Insular Resting State Functional Connectivity is Associated with Gut Microbiota Diversity.

Author: Curtis K1,2, Stewart CJ3, Robinson M4, Molfese DL1,2, Gosnell SN1,2, Kosten TR1,2,5, Petrosino JF3, De La Garza R II1,2,5, Salas R1,2,5
Affiliation: <sup>1</sup>Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, Texas, 77030, USA. <sup>2</sup>Michael E DeBakey VA Medical Center, Houston, TX, 77030, USA. <sup>3</sup>Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA. <sup>4</sup>Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, 77030, USA. <sup>5</sup>Department of Neuroscience, Baylor College of Medicine, Houston, Texas, 77030, USA.
Conference/Journal: Eur J Neurosci.
Date published: 2018 Dec 16
Other: Special Notes: doi: 10.1111/ejn.14305. [Epub ahead of print] , Word Count: 244

The gut microbiota has recently gained attention as a possible modulator of brain activity. A number of reports suggest that the microbiota may be associated with neuropsychiatric conditions such as major depressive disorder, autism, and anxiety. The gut microbiota is thought to influence the brain via vagus nerve signaling, among other possible mechanisms. The insula processes and integrates these vagal signals. To determine if microbiota diversity and structure modulate brain activity, we collected fecal samples and examined insular function using resting state functional connectivity (RSFC). Thirty healthy participants (non-smokers, tobacco smokers, and electronic cigarette users, n=10 each) were studied. We found that the RSFC between the insula and several regions (frontal pole left, lateral occipital cortex right, lingual gyrus right, and cerebellum 4, 5 and vermis 9) were associated with bacterial microbiota diversity and structure. In addition, two specific bacteria genera, Prevotella and Bacteroides, were specifically different in tobacco smokers and also associated with insular connectivity. In conclusion, we show that insular connectivity is associated with microbiome diversity, structure, and at least two specific bateria genera. Furthemore, this association is potentially modulated by tobacco smoking, although the sample sizes for the different smoking groups were small and this result needs validation in a larger cohort. While replication is necessary, the microbiota is a readily accesible therapeutic target for modulating insular connectivity, which has previously been shown to be abnormal in anxiety and tobacco use disorders. This article is protected by copyright. All rights reserved.

PMID: 30554441 DOI: 10.1111/ejn.14305