Is Carbohydrate Intolerance associated with carbohydrate malabsorption in Disorders of Gut-Brain Interaction (DGBI)? 2025 Mikhael-Moussa et al

Abstract

Introduction:
We aimed to explore the prevalence of carbohydrate (lactose and fructose) intolerance in patients with disorders of gut-brain interaction (DGBI), and to characterize those patients in terms of gastrointestinal and non-gastrointestinal symptoms.

Methods:
DGBI patients who were referred to the Physiology Unit of our Hospital between May 2022 and December 2023 for lactose (25g) and fructose (25g) breath tests were prospectively included. Patients were required to have a negative glucose breath test, prior to lactose and fructose breath tests, and to have completed the adult carbohydrate perception questionnaire (aCPQ) during each breath test. Intolerance was defined as an increase of ≥20 mm in the visual analog scale (VAS) score from baseline in at least one of the 5 symptoms (pain, nausea, bloating, flatulence, diarrhea) assessed with the aCPQ.

Results:
Among the 301 DGBI patients included in our analysis, 178 (59.1%) had carbohydrate intolerance. Carbohydrate-intolerant patients were significantly more likely to be female (p-value < 0.001), to have 2 or more DGBI (p-value= 0.001), to have lactose maldigestion (p-value< 0.001) and fructose malabsorption (p-value= 0.023), higher IBS and somatic symptom severity, and lower quality of life (p-value < 0.001) compared to patients without carbohydrate intolerance. The binary logistic regression showed that lactose maldigestion (p-value= 0.001), as well as somatic symptoms (p-value= 0.025), were independently associated with carbohydrate intolerance (Nagelkerke R Square= 0.206).

Discussion:
Carbohydrate intolerance affects a substantial group of DGBI patients, impacting their quality of life and symptom severity. Further research is needed to explore the underlying mechanisms in patients who do not have carbohydrate malabsorption/maldigestion.

Paywall

 

This sounds more like they had a disorder of the gut than of the brain.

 

I think gut research is still in the very early stages. It's not as simple as studying one single aspect, such as maldigestion of a single sugar. Having an excess of that sugar alters the microbial strain ratios, which alters the metabolite levels, which alters the brain, which alters the gut functions, which alters other microbial strain ratios, which alters ... Research such as this is a starting point, rather than something to make major medical decisions about.