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

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

OBJECTIVES

Abdominal pain remains one of the most common referral reasons to pediatric gastroenterology. Dietary intolerances are often considered but due to various factors are hardly pursued. We observed that diet review in large number of children with abdominal pain was high in sugary foods which led to food intolerance investigation and dietary intervention.

METHODS

A retrospective review was conducted of patients presenting with abdominal pain, diarrhea, or vomiting and negative GI evaluation, who underwent fructose breath testing. Patients younger than 20 years old who were seen between June 1, 2018 and March 1, 2021 were included. Statistical analysis was performed in R.

RESULTS

There were 110 pediatric patients during the study period who underwent fructose breath testing, with 31% male and 69% female. The average age was 12.14 ± 4.01 years, and the average BMI was 21.21 ± 6.12. Abdominal pain was the most common presenting symptom (74.5%) followed by diarrhea and vomiting. Seventy-seven patients (70%) had a positive fructose breath test and were diagnosed with dietary intolerance to fructose. The 56 (67.5%) of those patients experienced symptoms during the breath test. Forty-three patients improved with dietary intervention. Twenty-seven on low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet and 16 on other diets.

CONCLUSIONS

Based on analysis of our cohort of children with abdominal pain and high incidence of fructose intolerance as well as improvement in symptoms, following dietary changes, this condition should be considered and treated. Further investigation is needed to improve diagnostic testing but also into understanding mechanisms behind symptom presentation in this population.

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

Background

While role of ALDOB-related gene variants for hereditary fructose intolerance is well established, contribution of gene variants for acquired fructose malabsorption (e.g. SLC2A5, GLUT5) is not well understood.

Methods

Patients referred to fructose breath test were further selected to identify those having acquired fructose malabsorption. Molecular analysis of genomic DNA included (I) exclusion of 3 main ALDOB gene variants causing hereditary fructose intolerance and (II) sequencing analysis of SLC2A5 gene comprising complete coding region, at least 20 bp of adjacent intronic regions and 700 bp of proximal promoter.

Results

Among 494 patients, 35 individuals with acquired fructose malabsorption were identified based on pathological fructose-breath test and normal lactose-breath test. Thirty four of them (97%) had negative tissue anti-transglutaminase and/or deamidated gliadin antibodies in their medical records. Molecular analysis of SLC2A5 gene of all 35 subjects identified 5 frequent and 5 singular gene variants mostly in noncoding regions (promoter and intron). Allele frequencies of gene variants were similar to those reported in public databases strongly implying that none of them was associated with acquired fructose malabsorption.

Conclusions

Gene variants of coding exons, adjacent intronic regions and proximal promoter region of SLC2A5 gene are unlikely to contribute to genetic predisposition of acquired fructose malabsorption.

Significance of validated symptom assessment versus breath testing for malabsorption after lactose load in children

BACKGROUND AND OBJECTIVES

Lactose malabsorption and lactose-induced symptoms are poorly correlated, as shown by breath tests and various symptom assessment methods. Validated assessment is the key to overcome the limitations of biased symptom measurements. We characterized lactose-induced symptoms with the population-specific, validated paediatric carbohydrate perception questionnaire (pCPQ) and their correlation with the history of symptoms (HoS).

METHODS

A total of 130 patients with functional gastrointestinal symptoms underwent a lactose hydrogen breath and tolerance test (LBTT) allowing for a diagnosis of malabsorption (M+) and lactose sensitivity (S+). HoS indicative of lactose-induced symptoms (abdominal pain, nausea, bloating, flatulence, diarrhoea) in the 4 weeks preceding the test was determined using a validated questionnaire. The pCPQ was used to score lactose-induced symptoms.

MAIN RESULTS

The LBTT revealed 41 children (31.5%) with lactose malabsorption (M+), 56 (43.1%) with lactose sensitivity (S+) and 24 (18.5%) were M+/S+. Sensitivity correlated with HoS (P < 0.001), regardless of whether malabsorption was detectable. Malabsorption status did not correlate with HoS (NS). The odds of lactose sensitivity significantly increased when abdominal pain [odds ratio (OR) 3.5, confidence interval (CI) 1.6-7.8], nausea (OR 2.3, CI, 1.1-4.9) and flatulence (OR 3.1, CI 1.4-6.8) were reported in the 4 weeks preceding the LBTT. Symptoms after the lactose load were similar for M+/S+ and M-/S+, except for flatulence, which was more frequent in malabsorbers (P < 0.01).

