The Colombian Exchange had good and bad effects on people on both sides of the Atlantic. Sadly the effect in the Americas was mostly bad.
The Colombian Exchange saw the introduction of such products as corn (maize) and potatoes to Europe, which greatly improved the diet of most Europeans. The end result was healthier people who lived longer and who gave birth to healthier offspring, resulting in a population explosion. The primary negative effect was the introduction of syphilis to Europe, which reached epidemic proportions before the method of transmission (it is an STD) was discovered.
In the Americas, animals such as pigs, horses, cattle and sheep were introduced, as well as cereal grains such as wheat and oats. Their effect was completely overshadowed, however by devastating diseases such as small pox, measles, and mumps. The inhabitants of the Americas had no natural resistance to these diseases, and as a result thousands died many years before any direct contact with Europeans. The diseases travelled so fast that in some areas, over ninety percent of the population was eradicated before European contact. In one of the more cynical chapters of history, Europeans on occasion used the Indian's lack of resistance for a form of germ warfare: they gave Indians blankets during cold weather which they knew to be infested with smallpox.
So while Europe benefited with some cost, the human toll in the Americas was much more pronounced.