The study of cancer has for long focused on genetic mutations, aberrant cell signaling, and the microenvironment of tumors. Recently, a less obvious but profoundly influential player has entered the spotlight: the oncobiome. This term refers to the cancer-associated changes in the microbiome, or what’s called “oncobiosis”—the opposite of a healthy, balanced state known as “eubiosis.” Understanding the oncobiome opens up new avenues for comprehending cancer pathogenesis, progression, and even treatment response. The human microbiome, comprising a diverse array of microorganisms such as bacteria, viruses, protozoa, fungi, and archaea, inhabits the body of every individual. This complex ecosystem establishes commensal, symbiotic, and pathobiont relationships, drawing growing interest for its potential role in carcinogenesis.

What Is the Oncobiome?

The “oncobiome” encompasses the collective community of microorganisms (bacteria, viruses, fungi) that inhabit our bodies and whose composition is altered in the presence of neoplastic, or cancerous, diseases. These changes shift the community from a state of balance (eubiosis) to dysbiosis (oncobiosis), with significant consequences for cancer biology. The European Union-sponsored ONCOBIOME network has sparked an
international effort to identify gut microbiota-related biomarkers in oncology, that explores the effects of the microbiota on GI permeability and metabolism,  antimicrobial resistance, and antitumor immune responses. This research has enabled diagnostic methods for gut dysbiosis that uses oncomicrobiome signatures associated with
cancer.

Multifaceted Interactions Between Microbiome and Cancer

Research demonstrates that the microbiome interacts with cancer on multiple fronts, influencing nearly all the hallmarks of cancer (Hanahan & Weinberg, 2011, 2000). From cellular metabolism to immune modulation, the oncobiome's influence is broad and powerful.

1. Cellular Function and Metabolism

Microbial communities can directly alter basic cellular functions. For instance, they impact:

• Redox Homeostasis: Microbial imbalance can shift oxidative stress levels within tissues. Sustained oxidative stress is known to damage DNA and contribute to the accumulation of mutations, thereby increasing transformation risk. Conversely, low oxidative stress driven by certain bacterial metabolites can exert cytostatic effects, slowing the growth of some cancers (Kovács et al., 2019; Sári et al., 2020).
• Metabolic Pathways: Dysbiosis can lead to altered metabolic gene expression, influencing cancer cell energy use and growth patterns (Sári et al., 2020; Miko et al., 2018).

2. Cancer Progression and Metastasis

The oncobiome also modulates:

• Epithelial-to-Mesenchymal Transition (EMT): Crucial for cancer cell migration and invasion, microbiome shifts can enhance or suppress EMT (Sári et al., 2020; Buchta Rosean et al., 2019).
• Cellular Movement & Metastasis: Changes in the microbiome influence the invasive and migratory potential of cancer cells, thereby affecting metastasis (Kovács et al., 2019).
• Angiogenesis: Some microbiome-derived factors can promote new blood vessel formation, facilitating tumor growth (Miko et al., 2018).

3. Immune Modulation

The immune system represents a double-edged sword in the context of cancer and the microbiome. The oncobiome can:

• Modulate Antitumor Immunity: Certain bacteria or their metabolites can either invigorate or suppress the immune response against tumor cells (Sári et al., 2020; Miko et al., 2018; Zitvogel et al., 2016).
• Influence Immunotherapy Response: Microbial composition can affect how well patients respond to therapies like immune checkpoint inhibitors (Routy et al., 2018; Gopalakrishnan et al., 2018).
• Drive Tumor-Promoting Inflammation: Persistent inflammation, often maintained by the dysbiotic microbiome, can sustain and accelerate tumor progression (Kiss et al., 2020; Yu, 2018).

4. Therapeutic Interactions

The microbiome is a critical mediator in the effectiveness and toxicity of anticancer therapies.

