There’s absolutely no doubt that a healthy gut is important for mental health. We’re still discovering the detail of the connection, but what we do know is that the relationship between the two is a strong one, and that together they form an integral part of the clockwork that keeps us happy, healthy and functioning well.
Happy Gut, Happy Head – What’s the Connection?
In the intricately folded tissue that lines the gastrointestinal tract are 200-600 million neurons. This is affectionately known as ‘the brain in our gut’ or ‘our second brain’. Messages are sent back and forth between our main brain and the brain in our gut, directly influencing mood and feelings of stress, anxiety and sadness, as well as memory, decision-making and learning. Our gut also stores 90-95% of the body’s serotonin, the neurochemical that is responsible for mood.
For some time now, the importance of the gut microbiome (the collection of good and bad bacteria and in our gut) has drawn immense interest from researchers who are keen to unravel their importance to mental health.
‘When you’re stressed you increase your chance of being depressed, and that’s been known for a long, long time. So the question that we wanted to ask is, does the microbiome participate in depression?’ – Alban Gaultier PhD, the UVA Department of Neuroscience and its Center for Brain Immunology and Glia.
Easing depression through the gut. The research.
New research from the University of Virginia School of Medicine has found that a diet that includes Lactobacillus, a probiotic bacteria found in yoghurt with live-cultures, could help to reverse the symptoms of depression.
The study was conducted in mice, but don’t let that take away from the importance of the findings. Mice are often used in these sort of experiments because of their various similiarities to humans, including biological and behavioural.
The researchers looked at the gut microbiome of the mice before they were stressed, and again after. There was a fascinating difference in the make-up of the gut microbiome before and after the mice were exposed to stress, with the mice showing a noticeable loss of Lactobacillus following their exposure to stress. Depression, or ‘despair behaviour’ emerged following the loss of Lactobacillus, but when the mice were given Lactobacillus with their food, they returned to almost normal.
‘A single strain of Lactobacillus is able to influence mood.’ – Alban Gaultier PhD.
How does Lactobaccilus make such a difference to mood?
The researchers explored further to try to understand how Lactobaccillus influences depression. They discovered that the levels of Lactobacillus in the gut affects a metabolite in the blood called kynurenine. This metabolite has been shown to drive depression. When Lactobacillus in the gut dropped, kynurenine increased. When kynurenine increased, and depression set in.
‘[Kynurenine is] something produced with inflammation that we know is connected to depression.’ – Ioana Marin, researcher.
Where to now?
The researchers are now intending to explore the relationship between Lactobacillus and depression in humans. Given the strength of their recent findings, they will see similar results in people as they did in the mice.
‘The big hope for this kind of research is that we won’t need to bother with complex drugs and side effects when we can just play with the microbiome. It would be magical just to change your diet, to change the bacteria you take and fix your health – and your mood.’ – Alban Gaultier PhD.
Further study is needed to understand the connection between Lactobacillus and depression in people. In the meantime, taking yoghurt with Lactobacillus won’t hurt, but it’s critical that if you are taking medication for depression, you don’t stop taking it without close consultation with a doctor.
The introduction of probiotics to has to happen slowly. Introducing large quantities of probiotics into your diet can lead to a worsening of symptoms because when probiotics kill off pathogens, they release toxins. It is these toxins that are likely to be already contributing to symptoms (depression, anxiety, physical illnesses), but when the release of toxins is suddenly increased (by the increase of probiotics), the symptoms may also increase. Go gently, and if you are unsure, talk to a pharmacist, doctor or naturopath for guidance.
And finally …
Depression is far too common. According to researchers, about 7 percent of people will experience a major depressive episode. This doesn’t take into account the people who have symptoms that aren’t at clinical levels, but which still cause some level of disruption to day to day life.
Depression is so much more than sadness. It steals feelings and leaves a heavy-hearted hopelessness in its place. It can be relentless like that. The medication available at the moment can be helpful, but not for everyone. Research has shown that many lifestyle factors that are healthy for all of us, such as meditation, social connection, exercise, and gut health can have a significant impact on the symptoms of depression. Although more research is needed to confirm the effect of Lactobacillus on depression, anything that won’t cause harm, but which has the potential to improve symptoms is certainly worth trying, and could actually make an important difference.