You are what you eat- at least for your gut microbiome.

You are what you eat- at least for your gut microbiome.

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There has been some debate on how much our genetic make up (our genome) contributes to our microbiome.

The human microbiome is the full collection of genes of all the microbes that live on or within us. The human microbiome is composed of microorganism like bacteria and viruses. You might think "What! Bacteria and viruses! Yuk" but most of these microorganisms that make up our microbiome are not harmful, and in fact they help in the maintenance of a healthy body. The gut microbiome, for example, has many different bacterial species that co-exist with us and help us by producing metabolites, and also help digest our food.

Recently, human microbiome data has been a good predictor of many human conditions such as: diabetes, obesity, immune system function, and even our mental health.

A new paper published in the Journal Nature reports that the the gut microbiome is not significantly influenced by our genes but instead by our environment. Genetically unrelated individuals who live together are more likely to share similar composition of gut microbes.

We tend to forget that as humans we have our genome and the genome of all the microorganisms that co-exist with us: our microbiome. This brings up the question: What does it really mean to be “human”? This is because we are made up of more microorganisms than human cells! The famous 10:1 ratio of microbes to human cells has been debunked nonetheless, there are still more bacteria (39 trillion) than there are human cells (30 trillion), around 1.3 : 1 ratio. So we humans are more microbes than human cells.

I am a big fan of genetics, and we know our genes are important as they play a big part in who we are as humans. But, we must not forget about our other genome- the microbiome. This study reveals that , although we can't change our genes, we can change the composition of our gut microbiome by our environment, mainly by what we ingest (eg. drugs and food). This also serves as a great reminder that we must eat healthy to support good gut microbes, and in turn they will reward us by keeping us healthy.

Take care of your microbiome and it will take care of you.

Cheers!
Love Genetics
Ian

References:

Malan-Muller S. et al. (2018). The Gut Microbiome and Mental Health: Implications for Anxiety- and Trauma-Related Disorders. OMICS. 2018 Feb;22(2):90-107. doi: 10.1089/omi.2017.0077

Rothschild D. et al. (2018). Environment dominates over host genetics in shaping human gut microbiota. Nature. 2018 Feb 28. doi: 10.1038/nature25973.

Sender R. et al. (2016). Revised Estimates for the Number of Human and Bacteria Cells in the Body. PLoS Biol. 2016 Aug 19;14(8):e1002533. doi: 10.1371/journal.pbio.1002533.