Fructose intolerance in children presenting with abdominal pain

Fructose malabsorption and fructan malabsorption are associated in patients with irritable bowel syndrome

BACKGROUND

Food malabsorption and intolerance is implicated in gastrointestinal symptoms among patients with irritable bowel syndrome (IBS). Key triggers include fructose and fructan. Prior studies examined fructose and fructan malabsorption separately in IBS patients. None have concurrently assessed both within the same patient group. We aimed to investigate the association between fructose and fructan malabsorption in the same patients with IBS using hydrogen breath testing (HBT).

METHODS

We retrospectively identified patients with IBS who underwent fructose and fructan HBTs and abstracted their results from the electronic medical record. Fructose and fructan HBTs were performed by administering a 25 g fructose solution or 10 g fructan solution, followed by breath hydrogen readings every 30 min for 3 h. Patients were positive for fructose or fructan malabsorption if breath hydrogen levels exceeded 20 ppm.

RESULTS

Of 186 IBS patients, 71 (38.2%) were positive for fructose malabsorption and 91 (48.9%) were positive for fructan malabsorption. Of these patients, 42 (22.6%) were positive for fructose malabsorption and fructan malabsorption. Positive fructose HBT readings were significantly associated with positive fructan HBT readings (p = 0.0283). Patients positive for fructose malabsorption or fructan malabsorption had 1.951 times higher odds of testing positive for the other carbohydrate.

CONCLUSIONS

Our results reveal a clinically significant association between fructose malabsorption and fructan malabsorption in patients with IBS. Fructan malabsorption should be assessed in patients with fructose malabsorption, and vice versa. Further studies are required to identify the mechanisms underlying our findings.

Clinical and Metabolomic Effects of Lactiplantibacillus plantarum and Pediococcus acidilactici in Fructose Intolerant Patients

Fructose intolerance (FI) is a widespread non-genetic condition in which the incomplete absorption of fructose leads to gastro-intestinal disorders. The crucial role of microbial dysbiosis on the onset of these intolerance symptoms together with their persistence under free fructose diets are driving the scientific community towards the use of probiotics as a novel therapeutic approach. In this study, we evaluated the prevalence of FI in a cohort composed of Romanian adults with Functional Grastrointestinal Disorders (FGIDs) and the effectiveness of treatment based on the probiotic formulation EQBIOTA^® (Lactiplantibacillus plantarum CECT 7484 and 7485 and Pediococcus acidilactici CECT 7483). We evaluated the impact of a 30-day treatment both on FI subjects and healthy volunteers. The gastrointestinal symptoms and fecal volatile metabolome were evaluated. A statistically significant improvement of symptoms (i.e., bloating, and abdominal pain) was reported in FI patient after treatment. On the other hand, at the baseline, the content of volatile metabolites was heterogeneously distributed between the two study arms, whereas the treatment led differences to decrease. From our analysis, how some metabolomics compounds were correlated with the improvement and worsening of clinical symptoms clearly emerged. Preliminary observations suggested how the improvement of gastrointestinal symptoms could be induced by the increase of anti-inflammatory and protective substrates. A deeper investigation in a larger patient cohort subjected to a prolonged treatment would allow a more comprehensive evaluation of the probiotic treatment effects.

No Correlation between Positive Fructose Hydrogen Breath Test and Clinical Symptoms in Children with Functional Gastrointestinal Disorders: A Retrospective Single-Centre Study

Fructose malabsorption is regarded as one of the most common types of sugar intolerance. However, the correlation between gastrointestinal symptoms and positive results in fructose hydrogen breath tests (HBTs) remains unclear. The aim of this study was to assess the clinical importance of positive fructose HBT by correlating the HBT results with clinical features in children with various gastrointestinal symptoms. Clinical features and fructose HBT results were obtained from 323 consecutive children (2–18 years old, mean 10.7 ± 4.3 years) that were referred to the Tertiary Paediatric Gastroenterology Centre and diagnosed as having functional gastrointestinal disorders. A total of 114 out of 323 children (35.3%) had positive HBT results, of which 61 patients were females (53.5%) and 53 were males (46.5%). Children with positive HBT were significantly younger than children with negative HBT (9.0 vs. 11.6 years old; p < 0.001). The most frequent symptom among children with fructose malabsorption was recurrent abdominal pain (89.5%). Other important symptoms were diarrhoea, nausea, vomiting, and flatulence. However, no correlation between positive fructose HBT results and any of the reported symptoms or general clinical features was found. In conclusion, positive fructose HBT in children with functional gastrointestinal disorders can be attributed to their younger age but not to some peculiar clinical feature of the disease.

Methane breath tests and blood sugar tests in children with suspected carbohydrate malabsorption

Carbohydrate malabsorption and subsequent gastrointestinal symptoms are a common clinical problem in pediatrics. Hydrogen (H₂) and methane (CH₄) breath tests are a cheap and non-invasive procedure for diagnosing fructose and lactose malabsorption (FM/LM) but test accuracy and reliability as well as the impact of non-hydrogen producers (NHP) is unclear. CH₄ breath tests (MBT), blood sugar tests (BST) and clinical symptoms were compared with H₂ breath tests (HBT) for FM/LM. 187/82 tests were performed in children (2 to 18 years) with unclear chronic/recurrent abdominal pain and suspected FM/LM. In FM and LM, we found a significant correlation between HBT and MBT/BST. In LM, MBT differentiated most of the patients correctly and BST might be used as an exclusion test. However, additional MBT and BST had no diagnostic advantage in FM. NHP still remain a group of patients, which cannot be identified using the recommended CH₄ cut-off values in FM or LM. Reported symptoms during breath tests are not a reliable method to diagnose FM/LM. Overall a combined test approach might help in diagnosing children with suspected carbohydrate malabsorption.

Global Dietary Patterns and Functional Gastrointestinal Disorders

Functional Gastrointestinal Disorders (FGIDs) are common. In the United States alone, approximately 25 million Americans are estimated to have at least one FGID. Nonpharmacological treatment options include psychological/behavioral approaches, and dietary interventions that can vary across countries. The aim of this review is to evaluate the available evidence for dietary interventions for the treatment of childhood FGIDs amongst various cultures and regions of the world. This review includes clinical trials of dietary therapies for the treatment of FGIDs in children posted on or before 13 July 2020 in PubMed. Overall, the consensus view suggests that the westernization of diets is linked to the development of FGIDs, and diets low in Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (FODMAPs) may reduce abdominal symptoms. However, more work is needed to confirm these findings.

'Rapid transit' constipation in children: a possible genesis for irritable bowel syndrome

Children with chronic idiopathic constipation (CIC) often end up at the surgeon when medical treatments have failed. This opinion piece discusses a recently described pattern of CIC called 'Rapid transit constipation (RTC)' first identified in 2011 as part of surgical workup. RTC was identified using a nuclear medicine gastrointestinal transit study (NMGIT or nuclear transit study) to determine the site of slowing within the bowel and to inform surgical treatment. Unexpectedly, we found that RTC occured in 29% of 1000 transit studies in a retrospective audit. Irritable bowel syndrome (IBS) occurs in 7-21% of the population, with a higher prevalence in young children and with constipation type dominating in the young. While 60% improve with time, 40% continue with symptoms. First-line therapy for IBS in adults is a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols which reduces symptoms in > 70% of patients. In children with functional gastrointestinal disorders, fructose intolerance occurs in 35-55%. Reducing fructose produced significant improvement in 77-82% of intolerant patients. In children with RTC and a positive breath test upon fructose challenge, we found that exclusion of fructose significantly improved constipation, abdominal pain, stool consistency and decreased laxative use. We hypothesise that positive breath tests and improvement of pain and bowel frequency with sugar exclusion diets in RTC suggest these children have IBS-C. These observations raise the possibility that many children with CIC could be treated by reducing fructose early in their diet and this might prevent the development of IBS in later life.

