Yes, to get clear results you should stop the probiotics at least 1 month before to do the test. My CDSA showed levels of lactos and bifidos but I didn't way enough time after stop taking kefir and probiotics. Anyway, I have never taken a Probiotic that have E. Coli and my test showed 3+ benefical E. Coli, so there is hope. Good levels of E. Coli are linked to good intestinal flora according to science. I will repeat my CDSA next year to see what happen but this time I will be away form Kefir and probiotics for at least two months before to send the sample.
Jorge