PROBIOTICS AND PREBIOTICS: MECHANISMS, BENEFITS, AND CHALLENGES – A NARRATIVE REVIEW

The human gut microbiota harbours numerous microbiota which includes archaea, fungi, viruses and bacteria. A balanced and healthy gut microbiota is essential for maintaining optimal physiological functions and thus the overall health and well-being. The state of a balanced gut microbiome is known as eubiosis, while dysbiosis is condition where an imbalances or disruptions in the gut microbiota, occurs. Dysbiosis has been associated with a range of diseases including gastrointestinal disorders, metabolic syndrome, neurological disorders chronic inflammation etc. The term probiotics refers to live microorganisms that, when ingested in adequate amounts, confer health benefits. The emergence of using probiotics therapeutically to repopulate the gut with eubiotic microorganisms and improve health introduces many new concepts.  On the contrary, prebiotics are food components that promote the growth or metabolism of beneficial microorganisms (e.g., bacteria & fungi). They can alter the gut microbiome makeup. Both probiotics and prebiotics have been effective in a variety of diseases. Nevertheless, concerns over standardization and safety dictate rigorous assessment of strains/formulations. New innovative therapeutic strategies are emerging due to recent advances in the understanding of Postbiotics activity and novel concepts such as symbiotics. This review highlights the existing literature regarding the mechanisms of probiotics and prebiotics in general, their health effects on various diseases as evidenced by animal models or intervention studies, also drawing attention to some controversies linked with these agents, which are still under investigation or revisiting after new high-quality evidence emerged mainly related to metabolic features such as weight loss.