. We disagree with the authors that amounts > 25 g of fructose are nowadays not consumed at once. As recently outlined, a 16-oz bottle of apple juice may contain > 30 g fructose and a 22-oz soft drink could contain approximately 30 g to 40 g depending on the percent fructose in the corn syrup sweetener,5,6 both representing liquids regularly consumed by a large proportion of the population. As clinicians we will accept false positives. They may undergo a 4–6 weeks dietary trial and not respond. But it is unpleasant to exclude patients, in whom most of the treatments have failed, from a fructose elimination diet that works most of the time in these patients because their diagnosis was missed. Thus, we find it more appropriate to use the high dose test with 50 g because we feel that it is clinically more relevant.

A Grounded Guide to Gluten: How Modern Genotypes and Processing Impact Wheat Sensitivity

The role of wheat, and particularly of gluten protein, in our diet has recently been scrutinized. This article provides a summary of the main pathologies related to wheat in the human body, including celiac disease, wheat allergy, nonceliac wheat sensitivity, fructose malabsorption, and irritable bowel syndrome. Differences in reactivity are discussed for ancient, heritage, and modern wheats. Due to large variability among species and genotypes, it might be feasible to select wheat varieties with lower amounts and fewer types of reactive prolamins and fructans. Einkorn is promising for producing fewer immunotoxic effects in a number of celiac research studies. Additionally, the impact of wheat processing methods on wheat sensitivity is reviewed. Research indicates that germination and fermentation technologies can effectively alter certain immunoreactive components. For individuals with wheat sensitivity, less-reactive wheat products can slow down disease development and improve quality of life. While research has not proven causation in the increase in wheat sensitivity over the last decades, modern wheat processing may have increased exposure to immunoreactive compounds. More research is necessary to understand the influence of modern wheat cultivars on epidemiological change.

The Role of Low FODMAP Diet in the Management of Irritable Bowel Syndrome

The Role of Low FODMAP Diet in the Management of Irritable Bowel Syndrome

Fiber, food intolerances, FODMAPs, gluten and functional gastrointestinal disorders--update 2014

The controversial effects of dietary fiber on symptoms in functional gastrointestinal disorders are summarized. Studies concerning adverse reaction to foods are mentioned and the possible role of food allergy and food intolerances, especially pseudoallergic reactions to biogenes amines, in symptom provocation is discussed. The known effects of lactose deficiency and fructose malabsorption are reviewed. The FODMAP concept (fermentable oligo-, di-, monosaccharides and polyols) is presented in more detail and recent studies on pathophysiological effects of FODMAP constituents and of therapeutic effects of a low FODMAP diet on symptoms in patients with irritable bowel syndrome are discussed. Finally, studies on the new disorder non-celiac gluten sensitivity (NCGS) are summarized and the state of the discussion whether wheat intolerance is due to gluten or the grains is given.

Fructose intolerance/malabsorption and recurrent abdominal pain in children.

MA Escobar Jr, D Lustig, BM Pflugeisen. J Pediatr Gastroenterol Nutr. 2014;58(4):498–501 The goal of this study was to determine the incidence of fructose malabsorption in children who present with chronic or recurrent abdominal pain and whether a low-fructose diet improves their symptoms. Study participants were recruited after retrospective chart review of consecutive patients from 2007 to 2009 without a specific etiology identified for chronic abdominal pain. A total of 222 children ages 2 to 19 years (64% female) who had …

Optimal Testing for Diagnosis of Fructose Intolerance: Over-dosage Leads to False Positive Intolerance Test.

