Effect of lactase on symptoms and hydrogen breath levels in lactose intolerance: A crossover placebo-controlled study

The absence of lactase in the intestinal villi due to mucosal injury or genetic factors causes undigested lactose to reach the colon where it is fermented. Lactose intolerance is diagnosed based on clinical symptoms like bloating, abdominal pain and flatulence, lactose hydrogen breath test (HBT), and lactose tolerance test. No Indian studies are available on the use of lactase supplements. The aim was to study the effect of lactase chewable tablets on clinical symptoms and hydrogen breath excretion in patients with lactose intolerance.

This was a randomized, double-blind, crossover placebo-controlled trial to study the effect of lactase tablets on symptoms and hydrogen breath levels in adults with lactose intolerance, confirmed by Lactose HBT. Clinical symptom severity was recorded using a visual analog scale, and HBT was performed every 30 min for 180 min. As it was a crossover design, the same patients were tested with both lactase and placebo, acting as their own controls with a washout period of 1 week between visits.

Forty-seven patients (mean age 33.6 years; 30 males) with lactose intolerance formed the study group. Clinical symptoms, mean clinical score (P < 0.05), and mean hydrogen breath levels (P < 0.05) were improved when the patients were given lactase. Reduction in cumulative hydrogen breath level over 180 min was 55% when patients received lactase compared to placebo.

Orally supplemented lactase enzyme significantly reduced the clinical symptoms and hydrogen breath excretion in patients with lactose intolerance.