The Gut-Brain Connection and Mediterranean Diet

September 4, 2020

Going to a dietitian or nutritionist can help you find a diet suited to your preferences, allergies and health conditions, and can even have a positive effect on your mood. Research is growing all the time on the links between food and individuals – here, nutritionist Charlotte Harrison explains the link between the brain and the gut, and shares some easy implementations inspired by a Mediterranean diet.

by Charlotte Harrison


Fibre, whole grains, probiotics and prebiotics… Just when you think you know all there is to know about good gut health, science works its magic and discovers even more information to help us best maintain a relationship with our digestive health. 64% of the world’s population now actively exclude foodstuffs from their diet and 72% of US consumers say finding healthy food is difficult, whilst a staggering 76% of consumers have unintentionally consumed food that’s restricted from their diets. In other words, it’s more important than ever to be aware of our digestive and nutritional needs.


To understand good gut health, we first need to understand the basics of what our gut is and how it works. When we talk about our ‘gut’, we’re referring to our intestines, and more specifically the gastrointestinal tract that travels the length of our bodies. Within every gut is a community of microbes including yeast, fungi, and various bacteria, which collectively is known as a microbiome.

A microbiome is a very complex system comprising of more than 1,000 different types of microbes. In fact, research has shown that there are ten times the number of microbial cells in the gut than in the rest of the human body combined, and that these communities of cells can weigh up to 5lbs. With so many microbes, it’s no wonder we still have a fair way to go in regards to understanding what each one does and how it works. To further complicate things, every person’s microbiome will be slightly different in accordance with their own individual body.

One thing we do know is that the microbes in our gut have actually been found to communicate with our central nervous system as well, almost as though the gut is able to act as a second brain. The science around the gut-brain connection (known as the gut-brain axis) is becoming more and more understood with new research. One study even found that when test subjects with severe to moderate depression were put on a certain diet – the Mediterranean diet – they showed a 30% improvement in their symptoms.

Recent research has discovered that the microbiome is more crucial in the world of health than previously thought. There have been links found between the gut microbiome and Crohn’s disease, IBS, heart disease, skin conditions and even mental health. Plus, with 70% of our immune system in our gut, it’s definitely worth looking after, especially during times during which health and immunity may be at risk or compromised.

We know that there are links between certain microbes and medical conditions, but right now we don’t have enough research to tell us which ones act in which specific ways. Despite this, the effects are still clear – the Mediterranean diet has recently been championed as being one of the healthiest diets for gut health, owing to its high portions of whole foods and low portions of foods containing saturated fats and sugars. Here’s what it looks like.


Fruits and vegetables

Many fruits and vegetables contain high amounts of vitamins and fibre, making them great sources of nutrients. Fibre can’t be readily digested by the body, but they can be digested by certain microbes. Fibre acts as a feed to make sure they stay alive. Some high-fibre fruits you’re likely to already have in your kitchen include apples, bananas, raspberries and strawberries, with raspberries coming in at 8g of fibre per cup. When it comes to vegetables, sourcing dark, leafy vegetables is a safe bet. Carrots, beetroot, broccoli, kale and artichokes will all provide you with a good portion of fibre.

Avocado is another good option when it comes to your salad, offering healthy monounsaturated fats which have been shown to help in lowering blood pressure and protecting against heart disease.


Whole grains and legumes

Whole grains and legumes including chickpeas, soybeans and the lentils pictured above also contain fibre to aid us in healthy digestion and a happy gut. Whole grains also contain non-digestible carbs which are not digested by the small intestine, but by the large intestine. These carbs make their way through the digestive tract to the large intestine, where they are broken down, boosting metabolism and ensuring steady blood sugar levels.


Lean red meat is optional, but keep consumption minimal

Red meat is an optional part of the Mediterranean diet. If you do include it, make sure you’re selecting something that isn’t processed, or too high in saturated fats. Participants in the study which evidenced the benefits of the Mediterranean diet were consuming red meat  3-4 times per week at the most, so try another source of protein (such as the beans or legumes mentioned previously) for your dinner a few nights a week.


Olive oil

If you were to pick just one oil to use, olive oil would a great choice. Other than the benefits of its fatty acids on gut microbiomes, extra virgin olive oil has also been linked to improved cardiovascular health, type 2 diabetes and even mood. The participants who contributed to the Mediterranean study mentioned above consumed 3 tablespoons of olive oil per day.


While not necessarily consumed in the Mediterranean diet, another food to be given a worthy mention is fermented foods, preferably unsweetened, such as kimchi. Fermented foods are great as they can contain up to twenty different types of microbes of their own, which is great for keeping a large amount of microbe diversity in the gut. Always check the labels though, as a lot of kefir products sold in supermarkets, for example, can contain high amounts of sugar, which is not good to consume on a regular basis. Even artificial sweeteners can really change the gut microbiome, and not in a good way.


Due to research, personalised eating plans are becoming more specific to the individual, there’s no such thing as a universally healthy diet for everyone. There are some interesting studies which show that even when the genes of two people are identical, as in twins, their microbiomes can still be very different. This suggests that individual microbiomes may be affected by our day-today diets in many different ways, proving that there are benefits of looking after your gut. A well looked-after gut means better health.

Going to a dietitian or nutritionist can result in a plan which is suited to food choices, allergies, health conditions, and now so much more, like boosting your mood and improving mental wellbeing. We are finding out so much more about the links between food and individuals, including how our digestion functions and the impacts the food we consume has on it. Remember, if you do have any diet recommendations or questions, go to a registered nutritionist or dietitian.


Find out more:

Charlotte Harrison is a nutritionist for Spoon Guru. Charlotte graduated from University of Roehampton (UK) with a Bachelor of Science in Health & Nutrition in 2018.  She holds a license and certification from the Association for Nutrition, and a certificate in Food Health & Safety Level 2 from the Food Standards Agency.
Charlotte is currently nutritionist for Spoon Guru, a London-based AI food technology start-up that has developed a unique food search and discovery engine to cater for individuals with specific requirements or health objectives. Spoon Guru combines AI and machine learning with nutritional expertise to enable food retailers to deliver a highly-personalised experience tailored to each consumer, based on their distinct and unique dietary, health and wellness needs.

Posted by: Leah Russell