Microbial Fermentation of Gardenia Jasminoides: Biotransformation Mechanisms and Development of Value-Added Functional Products

Abstract

Gardenia jasminoides has long been recognized as a medicinal and functional plant rich in iridoid glycosides and bioactive compounds, among which geniposide represents the predominant constituent. However, the biological efficacy of native Gardenia phytochemicals is often limited by their glycosylated structure and low bioavailability. Microbial fermentation has emerged as an effective biotechnological strategy to enhance the functional value of Gardenia jasminoides through enzymatic biotransformation. During fermentation, diverse microorganisms including lactic acid bacteria, filamentous fungi, and symbiotic microbial consortia catalyze the conversion of geniposide into genipin and other secondary metabolites primarily via β-glucosidase activity. This transformation significantly improves biological activities, including anti-inflammatory, antioxidant, antimicrobial, and metabolic regulatory effects. Recent studies demonstrate that probiotic strains such as Levilactobacillus and Lactiplantibacillus plantarum enhance anti-inflammatory responses by suppressing nitric oxide and cytokine production, while fungal fermentation by Aspergillus niger generates novel antibacterial derivatives with increased bioactivity. In addition, fermentation systems applied in functional foods, including kombucha beverages and fermented dairy products, further promote the formation of health-promoting metabolites and improve physiological outcomes such as glycemic regulation. Collectively, microbial fermentation transforms Gardenia jasminoides from a traditional herbal resource into a versatile platform for developing value-added functional foods, natural bioactive compounds, and nutraceutical applications. Future research integrating microbial genomics and controlled fermentation design will further expand its industrial and biomedical potential.