Determination of gluten consumption in celiac disease patients on a gluten-free diet

Am J Clin Nutr. 2018 Feb 1;107(2):201-207. doi: 10.1093/ajcn/nqx049.


Background: Celiac disease (CD) patients adhering to a gluten-free diet (GFD) are exposed frequently to low levels of gluten that contribute to symptoms and persistent intestinal histologic damage.

Objective: We analyzed prior clinical data to determine how much gluten is accidentally consumed while on a GFD. The aim was to understand the range of gluten consumption for a wide distribution of CD patients.

Design: A meta-analysis was conducted on data from 2 different clinical programs: 1) measurements of gluten in stool and urine in CD and non-CD populations; and 2) analysis of data from trials for the investigational therapeutic latiglutenase. The stool and urine studies included controlled gluten challenges. A calibration factor was applied that allowed normal ingestion of gluten to be computed from the urine and stool measurements. From the latiglutenase trial data, a determination of gluten consumption was made by estimating how much gluten was eliminated from patients' diets due to a trial effect that led to improved histology even in the placebo group.

Results: The average inadvertent exposure to gluten by CD individuals on a GFD was estimated to be ∼150-400 (mean) and ∼100-150 (median) mg/d using the stool test and ∼300-400 (mean) and ∼150 (median) mg/d using the urine test. The analyses of the latiglutenase data for CD individuals with moderate to severe symptoms indicate that patients ingested significantly >200 mg/d of gluten.

Conclusions: These surrogate biomarkers of gluten ingestion indicate that many individuals following a GFD regularly consume sufficient gluten to trigger symptoms and perpetuate intestinal histologic damage.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers / blood
  • Biomarkers / urine
  • Celiac Disease / diet therapy*
  • Diet, Gluten-Free*
  • Feces / chemistry
  • Glutens / administration & dosage
  • Glutens / urine*
  • Humans
  • Observational Studies as Topic
  • Peptide Hydrolases / therapeutic use
  • Randomized Controlled Trials as Topic


  • Biomarkers
  • Glutens
  • ALV003
  • Peptide Hydrolases