Gut Health - Our Second Brain

The term 'gut' refers to human intestines, although the term is often applied to the entire digestive-tract (gastrointestinal) that food and liquids travel through when swallowed, digested, absorbed, and leave the body as faeces.

The gut is an enteric nervous system that relies on the same type of neurons and neurotransmitters found in the central nervous system, so some medical experts call the gut our "second brain".

We each have a unique, lifelong relationship with our gut microbes, so the collective name given to the microbiota in an individual's gut is their "gut microbiome".

Dr Meagan Rossi, 'The Gut Health Doctor', insists that we should understand the "power and potential of the gut and how it influences - or even controls - so many systems in the body."

Dr Rossi observes that our gut microbiota (GM)... have three distinct ways of speaking to our other organs via:

• the immune system
• the nervous system
• the blood lymph circulation (which helps get rid of waste and toxins).

Dr Rossi points out in her article, Your Guide to a Happier, Healthier Gut (Body + Soul, 2022):

The Gut-Skin Axis - is a two way conversation going on between our microbes and our skin (just like with the brain). What we eat... often plays out on the [skin] surface. Our skin is an organ that relies on what we feed it to stay alive.

Foods that are filled with nutrients and phytochemicals that are good for our skin (vitamins A, C, E, and K; zinc, lutein, carotenoids, tocopherols and flavanols, chlorophyll, zeaxanthin and fatty acids) include:

• Green tea
• Dark chocolate (above 70% cocoa content)
• Walnuts
• Soy
• Tomatoes
• Citrus fruits
• Sweet potato
• Avocado

The Gut-Immune Axis - 70 per cent of our immune cells reside in the gut, alongside our GM. Gut microbes teach our system what's worth reacting to (disease causing microbes) and what's safe (like proteins found in certain foods).

The foods that nourish our gut-immune system (vitamins A, D, C, E, B6 and B12; folate, copper, iron, zinc, selenium, flavonoids, fibre, allicin, omega-3 and curcumin) include:

• Walnuts
• Garlic
• Sun exposed mushrooms (boosts vitamin D content)
• Carrots
• Oranges
• Firm tofu
• Chia seeds
• Turmeric
• Broccoli

The Gut-Hormone Axis- the gut plays a role in regulating hormones - from the thyroid to appetite and sex hormones

Foods to support our hormonal balance (phytoestrogens, calcium, zinc, magnesium, fibre, folate, iron, unsaturated fats and protein) include:

• Cinnamon
• Almonds
• Cauliflower
• Brussel sprouts
• Fermented dairy
• Quinoa
• Bananas
• Dark green leafy vegetables

The Gut-Metabolism Axis - the chemicals our gut microbes make when they digest fibre from plants can impact our appetite.

These chemicals, such as short-chain fatty acids, tell our body we've had enough. In turn, his halts production of hunger hormones such as ghrelin, and increases the "I'm full" hormones such as leptin.
(Dr M. Rossi 2022)

Foods that support the gut-metabolism axis (fibre including resistant starch, beta-glucan and prebiotics) include:

• Natural live yoghurt
• Oats (jumbo oats best - more of the whole oat retained than 'porridge' rolled oats)
• Balsamic vinegar
• Ginger
• Cold potato salad
• Butter beans
• Pistachios
• Chilli peppers
• Grapefruit

Dr Rossi maintains that a plant-based diet is the foundation of a well-fed gut and has benefits for everything from our immunity to our mood.
(from Dr Megan Rossi. Eat More, Live Well. Penguin 2022; and Your Guide to a Happier, Healthier Gut. Body + Soul 2022):

