Fermented soy protein Maillard reaction products attenuate Gardnerella vaginalis-induced vaginal and intestinal inflammation: involvement of TLR2/NF-κB suppression and short-chain fatty acid restoration

This study investigated the ameliorative effects of Maillard reaction product (MRP) and its Lacticaseibacillus rhamnosus IM18-fermented derivative (MRPF) against Gardnerella vaginalis -induced inflammation. In G. vaginalis -stimulated VK2/E6E7 cells, both MRP and MRPF suppressed NF-κB activation and pro-inflammatory gene expression. In a G. vaginalis -induced mouse model, both materials reduced G. vaginalis colonization, alleviated vaginal histopathology, and suppressed pro-inflammatory mediator expression across vaginal, cervical, and colonic tissues. MRPF suppressed upstream TLR2/TRAF6 and downstream NF-κB signaling in both tissues, while MRP predominantly attenuated downstream signaling. MRPF further demonstrated superior restoration of intestinal tight junction proteins and modulated gut microbiota composition, accompanied by recovery of fecal short-chain fatty acid profiles. These findings suggest that MRP and MRPF, particularly MRPF, exert anti-inflammatory effects accompanied by modulation of TLR2/NF-κB signaling, restoration of intestinal barrier function, and recovery of short-chain fatty acid production, supporting their potential as functional food-derived candidates for dietary management of vaginal and intestinal inflammation.