As a nutritionist specialising in gut health, I see many clients with common gastro intestinal symptoms such as constipation, diarrhoea, bloating, irritable bowel syndrome, inflammatory bowel disease, candida overgrowth, leaky gut, small intestinal bacteria overgrowth (SIBO), coeliac disease, gastro esophageal reflux disease (GERD) and food allergies, sensitivities and intolerances. However, from clinical experience I can confirm that the gut is at the centre of most health issues and must be taken into account for all of my clients no matter what they have come to see me for.  The  health of the gut can have an effect on the occurrence of autoimmune conditions, multi system disorders such as chronic fatigue syndrome and fibromyalgia, mental health issues, hormone imbalances, a person’s ability to lose or gain weight, the occurrence of chronic disease etc. If the gut is not working well then it can have a knock on effect on most body systems.

 Gut Microbiota

The gut microbiota is the collection of bacteria (and a few other organisms) that live in and around our body. More than a trillion microbes live in our gastrointestinal tract, the majority of which live in the large intestine. In the past, due to stool testing via a Petrie dish, which only the encouraged the growth of oxygen dependent microbes, it was thought that we only had a few different types of bacteria in our gut such as Bifido bacteria and Lactobacillus strains. Fast forward a few decades and DNA testing has shown that we have 4,000+ different types of bacteria residing in our gut and bifidobacterial and lactobacillus are only a tiny percentage of them.

If all is working well, the relationship between us and our gut bacteria should be mutually beneficial.

Our gut microbiota helps us by:

  • Protecting us against harmful pathogens
  • Influencing hunger and appetite and metabolising food
  • Strengthening our gut lining
  • Interacting with our immune system to keep it in balance
  • Manufacturing neurotransmitters and keeping our mood happy
  • Digesting some of our food for us
  • Making some vitamins, amino acids and short chain fatty acids

We help the bacteria by giving it a place to live and food to eat.

A ‘healthy gut microbiome’ is different for everyone. Microbial diversity has shown to be an important factor in a well functioning gut as well as stability and resistance to changes such as antibiotics or infection. When our gut microbiome is varied and healthy, it produces more antioxidants and short-chain fatty acids, has better fat breakdown, keeps out immune system happy, has healthy conversations with our brain and keeps gut inflammation low.

Dysbiosis is when the microbiome contains more ‘bad’ bacteria than is functional in the gut and is out of balance. In this less healthy state, the body produces less short-chain fatty acids, has an increased risk of insulin resistance, adverse gut symptoms, chronic inflammatory conditions, mental health conditions, fatigue, hormone imbalances, weight gain, cardiovascular disease etc.

Environmental factors such as diet, medications, stress etc. have a major impact on the composition of our gut bacteria. Here is an infographic showing a spectrum between a healthy microbiome and dysbiosis:

Taken from Role of the Gut Microbiome in Nutrition and Health

Gut Health and Weight Loss

Gut health is something that I look at very closely with clients starting their weight loss journey. If there is some degree of gut dysbiosis present in a client, it can greatly impact their ability to manage their weight. This is because there is a connection between long term weight gain and low microbiome diversity and dysbiosis. The bacteria, yeasts etc. that are housed in our gut metabolise our food and can determine how well we gain or lose weight.  They also play a major part in the foods that we crave. A yeast overgrowth in the gut may play a big part in sugar cravings – yeast loves sugar. Also, a high sugar diet encourages the sugar lovers in our gut to grow so there is a perpetual cycle of feeding and breeding. Beneficial bacteria and yeasts love fresh fruits and vegetables and non-beneficial bugs tend to love refined carbohydrates and white sugar. I see many clients who have uncontrolled sugar cravings and it is coming from the bugs in their gut. The solution is to starve the bugs out via a low sugar diet and encourage the ones that you do want with lots of fruit and vegetables. It may take a few weeks or months to turnaround but sugar cravings are banished forever and weight management becomes much easier.

Gut Health and Anxiety

The gut is sometimes referred to as “the second brain” because of how many signals our gut bacteria send to, and have a direct effect on, the brain. There is a large nerve called the vagus nerve that connects the gut to our brain. The communication between the gut microbiome and the brain is called the ‘gut-brain axis’. Around 70% of our feel-good neurotransmitter, serotonin, is manufactured by our microbiome in our gut. Therefore, if the gut is not working well, the brain is not working well. Dysbiosis and gut inflammation have been linked to mental health issues such as anxiety and depression and even long-term chronic issues such as dementia and Alzheimer’s disease. Research looking into the impact of adding more gut-friendly foods to the diet and supplementing probiotics on mental health are finding promising results. I always take the state of the gut into account when working with mental health clients.

