Dairy-based matrices are commonly used as probiotic carriers; however, cereal-based substrates may provide additional bioactive advantages. This study evaluated whey-, rice-, and oat-based fermented formulations for γ-aminobutyric acid (GABA) production, antioxidant and anti-inflammatory capacity, and cytoprotective potential. Rice and oat (10% w/v) and whey were fermented for 24 h at 37 °C using Lentilactobacillus kefiri BIOTEC014, Latilactobacillus curvatus BIOTEC036, and Lactiplantibacillus plantarum strains 73a and PS128. Physicochemical parameters, microbial viability, GABA content, antioxidant capacity (DPPH and ABTS), and nitric oxide radical scavenging activity (NO-RSA) were determined before and after simulated gastrointestinal digestion. Fermentation led to acidification across all matrices, while post-digestion microbial viability remained above 7.4 log colony-forming units/mL in most formulations, except those fermented with BIOTEC036. Pre-digestion GABA concentrations varied among formulations (1.9-2.9 mM), while rice-based matrices showed superior GABA retention post-digestion (3–13% loss). Antioxidant capacity increased markedly post-digestion (up to 11–33-fold, by ABTS), whereas NO-RSA decreased but remained significantly higher in fermented samples than in unfermented controls. Multivariate analysis guided the selection of BIOTEC014- and PS128-based formulations, which showed cytoprotective effects in Caco-2 cells under H 2 O 2 -induced oxidative stress, including an increase in IC 50 from ≈31 to 49 μg/mL for the Whey–PS128 formulation. Overall, these findings highlight the relevance of strain–matrix interactions for developing fermented ingredients with bioactive and cytoprotective potential. • Fermented whey and cereal matrices supported lactic acid bacteria growth/survival. • Rice formulations retained more γ-aminobutyric acid after digestion (3–13% loss). • Antioxidant capacity increased after digestion in all samples (up to 11–33-fold). • After digestion, fermented samples stayed more anti-inflammatory than controls. • L. plantarum PS128-fermented whey showed cytoprotection under oxidative stress.
Uribe-Velázquez et al. (Sun,) studied this question.