More Foods for Gut Health

• Kefir - a cow or goat's milk drink fermented with Kefir grain. It originates from Eastern Europe and South-west Asia. The name derives from the Turkish word 'keyif', meaning 'to feel good after eating'.
• Miso - a thick paste produced by fermenting soybeans with salt and kōji (Aspergillus oryzae fungus).
  Miso is a traditional Japanese seasoning used for sauces and spreads, pickling vegetables, fish or meats and mixing with dashi soup stock to serve as miso soup.
• Sauerkraut - is finely cut raw cabbage that has been fermented by various lactic acid bacteria.
  It is one of the best-known national dishes in Germany and widely consumed in Eastern Europe including Ukraine, where it is known as kistla kapusta (sour cabbage).
• Kimchi - a traditional Korean side dish of salted and fermented vegetables, such as napa cabbage and Korean radish.
  A staple food in Korean cuisine, it is eaten as a side dish with almost every Korean meal and also used in a variety of soups and stews.
• Sourdough - sourdough bread is leavened with Lactobacillus bacteria and wild yeasts compared to regular bread which is leavened with packaged yeast.
  This mixture of bacteria and wild yeast is called a sourdough starter. The starter is made by mixing flour and water and letting it sit until microbes ferment it.
  Sourdough is more nutritious, easier to digest and has a lower glycaemic index and contains less gluten than other breads.
• Olive oil - is a liquid fat obtained from olives, the fruit of Olea europaea tree. Olive trees have been grown on lands around the Mediterranean Sea since the 8th millennium BC.
  Olive oil is produced by pressing whole olives and extracting the oil from the fruit. It is commonly used in cooking or as a salad dressing.
  High quality extra-virgin olive oil (low free acidity content) has greater resistance to oxidation than most other cooking oils, as a result of its antioxidant and mono-unsaturated fat content.
• A2 milk - cow's milk is considered a 'super food'; however, it can cause unpleasant gastro-intestinal symptoms in some people who are lactose intolerant. Lactose intolerance tends to occur as we age with lactose being the main sugar in cow's milk.
  Plant-based 'milks' are generally lower in protein and the nutrients found in dairy milk (calcium, phosphorous, riboflavin, Vitamin B12).
  There are 2 types of beta-casein protein in regular cow's milk, A1 and A2.
  A1 beta-casein may contribute to symptoms of digestive discomfort. A2 is free of lactose and therefore A2 milk is less likely to negatively affect those with lactose intolerance, yet still provide the same protein and nutritional value of regular cow's milk.

Out of Balance

In her article, What's messing with your gut health?, Jaymie Hooper uncovers everyday habits that can throw our gut health out of balance.

1. Fad Diets

Restrictive food diets, such as detox-diets, are unsustainable over the long term and can 'wreak havoc on your gut'. And carb-cutting eating plans such as the keto diet deprive your microbiome of essential fibre.

Depriving our gut bacteria of nourishing fibre-rich vegetables, fruit, wholegrains, cereals, nuts, seeds and legumes starves the gut microbiota and they begin to eat away at our gut lining which can lead to inflammation in the body.

Fermented foods such as kimchi and kombucha can also help balance our GM.

2. Over-Exercising

Exercise is beneficial to gut health by increasing microbial diversity. However, a Monash University research study has revealed that excessive exercise of 2 hours or more may injure the cells of the intestine and make it more likely to develop gut issues.

When planning your exercise, make sure you adequately hydrate and fuel your workout with healthy carbs.

3. Keeping It (too) Clean

Modern household cleaners can alter your microbiome. According to Canadian researchers, children who are exposed to disinfectants (multi-surface cleaners) at least twice a week have an imbalance of gut bacteria, which may lead to obesity.

However, eco-friendly cleaners and home-made surface cleaning products with natural ingredients -such as one part vinegar, one part water and drops of lemon essential oil - had no negative effect on gut balance.

4. Lack of Sleep

Poor quality sleep and lack of sleep can negatively impact gut health. Recent US studies revealed those who have a good night's sleep have more diverse gut microbiome compared to those who have trouble sleeping.

5. High Stress Levels

Stress can upset the balance of the gut leading to gastric symptoms such as irritable bowel syndrome. Chronic stress may also significantly alter the composition of gut microbiota that can cause negative behaviour and physiological changes.

(adapted from J. Hooper.Body + Soul, 2022)

Sweeteners

The war on sugar has been raging for more than 50 years and shows no signs of slowing down... Excessive consumption of the white stuff can lead to everything from tooth decay and energy crashes to inflammation, weight gain and an increased risk of heart disease.

(J. Hooper. Sweeteners 101. Body + Soul. Herald-Sun, 2022)

Compared to sugar, most sweeteners contain zero calories and are 200 to 600 times sweeter than sugar. These alternatives to sugar can be found in certain 'sugar-free' drinks, protein bars and chocolate.

Natural and artificial sweeteners that nutritionists have examined reveal the following impacts on our health, including our gut microbiome:

Aspartame

A widely used sweetener sold as NutraSweet and Equal. It is 200 times sweeter than table sugar and found in low-calorie processed foods and soft drinks. Also used as a table-top sweetener for hot drinks, reports show that it may cause headaches and migraines.

