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

Disproportionately higher cardiovascular disease risk and incidence with high fructose corn syrup sweetened beverage intake among black young adults-the CARDIA study

BACKGROUND

The black/white heart disease mortality disparity began increasing in the early 1980's, coincident with the switch from sucrose to high-fructose-corn-syrup/(HFCS) in the US food supply. There has been more fructose in HFCS than generally-recognized-as-safe/GRAS, which has contributed to unprecedented excess-free-fructose/(unpaired-fructose) in foods/beverages. Average- per-capita excess-free-fructose, from HFCS, began exceeding dosages/(5-10 g) that trigger fructose-malabsorption in the early 1980's. Fructose malabsorption contributes to gut-dysbiosis and gut-in-situ-fructosylation of dietary peptides/incretins/(GLP-1/GIP) which forms atherosclerotic advanced-glycation-end-products. Both dysregulate gut endocrine function and are risk factors for cardiovascular disease/(CVD). Limited research shows that African Americans have higher fructose malabsorption prevalence than others. CVD risk begins early in life.

METHODS

Coronary-Artery-Risk-Development-in-Adults/(CARDIA) study data beginning in 1985-86 with 2186 Black and 2277 White participants, aged 18-30 y, were used to test the hypothesis that HFCS sweetened beverage intake increases CVD risk/incidence, more among Black than White young adults, and at lower intakes; while orange juice-a low excess-free-fructose juice with comparable total sugars and total fructose, but a 1:1 fructose-to-glucose-ratio, i.e., low excess-free-fructose, does not. Cox proportional hazards models were used to calculate hazard ratios.

RESULTS

HFCS sweetened beverage intake was associated with higher CVD risk (HR = 1.7) than smoking (HR = 1.6). CVD risk was higher at lower HFCS sweetened beverage intake among Black than White participants. Intake, as low as 3 times/wk, was associated with twice the CVD risk vs. less frequent/never, among Black participants only (HR 2.1, 95% CI 1.2-3.7; P = 0.013). Probability of an ordered relationship approached significance. Among Black participants, CVD incidence jumped 62% from 59.8/1000, among ≤ 2-times/wk, to 96.9/1000 among 3-6 times/wk consumers. Among White participants, CVD incidence increased from 37.6/1000, among ≤ 1.5-times/wk, to 41.1/1000, among 2 times/wk-once/d - a 9% increase. Hypertension was highest among Black daily HFCS sweetened beverage consumers.

CONCLUSION

The ubiquitous presence of HFCS over-the-past-40 years, at higher fructose-to-glucose ratios than generally-recognized-as-safe, may have contributed to CVD racial disparities, due to higher fructose-malabsorption prevalence among Black individuals, unpaired/excess-free-fructose induced gut dysbiosis and gut fructosylation of dietary peptides/incretins (GLP-1/GIP). These disturbances contribute to atherosclerotic plaque; promote incretin insufficiency/dysregulation/altered satiety/dysglycemia; decrease protective microbiota metabolites; and increase hypertension, CVD morbidity and mortality.

40 years of adding more fructose to high fructose corn syrup than is safe, through the lens of malabsorption and altered gut health-gateways to chronic disease