TO THE EDITOR: We read with interest the recent article by Goebel-Stengel et al 1 and wish to express our appreciation and enthusiasm for their work on small intestinal bacterial overgrowth (SIBO) and carbohydrate intolerance in patients with irritable bowel syndrome (IBS). However, we have significant concerns regarding their methodology and basis for diagnosis of fructose intolerance. Goebel-Stengel et al 1 used a supra-physiologic dose of 50 g fructose in 200 mL water for performing the fructose breath test. The rationale for this high dose is unclear, and whether healthy controls from their population can fully absorb 50 g dose of fructose has not been reported by these authors. If the test was positive, an additional breath test was performed with 25 g in 100 mL water. Patients were then classified as subjects with moderate symptomatic fructose malabsorption if they were positive with 50 g dose and negative with 25 g dose, and severe fructose malabsorbers as patients who were positive at both doses. Since almost all healthy subjects can absorb up to 25 g of fructose, and 70% malabsorb at 50 g dose, 2 it is unclear why the authors chose a 50 g fructose dose. Authors have partially justified this dose stating that daily consumption of fructose may be higher than 25 g, and fructose concentration less than 50 g has low yield. These assumptions are incorrect. Whilst it is possible that patients may consume up to 50 g fructose/day, this amount is usually not ingested all at once. Because the maximum absorptive capacity for a single dose is 25 g for healthy subjects, a higher dose will give a higher and false positive diagnosis of fructose malabsoption/ intolerance. This finding may lead to incorrect diagnosis and unnecessary restriction of fructose products in diet, when in fact the subject may have normal fructose absorption capacity. Also performing 2 tests for identifying fructose intolerance seems impractical and should be avoided. Also, we disagree with recommendation that fructose breath test should be performed only for research purposes, 3 as doing so will deprive patients of an important diagnosis. Also many of them will be falsely labelled as IBS. It was somewhat surprising that the authors did not reference the only well controlled, dose-response, fructose absorption study in healthy humans. 4 We believe that the ideal test dose for patients with suspected fructose intolerance is 25 g, and breath samples should be obtained every 30 minutes for 3 hours, and analyzed for H2 and CH4 levels. 4 This standardized diagnostic approach for fructose breath test should facilitate better characterization of fructose malabsorption in patients with unexplained gas and bloating, and this has been shown to be clinically useful in a large group of 429 consecutive patients. 5

Positive or Negative Fructose Breath Test Results do not Predict Response to Fructose Restricted Diet in Children with Recurrent Abdominal Pain: Results from a Prospective Randomized Trial

To perform a prospective, blinded, randomized interventional trial in patients with recurrent abdominal pain. The primary endpoint was to determine the abdominal pain intensity after 2 weeks of fructose restricted diet. Secondary endpoints were changes of pain frequency and a secondary symptom score (SSS). 103 individuals with recurrent abdominal pain for more than 3 months were randomized. 51 patients were allocated to group A (diet) and 52 to group B (no diet). 2 weeks later the patients underwent hydrogen breath test and were assigned to the test positive or negative group to identify patients with fructose malabsorption. 2 weeks after intervention the pain score decreased significantly from a median 5.5 in group A to 4 and did not change significantly in group B (5.3 to 5). In group A both patients with positive and negative breath tests had a significant lower pain score (-2 and -1.75, respectively). Frequency of abdominal pain decreased in both groups but without significant difference, SSS improved only in group A from median 6 to 3.5. Positive breath test was no predicting factor, neither was abdominal pain during the test. Fructose restricted diet in children and adolescents with recurrent abdominal pain may be of benefit to improve both abdominal pain symptoms and other secondary symptoms. Since a negative breath test result does not exclude a positive response to fructose restriction, the hydrogen breath test does not seem to be the appropriate diagnostic mean to predict the response to the diet.

Evaluation of healthy and sensory indexes of sweetened beverages using an electronic tongue

Overconsumption of sugar-sweetened beverages may increase the risk of health problems and so, the evaluation of their glycemic load and fructose-intolerance level is essential since it may allow establishing possible relations between physiologic effects of sugar-rich beverages and health. In this work, an electronic tongue was used to accurately classify beverages according to glycemic load (low, medium or high load) as well to their adequacy for people suffering from fructose malabsorption syndrome (tolerable or not): 100% of correct classifications (leave-one-out cross-validation) using linear discriminant models based on potentiomentric signals selected by a meta-heuristic simulated annealing algorithm. These results may be partially explained by the electronic tongue’s capability to mimic the human sweetness perception and total acid flavor of beverages, which can be related with glycemic load and fructose-intolerance index. Finally, the E-tongue was also applied to quantify, accurately, healthy and sensory indexes using multiple linear regression models (leave-one-out cross-validation: Radj>0.99) in the following dynamic ranges: 4.7<glycemic load≤30; 0.4<fructose intolerance index≤1.5; 32<sweetness perception<155; 1.3<total acid flavor, gL−1<8.3; and, 5.8<well-balanced flavor≤74. So, the proposed electronic tongue could be used as a practical, fast, low-cost and green tool for beverage’s healthy and sensory evaluation.

Fructose malabsorption is not uncommon among patients with irritable bowel syndrome in India: a case-control study.

