Some reasons why your belly button smells are due to dead skin cells, fungi, dirt, sweat and sometimes infections.
Poor hygiene and not cleaning your belly button often enough can lead to dirt, sweat and even lint accumulation in your belly button which can lead to odor of the belly button.
And infections such as bacterial or fungal infections can cause a foul odor and discharge from your belly button and can also cause swelling, redness and itching.
Cysts in the belly button can also cause odor and discharge of the belly button.
Even having belly button piercings can lead to infections and inflammation and lead to a smelly belly button odor.
To help alleviate the odor in your belly button you should wash your belly button regularly with some soap and water when showering and pay attention to the crevices and folds of your belly button.
Use a soft cloth or even a Q tip to gently cleanse the inside of your belly button.
And avoid use of any harsh soaps or lotions as they can worsen the problem and irritate the skin.
If the belly button continues to smell you should see a doctor or if you have discharge, itching or redness or if you suspect an infection of your belly button.