Ibrahim_2025_Foods_14_

This study aimed to isolate and screen lactic acid bacteria (LAB) with neuroprotective potential for food applications. Fifteen strains were screened for probiotic potential properties, gamma-aminobutyric acid (GABA) production, and acetylcholinesterase (AChE) inhibitory activity. Lactobacillus delbrueckii AY8 and AY15 demonstrated the strongest probiotic potential, AChE inhibitory activity, and GABA production. Whole-genome sequencing confirmed genes linked to these probiotic and neuroprotective traits. To assess their functionality in a food matrix, the strains were used as adjunct cultures in fermented milk with and without jujube kernel powder (JP). Fermentation with the AY8 strain in JP-fortified milk significantly increased bioactive compounds, resulting in higher total phenolic content (235.75 mg GAE/g), flavonoids (114.07 mg RE/g), and superior antioxidant activity (110.24 mg Ascorbic equivalent/100 g). This biotransformation led to a remarkable increase in AChE inhibition, with the AY8-fermented sample achieving 30.66% inhibition, significantly higher than the JP control (18.27%) and the plain control (12.30%). The combination also improved the product's viscosity and sensory profile. This study highlights the successful discovery of novel L. delbrueckii strains, whose application in a food model, when combined with a plant-based supplement, creates a functional food with enhanced neuroprotective potential, underscoring the role of microbial metabolism in food functionality.