Metabolomics-guided valorization of lactic acid bacteria-fermented date pomace for functional food applications

Microbial fermentation provides a sustainable approach to convert agricultural byproducts into value-added functional ingredients. This study examined date pomace biotransformation using probiotic strains Lactobacillus acidophilus LMG 13550, Bifidobacterium longum LMG 13197, Pediococcus acidilactici MNL5, and a mixed culture (LBP) to develop synbiotic-rich formulations. Among all treatments, synbiotic mixed-fermented date pomace (SMFDP) showed the highest bioactivity, significantly surpassing single-strain fermentations (LAFDP, BLFDP, PAFDP) and the unfermented date pomace control (DP). SMFDP strongly inhibited key metabolic enzymes: α-amylase (73.55 ± 1.6 %), α-glucosidase (87.63 ± 1.5 %), pancreatic lipase (96.07 ± 1.7 %), and xanthine oxidase (76.72 ± 1.6 %). It also exhibited high antioxidant capacity, with elevated total phenolics (1442.98 ± 3.8 mg GAE/100 g) and flavonoids (441.83 ± 2.3 mg QE/100 g). In vivo studies using Caenorhabditis elegans confirmed that synbiotic mixed-fermented date pomace (SMFDP) enhanced lifespan, gut colonization, and fertility. UHPLC-Q-TOF-MS/MS metabolomics revealed enrichment of bioactive metabolites and gene–metabolite interactions linked to metabolic regulation. ICP-OES analysis showed improved mineral bioavailability after fermentation. Overall, SMFDP demonstrates strong potential as a sustainable, bioactive ingredient for managing metabolic disorders and exemplifies circular bioeconomy by transforming date-processing waste into high-value synbiotic products.