Lactase persistence versus lactose intolerance: Is there an intermediate phenotype?

Dzialanski, Zbigniew; Bárány, Michael; Engfeldt, Peter; Magnuson, Anders; Olsson, Lovisa; Nilsson, Torbjörn

doi:10.1016/j.clinbiochem.2015.11.001

Cited by 30 publications

(15 citation statements)

References 16 publications

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“…Even in individual patient, the specificity and predictive value found may not be optimal to determine whether the patient's symptoms are attributable to lactose intolerance in a given moment, particularly when a heterozygous CT genotype is obtained. In a recent publication, this genotype has been described as an “intermediate” one, as higher levels of H 2 than in TT homozygous patients were found, which is consistent with the trend we show in our study. However, our result is limited as only one patient had a LCT ‐13910 TT genotype.…”

Section: Discussionsupporting

confidence: 93%

“…in older children. 8 However, despite the ease of obtaining samples (blood sample and even oral mucosa tissue), its use could be limited In a recent publication, this genotype has been described as an "intermediate" one, as higher levels of H 2 than in TT homozygous patients were found, 21 which is consistent with the trend we show in our study.…”

Section: Discussionsupporting

confidence: 91%

See 1 more Smart Citation

Concordance between Lactose Quick Test, hydrogen‐methane breath test and genotyping for the diagnosis of lactose malabsorption in children

Rojo

Jaime

Azócar

et al. 2017

Neurogastroenterology Motil

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Section: Discussionsupporting

confidence: 93%

Section: Discussionsupporting

confidence: 91%

Concordance between Lactose Quick Test, hydrogen‐methane breath test and genotyping for the diagnosis of lactose malabsorption in children

Rojo

Jaime

Azócar

et al. 2017

Neurogastroenterology Motil

View full text Add to dashboard Cite

show abstract

“…While the C/C 13910 genotype is associated with lactose malabsorption, the genotypes C/T and T/T are found in individuals with lactase persistence [ 2 ]. Heterozygotes carrying the C/T allele differ in their response to an oral lactose load, compared to C/C and T/T genotypes, suggesting an intermediate phenotype [ 32 ].…”

Section: Genetics and Epidemiology Of Lactose Intolerancementioning

confidence: 99%

Lactose intolerance and gastrointestinal cow’s milk allergy in infants and children – common misconceptions revisited

Heine

Al-Refaee

Bachina

et al. 2017

World Allergy Organization Journal

123

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Lactose is the main carbohydrate in human and mammalian milk. Lactose requires enzymatic hydrolysis by lactase into D-glucose and D-galactose before it can be absorbed. Term infants express sufficient lactase to digest about one liter of breast milk daily. Physiological lactose malabsorption in infancy confers beneficial prebiotic effects, including the establishment of Bifidobacterium-rich fecal microbiota. In many populations, lactase levels decline after weaning (lactase non-persistence; LNP). LNP affects about 70% of the world’s population and is the physiological basis for primary lactose intolerance (LI). Persistence of lactase beyond infancy is linked to several single nucleotide polymorphisms in the lactase gene promoter region on chromosome 2. Primary LI generally does not manifest clinically before 5 years of age. LI in young children is typically caused by underlying gut conditions, such as viral gastroenteritis, giardiasis, cow’s milk enteropathy, celiac disease or Crohn’s disease. Therefore, LI in childhood is mostly transient and improves with resolution of the underlying pathology. There is ongoing confusion between LI and cow’s milk allergy (CMA) which still leads to misdiagnosis and inappropriate dietary management. In addition, perceived LI may cause unnecessary milk restriction and adverse nutritional outcomes. The treatment of LI involves the reduction, but not complete elimination, of lactose-containing foods. By contrast, breastfed infants with suspected CMA should undergo a trial of a strict cow’s milk protein-free maternal elimination diet. If the infant is not breastfed, an extensively hydrolyzed or amino acid-based formula and strict cow’s milk avoidance are the standard treatment for CMA. The majority of infants with CMA can tolerate lactose, except when an enteropathy with secondary lactase deficiency is present.

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“… 1 – 3 In particular, lactose intolerance is the most common form of carbohydrate malabsorption and affects people of all ages. 4 – 6 The cause of this malabsorption is due to the deficiency of lactase, an enzyme that is normally present in the small intestine. Under normal conditions, after ingestion, lactose is hydrolyzed by lactase in the intestine (the highest activity of this enzyme is in jejunum) to form glucose and galactose.…”

Section: Introductionmentioning

confidence: 99%

Retrospective analysis of a lactose breath test in a gastrointestinal symptomatic population of Northeast Italy: use of (H2+2CH4) versus H2 threshold

Peron

Dall’Acqua

Sorrenti

et al. 2018

CEG

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BackgroundLactose malabsorption is normally evaluated by measuring exhaled H2 produced by intestinal flora, from unabsorbed lactose. However, differing microbiome composition can lead to the production of CH4 instead of H2; hence, some authors challenge the H2 method sensitivity and favor the evaluation of both intestinal gases.AimTo compare different approaches to usage of a lactose breath test for lactose malabsorption diagnosis, after medical evaluation of gastrointestinal symptoms.MethodsIn a retrospective observational study, we compared the 2 approaches in a population of 282 subjects in Northern Italy. Following oral lactose administration, exhaled samples were harvested every 30 minutes for 4 hours and prepared for H2 and CH4 analysis. Basal gas levels were subtracted from H2 and CH4 ppm and values at 4 hours and peaks were considered for analysis.ResultsApplying the standard methodology, which takes separately into consideration H2 and CH4 produced in the intestinal lumen, the results indicated that 11.7% of the patients were diagnosed “positive” for hypolactasia, differently from what was expected. Conversely, taking into consideration the sum of H2 and CH4, the percentage increased to 62.8%, closer to the expected one. No significant differences were found when comparing the 2 groups for age, gender, or symptoms. The sizable difference between the 2 approaches is likely linked to gut microbiome variability, and consequently the different production of the 2 gases, in the population.ConclusionThe threshold normally used for lactose breath test should be reconsidered and changed, merging H2 and CH4 stoichiometric values to increase sensitivity.

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Lactase persistence versus lactose intolerance: Is there an intermediate phenotype?

Cited by 30 publications

References 16 publications

Concordance between Lactose Quick Test, hydrogen‐methane breath test and genotyping for the diagnosis of lactose malabsorption in children

Concordance between Lactose Quick Test, hydrogen‐methane breath test and genotyping for the diagnosis of lactose malabsorption in children

Lactose intolerance and gastrointestinal cow’s milk allergy in infants and children – common misconceptions revisited

Retrospective analysis of a lactose breath test in a gastrointestinal symptomatic population of Northeast Italy: use of (H<sub>2</sub>+2CH<sub>4</sub>) versus H<sub>2</sub> threshold

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