Leaky gut syndrome is an unpleasant condition that can affect humans, dogs and other animals. Dr. O’Connell explains the cause and offers tips on diagnosis and treatment.
Introduction
One of the best ways to understand how leaky gut syndrome (LGS) may be affecting a dog, cat or other animal in your care is to consider how the condition affects humans.
In humans, diagnosis often comes after a patient gets, literally, a gut feeling that there is something not quite right with their health. They may be constantly stressed, anxious, overwhelmed. Unable to maintain a healthy weight. They could be experiencing bloating, cramps, flatulence and have unexplained aches and pains. For some people there will be one or more of the ‘itis’ health issues: gastritits, pancreatitis, dermatitis, colitis, glomerulonephritis, cystitis, cholangitis, to name but a few. ‘Itis’ equals inflammation.
LGS is well researched in humans, and the underlying pathology is paralleled in our pets. It is often referred to as gastrointestinal hypermeability. My preferred term is disrupted gut syndrome, since I feel this better represents all the types of disruption that causes the pathology that is occurring. However, for the purposes of this article we shall stick with the best known and most widely used term.
LGS has been shown to lead to disease in all other parts of the body including but not limited to, the brain (it can have a role to play in anxiety, schizophrenia, chronic fatigue syndrome, Alzheimer’s disease and autism), the skin, the lungs, the kidneys, the pancreas, the liver and the heart (see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9862683/)
In this article I will be looking at the functions of the gut, the physical changes (pathology) that occur to the gut, and what causes the pathology to develop. I will also consider what can be done to reverse the process. In my experience ir is possible to massively improve and sometimes even cure not just gut disease but many other disease processes in our pets.
A beginner’s guide to the Gastrointestinal System
The function of the gastrointestinal system is to process food and drink for absorption into the body. If done correctly those processes result in the correct component parts entering the body for use in the metabolic pathway that results in the production of energy. This energy is the fuel that enables us to function, and maintains and repairs the system in an intricate well organised way. Disruption to the smooth running of this system ultimately results in disease.
The physical gastrointestinal system includes all tissue that food and nutrients inhabit, starting with the mouth, then into the oesophagus, the stomach, the small intestines, into the large intestine, with final waste products expelled by the process of defecation.
No area of the body is a standalone system, and the gastrointestinal system is no different. The gall bladder that sits within the liver, and the pancreas which is located alongside the duodenum (the upper small intestine) both produce products to help with the breakdown of nutrients, and both communicate directly with the duodenum via narrow tubes (ducts).
And then there is the all-important gut microbiome. An external ‘system’ made up of many different types of organisms, including bacteria, viruses, protozoa, fungi and all manner of other bugs, some of which have probably yet to be identified by science due to the complexity of this vast system. Its health is key to a healthy body (and healthy mind). Disruption of this microbiome contributes massively to LGS resulting in many serious diseases. There are many more of them then there are cells in our body, so we had better treat it right!
The development and causes of the ‘leaky’ gut
A healthy gut consists of a defensive barrier of cells called enterocytes, joined by tight junctions. These enterocytes have tall projections called villi that increase surface area for absorption of nutrients. A leaky/disrupted gut consists of a gut lining that has inflamed cells, short, stumpy, blunted villi, (and therefore reduced surface area for absorption), and faulty ‘tight junctions’ leaving ‘gaps’ and weaknesses in the defence barrier of the gut. In addition to this the all-important gut microbiome ends up out of balance, and this can be very harmful indeed. Symptoms may not be seen until these events have been happening for a while, or they will come and go, or they might suddenly flare up if an overwhelming assault (such as an infection) occurs.
Due to the reduced defence capabilities, the lack of surface area for absorption and a disrupted microbiome, the gut fails to protect the body from invaders allowing all manner of things through into the body, ranging from toxins to allergens to incorrect nutrient molecular structures. In the gut the main causes of this include toxic chemicals and most importantly harmful food types.
Professor Tim Spector (Kings College London) founder of the Zoe programme has proved beyond doubt that, in people, good food choices make a huge difference between health and disease. The Zoe programme involves testing sugar metabolism, fat metabolism, and faecal microbiome diversity and abundance.
There are rapidly increasing numbers of researchers and clinicians from around the world who are working on similar projects. The terms for the medical approach that these nutritional clinicians take are Functional medicine or Integrative medicine. Typically, these clinicians are medical Doctors who have learned how powerful a nutritional approach is. Dr Steven Gundry, in particular, stands out. He is a specialist cardiologist who has performed multiple heart transplants in children, devised mechanical devices for the heart, and is the author of many illustrious medical research papers. Through a client experience with a patient who he calls ‘Big Ed’ he changed to a nutritional approach, and now rarely has a reason to perform heart surgery, such is the success of his nutritional programme. His book ‘The Plant Paradox’ is a very interesting read.
The basic premise behind the functional/integrative approach is to first test for certain inflammatory markers and metabolic flexibility, then treat the patient by removing ultra processed foods (think take-aways, ready meals, bread, cakes, biscuits, pasta), and all refined sugar, refined carbs and bad fats, (such as industrial made trans-fats) from the diet and have them eat whole foods exclusively. The patient is then re-tested to see what progress has been made internally alongside the feedback from the patient regarding symptoms. It is largely a bespoke approach with more detailed nutritional changes being made to the programme at each visit, alongside various lifestyle changes (exercise and stress management for instance). The ongoing conversation provides the patient with an understanding of the rationale for those changes being made, and ultimately the autonomy for them to be able to maintain their own day to day health.
So, what about our pets?
