Introduction
Patients with Disorders of Gut-Brain Interaction (DGBI) often experience meal-related symptoms, potentially due to carbohydrate intolerances like fructose and/or lactose. While breath tests are common for exploring carbohydrate malabsorption, assessing intolerances, defined by the onset of gastrointestinal (GI) symptoms after a defined load of carbohydrates, is valuable. The adult carbohydrate perception questionnaire (aCPQ) can be used for detecting carbohydrate intolerances (1).
Aims & Methods
We aimed to determine lactose and fructose intolerance prevalence in DGBI and characterize these patients. DGBI patients who underwent fructose (25g) and lactose (25g) breath tests alongside the aCPQ in our tertiary center between May 2022 and December 2023 were included. Carbohydrate intolerance was a 20 mm increase in any of the five Visual Analog Scales (VAS) scores (for abdominal pain, nausea, diarrhea, bloating, and flatulence) in aCPQ. An increase from baseline of ≥20 ppm in exhaled H2 or ≥10 ppm of CH4 (≥20 ppm for fructose) indicated malabsorption. Patients completed questionnaires on irritable bowel syndrome (IBS) symptom severity (IBS-SSS), somatic symptoms (PHQ-15), quality of life (QOL)(GIQLI), anxiety, and depression (HAD).
Results
We included 314 DGBI patients, among them, 124 were lactose intolerant, 138 were fructose intolerant, and 77 were intolerant to both carbohydrates. Lactose intolerant patients were younger (42± 15.9 vs 46 ± 15.3; p=0.022), and more likely to have lactose malabsorption and fructose intolerance, while fructose intolerant patients were more likely to have fructose malabsorption, lactose intolerance, and higher anxiety/depression levels. Both intolerant groups were more likely to be female (81.5% vs 61.6%; p<0.0001 for lactose, 77.5% vs 63.1%; p=0.006 for fructose), with 2 DGBI or more (63.1% vs 40.7%; p<0.0001 for lactose, 57.4% vs 43.5%; p=0.021 for fructose), to have a reduced QOL, higher levels of GI symptoms, and somatic symptoms (table). Logistic regressions showed independent associations of female sex, fructose intolerance, and lactose malabsorption with the lactose intolerance variable, and IBS symptom severity, lactose intolerance, and fructose malabsorption with the fructose intolerance variable.
Table: Comparison of DGBI patients with and without lactose and fructose intolerance
| Variable | Positive Lactose Intolerance (n=124) | Negative Lactose Intolerance (n=190) | P-value | Positive Fructose Intolerance (n=138) | Negative Fructose Intolerance (n=176) | P-value |
| Positive Lactose Malabsorption | 49 (39.5) | 29 (15.3) | <0.0001 | 38 (27.5) | 40 (22.7) | 0.328 |
| Positive Fructose Malabsorption | 36 (29) | 45 (23.7) | 0.290 | 49 (35.5) | 32 (18.1) | <0.0001 |
| Positive Fructose Intolerance | 77 (62.1) | 61 (32) | <0.0001 | | | |
| Positive lactose intolerance |
|
| | 77 (55.8) | 47 (26.7) | <0.0001 |
| GIQLI | 86 ± 20.85 | 95 ± 19.49 | <0.0001 | 85.1 ± 19.96 | 96.4 ±19.45 | <0.0001 |
| IBS-SSS | 252 ± 100.87 | 207 ± 101.53 | <0.0001 | 255.6 ± 98.48 | 201.2 ± 101.06 | <0.0001 |
| HAD-Anxiety | 7.9 ± 4.11 | 7.8 ± 4.03 | 0.970 | 8.4 ± 3.97 | 7.4 ± 4.08 | 0.032 |
| HAD-Depression | 5.7 ± 3.8 | 5.2 ± 3.6 | 0.233 | 6 ± 3.74 | 4.9 ± 3.63 | 0.012 |
| PHQ-15 | 13 ± 5.51 | 10 ± 4.97 | 0.0001 | 13 ± 5.34 | 10 ± 4.98 | <0.0001 |
Values are n (%), or mean ± SD.
GIQLI, Gastrointestinal Quality of Life Index; IBS-SSS, irritable bowel syndrome symptom severity score; HADS, Hospital Anxiety and Depression Scale; PHQ-15, patient health questionnaire 15. Conclusion
DGBI patients with lactose and fructose intolerance exhibit severe IBS symptoms and reduced QOL. Interestingly, intolerance to one carbohydrate is associated with malabsorption of this specific carbohydrate and the coexistence of intolerance to the other carbohydrate.
References
1. Hammer, Johann et al. European journal of gastroenterology & hepatology 2021, doi:10.1097/MEG.0000000000001880
Disclosure
CM has served as a consultant/advisory board member for KyowaKirin, Norgine, Biocodex, Mayoly Spindler, Tillots, Ipsen, Nestlé HealthScience and Viatris.
FM has served as a consultant/speaker for Laborie, Medtronic, Dr Falk Pharma.
GG has served as a consultant/speaker for Laborie, Medtronic, Kyowa Kirin, Lilly and Enterra medical.