A plethora of research continues to show the links between the health of the gut and that of the brain. Kale Brock investigates.

Complementary health practitioners have drawn the link between our intestinal microbiota and overall health for some time, but only in the last decade have we really seen a big push from conventional medicine to solidify this theory with scientific evidence.

There is now scientific evidence supporting the importance of gut health to prevent both Alzheimer’s disease and depression.

Alzheimer’s disease is the most common form of dementia in the western world and comes at a severe cost to society, both economically and socially. A recent study published in the Scientific Reports journal reported researchers from Lund University in Sweden found a direct causal link between gut microbiota and the development of Alzheimer’s related damage in the brains of mice. In the study researchers took germ-free mice and inoculated them with gut microbes from mice who had Alzheimer’s. Interestingly, the recently inoculated mice began to develop signs of Alzheimer’s disease themselves, measured by testing levels of amyloid plaque buildup in the brain.

Deakin University recently released trial data showing for the first time that improving diet quality can treat major depression. This monumental study confirmed the connection between mental health and diet, something that has been talked about for years. With one million Australians currently living with depression, and a further two million living with anxiety, this study couldn’t have come at a better time.

Director of Deakin’s Food and Mood Centre Professor Felice Jacka said while the link between diet and depression was known for some time, this was the first randomised controlled trial to directly test whether improving diet quality can actually treat clinical depression.

In the three-month study adults with the major depressive disorder were split into groups and either assigned social support, or support from a clinical dietitian who prescribed food intakes reflective of the Mediterranean Diet; lots of vegetables, fruits, whole grains, legumes, fish, lean red meats, olive oil and nuts.

At the end of the trial, a third of those in the dietary support group met criteria for remission of major depression, compared to eight percent of those in the social support group.

“It also supports the previous extensive research from human population studies and animal research suggesting diet is a key determinant of mental and brain health,” Professor Jacka said.

The study suggests the new possibility of adding clinical dieticians to mental health care teams and making dietitian support available to those experiencing depression.

We can’t ignore the drastic rise in such neurological challenges in recent generations and, with mounting evidence pointing at the gut as a main player in this equation, dietary interventions that effectively modulate our gut microbiome will begin to receive much more attention as we move forward.

In my recent interview with Dr Margie Smith, who is a molecular geneticist specialising in the analysis of microbiome samples, she reiterated a whole foods diet is the healthiest diet to support the microbiome. In fact, this was a consistent message from the 16 experts I interviewed for my Healthy Gut Summit – that a whole foods approach is the perfect starting point to improve the health of the gut.

But how does a diet impact the brain? There are numerous theories and each come with solid scientific evidence. For instance, we hear regularly how our gut microbes are actually responsible for the manufacture of our brain’s most important chemicals – our neurotransmitters. However, this theory is receiving less attention now, as a new factor becomes illuminated by the intense scientific spotlight – inflammation.

Chronic inflammation can result in ‘leaky gut’ where the gut lining becomes ‘too leaky’ and allows macromolecules of food and pathogens into the bloodstream, subsequently causing an immune response within the body. Normally, the gut lining should let in micromolecules of food such as vitamins and minerals, which the body can use easily. Scientists now are theorising that it’s this chronic inflammation that can actually travel from the gut to the brain and cross the blood-brain barrier to negatively affect brain function.

Specifically, scientists have begun measuring levels of lipopolysaccharide (LPS), a toxic molecule made by bacteria in the gut, as an indicator of inflammation in the brain. Dr Perlmutter talks about this and cites studies where LPS is consistently correlated with neurological challenges such as depression and Alzheimer’s.

Kale’s top tips for improving your gut health
Regardless of the mechanistic functions of how these little microbes work on and inside of us, for you and me it comes down to this big question. How do we take such science and turn it into actionable health interventions in the home?

1. Commit to eating a wholefoods diet
2. Include lots of vegetables, fruits, whole grains, legumes, fish, lean red meats, olive oil and nuts.
3. Eat lots of colourful vegetables
4. Fruit and vegetables fall into five different colour categories: red, purple/blue, orange, green and white/brown. Each colour carries its own set of unique disease-fighting chemicals called phytochemicals. It is these phytochemicals that give fruits and vegetables their vibrant colour and some of their healthy properties.
5. Take a high-grade probiotic supplement Probiotics are live bacteria and yeasts that help balance your ‘good’ and ‘bad’ bacteria in your digestive system to keep your gut healthy.

Probiotics and prebiotics – friendly companions for your gut
Probiotics and prebiotics work together to help the growth of our body’s healthy bacteria and support healthy digestion.

Probiotics are types of ‘living’ friendly bacteria similar to those that inhabit our digestive tract. Probiotics allow more good microorganisms to enter your system and keep your gut well-balanced and smooth, replenishing the live cultures already there. Cultured or fermented foods such as yoghurt, buttermilk, aged cheese, sauerkraut, sourdough bread, miso, tempeh and kombucha are great sources of probiotics. Probiotic supplements can support the immune system and recovery after antibiotics.

Prebiotics are ‘non‐living’ food ingredients that reach the large intestine unaffected by digestion, and ‘feed’ the good bacteria in our gut helping them to grow and flourish. Prebiotics supplements are available and can also be found in legumes, rye, whole wheat products, artichokes, onions, cabbage, garlic and chicory root.

Synbiotics is the term used when probiotics and prebiotics are combined; it refers to the synergy of using them together to feed the human microbiome. The probiotics provide the live active bacteria and the prebiotics or soluble fibre provide the food for the probiotics survival.

The Gut Healing Protocol
Kale Brock’s Gut Healing Protocol focuses on healing the lining of the gastro-intestinal tract and provides a simple action plan with validated references to help you improve your gut health and overall vitality.

With nine years of research behind him, the health journalist and coach delves into one of the hottest topics in health science right now!

In this beautifully researched and presented book, Brock shares

• a scientific round-up of the gut and how it influences your health
• world expert views on the microbiome and the roles of various microbes
• why eliminating certain foods can drastically decrease gut inflammation
• how adding certain foods and supplements assists healing the gut lining
• a comprehensive, gentle eight-week program
• stunning, delicious recipes to help you heal your gut lining and rebalance your microbiome.