Garlic gives you bad breath three ways… initially due to the sulfuric compounds released when you chew the garlic meat, then the garlic itself promotes the growth of microbes that produce bad breath, and finally those same sulfuric compounds are readily metabolized in the body, enter your blood stream as allyl methyl sulfide and are exuded from your pores when you sweat, or passed into the air that fills your lungs, making your breath stink even if you brush your teeth or gargle.  Roasting garlic mellows the flavor and aroma.