Congrats to uBiome, but honestly, the microbiome space is so nascent, this is an incredibly risky play. I haven't seen any data so far to suggest the microbiome plays a major role in disease. It's entirely speculation at this point.
As for the science around the microbiome role in metabolic, developmental and autoimmune disorder is observatory at best. I’ve yet to see a paper that took a human, changed their microbiome and observed X effect (beyond the obvious bacterial infection example).
But more to your point, using the mg data from their "healthy" population along with the open-label data in the literature seems like a good way to construct RCTs, no? Data from open label studies isn't speculative... it's just not phase 3.
In case you're curious, here are two papers on UC: https://www.ncbi.nlm.nih.gov/pubmed/28214091 and https://www.ncbi.nlm.nih.gov/pubmed/29052237
But also, it's not getting any easier to raise money for a real biotech, where you have to have scientific validation and might hurt people; it's easier to raise money when you're a blockchain biotech, and are promising whizzy vaporware that interacts with customers only in unregulated ways that can't be validated.
There is just a ton of money right now.
Even for companies like uBiome whose business strategy is “we’ll sequence your microbiome and <waves hands around furiously>”
It's only just started, but there is now a light at the end of the genetic/gene-therapy tunnel. With the approval of the first CAR last year (and it's success at curing children of leukemia), there's now a very real environment to produce valuable inventive biological products that are not just chemicals or antibodies.
Kite and Juno sales for ~$10B each earlier this year has done quite a bit for the field. Vapor always follows the good money, but it's not just that the money is cheap.