Your gut is connected to your brain, and here's an example why
There's a lot of talk about MTHFR and COMT gene these days, but another gene that is getting alot of attention is the FUT2 gene. This is another gene that proves the connection between your gut and your brain health, as the different phenotypes for this gene will determine the type of gut microbiota that you will have. As many of us are starting to be aware of the importance of our gut health, more and more studies are trying to demonstrate how it impacts our health longevity.
Let me start off first by letting you know that there is no "good" or "bad" phenotype, much like there are no "good" or "bad" exercises, having a certain type of gene only allows you to understand whether your life style choices suits your body (the same way as certain type of exercises may or may not suit your life style choices). The reason these genes, including MTHFT, COMT, and FUT2, are getting more attention than any other genes (even though they are all important), is because of the array of affects it has on our bodily system. FUT2 gene is just ONE example of how the gut can affect our health.
To understand what FUT2 gene does, I'll need to talk about blood type first. So we all know that the general population are designated with ABO blood group, which really doesn't mean much other than in the world of blood transfusion, and some sort of self identity. In a more sophisticated way of looking at blood types, it basically tells us the type of antigens (antibody generators) we have in our system. Antigen is a very confusing way of describing the type of sugars and protein that are present in our cells. All ABO blood group requires an H antigen, you can think of this H antigen as the pre-requisite of having ANY blood type, this H antigen is made up of fucose and galactose (which are different types of sugars). For people with type O blood, they possess the H antigen, which is the precursor form of A and B antigen, but do not possess A or B antigens. As you can imagine, type A and type B will then possess antigen A or antigen B, respectively. Those who do not possess the H antigen, will not have any designated blood type and are called Bombay blood type, which means they cannot receive blood from any of the ABO blood type groups, and can only receive blood from other Bombay blood type.
The most important thing to take away from blood groups, is that they are basically made up of different antigen aka, different types of sugar, and our genes is what determines what kind of sugar we will possess in our red blood cells (FUT1 gene). So what does FUT2 gene do? Much like our red blood cells, many other parts of our body also "express" our blood type, meaning that our unique ability of our cells to bind to different types of sugar is also present in many other parts of the cells in our body. Next to our blood, our digestive system (especially the small intestine), our thyroid gland, adrenal gland, reproductive system (especially the ovaries), kidneys, pancreas and lungs shows expression of these antigens in order from highest to lowest. FUT2 gene is what determines the presence of H antigen (again, the same type of sugar seen that make up the H antigen in blood groups) in the cells that lines the small intestine and bodily fluids. Depending on whether they have the presence of H antigen in the cells of small intestine and bodily fluids, they will be called either "secretors" or "non-secretors". If they have an active FUT2 gene, they will be able to make the enzyme necessary to produce H antigen and hence will be present in the cells of the small intestine and bodily fluids, hence, "secretors" (because...they secret cells that possess H antigen). If they have a relatively low activity or no activity in FUT2 gene, they will NOT be able to demonstrate H antigen in the cell present in small intestine and bodily fluid, hence, "non-secretors". Let me explain FUT2 genes relevance in 2 different ways:
1. People with an active FUT2
2. People with an inactive FUT2