Postbiotics are increasingly recognized as a predominant group of biotherapeutic agents sourced from the microbial secretome, offering functional benefits, while circumventing the safety concerns associated with the application of live microbial consortia. These microbial derivatives are emerging as promising approaches for tackling complex diseases, encompassing cancer, autoimmune diseases, and metabolic disorders, through modulation of host cell signalling pathways, including G protein-coupled receptors (GPCRs), the NF-κB (Nuclear Factor Kappa B) pathway, and epigenetic regulatory pathways. Besides systemic effects, postbiotics may also have localized effects, such as epithelial regeneration, modulation of fibroblast functions, and control of collagen remodelling. Eventually, the scale-up in the production of postbiotics has initiated new avenues in improving sustainable agriculture and environmental biotechnology. This comprehensive review attempts to integrate mechanistic insights and translational applications, highlighting the therapeutic potential of postbiotics across biomedical and ecological domains. These observations could pave the way to bridge the gap between microbiome regulation, precision medicine, and sustainable biotechnology, thereby positioning postbiotics as a versatile tool addressing some of the most pressing health and sustainability challenges of the 21st century.

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic inflammatory diseases resulting from complex interactions between host genetics, environmental factors, immune dysregulation, and the gut microbiome. Among environmental exposures, antibiotics have emerged as important factors of IBD risk and disease course because of their profound effects on intestinal microbial communities. This review synthesizes current evidence on the class-specific effects of antibiotics on IBD, integrating epidemiological, mechanistic, and clinical studies to examine how different antibiotic classes influence disease susceptibility, progression, and microbiome recovery. Current evidence indicates that antibiotic-associated IBD risk varies according to antibiotic class, cumulative exposure, age at exposure, and antimicrobial spectrum, with broad-spectrum and anti-anaerobic agents showing the strongest associations. Mechanistically, antibiotics promote dysbiosis by depleting beneficial commensal bacteria, disrupting microbial metabolite production, expanding pathobionts and the intestinal resistome, and impairing epithelial barrier integrity and immune homeostasis. The review also discusses microbiome-preserving and microbiome-restorative approaches, including antimicrobial stewardship, fecal microbiota transplantation, prebiotics, probiotics, synbiotics, postbiotics, and dietary interventions, as potential strategies to mitigate antibiotic-associated dysbiosis. Overall, the evidence highlights the class-specific effects of antibiotics in IBD and underscores the importance of microbiome-informed antimicrobial stewardship and precision therapeutic strategies to optimize patient outcomes while minimizing long-term disruptions of host–microbiome homeostasis.