Subject: cavity-causing bacteria in the mouth

Are the bacteria in my mouth which cause dental caries all the same species, or 
same family?  Do they all secrete the same kind of acid which breaks down 
enamel? Do these bacteria all eat the same thing?  That is, can I get cavities 
not just by eating candy bars but just by eating something seemingly benign, 
like celery, or bread? are some kinds of sugar less harmful than others, in 
terms of cavities?  (e.g., fruit juice versus 7-Up)  And is gum inflammation 
also caused by these same bacteria?  If so, is it because of the acid, again?  

Re: cavity-causing bacteria in the mouth