Breath Hydrogen Test in Lactose Malabsorption

Lactose is the most important source in mammalian milk. In normal children, Lactose is hydrolyzed by lactase, and directly absorbed into bloodstream by an active transport mechanism. The term of lactose malabsorption is reserved to patients in whom impaired intestinal lactose hydrolysis and uptake has been proven by an appropriate test. The severity of lactose malabsorption and the extent of symptoms vary widely and are the results of several factors such as the amount of ingested lactose, gastric emptying time, intestinal transit time, and colonic flora. The diagnosis of lactose malabsorption is based on clinical findings and the results of appropriate tests. The breath hydrogen test has obvious advantages for pediatric population because it is painless, non-invasive, sensitive and specific. In the absence of bacterial colonization in the small intestine, the elevation of the concentration of hydrogen in the expired air implies the arrival of lactose in the colon. The increasing respiratory excretion of hydrogen is indicative of a deficit of lactase in enterocyte brush border. This test can also be used to show the existence of bacterial growth. Dietary fiber, some drugs, preparation for colonoscopy, colonic pH, and diarrhea can influence the result of breath hydrogen test.

Probiotic treatment in children with lactose intolerance – An open labeled the one group pre-test post-test experimental study

Background Lactose intolerance is the most common disorder ofintestinal carbohydrate digestion. Probiotic that contains the cor-rect strain in appropriate amount can be used as an alternativedietary for lactose intolerance patients.Objective This study was designed to describe the role of probioticin relieving lactose intolerance symptoms in children consumedfull-cream milk.Methods This study was a clinical trial. Inclusion criteria was chil-dren aged 12-14 years old, had a good nutrition and health status,with positive breath hydrogen test (BHT) result and lactose intoler-ance symptom(s), and their parents gave consent. Forty-two chil-dren were included. All subjects consumed one glass (200 ml) offull-cream milk twice a day for 21 days and recorded intolerancesymptoms. Probiotic was added from 8 th to 21 st day in their milk,and responses of treatment were evaluated by scoring system(based on borborigmic, flatulence, abdominal bloating, nausea andvomiting, abdominal pain, and diarrhea symptoms). At the end ofstudy they were undergone second BHT examination.Results There were decreasing mean score rates at 7 th day (pre)13.8 (SD 5.5) compared with 7.5 (SD 3.5) at 14 th day (after) andwas statistically significant (P<0.001). Mean score rate at 7 th day(pre) 13.8 (SD 5.5) compared with 21 st day (after) was 0.119 (SD0.55) and was statistically significant (P<0.001). At the end of study,only 2 subjects showed clinical signs of lactose intolerance. Thirty-six subjects had normal BHT result at 21 st day and was statisti-cally significant (P<0.001).Conclusion Two weeks administration of probiotic could relievelactose intolerance symptoms in children consumed full-cream milk

Lactose malabsorption based on breath hydrogen test in children with recurrent abdominal pain

Background Recurrent abdominal pain (RAP) is common amongschool-age children. Previous studies found that lactose malab-sorption has an important role in RAP in children. Up to date, dataon the prevalence of lactose malabsorption in children with RAPin Indonesia has not been available.Objective To elicit the prevalence of RAP and lactose malabsorption inchildren with RAP, and to determine associated foods that cause RAPin children with and without lactose malabsorption, the frequency oflactose intolerance during breath hydrogen test (BHT), and also theonset and duration of the symptoms after a lactose load.Methods This was a cross-sectional study conducted on juniorhigh school students who suffered from recurrent abdominal pain.Results Of 1054 students screened, 157 (14.9%) fulfilled the Apley’scriteria for RAP. Of 157, 85 children were enrolled and underwentBHT. Fifty five of them (65%) were girls. Lactose malabsorptionwas found in 68 (80%) subjects. Milk and yogurt were the mostfrequent products that cause symptoms of RAP in our subjectswho mostly (80%) were malabsorber. Lactose intolerance duringBHT was found in 69 (81%) children. Symptoms appeared in 30minutes after lactose ingestion, and the most frequent symptomwas abdominal pain (44%). Lactose intolerance symptoms disap-peared in about 15 hours.Conclusions The prevalence of RAP in children aged 12-14 yearswas 14.9%. The prevalence of lactose malabsorption in childrenwith RAP was 80%. Milk and yogurt were the most frequent productsthat cause symptoms of RAP in our subjects who mostly weremalabsorbers. The frequency of lactose intolerance during BHTwas 81%, and the symptoms lasted within approximately 15 hours

