8.1 Microbes and genes

There is growing evidence that your human genes affect which microbes you’ll host.134 If you have your 23andme results, click through on the following links to see what your own genes are.

Secretor FUT2 allele

https://you.23andme.com/tools/data/?query=rs601338 If you are AA, then the good news is you are immune to norovirus but the bad news is you don’t digest fiber efficiently, which obviously changes the types of microbes you’d collect. With more data, we’d figure out which types of fiber work and which don’t in people like this. I know several people who are AA and have serious health issues — I’m convinced with this knowledge we’d just need to find the right (probably very weird) diet for them.

This gene correlates highly with Bifidobacterium.135



If you have A, you’re more predisposed to autoimmune conditions (like multiple sclerosis) but it’s believed the inflammation itself is caused by Klebsiella bacterium, of which interestingly I’m one of the very few people who shows any in their uBiome results. So am I immune to MS? Or if I somehow transmit my Klebsiella to an A carrier, could I infect them with MS?



I’m AC, which means I’m a slow metabolizer. 23andme thinks that I should stay away from coffee for that reason, but it’s not true! I drink as much as I like with no effects on sleep, and meanwhile uBiome’s functional KEGG test shows I’m 3x more efficient at caffeine metabolism than other people. Why? Because I must have a bug that does the work my genes don’t. Finding that one would be pretty cool.

Lactose intolerance


I’m A/G, but people who have a T variant are likely to be lactose intolerant.

HNF4A: diabetes risk in Asians


This one’s been proven in mice to be regulated in part by microbes.136

The site xcode.in has a summary of useful sites for getting the most out of your raw data

The website Genetic Life Hacks has another list of 23andme SNPS that relate to the microbiome.


Lim, Mi Young, Hyun Ju You, Hyo Shin Yoon, Bomi Kwon, Jae Yoon Lee, Sunghee Lee, Yun-Mi Song, Kayoung Lee, Joohon Sung, and GwangPyo Ko. 2017. “The Effect of Heritability and Host Genetics on the Gut Microbiota and Metabolic Syndrome.” Gut 66 (6): 1031–38. https://doi.org/10.1136/gutjnl-2015-311326.
Wacklin, Pirjo, Harri Mäkivuokko, Noora Alakulppi, Janne Nikkilä, Heli Tenkanen, Jarkko Räbinä, Jukka Partanen, Kari Aranko, and Jaana Mättö. 2011. “Secretor Genotype (FUT2 Gene) Is Strongly Associated with the Composition of Bifidobacteria in the Human Intestine.” Edited by Michael Otto. PLoS ONE 6 (5): e20113. https://doi.org/10.1371/journal.pone.0020113.
Wacklin, Pirjo, Jarno Tuimala, Janne Nikkilä, Sebastian Tims, Harri Mäkivuokko, Noora Alakulppi, Pia Laine, et al. 2014. “Faecal Microbiota Composition in Adults Is Associated with the FUT2 Gene Determining the Secretor Status.” Edited by Christopher Quince. PLoS ONE 9 (4): e94863. https://doi.org/10.1371/journal.pone.0094863.