Roles of Lactose and Fructose Malabsorption and Dietary Outcomes in Children Presenting with Chronic Abdominal Pain

Intolerance to lactose or fructose is frequently diagnosed in children with chronic abdominal pain (CAP). However, the causal relationship remains a matter of discussion. A cohort of 253 patients, aged 7–12 years, presenting with unexplained CAP received standardized diagnostics. Additional diagnostic tests were performed based on their medical history and physical and laboratory investigations. Fructose and lactose hydrogen breath tests (H₂BT) as well as empiric diagnostic elimination diets were performed in 135 patients reporting abdominal pain related to the consumption of lactose or fructose to evaluate carbohydrate intolerance as a potential cause of CAP. Carbohydrate malabsorption by H2BT was found in 55 (41%) out of 135 patients. An abnormal increase in H2BT was revealed in 30% (35/118) of patients after fructose consumption and in 18% (20/114) of patients after lactose administration. Forty-six percent (25/54) reported pain relief during a diagnostic elimination diet. In total, 17 patients had lactose malabsorption, 29 fructose malabsorption, and nine combined carbohydrate malabsorption. Carbohydrate intolerance as a cause of CAP was diagnosed at follow-up in only 18% (10/55) of patients with malabsorption after the elimination of the respective carbohydrate. Thus, carbohydrate malabsorption appears to be an incidental finding in children with functional abdominal pain disorders, rather than its cause. Therefore, testing of carbohydrate intolerance should only be considered in children with a strong clinical suspicion and with the goal to prevent long-term unnecessary dietary restrictions in children suffering from CAP.

Low FODMAPs diet for functional abdominal pain disorders in children: critical review of current knowledge

OBJECTIVE

This narrative review aimed to provide practitioners a synthesis of the current knowledge on the role of a low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet in reducing symptoms associated with functional abdominal pain disorders in children. This review is focused on the pathophysiology, efficacy and criticism of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet in children.

SOURCES

Cochrane Database, Pubmed and Embase were searched using specific terms for Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet interventions and functional abdominal pain disorders.

SUMMARY OF THE FINDINGS

In children, only one Randomized Control Trial and one open-label study reported positive results of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet; one Randomized Control Trial showed exacerbation of symptoms with fructans in children with Irritable Bowel Syndrome; no effect was found for the lactose-free diet whilst fructose-restricted diets were effective in 5/6 studies.

CONCLUSIONS

In children there are few trials evaluating low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols in functional abdominal pain disorders, with encouraging data on the therapeutic efficacy particularly of fructose-restricted diet. Additional efforts are still needed to fill this research gap and clarify the most efficient way for tailoring dietary restrictions based on the patient's tolerance and/or identification of potential biomarkers of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols efficacy, to maintain nutritional adequacy and to simplify the adherence to diet by labeling Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols content in commercial products.

Fructose malabsorption in asymptomatic children and in patients with functional chronic abdominal pain: a prospective comparative study

The objective of this prospective cohort study was to compare fructose malabsorption in patients with functional chronic abdominal pain and in healthy children. The sample was divided into two groups: asymptomatic children and pain-predominant functional gastrointestinal disorders according to the Rome IV criteria. All children were tested for fructose malabsorption by a standardized breath hydrogen test. Hydrogen and methane were measured and the test was presumed positive when it exceeded 20 ppm above baseline. If positive, patients were given a low-fructose diet and the response was evaluated. One hundred five children were included (34 healthy children, 71 with functional chronic abdominal pain), with similar demographic characteristics in both groups (35.2% male, age 9.5 ± 2.8 years). Hydrogen levels in breath were tested through a hydrogen test for fructose demonstrating malabsorption in 58.8% of healthy children (95%CI 40.8%-76.8%) and in 40.8% of children with chronic abdominal pain (95%CI 28.7%-53.0%), removing those who had bacterial overgrowth. Twenty-one of 31 patients with symptoms and a positive test (72.4%) reported an improvement on a low-fructose diet.Conclusion: Fructose malabsorption is more common in asymptomatic children than in patients with chronic abdominal pain. Better standardized test conditions are necessary to improve accuracy of diagnosis before using this test in clinical practice. What is Known: • Although fructose malabsorption is believed to be related with chronic abdominal pain, high-quality evidence is lacking. • Concerns have raised regarding the use of breath hydrogen test for fructose malabsorption in children with chronic abdominal pain. What is New: • Fructose malabsorption is not more common in children with pain-predominant functional gastrointestinal disorders than in asymptomatic children. • Improvement in symptoms with low-fructose diet may indicate that, although patients with pain-predominant functional gastrointestinal disorders did not have a higher percentage of malabsorption, they had greater fructose intolerance.

Low FODMAP diet in children and adolescents with functional bowel disorder: A clinical case note review

Background and Aims

Functional bowel disorders (FBD), such as irritable bowel syndrome (IBS), are increasingly more common in children and affect up to 20% of children. The etiology is multifactorial with no clear organic cause. Symptoms are recurrent and are associated with a reduced quality of life, school absences, and psychological challenges. Treatment options are variable. FODMAPs are short‐chained carbohydrates, poorly absorbed by the gastrointestinal tract due to their increased osmotic activity and excess gas production from the bacterial fermentation process. There is a paucity of data examining dietary interventions that restrict carbohydrates in children with IBS. The aim of this study was to examine the use of the low FODMAP diet (LFD) in children with an FBD.

Methods

A retrospective clinical case note review of children with an FBD managed with an LFD was undertaken. Anthropometry and clinical data were collected by a pediatric gastroenterology dietitian. An IBS satisfaction survey was used to assess diet outcomes. Statistical analyses were completed using Excel.

Results

Of the 29 children included in this study, complete resolution of gastrointestinal symptoms was observed for 11 of 12 (92%) of those with bloating, 13 of 15 (87%) of those with diarrhea, and 17 of 22 (77%) of those with abdominal pain. Twenty‐three (79%) participants reported an improvement of symptoms. Fructans were the most common symptom‐causing carbohydrate.

Conclusion

The LFD is a useful dietary treatment strategy for children with FBD. This study adds to the small body of evidence supporting FODMAP dietary interventions in children with FBD. Further prospective studies are required.

Dietary Habits and Abdominal Pain-related Functional Gastrointestinal Disorders: A School-based, Cross-sectional Analysis in Greek Children and Adolescents

Background/Aims

The abdominal pain-related functional gastrointestinal disorders (AP-FGIDs) affect a significant proportion of the pediatric population and consist 1 of the most frequent causes for seeking medical advice. In this study, we aimed to assess the relation of dietary habits with the likelihood of AP-FGIDs.

Methods

This was a school-based, cross-sectional study approved by the Greek Government authorities, after obtaining informed consent by the legal representatives of the children. Diagnoses of AP-FGIDs were based on the Greek official translation of the Rome III questionnaire. Demographic, socioeconomic and dietary data were collected through self-reporting or parent-reporting questionnaires. Associations between the probability of AP-FGIDs and dietary practices were assessed after adjusting for known confounders through a multiple logistic regression analysis.

