Laura Weyrich (VIDEO) Penn State This video is under embargo. Please login to access this video. Caption Laura Weyrich, associate professor of anthropology, Penn State, discusses her research suggesting that the Second Plague Pandemic of the mid-14th century may be associated with a shift in the composition of the human oral microbiome toward one that contributes to chronic diseases in modern-day humans. Credit Penn State Usage Restrictions Educational use only License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.