Labels do not disclose the excess-free-fructose/unpaired-fructose content in foods/beverages. Objective was to estimate excess-free-fructose intake using USDA loss-adjusted-food-availability (LAFA) data (1970-2019) for high fructose corn syrup (HFCS) and apple juice, major sources of excess-free-fructose, for comparison with malabsorption dosages (~ 5 g-children/ ~ 10 g-adults). Unlike sucrose and equimolar fructose/glucose, unpaired-fructose triggers fructose malabsorption and its health consequences. Daily intakes were calculated for HFCS that is generally-recognized-as-safe/ (55% fructose/45% glucose), and variants (65/35, 60/40) with higher fructose-to-glucose ratios (1.9:1, 1.5:1), as measured by independent laboratories. Estimations include consumer-level-loss (CLL) allowances used before (20%), and after, subjective, retroactively-applied increases (34%), as recommended by corn-refiners (~ 2012). No contributions from crystalline-fructose or agave syrup were included due to lack of LAFA data. High-excess-free-fructose-fruits (apples/pears/watermelons/mangoes) were not included. Eaten in moderation they are less likely to trigger malabsorption. Another objective was to identify potential parallel trends between excess-free-fructose intake and the "unexplained" US asthma epidemic. The fructose/gut-dysbiosis/lung axis is well documented, case-study evidence and epidemiological research link HFCS/apple juice intake with asthma, and unlike gut-dysbiosis/gut-fructosylation, childhood asthma prevalence data spans > 40 years. Results Excess-free-fructose daily intake for individuals consuming HFCS with an average 1.5:1 fructose-to-glucose ratio, ranged from 0.10 g/d in 1970, to 11.3 g/d in 1999, to 6.5 g/d in 2019, and for those consuming HFCS with an average 1.9:1 ratio, intakes ranged from 0.13 g/d to 16.9 g/d (1999), to 9.7 g/d in 2019, based upon estimates with a 20% CLL allowance. Intake exceeded dosages that trigger malabsorption (~ 5 g) around ~ 1980. By the early 1980's, tripled apple juice intake had added ~ 0.5 g to average-per-capita excess-free-fructose intake. Contributions were higher (~ 3.8 g /4-oz.) for individuals consuming apple juice consistent with a healthy eating pattern (4-oz. children, 8-oz. adults). The "unexplained" childhood asthma epidemic (1980-present) parallels increasing average-per-capita HFCS/apple juice intake trends and reflects epidemiological research findings. Conclusion Displacement of sucrose with HFCS, its ubiquitous presence in the US food-supply, the industry practice of adding more fructose to HFCS than generally-recognized-as-safe, and increased use of apple juice/crystalline fructose/agave syrup in foods/beverages has contributed to unprecedented excess-free-fructose intake levels, fructose malabsorption, gut-dysbiosis and gut-fructosylation (immunogen burden)-gateways to chronic disease.

Adverse Food Reactions in Inflammatory Bowel Disease: State of the Art and Future Perspectives

Limited knowledge is available about the relationship between food allergies or intolerances and inflammatory bowel disease (IBD). Clinicians frequently encounter patients who report food allergies or intolerances, and gastroenterologists struggle distinguishing between patients with organic disorders and those with functional disorders, which the patients themselves may associate with specific dietary components. This task becomes even more arduous when managing patients with significant underlying organic conditions, like IBD. The aim of this review is to summarize and emphasize any actual associations between food allergies and intolerances and inflammatory diseases, such as ulcerative colitis and Crohn's disease. Through a narrative disceptation of the current literature, we highlight the increased prevalence of various food intolerances, including lactose, fructose, histamine, nickel, and non-celiac gluten sensitivity, in individuals with IBD. Additionally, we explore the association between increased epithelial barrier permeability in IBD and the development of food sensitization. By doing so, we aim to enhance clinicians' awareness of the nutritional management of patients with IBD when facing complaints or evidence of food allergies or intolerances.

Congenital disorders of intestinal digestion and absorption (sugars, proteins, lipids, ions)

Congenital diarrhea may result from 2 main different mechanisms: 1) osmotic diarrhea is caused by the non-digestion-absorption of nutrients leading to the non-absorbed nutrients going into the lumen, increasing the osmotic force and driving fluids; 2) secretory diarrhea induced by the inhibition of intestinal absorption of electrolytes, increasing electrolyte and water flux towards the intestinal lumen. The malabsorption of macronutrients (carbohydrates, proteins and lipids) induces energy deficiency with symptoms depending on the macronutrient: carbohydrates with watery acidic diarrhea; protein with rapid malnutrition, edema, and hypoalbuminemia; and lipids with malnutrition, steatorrhea and hypocholesterolemia. Ionic malabsorption (Cl and Na) is responsible for severe and rapid dehydration sometimes with prenatal abnormalities (polyhydramnios and bowel dilatation).