Results

A total of 1365 children (147 AP-FGIDs and 1218 controls, 52.4% females, mean age: 12.8 ± 2.8 years) were included. Multiple regression analysis identified the following statistically significant confounders: victimization, the presence of a person with a severe health problem at home, female sex, engaging in limited physical exercise, and living in a single adult family. Subsequently, logistic regression, adjusted for the abovementioned confounders, showed that reduced fish and increased junk food consumption were related to a higher likelihood of AP-FGIDs.

Conclusions

Children with AP-FGIDs report excessive junk-food and reduced fish intake compared to controls. Further studies are needed in order to clarify the nature of this observation.

The Use of Dietary Interventions in Pediatric Patients

Complementary and alternative treatment approaches are becoming more common among children with chronic conditions. The prevalence of CAM use among US adults was estimated to be around 42% in 2015 and around 44% to 50% among adults with neurologic disorders. Studies demonstrate that children with certain chronic illnesses such as asthma, cancer, genetic disorders, attention-deficit/hyperactivity disorder (ADHD), and other neurodevelopmental disorders are treated with complementary and alternative treatments at higher rates. Dietary therapies are gaining increasing popularity in the mainstream population. Although the majority of "fad" diets do not have enough supporting evidence, some dietary therapies have been utilized for decades and have numerous published studies. The objective of this review is to describe the dietary interventions used in children with the specific chronic conditions, to evaluate their efficacy based on published data and to encourage pharmacist involvement in the management and care of such patients.

Update on Dietary Management of Childhood Functional Abdominal Pain Disorders

Diet plays a significant role for children with functional abdominal pain disorders. A large majority of these children identify at least 1 food that exacerbates their symptoms. Malabsorbed carbohydrates may have both direct and microbiome-mediated physiologic effects. There are several factors associated with carbohydrate symptom generation, including (1) the amount ingested, (2) ingestion with a meal, (3) small intestinal enzymatic activity, (4) consuming the carbohydrate with microorganisms capable of breaking down the carbohydrate, (5) the gut microbiome, and (6) host factors. Therapies include carbohydrate (single and/or comprehensive) restriction, selective prebiotic and/or enzyme supplementation. Fiber supplementation may also be beneficial.

Intestinal fructose malabsorption is associated with increased lactulose fermentation in the intestinal lumen

OBJECTIVE

To study fructose malabsorption in children and adolescents with abdominal pain associated with functional gastrointestinal disorders. As an additional objective, the association between intestinal fructose malabsorption and food intake, including the estimated fructose consumption, weight, height, and lactulose fermentability were also studied.

METHODS

The study included 31 patients with abdominal pain (11 with functional dyspepsia, 10 with irritable bowel syndrome, and 10 with functional abdominal pain). The hydrogen breath test was used to investigate fructose malabsorption and lactulose fermentation in the intestinal lumen. Food consumption was assessed by food registry. Weight and height were measured.

RESULTS

Fructose malabsorption was characterized in 21 (67.7%) patients (nine with irritable bowel syndrome, seven with functional abdominal pain, and five with functional dyspepsia). Intolerance after fructose administration was observed in six (28.6%) of the 21 patients with fructose malabsorption. Fructose malabsorption was associated with higher (p<0.05) hydrogen production after lactulose ingestion, higher (p<0.05) energy and carbohydrate consumption, and higher (p<0.05) body mass index z-score value for age. Median estimates of daily fructose intake by patients with and without fructose malabsorption were, respectively, 16.1 and 10.5g/day (p=0.087).

CONCLUSION

Fructose malabsorption is associated with increased lactulose fermentability in the intestinal lumen. Body mass index was higher in patients with fructose malabsorption.

Dietary exclusion of fructose and lactose after positive breath tests improved rapid-transit constipation in children

Aims

Exclusion of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) from the diet is effective in alleviating symptoms of irritable bowel syndrome (IBS) in adults. Rapid‐transit constipation (RTC) is a recently discovered subset of chronic constipation and has been linked to food intolerance. The aim of this study was to audit the effect of specific FODMAP elimination diets in children with RTC.

Methods

This was an audit of children presenting to a tertiary children's hospital surgeon with refractory chronic constipation who had rapid transit in the proximal colon on nuclear imaging; had hydrogen/methane breath tests for fructose, lactose, and/or sorbitol intolerance; and were advised to exclude positive sugar under clinical supervision. Patients filled in a questionnaire rating severity of constipation, abdominal pain, and pain on defecation with a visual analogue scale (VAS, 0 = none, 10 = high) and stool consistency for 6 months before and after dietary exclusion.

Results

In responses from 29 children (5–15 years, 21 males), 70% eliminated fructose, and 40% eliminated lactose. There was a significant reduction in the severity of constipation (VAS mean ± SEM, pre 5.8 ± 0.5 vs post 3.3 ± 0.6, P < 0.0001), abdominal pain (5.1 ± 0.6 vs 2.8 ± 0.5, P = 0.0004), pain on defecation (5.8 ± 0.6 vs 2.6 ± 0.5, P < 0.0001), and increase in stool wetness (Bristol Stool Scale pre 3.3 ± 0.3 vs post 3.9 ± 0.2, P = 0.004).

Conclusion

Children with RTC showed significant improvements in constipation and pain after excluding the sugar indicated by positive breath tests, suggesting that specific sugar‐exclusion diets may have a role in the management of RTC in children.

Does a low FODMAPs diet reduce symptoms of functional abdominal pain disorders? A systematic review in adult and paediatric population, on behalf of Italian Society of Pediatrics

Background

Despite the rising of the Functional Gastrointestinal Disorders (FGIDs)’ incidence in the last years, the etio-pathogenesis of FGIDs remains unclear. The diet seems to play an important role in these disorders. Indeed, at least two thirds of adult patients with Irritable Bowel Syndrome (IBS) and of children with FGIDs perceive their GI symptoms to be food-related. In particular, in the last years, more interest has been focused in the low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyol (FODMAPs) diet.

Aims

To provide a systematic review on the efficacy of a low FODMAPs diet in reducing symptoms associated with functional abdominal pain disorders.

Methods

Cochrane Library, MEDLINE (via Pubmed), and EMBASE databases from inception to June 2017 were searched. We included randomized controlled trials (RCTs), prospective and retrospective studies, systematic reviews and meta-analyses, reporting the efficacy of the FODMAPs diet intervention in FGIDs patients.

Results

Nineteen studies were eligible. A FODMAPs-restricted diet is beneficial in 12/13 intervention trials. The low FODMAPs diet improves overall GI symptoms, especially abdominal pain and bloating. In children, only one study reported positive results of a low FODMAPs diet. No effect was found for the lactose free diet whilst fructose-restricted diet was effective in 3/4 studies. The duration of the intervention was very different among the studies, ranging from 2 days to 16 months, and from 3 and 9 weeks for the RCTs. The majority of the trials presented differences in symptoms scoring scales, diet, food diaries, and food frequencies questionnaire.

Conclusions

The FODMAPs-restricted diet may be an effective dietary intervention for reducing IBS symptoms in adults. In children, there are promising data, although only one randomized double-blind study exists and further data are needed to better clarify the role of FODMAPs and fructose-restricted diet in IBS. The current evidence does not support the use of a lactose-restricted diet in children with FGIDs.

