Author response: Gram-negative bacterial molecules associate with Alzheimer disease pathology

The comment by Dr. Mente raises critical issues for any postmortem microbial study. We agree that short postmortem intervals (PMI) and precautions against contamination before dissection procedures, coupled with negative blood and organ cultures, would help exclude possible contamination. In our study,1 PMIs were similar in Alzheimer disease (AD) compared to controls, brain procurement was performed before general autopsy, and identical procedures were used for removing and processing samples from AD and control brains. Therefore, contamination is unlikely to explain the markedly increased levels and differing cellular localization of Gram-negative molecules in AD compared to control brains in our study. Our study did not show bacteria in brain, but rather showed that molecules from bacteria are found in AD brain. This supports a growing literature of similar findings and may help explain how gut, and perhaps systemic microbiota, affect brain structure and function.2–4

Source: Neurology - June 12, 2017 Category: Neurology Authors: Zhan, X. Tags: WRITECLICK & amp;reg; EDITOR ' S CHOICE Source Type: research