Randomized Control Trial of L-Alanine and Placebo in Fructose Intolerance
Investigation of Supplemental L-alanine in the Management of Dietary Fructose Intolerance: a Double-blind, Randomized Crossover Study
Data suggest that alanine may facilitate the intestinal absorption of fructose in patients
with DFI and thereby may decrease GI symptoms.
We hypothesize that the ingestion of supplemental L-alanine along with mixed meals or snacks
that contain foods with free fructose or high fructose content will decrease GI symptoms in
subjects with dietary fructose intolerance by facilitating intestinal absorption of fructose.
Aim: To investigate the effects of co- administration of equi-molar doses of L-alanine or
placebo on the occurrence of GI symptoms in subjects with dietary fructose intolerance, in a
randomized, double blind, cross over study.
Methods: We propose to investigate the effects of co-administration of equi-molar doses of
L-alanine or placebo on the occurrence of GI symptoms in 70 subjects with dietary fructose
intolerance, in a randomized, double blind, cross over study.
Data Analysis: The primary outcome measure will be a comparison of baseline breath sample
values and study visit breath sample values. Additionally, we will assess subject-reported
occurence and severity of nine gastrointestinal symptoms during the test on a visual analog
Expected Results: We anticipate that dietary fructose intolerance (DFI) symptoms will improve
with ingestion of supplemental L-alanine (along with foods containing free fructose or high
fructose content). We additionally expect treatment of DFI with administration of L-alanine
powder to be more practical than co-ingestion of alanine-rich foods, and more convenient for
GI symptom score
Dietary Fructose Intolerance
Study Arms / Comparison Groups
Description: Subjects will consume l-alanine prior to eating fructose-containing foods.
* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.
Primary Completion Date
1. Age between 18-99 years
2. Diagnosis of fructose malabsorption (positive breath test after ingestion of 25 grams
of fructose defined as either (a) ≥ 20 ppm rise of breath H2/CH4/both over baseline
values or a successive rise of ≥ 5 ppm over baseline and in 3 consecutive breath
1. Cognitive impairment or any other inability to provide informed consent
3. GI surgery except appendectomy, cholecystectomy, caesarean section, hysterectomy
4. Antibiotics in the previous 6 weeks
5. History of bacterial overgrowth or lactose intolerance
6. Major co-morbid illnesses, including chronic pancreatitis, celiac disease,
inflammatory bowel disease, diabetes, scleroderma, pseudo-obstruction syndromes etc.
7. Known food allergies
8. Medication use: opioids, Tegaserod, laxatives, enemas
9. An allergy or intolerance to any fiber supplements or other dietary nutritional
supplements such as: psyllium (Metamucil), Maltodextrin, Citric Acid, and
10. Difficulty swallowing