Each individual’s gut microbiome is a unique collection of trillions of microorganisms like bacteria and fungi that live in the gut, interacting with each other and the body in many different ways. Staff writer Florence Lakin discusses recent research into the impact this has on the body and the mind.
Heavily impacted by our diet, these organisms thrive on whole foods and plant fibres. Consuming an abundance of processed foods, sugars and additives can damage the microbiome and favour less beneficial microbes.
Having been investigated since as early as the 1800s, it has been shown to influence various aspects of our mental and physical health. We are now defining exactly what a healthy balance of microorganisms looks like and the depth of influence on the human body.
The gut microbiome is thought to have impacts on a wide range of bodily functions, from cholesterol levels to mental health, sleep and potentially even aspects of behaviour.
Professor Tim Spector, head of the department of Twin Research and Genetic Epidemiology at King’s College London, co-founded microbiome testing firm Zoe.
The firm recently ran the PREDICT programme, which collected microbiome data from over 34,000 people. Analysis identified 50 beneficial species which affect cholesterol levels, inflammation and immune health and body fat distribution, as well as blood sugar control.
It is believed that this occurs due to release of chemicals from the microorganisms in the gut. The study found that healthy participants had about 3.6 more of these advantageous species than people with a health condition and about 5.2 more than people with obesity.
A study was conducted in which rats were given faecal transplants from people with depression. These rats then seemed to develop depressive symptoms. Similarly, in preliminary trials, people who underwent depression treatment with faecal transplant had improved symptoms. This suggests that the composition of the microbiome could alter mood and mental state.
There is also emerging evidence to suggest that the bacteria living in the gut through childhood could influence personality. In another study, rats that were given faecal transplants from high-spirited toddlers were more willing to explore the environment around them than rats who had transplants from introverted toddlers. However, this could also be due to the outgoing toddlers trying a wider variety of food and hence developing a more varied gut microbiome.
Researchers have previously identified links between sleep conditions and the gut flora. A review of the studies comparing gut microbiota of people with and without sleep difficulties showed that the variety of bacteria was lower in those who had a sleep condition than those who didn’t.
Specifically, lower abundance of anti-inflammatory bacteria and higher abundance of pro inflammatory bacteria were found in people with insomnia, REM sleep disorders and obstructive sleep apnoea.
There is still much that is unknown about the gut microbiome, but ongoing research continues to further our understanding of its roles in the functioning of the human body.
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