Spore forming bacteria are not some alien life form from another galaxy but rather a diverse group of very hardy bacteria. They come from many different bacterial species and some are harmful to human health and some are beneficial.
This type of bacterium is able to form a spore in which they protect their DNA when the going gets tough. They do this by duplicating their DNA and forming a protective membrane around it. Over the space of about 8 hours several protective coatings are put round the duplicate DNA - when the actual bacterium is killed this spore is released and can exist like this almost indefinately.
The formation of the spore by the bacterium allows it to be resistant to heat, freezing, chemicals, and other nasty environmental conditions that come along.
So the spore survives until conditions are right for it to "come to live" again.
Once in spore form the bacteria can survive hours of being boiled, disinfectants, alcohol, and all the usual methods by which we kill "germs". They are very, very hard to kill.
A bacterial spore was revived, cultured, and identified from the abdominal contents of extinct bees preserved for 25 to 40 million years in buried Dominican amber.
However for the species that are beneficial to our health this hardiness becomes a blessing.
The probiotic example of type of this type bacteria is Bacillus coagulans, formerly (and incorrectly) called Lactobacillus sporogenes.
Because it is a spore, this is a very tough probiotic that can survive considerable temperature differences and is not as "nampy-pampy" as many probiotics. No need to refridgerate this one. It will happily live in a bottle in your office drawer, laugh at the gastric juices as it travels through, and then become a transient resident of both small and large intestine.
It has not been studied in the depth that both Lactobacillus and Bifidobacterium have but has been used extensively in animal feed for many years.
Although the use of Bacillus coagulans spores as a probiotic has increased in recent years, "clinical evidence of its benefits are limited to only a few studies involving small patient populations" according to Drs Drago and De Vecchi of the Laboratory of Clinical Chemistry in Milan.
So it does need further studies with larger population groups before it can be compared against the more studied probiotics. However, this doesn't prevent many people from loving it. Just read some of the Digestive Advantage reveiws on Amazon. This bug has its fans!
You can buy Digestive Advantage IBS from Amazon. Over 500 mostly good reviews on this one so it ticks the box for a lot of people.
Digestive Advantage comes in several different types but they all appear to contain Bacillus coagulans.