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Investigation of Alanine in Fructose Intolerance: A Dose Ranging Study

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified March 2011 by University of Iowa.
Recruitment status was:  Recruiting
Teikyo University
Information provided by:
University of Iowa Identifier:
First received: September 22, 2009
Last updated: March 7, 2011
Last verified: March 2011


Over the past few decades, fructose is increasingly being used as a sweetener/ additive in a variety of foods. Incomplete absorption of fructose has been implicated as a cause of gastrointestinal symptoms. In tertiary care centers, the prevalence of fructose malabsorption in subjects with unexplained GI symptoms is thought to be between 11-50%, when assessed with breath tests following administration of 25 grams of fructose in a 10% solution. Restriction of dietary fructose has been shown to improve symptoms in these patients to an extent. Currently, there are no therapeutic agents that improve intestinal fructose absorption and thereby decrease symptoms. Studies in the pediatric population have shown that fructose absorption in the small intestine is increased in the presence of glucose or amino acids, especially alanine.


The investigators' objective is to assess whether co-administration of an oral solution of L-alanine facilitates fructose absorption and decreases gastrointestinal (GI) symptoms associated with fructose malabsorption in subjects undergoing standard fructose breath test when compared to placebo.

Methods and analysis:

The investigators propose a randomized, double-blind study in 40 subjects with known fructose intolerance. After an overnight fast, each subject will receive an oral solution of 12.5 grams of alanine in 125cc of water or placebo. Next, the subject will receive an oral solution of 25 grams of fructose in a 10% solution. Serum, urine and breath samples will be collected at baseline and at 30-minute intervals for 4 hours. GI symptoms will also be assessed and recorded at 30 minute intervals using a standard questionnaire. Repeated measures ANOVA will be used to compare the data obtained during the study protocol with the baseline (pre-study) data.

Expected outcomes:

Co-administration of alanine with fructose may improve fructose absorption and decrease symptoms in subjects with fructose intolerance.

Hypothesis: Ingestion of alanine along with fructose, will facilitate intestinal absorption of fructose in subjects with fructose malabsorption.

Aim: To investigate the effects of co-administration of equi-molar doses of alanine on a) the absorption of fructose and b) the occurrence of GI symptoms in subjects with fructose malabsorption.

Condition Intervention Phase
Fructose Intolerance
Dietary Supplement: Placebo
Dietary Supplement: Alanine
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Treatment
Official Title: Investigation of Alanine in Fructose Intolerance: A Randomized, Double Blind, Dose Ranging, Placebo Controlled Study

Resource links provided by NLM:

Further study details as provided by University of Iowa:

Primary Outcome Measures:
  • Decrease breath Hydrogen and/or Methane production [ Time Frame: less than 6 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Occurrence or severity of GI symptoms during the test [ Time Frame: less than 6 months ] [ Designated as safety issue: No ]

Estimated Enrollment: 40
Study Start Date: September 2007
Estimated Study Completion Date: December 2010
Estimated Primary Completion Date: December 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Placebo
Subjects will receive placebo (mix of sugar and salt).
Dietary Supplement: Placebo
Subjects will receive placebo (mix of sugar and salt) 20 minutes before consuming fructose.
Experimental: Alanine - 12.5
Subjects will receive 12.5 grams of alanine
Dietary Supplement: Alanine
Subjects will receive 12.5 grams of alanine 20 minutes before consuming fructose.
Experimental: Alanine - 25
Subjects will receive 25 grams of alanine.
Dietary Supplement: Alanine
Subjects will receive 25 grams of alanine 20 minutes before consuming fructose.


Ages Eligible for Study:   18 Years to 70 Years   (Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Age between 18-70 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 3 months
  5. 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. Diabetes
  Contacts and Locations
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Please refer to this study by its identifier: NCT01185210

United States, Iowa
University of Iowa Hospitals and Clinics
Iowa City, Iowa, United States, 52242
Sponsors and Collaborators
University of Iowa
Teikyo University
Principal Investigator: Satish Rao, Md, PhD University of Iowa
  More Information

Responsible Party: Satish SC Rao/Professor of Medicine and Director of Neurogastroenterology and GI Motility, University of Iowa Identifier: NCT01185210     History of Changes
Other Study ID Numbers: Fructose: Double Blind 
Study First Received: September 22, 2009
Last Updated: March 7, 2011
Health Authority: United States: Institutional Review Board

Additional relevant MeSH terms:
Fructose Intolerance
Fructose Metabolism, Inborn Errors
Carbohydrate Metabolism, Inborn Errors
Metabolism, Inborn Errors
Genetic Diseases, Inborn
Metabolic Diseases processed this record on December 08, 2016