Mental Health Week 2020

foundation stone 2:

Diet, Emotion & Our Second Brain


From the 10th to the 17th of October it’s Mental Health Week and all week I shall be posting interesting little tips and hacks that are beneficial to our mental health.  Today’s is about the extraordinary influence our gut biome, the complex ecosystem of microorganisms that reside in our gut, has on our brain and mental well-being.  Discoveries are occurring at a rapid rate in this field.  Here I have presented just a small glimpse.

From the perspective of these new sciences our gut is often referred to as our second brain.  While our second brain is unlikely to appreciate philosophy or help us solve a cryptic crossword it is highly likely to be partly responsible for our mental energy, sense of wellbeing, anxiety levels and mood states.

So here are three fun facts about our second brain and some ways of taking care of it so it takes care of us:

  1. The first fun fact is that 90-95 percent of the body’s serotonin is to be found in the gut. 100 years ago a Russian scientist noted a type of endocrine cell called enterochromaffin cells, in the wall of the gut. It was only in recent decades we learned these cells directly connect to the neural system and to the brain.  These cells rely heavily on the micro-organisms that live in our gut which in turn rely on the food we ingest to carry on their important work.  As you might be aware, serotonin is a neurotransmitter referred to at times as the happy neurotransmitter.  One of its roles is to regulate mood and is strongly associated with well-being and contentment but also mood disorders such as major depressive disorder.  Foods that contribute to gut serotonin include diverse things such as oily fish, cheeses and eggs.  The great news is that chocolate is also a great contributor. 
  2. Speaking of the work of organisms our collection of gut flora, the gut biome, includes all the organisms such as bacteria, viruses and fungi that live, hopefully happily, in our gut. They are their own incredibly complex ecosystem. And just like every other ecosystem on the planet, this one requires all these microbes to live in balance and harmony.  In terms of ecosystem complexity ours is way up there.  A healthy gut is likely to contain trillions of microbes ranging across over 10 000 species, contribute 2-3 kgs to our body weight and contain more than 150 times the amount of DNA than the rest of our body cells combined.  Studies on mice have shown that major interferences in gut flora such as sterilisation have resulted in dramatic changes to memory, pattern recognition and other cognitive dysfunction as well as an inability to regulate and inhibit impulses, especially those impulses associated with risk aversion.  Whilst studies such as these can’t be ethically conducted on humans it’s not unreasonable to think the same might be true for us.
  3. Our gut contains more than 100 million neurones, which is why it gets the name “Second Brain”. This quantity of neurones is less than our main brain but more than our spinal cord and peripheral nervous system combined.   Not only is the gut rich with neurones, it also has a super highway of connection to our main brain otherwise known as the Vagus Nerve.  This huge neural pathway has always been thought to carry information from our brain to our gut.  And it does.  But this is only part of the story.  Studies are showing that 90 percent of the traffic is going the other way. That is, from our gut to our brain.   The neural connection from gut to brain is only partly understood and the race is on to understand it better but just the fact that it exists is highly suggestive of a yet to be discovered importance.

Here are three tips to good gut biome conservation.

  1. The first is eating a balanced diet that is high in unprocessed foods while keeping highly processed foods to a minimum.  Make sure you eat plenty of complex carbohydrates and good fats because these are “feel good foods”.  Foods high in soluble fibre such as strawberries, potatoes and oats are great choices.  Australians, on average eat 20 grams of fibre per day.  Our gut would love us more if we increased that to 40 grams.  Leaving skin on vegetables, choosing whole fruit instead of juice and opting for wholemeal and grains over processed foods all assist to reach the required amount
  2. Medications that are seeming quite harmless and are readily available can interfere with the delicate balance found in our gut biome. Antacids, readily available on the shelves in supermarkets are a good example of this.  Use of them once in a while is unlikely to cause problems but the regular need for them would be better addressed by a trip to your GP for advice.  The same goes for Panadol. It’s also timely to remind ourselves of the judicial use of antibiotics.  These drugs, for a whole host of reasons play havoc with our gut biome unsurprisingly and it’s refreshing to see much greater awareness of the risk of over prescription.  These are miracle drugs and have a critical role in treatment.  We need to reserve them for times when they are essential.
  1. The third and final gut health hack today is reduce and restrict our snacking. The human gut seems to have been evolved around feasting and fasting (perhaps our forebears called it famine). Over the millennia our clans would have struck it rich with food for a few days and they would eat like kings.  This would be followed by periods of food scarcity.  These days food is plentiful for the fortunate among us and most can eat when we want but it doesn’t mean that’s best for our well-being. Our gut likes to be rested periodically.  Consider having an early dinner followed next day by a late breakfast.  This allows our gut to take it easy for 12-14 hours.  Once or twice per week is achievable for most of us.

Hopefully this has got you thinking – and if you’ve got a gut feeling that all this is a good idea, you’re literally correct in all likelihood.

Murray Bardwell

Associate Lecturer, Rural Placement Education

Going Rural Health Ballarat

Mental Health Nurse & Clinician