It's an odd theory. Humans have very little free ammonia in their bodies. There are enzymes that quickly catabolize it to urea.
Second, nitrides seems like an odd product of ammonia metabolism. I've only ever heard of metal nitrides, nothing organic.
It's pretty well understood that bacteria on the skin metabolize the fatty acids in our sweat to short chain aliphatic acids (propionic acid, butyric acid, etc). If you've ever smelled those chemicals you'd see the resemblance.
Second, nitrides seems like an odd product of ammonia metabolism. I've only ever heard of metal nitrides, nothing organic.
It's pretty well understood that bacteria on the skin metabolize the fatty acids in our sweat to short chain aliphatic acids (propionic acid, butyric acid, etc). If you've ever smelled those chemicals you'd see the resemblance.