"What is the cause?"
You answered the question yourself:
"After few courses of Antibiotics I noticed a Body Odor ."
The cause are Antibiotics ! You killed the best inside of you. You killed your best friends, good bacteria.
What is the cure?
The cure is always opposite of the cause.
You used Antibiotics because you were unhealthy.
Opposite of unhealthy is being healthy, living heathy, eating healthy, eating home made foods.
Opposite of antibiotics: Healthy diet, healthy lifestyle and FMT .