Influencing factors on the severity of clinical and laboratory manifestations of carbohydrate malabsorption syndrome in early-aged children with rotavirus infection

Purpose — to determine the role of the lactase gene MCM6 allelic polymorphism 13910 C/T and the concomitant food allergy (FA) and atopic dermatitis (AD) on the formation of carbohydrate malabsorption syndrome manifestations in early-aged children with rotavirus infection (RVI). Materials and methods. 60 children aged 1–24 months with RVI were examined. The determination of single nucleotide polymorphism 13910 C/T of the MCM6 gene was performed by real-time polymerase chain reaction and the content of total Ig E in serum was determined by enzyme immunoassay for all children on the day of hospitalization. Total amount of carbohydrates in feces (Benedict's test) and the level of lactose in feces (Malfatti's test) were also determined in the dynamics of the disease (on the 3rd, 5th, 7th, 10th day). The analysis of the carbohydrate malabsorption syndrome clinical and laboratory signs was carried out in subgroups depending on the genotype 13910 C/T of the MCM6 gene and concomitant allergic pathology. Results. No significant differences were found in the maximum daily frequency of diarrhea, its duration and the frequency of intestinal colic and flatulence registration in children with genotypes C/C, C/T and T/T -13910 of the MCM6 gene (p>0.05). There was no statistically significant difference in the total level of carbohydrates and lactose in feces at all stages of the disease (p>0.05 on the 3rd, 5th, 7th, 10th). Children with concomitant FA and AD had 1.3 and 2 times higher daily frequency of liquid bowel movements during the height of the disease (p<0.05 on the 5th and 7th days, respectively), 1.3 times longer diarrhea (p<0.05), 1.6 and 1.8 times higher incidence of flatulence and intestinal colic (p<0.05). These children had 3 and 3.3 times higher Benedict's test values (p<0.01), as well as 3 and 2.5 times higher Malfatti's test values (p<0.01; p<0.05, respectively) on the 3rd and 5th days of RVI, respectively, than in patients without allergies, with a gradual decrease in this difference during the period of convalescence (p>0.05 on the 10th day). Conclusions. The allelic polymorphism 13910 C/T of the MCM6 gene does not affect the degree of oligosaccharide metabolism disorders in the intestines in early-aged children with RVI. Against the background of concomitant food allergy and atopic dermatitis in children with RVI, there are more pronounced laboratory signs of carbohydrate malabsorption, and, as a consequence, diarrhea more pronounced during the height of the disease with a higher incidence of flatulence and intestinal colic. The research was carried out in accordance with the principles of the Helsinki declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the author. Key words: rotavirus infection, early-aged children, carbohydrate malabsorption syndrome, lactase gene polymorphism, food allergy, atopic dermatitis.

Pathogenetic role of intestinal microflora in carbohydrate malabsorption syndrome in early-aged children with rotavirus infection

The aim is to evaluate the effect of metabolic activity of intestinal microflora on laboratory manifestations of carbohydrate malabsorption syndrome in early-aged children with rotavirus infection by studying the main intestinal metabolites – short-chain fatty acids in faeces. Materials and methods. 60 breastfed children with rotavirus infection aged 1–24 months were examined. The total amount of carbohydrates in faecal samples was determined using Benedict’s test, and the detection of short-chain fatty acids in faeces was carried out using liquid chromatography in the dynamics of the disease – on the 3rd, 5th and 10th day. Results. It was established, that the amount of reducing sugars in faeces decreased with the increasing concentration of intestinal microflora metabolites during the entire period of rotavirus infection. In patients with ≤0.5 % level of carbohydrates in faeces, the total content of short-chain fatty acids was the highest and exceeded by 2.0, 1.8 and 1.7 times the indicators of children with Benedict’s test values >0.5 % on the 3rd, 5th and 10th days of the disease, respectively (p < 0.05). A decrease in the metabolic activity of the intestinal microbiota in the above category of children occurred mainly due to a deficiency in the production of acetic and propionic acids (P < 0.05). In the acute period of the disease, an imbalance in the intestinal microbiota infrastructure was noted towards a deficiency of obligate anaerobes that was expressed in a decrease in the anaerobic index (P < 0.05). The severity of these disorders influenced the severity of carbohydrate malabsorption: with an increase in the level of undigested sugars in faeces >0.5 %, the anaerobic index values were 3 and 5 times lower than at a carbohydrate level ≤0.5 % on the 3rd and 5th days of the disease, respectively (P < 0.05). Conclusions. It has been found that early-aged children with rotavirus infection have structural and functional disorders of the intestinal microflora, which influence the severity of carbohydrate malabsorption syndrome. The lower the saccharolytic activity of intestinal bacteria, the more pronounced the manifestations of this syndrome during the entire period of the disease.