• Chemotherapy and Radiotherapy Modulation: Bacteria may influence the metabolism or distribution of chemotherapeutics, sometimes reducing efficacy or heightening toxicity (Bashiardes et al., 2017; Alam et al., 2020).
• Feedback Effects of Therapy on the Microbiome: Conversely, treatment regimens themselves can alter microbiome composition, with implications for subsequent therapeutic responses.

What Drives Oncobiotic Transformation?

Several lifestyle and environmental factors play a role in shifting the microbiome toward an oncobiotic state, including:

• Diet and Obesity: Nutritional habits and excess body weight have been correlated with predictable changes in the microbiome that may promote oncogenesis (Schulz et al., 2014).
• Smoking: Tobacco use disrupts microbial communities and is associated with higher cancer risk (Biedermann, 2013).
• Circadian Rhythm Disruptions: Alteration of sleep and activity patterns can influence microbial balance (Zarrinpar et al., 2016).
• Aging and Chronic Disease: Both natural aging and conditions like diabetes affect the microbiome (Zhang et al., 2019).
• Medication Use: Antibiotics and even probiotics can impact the risk for oncogenesis through microbiome modulation (Friedman et al., 2006; Mendoza, 2019).
• Exercise: Physical activity influences both overall health and the composition of the microbiome (Ticinesi et al., 2019).

New Frontiers in Oncobiome Research

Recent discoveries point to the complexity and adaptability of the microbiome:

• Interbacterial Signaling: Quorum sensing, where bacteria communicate to coordinate behavior, can finely adjust the microbial community, with potential implications for tumor biology (Li et al., 2019; Juhász et al., 2017).
• “Dead Cell” Signaling: Even components released from dying bacterial cells may shape resistance patterns and overall microbiome health (Bhattacharyya et al., 2020).

The Oncobiome as a Target for Precision Oncology

Recognizing the pivotal role of the microbiome in cancer leads to compelling therapeutic concepts:

• Manipulating the Microbiome: Targeting the oncobiome through diet, prebiotics, probiotics, or even fecal microbiota transplantation could one day become part of standard cancer care.
• Predicting Therapy Response: Microbial signatures might help predict who will respond best to specific immunotherapies.

Top 10 Herbs for Targeting the Oncobiome

Understanding the complex relationship between herbal therapies and cancer is rapidly evolving, thanks in part to research into the oncobiome (the collective microbiome associated with cancer and its microenvironment). For patients, clinicians, and researchers alike, there is increasing interest in herbs that can beneficially influence the oncobiome, potentially supporting standard therapies and improving quality of life.

Below, discover the top ten herbs and plant compounds identified for their impact on the oncobiome, with a look at the science behind their potential.

1. Turmeric (Curcuma longa)

Curcumin, the active compound in turmeric, is well-studied for its anti-inflammatory, antioxidant, and antimicrobial properties. Several studies suggest curcumin’s ability to modulate the gut and tumor microenvironment, influencing the oncobiome in ways that may reduce inflammation and inhibit tumor growth.

2. Garlic (Allium sativum)

Garlic contains organosulfur compounds that can modulate immune response and reduce oxidative stress. Its effect on supporting healthy gut flora is well documented, and emerging research suggests that allium vegetables may play a protective role in cancer prevention through these microbiome interactions.

3. Ginger (Zingiber officinale)

Gingerols and shogaols, the major constituents of ginger, are known for their anti-inflammatory and anti-cancer properties. Ginger has been shown to influence the diversity and abundance of beneficial gut bacteria, potentially impacting the oncobiome and supporting healthy cellular processes.

4. Scutellaria baicalensis (Baicalin)

Baicalin, derived from Chinese skullcap root, demonstrates anti-cancer activity via antioxidative and immunomodulatory functions. It has also been linked to the regulation of gut microbiota, supporting the hypothesis that baicalin may beneficially modulate the oncobiome.

5. Artemisinin

Extracted from sweet wormwood (Artemisia annua), artemisinin is best known for its use in malaria treatment but is now being explored for anti-cancer applications. Emerging studies indicate its activity against cancer cells may be partly mediated by effects on the gut microbiome.

