All body pongs and the resultant stinks that infect clothing come from bacteria. People who develop a personal pong quickly are probably washing their clothes in cold water and not using an antibacterial in the mix. A shot of bleach and preferably hot water will do the trick.....but the bacteria can survive all sorts....So if you have a pong, wash all your clothes...even the clean ones in the same manner.
Shoes stink for the same reason. Bacteria thrive in the dark, damp recesses of the shoes. It is important to put clean, dry feet in clean shoes (washing your feet in some mild bleach solution helps enormously). Shoes need to be dried out in the sun where possible and the bacteria within needs to be hunted down and murdered.
If the shoes can be washed in hot water (some trainers can) do it...also use a little bit of bleach or nappy (daiper) solution such as Milton which contains a mild bleach and enzymes which will gobble the bacteria. If you can't wash them in a machine, you still need to kill the bacteria. Spraying rubbing alcohol in and over the shoes is effective (take out the insole first if you can), and some enzyme based products which you can buy from the pet store work wonders in shoes.
In every case of smells in clothing and shoes, bacteria are the problem...Kill them (and it's easy) and the stink will disappear.
PS..Just googled 'smelly shoes' and came up with umpteen squillion hits. Several recommendations for people with this problem involved taking a zinc supplement. Interesting!
"if at first you don't succeed....Redefine success"!