The gut-brain axis is a bi-directional integrated system composed by immune, endocrine, and neuronal components by which the gap between the gut microbiota and the brain is significantly impacted. An increasing number of different gut microbial species are now postulated to regulate brain function in health and disease. The westernized diet is hypothesized to be the cause of the current obesity levels in many countries, a major socio-economical health problem. Experimental and epidemiological evidence suggest that the gut microbiota is responsible for significant immunologic, neuronal, and endocrine changes that lead to obesity. We hypothesize that the gut microbiota, and changes associated with diet, affect the gut-brain axis and may possibly contribute to the development of mental illness. In this review, we discuss the links between diet, gut dysbiosis, obesity, and immunologic and neurologic diseases that impact brain function and behavior.
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The authors acknowledge the support of the National MS Society grant CA 1027A1/3 and the National Institutes of Health grants R41 AI110170/AI/NIAID and R56 AI098282/AI/NIAID in the preparation of this manuscript. The authors have licensed patents 8586029 and 8580278 to Symbiotix Biotherapies, and a patent 20140030807 pending.
Conflict of Interest
Javier Ochoa-Repáraz and Lloyd H. Kasper declare that they have no conflict of interest.
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This article does not contain any studies with human or animal subjects performed by any of the authors.
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Ochoa-Repáraz, J., Kasper, L.H. The Second Brain: Is the Gut Microbiota a Link Between Obesity and Central Nervous System Disorders?. Curr Obes Rep 5, 51–64 (2016). https://doi.org/10.1007/s13679-016-0191-1