If you were an athlete, you would care to learn about the routines of other athletes. You may not play the same sport, but you care how they train.
Similarly, if you are an intellectual, you would care to learn about the routines of other intellectuals. You may not hold the same beliefs, but you care how they train.
Sure! Mutaflor is quite expensive, and it has to be kept in the fridge. I ordered it in Germany, but it should be available internationally, perhaps with other brand names. It's one of the few bacterial strains that is proven to help Ulverative Colitis (http://en.m.wikipedia.org/wiki/Mutaflor).
Homemade Kefir and Water Kefir are made by fermenting milk or sugarwater. It's a wild ferment, so it's critical that the culture you get on eBay or craigslist is in a good state. So it's advisable to have a hard look and smell at the kefir you are producing. Keeping the kefir acidic is crucial so the good strains (L-Bacilli and certain funghi) can outcrowd the strains you don't want in there. Kombucha works similarly, but I haven't used if for long.
While I tried lots of things, milk and Water Kefir worked best by far. I can't remember what L-Bacilli supplements I tested, but I got the impression that they did not do as much as Mutaflor or the Kefir. But the number of bacteria in Kefir is ridiculously higher than in most supplements, so that might be the reason.
Almost forgot.. I have low stomach acid, so I regularly drink (unpasteurized, unfiltered) apple cider vinegar. This might prevent "bad" strains from getting a grip, but I can only speculate.