Examining intraindividual variability of urinary gluten immunogenic peptides compared to the lactulose-mannitol ratio in healthy volunteers: implications for clinical assessment of intestinal permeability

u-GIP demonstrated lower intraindividual variability and higher consistency than LMR, indicating its potential as a robust and reliable marker for assessing intestinal permeability. Unlike LMR, GIP showed better reproducibility across days and minimal influence from dietary fluctuations. Its advantages include direct clinical relevance as an immunogenic dietary protein marker, reduced physiological variability and non-invasive methods. These features highlight u-GIP promising potential for future clinical and research applications. However, further studies are needed to validate its effectiveness specifically in patients with altered intestinal permeability.