NUTRITIONAL AND MICROBIAL MODULATORS OF THE MICROBIAL ECOSYSTEM: PREBIOTICS AND PROBIOTICS

The gut microbiota is constantly being reshaped by lifestyle factors, primarily diet, and environmental factors; disruption of microbial balance is associated with numerous clinical conditions, including gastrointestinal diseases, obesity, diabetes, metabolic syndrome, inflammatory bowel diseases, and neuropsychiatric disorders. Probiotics are live microorganisms that, when consumed in sufficient quantities, provide health benefits to the host, and their effects largely depend on the strain. These effects include supporting epithelial barrier integrity, competitively excluding pathogens, producing short-chain fatty acids and antimicrobial molecules, regulating the immune response, and modulating the gut-brain axis. Selected probiotic strains belonging to the genera Lactobacillus, Bifidobacterium, Saccharomyces, and Bacillus have been reported to provide beneficial effects in various clinical conditions such as antibiotic-associated diarrhea, inflammatory bowel diseases, atopic diseases, mood disorders, and metabolic disorders. Prebiotics are defined as substrates that are resistant to the host's digestive enzymes and produce health benefits when fermented by specific microorganisms. In addition to inulin, fructooligosaccharides, and galactooligosaccharides, new classes of compounds such as polyphenols have also been found to exhibit prebiotic properties. Increased production of short-chain fatty acids by these compounds contributes to the strengthening of epithelial barrier function, regulating the inflammatory response, and modulating energy metabolism. Furthermore, the neuromodulatory effects of prebiotics on the gut-brain axis position them as a complementary biological intervention tool in the management of metabolic, inflammatory, and neuropsychiatric diseases. Synergistic approaches combining probiotics and prebiotics can enhance therapeutic efficacy by increasing the colony-forming capacity of target microorganisms. However, since the effects of both groups are influenced by variables such as strain characteristics, dosage, duration of administration, and the individual's microbiome profile, the decision regarding their use should be carefully considered, especially in susceptible patient groups. Therefore, based on evidence, probiotics and prebiotics should be administered carefully and tailored to the individual's specific clinical needs.