Open AccessRole of gut microbiota-immunity axis in patients undergoing surgery for colorectal cancer: Focus on short and long-term outcomes
Author(s) -
Ilenia Bartolini,
Matteo Risaliti,
Maria Novella Ringressi,
Filippo Melli,
Giulia Nannini,
Amedeo Amedei,
Paolo Muiesan,
Antonio Taddei
Publication year - 2020
Publication title -
world journal of gastroenterology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.427
H-Index - 155
eISSN - 2219-2840
pISSN - 1007-9327
DOI - 10.3748/wjg.v26.i20.2498
Subject(s) - dysbiosis , fusobacterium nucleatum , gut flora , colorectal cancer , bacteroides fragilis , microbiome , immunology , fusobacterium , cancer , biology , immune system , immunity , bacteroides , antibiotics , medicine , microbiology and biotechnology , bioinformatics , periodontitis , bacteria , genetics , porphyromonas gingivalis
Human body is colonized by a huge amount of microorganisms mostly located in the gastrointestinal tract. These dynamic communities, the environment and their metabolites constitute the microbiota. Growing data suggests a causal role of a dysbiotic microbiota in several pathologies, such as metabolic and neurological disorders, immunity dysregulations and cancer, especially the well-studied colorectal cancer development. However, many were preclinical studies and a complete knowledge of the pathogenetic mechanisms in humans is still absent. The gut microbiota can exert direct or indirect effects in different phases of colorectal cancer genesis. For example, Fusobacterium nucleatum promotes cancer through cellular proliferation and some strains of Escherichia coli and Bacteroides fragilis produce genotoxins. However, dysbiosis may also cause a pro-inflammatory state and the stimulation of a Th17 response with IL-17 and IL-22 secretion that have a pro-oncogenic activity, as demonstrated for Fusobacterium nucleatum . Microbiota has a crucial role in several stages of postoperative course; dysbiosis in fact seems related with surgical site infections and Enterococcus faecalis (and other collagenase-producers microbes) are suggested as a cause of anastomotic leak. Consequently, unbalanced presence of some species, together with altered immune response may also have a prognostic role. Microbiota has also a substantial role in effectiveness of chemotherapy, chemoresistance and in the related side effects. In other words, a complete knowledge of the fine pathological mechanisms of gut microbiota may provide a wide range of new diagnostic tools other than therapeutic targets in the light of tailored medicine.