Oral Presentation Joint Annual Scientific Meeting of the Nutrition Society of NZ and the Nutrition Society of Australia

Adding glucose to fructose reduces breath hydrogen but not symptoms in fructose malabsorbers with a functional bowel disorder (246)

Caroline Tuck 1 , Lauren Ross 1 , Peter Gibson 1 , Jacqueline Barrett 1 , Jane Muir 1
  1. Department of Gastroenterology, Monash University, Melbourne, Victoria, Australia

Background/Aims: Fructose absorption is enhanced by the addition of equal amounts of glucose in healthy volunteers. The success of this strategy in reducing abdominal symptoms when consuming free fructose or fructans in functional bowel disorders (FGID) is unknown. This randomised, double-blind, cross-over trial aimed to address these issues.

Methods: Breath hydrogen and symptom response to sugar solutions- glucose; sucrose; fructose; fructose+glucose; fructo-oligosaccharide (FOS); FOS+glucose – were assessed in patients with fructose malabsorption and a FGID. Following a 24h run-in period where participants consumed a diet low in fermentable carbohydrates (fibre and FODMAPs), participants collected breath samples at baseline and every 20min for 4h after consuming the sugar solution. Breath hydrogen was calculated as area-under-the-curve. Symptom scores were recorded at the end of each day, using a 100mm visual analogue scale.

Results: In 26 participants (3 male, aged 22-65y), breath hydrogen response to 25g fructose (775±904ppm.4h (mean±SD)) reduced following the addition of 25g glucose (84±99;p=0.012, t-test), which was similar to that after glucose alone (133±175). Breath hydrogen response to 10g FOS (3089±1688) was unchanged with glucose addition (2166±1320;p=0.559). Overall abdominal symptoms after fructose (median 15mm, IQR 2-46) or FOS (19,2-32) were not changed with glucose addition (5,1-35;p=0.236; 17,2-46,p=0.926, respectively).  Glucose addition worsened abdominal pain with FOS (5,1-16vs13,2-18;p=0.049) and nausea with fructose (1,0-2vs2,1-10; p=0.018).

Conclusions: These results do not support the addition of glucose to free fructose or fructans as it does not reduce, and potentially worsens symptoms associated with consumption of these sugars in patients with FGID.

Funding source: None.