Interesting. Note this has not yet been peer-reviewed, so findings must be taken with an especially large pinch of salt even compared to your average paper. In this case, they only looked at 20 adults over 2 weeks, so I feel that any conclusions drawn here are circumstancial at best.

Apparently the reseach was funded by NIH and therefore at least partly the taxpayer. Seems like a bit of a strange study to fund, in my opinion nothing useful can possibly result from such a tiny study. I tried tracking down the specific grant they were given (they mention NIH award UL1 TR-002378 in the disclosure section of the paper but I can't find anything from that)