Intestinal Absorption of Fructose

Increased understanding of fructose metabolism, which begins with uptake via the intestine, is important because fructose now constitutes a physiologically significant portion of human diets and is associated with increased incidence of certain cancers and metabolic diseases. New insights in our knowledge of intestinal fructose absorption mediated by the facilitative glucose transporter GLUT5 in the apical membrane and by GLUT2 in the basolateral membrane are reviewed. We begin with studies related to structure as well as ligand binding, then revisit the controversial proposition that apical GLUT2 is the main mediator of intestinal fructose absorption. The review then describes how dietary fructose may be sensed by intestinal cells to affect the expression and activity of transporters and fructolytic enzymes, to interact with the transport of certain minerals and electrolytes, and to regulate portal and peripheral fructosemia and glycemia. Finally, it discusses the potential contributions of dietary fructose to gastrointestinal diseases and to the gut microbiome.

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

BACKGROUND

Limited valid data are available regarding the association of fructose-induced symptoms, fructose malabsorption, and clinical symptoms.

AIM

To 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.

METHODS

A 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.

RESULTS

The 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.

CONCLUSIONS

Fructose-induced symptoms but not fructose malabsorption are related to increased abdominal symptoms and have distinct timing patterns.

Excess free fructose, high-fructose corn syrup and adult asthma: the Framingham Offspring Cohort

There is growing evidence that intakes of high-fructose corn syrup (HFCS), HFCS-sweetened soda, fruit drinks and apple juice - a high-fructose 100 % juice - are associated with asthma, possibly because of the high fructose:glucose ratios and underlying fructose malabsorption, which may contribute to enteral formation of pro-inflammatory advanced glycation end products, which bind receptors that are mediators of asthma. Cox proportional hazards models were used to assess associations between intakes of these beverages and asthma risk, with data from the Framingham Offspring Cohort. Diet soda and orange juice - a 100 % juice with a 1:1 fructose:glucose ratio - were included for comparison. Increasing intake of any combination of HFCS-sweetened soda, fruit drinks and apple juice was significantly associated with progressively higher asthma risk, plateauing at 5-7 times/week v. never/seldom, independent of potential confounders (hazard ratio 1·91, P<0·001). About once a day consumers of HFCS-sweetened soda had a 49 % higher risk (P<0·011), moderate apple juice consumers (2-4 times/week) had a 61 % higher risk (P<0·007) and moderate fruit drink consumers had a 58 % higher risk (P<0·009), as compared with never/seldom consumers. There were no associations with diet soda/orange juice. These associations are possibly because of the high fructose:glucose ratios, and fructose malabsorption. Recommendations to reduce consumption may be inadequate to address asthma risk, as associations are evident even with moderate intake of these beverages, including apple juice - a 100 % juice. The juice reductions in the US Special Supplemental Nutrition Program for Women, Infants, and Children in 2009, and the plateauing/decreasing asthma prevalence (2010-2013), particularly among non-Hispanic black children, may be related. Further research regarding the consequences of fructose malabsorption is needed.

Fructose Intolerance: Cause or Cure of Chronic Functional Constipation

Functional constipation is a common occurrence in the pediatric population. The link between fructose ingestion and constipation is obscure due to a lack of published data. In this article, we discuss the relationship of fructose tolerance and the development of constipation via a literature review and our single-center experience. A literature review of constipation and fructose ingestion was performed using PubMed. A retrospective chart review from the pediatric gastroenterology clinic, January 2012 to December 2015, was completed, with attention to the relationship of fructose intolerance and its clinical presentations. There were 367 patients who underwent the fructose breath hydrogen test (FBHT), out of which 208 patients had fructose intolerance. Clinical presentations included chronic abdominal pain, chronic diarrhea, chronic constipation, emesis, and nausea. Statistical significance was reached for chronic constipation, emesis, and nausea, being less likely to be found in FBHT-positive patients. Thus, fructose intolerance may help resolve symptoms in patients with chronic functional constipation.

Perspective: The Paradox in Dietary Advanced Glycation End Products Research-The Source of the Serum and Urinary Advanced Glycation End Products Is the Intestines, Not the Food

Inconsistent research results have impeded our understanding of the degree to which dietary advanced glycation end products (dAGEs) contribute to chronic disease. Early research suggested that Western-style fast foods, including grilled and broiled meats and French fries, contain high levels of proinflammatory advanced glycation end products (AGEs). However, recent studies with state-of-the-art ultraperformance LC-tandem mass spectrometry (UPLC-MS) found that there is no evidence that these foods have elevated levels of dAGEs relative to other foods. Paradoxically, observational research found that the intake of fruits (mainly apples), fruit juices (apple juice), vegetables, nuts, seeds, soy, and nonfat milk, which are foods synonymous with healthy eating, as well as the intake of cold breakfast cereals, whole grains (breads), and sweets, which are sources of high-fructose corn syrup (HFCS), were associated with elevated serum and urinary N-ε-carboxymethyl-lysine (CML). Ironically, these are the same foods found to have lower CML levels, as measured by UPLC-MS. One possible explanation for this paradox is that the source of the elevated CML is the intestines, not the food. When considered collectively, dAGE research results are consistent with the "fructositis" hypothesis, which states that intake of foods and beverages with high fructose-to-glucose ratios (HFCS-sweetened foods and beverages, agave syrup, crystalline fructose, apple juice, and apple juice blends) promotes the intestinal in situ formation of readily absorbed, proinflammatory extracellular, newly identified, fructose-associated AGE, an overlooked source of immunogenic AGEs.

Intake of high fructose corn syrup sweetened soft drinks, fruit drinks and apple juice is associated with prevalent coronary heart disease, in U.S. adults, ages 45-59 y

BACKGROUND

Intake of high excess free fructose (EFF) beverages, including high fructose corn syrup (HFCS), sweetened soft drinks, fruit drinks, and apple juice, may be associated with childhood asthma, adult idiopathic chronic bronchitis/ COPD, and autoimmune arthritis, possibly due to underlying fructose malabsorption. Fructose malabsorption may contribute to the intestinal in situ formation of advanced glycation end-products (enFruAGEs) that travel to other tissues and promote inflammation. Chronic respiratory conditions and arthritis are comorbidities of coronary heart disease (CHD). The objective of this study was to investigate the association between intake of high EFF beverages and CHD.

METHODS

In this cross sectional study (NHANES 2003-2006) of adults, aged 45-59 y, n = 1230, the exposure variables were non-diet soft drinks, and any combination of high EFF beverages including non-diet soft drinks, fruit drinks, and apple juice. Analyses of diet soft drinks, diet fruit drinks, and orange juice (non/low EFF beverages) were included for comparison. The outcome was self-reported history of coronary heart disease and/or angina (CHD). Rao Scott Ҳ2 was used for prevalence differences and logistic regression for associations, adjusted for age, sex, race-ethnicity, BMI, socio-economic status, health insurance coverage, smoking, physical activity level, hypertension, energy intake, fruit and vegetable intake, glycated hemoglobin, pre-diabetes, and diabetes.

RESULTS

Intake of any combination of HFCS sweetened soft drinks, fruit drinks, and apple juice (tEFF) was significantly associated with CHD in adults aged 45-59 y. Adults consuming tEFF ≥5 times/wk. were 2.8 times more likely to report CHD than ≤3 times/mo consumers (OR 2.82; 95% CI 1.16-6.84; P = 0.023), independent of all covariates.

CONCLUSION

HFCS sweetened soft drinks, fruit drinks, and apple juice may contribute to CHD, a common comorbidity of chronic respiratory conditions and autoimmune arthritis, possibly due to the high ratio of fructose to glucose in these beverages. Underlying fructose malabsorption may contribute to the intestinal in situ formation of pro-inflammatory enFruAGEs, that are eventually absorbed and induce inflammation of the coronary arteries. Additional research is needed.

