Mixed-Culture Fermentation of Coffee Pulp Induces Metabolomic Changes and Enhances Multi-Target Bioactivity Relevant...

Androgenetic alopecia (AGA), the most common form of hair loss, is driven by dihydrotestosterone-mediated follicular miniaturization, oxidative stress, and perifollicular inflammation, requiring multi-target intervention. Coffee pulp is an abundant coffee-processing by-product and a potential source of value-added bioactives relevant to AGA. This study investigated whether fermentation with Saccharomyces cerevisiae, Lactobacillus plantarum, or their mixed culture could remodel coffee pulp composition and enhance biological activities relevant to AGA. Untargeted metabolomics revealed treatment-dependent metabolic remodeling. LP-CP showed the largest number of significantly altered metabolite features (1020; 666 increased and 354 decreased), whereas MIX-CP exhibited a predominantly upward pattern, with 238 of 283 significantly altered features (84.10%) showing increased abundance relative to the unfermented control. Targeted polyphenol analysis showed MIX-CP contained the highest levels of rosmarinic acid and quercetin. In human hair follicle dermal papilla cells, MIX-CP stimulated proliferation, increased fibroblast proliferation in a conditioned-medium model, partially rescued cell viability under potassium-channel inhibition, and attenuated intracellular reactive oxygen species and lipid peroxidation more than monoculture-fermented extracts. At the transcriptional level, MIX-CP downregulated androgen metabolism genes SRD5A1 and SRD5A2 alongside pro-regression mediator TGFB1 while upregulating Wnt/β-catenin (CTNNB1), Sonic Hedgehog (SHH, SMO, GLI1), and angiogenic (VEGF) genes, showing transcript-level modulation comparable to standard hair-loss drugs for most targets. These findings position MIX-CP as a promising multi-target cosmeceutical for AGA management, warranting further in vivo validation.