Postbiotics as Modulators of Gut Microbiota: Therapeutic Potential and Health Implications
: Postbiotics—non-viable microbial components or metabolites derived from probiotics—have emerged as promising modulators of the gut microbiota (GM), offering probiotic-like health benefits without the risks associated with live microorganisms. The GM is a crucial determinant of human health, and its disturbance (known as dysbiosis) is closely linked to conditions such as inflammatory bowel disease (IBD), colorectal cancer (CRC), sepsis, and metabolic syndromes. This review uniquely synthesizes mechanistic insights with therapeutic perspectives and summarizes current knowledge of the therapeutic potential of postbiotics to restore microbial balance and maintain intestinal homeostasis. Bioactive postbiotic molecules, including short-chain fatty acids (SCFAs), bacteriocins, exopolysaccharides, antimicrobial peptides, and vitamins, play key roles in inhibiting pathogens, enhancing beneficial bacterial populations, modulating immune responses, and strengthening epithelial barriers, and could also serve as an alternative to antibiotics. Postbiotics demonstrated therapeutic potential across multiple diseases, including IBD, CRC, metabolic syndrome, sepsis, and antibiotic-resistant infections, primarily through modulation of the GM, enhancement of intestinal barrier integrity, and regulation of immune responses. SCFAs, such as butyrate, reduce inflammation in ulcerative colitis; propionate induces apoptosis in gastric cancer cells. Most of the data in this area are preclinical, and further studies are needed. Evidence from preclinical and mechanistic studies suggests that postbiotics may represent a safe, effective alternative or adjunct to probiotics and antibiotics in managing GM-associated disorders.