Gut microbiota: Impact on 5-fluorouracil efficacy and toxicity

Cancer is one of the most prevalent and deadly diseases worldwide. Despite medical advances, the survival rate of patients with cancer remains poor, and v many standard chemotherapeutic choices are associated with toxic side effects that substantially impair their quality of life. 5-Fluorouracil (5-Fu) is a widely used chemotherapeutic drug. Administration of 5-Fu is known to cause diarrhoea and intestinal mucositis. Butyrate is a short-chain fatty acid produced during the fermentation of dietary fibre by the gut microbiota. Butyrate may mitigate 5-Fu's toxic effect of mucositis. In addition, butyrate enhanced the efficiency of 5-Fu. However, the pungent odour of butyrate renders it unpalatable to patients. The administration of butyrate-producing bacteria is a preferable alternative for patients seeking the positive effects of butyrate without an unpleasant taste. Furthermore, butyrate-producing bacteria could provide beneficial effects beyond butyrate production, including the restoration of microbial dysbiosis and anti-inflammatory effects. In this review, we provide an overview of the current research on butyrate-producing bacteria, concentrating on their possible effects and defence mechanism against 5-Fu toxicity, which indicates their potential applicability as an adjuvant treatment for patients with cancer.