Great Question!

I'm with Shelley on this one. Consider that the bacteria in your gut weigh several pounds, and that there are trillions of them. Taking a pill which only contains several million organisms which may or may not be alive when you take them, which may or may not make it through the stomach acid, which may or may not implant in your gut is not a very safe bet.

A much better approach to gut-bacteria is to make sure that the guts are clean, and that you eat a nutritious diet with plenty of fibre. This way you are feeding bacteria which are already suited to you and helping them multiply. If you increase your trillions of bacteria by even 1% that is much more than any pill can contain.

The regular consumption of lacto-fermented food is also a good idea, as most cultures have done this for thousands of years.