Speaker: George Hoeferlin
Advisor: Dr. Jeffrey Capadona
Title: Investigating the Role of the Gut Microbiome on Brain Implants
Abstract: Intracortical microelectrode arrays (MEAs) record neuronal action potentials in the brain and can be paired with external systems to provide motor function rehabilitation to those with disabilities. Unfortunately, recording quality of MEAs consistently declines over the course of weeks to months, compromising device utility. Neuroinflammation from persistent indwelling of MEAs is considered a significant contributor to the decline in recording performance. Recent evidence suggests that the gut microbiome may play a role in brain health possibly via bacteria-specific metabolites or microbiota infiltrating through the blood-brain barrier. Therefore, we hypothesize that altering the gut microbiome in mice via oral antibiotics or probiotics could change the microbiome composition in both the brain and gut, affecting neuroinflammation and MEA performance. Weekly feces samples were collected for 16S bacterial analysis. After 12 weeks, brain samples were collected to analyze 16S bacterial compositions along with transcriptomics and proteomics to quantify effects on neuroinflammation. Bacterial culture was also performed to measure live bacteria in the brain and feces. Bacterial microbiome analysis indicate distinct populations of gut microbiome across groups, corresponding to treatment. Biweekly neural recording sessions indicated temporal differences in MEA recording performance. Acutely (Weeks 1-5), antibiotic-treated mice (79% active electrode yield, AEY) and probiotic-treated mice (75% AEY) showed significantly better MEA performance than control (68% AEY). Probiotic significantly outperformed antibiotic sub-chronically (Weeks 6-11) and chronically (Weeks 12+). Transcriptomic and proteomic analysis on brain tissue is underway to understand the correlation between MEA performance, microbiome composition, and neuroinflammation following MEA implantation and treatment. At minimum, our data suggest a connection between microbiome composition and recording performance. Such evidence provides a novel means for understanding and improving the lifetime of MEA devices to be used chronically in humans.