Metabolic Disorders, Gut Microbiome, and Cancer Immunoregulation

Introduction

A recent review published in the Journal of Physiology and Biochemistry investigates the complex interplay between metabolic disorders, the gut microbiome, and their influence on immune regulation in cancer. The study specifically focuses on the PI3K/AKT/mTOR signaling pathway, providing insights into how these factors contribute to cancer development and affect the efficacy of immunotherapy.

The Study in Detail

The review, authored by Abedi A, Moghaddam MM, Kachuei R, and Fooladi AAI, and published in the Journal of Physiology and Biochemistry (2026 Mar 20;82(1):30), synthesizes current understanding on the topic. The researchers are affiliated with institutions including the Tissue Engineering and Regenerative Medicine Research Center, Molecular Biology Research Center, and Applied Microbiology Research Center at Baqiyatallah University of Medical Sciences in Tehran, Iran.

The study highlights that metabolic disorders such as obesity, hyperglycemia (high blood sugar), and dyslipidemia (high blood lipids) can activate specific signaling pathways, notably PI3K/AKT/mTOR. This activation promotes abnormal cell growth, prolonged cell survival, and uncontrolled proliferation, all of which are hallmarks of cancer development. Furthermore, these metabolic conditions induce chronic inflammation, leading to increased expression of proteins like PD-L1 on immune and cancer cells. PD-L1 plays a crucial role in suppressing the immune system, allowing cancer cells to evade immune surveillance and reducing the body's ability to combat tumors.

The review also emphasizes the significant role of the gut microbiome, a dynamic community of microorganisms in the intestine. The composition of this microbiome is heavily influenced by lifestyle, diet, and metabolic health. Unhealthy conditions, including obesity and diabetes, are linked to alterations in gut microbiome composition, a state known as dysbiosis. This dysbiosis can lead to the production of substances like endotoxins, which increase gut permeability. This increased permeability allows inflammatory molecules to enter the bloodstream, activating immunosuppressive immune cells. Consequently, the immune system's anti-tumor response is weakened, and the effectiveness of immunotherapies, such as PD-1/PD-L1 inhibitors, may be reduced.

Conversely, the study notes that beneficial bacteria, such as Bifidobacterium and Lactobacillus, can produce short-chain fatty acids (SCFAs). These SCFAs are known to strengthen the immune system and can potentially improve the response to cancer immunotherapy.

Assessment

This review provides a comprehensive overview of the complex interactions between metabolic health, the gut microbiome, and cancer immunology. Its strength lies in synthesizing disparate findings into a coherent narrative that underscores the multifactorial nature of cancer development and treatment response. By focusing on the PI3K/AKT/mTOR pathway and immune checkpoints like PD-L1, the authors illuminate key molecular mechanisms. The inclusion of the gut microbiome as a critical mediator adds another layer of understanding to the systemic effects of metabolic dysfunction on cancer. A limitation, inherent to review articles, is that it does not present new experimental data but rather consolidates existing knowledge. However, it effectively identifies areas for future research and therapeutic intervention.

Practical Relevance

The findings of this review have significant practical implications for both cancer prevention and treatment. They underscore the importance of maintaining metabolic health through lifestyle choices, including diet and physical activity, as a strategy to potentially reduce cancer risk. Managing conditions like obesity, hyperglycemia, and dyslipidemia could directly impact the cellular pathways that drive cancer progression and immune evasion.

Furthermore, the emphasis on the gut microbiome suggests that dietary interventions and probiotic strategies aimed at fostering a balanced microbial community could enhance immune function and improve the efficacy of cancer immunotherapies. For individuals undergoing cancer treatment, particularly those receiving immune checkpoint inhibitors, attention to metabolic health and gut microbiome modulation might represent a valuable adjunctive strategy. This could lead to more personalized and effective cancer therapies in the future.

Conclusion

This review highlights that metabolic disorders and an imbalanced gut microbiome are critical factors influencing cancer development and the effectiveness of immunotherapy. By activating specific signaling pathways and promoting chronic inflammation, these conditions can enable cancer cells to evade the immune system. Maintaining metabolic health and a balanced gut microbiome emerges as a crucial strategy for enhancing immune function, potentially leading to reduced cancer risk and improved treatment outcomes.