Imagine a web of communication (some of it wireless) between all our cells. Microbes are the key link in this communication.
A significant proportion of the calories we eat don’t get absorbed into the bloodstream for use by our bodies. Instead, the food is eaten by the microbes further down in our colon. As the microbes eat the food they produce waste products. The waste products are important communication molecules.
Initially, the waste products give signals to our gut lining cells and gut immune cells, starting the conversation, if you like. Thereafter, some of them may get absorbed into our bloodstream and continue the ‘conversation’ anywhere in our body. This can be good or bad, depending on the microbes and what messages they are sending.
The beneficial microbes make helpful communication molecules like short chain fatty acids and vitamins which keep us healthy. Unhelpful and pathogenic microbes produce toxins called Lipopolysaccharides (LPS) and others, and inflammatory signalling molecules that can contribute to disease processes like high blood pressure, diabetes and other inflammatory conditions.
Butyrate is another communication molecule made by our beneficial gut bacteria. It is essential for gut health, immune health and brain health. Butyrate helps to prevent cancer, speed our metabolism and reduce inflammation – which is key to good health. We can measure our levels of butyrate in a stool sample. Please contact me if you would like me to arrange a stool test for you – it’s easier than you think and can be done alone at home and sent in the post. If low, you will know to focus on feeding the butyrate-producing bacteria to reduce inflammation and improve health.
There are other messenger molecules too. The gut microbes, together with our gut cells, make neurotransmitters. Neurotransmitters are chemical molecules which allow nerves to pass their messages from one nerve to another throughout the body.
Serotonin is a neurotransmitter made in large quantities in the gut. Serotonin helps to make us happy and helps us to sleep well. We need to keep our gut healthy so that we can make enough of this happy hormone.
Gamma-Aminobutyric Acid(GABA) is another neurotransmitter produced by our gut microbes. GABA helps to keep us calm. It balances stress neurotransmitters like cortisol. Acetylcholine, histamine, melatonin are other important chemicals produced in the gut to enable the body’s cells to communicate with each other.
In addition to these chemical messenger molecules, we also have physical lines of communication. We have millions of nerves that connect our gut and brain, and its been called the “gut-brain axis”. The vagus nerve is one of the biggest nerves that connects our gut to our brain. It sends signals both ways. For example, if you are stressed, not only does the brain send distress signals to the gut reducing the digestive process, but the gut bacteria then communicate back to the brain, via the vagus nerve, telling it what’s happening down in the gut and what to do about it.
And finally, a very important gut-brain connection is through our immune system. This is a huge and complex system of communication. One important thing to know is that together our gut immune cells and our microbes control the levels of inflammation in our body and this is believed to be key in helping to prevent degenerative diseases like cardiovascular disease, metabolic syndrome, diabetes and dementia.
We’re half way, that was Part 5, and we have another 5 still to come.
I hope you are enjoying this series and learning something useful from all of this. Look out for Part 6 tomorrow when we will take a look at your microbiome and links to different diseases – important stuff!