Was kind of interesting, though perhaps not unexpected given the amount of bacteria in fresh and even cooked foods and everywhere else etc - especially in the general air both indoors and out.
Our water pipes crawl with millions of bacteria:
www.sciencedaily.com/releases/2015/12/151216082553.htmOr the full study:
/www.jstage.jst.go.jp/article/jsme2/30/1/30_ME14123/_pdf-----
Of note maybe. In the full study they found mycobacterial biofilm in the drinking water distribution system but did not identify the species. Mycobacteria are pretty common but given the recent studies on MAP and isolation from drinking water and showers and studies showing they and other mycobacteria are resistant to chlorine this might lend a little more credibility to those MAP findings. The mycobacteria represented a pretty high percentage of the biofilm - again though, all depends on the species be it MAP or other.
Anyway - was just an interesting article in general.
Makes you think: We probably get exponentially more 'probiotics' every single hour just from drinking water, eating and breathing than from any store bought pill or powder.