Lactose and Fructose Intolerance in Turkish Children with Chronic Abdominal Pain

OBJECTIVE

To investigate the prevalence of lactose and fructose intolerance in children with chronic abdominal pain.

METHODS

Hydrogen breath tests were done to detect lactose and fructose malabsorption in 86 children with chronic abdominal pain (44 irritable bowel syndrome, 24 functional abdominal pain and 17 functional abdominal pain syndrome as per Rome III criteria) presenting to a Pediatric Gastroentreology department.

RESULTS

14 (16.3%) of patients were diagnosed with lactose intolerance and 11 (12.8%) with fructose intolerance.

CONCLUSION

Lactose and fructose intolerance in children can lead to chronic abdominal pain and symptoms improve with dietary modifications.

Adolescents with irritable bowel syndrome report increased eating-associated symptoms, changes in dietary composition, and altered eating behaviors: a pilot comparison study to healthy adolescents

BACKGROUND

About half of adult irritable bowel syndrome (IBS) patients report symptoms with eating and disordered eating habits. However, little is known about eating in adolescent IBS patients, a common age at which eating disorders develop. The aim of the study was to investigate if adolescents with IBS are more likely than healthy controls (HCs) to experience eating-associated symptoms (EAS), report disordered eating patterns, and show differences in diet composition.

METHODS

A total of 99 adolescents between 15 and 21 years-of-age participated (n = 48 IBS; n = 51 HCs). All subjects completed three 24-h dietary recalls and questionnaires on EAS and disordered eating.

KEY RESULTS

IBS patients were more likely to report EASs than HC (91.7% vs 28%, p < 0.001). Eating-associated symptoms were controlled by avoiding the offending food (97.7%), not eating any food even when hungry (43.2%), or vomiting after eating (13.6%). Compared to HC, IBS patients reported reduced daily intake of overall calories (1828 vs 2139; p < 0.05), fat (65.4 g vs 81.4 g, p < 0.05), and lactose (8.2 g vs 12.8 g, p < 0.01). No differences were found between IBS and HC in screening for disordered eating patterns or BMI, though IBS patients endorsed using potentially unhealthy eating behaviors in an attempt to control symptoms.

CONCLUSIONS & INFERENCES

Eating-associated symptoms are very common in adolescents with IBS and associated with changes in eating behaviors and dietary composition. They do not appear to change BMI and risk for eating disorders. More research is needed to guide adolescents with IBS in making appropriate dietary changes to control EASs.

Approach to a Child with Functional Abdominal Pain

Functional abdominal pain (FAP) is one of the most common functional gastrointestinal disorders (FGIDs) of childhood. Only a minority of patients with FAP seek medical attention, often presenting to the primary care physician while symptoms are still evolving. The bio-psychosocial model of treatment not only aims to alleviate the illness symptoms but also identifies and remedies the psychological comorbidities and social factors that contribute to illness behavior. Many patients with a mild illness can be managed in the primary care setting. However those with chronic, severe, frequently relapsing, and disabling illness usually are referred to a pediatric gastroenterologist. One of the reason for referral is to exclude organic disorders such as peptic ulcer disease, celiac disease or inflammatory bowel disease which can present with chronic abdominal pain. Recent data suggest that psychological therapy is very effective in alleviating symptoms, a subset of patients may require dietary modification and medications as an adjunct to psychological treatment.

Dietary Carbohydrates and Childhood Functional Abdominal Pain

Childhood functional gastrointestinal disorders (FGIDs) affect a large number of children throughout the world. Carbohydrates (which provide the majority of calories consumed in the Western diet) have been implicated both as culprits for the etiology of symptoms and as potential therapeutic agents (e.g., fiber) in childhood FGIDs. In this review, we detail how carbohydrate malabsorption may cause gastrointestinal symptoms (e.g., bloating) via the physiologic effects of both increased osmotic activity and increased gas production from bacterial fermentation. Several factors may play a role, including: (1) the amount of carbohydrate ingested; (2) whether ingestion is accompanied by a meal or other food; (3) the rate of gastric emptying (how quickly the meal enters the small intestine); (4) small intestinal transit time (the time it takes for a meal to enter the large intestine after first entering the small intestine); (5) whether the meal contains bacteria with enzymes capable of breaking down the carbohydrate; (6) colonic bacterial adaptation to one's diet, and (7) host factors such as the presence or absence of visceral hypersensitivity. By detailing controlled and uncontrolled trials, we describe how there is a general lack of strong evidence supporting restriction of individual carbohydrates (e.g., lactose, fructose) for childhood FGIDs. We review emerging evidence suggesting that a more comprehensive restriction of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) may be effective. Finally, we review how soluble fiber (a complex carbohydrate) supplementation via randomized controlled intervention trials in childhood functional gastrointestinal disorders has demonstrated efficacy.

Diagnosing and Treating Intolerance to Carbohydrates in Children

Intolerance to carbohydrates is relatively common in childhood, but still poorly recognized and managed. Over recent years it has come to the forefront because of progresses in our knowledge on the mechanisms and treatment of these conditions. Children with intolerance to carbohydrates often present with unexplained signs and symptoms. Here, we examine the most up-to-date research on these intolerances, discuss controversies relating to the diagnostic approach, including the role of molecular analysis, and provide new insights into modern management in the pediatric age, including the most recent evidence for correct dietary treatment.

Intake of high-fructose corn syrup sweetened soft drinks, fruit drinks and apple juice is associated with prevalent arthritis in US adults, aged 20-30 years

OBJECTIVE

There is a link between joint and gut inflammation of unknown etiology in arthritis. Existing research indicates that regular consumption of high-fructose corn syrup sweetened (HFCS) soft drinks, but not diet soft drinks, may be associated with increased risk of seropositive rheumatoid arthritis (RA) in women, independent of other dietary and lifestyle factors. One unexplored hypothesis for this association is that fructose malabsorption, due to regular consumption of excess free fructose (EFF) and HFCS, contributes to fructose reactivity in the gastrointestinal tract and intestinal in situ formation of enFruAGEs, which once absorbed, travel beyond the intestinal boundaries to other tissues and promote inflammation. In separate studies, the accumulation of advanced glycation end-products has been associated with joint inflammation in RA. Objective of this study was to assess the association between EFF beverages intake and non-age, non-wear and tear-associated arthritis in US young adults.

METHODS

In this cross sectional study of 1209 adults aged 20-30y, (Nutrition and Health Examination Surveys 2003-2006) exposure variables were high EFF beverages, including HFCS sweetened soft drinks, and any combination of HFCS sweetened soft drinks, fruit drinks (FD) and apple juice, referred to as tEFF. Analyses of diet soda and diet FD were included for comparison. The outcome was self-reported arthritis. Rao Scott Ҳ(2) was used for prevalence differences and logistic regression for associations, adjusted for confounders.

RESULTS

Young adults consuming any combination of high EFF beverages (tEFF) ⩾5 times/week (but not diet soda) were three times as likely to have arthritis as non/low consumers (odds ratios=3.01; p⩽0.021; 95% confidence intervals=1.20-7.59), independent of all covariates, including physical activity, other dietary factors, blood glucose and smoking.

CONCLUSION

EFF beverage intake is significantly associated with arthritis in US adults aged 20-30 years, possibly due to the intestinal in situ formation of enFruAGEs.

