"Not new stuff" as in the research and use goes back a very long time as all the studies show. All outside of the US though. So Russia etc etc. I'm not sure of any products here in North America. There's a thread on here that mentions a product from Russia I believe. Someone was looking into it. In fact this is partially what got me super interested in it. If memory serves you can buy Phage therapy product literally at the pharmacy there as an alternative to antibiotics.
I think there's some FDA stuff around it here in North America (I might be wrong though) and that's why I think the prebiotic approach is interesting by labelling it this way if this is in fact the case. Maybe someone else knows of phage therapy products in the US though. It sounds to me like they are using/altering a food industry product and labelling it as generally safe because of this. I really don't know. Just guessing.
In any case, not all e-coli strains are bad and many are quite good for us and common to us as a protective commensal bacteria. So one would have to find out what strain/strains they are targeted towards.
Personally, I wouldn't go anywhere near the product without some well... to be honest I'd want like an FDA approval or some strong studies or something. At the same time I do find it quite interesting and am glad to see some companies going down this road.
Found this on a quick search a second ago -
Bacteriophages and Their Role in Food Safety
www.hindawi.com/journals/ijmicro/2012/863945/