It is not suitable for baking because it loses its sweetness at high temperatures.

Dr Rossi reports that in animal studies, Aspartame aggravates certain gut bacteria, making them more aggressive.

Sucralose

Derived from sugar but through chemical restructuring it is 600 times sweeter than sugar. It can be found in lollies and chewing gums.

Also known as Splenda, it is free of calories and stable under extremely high and low temperatures, making it suitable for baking and for use in low sugar ice-cream.

Studies have revealed that Sucralose can negatively impact gut microbiome that may lead to inflammation.

Xylitol

A sugar alcohol that is sweeter than sugar with fewer calories. Known to cause digestive disturbances in some people and highly toxic to dogs.

Xylitol may be beneficial to dental health as it inhibits growth of bacteria and plaque.

It is digested at a slower rate and not completely absorbed and so may be a better choice for people with diabetes.

Polysorbate-80

Anon-ionicsurfactant and emulsifier that is often used in pharmaceuticals, foods and cosmetics. It can be used in ice-cream to make it smoother and to increase its resistance to melting.

Polysorbate-80has been shown to inhibit the growth of certain beneficial anti-inflammatory gut bacteria such as bifidobacteria.

Stevia

Stevia is extracted from the leaves of the plant Stevia rebaudiana, a shrub common in Paraguay. The Stevia leaf is sweeter than sugar but contains no calories.

Stevia is stable enough to be used in foods, liquids and baking as a replacement for sugar.

When metabolised Stevia passes mostly unchanged through the body to the colon. Nutritionist, Catherine Saxelby maintains "it's therefore viewed as more 'natural' with fewer side effects than other sweeteners".

Erythritol

A sugar alcohol that acts as a sweetener, humectant (keeps food moist) and to enhance texture.Commercially produced Erythritol is low in calories and has "a clean sweet taste".

It is found in some fruits, mushrooms and fermentation foods such as soy sauce and wine. Low in calories, Saxelby suggests, "it is rapidly absorbed by the small intestine and then rapidly eliminated... you're unlikely to have any of the laxative side effects associated with excessive consumption."

(adapted from J. Hooper. Sweeteners 101. Body + Soul, 2022;and Dr M. Rossi. Your Guide to a Happier, Healthier Gut. Body + Soul, 2022)

Bush Tucker

Evidence suggests that Aboriginal people were healthy before European settlement and did not suffer from chronic lifestyle and nutrition related diseases.

A rapid transition from a well-balanced, varied and nutrient dense diet to a diet today, which is energy dense, high in saturated fat and sugar has brought about a significant health transition.

Aboriginal people in remote regions of Australia suffer higher rates of lifestyle and nutrition related diseases than any other Australians.

(C. Bussey. Food security and traditional foods in remote Aboriginal communities.Australian Indigenous Health Bulletin. Vol 13 No 2, April 2013 - June 2013)

Arts, travel and lifestyle writer, Patricia Maunder maintains, 'There are about 6000 recorded types of native Australian foods. But most of what we often call "bush tucker" has long been regarded as a novelty or restaurant luxury.'

...however, that's starting to change . Plants and animals that have sustained Australia's Indigenous people for tens of thousands of years are being more widely embraced, not just for their unique, exciting flavours, but also for their nutritional value and sustainability.

(P. Maunder. Help Yourself.The House of Wellness, 2022)

refer BUSH TUCKER The Kakadu Plum - case study

Researched, compiled, composed, written and edited by Dr Steve Gration, December 2022.

References and Sources

C. Bussey. Food security and traditional foods in remote Aboriginal communities. Australian Indigenous Health Bulletin. Vol 13 No 2, April 2013 - June 2013.

Hooper, Jaymie. Sweeteners 101. Body + Soul. Herald-Sun, 30 May 2022.

Hooper, Jaymie.What's messing with your gut health? Body + Soul. Herald-Sun, 29 September 2022.

Maunder, Patricia. Help Yourself. Wellness + Nutrition. The House of Wellness. Herald-Sun, 20 March 2022.

Orloff, Judith. Thriving as an Empath 2019.

Rossi, Dr Megan.Your Guide to a Happier, Healthier Gut. Body + Soul. Herald-Sun, 14 March 2022.

Rossi, Dr Megan. Eat More, Live Well. Penguin, London 2022.