I’ve recently attended a talk on the advancements of human metagenomics projects. As the speaker admitted, the whole field is a researchers’ gold mine – almost all they find is new and interesting. There were couple of interesting points – mainly concerning how limited our knowledge about things in here is. For example, there was a unconfirmed feeling among microbiologists that in fact all modern microbiology is nothing more than biology of E. coli and relatives. Now we know that for sure – number of known to us microbial species is estimated at 0.5% of all existing microbial species. Also, I heard a nice story about polish doctor who described in 19th century Helicobacter pylori and its role in gastric diseases (there was a Nobel prize for that in 2005), wrote a book and then trashed the whole thing because he couldn’t grow the bacteria in a pure culture. Another important issue was amount of data and lack of new ways of handling them.
But the most interesting for me was a connection between human microbiome and diseases. Or rather a possibility of such connection. I am not aware of any single case when composition of human microbiome have been proven to influence chance of getting ill and I don’t think there will be a lots of such correlations found soon. My impression is that correlations are to be found when we have both, a complete human genome and a complete metagenome of all that lives on particular person – a human genobiome, as I’ve called it (BTW, word “genobiome” is not present in Google – is there a better word for that?). And I believe that getting the first full human genobiome will be the achievement compared to sequencing human genome for the first time. Not because of technical difficulties – because of the all discoveries that need to be made to make it happen. For example, human gut of all people carries a species doing some sulfur reaction – but its population is only up to few thousands cells. How many such cases are we have in our organisms? That is very good question. The field is brand new, and possibilities of speculations are endless.