4 GUT MICROBIOTA-MEDIATED DRUG GASTROINTESTINAL TOXICITY
The gastrointestinal reaction is a commonly observed drug side effect
especially for chemotherapeutical agents and is characterized by nausea,
vomiting, diarrhea, and constipation (Ervin et al., 2020). Studies have
revealed the pivotal role of gut microbiota in therapeutic and toxic
outcomes of cancer therapy (Roy and Trinchieri, 2017; Gopalakrishnan et
al., 2018; Gori et al., 2019) and gut microbiome can even be used as a
tool to anticipate individual gastrointestinal toxicity (Wardill and
Tissing, 2017). It is believed that reciprocal interactions between gut
microbiota and innate immunity contributes to chemotherapy-induced
gastrointestinal toxicity (Secombe et al., 2019) and modulation of gut
microbiota by probiotics has been proven to attenuate gastrointestinal
toxicity of cancer therapy in human trials (Ciorba et al., 2015).
Chemotherapy-induced gastrointestinal side effects negatively influence
nutritional status and life quality of patients but most importantly
they intervene adherence to chemotherapy regiment, causing much
difficulty in the process of cancer therapy and prognosis (Ervin et al.,
2020) and therefore coping with this problem is of utmost importance in
cancer therapy. Gut microbiota hitherto has been correlated with
methotrexate, irinotecan, 5-fluorouracil, and mycophenolate
mofetil-induced gastrointestinal toxicity (Fig.4).