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.

Expression of the fructose transporter GLUT5 in patients with fructose malabsorption

BACKGROUND

 Patients with abdominal symptoms are frequently diagnosed with fructose malabsorption (FM). Fructose is absorbed by monosaccharide transporters located in the brush border of the human small intestine. The aim of this study was to investigate the histoanatomical distribution of the main fructose transporter GLUT5.

MATERIALS AND METHODS

 We studied 223 patients diagnosed with FM by a hydrogen breath test and grouped according to their response to a fructose-free diet. The control group were 42 healthy individuals and 29 patients with celiac disease (CD). The fructose breath test was done with 50 g fructose. The expression of Glut5 in duodenal biopsy specimens was studied by immunohistochemistry. The Kruskal-Wallis-test and Mann-Whitney U-test were used to carry out the statistical analysis.

RESULTS

 The histoanatomical expression pattern of GLUT5 did not differ significantly between those patients with FM who responded completely to a fructose-free diet (n = 183) and healthy individuals (n = 42); nor did it correlate to H2 production measured in fructose breath testing. In patients with FM, the GLUT5 expression pattern did not differ between those individuals responding to a fructose-free diet and those who did not. However, GLUT5 expression pattern was significantly different in patients with CD (n = 29) compared to patients with FM and to healthy individuals (p = 0.009).

CONCLUSION

 GLUT5 expression patterns are not be related to adult patients with FM. However, in secondary malabsorption, a decreased GLUT5 expression was found. Further investigation is needed to understand the essential factors in FM and the influence on functional gastrointestinal disorders.

Fructose malabsorption: causes, diagnosis and treatment

This review intends to act as an overview of fructose malabsorption (FM) and its role in the aetiology of diseases including, but not limited to, irritable bowel syndrome (IBS) and infantile colic and the relationship between fructose absorption and the propagation of some cancers. IBS results in a variety of symptoms including stomach pains, cramps and bloating. Patients can be categorised into two groups, depending on whether the patients’ experiences either constipation (IBS-C) or diarrhoea (IBS-D). FM has been proposed as a potential cause of IBS-D and other diseases, such as infantile colic. However, our knowledge of FM is limited by our understanding of the biochemistry related to the absorption of fructose in the small intestine and FM’s relationship with small intestinal bacterial overgrowth. It is important to consider the dietary effects on FM and most importantly, the quantity of excess free fructose consumed. The diagnosis of FM is difficult and often requires indirect means that may result in false positives. Current treatments of FM include dietary intervention, such as low fermentable oligo-, di-, monosaccharides and polyols diets and enzymatic treatments, such as the use of xylose isomerase. More research is needed to accurately diagnose and effectively treat FM. This review is designed with the goal of providing a detailed outline of the issues regarding the causes, diagnosis and treatment of FM.

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

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

High fructose corn syrup, excess-free-fructose, and risk of coronary heart disease among African Americans- the Jackson Heart Study

BACKGROUND

Researchers have sought to explain the black-white coronary heart disease (CHD) mortality disparity that increased from near parity to ~ 30% between 1980 and 2010. Contributing factors include cardiovascular disease prevention and treatment disparities attributable to disparities in insurance coverage. Recent research suggests that dietary/environmental factors may be contributors to the disparity. Unabsorbed/luminal fructose alters gut bacterial load, composition and diversity. There is evidence that such microbiome disruptions promote hypertension and atherosclerosis. The heart-gut axis may, in part, explain the black-white CHD disparity, as fructose malabsorption prevalence is higher among African Americans. Between 1980 and 2010, consumption of excess-free-fructose-the fructose type that triggers malabsorption-exceeded dosages associated with fructose malabsorption (~ 5 g-10 g), as extrapolated from food availability data before subjective, retroactively-applied loss adjustments. This occurred due to an industrial preference shift from sucrose to high-fructose-corn-syrup (HFCS) that began ~ 1980. During this period, HFCS became the main sweetener in US soda. Importantly, there has been more fructose in HFCS than thought, as the fructose-to-glucose ratio in popular sodas (1.9-to-1 and 1.5-to-1) has exceeded generally-recognized-as-safe levels (1.2-to-1). Most natural foods contain a ~ 1-to-1 ratio. In one recent study, ≥5 times/wk. consumers of HFCS sweetened soda/fruit drinks/and apple juice-high excess-free-fructose beverages-were more likely to have CHD, than seldom/never consumers.

