Harnessing probiotic fermentation to enhance the bioavailability and health impact of dietary phytochemicals

Probiotic fermentation has emerged as a promising strategy to enhance the bioavailability of dietary phytochemicals, thereby amplifying their antioxidant, anti-inflammatory, and disease-preventive properties. This review explores the strain-specific roles of Lactobacillus and Bifidobacterium in modulating phytochemical absorption through enzymatic biotransformation and microbial metabolism. Evidence suggests that probiotic fermentation can improve polyphenol bioavailability by 30–50 % in both dairy and plant-based food matrices. In particular, L. plantarum , L. rhamnosus , and B. longum have shown the most consistent ability to transform polyphenols, flavonoids, and plant polysaccharides into more bioavailable forms. This review compares dairy and non-dairy fermented foods in improving phytochemical function and managing metabolic, cardiovascular, and diabetic conditions. Fermentation primarily enhances antioxidant activity, anti-inflammatory metabolites such as short-chain fatty acids, and the extraction efficiency of polysaccharides, thereby broadening the spectrum of bioactivities. Additionally, it discusses the impact of fermentation on the role of the food matrix in influencing fermentation efficiency and the combined effects of probiotics with fermented foods, which contribute synergistically to health outcomes. Despite rising commercial interest in probiotic-fermented foods, barriers remain in consumer acceptance, cost, and regulation. Overall, this review highlights the unique contribution of microbial fermentation integrating strain-specific mechanisms, phytochemical diversity, and food matrix effects as a natural, consumer-friendly approach to improve the nutritional efficacy of functional foods and support preventive healthcare. • Probiotic fermentation improves phytochemical bioavailability and functionality. • Strain-specific effects of Lactobacillus and Bifidobacterium are critically reviewed. • Quantitative data compares bioavailability in dairy and plant-based fermented foods. • Fermentation enhances antioxidant and anti-inflammatory phytochemical activity. • Review outlines challenges, clinical insights, and future directions in food wellness.