Yarandi SS, Peterson DA, Treisman GJ, Moran TH, Pasricha PJ.  Modulatory Effects of Gut Microbiota on the Central Nervous System: How Gut Could Play a Role in Neuropsychiatric Health and Diseases.  J Neurogastroenterol Motil 2016;22:201-212.  https://doi.org/10.5056/jnm15146