The role of small intestinal bacterial overgrowth and false positive diagnosis of lactose intolerance in southwest Hungary-A retrospective observational study.

Péter Varjú,Birgit Ystad,Noémi Gede,József Czimmer,Péter Hegyi,Dániel Pécsi,Elizabeth S Mayne

doi:10.1371/journal.pone.0230784

Péter Varjú, Birgit Ystad + Show 5 more

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https://doi.org/10.1371/journal.pone.0230784

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Abstract

BackgroundLactose intolerance is a frequent gastrointestinal disease affecting 47% of the Eastern European population. Small intestinal bacterial overgrowth (SIBO) leads to carbohydrate malabsorption and therefore to false results during lactose breath and tolerance tests.ObjectivesWe aimed to assess the prevalence of lactose maldigestion and intolerance in Hungary and to investigate the role of combined diagnostic method and testing for SIBO in reducing false results.MethodsWe retrospectively analyzed data from 264 adult symptomatic patients who underwent 50g lactose breath and tolerance tests in parallel over a one-year period at our center. A ≥20 ppm elevation of H2 or less than 1.1 mmol/l rise of blood glucose was diagnostic for lactose maldigestion. Patients with maldigestion who had symptoms during the test were defined as lactose intolerant. Patients with an early (≤90 min) significant (≥20 ppm) rise of H2 during lactose and/or lactulose breath tests were determined to have SIBO. Patients with slow/rapid oro-cecal transit and inappropriate preparation before the test were excluded.Results49.6% of the 264 patients had lactose maldigestion, and 29.5% had lactose intolerance. The most frequent symptom was bloating (22.7%), while 34.8% of the study population and 60% of the symptomatic patients had SIBO. In 9.1% and 9.8% of the patients, the lactose breath and tolerance test alone gave false positive result compared with the combined method. SIBO was present in 75% of the false positives diagnosed with breath test only.ConclusionsThe prevalence of lactose intolerance is lower in Hungary compared to the Eastern European value (29.5% vs 47%), so it is worth performing a population-based prospective analysis in this area. A combination of lactose breath and tolerance tests and the careful monitoring of results (with early H2 rise, lactulose breath test, etc.) can decrease the false cases caused by e.g. SIBO.

Highlights

Lactose intolerance (LI) is a clinical syndrome characterized by abdominal symptoms after ingestion of lactose-containing products caused by lactose maldigestion (LM) [1,2,3]
The prevalence of lactose intolerance is lower in Hungary compared to the Eastern European value (29.5% vs 47%), so it is worth performing a population-based prospective analysis in this area
A combination of lactose breath and tolerance tests and the careful monitoring of results can decrease the false cases caused by e.g. Small intestinal bacterial overgrowth (SIBO)

Summary

Introduction

Lactose intolerance (LI) is a clinical syndrome characterized by abdominal symptoms after ingestion of lactose-containing products caused by lactose maldigestion (LM) [1,2,3]. 47% of the Eastern European population is affected; LI is more common in Asia, Africa, and South America. It affects males and females [2, 6]. In most studies and at most centers, only one of the last two methods (LBT or LTT) is used, resulting in higher rates of incorrect diagnosis caused by SIBO, for example, which can lead to carbohydrate malabsorption and to false positive results during the LBT and LTT. Lactose intolerance is a frequent gastrointestinal disease affecting 47% of the Eastern European population. Small intestinal bacterial overgrowth (SIBO) leads to carbohydrate malabsorption and to false results during lactose breath and tolerance tests

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