Biotechnological Approaches to Probiotics and Postbiotics through the Gut-Brain Axis Modulation.

The gut microbiome and gut-brain axis are central to systemic homeostasis, with dysbiosis implicated in neurodegenerative (Alzheimer's and Parkinson's) disorders and gastrointestinal conditions (inflammatory bowel disease, irritable bowel syndrome, and fibromyalgia). These conditions are marked by a reduction in beneficial taxa (e.g., Faecalibacterium prausnitzii and Bifidobacterium) and an increase in harmful ones (e.g., Escherichia coli and Clostridium scindens). Probiotic, prebiotic, postbiotic, and symbiotic interventions show therapeutic promise, but results can vary. Biotechnological advances, including CRISPR-Cas9 and genetic kill-switch systems, enable precision-engineered probiotics and postbiotics, though concerns about safety, genetic stability, gene transfer, and immune compatibility persist. Encapsulation and nanoencapsulation strategies improve microbial viability and site-specific delivery; i.e., microencapsulating Lactobacillus acidophilus and Bifidobacterium animalis in alginate-pectin matrices enhances survival during freeze-drying, storage, and gastrointestinal transit. Advancing clinical translation requires integrating multi-omics and machine learning with bioengineering approaches. This review examines the microbial-neural interface and surveys emerging biotechnological strategies for improving microbial-based therapeutics.