The Association between the Gut Microbiome and Development and Progression of Cancer Treatment Adverse Effects

SIMPLE SUMMARY: Treatment of cancer can cause a multitude of unwanted effects including nausea, vomiting, diarrhoea, fatigue, cognition changes and weight loss. We also know that the microbiome of the gut can be altered by cancer treatments. In this review we investigated the existing evidence from human studies that supported a link between changes in the gut microbiome and the occurrence of the unwanted effect. We found that whilst there is some evidence linking gut microbiome and nausea, vomiting and diarrhoea, more research with people undergoing cancer treatment is required to expand our understanding and to investigate if modulation of the gut microbiome can be an effective treatment for unwanted effects. ABSTRACT: Adverse effects are a common consequence of cytotoxic cancer treatments. Over the last two decades there have been significant advances in exploring the relationship between the gut microbiome and these adverse effects. Changes in the gut microbiome were shown in multiple clinical studies to be associated with the development of acute gastrointestinal adverse effects, including diarrhoea and mucositis. However, more recent studies showed that changes in the gut microbiome may also be associated with the long-term development of psychoneurological changes, cancer cachexia, and fatigue. Therefore, the aim of this review was to examine the literature to identify potential contributions and associations of the gut microbiome with the wide range of adverse effects from cytotoxic cancer treatments.