Fructose malabsorption (FM) is reported in 38 % to 75 % patients with irritable bowel syndrome (IBS). Most of these studies, however, had limitations due to use of variable dose of fructose, small sample size, and lack of control population. Moreover, there is no study on this issue from India. Hence, in this prospective study, we evaluated the frequency of FM on an adequately powered sample of patients with IBS and healthy controls (HC) from India. Ninety-seven patients with IBS (diagnosed using Rome III criteria) and 41 healthy controls were evaluated for FM by fructose hydrogen breath test (FHBT) using 25 g fructose. Persistent rise (at least two readings) in breath hydrogen 20 parts per million (PPM) above basal was considered diagnostic of FM. Patients and controls were comparable in age (37 years [21-66] vs. 33 years [15-56]; p = 0.1) and gender (76/97 [78.4 %] vs. 29/41 [70.7 %] male; p = 0.3). Of 70 patients reporting data on Bristol's stool forms, 10 (14 %), 43 (61 %), and 17 (25 %) had constipation, diarrhea predominant and unclassified IBS (Asian classification), respectively. Patients with IBS more often had FM than controls on FHBT (14/97 [14.4 %] vs. 1/41 [2.4 %]; p = 0.04). Patients with FM more often had diarrhea-predominant IBS than those without FM (10/11 [91 %] vs. 33/59 [56 %]; p = 0.02). Though FM was not very common among Indian patients with IBS, it was higher among them than controls. Patients with FM more often had diarrhea-predominant IBS.

Malabsorption of fermentable oligo-, di-, or monosaccharides and polyols (FODMAP) as a common cause of unclear abdominal discomfort

Carbohydrate malabsorption is a frequent but underestimated cause of unexplained gastrointestinal symptoms like meteorism, flatulence, pain and diarrhea. By means of hydrogen and/or methane breath test after ingestion of the respective carbohydrate it can be identified and diagnosed easily, fast and reliably by successful nutritional therapy. Besides the well known complaints caused by lactose and fructose malabsorption, other fermentable oligo-, di-, or monosaccharides and polyols (akronym: FODMAP) can cause abdominal discomfort and IBS-like symptoms. In addition to lactose (dairy products) and fructose (apples, pears, mango, watermelon), FODMAPs comprise galactans (legumes), fructans (wheat, onions, garlic, artichoke) and the artificial sweeteners sorbitol, mannitol, maltitol and xylitol (sugar free candy, light products). A general restriction of all FODMAP components can be beneficial in relieving symptoms and improving quality of life in patients with functional gastrointestinal complaints.

Sa1179 Prevalence of Fructose Malabsorption in Patients With Irritable Bowel Syndrome After Excluding Small Intestinal Bacterial Overgrowth

Sa1179 Prevalence of Fructose Malabsorption in Patients With Irritable Bowel Syndrome After Excluding Small Intestinal Bacterial Overgrowth

Fructose Malabsorption in Patients With Irritable Bowel Syndrome-like Symptoms: What Is the Role in the Pathogenesis and Clinical Implication?

Fructose Malabsorption in Patients With Irritable Bowel Syndrome-like Symptoms: What Is the Role in the Pathogenesis and Clinical Implication?

Symptomatic fructose malabsorption in irritable bowel syndrome: A prospective study.

Fructose can trigger or worsen symptoms in irritable bowel syndrome (IBS) patients. The aim of this study was to determine the prevalence of symptomatic fructose malabsorption in IBS patients and to test whether the patient's characteristics can help to detect a fructose malabsorption. Ninety Rome III IBS patients (predominant diarrhoea (IBS-D): 31%, predominant constipation (IBS-C): 18%, mixed type (IBS-M): 51%) were included prospectively. After exclusion of a small intestinal bacterial overgrowth by a glucose breath test, fructose malabsorption was assessed by a five-hour breath test, with symptom monitoring, after a 25 g load of fructose. An increase of more than 20 ppm of hydrogen (H2) or methane (CH4) levels in the exhaled air led to the diagnosis of malabsorption. Fructose test was abnormal in 20/90 patients among whom only 35% were intolerant, with a simultaneous rise of H2/CH4 levels and the onset of abdominal discomfort or diarrhoea. IBS characteristics were not predictive even if young (p = 0.031) and male IBS patients (p = 0.029) were at higher risk of malabsorption. At variance, 18 additional patients experienced intestinal symptoms during the test despite normal fructose absorption. After a 25 g fructose load, symptomatic fructose malabsorption and intolerance without malabsorption were detected in 22% and 28% of IBS patients respectively.

