**The Challenging Triad: Microbiota, Immune System and Anticancer Drugs** The Challenging Triad: Microbiota, Immune System

Andreea Letitia Arsene, Cristina Manuela Dragoi, Alina Crenguta Nicolae, Daniela Elena Popa, George T.A. Burcea‐Dragomiroiu, Ion Bogdan Dumitrescu, Olivia Carmen Timnea and Denisa Ioana Udeanu Andreea Letitia Arsene, Cristina Manuela Dragoi, Alina Crenguta Nicolae, Daniela Elena Popa, George T.A. Burcea-Dragomiroiu, Ion Bogdan Dumitrescu, Olivia Carmen Timnea and Denisa Ioana Udeanu

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/65731

and Anticancer Drugs

#### Abstract

Gut microbiota is essential for the development of the intestinal immune system, protecting the host against pathogens and harmful inflammatory processes. Germ-free animals have smaller Peyer's patches, fewer immune cells and impaired immunoglobulin A (IgA) secretion, fewer intraepithelial lymphocytes, as well as compromised production of antimicrobial peptides. Mucositis (mucosal barrier injury) is a major oncological problem caused by chemotherapeutic agents. Intestinal mucositis translates into a broad spectra of clinical symptoms (diarrhea, vomiting) and can be worsened by neutropenia and antibiotics. Since IECs do not regulate intestinal homeostasis by themselves, but require symbiotic coordination with commensal bacteria and local gut leukocytic cells, the role of intestinal microbiota in the development and severity of mucositis induced by chemotherapeutic products became an issue. The present chapter reviews the interplay between microbiota, immune system, and anticancer therapy. The published researches in this field showed that microbiota has immunomodulatory effect on the anticancer immune response, both in the presence and in the absence of chemotherapy. Animal and human studies evoked that the anticancer response depends on microbiota variability.

Keywords: microbiota, immune system, anticancer therapy, efficacy, toxicity

© The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.
