Role of Microbiome in Cancer Recovery

We often think of healing as something that happens only within our cells, but just as important are the trillions of microbes that live within us. This vast inner ecosystem, the microbiome, plays a crucial role in regulating immunity, digestion, metabolism, and even gene expression. In cancer care, supporting the microbiome can influence how well a person tolerates treatment and how they recover afterwards [1,2].

Disruption and Vulnerability
Chemotherapy, radiotherapy, antibiotics, and surgery can all disrupt microbial balance. Loss of beneficial species such as Bifidobacterium and Lactobacillus, combined with reduced microbial diversity, has been associated with increased inflammation, impaired gut barrier function, and greater susceptibility to treatment side effects [1,3]. Recognising and addressing this disruption is an important aspect of integrative oncology.

Testing Before Treatment
Baseline microbiome testing provides valuable insights into both the species present and the functional potential of the microbiome. Certain bacteria support the production of short-chain fatty acids (SCFAs), which help regulate inflammatory pathways such as COX-2 [1,2]. Others influence DNA repair and cell cycle regulation, including activity linked to tumour suppressor genes such as TP53 [1]. Conversely, imbalances may activate inflammatory signalling through NF-κB, which has been associated with tumour progression [1,4].

Some bacterial species, such as Fusobacterium nucleatum and certain Gammaproteobacteria, can metabolise chemotherapy drugs into inactive forms, potentially affecting treatment efficacy [2,5]. In immunotherapy, patients with higher levels of fibre-fermenting, SCFA-producing species often respond better than those with overabundant pro-inflammatory microbes [2,6]. Testing before treatment helps identify these dynamics and can inform personalised dietary and prebiotic strategies to support the body through therapy.

Immunotherapy and Microbiome Support
Emerging research suggests that faecal microbiota transplantation (FMT) may benefit some patients who do not initially respond to immune checkpoint inhibitors [7,8]. While promising, this approach remains experimental and requires specialised oversight.

During active immunotherapy, routine probiotic supplementation is not generally recommended, as current evidence is insufficient to confirm safety or benefit. Instead, dietary strategies that naturally support microbial diversity such as a variety of plant foods, polyphenol-rich foods, and edible mushrooms containing prebiotic fibres like beta-glucans are considered safer and may help support resilience [2,9]. Targeted prebiotic fibres may also be considered under professional guidance.

After Treatment: The Time to Rebuild
Recovery from treatment marks a critical phase for rebuilding microbial diversity and resilience. Retesting at this stage can provide objective feedback on areas of imbalance and guide personalised strategies, which may include multi-strain probiotic formulations, prebiotic fibres such as human milk oligosaccharides (HMOs) or partially hydrolysed guar gum (PHGG), and a wide variety of plant foods [2,9]. Including edible mushrooms rich in beta-glucans may also help support microbial diversity as part of a broader, evidence-informed approach to recovery. By focusing on measured, data-informed strategies, patients can support recovery in a way that aligns with their individual microbiome profile.

Beyond Survival
Recovery from cancer is more than the absence of disease; it is a process of rebuilding vitality, resilience, and inner harmony. Recognising the microbiome as an active partner in this journey allows patients to support their wellbeing in a personalised, evidence-informed way. By incorporating microbiome testing both before and after treatment, patients and clinicians can gain objective insights into microbial balance and identify strategies tailored to individual needs, ensuring that interventions are guided by clinical data. This approach empowers patients to move from treatment into recovery with clarity, confidence, and a renewed sense of wellbeing.

References

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