Happy Canada Day!
The following link has some interesting progress on the question of what intestinal bacteria do we need/not need.
It still does not answer the question of what nutrients particular bacteria might help produce…but progress.
I know research costs money but it is too bad that patents and such mean that the well-off benefit while the poor and ill often cannot afford it. 🙁
https://www.sciencedaily.com/releases/2019/06/190624111545.htm