There are approximately 20k protein-coding genes found in the human genome. This number is presumably very small when considering all the genomes found in the diverse microbes associated with the human body.

Is there an estimate for the total number of protein-coding genes found in human microbiome?

  • $\begingroup$ What is the relation between microbiome and human genome? $\endgroup$ Jul 23, 2014 at 13:46
  • $\begingroup$ Sorry, I mean only the human microbiome. $\endgroup$
    – boloyao
    Jul 23, 2014 at 13:48
  • $\begingroup$ Still?? Microbiome is the micor-organisms in human body. en.wikipedia.org/wiki/Microbiome $\endgroup$ Jul 23, 2014 at 13:50
  • $\begingroup$ Yes, I'm asking how many different genes are associated with a human and its resident symbionts, i.e. the number of protein-coding genes in the human genome + the number of protein-coding genes in the human microbiota. $\endgroup$
    – boloyao
    Jul 23, 2014 at 13:54

2 Answers 2


The Human Microbiome Project collected samples as shown in the image below from healthy volunteers:

enter image description here

They give an estimate of about 8 Million genes in the human microbiome, which is about 360x the number of genes in the human genome. See here for their press release with a lot of information. Additionally these two articles are as well interesting, if you want to dive deeper into the stuff:


Human Microbiome Project

According to Published data on HMP website:

  • The human microbiome consists of all the microorganisms that reside in or on the human body.
  • They may cause illness but some are necessary for good health.
  • There total count is 10 times more than Human cells.
  • ~800 genomes had been sequenced.
  • ~5000 Human sample had been used.
  • Include 14 disease project samples.
  • Total data stored on the DACC resource is 14 terabytes.
  • Total protein(~8 million) coding genes found to be 360x of number of human genes


[1] http://en.wikipedia.org/wiki/Human_Microbiome_Project

[2] http://commonfund.nih.gov/hmp/index

  • $\begingroup$ These look like numbers for the human genome only. $\endgroup$
    – boloyao
    Jul 23, 2014 at 13:55
  • $\begingroup$ If I had to guess, I'd estimate there are at least hundreds of thousands of different protein-coding genes associated with a human. $\endgroup$
    – boloyao
    Jul 23, 2014 at 13:56
  • $\begingroup$ I know. Can you edit the question, it is actually confusing? You need to know the number of genes in human Microbiome which have an effect in human genome? $\endgroup$ Jul 23, 2014 at 13:59
  • $\begingroup$ Thanks @Devashish I tried to clarify the question. I hope it makes more sense. And no, the genes do not have to be known to affect the human genome; they just need to be resident. $\endgroup$
    – boloyao
    Jul 23, 2014 at 14:10
  • 2
    $\begingroup$ The main text of your answer is entirely copied from a Wikipedia article. While you mentioned the source at the end of your post, you didn't mark the text as a quote. This is still plagiarism and not allowed on this site. You have to make clear any place where you quote a source verbatim. Answers should also not be taken entirely from external sources, they should be in your own words and quotes should be only for support. $\endgroup$ Jul 23, 2014 at 16:04

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