In this study, the functional and psychobiotic potential of three food-derived lactic acid bacteria (LAB) strains - OS4, O24, M3.3. - were investigated, evaluating them both as individual monocultures and as a combined multi-strain consortium (LAB MIX), standardized to 109 CFU/mL. The research was conducted in two consecutive phases to characterize their stability, metabolic activity, and potential synergistic effects under simulated gastrointestinal conditions.
In the first phase, a comparative screening was performed to evaluate the strains' and the MIX's mucin-adhesion capacity and stability during static in vitro gastrointestinal digestion, alongside the quantification of amino acid profiles to establish a metabolic baseline.
In the second phase, following the preliminary screening, the bacterial consortium (MIX) was selected for advanced validation using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®). This was achieved utilizing a TWINSHIME setup, a parallel multi-reactor system maintained at 37°C under anaerobic conditions that mimics the human gastrointestinal tract across the stomach, small intestine, and ascending, transverse, and descending colon segments. To evaluate the formulation under specific pathological conditions, the system was inoculated with fecal microbiota from a donor diagnosed with Alzheimer's disease (AD) and operated under a 38-day standardized protocol, which consisted of a 14-day stabilization period, a 14-day intervention phase with daily LAB MIX administration, and a final 10-day washout phase to assess the persistence of the intervention effects. This stage focused on monitoring the consortium’s impact on gut microbiota (GM) composition and evaluating subsequent shifts in amino acid metabolism under simulated colonic conditions.
Please consult the readme file for the explanation of the files in the dataset.
