Aggarwal S, Ranjha R, Paul J. Neuroimmunomodulation by gut bacteria: Focus on inflammatory bowel diseases. World J Gastrointest Pathophysiol 2021; 12(3): 25-39 [PMID: 34084590 DOI: 10.4291/wjgp.v12.i3.25]
Corresponding Author of This Article
Surbhi Aggarwal, PhD, Postdoctoral Fellow, Research Associate, Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Hauz Khas, Delhi 110016, India. aggarwalsurbhi28@gmail.com
Research Domain of This Article
Gastroenterology & Hepatology
Article-Type of This Article
Minireviews
Open-Access Policy of This Article
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: http://creativecommons.org/licenses/by-nc/4.0/
World J Gastrointest Pathophysiol. May 22, 2021; 12(3): 25-39 Published online May 22, 2021. doi: 10.4291/wjgp.v12.i3.25
Neuroimmunomodulation by gut bacteria: Focus on inflammatory bowel diseases
Surbhi Aggarwal, Raju Ranjha, Jaishree Paul
Surbhi Aggarwal, Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi 110016, India
Surbhi Aggarwal, Raju Ranjha, Jaishree Paul, School of Life Sciences, Jawaharlal Nehru University, Delhi 110067, India
Raju Ranjha, Field Unit Raipur, ICMR-National Institute of Malaria Research, Raipur 492015, Chhattisgarh, India
Author contributions: Aggarwal S conceptualized and wrote the paper; Ranjha R and Paul J performed the review and editing of the paper.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Surbhi Aggarwal, PhD, Postdoctoral Fellow, Research Associate, Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Hauz Khas, Delhi 110016, India. aggarwalsurbhi28@gmail.com
Received: December 14, 2020 Peer-review started: December 14, 2020 First decision: February 14, 2021 Revised: March 1, 2021 Accepted: April 20, 2021 Article in press: April 20, 2021 Published online: May 22, 2021 Processing time: 150 Days and 21.2 Hours
Abstract
Microbes colonize the gastrointestinal tract are considered as highest complex ecosystem because of having diverse bacterial species and 150 times more genes as compared to the human genome. Imbalance or dysbiosis in gut bacteria can cause dysregulation in gut homeostasis that subsequently activates the immune system, which leads to the development of inflammatory bowel disease (IBD). Neuromediators, including both neurotransmitters and neuropeptides, may contribute to the development of aberrant immune response. They are emerging as a regulator of inflammatory processes and play a key role in various autoimmune and inflammatory diseases. Neuromediators may influence immune cell’s function via the receptors present on these cells. The cytokines secreted by the immune cells, in turn, regulate the neuronal functions by binding with their receptors present on sensory neurons. This bidirectional communication of the enteric nervous system and the enteric immune system is involved in regulating the magnitude of inflammatory pathways. Alterations in gut bacteria influence the level of neuromediators in the colon, which may affect the gastrointestinal inflammation in a disease condition. Changed neuromediators concentration via dysbiosis in gut microbiota is one of the novel approaches to understand the pathogenesis of IBD. In this article, we reviewed the existing knowledge on the role of neuromediators governing the pathogenesis of IBD, focusing on the reciprocal relationship among the gut microbiota, neuromediators, and host immunity. Understanding the neuromediators and host-microbiota interactions would give a better insight in to the disease pathophysiology and help in developing the new therapeutic approaches for the disease.
Core Tip: Dysbiosis in gut bacteria is a well-established factor, and the abnormality in the enteric nervous system is an emerging aspect that influences the gut inflammation. Both of them contribute to inflammatory bowel disease (IBD) pathogenesis by modulating the host immune response. Through this review, we linked the two pathological mechanisms and explained how neuroimmunomodulation by gut bacteria play a crucial role in IBD. We elaborated all the known neuromediators produced by gut bacteria and the role of each neuromediator as well as the respective gut bacteria in inflammatory signaling pathways especially in IBD.