Intake of high fructose corn syrup sweetened soft drinks is associated with prevalent chronic bronchitis in U.S. Adults, ages 20-55 y

BACKGROUND

High fructose corn syrup (HFCS) sweetened soft drink intake has been linked with asthma in US high-schoolers. Intake of beverages with excess free fructose (EFF), including apple juice, and HFCS sweetened fruit drinks and soft drinks, has been associated with asthma in children. One hypothesis for this association is that underlying fructose malabsorption and fructose reactivity in the GI may contribute to in situ formation of enFruAGEs. EnFruAGEs may be an overlooked source of advanced glycation end-products (AGE) that contribute to lung disease. AGE/ RAGEs are elevated in COPD lungs. EFF intake has increased in recent decades, and intakes may exceed dosages associated with adult fructose malabsorption in subsets of the population. Intestinal dysfunction has been shown to be elevated in COPD patients. The objective of this study was to investigate the association between HFCS sweetened soft drink intake and chronic bronchitis (CB), a common manifestation of COPD, in adults.

METHODS

DESIGN

In this cross sectional analysis, the outcome variable was self-reported existing chronic bronchitis or history of CB. Exposure variable was non-diet soda. Rao Scott Ҳ(2) was used for prevalence differences and logistic regression for associations, adjusted for age, sex, race-ethnicity, BMI, smoking, exposure to in-home smoking, pre-diabetes, diabetes, SES, total energy and total fruits and beverages consumption.

SETTING

Data are from the National Health and Nutrition Examination Survey 2003-2006.

SUBJECTS

2801 adults aged 20-55 y.

RESULTS

There was a statistically significant correlation between intake of non-diet soft drinks and greater prevalence and odds of chronic bronchitis (p < 0.05). Independent of all covariates, intake of non-diet soda ≥5 times a week (vs. non/low non-diet soda) was associated with nearly twice the likelihood of having chronic bronchitis (OR = 1.80; p = 0.047; 95% CI 1.01-3.20).

CONCLUSIONS

HFCS sweetened soft drink intake is correlated with chronic bronchitis in US adults aged 20-55 y, after adjusting for covariates, including smoking. Results support the hypothesis that underlying fructose malabsorption and fructose reactivity in the GI may contribute to chronic bronchitis, perhaps through in situ formation of enFruAGEs, which may contribute to lung disease. Longitudinal and biochemical research is needed to confirm and clarify the mechanisms involved.

Effects of dietary education, followed by a tailored fructose-restricted diet in adults with fructose malabsorption

OBJECTIVE

Fructose is absorbed by GLUT transporters in the small intestine. If this process is inadequate, abdominal symptoms because of fructose intolerance may arise. The effect of a tailored fructose-restricted diet on gastrointestinal complaints was assessed in patients with fructose intolerance.

MATERIALS AND METHODS

Following an abnormal fructose breath test (50 g), 107 patients (64 also with lactose intolerance) entered three study periods: weeks 0-32 (free diet), weeks 32-36 (progressive increasing amount of fructose up to quantity inducing symptoms, 'trigger dose'), and weeks 36-48 (tailored fructose-restricted diet according to the 'trigger dose'). A subgroup of 15 patients underwent additional fructose breath tests (35, 25 g) to compare three different doses.

RESULTS

At baseline, the most frequent symptoms were bloating and abdominal pain, and were more severe with combined fructose and lactose intolerance. During the free diet, patients reported eliminating (48%) or reducing (52%) fructose-containing foods, with a significant improvement in symptoms (abdominal pain from 79.7 ± 1.3 to 19.3 ± 1.8 mm; bloating from 83.1 ± 1.3 to 19.4 ± 1.8 mm; number of evacuations/day from 3.9 ± 0.16 to 1.1 ± 0.04; Bristol score from 5.1 ± 0.14 to 3.8 ± 0.1, P < 0.00001). During the tailored fructose-restricted diet, the consistent improvement in symptoms persisted and was similar to the improvement on free diet (abdominal pain 23.6 ± 1.9 mm; bloating 19.4 ± 1.8 mm; number of evacuations/day 1.7 ± 0.07; Bristol score 3.5 ± 0.06, P<0.00001 vs. baseline). A dose-dependent effect of fructose was observed on symptoms during the fructose breath test.

CONCLUSION

In our setting, individuals with fructose intolerance show an inappropriate dietary self-management. By contrast, a tailored fructose-restricted diet improves gastrointestinal symptoms without senseless food deprivation.

Intakes of apple juice, fruit drinks and soda are associated with prevalent asthma in US children aged 2-9 years

OBJECTIVE

High soft drink consumption has been linked with asthma. Anecdotal evidence links high-fructose corn syrup with asthma. The receptor of advanced glycation end products (RAGE) has emerged as a mediator of asthma. The objectives of the present study were to: (i) assess the correlation between intake of beverages containing excess free fructose (EFF beverages) and asthma in children; and (ii) epidemiologically test the mechanistic hypothesis that intake of high EFF beverages, such as apple juice or beverages sweetened with high-fructose corn syrup, is associated with increased risk of asthma. This hypothesis is based on the possible effect of increases in the in situ intestinal formation of advanced glycation end products (enFruAGE) with EFF, which may be absorbed and play a role in RAGE-mediated asthma.

DESIGN

We examined cross-sectional associations between beverage intake and self-reported current or history of asthma. Exposure variables were EFF beverages, including apple juice (AJ), non-diet soft drinks (ndSD) and fruit drinks (FD). Orange juice (OJ), not an EFF beverage, was included as a comparison. Rao-Scott χ(2) analysis was used for prevalence differences and logistic regression for associations, adjusted for age, sex, race/ethnicity, BMI and total energy intake.

SETTING

Data are from the National Health and Nutrition Examination Survey 2003-2006, a nationally representative survey.

SUBJECTS

US children (n 1961) aged 2-9 years with complete responses on the dietary frequency questionnaire.

RESULTS

Intakes of EFF beverages were significantly associated with asthma in 2-9-year-olds. Adjusted odds of asthma in children consuming EFF beverages ≥5 times/week was more than five times that in children consuming these beverages ≤1 time/month (OR=5·29, P=0·012). Children consuming AJ ≥5 times/week v. ≤1 time/month, adjusted for the other beverages, were more than twice as likely to have asthma (OR=2·43, P=0·035). In contrast, there was a tendency for OJ to be protective.

CONCLUSIONS

These results support the hypothesis that intake of high EFF beverages, including AJ and beverages sweetened with high-fructose corn syrup, is associated with asthma in children aged 2-9 years. Results support the mechanistic hypothesis that enFruAGE may be an overlooked contributor to asthma in children. Longitudinal studies are needed to provide evidence of causal association.

Fructose malabsorption in children with functional digestive disorders

CONTEXT

Fructose is a monosaccharide frequently present in natural and artificial juice fruits. When the concentration of fructose in certain food is present in excess of glucose concentration some individuals may develop fructose malabsorption.

OBJECTIVES

To report the frequency of fructose malabsorption utilizing the hydrogen breath test in children with gastrointestinal and/or nutritional disorders.

METHODS

Between July 2011 and July 2012, 43 patients with gastrointestinal and/or nutritional disorders, from both sexes, were consecutively studied, utilizing the hydrogen breath test with loads of the following carbohydrates: lactose, glucose, fructose and lactulose. Fructose was offered in a 10% aqueous solution in the dose of 1 g/kg body weight. Samples were collected fasting and at every 15 minutes after the intake of the aqueous solution for a 2 hour period. Malabsorption was considered when there was an increase of >20 ppm of hydrogen over the fasting level, and intolerance was diagnosed if gastrointestinal symptoms would appear.