Intestinal fructose transport and malabsorption in humans

Fructose is a hexose sugar that is being increasingly consumed in its monosaccharide form. Patients who exhibit fructose malabsorption can present with gastrointestinal symptoms that include chronic diarrhea and abdominal pain. However, with no clearly established gastrointestinal mechanism for fructose malabsorption, patient analysis by the proxy of a breath hydrogen test (BHT) is controversial. The major transporter for fructose in intestinal epithelial cells is thought to be the facilitative transporter GLUT5. Consistent with a facilitative transport system, we show here by analysis of past studies on healthy adults that there is a significant relationship between fructose malabsorption and fructose dose ( r = 0.86, P < 0.001). Thus there is a dose-dependent and limited absorption capacity even in healthy individuals. Changes in fructose malabsorption with age have been observed in human infants, and this may parallel the developmental regulation of GLUT5 expression. Moreover, a GLUT5 knockout mouse has displayed the hallmarks associated with profound fructose malabsorption. Fructose malabsorption appears to be partially modulated by the amount of glucose ingested. Although solvent drag and passive diffusion have been proposed to explain the effect of glucose on fructose malabsorption, this could possibly be a result of the facilitative transporter GLUT2. GLUT5 and GLUT2 mRNA have been shown to be rapidly upregulated by the presence of fructose and GLUT2 mRNA is also upregulated by glucose, but in humans the distribution and role of GLUT2 in the brush border membrane are yet to be definitively decided. Understanding the relative roles of these transporters in humans will be crucial for establishing a mechanistic basis for fructose malabsorption in gastrointestinal patients.

Genotyping of the Lactase-Phlorizin Hydrolase −13910 Polymorphism by LightCycler PCR and Implications for the Diagnosis of Lactose Intolerance

Background: Hypolactasia and lactose intolerance are common conditions worldwide. Hypolactasia seems to be strongly correlated with genotype C/C of the genetic variant C→T−13910 upstream of the lactase phlorizin hydrolase (LPH) gene. We developed a rapid genotyping assay for LPH C→T−13910 and investigated the relationship of positive lactose breath hydrogen test (LBHT) results suggesting lactose intolerance with LPH C→T−13910 genotype. Methods: Using automated DNA purification on the MagNA Pure LC and real-time PCR on the LightCycler, we examined samples from 220 individuals to estimate genotype frequencies; we then determined LPH C→T−13910 genotype in samples from 54 Caucasian patients with a positive LBHT result and symptoms of lactose intolerance. Results: Genotyping of 220 individuals revealed frequencies of 21.4%, 41.8%, and 36.8% for genotypes C/C, C/T, and T/T. Of the patients with positive LBHT results, only 50% had the C/C genotype suggestive of primary adult hypolactasia in our study population. The other patients had various degrees of secondary hypolactasia or symptoms of lactose intolerance. Patients with C/C genotype had a mean (SD) peak H2 increase in the LBHT [108 (58) ppm] that was significantly higher than in patients with the C/T [65 (54) ppm] and T/T [44 (34) ppm] genotypes. Conclusions: The new real-time PCR assay provides a rapid, labor-saving means for the genotyping of LPH C→T−13910. Use of the assay may assist in differentiating patients with primary hypolactasia from those with secondary hypolactasia and lactose intolerance, who may need further clinical examinations to diagnose their underlying primary diseases.