Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 14, 2019; 25(2): 151-162
Published online Jan 14, 2019. doi: 10.3748/wjg.v25.i2.151
Role of diet and gut microbiota on colorectal cancer immunomodulation
Carolina Vieira De Almeida, Marcela Rodrigues de Camargo, Edda Russo, Amedeo Amedei
Carolina Vieira De Almeida, Department of Surgery and Translational Medicine, University of Florence, Florence 50134, Italy
Marcela Rodrigues de Camargo, Department of Surgery, Stomatology, Pathology and Radiology, Bauru School of Dentistry, São Paulo University, Bauru-Sao Paulo 17012901, Brazil
Edda Russo, Department of Experimental and Clinical Medicine, University of Florence, Florence 50139, Italy
Amedeo Amedei, Department of Experimental and Clinical Medicine, University of Florence and Department of Biomedicine, Azienda Ospedaliera Universitaria Careggi (AOUC), Florence 50139, Italy
Author contributions: De Almeida CV, de Camargo MR and Russo E prepared the manuscript; Amedei A provided overall guidance and supervision in writing the article.
Supported byThe Programma Attuativo Regionale (Toscana)” funded by FAS (now FSC) - MICpROBIMM, the Italian Ministry of University and Research (MIUR); and the Foundation ‘Ente Cassa di Risparmio di Firenze’.
Conflict-of-interest statement: The authors declare that they have no competing interests.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Amedeo Amedei, Associate Professor, Department of Experimental and Clinical Medicine, University of Florence, Viale Pieraccini 6, Florence 50134, Italy.
Telephone: +39-55-2758330 Fax: +39-55-2758330
Received: November 3, 2018
Peer-review started: November 5, 2018
First decision: December 12, 2018
Revised: December 20, 2018
Accepted: December 27, 2018
Article in press: December 28, 2018
Published online: January 14, 2019

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, and it is characterized by genetic and epigenetic alterations, as well as by inflammatory cell infiltration among malignant and stromal cells. However, this dynamic infiltration can be influenced by the microenvironment to promote tumor proliferation, survival and metastasis or cancer inhibition. In particular, the cancer microenvironment metabolites can regulate the inflammatory cells to induce a chronic inflammatory response that can be a predisposing condition for CRC retention. In addition, some nutritional components might contribute to a chronic inflammatory condition by regulating various immune and inflammatory pathways. Besides that, diet strongly modulates the gut microbiota composition, which has a key role in maintaining gut homeostasis and is associated with the modulation of host inflammatory and immune responses. Therefore, diet has a fundamental role in CRC initiation, progression and prevention. In particular, functional foods such as probiotics, prebiotics and symbiotics can have a potentially positive effect on health beyond basic nutrition and have anti-inflammatory effects. In this review, we discuss the influence of diet on gut microbiota composition, focusing on its role on gut inflammation and immunity. Finally, we describe the potential benefits of using probiotics and prebiotics to modulate the host inflammatory response, as well as its application in CRC prevention and treatment.

Keywords: Colorectal cancer, Diet, Inflammation, Immune response, Gut microbiota

Core tip: The host immune system plays a central role in colorectal cancer prevention and development. However, the immune response is deeply influenced by gut microbiota composition, which in turn is modulated by host diet. Therefore, diet could be used as a strong ally to prevent colorectal cancer and to support its treatment.