RESULTS

The age of the patients varied from 3 months to 16 years, 24 were boys. The following diagnosis were established: irritable bowel syndrome with diarrhea in 16, functional abdominal pain in 8, short stature in 10, lactose intolerance in 3, celiac disease in 1, food allergy in 1 and giardiasis in 1 patient. Fructose malabsorption was characterized in 13 (30.2%) patients, and intolerance in 1 (2.3%) patient. The most frequent fructose malabsorption was characterized in 7 (16.3%) patients with irritable bowel syndrome and in 4 (9.3%) patients with functional abdominal pain.

CONCLUSIONS

Patients with irritable bowel syndrome and functional abdominal pain were the main cause of fructose malabsorption.

Fructose intolerance/malabsorption and recurrent abdominal pain in children

OBJECTIVES

The purpose of the present study was to ascertain whether pediatric patients with chronic abdominal pain had concurrent fructose intolerance as determined by a standardized dose breath hydrogen test (BHT), and whether symptoms would improve with a low-fructose diet.

METHODS

The fructose BHT test was administered to patients evaluated in clinic with unexplained chronic abdominal pain alone or associated with constipation, gas or bloating, and/or diarrhea. The patients were given a standard dose of 1 g/kg fructose to maximum of 25 g. Hydrogen and methane were measured at 8 time points. The test was presumed positive if breath hydrogen exceeded 20 ppm above baseline. If positive, patients were given a dietitian-prescribed low-fructose diet.

RESULTS

A total of 222 patients were part of the study. Ages ranged from 2 to 19 years with a mean of 10.5. BHT for fructose was performed in all of the patients and it was positive for fructose intolerance in 121 of 222 patients (54.5%). A total of 101 of 222 (45.5%) patients had negative BHT for fructose intolerance. All BHT-positive patients had a nutrition consult with a registered dietitian and were placed on a low-fructose diet. Using a standard pain scale for children, 93 of 121 patients (76.9%) reported resolution of symptoms on a low-fructose diet (P < 0.0001). Furthermore, 55 of 101 patients (54.4%) with negative BHT for fructose reported resolution of symptoms without a low-fructose diet (P = 0.37).

CONCLUSIONS

Fructose intolerance/malabsorption is common in children with recurrent/functional abdominal pain and a low-fructose diet is an effective treatment.

Gut microbiota influences low fermentable substrate diet efficacy in children with irritable bowel syndrome

We sought to determine whether a low fermentable substrate diet (LFSD) decreases abdominal pain frequency in children with irritable bowel syndrome (IBS) and to identify potential microbial factors related to diet efficacy. Pain symptoms, stooling characteristics, breath hydrogen and methane, whole intestinal transit time, stool microbiome, and metabolite composition were collected and/or documented in eight children with IBS at baseline and during one week of an LFSD intervention. Pain frequency (P<0.05), pain severity (P<0.05), and pain-related interference with activities (P<0.05) decreased in the subjects while on the LFSD. Responders vs. non-responders: four children (50%) were identified as responders (> 50% decrease in abdominal pain frequency while on the LFSD). There were no differences between responders and non-responders with respect to hydrogen production, methane production, stooling characteristics, or gut transit time. Responders were characterized by increased pre-LFSD abundance of bacterial taxa belonging to the genera Sporobacter (P<0.05) and Subdoligranulum (P<0.02) and decreased abundance of taxa belonging to Bacteroides (P<0.05) relative to non-responders. In parallel, stool metabolites differed between responders and non-responders and were associated with differences in microbiome composition. These pilot study results suggest that an LFSD may be effective in decreasing GI symptoms in children with IBS. Microbial factors such as gut microbiome composition and stool metabolites while on the diet may relate to LFSD efficacy.

Significance of hydrogen breath tests in children with suspected carbohydrate malabsorption

BACKGROUND

Hydrogen breath tests are noninvasive procedures frequently applied in the diagnostic workup of functional gastrointestinal disorders. Here, we review hydrogen breath test results and the occurrence of lactose, fructose and sorbitol malabsorption in pediatric patients; and determine the significance of the findings and the outcome of patients with carbohydrate malabsorption.

METHODS

We included 206 children (88 male, 118 female, median age 10.7 years, range 3-18 years) with a total of 449 hydrogen breath tests (lactose, n = 161; fructose, n = 142; sorbitol, n = 146) into a retrospective analysis. Apart from test results, we documented symptoms, the therapeutic consequences of the test, the outcome and the overall satisfaction of the patients and families.

RESULTS

In total, 204 (46%) of all breath tests were positive. Long-term follow-up data could be collected from 118 patients. Of 79 patients (67%) who were put on a diet reduced in lactose, fructose and/or sorbitol, the majority (92%, n = 73) reported the diet to be strict and only 13% (n = 10) had no response to diet. Most families (96%, n = 113) were satisfied by the test and the therapy. There were only 21 tests (5%) with a borderline result because the criteria for a positive result were only partially met.

CONCLUSIONS

Hydrogen breath tests can be helpful in the evaluation of children with gastrointestinal symptoms including functional intestinal disorders. If applied for a variety of carbohydrates but only where indicated, around two-third of all children have positive results. The therapeutic consequences are successfully relieving symptoms in the vast majority of patients.

Diet and functional abdominal pain in children and adolescents

Functional abdominal pain (FAP) is a common complaint among children and adolescents. For many patients, symptoms exacerbate with eating. This review discusses findings concerning the role of diet in FAP. The foods that are discussed are divided into 2 major groups: food allergies or intolerances, which focus on milk, gluten, and fermentable oligosaccharides, disaccharides, monosaccharides, and polyols; and functional foods, which hone in on foods that reduce abdominal pain in adolescents such as fiber, peppermint oil, and probiotics. Lastly, we discuss the role of eating habits in FAP and how the physiology of eating may be the real culprit of symptoms associated with eating.

Functional abdominal pain in childhood: background studies and recent research trends

The present review summarizes many of the major research trends investigated in the past five years regarding pediatric functional abdominal pain, and also summarizes the primary related findings from the authors' research program. Specific areas discussed based on work within the authors' group include familial illness patterns, genetics, traits, and mechanisms or processes related to abdominal pain. Topics covered from research published in the past five years include prevalence and cost, longitudinal follow-up, overlap with other disorders, etiology and mechanisms behind functional abdominal pain and treatment studies. It is hoped that findings from this work in abdominal pain will be interpreted as a framework for understanding the processes by which other pain phenomena and, more broadly, reactions to any physical state, can be developed and maintained in children. The present article concludes with recommendations for clinical practice and research.

The role of fructose transporters in diseases linked to excessive fructose intake

Fructose intake has increased dramatically since humans were hunter-gatherers, probably outpacing the capacity of human evolution to make physiologically healthy adaptations. Epidemiological data indicate that this increasing trend continued until recently. Excessive intakes that chronically increase portal and peripheral blood fructose concentrations to >1 and 0.1 mm, respectively, are now associated with numerous diseases and syndromes. The role of the fructose transporters GLUT5 and GLUT2 in causing, contributing to or exacerbating these diseases is not well known. GLUT5 expression seems extremely low in neonatal intestines, and limited absorptive capacities for fructose may explain the high incidence of malabsorption in infants and cause problems in adults unable to upregulate GLUT5 levels to match fructose concentrations in the diet. GLUT5- and GLUT2-mediated fructose effects on intestinal electrolyte transporters, hepatic uric acid metabolism, as well as renal and cardiomyocyte function, may play a role in fructose-induced hypertension. Likewise, GLUT2 may contribute to the development of non-alcoholic fatty liver disease by facilitating the uptake of fructose. Finally, GLUT5 may play a role in the atypical growth of certain cancers and fat tissues. We also highlight research areas that should yield information needed to better understand the role of these GLUTs in fructose-induced diseases.

