During the 13th Probiotics, Prebiotics and New Foods Congress, Microbiomepost.com conducted an exclusive interview with Gianfranco Grompone, scientific director at BioGaia, who explored innovative strategies for developing next-generation probiotics, with a focus on Limosilactobacillus reuteri SM1738. 

This strain, one of the most extensively studied, represents a paradigm of co-evolution with the human gut microbiome—a system increasingly threatened by industrialization and Western lifestyles. Beyond its well-characterized molecular features, such as lipoteichoic acid, reuterin, 5′-nucleotidase activity, and immunomodulatory membrane vesicles, L. reuteri offers a model for strain reintroduction to restore beneficial host–microbe crosstalk. The presentation applied the Black Queen Hypothesis to probiotic innovation, illustrating how bacterial interdependencies can be harnessed for enhanced functionality. 

Two examples were discussed: (i) co-culturing L. reuteri with Bifidobacterium longum subsp. longum BGL47, which enhances L. reuteri’s bioactivity and is being evaluated in C-section-born infants; and (ii) a synergistic combination of two Lactobacillus strains with potential to promote serotonin production, an area of ongoing investigation. Together, these findings highlight how ecological and evolutionary frameworks can guide the discovery and application of probiotic strains with specific and clinically relevant effects.