[teekno]

I was shocked to read that the gut microbiome's gene set is about 150 times larger than the human gene complement [1]. I don't know a ton about microbiology, but it seems like that wouldn't drastically increase the time to sequence these microbes since we are talking about total set size, not the size of individual genomes? There is still so much to learn from the human genome alone - I fully expect many of our next great medical advances will come from studying these gut flora.

Hopefully that will also bring a little more science to the probiotics industry :)

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3779803/

[tstactplsignore]

It's a bit of a tricky comparison. Bacterial genomes are jam-packed full of protein-coding genes, while human genomes have genes spread out between much larger regions of both "junk" (viral elements, pseudogenes, and repetitive elements) and regulatory regions.

A human genome is 3 billion base pairs, and a bacterial genome is ~3 million base pairs. Considering there are probably 100-1000 bacterial species of clinical / gut ecological importance in a person's gut, it happens to sort of work out that it takes roughly the same amount of sequencing to sequence your gut microbiome as it does your genome.

Studies like this one do not do that. They only sequence marker genes which describe which bacteria are there (however, this process doesn't include all bacteria, doesn't tell you what those bacteria do, or what their small differences are). It's like a census where you just ask for people's last names.

That being said, after reading I think this was a nice little study. It had a small sample size but pretty clear effects that fit in with a lot of priors that we already have about the gut with regards to butyrate production by specific species.