Could prebiotics be the secret to a better mood?

We know there is a strong link between our gut and our brain and there is a growing body of evidence to back this up. Specifically, research has shown that the population of microbes (bacteria, fungi, viruses) that inhabit our gut can directly affect our mood…positively and negatively.

There are a number of factors that can influence the health of our gut and the makeup of the bugs that live there. Stress, poor sleep, lack of exercise, toxins and medications can all play a role, but what we eat is one of the factors that can have the biggest impact on our gut bugs and therefore our mood.

Most of us have heard about probiotics and have some awareness of the benefits they may have on gut health, but are we as familiar with prebiotics?

Probiotics, found in fermented foods and drinks such as live yoghurt, sauerkraut, miso and kombucha, contain live ‘good’ bacteria. The idea is that by eating these (or taking probiotic supplements), it will help to populate our guts with the beneficial bacteria found in them.

There is still some debate about the effectiveness of probiotics as some foods and supplements only contain a single strain, some can be quite transient so don’t get chance to flourish, and there’s also a question mark as to whether they actually make it through the acidic environment of our stomach and into our intestines in tact.

What exactly are prebiotics?

Prebiotics on the other hand provide food for the beneficial bacteria that are already in our gut. By supplying them with the right fuel, they promote the growth and diversity of the good guys that produce all the health benefits and therefore help crowd out the less desirable ones.

Prebiotics are types of fibre which our body’s are unable to digest in the stomach and small intestine so they arrive, undigested, into our large intestine where they are fermented, providing a feast for our beneficial bacteria. Think of it like your favourite takeaway arriving (only it’s healthy!).

Some of the best sources of prebiotic fibre include:

• Onion
• Garlic
• Leeks
• Asparagus
• Jerusalem artichoke
• Chicory root
• Apricots
• Pomegranate
• Apples
• Legumes (lentils, chickpeas, beans, peas)
• Wholegrains (barley, oats)
• Nuts and seeds (almonds, pistachios, flaxseeds)

In addition, most of the carbs we eat (grains, pasta, potatoes) contain starch, some of which is considered resistant starch because it literally resists digestion. In this way it acts in the same way as fermentable fibre and is considered a prebiotic.

Foods that contain good amounts of resistant starch include:

• Cooked and cooled potatoes, rice and pasta
• Oats
• Green (unripe) bananas
• Most legumes

All our microbes have different favourite foods so, diversity is key to keep them all happy!

The benefits for our mood

When prebiotic fibres are fermented they are broken down into substances called short-chain fatty acids (SCFAs) and it’s these substances that are thought to play a key role in the gut-brain crosstalk.

SCFAs have powerful anti-inflammatory effects and there is now strong evidence implicating inflammation in mood related conditions such as anxiety and depression.

SCFAs are also thought to stimulate the production of key mood regulating neurotransmitters including serotonin, dopamine, GABA and noradrenaline. Deficiencies in these neurotransmitters are long thought to contribute to negative moods and are often the target of antidepressant and antianxiety medications.

So, could prebiotics be the secret to a better mood? Given the important role they play in our gut health and the influence that has over our mood…I certainly think so.