Not just probiotics, bookittyrun, but also prebiotics
http://en.wikipedia.org/wiki/Prebiotic_(nutrition) have been hypothesized to be beneficial. Resistant starch
http://en.wikipedia.org/wiki/Resistant_starch is a prebiotic that is not widely known about that has been discussed some in this forum (a forum search will produce multiple threads touching on it).
One interesting thing about resistant starch is that it is potentially one of the best evidences for
raw Paleo diets. The research on it and some successful early experiments with it has even recently gotten many coctivore Paleoists to add raw foods like dried raw green plantains to their diets. It has caused quite a change of emphasis in some coctivore Paleo circles--instead of ridiculing raw Paleo, lauding Wrangham, crispy bacon or french fries, they have been focusing more on
raw/unmodified resistant starch. LOL
It's rather ironic that it's largely the coctivores who have recently been doing the most to support the benefits of
raw Paleo.
How odd it is that resistant starch is not discussed more in this forum. A weapon has been handed to rawists that is going largely unused.
I've been experimenting with raw resistant starch myself and getting some interesting positive blood glucose readings. It's too early for me to draw conclusions, though.
It used to be thought that no bacteria could survive in a healthy stomach (research in 1875 to the contrary was forgotten), but it was recently found that H pylori has been in the stomachs of many humans for probably around 60,000 years:
http://en.wikipedia.org/wiki/Helicobacter_pylori#EvolutionSince the rediscovery of h pylori, at least 127 other bacteria species have been found in human stomachs, though it's not yet known whether they reside there or just pass through:
http://www.ehow.com/list_6553962_viruses-bacteria-stomach.htmlhttp://www.livescience.com/515-bacteria-thrive-hostile-human-bellies.htmlThe gist of Miles' point is still correct in the sense that the probiotic bacteria that people use therapeutically are meant for the intestines, rather than the stomach. I think I read somewhere that most of them only make it as far as the small intestine and some don't make it past the stomach, including some intended for the colon, though at least some probiotics can reportedly be beneficial in the small intestine (
http://phys.org/news203333369.html). I also read some people claim that resistant starch can help bacteria make it all the way to the colon.