Your experience with probiotics and the Human Microbiome Project

Just wondering if anyone would care to share their views / experience on the the use of probiotic nutritional supplements and the National Institutes of Health Human Microbiome Project .
Personally , I was surprised to find that after starting to take a probiotic nutritional supplement a few years ago I no longer experienced 'Bangkok Belly' on my yearly trips to Thailand, which previously required at least one course of medication upon arrival and sometimes would flair up again during my usual 3-4 week stays in Thailand , Cambodia , Laos and Indonesia.
Also a friend of mine who lives in the US and suffered with irritable bowel syndrome for many years experienced complete remission after his gastroenterologist recommended he start taking a daily probiotic.
As a physician and person with an academic interest in science I have followed the inception and progress of the National Institutes of Health Human Microbiome Project since it was started in 2008 ,but was genuinely startled to see such immediate and personal effects.
The basic premise of the study is that the microbes that live in us and on us have a profound effect on our health , resistance to disease and well being , and they set out to study 5 areas : The microbial communities that live in our mouth,gastrointestinal tract, urogenital tract, nasal passages and on our skin. The findings and results so far have been astounding and the second part of the project , The Integrative Human Microbiome Project was launched in 2014.
For more on the Project see the link below.
http://hmpdacc.org/ihmp/

I can tell you a little about my experience but obviously as a total non-expert. I had a staph infection in my hand that was sort of a freak accident. I took an antibiotic for it for about 6 weeks and was concerned about c. diff. or some other stomach problem from killing off beneficial bacteria in my intestinal tract. I don't know how much of a concern it was but I took probiotics and ate fermented foods just in case.

The probiotics did seem to help with digestion from the antibiotics, but I didn't notice any major differences although that could be since I was taking it as preventative measure. I have read about various probiotic strains being able to significantly impact health, including immune function and behavior. I do wonder though, whether taking oral probiotic supplements, even with billions of organisms, can significantly alter our microbiome. How well do they survive store shelves and how well can they brave our stomach acid and even then how different is our microbiome once they get to spot in our intestines where they compete with other organisms. As I said, though, I don't know a lot about it but it is interesting.