Gut Instinct, Which Diet Is Best?

We take a look at gut health from the outside, looking in – from the perspective of the latest diets to be gaining traction, (Mediterranean) as well as the perennial (Paleo).

The classic probiotic argument eat complex carbs and good bacteria will thrive has picked up steam this year with the popularity of fermented foods within the functional food category, like kombucha, and sauerkraut.

Wider trends of health – bodily and mental – and the environment have culminated in 2018’s attack on sugar, dairy and waste, building this promotional platform for gut health.

As a result, the probiotic market is growing by 7% every year (The Grocer ‘Functional Foods Category Report’ 2018); and alongside waves of NPD (some even celebrity endorsed, e.g. Jonny Wilkinson’s kombucha), and mountains of new research (from the reputable to the sensationalist), it’s no doubt that gut health is the star of functional foods.   As our gut microbiomes are angled beneath the spotlight it’s worth outlining the pros of a healthy gut.

Gut health promotes diversity and balance within one’s diet; it focusses on the natural and less processed options available. Positive gut health is correlated with cardiovascular health; a functioning digestive and immune system; and, sometimes, weight loss (Harvard Medical School, ‘Healthy Gut, Healthy Heart?’ June 2018). High energy levels, regular blood sugar, and mental well-being are among other healthy gut desirables.

Luckily for us, gut health has been on the research agenda for the past century, so there is an abundance of information available. The following is a condensed list of a few diets and their generalised positive effect on gut health.


‘Properly’ functioning bodies are becoming a nostalgic desire causing consumers to dive into diets of the past. This preagricultural diet consists of consuming high protein, low CHO foods. It is typically targeted and adopted by those in western societies.

For those adopting the Paleo diet in management of IBD, and to a chorus of success, the Paleo diet cuts out gluten, the main inflammatory stressor. It also encourages consumption of high carb foods, and given those with IBD are typically underweight because inflammation prevents absorbing macronutrients, a big benefit of the diet addresses nutrient deficiency. (Paleo

For those without IBD, a benefit of the Paleo diet is a greater microbial diversity (Science Magazine, Gut microbiota… diet and human health, Nov 2018). In general, the higher the microbial population, the healthier the gut.

Vegan & Plant-based

The plant-based diet is among the trendiest of 2018; with a plethora of NPD readily available and constantly in the pipeline, it hardly needs an introduction.   In general, plant-based diets are associated with positive health and lowered disease risk. (Science Magazine, Gut microbiota … diet and human health, Nov 2018). Very simply put, the plant-based diet is high in fibre (vegetables and grains), and natural sugar (fruit).

Polyphenols, found in plant foods including fruits, vegetables, grains, tea, coffee, and wine can positively affect the gut microbial population. Polyphenols are prebiotics – they feed the probiotics thus contributing to high absorption of natural nutrients. (Today’s Dietitian July 2018; Polyphenols are associated with their related role as antioxidants – the ability to combat cell damage. For gut health, polyphenols increase the amount of good bacteria in the gut and also inhibit the growth of potentially harmful bacteria.

Phytochemicals are found to be diverse in a plant-based diet; phytochemicals have direct antimicrobial and anti-inflammatory effects in the gut. They also can be modified by “microbial enzymes into metabolites with increased bioavailability and altered bioactivity” (Science Magazine Nov 2018).


Less focussed on weight loss and more so on variety, taste, and authenticity, the Mediterranean diet focusses on diversity, but shares some common interests with the vegan and paleo diets – food and drink products closer to the raw material, less refined sugar, more complex carbohydrates.   Often dubbed the ‘heart healthy’ diet, the Mediterranean diet includes a vast amount of plant-based foods, so reaps in the aforementioned benefits of the Paleo and plant-based diets. The same calories as the traditional Western diet, it replaces the ‘bad’ types of fats and carbohydrates, e.g. saturated fats, for a favourable gut microbiome.

Lactobacillus, a ‘good’ gut probiotic, is increased by 7% on the Mediterranean diet (Frontiers in Nutrition, ‘Gut Microbiome … Western or Mediterranean Diet’April 2018). Not a lot of research has been carried out on the Mediterranean diet and gut health, but the generalised opinion is that the emphasis on a variety of the plant-based, rather than the active exclusion of the animal-based, is the most positive factor of the diet.


While genetics, ageing, stress, and antibiotic intake all affect gut health, food is a relatively controllable factor, one that impacts host health and metabolism, and is therefore one of studious interest, especially in exploring disease management.

It is commonly perceived that fermented foods – kombucha, kimchi, sourdough, sauerkraut, prebiotic and probiotic foods and drinks – are the key to good gut health: diverse microbiota. However, such nutrients are not consumed in isolation; studying gut health within particular diets could be a useful methodology for nutritionists, dieticians, and the average joe alike.

This is a trend which is already expanding in our capital city. London is  home to a number of restaurants and businesses which are prioritising our gut over the rest of our body. High Mood Food, Press, Leon and Fermented by Lab are taking gut health seriously and are infusing their dishes and even their subscription boxes with ingredients such as Apple Cider Vinegar and ferments like kimchi and pickles to boost your body’s probiotic power. The success of these businesses reflect how consumers are demanding food to help focus on their gut health and is a great focus for future NPD.

Have you got a food product which will make your gut happy or want to know more about this market? Contact Hamish at

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