Measurement of breath hydrogen and methane, together with lactase genotype, defines the current best practice for investigation of lactose sensitivity

Ann Clin Biochem 2008;45:50-58
© 2008 Association for Clinical Biochemistry


This Article

Figures Only

Full Text

Full Text (PDF)

Alert me when this article is cited

Alert me if a correction is posted

Email this article to a friend

Similar articles in this journal

Similar articles in PubMed

Alert me to new issues of the journal

Download to citation manager

Citing Articles
Citing Articles via Google Scholar
Google Scholar

Articles by Waud, J. P

Articles by Campbell, A. K
Search for Related Content

PubMed Citation
Social Bookmarking

What’s this?

Original Article

Jonathan P Waud 1,
Stephanie B Matthews 1 and
Anthony K Campbell 2 

1 Department of Medical Biochemistry and Immunology, Llandough Hospital, Cardiff and Vale NHS Trust, Llandough, Vale of Glamorgan, South Wales, Cardiff CF64 2XX;
2 Department of Medical Biochemistry and Immunology, Cardiff University, Tenovus Building, Heath Park Campus, Heath Park, Cardiff CF14 4XN, UK

Corresponding author: Prof Anthony K Campbell. Email: campbellak{at}

Background: Currently, there is no ‘gold standard’ for detecting patients with sensitivity to lactose. Biochemical investigation by a breath hydrogen test alone detects <50% cases. Breath methane and symptoms are not recorded as standard practice. The clinical value of analysing C/T13910 and G/A22018 polymorphisms,strongly associated with lactose sensitivity, has not been established.

Methods: Two hundred and ten patients with unexplained gut and systemic symptoms and controls were challenged with 50 g lactose. Breath hydrogen and methane were measured and symptoms recorded. All were genotyped for two polymorphisms, C/T13910 and G/A22018.

Results: CC13910/GG22018 in 14.5%, CT13910/GA22018 in 39% and TT13910/AA22018 in 46.5%. One hundred percent of CC13910/GG22018 were lactose sensitive having a breath hydrogen >20 ppm within 6 h and symptoms. But the breath hydrogen test lacked sensitivity and specificity in the other groups. There was elevated breath hydrogen in 21% of CT13910/GA22018 and 15% of TT13910/AA22018 by 6 h,whereas 17 and 30.9% had elevated breath methane alone. Breathmethane and breath hydrogen with clinical symptoms improvedsensitivity and specificity, increasing detection of lactosesensitivity in genotypes CT/GA and TT/AA from <50 to >75%.

Conclusions: The data presented define the current best practice for theclinical identification of lactose sensitivity. Patients werefirst genotyped. Those identified as CC with symptoms shouldimmediately undertake a 12-week lactose-free diet. Those identifiedas CT or TT should undertake a breath hydrogen and methane test.Those positive for hydrogen or methane along with symptoms orwith symptoms only, should also undertake a lactose-free diet.Those with high hydrogen without symptoms should be investigatedfor causes other than lactose sensitivity.

CiteULike    Complore    Connotea    Digg    Reddit    Technorati    What’s this?