METHODS

Jackson-Heart-Study data of African Americans was used to test the hypothesis that regular relative to low/infrequent intake of HFCS sweetened soda/fruit drinks increases CHD risk, but not orange juice-a low excess-free-fructose juice. Cox proportional hazards models were used to calculate hazard ratios using prospective data of 3407-3621 participants, aged 21-93 y (mean 55 y).

RESULTS

African Americans who consumed HFCS sweetend soda 5-6x/wk. or any combination of HFCS sweetened soda and/or fruit drinks ≥3 times/day had ~ 2 (HR 2.08, 95% CI 1.03-4.20, P = 0.041) and 2.5-3 times higher CHD risk (HR 2.98, 95% CI 1.15-7.76; P = 0.025), respectively, than never/seldom consumers, independent of confounders. There were no associations with diet-soda or 100% orange-juice, which has a similar glycemic profile as HFCS sweetened soda, but contains a ~ 1:1 fructose-to-glucose ratio.

CONCLUSION

The ubiquitous presence of HFCS in the food supply may pre-dispose African Americans to increased CHD risk.

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.

Paediatric constipation for general paediatricians: Review using a case-based and evidence-based approach

Constipation is a common problem in childhood. The most common type of constipation is functional, accounting for 90-95% of all cases. The aim of this review is to provide clinical scenarios with treatment using evidence-based information, and management strategies and a clinical algorithm to guide the management of constipation in children. Recent guidelines and online information sites are detailed. Clinical red flags and organic causes of constipation are included. Four clinical scenarios are presented: case (1) 4-month-old child with constipation since birth and likely Hirschsprung disease; case (2) 6-month-old infant with infant dyschezia; case (3) 4-year old with functional constipation; and; case (4) 9-year old with treatment resistant constipation. Children with functional constipation need a thorough history and physical exam to rule out the presence of any 'red flags' but do not require laboratory investigations. Management includes education and demystification, disimpaction followed by maintenance therapy with oral laxatives, dietary counselling and toilet training. Treatment options differ between infants and children. Disimpaction and maintenance regimens for common laxatives are presented. On treatment failure or on suspicion of organic disease the patient should be referred for further evaluation. The radionuclide intestinal transit study (scintigraphy) is a useful modality for evaluation and planning of management in treatment-resistant children. Treatment options for treatment-resistant patients are presented. High-level evidence (meta-analyses) for pharmalogical and non-pharmalogical treatment modalities are reviewed and an algorithm for assessment and treatment are presented.

Excess free fructose, apple juice, high fructose corn syrup and childhood asthma risk - the National Children's Study

BACKGROUND

Recent research provides consistent evidence that the unexplained doubling of childhood asthma prevalence (1980-1995), its continued climb and 2013 plateau, may be associated with the proliferation of high-fructose-corn-syrup (HFCS) in the US food supply. The HFCS used in soft drinks has been shown to contain a higher fructose-to-glucose ratio than previously thought. This coincides with a preference shift from orange to apple juice among young children. Apple juice naturally contains a high (≥2:1) fructose-to-glucose ratio. Thus, children have received high excess-free-fructose doses, the fructose type associated with fructose malabsorption. Unabsorbed excess-free-fructose in the gut may react with dietary proteins to form immunogens that bind asthma mediating receptors, and/or alter the microbiota towards a profile linked to lung disorders. Studies with longitudinal childhood data are lacking. Therefore, we tested the hypothesis that excess-free-fructose intake is associated with childhood asthma risk.

