Background: Mental health disorders are a major global public health challenge. Psychobiotics have emerged as a promising strategy to modulate the microbiota–gut–brain axis. Whey and blueberry bagasse are agro-industrial by-products with potential for functional fermented matrices. Objective: To develop whey biotic blend (WBB) formulations enriched with blueberry bagasse and evaluate the impact of incorporation timing on functional properties, and to explore the neurobiological effects of a selected formulation. Methods: Three WBB formulations were prepared with Lactiplantibacillus plantarum 299v and PS128, differing in the timing of blueberry bagasse incorporation: Control, WBB-Before, and WBB-After. Physicochemical properties, microbial viability, composition, γ-aminobutyric acid (GABA), phenolic profile, and antioxidant and anti-inflammatory capacities were evaluated. Based on these results, WBB-After was selected as the sole formulation and advanced for testing in a lipopolysaccharide (LPS)-induced murine model. Results: All formulations supported probiotic growth (>8.6 log CFU/mL). Blueberry bagasse incorporation significantly influenced functional properties. WBB-After showed ~2.1-fold higher total phenolic content than WBB-Before and enrichment in anthocyanins and hydroxycinnamic acids, with higher antioxidant (≈24% by DPPH) and anti-inflammatory potential (≈19%), whereas WBB-Before exhibited ~20% higher GABA levels. In vivo, WBB-After showed improved recognition performance under baseline conditions (Control vs. WBB), although the overall group effect was marginal. No significant differences were observed in hippocampal cytokines or neuronal integrity markers under LPS-induced inflammation. Conclusions: The timing of blueberry bagasse incorporation shapes WBB functional properties. The selected formulation showed limited neurobiological effects under the evaluated in vivo conditions, highlighting the need for further studies.
Uribe-Velázquez et al. (Thu,) studied this question.