Four-sample lactose hydrogen breath test for diagnosis of lactose malabsorption in irritable bowel syndrome patients with diarrhea

Abstract

Aim: To validate 4-sample lactose hydrogen breath testing (4SLHBT) compared to standard 13-sample LHBT in the clinical setting.

Methods: Irritable bowel syndrome patients with diarrhea (IBS-D) and healthy volunteers (HVs) were enrolled and received a 10 g, 20 g, or 40 g dose lactose hydrogen breath test (LHBT) in a randomized, double-blinded, controlled trial. The lactase gene promoter region was sequenced. Breath samples and symptoms were acquired at baseline and every 15 min for 3 h (13 measurements). The detection rates of lactose malabsorption (LM) and lactose intolerance (LI) for a 4SLHBT that acquired four measurements at 0, 90, 120, and 180 min from the same data set were compared with the results of standard LHBT.

Results: Sixty IBS-D patients and 60 HVs were studied. The genotype in all participants was C/C-13910. LM and LI detection rates increased with lactose dose from 10 g, 20 g to 40 g in both groups (P < 0.001). 4SLHBT showed excellent diagnostic concordance with standard LHBT (97%-100%, Kappa​​ 0.815-0.942) with high sensitivity (90%-100%) and specificity (100%) at all three lactose doses in both groups.

Conclusion: Reducing the number of measurements from 13 to 4 samples did not significantly impact on the accuracy of LHBT in health and IBS-D. 4SLHBT is a valid test for assessment of LM and LI in clinical practice.

Trial registration: ClinicalTrials.gov NCT01286597.

Keywords: Diagnosis; Irritable bowel syndrome; Lactose hydrogen breath test; Lactose intolerance; Lactose malabsorption.

Figures

Figure 1

Lactose malabsorption and lactose intolerance detection rates over time in irritable bowel syndrome patients with diarrhea group (A) and healthy volunteer group (B). The detection rates of LM and LI increased over time and reached a peak at 150-180 min interval. LM: Lactose malabsorption; LI: Lactose intolerance; IBS-D: Irritable bowel syndrome patients with diarrhea.