The Host-Microbiome Interplay in Colorectal Cancer - Volume II

Due to the success of the original Research Topic, we have decided to launch a Volume II of The Host-Microbiome Interplay in Colorectal Cancer.

The microbial community residing in the digestive tract represents a dynamic and diverse ecosystem encompassing bacteria, parasites, protists, fungi and viruses. Intestinal microbiota is assembled following birth and progressively develops into a unique niche within the host influencing key physiological processes such as digestion and nutrient absorption, host metabolism, protection from enteric pathogens, and immune reactivity. Indeed, the gut microbiome has been widely recognized for its role in maintaining the integrity of the intestinal barrier and modulating both local and systemic immune response. Increasing evidence highlights that a well-balanced host-microbiome relationship is critical for overall health, whereas dysregulation of this interaction directly contributes to diseases such as colorectal cancer (CRC), inflammatory bowel disease (IBD), cardiovascular disease, diabetes mellitus, and even mental illness.

CRC is a result of accumulated genetic mutations in the epithelial cells of the colon coupled with dysregulation of the immune response within the mucosa or the tumor environment. While genetic background can explain the development of CRC, greater than 90% of the disease risk is attributable to environmental factors such as age, lifestyle and diet, where alteration in microbiota can occur. For instance, disruption of the intestinal epithelium barrier, where the host-microbiome interactions are compromised, enables commensal or pathogenic bacteria to translocate into the mucosa that promotes inflammation and cytotoxicity leading to carcinogenic mutations. This was particularly established for E. Coli, B. fragilis, E. faecalis whereas other species could have antitumoral properties through production of antioxidants or anti-inflammatory metabolites.

Although numerous microbial taxa have been associated with CRC and IBD-associated CRC, we still need a comprehensive understanding of how the microbiome’s dynamic mechanistically affects the homeostasis of the host responses to unravel early diagnostic biomarkers, predict disease progression and improve conventional therapeutic strategy such as immune- or chemotherapy.

Therefore, in this Research Topic Volume 2, we welcome Original Research Articles and Brief Research Reports both on human and animal studies relevant to human diseases, Reviews, and Mini-Reviews that cover the following areas of focus:

1. Mechanism of carcinogenesis/tumorigenesis induced by the microbiome.
- mechanism of DNA damage/mutation/repair caused by microbial toxins and metabolites.
- effect of pathogen-associated molecular pattern (PAMP) and damage-associated molecular pattern (DAMP) signaling on intestinal pathology.
- influence of dietary components and medical drugs on microbiome-driven tumorigenesis.
2. Impact of microbial communities and their metabolites on shaping the tumor-associated immune response.
- differences between mucosal and intra-tumoral microbiomes.
- mechanism of immune resistance including modulation of tumor microenvironment (TME), immune checkpoint inhibitors, and tumor-associated macrophages (TAM).

Through this collection, we aim to highlight innovative studies that would pave the way toward microbiome-targeted CRC treatment.

Article types and fees

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Editorial
• FAIR² Data
• General Commentary
• Hypothesis and Theory
• Methods
• Mini Review
• Opinion
• Original Research
• ... View all formats

Articles that are accepted for publication by our external editors following rigorous peer review incur a publishing fee charged to Authors, institutions, or funders.

Article types

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Editorial
• FAIR² Data
• General Commentary
• Hypothesis and Theory
• Methods
• Mini Review
• Opinion
• Original Research
• Perspective
• Review
• Systematic Review

Keywords: CRC, microbiome, DNA damage, microbial genotoxicity, PAMP/DAMP, TME, immune checkpoint, TAM, immunotherapy

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.