Stool sample shows heavy growth of nontoxogenic e. Coli & streptococcus salivarius. Is this abnormal/problematic?

No. Assuming you are not symptomatic, these bacterial organisms are considered part of the normal gastrointestinal (GI) tract. The GI tract starts at the mouth and ends at the anus. Strep salivarius lives in the mouth whereas E. coli lives in the intestines. In only very rare instances does this strep cause illness. The type of E. Coli mentioned causes UTIs since the urinary and GI tracts are so close.