Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA. Sam and Rose Stein Institute for Research on Aging, University of California San Diego, La Jolla, CA 92093, USA. Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA. Department of Computer Science and Engineering, University of California San Diego, La Jolla, CA 92093, USA. Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA. Center for Microbiome Innovation, University of California San Diego, La Jolla, CA 92093, USA. Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA. VA San Diego Healthcare System, La Jolla, CA 92161, USA.