How to Heal Your Gut

The health of the microbiome plays a huge part in the health of the gut. However, there are other factors that may play a part in the incidence of adverse gut symptoms. I find that many of my clients have been prescribed antacids but their stomach acid is actually too low (this is called hypochlorhydria). Low stomach acid has a knock on effect throughout the gut and can cause growth in all of the wrong bugs. Our beneficial gut bugs love an acidic environment and pathogenic bugs love alkaline. Also, stomach acid mixed into our food when we digest it triggers the release of digestive enzymes further down the digestive tract. Low stomach acid usually equals low digestive enzymes and this means that you are not going to break down your food properly. This means that intact food gets down to the large intestine and gets over fermented by our bacteria causing gas, bloating and pain.

Also, our gut has 2 phases – digestion and cleaning. We should eat a meal then rest for a few hours. This allows a cleaning wave to pass through the musculature of the gut, pushing all debris down into the large intestine. If you are grazing all day (3 meals per day plus snacks has been very much encouraged in the Western world) then there is lots of digestion going on but not much cleaning. That means that food particles stay stuck up through the digestive tract and bacteria that should be pushed down into the large intestine where they belong, are allowed to remain in the small intestine where they can wreak havoc.

Food allergies and sensitivities can play a huge part in gut symptoms. Clients can get very confused because they may have been able to tolerate a food for years then all of a sudden it starts to cause a problem. This may be due to a shift in the composition of the microbiome (a round of antibiotics or surgery would do the trick) or something changes in the gut such as the introduction of  parasite. I also see lots of clients who have had symptoms since childhood (always suggests a food reaction)  but it has become their ‘normal’ so they may have been living with issues for a long time before they decide to do something about it. Lots of food reactions can be caused by a condition called leaky gut. Leaky gut is where the integrity of gut cells has become compromised leading to leakage of food particles etc. through into the blood stream. This results in an immune response and multiple food allergies and sensitivities. Leaky gut can be caused by stress, over exercise, gluten consumption, toxin exposure etc. so requires a multi factorial treatment protocol.

Parasites are also incredibly common. I always ask my gut clients if they have ever had a stomach bug overseas or a bout of food poisoning. There could have been a nasty bug in there for years. Stool testing usually gets to the bottom of this issue.

The reason I love working with gut health clients is because every single person that walks through my door needs their own personalised solution. One person’s bloating may have a completely different cause compared to another. Here are the many ways that I have healed my clients’ guts:

  • More fibre
  • Less fibre
  • Increase fruit and vegetables
  • Low histamine diet
  • Gluten free diet
  • Dairy free diet
  • Food allergy and sensitivity exclusion diet
  • Low FODMAP diet
  • Supplemented stomach acid
  • Supplemented digestive enzymes
  • Supplemented DAO enzyme (breaks down histamine)
  • Gut healing supplements
  • Longer breaks in between meals
  • Supplemented prebiotics
  • Supplemented probiotics
  • Reduced protein
  • Reduced sugar
  • Reduced carbs
  • Increased carbs
  • Recovery program from antibiotics
  • Sent to GP for antibiotics
  • Sent to the GP for anti fungals
  • Low oxalate diet
  • Low sulphite diet
  • Increased water intake
  • Increased exercise
  • Reduced exercise
  • Changed their routine around sports drinks and gels
  • Worked on stress management techniques
  • etc. etc.

As you can see, there are a lot of things that can be going wrong with your gut. There is usually a combination of the above. It will be a challenge for you to work this out on your own. Most of my gut clients have no idea what histamine, oxalates, sulphites etc are never mind how they are affecting their gut. I have been working with gut health clients for years so sometimes it is very easy for me to identify the problem immediately (I love a good food and symptoms diary!). Sometimes we have to do some testing to get answers. However, we get to the answers eventually and after a month or so, the clients generally feels a lot better and well on the road to 100% recovery.

Gut Health Nutritionist

If you think you have underlying gut issues that are stopping you from reaching your health goals, book in a consultation with me so we can find the root of the problem.


Fiona is one of my all time favourite people