This site cites five specific sources worth checking directly rather than assuming what they cover, spanning three different types of publication.
Chicory Root Inulin research on PubMed Central, resistant starch and gut fermentation on PubMed, a Bifidobacterium infantis overview on Healthline, a Clostridium butyricum entry on Wikipedia, and Akkermansia muciniphila research on PubMed Central.
Unlike sites that cite only NIH sources, this site mixes peer-reviewed research platforms with a consumer-health site and an encyclopedia entry — worth reading each source type differently, and remembering none represents a trial of the finished SodaTide formula.