The role of the microscopic world: Exploring the role and potential of intratumoral microbiota in cancer immunotherapy Original paper
Researched by:
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Divine Aleru
ID
Divine Aleru
Read MoreI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
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Microbes
Microbes
Microbes, short for microorganisms, are tiny living organisms that are ubiquitous in the environment, including on and inside the human body. They play a crucial role in human health and disease, functioning within complex ecosystems in various parts of the body, such as the skin, mouth, gut, and respiratory tract. The human microbiome, which is […]
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Intratumoural Microbiota
Intratumoural Microbiota
With the growing understanding of the intratumoral microbiota’s influence on cancer progression, the next frontier in cancer therapy is microbiota-targeted interventions. By introducing beneficial microbes or altering existing microbial populations within tumors, therapies can be designed to modulate the immune system, promote tumor suppression, and improve drug efficacy. However, challenges remain in deciphering the complex relationships between microbes, tumor cells, and the immune system, necessitating more refined research methods and standardized approaches to translate these discoveries into clinical practice.
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Divine Aleru
Read More
Researched by:
-
Divine Aleru
ID
Divine Aleru
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Divine Aleru
What was studied?
This review investigates the role of intratumoral microbiota in cancer immunotherapy, focusing on how microbial components within tumors can influence cancer progression and therapeutic outcomes. The study covers the various ways intratumoral microbiota can interact with the immune system, either enhancing or suppressing antitumor immune responses. It explores the mechanisms through which specific microorganisms, such as Fusobacterium nucleatum and Bacteroides fragilis, modulate the tumor microenvironment (TME) and affect immune checkpoint therapy, highlighting their potential to be leveraged as therapeutic targets. The review also examines the origins of these intratumoral microbes, categorizing them into mucosal sites, normal adjacent tissues, and hematogenous spread, and how these sources contribute to microbial colonization within the TME.
Who was studied?
The review synthesizes findings from studies on various cancer types, including colorectal, breast, and pancreatic cancers. It specifically focuses on tumors that exhibit microbial colonization and how these microbes impact immune cells within the TME. The studies reviewed examine the presence of intratumoral bacteria, viruses, and fungi, as well as their relationship with immune cells such as T cells, NK cells, macrophages, and myeloid-derived suppressor cells (MDSCs). The research also discusses how specific microorganisms, including Fusobacterium nucleatum, Bacteroides fragilis, and Clostridium species, influence tumor progression and therapy responses by modulating immune checkpoints, inflammatory pathways, and the immune microenvironment.
Most important findings
The review highlights the dual role of intratumoral microbiota in cancer immunotherapy. On one hand, some microorganisms can stimulate immune responses and improve the efficacy of immunotherapy by enhancing T cell activation, promoting the formation of tertiary lymphoid structures (TLS), and facilitating antigen presentation. On the other hand, certain microbes contribute to immune suppression by increasing reactive oxygen species (ROS), promoting an inflammatory microenvironment, and inducing T cell inactivation, all of which facilitate cancer progression. The presence of Fusobacterium nucleatum in colorectal cancer, for instance, has been linked to immune suppression in microsatellite-unstable tumors, suggesting that intratumoral microbiota’s impact varies based on tumor type and immune status.
Key implications
The findings suggest that understanding the role of intratumoral microbiota could lead to innovative therapeutic strategies in cancer immunotherapy. Targeting specific microbial species or their metabolites could enhance the effectiveness of immune checkpoint inhibitors and other cancer treatments. The review also suggests that manipulating the intratumoral microbiota through interventions such as probiotics, antibiotics, or engineered bacteria could reshape the tumor microenvironment, promote immune activation, and overcome immune evasion mechanisms. However, the complex and condition-dependent effects of microbiota on cancer progression and immune response highlight the need for personalized treatment strategies. Future research should focus on identifying the precise microbial signatures in different cancers and determining how these signatures interact with the host immune system to guide therapeutic interventions.
Intratumoural Microbiota
With the growing understanding of the intratumoral microbiota’s influence on cancer progression, the next frontier in cancer therapy is microbiota-targeted interventions. By introducing beneficial microbes or altering existing microbial populations within tumors, therapies can be designed to modulate the immune system, promote tumor suppression, and improve drug efficacy. However, challenges remain in deciphering the complex relationships between microbes, tumor cells, and the immune system, necessitating more refined research methods and standardized approaches to translate these discoveries into clinical practice.
Breast Cancer
Traditionally linked to genetic predispositions and environmental exposures, emerging evidence highlights the microbiome as a critical and underappreciated factor influencing breast cancer progression, immune response, and treatment outcomes.