Lactose Malabsorption Testing in Daily Clinical Practice: A Critical Retrospective Analysis and Comparison of the Hydrogen/Methane Breath Test and Genetic Test (C/T-13910Polymorphism) Results

Abstract

The aim of this study was to establish a retrospective evaluation and comparison of the hydrogen/methane (H2/CH4) breath test and genetic test (C/T−13910 polymorphism) results in lactose malabsorption testing. In total 263 consecutive patients with suspected lactose malabsorption were included in this study. They underwent the H2/CH4 breath test following the ingestion of 50 g lactose and were tested for the C/T−13910 polymorphism. In total 51 patients (19.4%) had a C/C−13910 genotype, indicating primary lactose malabsorption. Only 19 patients (7.2%) also had a positive H2/CH4 breath test. All in all 136 patients (51.69%) had a C/T−13910 and 76 patients (28.91%) a T/T−13910 genotype, indicating lactase persistence. Four patients (1.5%) with the C/T−13910 genotype and one patient (0.4%) with the T/T−13910 genotype had a positive H2/CH4 breath test result, indicating secondary lactose malabsorption. Cohen's Kappa measuring agreement between the two methods was 0.44. Twenty patients (7.6%) with a positive H2/CH4 peak within 60 minutes after lactose ingestion were classified as patients with lactose-dependent small intestinal bacterial overgrowth (SIBO). In conclusion, only moderate agreement between the breath test and the genetic test was shown. Secondary lactose malabsorption as well as preanalytical limitations of the combined H2/CH4 breath test procedure can cause discrepant results. This trial is registered with K-42-13.

Laktózintolerancia: a laktázgén C/T-13910 polimorfizmusának és a hidrogénkilégzési teszt pontosságának retrospektív kiértékelése gasztroenterológiai szakrendelésen

“…Az ausztriai Grazban 153 betegben a CC genotípus aránya 24,1% volt [19], Lengyelországban 58 eset 26%-a [20], egy másik tanulmányban 38% [21], egy másik ausztriai dolgozatban 263 beteg 19,4%-a [22]. Az ará-nyok különbségeiben szerepe van a lakosság származási hátterének és az etnikumok keveredésének.…”

Refining small intestinal bacterial overgrowth diagnosis by means of carbohydrate specificity: a proof-of-concept study

“…After determining baseline breath H 2 /CH 4 concentrations, fructose or sorbitol was given in a dose of 25 g and 12.5 g, respectively, dissolved in 200 ml of water [Eisenmann et al 2008]. Based on former studies [Eisenmann et al 2008;Enko et al 2014Enko et al , 2015Goebel-Stengel et al 2014], patients with an early H 2 and/or CH 4 increase ⩾20 ppm above baseline within 60 minutes after sugar ingestion (i.e. small intestinal passage) were diagnosed with cs-SIBO.…”

“…Patients with a H 2 /CH 4 peak ⩾20 ppm within 60-120 minutes (i.e. colonic passage) were classified as malabsorbers [Eisenmann et al 2008;Enko et al 2014Enko et al , 2015Goebel-Stengel et al 2014]. Patients with abdominal symptoms during the first HMBT were able to perform further tests in a consecutive manner on the following workdays.…”

“…Compared with duodenal aspirate culture, glucose HMBT has a low sensitivity (42%) but a high specificity (84%) for the detection of SIBO [Erdogan et al 2015]. However, duodenal aspiration is cumbersome and has its own difficulties and limitations [Simren and Stotzer, 2006;de Lacy Costello et al 2013;Enko et al 2014], because many bacteria cannot be cultured and cell counts determined in vitro may not reflect the population in vivo [Gibson and Barrett, 2010]. Therefore HMBT has been suggested for SIBO diagnosis [de Lacy Castello et al 2013].…”

A laktózintoleranciáról: Múlt és jelen – I. rész

“…Az utóbbi években több módszert dolgoztak ki a kilélegzett metán mérésére (gázkromatográfi a, tömegspektrometria, lézerspektro-metria, szelektív ionfl uxus mérése). A hidrogén és metán együttes kimutatása is lehetséges [41].…”