beneficial e coli (bec) is always depleted under infectious problems. bec is not to be confused with pathogenic e coli. bec serves as the major probiotic in the colon and is responsible for population of other probiotics species, without adequate amounts the minor probiotics cannot take hold. bec also produces enzymes that kill off pathogenic bacteria and probably yeast as well. there are many studies done in europe concerning it, the product is produced by a german lab and is called mutaflor, they have studies posted on their site.
I was told by a leading lab that the sickest people are those who show little or no bec. :(