It will either help burn alot of calories, and help you lose fat, or allow you to eat alot more food than you are now, while not effecting your weight gain.
5 miles a day, could hinder your muscle mass gain, however to give you an idea, Will Smith runs 5 miles a day, and he is still pretty stacked. You just have to eat enough to offset the calories burnt if you want to gain.
Alchemist of Alcohol
In the long run the main source of fat loss is in your diet, no doubt a 5 mile run helps, but running is a very energy efficient movement for the body to perform. If fat loss is your goal look at your diet, but if you just like to run while bulking I would say you are probably good to go.
I really don't think you should run every day if you have bodybuilding goals. It will definitely make if difficult to maintain muscle mass while losing fat. Running 3 times per week when combined with a good weight training program is plenty. You'll get the benefits of running without going overboard.
i run 2 miles a day for 4-5 days a week, always fasted runs as well. Between that and the work i do (motorcycle tech in an open garage) i have lost a lot of fat but not much muscle. i have to eat like crazy though to make sure i get enough calories in.