>>The bioavailability of current oral preparations is relatively low

If you mean bioavailability in the sense of how much gets into the bloodstream - and the beneficial effect is on the community of critters living in the gut, shouldn't that low bioavailability be a feature, not a bug?

Off topic: I ran across an interesting study on berberine, leptin, adiponectin, and adipocyte stem cell proliferation you might find useful as grist for the mill: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310165/

Also, if you're listening to the Peter Attia podcasts, the recent one with Ron Krauss (a leading light in the world of CVD) is really worth a listen. I broke down and subscribed, and now have access to the 'show notes'. Peter goes on about how great they are - and now that I've read a few, he's underselling them.

I've also started digging through what Chris Masterjohn has to say about nutrition (found him while I was trying to figure out MTHFR) - and some of that ties in with your recent article on GlyNAC (methyl donors).

Thanks for writing this stuff!