Plant-based beverage fermented by a potential probiotic co-culture of Pichia kluyveri and Lactiplantibacillus plantarum: bioactive composition, bioaccessibility, and modulation of antibiotic-induced gut dysbiosis.

Plant-based beverages are promising non-dairy matrices for delivering probiotic microorganisms and fermentation-derived bioactive compounds. The present study investigated the impact of fermenting a beverage composed of oats, almonds, and sunflower seeds with the potential probiotic co-culture Lactiplantibacillus plantarum CCMA 0743 and Pichia kluyveri CCMA 0615. The effects on beverage composition, bioaccessibility of bioactive compounds, and modulation of antibiotic-induced gut dysbiosis in BALB/c mice were assessed. After 24 h of fermentation, the fermented beverage exhibited high microbial viability, with L. plantarum and P. kluyveri reaching 9.32 and 7.05 log CFU/mL, respectively. The process facilitated carbohydrate utilization, acidification, and the generation of bioactive metabolites. Nutritional and functional profiles were enhanced, as evidenced by increased concentrations of linoleic acid, short-chain fatty acids, caffeic, gallic, and vanillic acids, vitamins B2 and B12, and γ-aminobutyric acid (GABA). Simulated gastrointestinal digestion demonstrated improved bioaccessibility of essential amino acids and B-complex vitamins. In vivo, a vancomycin-induced gut dysbiosis model was established, characterized by depletion of Bacillota and Bacteroidota and by the expansion of Pseudomonadota and Enterobacteriaceae-related taxa. Administration of the fermented beverage promoted microbial recovery, increasing the abundance of taxa associated with intestinal homeostasis and short-chain fatty acid production, particularly the Lachnospiraceae and Oscillospiraceae families. Collectively, these findings indicate that fermentation with a potential probiotic co-culture enhances the nutritional and functional quality of plant-based beverages and facilitates the restoration of gut microbial balance following antibiotic-induced dysbiosis, underscoring its potential as a functional non-dairy probiotic food.