The treatment approach for our pets
How can we best help our pets to thrive and not just survive? How can we reduce symptoms or indeed cure chronic conditions such as itchy skin, fussy eaters, ongoing gastrointestinal upset, ear infections, anal gland impaction, obesity, pancreatitis, and more?First seek out a vet who has an interest in nutrition. This is easier said than done, since nutrition modules in veterinary science degrees rarely have an all-encompassing approach to pet food that includes the mention of fresh food as well as dry and canned food. (Our medical colleagues, similarly, are not taught about how the correct nutrition can both prevent and cure health issues).
Let’s now get personal. After twenty three years in general practice I can safely say that a nutritional approach is my most successful ‘treatment’, and therefore, my primary therapy. I have succeeded with patients of all ages and with many different diseases including skin, gut, behaviour, immune-mediated disease, forms of epilepsy, urinary issues, stress and more. It is rewarding on very many fronts, most importantly seeing patients get better, but also that it can almost always be done relatively inexpensively.
No pet NHS exists. In essence, Veterinary medicine is private health care. Budgets often do not allow for much if any testing of inflammatory markers or other tests. Plus, the development of these tests is often behind those available in the human field. Happily, research into the canine microbiome is underway at a couple of UK institutions. Enhanced understanding of this very complex system will enable a more targeted functional medicine approach to disease in the future, which is very exciting indeed, so watch this space. On the whole though, currently, we in veterinary practice rely much more heavily on a thorough history, a physical examination, photos of output (i.e. faeces!) and detailed information and feedback from the pet owner.
The nutrition programme chosen needs to align with the accessibility, budget and beliefs of the person (owner) instigating it, so there is no ‘one size fits all’. However, below are four fundamental changes that are very helpful in the nutritional approach for all our canine and feline patients, regardless of their symptoms/disease:
- Stop feeding grains. This includes those not just in the main meal but also in treats, chews and leftovers. And yes, rice is a grain!
- Stop feeding the E numbers (preservatives, flavourings, colourings, etc. found in many ultra processed pet foods).
- Feed ingredients in proportions as close to nature as intended i.e. species appropriate. Cats are obligate carnivores and dogs are mostly carnivorous. One problem with dry food (i.e. kibble) is that it is dry – adding water to it doesn’t help. The water in raw food is an important part of its value.
- Don’t allow grazing on food all day. If the food hasn’t been eaten within twenty minutes remove it. If the gut is constantly utilised in digestive processes, it has little time to repair and replenish cells.
In addition to a diet change to include the fundamentals above the right pre-biotics, pro-biotics, and post-biotics – plus vitamin and mineral supplements – can be used to great effect while the gut is in the disease resolution and repair stage.
In severe cases the intestinal flora (gut microbiome) itself may be so depleted that it needs replenishing directly. This can be done by a treatment called faecal microbiome transplant, (it has been done in humans to great effect). In our pets, currently (freeze dried faecal capsules are being developed as is used in humans), it involves performing a ‘reverse’ enema, by instilling a healthy faecal solution into the large bowel. The healthy donor dog will have had their faeces tested for parasites and pathogenic bacteria. One application is often all that is needed.
Once clinical symptoms have resolved supplements may only be needed intermittently, plus the main meal ingredients can be made more varied since the microbiome is sufficiently diverse to process the different ingredients coming its way.
Often it is an individually targeted trial and error approach to see which foods suit each patient best. This can take weeks to months depending on the severity of the disease, but I have seen results in less than a week. Know that there will likely be bumps along the road, such as your pet scavenging that hamburger bun found by the park bin. Ultimately however the effort is worth it since you end up with a happy, hopefully symptom-free pet and reduced vet bills!
A final word
As we know for ourselves, the pillars of a healthy life include optimal nutrition, good exercise, clean air and water, good stress management, and a happy social life to achieve our full potential. Our pet’s health relies on those same foundations too.
Things that can cause disease are only able to enter the body through three body systems: the respiratory tract, the skin, and the gastrointestinal tract. Of all these body systems the gut is arguably the easiest to treat and perhaps the most impactful in protecting and preventing our pets from many diseases.
About the author
Bella O’Connell is a veterinary surgeon working in general practice who has been using nutrition as her primary therapy since graduating in 2002. Alongside her clinical work she offers on-line (Zoom) and in person (North Dorset) nutrition consultations. This is done in collaboration with your regular vet to ensure the best possible outcome. Importantly, the nutrition plan is designed to align with your budget, beliefs, & lifestyle.
contact@thenutritionvet.co.uk
References & useful links
Leaky gut and the ingredients that help treat it. 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9862683/
https://zoe.com/learn/what-is-leaky-gut
The Leaky Gut: Mechanisms, Measurement and Clinical implications in humans. 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6790068/
https://www.ifm.org/about/profile/steven-gundry-md/
https://vcahospitals.com/know-your-pet/leaky-gut-syndrome-in-dogs
Can Atopic Dermatitis in dogs be associated with intestinal inflammation. 2024. https://www.longdom.org/open-access/can-atopic-dermatitis-in-dogs-be-associated-with-intestinal-inflammation-109451.html
The Relationship between Canine behavioural disorders and Gut microbiome and Future Therapeutic Perspectives. 2024. https://www.mdpi.com/2076-2615/14/14/2048
Effect of Sacchromyces Boulardii in dogs with chronic enteropathies. 2017. https://pubmed.ncbi.nlm.nih.gov/29212912/
Canine Faecal Microbiome Transplantation: Current application and possible mechanisms. 2022. https://pmc.ncbi.nlm.nih.gov/articles/PMC9413255/