6. Green-Hull Tincture of Black Walnut (Juglans nigra)

The green hulls of black walnut contain juglone and other phytochemicals with antimicrobial, anti-parasitic, and possible anti-tumor effects. While research is scarce, some evidence suggests that antimicrobial herbs like black walnut can shift the microbiome in favor of beneficial species, possibly reducing inflammation and supporting immune function.

7. Cannabis & Cannabinoids (CBD, CBG, CB)

Cannabinoids such as CBD (cannabidiol), CBG (cannabigerol), and other hemp-derived compounds exhibit anti-inflammatory, anti-cancer, and microbiome-modulating properties. Preliminary studies highlight potential interactions between cannabinoids and gut bacteria, which may help regulate immune surveillance and inflammation in the oncobiome context.

8. Black Raspberry Flavanols

Flavanols, particularly from black raspberries, are phytonutrients recognized for their cancer-preventive properties. They modulate the oncobiome by influencing beneficial gut flora, reducing inflammation, and enhancing the body’s natural antioxidant capacity.

9. Resveratrol (Polyphenol in Grapes and Berries)

While not specifically an herb, resveratrol-rich herbs and foods (like Japanese knotweed and grape skin) act on the microbiome and have direct anti-tumor effects. Resveratrol has been shown to reshape the gut flora, decrease tumor-promoting bacteria, and enhance beneficial species.

 

10. Ginseng (Panax spp.)

Ginsenosides, the active components of ginseng, are metabolized by gut microbes to more bioactive forms. Ginseng supplementation has been associated with positive shifts in the gut microbiome, boosting immune modulation and possibly impeding cancer progression.

 

The Role of the Oncobiome in Integrative Oncology

The interplay between herbal compounds and the oncobiome offers new avenues for integrative oncology. By targeting the microbiome, these herbs may help manage inflammation, modulate immunity, and enhance the effectiveness of conventional cancer therapies. While much of this research is still emerging and requires further validation in human studies, the connection between natural therapies and the oncobiome is a promising area for both cancer patients and scientists.

Always consult with your healthcare provider or oncology team before adding any new supplements to your regimen.

Learn More about Integrative Oncology

Curious about how integrative strategies can complement your cancer care? Explore more resources and the latest research on the oncobiome and herbal therapies by connecting with integrative oncology experts or visiting reputable cancer-focused organizations.

 

Sources

Curcumin and Cancer Cells: Evidence points to curcumin altering gut microbial composition, thereby mediating anti-cancer effects (Zhou et al., 2019, Cancer Letters).

Dietary Garlic and Cancer: Studies correlate high garlic intake with lower rates of certain cancers, possibly via influencing microbiota (Nicastro et al., 2015, Journal of Nutrition).

Ginger and the Microbiome: Animal models have shown positive shifts in gut microbiota with ginger supplementation (Wang et al., 2020, Molecules).

Baicalin’s Microbiota Interactions: Research shows baicalin can restore healthy gut flora and enhance anti-tumor immunity (Shen et al., 2017, Phytomedicine).

Artemisinin and Cancer: Preclinical work suggests alterations of the microbiota may boost the action of artemisinin in cancer models (Efferth, 2017).

The Microbiome-Cannabinoid Connection: Animal studies point to cannabinoids’ role in supporting a healthier gut environment (Nagarkatti et al., 2020, Frontiers in Immunology).

Black Raspberries and Colon Cancer: Consumption has been linked with favorable shifts in the gut microbiota and tumor suppression (Wang et al., 2013, Cancer Prevention Research).

Resveratrol, Tumor Growth, and Microbial Diversity: Clinical studies support microbiome-mediated tumor inhibition (Li et al., 2020, Nutrients).

Ginseng and Microbiota: Ginseng alters microbial balance, supporting anti-cancer immunity (Jin et al., 2022, Frontiers in Pharmacology).