All I can say is, "avoid super wet-stored and Shu"..
Anyone who's seen the environment of Shu factories might assume that it's not the best place to produce health-related products. Not only that, but also sterilizers are done to rid of microbes after. And bad effect exists all over, in fermented products but that's not the reason we should abandon all fermented products. Bad effect exists in all over the foods, weeks ago British research discovered drinking a wine daily might severly lead to causing cancer..but wine's been consumed in West for thousands of yrs.
Examing microbe studies might be headaching,
I wonder if they seperated water-soluble microbe/not or what kind of samples of Puerh did they use..
I remember from Zhou Hong Jie 周紅杰's book, who's no.1 authority on micro-biological research, says those germs on Puerh are ignorable because other useful ones such as saccharomyces functions as 'killer yeast'..
I'm dumb on this kind of topic, and like everybody else I agree more studies should be done...