Hyaluronic acid (HA) is a ubiquitous polysaccharide with diverse biological functions. Is known that in the intestinal epithelium, the exogenous HA of molar mass >= 10(5) Da orally administered antagonizes TLR4 over-expression resulting from dysbiosis and promotes immunomodulation in multifactorial crosstalk, thus helping to treat or to prevent injuries. As macromolecules mediate cell signaling, the three-dimensional structure of HA plays a vital role in those functions. Introducing HA in terms of its molecular structure, its spatial architecture as dependent on pH, concentration and molar mass, occurrence, biological functions and turnover in the tissues, this review addresses the HA in the gastrointestinal system, the molecular dynamics of intestinal uptake and signaling, immunomodulation at intestinal and systemic levels and HA fate to other tissues. Finally, at the light of these behaviors, a nanotechnological approach is presented as progress in the field of the oral HA administration and discussed with perspectives for future developments Ver menos