Laboratory signs of carbohydrate malabsorption in early age children with rotavirus infection

The aim – to determine the laboratory manifestations of carbohydrate malabsorption syndrome in the dynamics of rotavirus infection in early age children and to identify the factors that influence its severity. Materials and methods. The study included 60 breastfed children aged 1–24 months with rotavirus infection, who underwent pH-metry of feces, semi-quantitative determination of total carbohydrates (Benedict’s method), lactose (Malfatti method) and glucose (test systems Glucophan) in feces on the 2nd, 3rd, 5th, 7th and 10th days of the disease. Results. Carbohydrate malabsorption syndrome was observed in 98.3% of patients. The level of fecal carbohydrates increased on the second-third day to a clinically significant 0.50 [0.20; 1,50] %, reached its maximum in the midst of the disease – from the fifth to the seventh day (0.75 [0.50; 1.65] % and 0.87 [0.40; 1.65] %, respectively), decreasing during convalescence to 0.50 [0.20; 1.50] % (P < 0.05 relative to the 10th day), but remained elevated in 81.7 % of patients (P < 0.05 relative to healthy children). Lactase deficiency and glucose malabsorption (P < 0.05 relative to healthy children) were observed throughout the RVI period. At all stages of RVI there was a strong direct correlation between the total level of carbohydrates and lactose in the feces (on the second, third, fifth, seventh and tenth days r = 0.91; r = 0.86; r = 0.91; r = 0.89, respectively). The age dependence of the severity of laboratory indicators of carbohydrate malabsorption was established. Children in the first 6 months had the highest maximum levels of carbohydrates and fecal lactose – 1.75 [1.00; 2.00] % and 3.50 [2.00; 4.00] + respectively (P < 0.05 relative to 12–24 months children) and significantly higher values of these indicators in the dynamics of RVI (P < 0.05 relative to 12–24 months children) for the second-third, fifth and the tenth day). Children with concomitant food allergies, atopic dermatitis and iron deficiency anemia had 2.0 and 1.5 times higher maximum levels of carbohydrates and lactose in the stool, respectively (P < 0.05), as well as higher values of these indicators in the dynamics of the disease – on the third and fifth days (P < 0.05). Conclusions. The vast majority of young patients with rotavirus infection have carbohydrate malabsorption syndrome, which occurs from the first days of the disease and is most pronounced on the fifth to seventh day (P < 0.05 relative to the 10th day), realized mainly due to lactase deficiency. The most pronounced carbohydrate malabsorption syndrome and lactase deficiency in the dynamics of the disease are present in children of the first six months of life. Factors that increase the severity of carbohydrate malabsorption due to secondary lactase deficiency in the acute period of rotavirus infection are concomitant food allergies, atopic dermatitis and iron deficiency anemia.

Hydrogen Breath Tests: Are They Really Useful in the Nutritional Management of Digestive Disease?

Background: Carbohydrate malabsorption is a frequent digestive problem associated with abdominal pain, bloating and diarrhea. Hydrogen breath testing (BT) represents the most reliable and validated diagnostic technique. The aim of this manuscript was to clarify the usefulness of BTs in the nutritional management of these disorders. Methods: A literature search for BT related to carbohydrate malabsorption was carried out using the online databases of Pubmed, Medline and Cochrane. Results: Lactose BT showed good sensitivity and optimal specificity for lactose malabsorption. However, an accurate diagnosis of lactose intolerance should require blind lactose challenge although this method is difficult to utilize in clinical practice. Regarding dose-depending fructose and sorbitol malabsorption, BTs could not add diagnostic advantage compared with a direct dietary intervention. In addition, carbohydrates are fundamental components of fermentable oligo-, di- and monosaccharides and polyols (FODMAPs). Before starting a low FODMAP diet, lactose BT should be suggested in a population with low prevalence of hypolactasia. Conclusions: BTs represent a valid and noninvasive technique in many digestive conditions. Regarding the management of carbohydrate intolerance, lactose BT can be recommended with some limitations. No sufficient evidence is available about the usefulness of BTs for other sugars in clinical practice.

