Benefits of using probiotics as adjuvants in anticancer therapy (Review)

Cancer is the second leading cause of mortality worldwide and the constant search for novel therapeutics aims to increase the overall survival of the affected population. The human microbiota evolves with the host throughout the course of its entire life, as a direct consequence of individual diet and lifestyle habits. The gut microbiota tremendously affects human homeostasis and it has been widely observed that maintaining a healthy gut may prevent diseases, as well as ameliorate pathological conditions. According to the World Health Organization, probiotics may confer a health benefit on the host when administered in adequate amounts. Anticancer therapy often causes severe side‑effects, including gastrointestinal toxicity. Several clinical trials have highlighted the efficacy of administering probiotics to cancer patients receiving anticancer care, with proven efficacy in reducing gut‑related and life‑threatening side‑effects. To corroborate the clinical results, recent translational studies have indicated that the specific administration of selected bacterial gut species are capable of improving the immune check‑point immunotherapy clinical outcome. Lactobacillus rhamnosus GG (LGG), a model probiotic widely studied in oncology, has been proven to be beneficial when administered during anticancer therapy. In this review, we report the up‑to‑date clinical advancements obtained following the administration of probiotics during anticancer therapy, with particular focus on the promising probiotic strain LGG.