Fructose malabsorption and intolerance: effects of fructose with and without simultaneous glucose ingestion

Concern exists that increasing fructose consumption, particularly in the form of high-fructose corn syrup, is resulting in increasing rates of fructose intolerance and aggravation of clinical symptoms in individuals with irritable bowel syndrome. Most clinical trials designed to test this hypothesis have used pure fructose, a form not commonly found in the food supply, often in quantities and concentrations that exceed typical fructose intake levels. In addition, the amount of fructose provided in tests for malabsorption, which is thought to be a key cause of intolerance, often exceeds the normal physiological absorption capacity for this sugar. To help health professionals accurately identify and treat this condition, this article reviews clinical data related to understanding fructose malabsorption and intolerance (i.e., malabsorption that manifests with symptoms) relative to usual fructose and other carbohydrate intake. Because simultaneous consumption of glucose attenuates fructose malabsorption, information on the fructose and glucose content of foods, beverages, and ingredients representing a variety of food categories is provided.

Recurrent abdominal pain in 200 children: somatic causes and diagnostic criteria

AIM

To establish to what extent somatic causes can be found in children referred to secondary care with recurrent abdominal pain.

METHODS

For 2 years, all consecutive patients (age 4-16 years) fulfilling Apley criteria, referred to secondary care, were included. After a diagnostic work-up, stepwise therapeutic interventions were performed. A diagnosis was considered to be the cause of the pain when the patient became pain free following therapeutic intervention and remained so for at least 6 months.

RESULTS

Two hundred and twenty children (128 F, 92 M; mean age 8.8 years) were enrolled, of which 20 were lost to follow-up. Spontaneous recovery was seen in 54 patients, (occult) constipation in 92 patients (of whom 18 also had a somatic cause), gastrointestinal infections in 40, food allergy in five, miscellaneous disorders in seven and uncertain diagnosis in 13. In five patients, stress most likely caused the pain. A total of 198 patients became pain free and remained so during follow-up (mean 18, range 6-60 months).

CONCLUSION

In 200 children with recurrent abdominal pain, somatic causes were found in 26%. Laxative therapy was successful in 46%, resulting in nearly all patients with functional abdominal pain to become pain free. Eventually, 99% became pain free using a therapeutic intervention protocol.

Functional abdominal pain and irritable bowel syndrome in children and adolescents

Functional abdominal pain (FAP) and irritable bowel syndrome (IBS) are both associated with recurrent abdominal pain and are among the most commonly diagnosed medical problems in pediatrics. The majority of patients with mild complaints improve with reassurance and time. For a distinct subset of patients with more severe and disabling illness, finding effective treatment for these disorders remains a challenge. Based on the biopsychosocial model of functional disease, the Rome III criteria have helped frame FAP and IBS in terms of being a positive diagnosis and not a diagnosis of exclusion. However, the lack of a single, proven intervention highlights the complex interplay of pathologic mechanisms likely involved in the development of childhood FAP and IBS and the need for a multidisciplinary, integrated approach. This article discusses the epidemiology, proposed mechanisms, clinical approach and therapeutic options for the management of FAP and IBS in children and adolescents.

Effect of age on fructose malabsorption in children presenting with gastrointestinal symptoms

OBJECTIVES

Fructose malabsorption can produce symptoms such as chronic diarrhoea and abdominal pain. Here, we retrospectively review breath hydrogen test (BHT) results to determine whether age has an effect on the clinical application of the fructose BHT and compare this with the lactose BHT.

PATIENTS AND METHODS

Patients were referred to a gastroenterology breath-testing clinic (2003-2008) to investigate carbohydrate malabsorption as a cause of gastrointestinal symptoms. Patients received either 0.5 g/kg body weight of fructose (maximum of 10 g) or 2 g/kg of lactose (maximum of 20 g), in water, and were tested for 2.5 hours.

RESULTS

Patient age showed a significant effect on the fructose BHT results (P < 0.001, 0.1-79 years old, n = 1093). The odds of testing positive for fructose malabsorption in paediatric patients (15 years old or younger, n = 760) decreased by a factor of 0.82/year (95% confidence interval 0.79-0.86, P < 0.001). There were 88.2% positive in younger than 1-year-olds, 66.6% in 1- to 5-year-olds, 40.4% in 6- to 10-year-olds, and 27.1% in 10- to 15-year-olds. In contrast, 39.3% of lactose BHTs were positive, with no significant relation between patient age and test result (P = 0.115, 0.1-89 years old, n = 3073).

CONCLUSIONS

The majority of infants with gastrointestinal symptoms exhibited fructose malabsorption, but the capacity to absorb fructose increased with patient age up to 10 years old. The low threshold for fructose absorption in younger children has significant implications for the performance and interpretation of the fructose BHT and for the dietary consumption of fructose in infants with gastrointestinal symptoms.

Triple sugar screen breath hydrogen test for sugar intolerance in children with functional abdominal symptoms

BACKGROUND

Sugar intolerance and functional gastrointestinal disorders are both common in school age children. Both may present with similar complaints such as abdominal pain, diarrhea and bloating. Lactose, fructose and sucrose hydrogen breath tests are widely used to detect sugar malabsorption.

AIM

To determine the proportion of children with symptoms of functional gastrointestinal disorders (FGID) that have sugar intolerance as determined by using a breath hydrogen test.

METHODS

We prospectively enrolled subjects with chronic abdominal pain, bloating and/or chronic diarrhea. All subjects underwent triple sugar screen hydrogen breath test (TSST) using the combined sugar solution. Breath hydrogen concentration ≥ 20 ppm above baseline was interpreted a positive test for sugar malabsorption.

RESULTS

A positive hydrogen breath test consistent with sugar malabsorption was found in 5 out of 31 (16%) subjects. Three of these subjects were confirmed to have lactose malabsorption based on small bowel lactase enzyme analysis or subsequent lactose hydrogen breath test. One subject with positive TSST was diagnosed with fructose malabsorption based on dietary history; he improved on a limited fructose diet, and one was diagnosed to have gastric Crohn's disease.

CONCLUSION

Approximately one in six children with symptoms of FGID had sugar intolerance as determined by the TSST.

Management of functional abdominal pain and irritable bowel syndrome in children and adolescents

Functional abdominal pain (FAP) and irritable bowel syndrome (IBS) are among the most commonly diagnosed medical problems in pediatrics. Symptom-based Rome III criteria for FAP and IBS have been validated and help the clinician in making a positive diagnosis. The majority of patients with mild complaints improve with reassurance and time. For a distinct subset of patients with more severe and disabling illness, finding effective treatment for these disorders remains a challenge. Over the years, a wide range of therapies have been proposed and studied. The lack of a single, proven intervention highlights the complex interplay of biopsychosocial factors probably involved in the development of childhood FAP and IBS, and the need for a multidisciplinary, integrated approach. This article reviews the current literature on the efficacy of pharmacologic, dietary and psychosocial interventions for FAP and IBS in children and adolescents.