My 3rd genome!?

My 3rd genome!?

Margie GanderApr 15, '19

You may still be getting your head around all the information available on personalised genomics and might not be ready to think about a 2nd or 3rd genome! I completely get that BUT if you really want to be optimally well then understanding yourself as a "meta-organism" will get you there faster. 

You may also have noticed that people are talking more and more about mitochondrial health. You may also wonder what does this mean and why you should be taking notice of these little, bug-shaped powerhouses? In short, they are your third genome (coming after your GUT genome and of course your nuclear genome) so as part of this perfect triad, it's worth taking a deeper look. 

What are mitochondria? 

Mitochondria are organelles that act like a digestive system inside your cells. They sit next door to the nucleus in each cell and act as good neighbours should, being very helpful in making the cell function well. They take in nutrients, break them down, and create energy for the cell in the form of ATP energy. They have their own DNA structure, meaning that there is significant interplay between your nuclear genome and you mitochondrial genome. Just so that we are clear, your nuclear genome is your entire DNA inheritance from your biological parents whereas your mitochondrial genome is a single chromosome passed onto you by your mother. It is the interface between the two of these is where we are going to focus to determine your mitochondrial health and how you can prevent diseases associated with mitochondrial dysfunction.

It is also good to know that as many mitochondria that your mom had when she gave birth to you, is the number of mitochondria you would have inherited. However, you can increase the number of mitochondria by exercising and feeding them the correct nutrients. This is incredible! 

So what are the 3 genomes in my body?

Research by P. Garagnani et al. in 2014, explains that we need to be aware of the "cross-talk" between our nuclear DNA, mitochondrial DNA, and GUT microbiome DNA in order to truly understand wellness, anti-ageing, and longevity. 

To make thing easier, I use this table to illustrate this concept:

Nuclear DNA  Mitochondrial DNA GUT Microbiome
Heritability  inherited from both parents inherited from your mother only vertically inherited from both parents + the environment
  • long, open-ended
  • 46 chromosomes containing 3 billion nucleotides
  • 20 000 - 25 000 genes
  • short, circular
  • 1 chromosome
  • 37 genes
  • 500 species each with their own genome
Function Phenotype, hard wiring for traits as well as over a billion biochemical actions daily Encodes a specific group of proteins involved in the energy function Supports healthy digestion, immunity, and neuro/brain function 


In trying to achieve optimal health and/or prevent lifestyle, related chronic disease, you need to have a handle on all three of these. A great place to start is to do some testing. Gaining insight into your unique functioning will take the guesswork out of your mitochondrial health choices. 

What are the symptoms of mitochondrial dysfunction?

Mitochondrial disorders may be caused by mutations (acquired or inherited), in mitochondrial DNA or in nuclear genes that code for mitochondrial components. Mitochondrial dysfunction can also be acquired over time due to environmental exposures, poor diet, certain medications and/or viruses. 

The cells of the brain, liver, and muscles are among those that require a lot of energy, so they have a high number of mitochondria to support these energy needs. When mitochondria aren’t working well, these are often the parts of the body to show signs of poor function. When mitochondria are not functioning well then we start to see the development of the following:

  • Autism
  • Bipolar disorder
  • Schizophrenia
  • Depression
  • Diabetes
  • Parkinson’s disease
  • Asthma
  • Chronic fatigue syndrome
  • Alzheimer’s disease
  • A variety of gastrointestinal disorders

The interface between my genome and the mitogenome

I think that it is important to repeat the difference between your own genome (i.e. your nuclear genome) and the mitochondria's genome and understand the relationship between the two within your cells. 

More than 90% of the factors required for mitochondrial function are encoded by the nuclear genome. The interaction between these two genomes is bidirectional, meaning that there is both a flow of information from the nucleus towards the mitochondria and back.

To date, it is well known that the balance of the crosstalk between the nuclear DNA and the mitochondrial DNA is essential for cellular balance and events that upset this delicate equilibrium increases the vulnerability of the cell and as a result can increase the rate of ageing.

What is so exciting about anti-ageing medicine and genomics is the focus on specific genes located in the nuclear DNA that may affect the communication between these genomes.

Under normal conditions, damaged mitochondria are removed via autophagy (that's why I love the ketogenic diet and intermittent fasting so much!)  but during ageing autophagy declines, leading to accumulation of dysfunctional mitochondria. 

This table is useful in helping you to identify your genotype for mitochondrial dysfunction. I call this the "mitochondrial genotype". 

Gene  Function  Support
The MnSOD or SOD2 gene is vital for antioxidant activity within the cell, especially within the mitochondria. It encodes the genetic pathway responsible for scavenging 'oxidants' (free radicals) and protects cells against oxidative stress.
Reduce your exposure to environmental toxins and stress. Increase your phytonutrient and 
glutathione intake.
This gene is responsible for respiratory capacity and the rate of energy production during exercise. This protein is also important in the formation of new mitochondria: the ‘powerhouse’ of the cell where energy is produced.
A ketogenic or Mito-food diet is ideal to support this genetic pathway. Supplementation with mitovive can assist. 
Sometimes called the master regulator of mitochondria, PPARGC1A is also involved in the exercise-induced increase in mitochondria.
Managing an ideal weight and doing regular exercise is critical. 
UCP1 is mainly expressed in brown adipose tissue and has a central function in thermogenesis and energy homeostasis, as well as reducing the production of reactive oxygen species in the mitochondria. Under certain pathological conditions, such as hyperglycemia, UCP1 has been found to also be expressed in skeletal muscle, white adipose tissue, retinal cells, and pancreatic beta cells.
HIIT training, weight management, and a ketogenic diet can support the activity of this gene. 


To find out more about adopting the Mito-food diet and how to boost your mitochondria, book a functional medicine health coaching session below: 



In summary, healthy mitochondrial function and crosstalk with your other genomes means wonderful, natural energy. It would seem that there is more to that daily 11 am and 4 pm energy-slump, coffee and sugar grabbing moments than you may have originally thought!

Written by:
Marguerite Doig-Gander
BA (Speech, Hearing & Lang Therapy) Hons | FMCHC | ReCODE Coach 

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