We tend to think of stress eating as a negative thing, but what if the food you eat can actually help relieve stress and anxiety?
Hot on everyone’s lips in the world of science is the gut microbiome — or in non-science speak, the bacteria that live in your gut. The headlines claim you can beat stress with diet, thanks to your gut microbes. But unless you are a mouse, it may be wise to treat the latest news with some caution — for the moment at least.
The link between the brain and gut
A recent study from the APC Microbiome Institute in Ireland looked at how two prebiotics in our diet can affect the growth of gut bacteria linked to stress, mood and behaviour. But let’s start by explaining what a prebiotic is. It’s what the good bacteria in your gut love to feed on. And the type of food these bacteria love to eat is fibre, and lots of it.
Different foods contain different types of these prebiotics, so eating a range of foods can influence which bacteria are most active in the gut. In turn, the bacteria produce a raft of different substances, some of which are linked to lowering stress and anxiety. One such substance is serotonin, otherwise known as the ‘feel-good’ neurotransmitter. Serotonin isn’t just made in your brain. In fact, over half of the serotonin in your body is made in the intestinal tract. This fascinating connection between the gut and brain is now recognised by experts worldwide, with your gut being rightly called your ‘second brain’.
Keeping mice happy with prebiotics
In the new study, the research team fed mice two promising prebiotic ingredients called FOS (fructo-oligosaccharide) and GOS (galacto-oligosaccharide). Both FOS and GOS are non-digestible carbohydrates that reach the colon intact. It is here that they are fermented by the bacteria that live there. These prebiotics are found naturally in a range of foods that are high in fibre, such as green vegetables, legumes, beans and Jerusalem artichokes.
Healthy mice that were fed a combination of the two prebiotics had measurable improvements in anxiety, cognition and stress-related behaviours when exposed to stressful conditions. But, there was more going on below the surface. Gene expression changed in key parts of the brain also. Furthermore, prebiotic-fed mice had lower levels of stress-induced hormones.
So, depressed and anxious mice the world over are celebrating these research findings, but what to make of it for humans? The team is planning to run human trials to see if the same stress-reducing results can be replicated. But there is already a known link between diet and mental health. Recent research that was published in the American Journal of Public Health found levels of happiness and wellbeing go up for each extra daily serve of fruit and vegetables you eat.
Making sense of it all
Melding together the fields of prebiotics, probiotics and mental health creates a whole new research field: that of psychobiotics. Sounds pretty scary, right? Put simply, a psychobiotic is a live organism that, when eaten in adequate amounts, produces a health benefit in people suffering from psychiatric illness.
Having the right mix of prebiotics and probiotics in your diet may be one way to support your mental health. This new research presents a strong argument for targeting gut bacteria to address brain-gut mental disorders.
And the best thing about the research is that foods high in prebiotics are already what experts recommend that you eat lots more of for overall health. Improved mental health may be just one more benefit of having the right mix of gut microbes, to add to the list.