ABSTRACT Psychobiotics have gained interest for their role in gut–brain communication through the production of short‐chain fatty acids (SCFAs). This study evaluated the postbiotic potential by analyzing the SCFA profile, antioxidant capacity, and serotonergic effects of cell‐free supernatant (CFS) obtained from Lactiplantibacillus plantarum 299V and Limosilactobacillus fermentum LC40. During controlled fermentation, the strains accumulated SCFAs, with L. fermentum producing higher levels of butyrate and propionate, whereas L. plantarum reached acetate levels comparable to those of L. fermentum LC40. CFS showed strong antioxidant capacity, characterized by a test‐specific profile: CUPRAC (1664.76 and 1626.67 µM TE), ABTS (440.31 and 438.77 µM TE), and DPPH (164.00 and 168.35 µM TE) for L. fermentum and L. plantarum . Cellular assays using RIN‐14B enterochromaffin‐like cells revealed strain‐specific responses : L. fermentum CFS maintained cell viability at low concentrations (10–25 µM butyrate‐equivalent) and promoted serotonin release at moderate doses (50–100 µM); in contrast, L. plantarum required higher butyrate‐equivalent levels (100–200 µM) for maximal serotonergic activity but showed a slight decrease in viability. These findings underscore the complementary antioxidant and serotonergic potential of psychobiotic‐derived CFS, reflecting the integrated activity of SCFAs in a complex postbiotic matrix, supporting their application in functional foods targeting gut and brain health.
Ana‐Maria et al. (Thu,) studied this question.