Bacillus coagulans is found in two forms:
1. the vegetative form which is a regular bacterial cell similar in structure to other probiotic bacteria (that we are more familiar with), and;
2. the spore form (the resilient goodguts variety), which has a naturally occurring dormant shell that can withstand many conditions such as heat, pressure, and extreme acid or alkaline conditions, any of which may kill vegetative bacterial cells.
The goodguts spore bacteria only becomes active in your gut.
One study you might find interesting is: Bacillus Coagulans As A Probiotic. Food Science & Technology Bulletin: Functional Foods 2010, 7(7): 103-109. D. Keller, S. Farmer, A.L. McCartney, G.Gibson.
This study discusses evidence for Bacillus coagulans effectiveness as a therapeutic probiotic and its heat stability overcoming the limitations of other probiotics.