Faecal intestinal permeability and intestinal inflammatory markers in older adults with age-related disorders: A systematic review and meta-analysis
Nurul Izzati Ahmad Fadzuli, Siong Meng Lim, Chin Fen Neoh, Abu Bakar Abdul Majeed, Maw Pin Tan, Hui Min Khor, Ai Huey Tan, Kalavathy Ramasamy
Abstract
This systematic review and meta-analysis appraised previous findings to uncover potential faecal intestinal permeability and intestinal inflammatory markers in older adults. A comprehensive literature search led to the identification of ten eligible studies with findings of potential faecal intestinal permeability (zonulin and alpha-1-antitrypsin) and intestinal inflammatory markers [calprotectin, lactoferrin and neutrophil gelatinase-associated lipocalin (NGAL)]. Most of the cases (n > 2) [Parkinson’s disease (PD) and Alzheimer’s disease (AD)] exhibited higher faecal alpha-1-antitrypsin, zonulin and calprotectin levels. The present meta-analysis confirmed significantly higher faecal alpha-1-antitrypsin in older persons with PD compared to non-PD [MD = 22.92 mg/dL; 95 % CI = 14.02–31.81, p < 0.00001; I 2 = 0 % ( p = 0.73)]. There was, however, no significant difference in faecal zonulin between PD and non-PD individuals [MD = 26.88 ng/mL; 95 % CI = −29.26–83.01, p = 0.35; I 2 = 94 % ( p < 0.0001)]. Meanwhile, faecal calprotectin was higher in older adults with GI symptoms , multiple system atrophy (MSA) or PD than the healthy controls [MD = 9.51 μg/g; 95 % CI = 0.07–18.95, p = 0.05; I 2 = 84 % ( p < 0.00001)]. Altogether, faecal calprotectin appears to be a potential intestinal inflammatory marker whereas previous findings on faecal alpha-1-antitrypsin as an intestinal permeability marker remain limited and require further validation.