METHODS

Cox regression models were used to analyze prospective early childhood data (12-30 months of age) from the National Children's Study. Intake frequencies for soda/sports/fruit drinks, and 100% juices were used for analyses.

RESULTS

Greater consumption of 100% juice, soda/sports/fruit drinks, and any combination, was associated with ~two (P = 0.001), ~ 2.5 (P = 0.001), and ~ 3.5 times (P < 0.0001) higher asthma incidence.

CONCLUSIONS

Given these results, prior research and case-study evidence, it is reasonable to suggest that the two-fold higher asthma risk associated with 100% juice consumption is due to apple juice's high fructose-to-glucose ratio, and that the ~ 2.5/~ 3.5 times higher risk associated with soda/sports/fruit drinks intake is with the excess-free-fructose in HFCS.

'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.

Heterozygotes Are a Potential New Entity among Homozygotes and Compound Heterozygotes in Congenital Sucrase-Isomaltase Deficiency

Congenital sucrase-isomaltase deficiency (CSID) is an autosomal recessive disorder of carbohydrate maldigestion and malabsorption caused by mutations in the sucrase-isomaltase (SI) gene. SI, together with maltase-glucoamylase (MGAM), belongs to the enzyme family of disaccharidases required for breakdown of α-glycosidic linkages in the small intestine. The effects of homozygote and compound heterozygote inheritance trait of SI mutations in CSID patients have been well described in former studies. Here we propose the inclusion of heterozygote mutation carriers as a new entity in CSID, possibly presenting with milder symptoms. The hypothesis is supported by recent observations of heterozygote mutation carriers among patients suffering from CSID or patients diagnosed with functional gastrointestinal disorders. Recent studies implicate significant phenotypic heterogeneity depending on the character of the mutation and call for more research regarding the correlation of genetics, function at the cellular and molecular level and clinical presentation. The increased importance of SI gene variants in irritable bowel syndrome (IBS) or other functional gastrointestinal disorders FGIDs and their available symptom relief diets like fermentable oligo-, di-, mono-saccharides and polyols FODMAPs suggest that the heterozygote mutants may affect the disease development and treatment.

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.

Fructose malabsorption induces cholecystokinin expression in the ileum and cecum by changing microbiota composition and metabolism

Current fructose consumption levels often overwhelm the intestinal capacity to absorb fructose. We investigated the impact of fructose malabsorption on intestinal endocrine function and addressed the role of the microbiota in this process. To answer this question, a mouse model of moderate fructose malabsorption [ketohexokinase mutant (KHK)^-/-] and wild-type (WT) littermate mice were used and received a 20%-fructose (KHK-F and WT-F) or 20%-glucose diet. Cholecystokinin (Cck) mRNA and protein expression in the ileum and cecum, as well as preproglucagon (Gcg) and neurotensin (Nts) mRNA expression in the cecum, increased in KHK-F mice. In KHK-F mice, triple-label immunohistochemistry showed major up-regulation of CCK in enteroendocrine cells (EECs) that were glucagon-like peptide-1 (GLP-1)⁺/Peptide YY (PYY^-) in the ileum and colon and GLP-1^-/PYY^- in the cecum. The cecal microbiota composition was drastically modified in the KHK-F in association with an increase in glucose, propionate, succinate, and lactate concentrations. Antibiotic treatment abolished fructose malabsorption-dependent induction of cecal Cck mRNA expression and, in mouse GLUTag and human NCI-H716 cells, Cck mRNA expression levels increased in response to propionate, both suggesting a microbiota-dependent process. Fructose reaching the lower intestine can modify the composition and metabolism of the microbiota, thereby stimulating the production of CCK from the EECs possibly in response to propionate.-Zhang, X., Grosfeld, A., Williams, E., Vasiliauskas, D., Barretto, S., Smith, L., Mariadassou, M., Philippe, C., Devime, F., Melchior, C., Gourcerol, G., Dourmap, N., Lapaque, N., Larraufie, P., Blottière, H. M., Herberden, C., Gerard, P., Rehfeld, J. F., Ferraris, R. P., Fritton, J. C., Ellero-Simatos, S., Douard, V. Fructose malabsorption induces cholecystokinin expression in the ileum and cecum by changing microbiota composition and metabolism.

