I don't think they are particularly healthy, despite what people say. In essence you are getting rid of both the good AND the bad bacteria in your system, of which for healthy individuals, a positive good bacteria profile already exists (and takes time to build up). If you get it done make sure you take plenty of prebiotics/ probiotics afterwards - in so doing restoring your good bacteria, which assists in making the intestinal wall environment unlivable for bad bacteria, through the production of various minerals and nutrients. If you don't do this you may be leaving yourself prone to building up strains of e-coli and salmonaella