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

Abstract

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/T 13910 and G/A 22018 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/T 13910 and G/A 22018 . Results: CC 13910 /GG 22018 in 14.5%, CT 13910 /GA 22018 in 39% and TT 13910 /AA 22018 in 46.5%. One hundred percent of CC 13910 / GG 22018 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 CT 13910 /GA 22018 and 15% of TT 13910 /AA 22018 by 6 h, whereas 17 and 30.9% had elevated breath methane alone. Breath methane and breath hydrogen with clinical symptoms improved sensitivity and specificity, increasing detection of lactose sensitivity in genotypes CT/GA and TT/AA from ,50 to .75%. Conclusions: The data presented define the current best practice for the clinical identification of lactose sensitivity. Patients were first genotyped. Those identified as CC with symptoms should immediately undertake a 12-week lactose-free diet. Those identified as CT or TT should undertake a breath hydrogen and methane test. Those positive for hydrogen or methane along with symptoms or with symptoms only, should also undertake a lactose-free diet. Those with high hydrogen without symptoms should be investigated for causes other than lactose sensitivity.

Quantifying the ‘hidden’ lactose in drugs used for the treatment of gastrointestinal conditions

“…Ideally, in these groups of patients, tests to diagnose lactose intolerance should be carried out to aid both dietary advice and the prescription of medications. 19 This work focuses on a selection of formulations available in the UK for the treatment of GI diseases; however, we are aware that certain drugs, for example, Pentasa, Nexium, Asacol and Omeprazole are manufactured with similar constituents in the US and Australia. Adult-type hypolactasia is a global problem, with varying severity based on ethnic origin.…”

Update on diagnostic value of breath test in gastrointestinal and liver diseases

“…Furthermore, Methane testing has also potentially contributed towards an increment in sensitivity of lactose BT [18] . Methane production is prevalent in 36%50% of healthy subjects in comparison with hydrogen which is more pervasive [1921] .…”

Adult Lactose Digestion Status and Effects on Disease

“…More practical indirect tests based on failure of rise of blood glucose (lactose tolerance test; measure of absorbed glucose) or a specific increase of measured breath hydrogen (measure of bacterial metabolism of maldigested lactose) after oral lactose loading are applied to clinical evaluation of lactose maldigestion. It is also used to evaluate lactose intolerance through various symptom scores at the time of testing (21)(22)(23). These indirect tests have been validated against both intestinal biopsies (24,25) as well as against (at least) the north European C/T-13910 polymorphism for lactase production (26).…”