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 scale (VAS).

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 patients.

Inclusion Criteria:

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 samples)

Exclusion Criteria:

1. Cognitive impairment or any other inability to provide informed consent
2. Prisoners
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 methylcellulose (Citrucel).
10. Difficulty swallowing