CONCLUSION

Our findings fit well with the emerging view of the important role of a validated symptom assessment after a lactose load. The determination of symptoms may be more relevant than malabsorption for the clinical outcomes of paediatric patients with lactose-related gastrointestinal symptoms.

European guideline on indications, performance, and clinical impact of hydrogen and methane breath tests in adult and pediatric patients: European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Neurogastroenterology and Motility, and European Society for Paediatric Gastroenterology Hepatology and Nutrition consensus

Introduction

Measurement of breath hydrogen (H₂) and methane (CH₄) excretion after ingestion of test‐carbohydrates is used for different diagnostic purposes. There is a lack of standardization among centers performing these tests and this, together with recent technical developments and evidence from clinical studies, highlight the need for a European guideline.

Methods

This consensus‐based clinical practice guideline defines the clinical indications, performance, and interpretation of H₂‐CH₄‐breath tests in adult and pediatric patients. A balance between scientific evidence and clinical experience was achieved by a Delphi consensus that involved 44 experts from 18 European countries. Eighty eight statements and recommendations were drafted based on a review of the literature. Consensus (≥80% agreement) was reached for 82. Quality of evidence was evaluated using validated criteria.

Results

The guideline incorporates new insights into the role of symptom assessment to diagnose carbohydrate (e.g., lactose) intolerances and recommends that breath tests for carbohydrate malabsorption require additional validated concurrent symptom evaluation to establish carbohydrate intolerance. Regarding the use of breath tests for the evaluation of oro‐cecal transit time and suspected small bowel bacterial overgrowth, this guideline highlights confounding factors associated with the interpretation of H₂‐CH₄‐breath tests in these indications and recommends approaches to mitigate these issues.

Conclusion

This clinical practice guideline should facilitate pan‐European harmonization of diagnostic approaches to symptoms and disorders, which are very common in specialist and primary care gastroenterology practice, both in adult and pediatric patients. In addition, it identifies areas of future research needs to clarify diagnostic and therapeutic approaches.

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.

An Update on the Assessment and Management of Pediatric Abdominal Pain

Chronic abdominal pain is very common in children and adolescent and results in high personal and social costs. Most youth with chronic abdominal pain fulfill criteria for a functional abdominal pain disorder (FAPD) as defined by Rome criteria. These are complex conditions with a wide array of biological, psychological, and social factors contributing to the experience of pain. The purpose of the current review is to provide an overview of the pathophysiology of FAPDs and an up-to-date summary of the literature related to FAPDs in children and adolescents, with additional focus on several areas (eg, diet and probiotics) where patients and families frequently have questions or implement self-directed care. We also provide an approach to the assessment and treatment of pediatric FAPDs focusing on the robust literature regarding psychological interventions and much sparser literature regarding medication treatment.

Relevance of Methane and Carbon Dioxide Evaluation in Breath Tests for Carbohydrate Malabsorption in a Paediatric Cohort

OBJECTIVES

The relevance of methane measurement in breath tests for the detection of carbohydrate malabsorption in children is controversial. The need for correction for poor sample collection is disputed. We evaluated the relevance of methane/CO2 measurements for the diagnosis of paediatric carbohydrate malabsorption.

METHODS

A total of 132 breath tests (fructose: n = 54; lactose: n = 78) were performed in 91 children/adolescents with functional abdominal complaints. Breath samples were collected and analysed for hydrogen, methane, and CO2. Malabsorption was defined by a net increase over baseline of ≥20 parts per million (ppm) for hydrogen, ≥5 to ≥12 ppm for methane, and ≥10 to ≥15 ppm for hydrogen-plus-methane. The diagnosis was made before and after the use of a CO2-based correction factor (5.5% as the numerator). Hydrogen-based test results were compared with results obtained with other cut-off values.

RESULTS

Fifty-eight positive tests were obtained by hydrogen measurement (without CO2 correction). The addition of methane measurements did not significantly influence the test results (P > 0.05). Only under the use of extraordinary cut-offs (combined hydrogen-plus-methane smaller than ≥18 ppm) did the rate of malabsorbers increase significantly (P < 0.05). After CO2 correction, hydrogen ≥20 ppm was detected in 4 additional patients, but 1 patient lost the hydrogen-based diagnosis of malabsorption (Cohen kappa = 0.92).