Erythritol Functional Roles in Oral-Systemic Health

Erythritol belongs chemically to the family of polyols (or sugar alcohols), yet it is metabolized by animals and humans very differently compared to all other polyols. While polyols have been used traditionally (for about 80 y) to replace sugar in sweet foods to reduce demineralization of tooth enamel and to reduce postprandial blood glucose levels, benefits achieved merely through the absence of sugar, emerging evidence shows that erythritol can play a number of functional roles to actively support maintenance of oral and systemic health. Oral health studies revealed that erythritol can reduce dental plaque weight, reduce dental plaque acids, reduce counts of mutans streptococci in saliva and dental plaque, and reduce the risk for dental caries better than sorbitol and xylitol, resulting in fewer tooth restorations by dentist intervention. Systemic health studies have shown that erythritol, unlike other polyols, is readily absorbed from the small intestine, not systemically metabolized, and excreted unchanged within the urine. This metabolic profile renders erythritol to be noncaloric, to have a high gastrointestinal tolerance, and not to increase blood glucose or insulin levels. Published evidence also shows that erythritol can act as an antioxidant and that it may improve endothelial function in people with type 2 diabetes. This article reviews the key research demonstrating erythritol's oral and systemic health functionalities and underlying mechanisms.

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.

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.

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-containing caloric sweeteners as a cause of obesity and metabolic disorders

Compared with other carbohydrates, fructose-containing caloric sweeteners (sucrose, high-fructose corn syrup, pure fructose and fructose-glucose mixtures) are characterized by: a sweet taste generally associated with a positive hedonic tone; specific intestinal fructose transporters, i.e. GLUT5; a two-step fructose metabolism, consisting of the conversion of fructose carbones into ubiquitous energy substrates in splanchnic organs where fructolytic enzymes are expressed, and secondary delivery of these substrates to extrasplanchnic tissues. Fructose is a dispensable nutrient, yet its energy can be stored very efficiently owing to a rapid induction of intestinal fructose transporters and of splanchnic fructolytic and lipogenic enzymes by dietary fructose-containing caloric sweeteners. In addition, compared with fat or other dietary carbohydrates, fructose may be favored as an energy store because it uses different intestinal absorption mechanisms and different inter-organ trafficking pathways. These specific features make fructose an advantageous energy substrate in wild animals, mainly when consumed before periods of scarcity or high energy turnover such as migrations. These properties of fructose storage are also advantageous to humans who are involved in strenuous sport activities. In subjects with low physical activity, however, these same features of fructose metabolism may have the harmful effect of favoring energy overconsumption. Furthermore, a continuous exposure to high fructose intake associated with a low energy turnover leads to a chronic overproduction of intrahepatic trioses-phosphate production, which is secondarily responsible for the development of hepatic insulin resistance, intrahepatic fat accumulation, and increased blood triglyceride concentrations. In the long term, these effects may contribute to the development of metabolic and cardiovascular diseases.

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.

The link between soda intake and asthma: science points to the high-fructose corn syrup, not the preservatives: a commentary

Recent research conducted by investigators at the National Center for Chronic Disease Prevention and Health Promotion—a division of the US Centers for Disease Control and Prevention (CDC)—found that 'Regular-Soda Intake, Independent of Weight Status, is Associated with Asthma among US High School Students.' On the basis of their review of prior studies, researchers hypothesized that the association may be due to high intake of sodium benzoate, a commonly used preservative in US soft drinks. But a closer look at these prior research studies suggests that there is no strong scientific evidence that the preservatives in US soft drinks are associated with asthma. Importantly, other recent research suggests that the association may be with the unpaired (excess free) fructose in high fructose corn syrup.