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.

Impact of 24-h high and low fermentable oligo-, di-, monosaccharide, and polyol diets on markers of exercise-induced gastrointestinal syndrome in response to exertional heat stress

The study aimed to determine the effects of 24-h high (HFOD) and low (LFOD) fermentable oligo-, di-, monosaccharide, and polyol (FODMAP) diets before exertional heat stress on gastrointestinal integrity, function, and symptoms. Eighteen endurance runners consumed a HFOD and a LFOD (double-blind crossover design) before completing 2 h of running at 60% maximal oxygen uptake in 35 °C ambient temperature. Blood samples were collected before and after exercise to determine plasma cortisol and intestinal fatty acid binding protein (I-FABP) concentrations, and bacterial endotoxin and cytokine profiles. Breath hydrogen (H2) and gastrointestinal symptoms (GIS) were determined pre-exercise, every 15 min during, and in recovery. No differences were observed for plasma cortisol concentration between diets. Plasma I-FABP concentration was lower on HFOD compared with LFOD (p = 0.033). A trend for lower lipopolysaccharide binding protein (p = 0.088), but not plasma soluble CD14 (p = 0.478) and cytokine profile (p > 0.05), responses on HFOD was observed. A greater area under the curve breath H2 concentration (p = 0.031) was observed throughout HFOD (mean and 95% confidence interval: HFOD 2525 (1452–3597) ppm·4 h−1) compared with LFOD (1505 (1031–1978) ppm·4 h−1). HFOD resulted in greater severity of GIS compared with LFOD (pre-exercise, p = 0.017; during, p = 0.035; and total, p = 0.014). A 24-h HFOD before exertional heat stress ameliorates disturbances to epithelial integrity but exacerbates carbohydrate malabsorption and GIS severity in comparison with a LFOD. Novelty Twenty-four-hour high FODMAP diet ameliorated disturbances to gastrointestinal integrity. Twenty-four-hour high FODMAP diet results in greater carbohydrate malabsorption compared with low FODMAP diet. Incidence of GIS during exertional heat stress were pronounced on both low and high FODMAP diets, but greater GIS severity was observed with high FODMAP diet.

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 [...]

Stool Reducing Sugars and Stool pH Are Poor Screening Tests for Intestinal Disaccharidase Deficiencies in Children

Background Tests for stool reducing sugars and stool pH are ordered for children with osmotic diarrhea to screen for carbohydrate malabsorption. Methods We compared the results of the two screening tests, stool reducing sugars and stool pH, with a more definitive result from an intestinal tissue disaccharidase activity assay ordered for pediatric patients (&lt;18 years old). Overall, 159 patients had results for tissue disaccharidase and stool reducing sugars, but only 115 had additional results of stool pH. Forty-six of the 159 patients had mild, moderate, or severe disaccharidase deficiencies. The sensitivity and specificity of the screening tests were calculated for individual disaccharidase deficiencies. In addition, trends of abnormal tissue disaccharidase, stool reducing sugars, and stool pH results were examined in different age groups. Results The sensitivities for stool reducing sugars and stool pH were 9% to 28% and specificities were 74% to 81% for individual disaccharidase deficiencies. Infants (0 years of age) had the highest percentage of abnormal results across all three tests; however, the positive predicative values were 54% and 50% for stool reducing sugars and stool pH, respectively. Conclusions The screening tests, stool reducing sugars and stool pH, had low sensitivity compared with results of measured tissue disaccharidase activity in pediatric patients. Infants had the highest percentage of abnormal results for all three tests, but the screening tests still performed poorly in that age group. This study suggests that stool reducing sugars and stool pH should not be used as screening tests for carbohydrate malabsorption due to disaccharidase deficiencies in pediatric patients.