Introduction: The gut microbiome has emerged as a crucial player in modulating the host’s immune system, with growing evidence linking its composition and function to the efficacy of cancer immunotherapies. Understanding the intricate interactions between the gut microbiota and immune responses can pave the way for novel therapeutic strategies to enhance cancer treatment outcomes.
Methods: This study systematically reviews and synthesizes findings from preclinical and clinical studies investigating the impact of gut microbiota on the efficacy of immune checkpoint inhibitors (ICIs) and other cancer immunotherapies. Advanced bioinformatics tools were utilized to analyze microbiome composition in patients undergoing treatment, while experimental models were employed to validate causal relationships and elucidate underlying mechanisms. Additionally, interventions such as probiotics, prebiotics, and fecal microbiota transplantation (FMT) were evaluated for their potential to modulate treatment responses.
Results: Findings highlight a significant correlation between gut microbiota diversity and treatment efficacy, with specific bacterial strains such as Akkermansia muciniphila and Bifidobacterium longum emerging as key modulators of immune responses. Mechanistically, these microbes influence the tumor microenvironment by enhancing antigen presentation, promoting T-cell infiltration, and reducing immunosuppressive factors. Clinical trials investigating microbiome-based interventions demonstrated promising results, with improved response rates in patients receiving FMT or microbiome-targeted therapies.
Conclusion: The gut microbiome plays a pivotal role in shaping the host’s immune landscape and determining the success of cancer immunotherapies. Future research should focus on integrating microbiome profiling into routine clinical practice to identify biomarkers for treatment stratification and develop personalized therapeutic approaches. Leveraging microbiome-targeted strategies offers a transformative opportunity to enhance the efficacy and safety of cancer immunotherapies.