Going in, I was expecting all of these interactions would be like the GWAS (genome wide association studies) interactions. I was expecting maybe single digit (max) percentage changes in the overall fitness / lifespan / etc.
But, if I understand the article correctly [1], different combinations of gut bacteria drove variations in lifespan by up to ~20% (which is a HUGE shift), which makes me a little skeptical.
All in all, a fascinating, if very unclear study.
They are very interesting correlations, but mapping the cause-consequence relationship is probably one of the biggest challenges in modern biological research; in this context & diseases like (many) cancers. In an ideal world, we really would like to have that degree of understanding to be able to develop effective, targeted cures (the holy grail of modern medicine?)
Finally, there's a lot of 'buzz' around microbiomes / microbiomics etc, etc. But I think one needs to be cautious in interpreting these results. This twitter thread [2], on an article / paper claiming modulation of schizophrenia by gut microbiome, is an articulate criticism(IMO) of such a claim.
In general (not the fly paper referred to in [1]), I think a significant fraction of microbiome / trait association studies, as exemplified by the schizophrenia study discussed in [2], are just throwing stuff up & seeing what sticks; and they are.. perhaps not the most rigorous of ways of doing science..
Finally, a slightly older, but still good article in NY Times that discusses some of the issues around the hype, etc. [3]
[1] https://www.pnas.org/content/115/51/E11951
[2] https://threadreaderapp.com/thread/1095012297200844800.html
[3] https://www.nytimes.com/2017/03/06/upshot/exciting-microbe-r...
[multiple edits to improve readability :~]