Pacheco, Rodrigo2023-04-262023-04-262019-12Neural Regeneration Research Volume 14, Issue 12, Pages 2091 - 20921 December 20191673-5374https://repositorio.unab.cl/xmlui/handle/ria/49007Indexación: Scopus.The emerging role of gut microbiota as a key player in the development of neurodegenerative disorders: Mammals have evolved together with commensal microbiota to establish a symbiotic relationship in which they regulate reciprocally by synthesizing and responding to several common chemical substances. In this regard, gut microbiota constitutes a consortium of bacteria that not only participates in the degradation of nutrients, but also produces metabolites, fatty acids and neurotransmitters that can act on the enzymes and receptors expressed in eukaryotic cells, which considerably affects the physiology of the host and contribute to maintaining homeostasis (Lyte, 2013). According to the important role that gut-microbiota plays in maintaining homeostasis, alterations in the composition of gut-microbiota (dysbiosis) have consistently been involved in the development of neuropsychiatric, metabolic, autoimmune and neurodegenerative disorders. With respect to this last point, human and animal model researches have shown that the presence of some precise bacteria or the absence of some beneficial components in the gut microbiota of genetically susceptible individuals could trigger the development of Parkinson’s disease (PD), Alzheimer’s disease (AD), multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS). For instance, an increase of Proteus mirabilis in the composition of gut microbiota and excess production of short-chain fatty acids in the intestinal mucosa have been shown to promote the development of PD in several animal models (Sampson et al., 2016; Choi et al., 2018). On the other hand, it has been demonstrated that the butyrate producing bacteria, Butyrivibrio Fibrisolvens, was selectively decreased in the intestinal microbiota of animals genetically susceptible to ALS, and the administration of butyrate significantly attenuated the disease development disease (Zhang et al., 2017). Notably, in a study conducted with 34 pairs of discordant twins for MS, the results show that the composition of the intestinal microbiota from healthy twins was different from that obtained from twins with MS (Berer et al., 2017). Furthermore, using a mouse model of MS that develop the disease spontaneously in a specific-pathogen-free environment, the experiment showed that the mice developed a severer disease when they received the transfer of gut-microbiota from twins with MS than from healthy twins (Berer et al., 2017). Significant dysbiosis has also been implicated in AD patients, including the alteration in the composition of several bacterial taxa, such as Bacteroides Actinobacteria, Ruminococcus, Lachnospiraceae and Selenomonadales (Zhuang et al., 2018). Supporting these data obtained from AD patients, studies conducted in mouse models and recently also in Drosophila have shown that dysbiosis of the intestinal microbiota produces cognitive deterioration and neurodegeneration. Thus, the composition of gut microbiota plays a fundamental role in controlling homeostasis in central nervous system (CNS), and avoiding neurodegenerative disorders.enNeurodegenerative DisordersT-cellsGut-MicrobiotaDysbiosisHomeostasisArtículoAtribution 4.0 International (CC BY 4.0)DOI: 10.4103/1673-5374.262582