Everyone knows that the brain is a very important, and enigmatic organ. Now the brain is kept separate from the entire body the blood-brain barrier, this barrier acts like a filter separating blood cells from the extracellular fluid in the brain (basically all cells sit in a lovely liquid called the extracellular fluid). This barrier is so selective that only water, some gases, glucose, some amino acids needed by the brain (these are the building blocks of proteins), and fat-soluble molecules can pass – and nothing else, not even antibodies (which are super important players in our immune system). It protects the brain from neurotoxins and common bacterial infections (although some nasties have their tricks).
Now, why am I going on about how special and selective the blood-brain barrier is? Intriguing research suggests that this highly impermeable membrane’s development is due in part to bacteria, and gut bacteria from the mother at that.
The fascination, however, goes a little deeper, you see every one of us has a whole host of micro-organisms thriving inside us, they technically make up 90% of ourselves – which are collectively known as the microbiome – are so crucial to our development as healthy human beings, and well we should really be both grateful and take care of these lovely germs.
In this study (Braniste et al. 2014) the development of the barrier was examined in germ-free mice (ones that are completely sterile – no bacteria AT ALL, they basically live in sterile conditions and even their food and water are germ-free, quite fascinating actually), and normal healthy mice, whose microbiomes were not interfered with. The study traced a certain antibody and found that in the normal mice the blood-brain barrier fused normally near the end of foetal development, and the antibody was restricted to blood vessels, whereas in the sterile mice, the antibody still continued to travel across into the brain.
Now what really clinches the deal here is that the germ-free mice who were then given a nice set of microbiomes had the permeability of the barrier decrease. Their results show that gut microbes communicate with the barrier not only during development but that this communication is propagated throughout the life cycle of the animal. Mothers, we thank you for your bacteria.
This also further strengthens the view that we are a product of the interaction between Our Genes and Our Environment, if our mothers were different, if their own environment was different it could have effects on us. So We really do have the Power, Mums are Super Heros and You, You are Awesome!