This blog has some useful information on restoring a health gut flora
Art Ayers has also blogged on the topic a lot
so has Healthy Skeptic
You may not yet be aware that there are trillions of human cells in your body but for each human cells there are about ten times that number of gut bacteria.
There are major differences between the gut flora that thrive in an inflammatory environment and those that thrive in a less inflammatory situation.
While it is possible to change from those gut flora associated with obesity/diabetes and an inflammatory environment to those that prefer thrive in lean, less inflamed bodies it will take a lot longer than just taking a small capsule before bedtime though if it's live bacteria it could possibly contribute to change. But you've got to remember these are microscopic bacteria and your gut contains over a kg of them, If they were spread out one cell deep they'd more than cover a tennis court, so making changes is a long term slow business.
The above blogs will give you a better idea of how to proceed.
And here is a pubmed search of Free Full text papers that even if you just read the summaries will give you an idea of what gut flora can do
Click the link to free full text after following my link to PUBMED.
Remember this is a fairly new field of research.
Up to the year there were just 42 papers on the subject
ten years later There are 600 to read
One of the things that worries me is that we are now having more babies born by caesarian section and they will be like the germ free mice they use in gut flora experiments. We should really be ensuring these babies have a good gut flora available from birth so they can benefit from a healthy gut bacteria.
I also think the widespread use of antibiotics is probably doing far more harm than good. Dr Ayers has some very important points to make.