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

Authors Peron G, Dall'Acqua S, Sorrenti V, Carrara M, Fortinguerra S, Zorzi G, Buriani A

Received 28 January 2018

Accepted for publication 8 March 2018

Published 18 June 2018 Volume 2018:11 Pages 243—248


Checked for plagiarism Yes

Review by Single-blind

Peer reviewers approved by Dr Amy Norman

Peer reviewer comments 4

Editor who approved publication: Prof. Dr. Everson L.A. Artifon

Gregorio Peron,1 Stefano Dall’Acqua,1,2 Vincenzo Sorrenti,1,3 Maria Carrara,1 Stefano Fortinguerra,3 Giulia Zorzi,3 Alessandro Buriani3

Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy; 2Unir&d, Nutraceutical Laboratory, Padova, Italy; 3Maria Paola Belloni Center for Personalized Medicine, Data Medica Group, Synlab Limited, Padova, Italy

Background: Lactose 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.
Aim: To compare different approaches to usage of a lactose breath test for lactose malabsorption diagnosis, after medical evaluation of gastrointestinal symptoms.
Methods: In 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.
Applying 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.
Conclusion: The threshold normally used for lactose breath test should be reconsidered and changed, merging H2 and CH4 stoichiometric values to increase sensitivity.

Keywords: lactose malabsorption, intestinal malabsorption, hypolactasia, H2+2CH4 threshold

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