Gut microbiota–brain axis in depression: The role of neuroinflammation. (18th December 2019)

• Record Type: Journal Article
• Authors: Carlessi, Anelise S.; Borba, Laura A.; Zugno, Alexandra I.; Quevedo, João; Réus, Gislaine Z.
• Other Names: Barrot Michel guestEditor.; Yalcin Ipek guestEditor.
• Is Part Of: European journal of neuroscience. Volume 53:Number 1(2021)
• Page Start: 222
• Page End: 235
• Publication Date: 2019-12-18
• Subjects: gut microbiota–brain axis -- inflammasome -- kynurenine pathway -- major depressive disorder -- neuroinflammation; Nervous system -- Periodicals; 612.8
• DOI: 10.1111/ejn.14631
• Languages: English
• ISSNs: 0953-816X

Abstract

Abstract: Major depressive disorder (MDD) is a psychiatric condition that affects a large number of people in the world, and the treatment existents do not work for all individuals affected. Thus, it is believed that other systems or pathways which regulate brain networks involved in mood regulation and cognition are associated with MDD pathogenesis. Studies in humans and animal models have been shown that in MDD there are increased levels of inflammatory mediators, including cytokines and chemokines in both periphery and central nervous system (CNS). In addition, microglial activation appears to be a key event that triggers changes in signaling cascades and gene expression that would be determinant for the onset of depressive symptoms. Recent researches also point out that changes in the gut microbiota would lead to a systemic inflammation that in different ways would reach the CNS modulating inflammatory pathways and especially the microglia, which could influence responses to treatments. Moreover, pre‐ and probiotics have shown antidepressant responses and anti‐inflammatory effects. This review will focus on studies that show the relationship of inflammation with the gut microbiota–brain axis and its relation with MDD. Abstract : Stress situations could lead to an impairment in the gut microbiota that in turn lead to a production of inflammatory mediators and a decrease in SCFAs. Changes in the gut microbiota may impact the gut barrier and to produce higher levels of inflammatory cytokines in the blood. In the periphery, the kynurenine pathways, metabolic, mainly toxic metabolic, are influenced by changes in the gut microbiota and inflammatory mediators. Products from microbiota impairment or periphery pro‐inflammatory cytokines could disrupt BBB and cross to the brain increasing cytokines releasing in the brain‐resident cells, including microglia and astrocytes. Changes in these glial cells influence brain networks that could be behind the onset of MDD.