IMPACT OF THE GUT MICROBIOTA ON THE IMMUNE RESPONSE TO ONCOLOGICAL IMMUNOTHERAPY: PROGNOSTIC BIOMARKERS AND MODULATION STRATEGIES

Abstract

This study aimed to comprehensively examine the relationships between the gut microbiota and the antitumor response, emphasizing the immunological mechanisms involved, the bacterial species linked to the efficacy or resistance to immunotherapy, possible microbial biomarkers, and new microbiome modulation strategies used in preclinical and clinical models. The methodology involved a narrative literature review conducted in databases such as PubMed, SciELO, ScienceDirect, and CAPES Journals. The results of the review showed that the gut microbiota plays an active role in immune regulation through metabolites, microbial antigens, and signals that affect T lymphocyte activation, antigen-presenting cell maturation, and cytokine production. Bacterial species such as Akkermansia muciniphila, Bifidobacterium longum, and Faecalibacterium prausnitzii were identified as being linked to a more favorable clinical prognosis, while others were associated with therapeutic resistance. Potential biomarkers from the microbiome were also discovered, such as taxonomic profiles, particular metabolites, and functional signatures. It is concluded that the use of the gut microbiota as a complementary therapeutic tool is a promising field, but it still needs methodological standardization, solid clinical validation, and in-depth mechanistic understanding for its full application in cancer immunotherapy.