Is vagina licking harmful to the women?can bacterial be pass from the men's mouth to the women?

Cunnilingus: Yes, bacteria can obviously be passed, but the question is whether they are harmful. Sexually transmitted diseases can be transmitted in this fashion, although that would be unusual, even if you had the particular STD. Normal oral bacterial flora are unlikely to pose any risk to your female partner.

No.: Oral genital contact has very little risk for the women because the normal bacteria (called normal flora) are mostly the same in the mouth and the vagina.