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.

Fructose malabsorption

Incomplete intestinal absorption of fructose might lead to abdominal complaints such as pain, flatulence and diarrhoea. Whether defect fructose transporters such as GLUT5 or GLUT2 are involved in the pathogenesis of fructose malabsorption is a matter of debate. The hydrogen production by colonic bacteria is used for diagnosis with the hydrogen breath test. However, the appropriate fructose test dose for correct diagnosis is unclear. Subjects with fructose malabsorption show increased breath hydrogen levels and abdominal symptoms after fructose administration but do not report any symptoms when fructose is given together with glucose. This beneficial effect of glucose, however, cannot be explained yet but might be used for clinical care of these subjects.

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.

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.

Standard short-term diet ameliorates the lipid profile altered by a fructose-rich diet in rats

Markers of metabolic abnormalities are commonly found in rodents fed a fructose-rich diet. The purpose of this study was to determine whether the administration of a short-term standard diet to rats is able to improve the lipid profile altered by a fructose-rich diet. The male pups, immediately after birth, were divided in three groups according to the diet for 90 days. Standard diet: a standard diet for the whole experimental period; fructose (60% fructose-rich diet): fructose-rich diet during the entire experimental period; fructose/standard (FS): fructose-rich diet from the neonatal period up to 60 days of age and standard diet from 60 to 90 days of age. A fructose-rich diet from the neonatal period to 60 days reduced weight gain (P<0.05), as well as the weight of adipose tissues in all the regions analyzed (epididymal, mesenteric, retroperitoneal and posterior subcutaneous), and it altered the lipid profile (elevation of triglycerides, total cholesterol, low density lipoprotein (LDL) cholesterol and very low density lipoprotein (VLDL) cholesterol; P<0.05). When a standard diet was administered after the fructose-rich diet, it was able to partially reverse changes to the lipid profile, as total cholesterol levels were significantly different in all the groups (P<0.05), and triglyceride and VLDL cholesterol levels were similar between the control and FS group. In summary, a fructose-rich diet altered the lipid profile, and a standard diet can partially reverse the changed parameters in short term.

Management of diarrhea in HIV-affected infants and children

Globally, diarrhea is the second leading cause of death in children less than 5 years of age. HIV-infected and HIV-exposed uninfected (HEU) children are at high risk of dying from diarrhea and may be more susceptible to the highest risk enteric pathogens. This increased risk associated with HIV infection and HIV exposure is likely multifactorial. Factors such as immunosuppression, proximity to individuals more likely to be shedding pathogens, and exposure to antimicrobial prophylaxis may alter the risk profile in these children. Current international guidelines do not differentiate management strategies on the basis of whether children are infected or affected by HIV, despite likely differences in etiologies and consequences. Reducing diarrhea mortality in high HIV prevalence settings will require strengthening of HIV testing and treatment programs; improvements in water, sanitation and hygiene interventions targeted at HIV-affected households; and reconsideration of the use of empiric antimicrobial treatment of pathogens known to infect HIV-infected and HEU children disproportionately.

Fermentable oligosaccharides, disaccharides, monosaccharides and polyols: role in irritable bowel syndrome

Irritable bowel syndrome (IBS) was previously left poorly treated despite its high prevalence and cost. Over the past decade, significant research has been conducted providing new dietary strategies for IBS management. The 'low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet' has shown symptom improvement in 68-76% of patients. Randomized, controlled trials have now proven its efficacy. The diet, low in poorly absorbed and fermentable carbohydrates, uses dietary restriction and re-challenge to determine individual tolerance to various short-chain carbohydrates. However there may be potential detrimental effects of the diet in the long term, due to potential changes to the gastrointestinal microbiota. Appropriate dietary education and management of the diet is imperative. Future research should focus on the relevance of changes to the microbiota and ways to liberalize the dietary restrictions.

