Evaluation of adherence to Gluten-free Diet

The only treatment for celiac patients is to follow a lifetime gluten-free diet (GFD) in order to recover from the damage of their intestinal villi and avoid other complications associated with Celiac Disease.

Usually, the follow-up on GFD is carried out using dietary questionnaires, the analysis of the serological markers or the intestinal biopsy. However, the former are not completely reliable, due to the possibility of overlooking an inadvertent trangression or the patient being not totally sincere when filling in the questionnaire.

On the other hand, in the case of serological markers, it is usual that significant differences are only seen when there is repeated non-compliance with GFD. Regarding the performance of intestinal biopsies, it is a highly reliable method, but very invasive. In fact, ESPGHAN advises against periodic biopsy in children due to the negative impact on their quality of life.

Use of non-invasive markers to monitor Gluten Free Diet

The detection of Gluten Immunogenic Peptides (GIP) in human samples (feces and urine) has been postulated as a reliable and efficient method to monitor GDF. GIP are gluten fragments resistant to gastrointestinal digestion and are excreted through urine and feces.

In the study by Roca et al. (2021), the usefulness and efficacy of the detection of GIP in faeces to control adherence to GFD in celiac children was proven. While the dietary questionnaire only found transgressions in 9% of the children; GIP was detected in 35% of these pediatric patients. These results support the convenience of using GIP detection methods to control compliance with the GFD, both at the clinical level and by the patient.

In conclusion, it is confirmed that the detection of GIP in feces and urine is a more effective method in the identification of trangression in GFD than the dietary questionnaires.

Fig. 1 Percentage of transgressions detected in the study by Roca et al. (2021) using different methods.


Roca, M., Donat, E., Masip, E. et al. Analysis of gluten immunogenic peptides in feces to assess adherence to the gluten-free diet in pediatric celiac patients. Eur J Nutr 60, 2131–2140 (2021). https://doi.org/10.1007/s00394