Gut Health

The human gut is host to a highly complex ecosystem of microorganisms. The presence and activity of these microorganisms is truly the foundation to our health and wellbeing.
View TestsBack to all treatments

Book complimentary discovery call


The human gut is host to a highly complex ecosystem of microorganisms. The presence and activity of these microorganisms is truly the foundation to our health and wellbeing. They play a key role in the development of the immune system, digestion of fibres, production of energy metabolites, elimination of toxins, regulation of hormones, synthesis of vitamins and neurotransmitters and in the defence against pathogens and the list goes on. So, it makes sense that supporting gut health is central to our functional medicine approach, here at the London Clinic of Nutrition.

a lady resting in bed
A lady standing on a bridge over the river thames
A picture of a mix of fruit, vegetables and oil

How do you know if your gut health is bad?

When you hear about poor gut health, you might think of conditions like constipation and diarrhoea [1] [2] but an unhappy gut can manifest itself in many other ways:

  • Unexplained weight gain – several studies now suggest that overweight and lean people have very different microbial diversity within the gut [3]. These differences may affect appetite and satiety, resulting in different eating behaviours [4].
  • Skin issues – The gut-skin axis is a hugely exciting topic. Emerging research in this area suggests that poor gut health has a profound effect on our skin’s functioning and microbiome [5].
  • Mood swings, depression, anxiety [6]. A recent review suggests that the gut microbiome and its interactome also deserve attention in the understanding and treatment of psychiatric disorders. 
  • Brain fog and memory problems: The link between our microbiomes and our brains, also known as the microbiota-gut-brain axis, is one of the hottest topics in neuroscience right now [7].
  • Sleep disturbances: The majority of the body’s serotonin, a hormone that affects mood and sleep, is produced in your bowel. So gut damage can impair your ability to sleep well.
  • Recurring cold and flu and other infections. 80% of our immune health is located in our gut so it makes sense to look after it to fend those bugs off.
  • Food allergies, intolerances and sensitivities sometimes to foods that were not a problem before can be a result of a negative shift in your gut microbiota. Find our articles on food sensitivities and digestive health here. 
  • Sluggish metabolism, low energy and fatigue – exciting new research has revealed that there is a strong association between chronic fatigue/ME and dysbiosis of the gut [8].

How is gut health tested?

There are typically two main routes to test your gut health at our gut clinic:

  • Breath test

The breath test is an easy, non-invasive test that measures gases: hydrogen (H2) and methane (CH4). The breath tests usually use glucose and/or lactulose as substrates to diagnose Small Intestine Bacterial Overgrowth, also known as SIBO. 

  • Stool test

Depending on the condition we are looking to investigate, there are many levels of stool tests available. A fully comprehensive stool test will typically measure gut bacteria, yeast, fungi and parasites; markers of inflammation, immune function and markers for digestive health. In our experience, the best and most accurate type of stool tests uses PCR-DNA analysis. 

Find out more about stool and gut health testing here.

How long does it take to get your gut health back?

It is a question we get quite often and the answer depends on many different factors:

  • How would you describe your digestive health?
  • What are your current symptoms and how long have you had them for?
  • Have you seen a gut health doctor through the healthcare system?
  • Have you been to a gut health clinic before? If so, what treatment have you received? 

As one of the largest functional medicine clinics in Europe, we will investigate all possible routes and causes during your visit. With this approach, our gut health specialist London nutritionists look closely at the myriad of interactions among genetic, environmental, and lifestyle factors that can influence long-term health and complex, chronic disease and will have much greater success at reversing the illness. 

Find our functional gut clinic reviews here. 

What can I do to improve my gut health symptoms?

While a good diet is a foundation of building a healthy microbiome, other factors are fundamental too. Here are some of the most powerful ways to get a healthy gut.


  • Eat the rainbow: your bowel loves getting a cocktail of plant chemicals from different coloured fruits and vegetables. They provide different phytonutrient compounds that have different functions in the body; reduces inflammation, improves gut immunity, provides antioxidant properties and may exhibit some very exciting physiology specific mechanisms.

  • Eat a fibre-rich diet: Eating a hunter-gatherer diet that is fibre-rich is a fundamental start. Aim for at least 30grams of fibre.
    • Say no to sugar and processed foods: Most processed foods lack fibre and nutrients and are high in calories. An unfriendly combination for your bowel. 

    Lifestyle suggestions

    • Stress: Studies have found that stress triggers a fight-or-flight response that releases hormones in various parts of your body, which in turn affects your microbiome [9]. To make matters worse, altered gut microbiota then affects the regulation of neurotransmitters, increasing stress levels further [10].
    • Sleep is so important for the body to carry out some of its maintenance work. Healing, repairing and recovering are essential processes for our overall health. Lack of sleep and stress may increase inflammation and impair bowel function. [11]. 
    • The gut microbiome is easily disrupted by environmental toxins so try and opt for organic produce, more natural household products and skincare to minimise exposure to the toxic load.

    The London Clinic of Nutrition is the largest functional medicine clinic in Europe. We are an award-winning clinic having received the UK’s highest award from Integrative Healthcare & Applied Nutrition (IHCAN). We combine industry-leading nutrition and functional medicine expertise, alongside the latest in-house testing, so we can attend to all your health needs in one trip. 

    What is the best product for gut health?

    Unfortunately, the growing demands of a modern lifestyle are having a significant impact on our nutritional health - stress, anxiety, lack of sleep, dieting and poor nutrition all impact the body’s ability to absorb and utilise the nutrition needed for digestive health. There is now a wealth of scientific knowledge and evidence around the use of nutritional supplements and their beneficial effects on gut health. Here are the key supplements you may want to consider:

    • Prebiotics- oligosaccharides such as GOS, FOS and inulin may be beneficial as they promote beneficial gut bacteria [12].  
    • Probiotics - when therapeutic support for the intestinal mucosal and/or epithelial barrier is required, an increased intake of probiotic bacteria alongside prebiotics is prudent. Specific strains of probiotic bacteria have been shown to improve bowel integrity, such as Lactobacilli and Bifidobacterium strains [13]
    • Vitamin and mineral that contains nutrients that strengthens the mucosa and provides gut integrity support: vitamin A, C, D and zinc [14].
    • Colostrum may also be useful as it provides immunoglobulins and other gut health-promoting nutrients [15].

    Due to the complex pathophysiology of gut conditions, it’s important to approach it with a holistic, in-depth and comprehensive support. So, before embarking on a supplement spree we would always recommend that you consult one of our practitioners at our clinic. Get in touch for a complimentary discovery call to discuss your health concerns and how to match you with the most suitable nutritionist.

    Where can I get more advice?

    Choice is a great thing, but it can be overwhelming. The supplement market is full of products, and many are fantastic but some aren’t. Same goes for testing companies and labs. It takes a lot of time to learn, understand, and trust labs, brands and products. Our gut specialist London practitioners have done the legwork for you. We have investigated and found the best, most accurate and highest quality tests and products through extensive education and research. 

     Get in touch to find out more

    Our relaxing treatment clinic is located in Marylebone, London, a few minutes away from the renowned Harley Street. We offer a range of appointments in-person or online. Get in touch to discuss your health concerns and how to match you with the most suitable practitioner.

    Sign up to receive free recipes, health tips and more