Limosilactobacillus reuteri DSM 17938 Produce Bioactive Components during Formulation in Sucrose.

Area of Science:

• Microbiology and Biotechnology
• Probiotic research
• Food science and technology

Background:

• Probiotic efficacy is often optimized through production parameter adjustments.
• Formulation steps, particularly lyoprotectant addition before freeze-drying, are less studied than fermentation.
• Process optimization typically focuses on yield and stability, neglecting bioactivity impacts.

Purpose of the Study:

• Investigate metabolic activities of *Limosilactobacillus reuteri* DSM 17938 during formulation with sucrose.
• Characterize metabolites produced during lyoprotectant conversion (lyoconversion).
• Assess the impact of lyoconversion on bacterial bioactivity, specifically immunomodulation.

Main Methods:

• NMR and GC-MS analysis to identify metabolites produced during sucrose conversion.
• Testing of lyoconverted samples and purified exopolysaccharides (EPS) in an immunomodulation model.
• Comparative analysis of bacterial cultivation with sucrose versus glucose as a sugar substrate.

Main Results:

• *L. reuteri* DSM 17938 consumed sucrose, producing an EPS glucan and other metabolites, including tryptamine and glycerol.
• Lyoconversion and purified EPS significantly increased IL-10 and IL-6 expression in peripheral blood mononuclear cells.
• Cultivation with sucrose enhanced sucrose conversion into EPS and metabolites, but lyoconversion negatively affected freeze-drying survival.

Conclusions:

• Bacterial metabolic activity during formulation (lyoconversion) can be leveraged to modify probiotic properties.
• Lyoconversion offers a strategy to potentially enhance probiotic bioactivity, demonstrated by immunomodulatory effects.
• Addressing the negative impact of lyoconversion on freeze-drying survival is crucial for future applications.