Along with exposing China to foreign cultures, the Mongols’ reopening of the Silk Road brought foreign diseases to China. Bubonic Plague, the “Black Death” that killed possibly half the European population in the 14th century, actually hit China first. The plague began in central Kyrgystan and killed up to 25 million people in China in the 1330s and 1340s, about two decades before it first arrived in Europe.
After reading this I believe the Silk Road had negative effects as well as positive ones. While it helped spread culture and trade, it also spread deadly diseases. It's pointed out that the Black Death actually started in Asia (surprisingly) not Europe like most us thought.