Parabiotics as Next-Generation Microbiome Therapeutics: Insights into Mechanisms, Evidence, and Therapeutic Potential.

Parabiotics (also termed paraprobiotics) are defined as non-viable microbial cells or their components, including peptidoglycans, teichoic acids, surface proteins, that confer health benefits without requiring viability which distinguishes them from traditional probiotics. Their non-viable nature eliminates risks such as microbial translocation, bacteremia, and sepsis, making them suitable for vulnerable populations including immunocompromised, critically ill, paediatric and elderly individuals. In addition, parabiotic exhibit improved thermal stability, extended shelf life, and easier incorporation into functional foods, nutraceuticals, and pharmaceutical formulations without cold-chain requirements. Mechanistically, parabiotics retain immunomodulatory, anti-inflammatory and have barrier-enhancing activities through interactions with host pattern recognition receptors, including Toll-like receptors, modulation of cytokine responses, and reinforcement of gut epithelial integrity. Preclinical and clinical studies support their therapeutic potential such as in case of heat-killed Lactobacillus acidophilus LB (L. acidophilus) has shown efficiency in managing acute paediatric diarrhoea, while heat-inactivated Lacticaseibacillus paracasei PS23 (Lcb. paracasei) has demonstrated improvements in muscle strength and inflammatory markers, including reduced C-reactive protein and interleukin-6 and increased interlukin-10 in elderly individuals. Similarly, inactivated Lactiplantibacillus plantarum (Lpb. plantarum) and Bifidobacterium strains have been associated with benefits in irritable bowel syndrome, atopic dermatitis, respiratory infections, visceral fat reduction, and antibiotic-associated dysbiosis. Synergistic combinations with prebiotics, postbiotics and related bioactives further enhance therapeutic outcomes in inflammatory, metabolic and infectious conditions. Advances in metagenomics, next-generation sequencing, proteomics, metabolomics, CRISPR-Cas systems, and synthetic biology are accelerating strain characterization, functional evaluation, and scalable production. Despite ongoing challenges in standardization and regulated harmonization, parabiotics represent a safe and effective approach for microbiome-targeted interventions. This review synthesizes current evidence on their therapeutic applications, technological advancements, and translational potential, highlighting their role in precision health and next-generation functional nutrition.