Effects of probiotics, prebiotics, and synbiotics on P53 and KI-67 in colorectal cancer: a scoping review.

Changes in the gut microbiota (GM) are closely linked to colorectal cancer (CRC) development, influencing tumor cell proliferation and apoptosis. Prebiotics, probiotics, and synbiotics have been proposed as modulators of GM and potential regulators of tumor progression through key molecular markers, such as p53 and Ki-67. In this sense, a scoping review was performed following PRISMA-ScR guidelines to map available evidence on the impact of prebiotics, probiotics, and synbiotics on p53 and Ki-67 expression in CRC. Search was conducted in PubMed, SciELo, BVS/Lilacs, Embase, and Web of Science databases without date or language restrictions. Nineteen studies were included (18 preclinical and one randomized clinical trial). Ten studies assessed p53, seven evaluates Ki-67, and two examined both markers. Most preclinical studies suggested that biotic supplementation modulates apoptosis and proliferation-related pathways, often through p53 activation or Ki-67 suppression, although directionality varied across strains and models. Biotic interventions appear to influence tumor proliferation markers in CRC with strain- and model-dependent manner. Nevertheless, the evidence remains limited by heterogeneity of the study design, dosage, exposure time, and biomarker assessment. Well-designed and strain-resolved clinical trials are required to clarify whether these findings have translational and therapeutic relevance in CRC management.