Fig. 1. The schematic flowchart describing the procedure of the clinical research.

V1–8, the subjects attended the visit following overnight fasting (at least 8 h) for data collection and commencement of the next steps. C1 and 2, phone check to determine the subjects’ compliance with the diet and assess any adverse events. GC gluten challenge, GC with E gluten challenge with the enzyme mixture, GC with P gluten challenge with placebo