CONCLUSIONS

Methane measurement did not significantly affect the detection rate of carbohydrate malabsorbers in children/adolescents with functional abdominal complaints when established cut-offs are used. The use of CO2 correction altered the diagnosis of malabsorption in a minority of patients but did not significantly alter overall test results.

Carbohydrate-induced gastrointestinal symptoms: development and validation of a test-specific symptom questionnaire for an adult population, the adult Carbohydrate Perception Questionnaire

OBJECTIVES

Carbohydrate intolerances may affect a majority of the worlds-population but there is no validated, test-specific assessment of carbohydrate-induced symptoms during breath tests. We aimed to develop and validate a questionnaire for evaluation and quantification of carbohydrate intolerance.

METHODS

A visual analog scale-questionnaire with five complaints (pain, nausea, bloating, flatulence, and diarrhea) was designed. The time frame of symptoms was 'current' (for baseline symptoms) and 'since filling out the last questionnaire'. Validity was determined in focus-group style interviews and during breath tests in an original (n = 342) and follow-up patient groups (n = 338).

RESULTS

The questionnaire had good face validity, content validity ratio according to Lawshe was 1. Intraclass correlation coefficients (n = 195; 30-min' interval) demonstrated excellent reliability (P < 0.001), Cohen's d (measure of effect size) was small (≤0.19 for each symptom). Convergent and discriminant validity were supported against patient interviews. Questionnaire-derived results highly correlated with a medical interview (P < 0.001; n = 338). Responsiveness to change was verified during breath tests despite small effect sizes (≤0.32). Additional cross-validation and external validation studies (follow-up in-house: n = 182; external: n = 156) demonstrated generalizability and identified relevant numbers of patients in whom there was no co-occurrence of carbohydrate malabsorption and intolerance.

CONCLUSIONS

The adult Carbohydrate Perception Questionnaire is a valid instrument for the assessment of gastrointestinal symptoms after carbohydrate ingestion with excellent psychometric properties. It allows standardized, test-specific diagnosis of carbohydrate intolerance and evaluation of the relation between malabsorption and intolerance. It shall be useful for future studies on treatment of carbohydrate intolerance.

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.

Development and validation of the paediatric Carbohydrate Perception Questionnaire (pCPQ), an instrument for the assessment of carbohydrate-induced gastrointestinal symptoms in the paediatric population

BACKGROUND

There is an unmet need for a validated, test-specific symptom questionnaire to evaluate carbohydrate perception during breath tests. Our aim was to develop and validate a questionnaire for the assessment of symptoms after a provocative carbohydrate load.

METHODS

After a literature search and initial focus group-style interviews, five relevant complaints were identified. Responses were given on a Likert-type faces scale with a language children use and understand. Reliability, validity and responsiveness to change were established by the implementation of the questionnaire during breath tests in 215 pediatric subjects. Correlation between the questionnaire and a medical interview by a pediatrician who was blinded to the results of the questionnaire (n = 19) was determined.

KEY RESULTS

The questionnaire had good face and content validity (Lawshe ratio = 1). Intraclass correlation coefficients for test-retest reliability (n = 116) demonstrated good repeatability (P < .001), and effect sizes were small (Cohen's d < 0.15 for all symptoms). Convergent validity and discriminant validity were supported according to the multitrait-multimethod matrix method. The results obtained by the questionnaire correlated highly with the result of the medical interview (P < .001; Fisher's exact test). Cronbach's alpha was 0.81. Responsiveness was verified for the whole patient group and subgroups with medium to high effect sizes.

CONCLUSIONS AND INFERENCES

The paediatric Carbohydrate Perception Questionnaire (pCPQ) is a simple, test-specific questionnaire for a pediatric population. It is a valid instrument with excellent psychometric properties to assess gastrointestinal symptoms after carbohydrate ingestion. The pCPQ can replace non-validated symptom assessment during carbohydrate breath tests and allows a standardized diagnosis of carbohydrate intolerance.

Valid Assessment of Carbohydrate Intolerance and the Need for a Distinction to Carbohydrate Malabsorption. Comment on "Roles of Lactose and Fructose Malabsorption and Dietary Outcomes in Children Presenting with Chronic Abdominal Pain.", Nutrients, 2019, 11, 3063

We have read with interest the recent paper by Posovszky and Roesler et al [1] that reports, based on the doctoral thesis by Dr. Roesler [2] [...].

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.