What is the role of microbiota in personalized medicine for oncology patients?

From the Guidelines

The microbiota plays a crucial role in personalized medicine for oncology patients by influencing treatment efficacy, toxicity, and overall outcomes, with the most recent evidence suggesting that specific bacterial species and microbiome diversity can predict treatment response and survival outcomes 1.

Role of Microbiota in Oncology

The gut microbiome can significantly impact how patients respond to cancer therapies, especially immunotherapies like immune checkpoint inhibitors (ICIs) such as pembrolizumab, nivolumab, and ipilimumab. Key findings from recent studies include:

• Specific bacterial species like Akkermansia muciniphila, Bifidobacterium species, and Faecalibacterium prausnitzii have been associated with better responses to immunotherapy 1.
• Antibiotics given shortly before or during immunotherapy can disrupt the gut microbiome and reduce treatment efficacy, with studies showing decreased progression-free survival (PFS) and overall survival (OS) in patients with non-small cell lung cancer (NSCLC) who received antibiotics before ICI treatment 1.
• The microbiome also influences chemotherapy effectiveness and side effects, with certain bacteria metabolizing drugs like gemcitabine and 5-fluorouracil, potentially reducing their efficacy.

Practical Applications

For practical application, oncologists should consider:

• Limiting unnecessary antibiotic use around immunotherapy administration to minimize disruption to the gut microbiome 1.
• Potentially incorporating microbiome testing to guide treatment decisions, as larger microbiome diversity has been associated with favorable response to PD-1 blockade 1.
• Recommending dietary interventions rich in fiber and fermented foods to support beneficial gut bacteria, such as Akkermansia muciniphila, which has been shown to improve the efficacy of PD-1 blockade 1.
• Exploring fecal microbiota transplantation to improve therapy responses, as some centers are already investigating this approach.

Underlying Mechanisms

The microbiome's influence on cancer treatment outcomes stems from its role in:

• Modulating immune function, with certain bacteria inducing interferon gamma+ CD8 T cells and facilitating the efficacy of ICI 1.
• Metabolism of drugs, with certain bacteria reducing the efficacy of chemotherapy agents like gemcitabine and 5-fluorouracil.
• Reduction of inflammation, which can impact treatment outcomes and overall survival.

From the Research

Role of Microbiota in Personalized Medicine for Oncology Patients

• The gut microbiota has been found to be strongly associated with the efficacy, toxicity, and side effects of chemotherapy, radiotherapy, and immunotherapy in cancer treatment 2.
• The human gut microbiota has exciting prospects for developing biomarkers to predict the outcome of cancer treatment, and multiple approaches can alter the gut microbiota composition, including faecal microbiota transplantation (FMT), probiotics, antibiotics (ATB), and diet 2.
• Consideration of the microbiome can improve antimicrobial utilization and treatment outcomes in oncology patients, and microbiome-based explorations can assist oncologists in optimizing treatment strategies for cancer-related infections as well as the cancer itself 3.

Pharmacomicrobiomics-Guided Precision Oncology

• Pharmacomicrobiomics is a rapidly developing field that promises to make significant contributions to predictive, personalized, preventive, and participatory (P4) medicine, particularly in the field of precision (P4) oncology 4.
• The microbiome plays a crucial role in health and disease, and several studies have shown that clinicians can harness insights from the microbiome to better predict treatment response, reduce side effects, and improve overall outcomes for cancer patients 4.
• Pharmacomicrobiomics will undoubtedly play a crucial role in shaping the future of cancer treatment in the era of P4 oncology as we continue to unravel the intricate relationships between the microbiome and cancer 4.

Gut Microbiota Modulation in Cancer Therapy

• The gut microbiota has a profound influence on both human health and illness, and it has recently come to light as a crucial element that influences cancer through a variety of mechanisms 5.
• The connections between the microbiome and cancer therapy are further highlighted by a number of preclinical and clinical evidence, suggesting that these complicated interactions may vary by cancer type, treatment, or even by tumor stage 5.
• Gut microbiota modulation, which aims to restore gut microbial balance, is a viable technique for cancer prevention and therapy given the expanding understanding of how the gut microbiome regulates treatment response and contributes to carcinogenesis 5, 6.