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.

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.

Reduced prevalence of obesity in children with primary fructose malabsorption: a multicentre, retrospective cohort study

BACKGROUND

Studies in animals and in man have demonstrated that excessive consumption of fructose can cause all components of the metabolic syndrome.

OBJECTIVE

To investigate the impact of a condition resulting in decreased absorption of fructose, on obesity.

METHODS

In a multicentre study, we analyzed a cohort of paediatric patients with suspected primary fructose malabsorption (FM). Patients with chronic intestinal diseases were excluded. The final cohort comprised 628 patients.

RESULTS

302 patients were diagnosed with primary FM (48.1%). The proportion of obese patients was lower among FM patients, compared to non-FM patients (2.3 vs. 6.1%, P = 0.029). Logistic regression analysis with inclusion of various covariates showed that FM was negatively associated with obesity (OR 0.35, 95% CI [0.13; 0.97]). We discuss several mechanisms involving the metabolic, endocrine and gastrointestinal system.

CONCLUSIONS

Our data indicate that primary FM is negatively associated with childhood obesity.

Effects of a D-xylose preload with or without sitagliptin on gastric emptying, glucagon-like peptide-1, and postprandial glycemia in type 2 diabetes

OBJECTIVE

Macronutrient "preloads" can reduce postprandial glycemia by slowing gastric emptying and stimulating glucagon-like peptide-1 (GLP-1) secretion. An ideal preload would entail minimal additional energy intake and might be optimized by concurrent inhibition of dipeptidyl peptidase-4 (DPP-4). We evaluated the effects of a low-energy D-xylose preload, with or without sitagliptin, on gastric emptying, plasma intact GLP-1 concentrations, and postprandial glycemia in type 2 diabetes.

RESEARCH DESIGN AND METHODS

Twelve type 2 diabetic patients were studied on four occasions each. After 100 mg sitagliptin (S) or placebo (P) and an overnight fast, patients consumed a preload drink containing either 50 g D-xylose (X) or 80 mg sucralose (control [C]), followed after 40 min by a mashed potato meal labeled with (13)C-octanoate. Blood was sampled at intervals. Gastric emptying was determined.

RESULTS

Both peak blood glucose and the amplitude of glycemic excursion were lower after PX and SC than PC (P < 0.01 for each) and were lowest after SX (P < 0.05 for each), while overall blood glucose was lower after SX than PC (P < 0.05). The postprandial insulin-to-glucose ratio was attenuated (P < 0.05) and gastric emptying was slower (P < 0.01) after D-xylose, without any effect of sitagliptin. Plasma GLP-1 concentrations were higher after D-xylose than control only before the meal (P < 0.05) but were sustained postprandially when combined with sitagliptin (P < 0.05).

CONCLUSIONS

In type 2 diabetes, acute administration of a D-xylose preload reduces postprandial glycemia and enhances the effect of a DPP-4 inhibitor.

Funktions- und Laboruntersuchungen

Zur Analyse abgeatmeter Gase muss endexspiratorische Luft gewonnen werden, ohne Vermischung mit frühexspiratorischer Luft (sonst Korrektur mit Messung des CO2-Partialdrucks, s. unten). Ältere Kinder blasen nach Anhalten der Atmung über 15 s durch tiefe Ausatmung über einen Strohhalm endexspiratorische Luft in ein Glasröhrchen, das dann luftdicht verschlossen wird (Vacutainer), oder über ein Mundstück oder eine Maske direkt in ein H2-Messgerät oder in Beutel. Bei Säuglingen und Kleinkindern kann mit einer Maske oder einer Sonde, die bis zum nasopharyngealen Übergang vorgeschoben wird, mit einer Spritze atemsynchron exspiratorische Luft abgesaugt und in Vacutainer oder direkt in das Messgerät eingegeben werden. In Vacutainern sind Proben über mehr als 30 Tage stabil und können auch zur Analyse verschickt werden.

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.