Great Health Guide


Gut bacteria produce feel-good hormones which influence the central nervous system

- Dr Jenny Brockis

Who decides what you eat at each meal? Is it your kids, or do you have the power over what goes in the shopping trolley? It turns out our food choices are influenced by our microbiome, the 100 trillion or so bacteria, viruses, parasites and fungi that inhabit our guts which are primarily concerned with their survival and welfare. This symbiotic relationsh­ip is as old as we are and influences us across our life span.

It’s only recently that scientists joined the dots to better understand how our brain, the gut’s enteric nervous system and microbiome communicat­e with each other. Our gut microbes not only decide what’s for dinner, they influence the immune system, the level of inflammati­on in the body, your health, mood, memory and cognition. There are between one and 5000 different species of bacteria in our gut, either commensals that keep us healthy or pathogens linked to disease.


The communicat­ion channel linking the brain, the enteric system and the microbiome is the bi-directiona­l vagus nerve with 80% of the traffic heading towards the brain and 20% to the gut.

Our gut microbes manufactur­e hormones and neurotrans­mitters identical to those produced by humans, including dopamine, serotonin, gamma-aminobutyr­ic acid (GABA) and noradrenal­in that influence the central nervous system. They also convert carbohydra­tes into short chain fatty acids, important for strengthen­ing the bloodbrain barrier, to protect the brain from infection and inflammati­on.


Tuning in to what your gut is telling you helps better decision making. A high vagal tone means it’s safe to proceed, putting you in a cool, calm and collected state. A low tone is a warning signal that something isn’t quite right, like when walking down a dark pathway at night.


We are what we eat and a high fat, high sugar diet is depressing.

The Smiles trial run by Felice Jacka and her team was a world first showing how dietary interventi­on had a positive associatio­n on reducing depressive symptoms. Other

research has found two specific types of dopamine producing bacteria (dopamine is part of the brain’s reward circuitry) is lower in individual­s with depression.

Ted Dinan from the APC Microbiome Institute, believes the Psychobiot­ic Revolution heralds a seismic shift in our understand­ing of how the body and mind work together. Balance is what matters, knowing what keeps your commensals healthy and the pathogens at bay, for better health and cognition.


Mum was right. Eating a wide variety of vegetables especially leafy greens and following essentiall­y a plant-based diet is best.

2. Eat like a Hazda.

Diversity rules. The Hazda from Tanzania have one of the most diverse microbiome­s on the planet, around 40% higher than the average American and 30% higher than the average Briton. Their diet is highly protective as they have virtually none of the Western diseases of obesity, heart disease, cancer or allergies.

3. Add more fibrous foods.

These are the prebiotics that feed your healthy commensals. Think green bananas, onions, garlic, leeks, Jerusalem artichokes, sweet corn, chickpeas, other beans, lentils and cashews. Aim for 40 grams of fiber a day, many of us eat less than half that.

4. Add more probiotics.

These are the fermented foods high in living commensals including yoghurt, kefir, kombucha, miso, kimchi, soybean products and pickled herring. While

there are many probiotic supplement­s available, their effectiven­ess remains in doubt. Eating real food is the best way.

5. Eat less processed and junk food.

Food manufactur­ers have mastered the art of producing highly processed food that is calorie dense and nutrient poor. It’s often high in fat, sugar and salt, and detrimenta­l to a healthy biome.

6. Cut the sugar.

The easiest way is to reduce the amount of soft drinks that you consume and drink more water, with a slice of lemon if preferred. Switching to artificial sweeteners such as aspartame, saccharine or sucralose is not recommende­d as these have been shown to be toxic to our gut microbes and reduce microbial diversity. Please note, that natural sugars as found in fruits and vegetables are NOT a problem. It’s about avoiding the added refined sugar found in processed foods.

7. Consider the flexitaria­n option.

There is an abundance of evidence supporting that a predominan­tly plantbased diet is the best way to support a healthy diverse microbiota. There is no need to become vegetarian or vegan unless you wish to. A flexitaria­n approach consuming more vegetables and less meat is a good compromise.

Dr Jenny Brockis is a Medical Practition­er and Board-Certified Lifestyle Physician specialisi­ng in brain health and mental performanc­e. Jenny’s approach to overcoming life’s challenges is based on practical neuroscien­ce which enables people to understand their thoughts and actions leading to effective behavioura­l change. Jenny is the author of Smarter,

Sharper Thinking (Wiley) and may be contacted via her website.

 ??  ??

Newspapers in English

Newspapers from Australia