We can try to ignore them all we like, but the facts are simply inescapable. One in four of us will experience a mental health problem this year. Take a second to let that sink in, one in four. When it comes to postnatal depression, the stats aren’t much better.
Fortunately, thanks to the growing number of initiatives aimed at increasing awareness and support for the millions of people suffering in silence, this baffling statistic has started to receive the attention it so rightfully deserves.
But what is it that’s causing these high rates of low mood, and what can we all do about it?
There are many factors thought to contribute to poor mental health, some of which are modifiable, such as physical activity, and others, which we can’t change, like our genetics. More recently, a new modifiable risk factor has been proposed, and believe it or not it’s the trillions of microbes that call our gut home (which scientists call our ‘gut microbiota’). Identification of this new, and somewhat unexpected, culprit has stemmed from some fascinating research that shows a two-way communication between our gut microbiota and our brain, commonly referred to as the gut-brain-axis.
So, what does the latest science say about the link between our gut microbiota and mental health? Of course, in research and science things are never straightforward, but there is growing evidence to support a role for our gut health in managing (alongside any necessary medications) mental health problems - and even to prevent them. To help explain a little more, there are three pieces to the gut-mental health-axis that I want to share…
Several studies have now shown that people with depression have different gut microbes to people without depression. But (and there is always a but) this type of research is called observational research which is rather weak in terms of scientific rigor. With observational research it’s a bit like the chicken and egg scenario; is it that people with depression are less likely to eat certain foods that feed specific bacteria, or could it be that specific bacteria are triggering depression? To help tackle this question we need to look at interventional studies.
A landmark probiotic study from 2017 randomised a group of pregnant mothers into two groups. One group received a specific probiotic (live beneficial bacteria) and the other group received a placebo (known as a fake probiotic) throughout their pregnancy and until their baby was six months old. At the end of the study, all the mothers had their mental health assessed and fascinatingly the mothers in the probiotic group reported a significantly lower depression score compared to the placebo group. Importantly both the mothers and researchers were blinded to the intervention, so didn’t know who received the actual probiotics verse placebo. Although incredible exciting, it wouldn’t be fair to over-hype this single study - it’s still early days for this research. Personally I do think there is hope for this idea of using probiotics to manage mental health, referred to as psychobiotics. However, I also think we need to be smarter and more specific with our choice of probiotic types - a one-size-fits-all model is very unlikely.
One of my favourite studies randomised people with moderate to severe depression to receive either gut-boosting dietary advice delivered by a dietitian for 12 weeks OR a type of counselling to act as the ‘placebo’ intervention (this was done to make sure that any benefit in the diet group wasn’t just because of the social interaction with the dietitian). What they found was really quite remarkable. Those following the Mediterranean diet had a MUCH greater improvement in happiness levels compared to placebo. In fact, over 30% of those in the Mediterranean diet group improved to a level deemed as no longer clinically depressed (using depression questionnaires), although it is important to note that many were still on baseline medications. Now, this particular study didn’t measure gut bacteria, but it’s well known that the Mediterranean dietary pattern has a positive impact on our bugs - raising the big question, could this benefit in happiness on the diet be due, at least in part, to an alteration in the gut-brain axis? Maybe.
In my new book ‘Eat Yourself Healthy’ I talk more about the gut:brain link along with practical strategies and easy recipes to help you to become healthier and happier from the inside out. I can’t wait to hear what you think.
Eat Yourself Healthy by Dr Megan Rossi is published by Penguin Life, Priced £16.99
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