A ‘gut feeling’ can help your brain
Research finds a link between good cognitive health and eating more fruit.
Key facts on the microbiome
Your microbiome is a collection of many millions of different microorganisms naturally living in and outside your body.
You have microbiomes in your gastrointestinal tract (your “gut”), skin, and other parts of your body.
Your gut microbiome helps with many body processes; for example, digesting some sugars that your body cannot breakdown and supporting your immune system.
Illness, some antibiotics, an unhealthy diet, your age, and genetics can disturb the balance of your microbiome, which can negatively affect your health.
You can improve your gut health by eating a varied plant-based diet, eating fermented foods, avoiding highly processed foods, exercising regularly, and getting enough sleep.
Your gut is responsible for breaking down the food that you eat as well as absorbing the nutrients your body needs to function. The gut is also vital to the functioning of your immune system.
What’s more, world leading Australia-China research suggests a healthy gut also leads to a healthy brain and prevents dementia.
The study – the first in humans after positive results in animal studies – found that people with reduced gut microbiota (see key facts below) were more likely to be cognitively impaired.
The study looked at 229 adults aged 60 years and over from Shenzhen, China. They were divided into cognitive impairment and no cognitive impairment groups. They then had their gut microbiota characterised.
The researchers found that men with cognitive impairment had a much lower diversity of gut microbiota compared to men who were cognitively healthy.
The researchers found that gram negative bacteria – which facilitate the production of amyloids associated with the development and progress of Alzheimer’s Disease – were more prevalent in men with cognitive impairment.
The good news is that the study also found that increased fruit intake and exercise contribute to a higher abundance of at least three “good” bacteria – Megamonas, Blautia, and Veillonella – linked to cognitive health.
With an ageing population, the number of people with dementia globally is expected to reach 78 million by 2030. According to Professor Zhang, the human gut microbiome is “often referred to as the body’s second genome because of its role in shaping intestinal health and overall energy and immunity.”
“Our findings reveal that consuming fresh fruit and engaging in regular exercise help promote the growth of gut microbiota, which is beneficial for cognitive function and can protect against cognitive impairment,” he said.
People with chronic illnesses such as psoriatic arthritis, type 1 diabetes, type 2 diabetes, atopic eczema, coeliac disease, obesity, and arterial stiffness have a less diverse range of bacteria in their gut than people without these diseases. The exact role of the gut microbiome in these diseases is not yet clear, and research is ongoing.
There are also links between gut health and mental health problems such as anxiety and depression.
Factors include:
Stress
Illness
Being overweight
Overuse of antibiotics
Eating a poor-quality diet.
Normally your gut has a special barrier that lets nutrients in but stops bacteria and other harmful substances from entering the bloodstream.
But these barriers can become “leakier”, allowing bacteria and molecules into the bloodstream that shouldn’t be there.
Diseases such as inflammatory bowel disease, coeliac disease, and peptic ulcer disease have major impacts on your gut health and general physical health.
It’s important to consult your doctor. General advice includes:
Diet
Make sure you eat a wide variety of plant-based foods, including vegetables, fruit, beans and legumes, and whole grains. These foods contain vitamins, minerals, and other elements that are essential for good health. They also contain fibres, known as prebiotics, which are not themselves digestible, but encourage and promote the growth of “good bacteria” in the gut.
Fermented food is also good. Fermented foods are foods where the sugar content has been broken down by bacteria or yeast. Fermented foods are high in probiotics, which are good bacteria that are beneficial for your gut. These include yoghurt, kimchi, sauerkraut, kombucha, miso, and sourdough.
It is best to avoid foods that can be harmful to gut health, including highly processed foods and foods containing high levels of sugar, salt, and saturated fats.
Supplements
Probiotic supplements contain good bacteria and yeasts. Probiotics can help balance the gut microbiome, especially in people whose gut microbiome has been impacted by antibiotics, other medicines, special diets, or disease.
Lifestyle
Gut health is also influenced by physical activity, stress, sleep, antibiotic use and other lifestyle and environmental factors. It is important that you manage your stress, stay physically active, and ensure that you get enough sleep.
Note: Always consult a qualified medical professional before making changes to your diet and fitness regime.
Related reading: Monash, The Australian, Health Direct