Fructose Malabsorption in Patients With Irritable Bowel Syndrome-like Symptoms: What Is the Role in the Pathogenesis and Clinical Implication?

Article: Unclear abdominal discomfort: pivotal role of carbohydrate malabsorption Goebel-Stengel M, Stengel A, Schmidtmann M, van der Voort I, Kobelt P, Mönnikes H.

Unclear abdominal discomfort: pivotal role of carbohydrate malabsorption.

Background/AimsCarbohydrate malabsorption is frequent in patients with functional gastrointestinal disorders and in healthy volunteers and can cause gastrointestinal symptoms mimicking irritable bowel syndrome (IBS). The aim of this study was to investigate the prevalence of symptomatic lactose and fructose malabsorption in a large population of patients with IBS-like symptoms based on Rome II criteria.MethodsPatients with unclear abdominal discomfort (n = 2,390) underwent lactose (50 g) and fructose (50 g) hydrogen (H2) breath tests and depending on the results further testing with 25 g fructose or 50 g glucose, or upper endoscopy with duodenal biopsies. Additionally, this population was investigated regarding the prevalence of small intestinal bacterial overgrowth (SIBO) based on glucose breath test and celiac disease.ResultsOf the 2,390 patients with IBS-like symptoms, 848 (35%) were symptomatic lactose malabsorbers and 1,531 (64%) symptomatic fructose malabsorbers. A combined symptomatic carbohydrate malabsorption was found in 587 (25%) patients. Severe fructose malabsorbers (pathologic 25 g fructose test) exhaled significantly higher H2 concentrations in the 50 g test than patients with negative 25 g fructose test (P < 0.001). Out of 460/659 patients with early significant H2 increase in the lactose and fructose test who underwent a glucose breath test, 88 patients had positive results indicative of SIBO and they were significantly older than patients with negative test result (P < 0.01). Celiac disease was found in 1/161 patients by upper endoscopy.ConclusionsCarbohydrate malabsorption is a frequent but underestimated condition in patients with IBS-like symptoms although diagnosis can be easily confirmed by H2 breath testing.

Fructose consumption and its health implications; fructose malabsorption and nonalcoholic fatty liver disease

Fructose intake has increased considerably in recent years, especially in the form high fructose corn syrup, due its high sweetening power. Several studies have associated high intake of fructose to metabolic alterations, as nonalcoholic fatty liver disease and fructose malabsorption, among other pathologies. This review aims to update about the effect of high intake of fructose in the liver and intestine, mainly associated with processed foods with added fructose. An updated literature search was conducted using databases (Pubmed, Scopus and SciELO), selecting articles published after the year 2000, resulting from the keywords "fructose intake, fructose intolerance, nonalcoholic fatty liver and fructose, fructose malabsorption" Of 735 articles initially retrieved, 78 met the inclusion criteria. Fructose consumption has increased in recent decades, especially due to increased consumption of sweetened beverages and processed foods with added fructose. High fructose intake has been associated to pathologies as NAFLD and fructose malabsorption.

Correction Required

No one would doubt the fact that the number of patients seeking help for carbohydrate malabsorption problems has substantially risen over recent years. When asked, many patients express the opinion that they have an intolerance to fructose, whereas just a few questions regarding clinical symptoms will clarify that what actually affects them is a far more harmless fructose resorption disorder. The authors explicitly caution in their article (1) that “gastrointestinal malabsorption of fructose should not be confused with hereditary fructose intolerance.” But the term “gastrointestinal carbohydrate intolerance,” as used in the abstract, does not exactly help clarify matters. The tables and figures show substantial gaps and errors when mentioning congenital defects in the monosaccharide metabolism, and these defects do not in any case relate symptomatically to malabsorptions in terms of the differential diagnosis. Although “galactosemia” refers to three congenital defects, galactokinase deficiency is the only one listed. This is a defect common in persons of Sinti/Romany origin and manifests as cataract development. The only embarrassing thing is that since 2002, all neonates in Germany are examined for another type of galactosemia: galactose 1 phosphate uridyltransferase deficiency, the so called classic galactosemia. It would be highly desirable for this information, or a correction, to be added to this article post hoc.