Effects of dietary education, followed by a tailored fructose-restricted diet in adults with fructose malabsorption.
OBJECTIVE
Fructose is absorbed by GLUT transporters in the small intestine. If this process is inadequate, abdominal symptoms because of fructose intolerance may arise. The effect of a tailored fructose-restricted diet on gastrointestinal complaints was assessed in patients with fructose intolerance.


METHODS
Following an abnormal fructose breath test (50 g), 107 patients (64 also with lactose intolerance) entered three study periods: weeks 0-32 (free diet), weeks 32-36 (progressive increasing amount of fructose up to quantity inducing symptoms, 'trigger dose'), and weeks 36-48 (tailored fructose-restricted diet according to the 'trigger dose'). A subgroup of 15 patients underwent additional fructose breath tests (35, 25 g) to compare three different doses.


RESULTS
At baseline, the most frequent symptoms were bloating and abdominal pain, and were more severe with combined fructose and lactose intolerance. During the free diet, patients reported eliminating (48%) or reducing (52%) fructose-containing foods, with a significant improvement in symptoms (abdominal pain from 79.7 ± 1.3 to 19.3 ± 1.8 mm; bloating from 83.1 ± 1.3 to 19.4 ± 1.8 mm; number of evacuations/day from 3.9 ± 0.16 to 1.1 ± 0.04; Bristol score from 5.1 ± 0.14 to 3.8 ± 0.1, P < 0.00001). During the tailored fructose-restricted diet, the consistent improvement in symptoms persisted and was similar to the improvement on free diet (abdominal pain 23.6 ± 1.9 mm; bloating 19.4 ± 1.8 mm; number of evacuations/day 1.7 ± 0.07; Bristol score 3.5 ± 0.06, P<0.00001 vs. baseline). A dose-dependent effect of fructose was observed on symptoms during the fructose breath test.


CONCLUSIONS
In our setting, individuals with fructose intolerance show an inappropriate dietary self-management. By contrast, a tailored fructose-restricted diet improves gastrointestinal symptoms without senseless food deprivation.
aDepartment of Biomedical Sciences and Human Oncology, Clinica Medica "A. Murri", Policlinico Hospital, University of Bari Medical School, Bari, Italy bDepartment of Medicine II, Saarland University Medical Center, Homburg, Germany cLaboratory of Metabolic Liver Diseases, Department of General, Transplant, and Liver Surgery, Medical University of Warsaw, Warsaw, Poland dDepartment of Medicine, Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA eItalian College of General Practitioners, Florence, Italy.
Leonilde
L
Bonfrate
Marcin
M
Krawczyk
Antony
A
Lembo
Ignazio
I
Grattagliano
Frank
F
Lammert
Piero
P
Portincasa
D015746:Abdominal Pain / Q000209:etiology; D000328:Adult; D001944:Breath Tests / Q000379:methods; D015331:Cohort Studies; D005260:Female; D005414:Flatulence / Q000209:etiology; D005500:Follow-Up Studies; D005632:Fructose / Q000008:administration & dosage* / Q000378:metabolism; D005633:Fructose Intolerance / Q000150:complications / Q000175:diagnosis* / Q000178:diet therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012648:Self Care; D012680:Sensitivity and Specificity
D005632:Fructose