Microbiome-mediated Biotransformation of Human Lactoferrin (effera(R)) Enhances Epithelial Barrier Function in an Ex Vivo Adult Model

Lactoferrin is a multifunctional iron-binding glycoprotein that supports intestinal barrier function, immune regulation, and a favorable gut microbial environment. However, the contribution of gut microbial biotransformation to its gastrointestinal activity remains poorly understood. We investigated whether effera(R), a precision fermentation-derived recombinant human lactoferrin, supports intestinal barrier function through microbiome-mediated mechanisms. effera(R) underwent simulated upper gastrointestinal digestion followed by ex vivo colonic fermentation using the validated SIFR(R) technology pipeline, which employs bioreactors that are inoculated with fecal microbiota from six healthy adult donors. Microbial activity was evaluated by measuring short-chain fatty acid (SCFA) production, bacterial cell density, and microbiome composition. effera(R) produced dose-dependent increases in the production of SCFAs and bacterial cell density demonstrating enhanced microbial metabolic activity. These metabolic changes were accompanied by shifts in key microbial groups within Bacillota_A and Bacteroidota. Intact effera(R) and cell-free post-colonic fermentation-derived products were evaluated in a Caco-2/THP-1 epithelial-immune co-culture model under basal and lipopolysaccharide-challenged conditions. Whereas intact protein did not significantly improve epithelial barrier integrity, effera(R)s post-colonic fermentation-derived products significantly enhanced transepithelial electrical resistance (TEER) under basal conditions and produced an even stronger barrier-protective response following LPS challenge. Across matched doses, effera(R) consistently generated greater TEER responses than bovine lactoferrin. Improved barrier function was accompanied by increased expression of tight-junction-associated targets ZO-1 and occludin and reduced secretion of CXCL-10 and IL-8. Together, these findings demonstrate that microbial biotransformation enhances the biological activity of effera(R), linking increased microbial metabolism with improved epithelial barrier integrity and modulation of inflammatory signaling. This integrated study provides a strong mechanistic foundation for the use of human lactoferrin in adult gut-health applications and offers valuable guidance for future adult clinical studies and infant-relevant investigations.