Background: There is no evidence that a positive breath test is a good predictor of success of a carbohydrate-restricted diet.
Objective: To investigate whether patients in whom lactose or fructose intolerance (LIT, FIT) is diagnosed by symptom measurement using the adult Carbohydrate Perception Questionnaire (aCPQ) respond to diet.
Methods: Consecutive patients referred for evaluation of lactose or fructose intolerance underwent hydrogen/methane breath testing (malabsorption test) and symptom measurement with aCPQ (intolerance test) before and after 50g lactose or 25g fructose. Patients with a positive aCPQ received instructions on specific diets and supplements. Severity of abdominal pain, bloating, diarrhoea, flatulence and nausea were measured using a visual analogue scale (VAS) before (VAS1,mm) and after diet (VAS2,mm). The change in VAS for individual symptoms and overall symptoms after diet is expressed as deltaVAS (mm) and as change relative to VAS1 (%).
Results: Forty-one patients were included (23 LIT, 8 FIT, 10 LIT+FIT). Eight patients had negative breath tests (no malabsorption). After two-months of diet, the overall VAS and the individual symptoms decreased (p<0.001). Overall VAS1 and the VAS1 for individual symptoms correlated significantly with the decrease in deltaVAS (mm) after diet. Nineteen patients (46%) had total recovery and additional 13 patients (32%) had improvement of >50%. Response to diet was independent of breath test results.
Conclusion: This uncontrolled and unblinded study suggests that patients with carbohydrate intolerance diagnosed by aCPQ benefit significantly from diet, independent of the presence of malabsorption. Controlled studies are required to confirm these results in larger patient groups.
The Author(s). Published by S. Karger AG, Basel.