Food-Derived Bioactives and the Endothelial Glycocalyx: Chemical Determinants, Molecular Mechanisms, and Translational Evidence

Food-derived bioactives can modify the endothelial glycocalyx, but chemical identity, achievable exposure and the meaning of the measured response must be considered together. This narrative review integrates evidence identified through PubMed, Scopus and Web of Science to examine those connections. Experimental studies show reduced loss of surface glycans, altered glycosaminoglycan turnover and changes in layer hydration; selected studies also demonstrate improved permeability or flow-related signaling. These findings support glycocalyx modulation as a biological effect, while distinguishing preservation, swelling and post-injury recovery. Quantitative comparisons reveal substantial gaps between some active culture concentrations and human plasma exposure, compounded by conjugation and uncertain absorption of intact polysaccharides. Surface staining, circulating syndecan-1 and the perfused boundary region measure different processes and cannot individually establish complete restoration. Human trials show favorable surrogate outcomes for some preparations and neutral results for others; multicomponent products and small samples limit ingredient attribution, and responsive patient groups remain unestablished. The contribution of this review is to connect chemical and exposure evidence with what each endothelial endpoint can substantiate. Together, the studies support specific mechanisms of surface-layer modulation but do not yet establish sustained vascular benefit from oral glycocalyx-directed nutrition.