Gut biodiversity and health
We get a lot of questions about gut health, microbes, and what we can do to contribute to good gut health. Today we are interviewing Maria Berglund Ranten about dysbiosis to find out what it is and how diet and lifestyle impact our gut health.
What is gut biodiversity? Why is it so interesting?
The human body contains trillions of microorganisms, including bacteria, protozoa, fungi, and viruses. They are collectively known as microflora. Gerard Mullin, associate professor of medicine at John Hopkins University, refers to our gut flora as a garden; a magnificent orchard of single-cell life.
Scientists are discovering that this complex ecosystem, sometimes known as the second brain, influences everything from digestion to immune health, nutrient absorption, weight gain, and even the efficacy of certain medicines. Gut biodiversity refers to the variety of living organisms in our intestines. Researchers are discovering that gut biodiversity (and the lack of it) can affect our health.
We have heard about dysbiosis. What is it?
As nutritional therapists, we are interested in both the amount and variety of bacteria in our digestive systems, and the types of gut bacteria. Some varieties cause health problems, like weeds in a garden, while others are beneficial, like bees.
Dysbiosis is a medical term that refers to alterations in the microbiome that can negatively impact health. Purna Kashyap, a gastroenterologist and microbiome scientist at the Mayo Clinic in Minnesota, publishes papers on dysbiosis. He describes dysbiosis as ‘the disruption of the microbial community in a way that harmfully influences the host. This could mean having too many ‘bad’ – inflammatory – bacteria, yeast overgrowth, or parasites.
Dysbiosis can also refer to too little bacteria, both good and bad. Another common type of dysbiosis that may cause IBS is small intestinal bacterial overgrowth (SIBO). With SIBO, you either have too many bacteria in the small intestine or bacteria from the large intestine reside in the wrong place. It is likely a significant cause of the symptoms we call ‘IBS’ - and one that doctors often miss.
Benefits of a healthy gut microbiome
A healthy gut microbiome is symbiotic; it confers health benefits to the human host. A healthy gut microbiota helps to prevent chronic inflammation, protects against allergy development, produces short-chain fatty acids, vitamins, and enzymes, and helps to maintain the gut lining and correct colonic Ph. Healthy gut bacteria also prevent the overgrowth of pathogens, protecting against infections. Healthy gut flora may be associated with healthy body weight and can influence mood, sleep, and the risk of chronic disease.
Tell us a bit about how diet can affect gut biodiversity, and dysbiosis
The exact causes of dysbiosis (and whether it even exists) are poorly understood. It is individual and dependent on several factors, from diet to medication use and illness. Diet seems to play a role, possibly by increasing systemic inflammation that promotes the growth of certain microbes, creating a vicious cycle. Foods that promote healthy gut flora tend to be rich in certain fibres, which ferment in the colon and nourish healthy microflora. Examples include Jerusalem artichokes, bananas, polenta, cruciferous vegetables, berries, beans, and fermented, plant-based foods.
The modern so-called ‘Western’ dietary pattern tends to be low in diversity, high in fat, and low in fibre, fruits, vegetables, and fermented foods. It often consists of an excess of overly processed and pasteurised foods, refined sugars, and animal products. This dietary pattern can increase endotoxins and reduce beneficial microbes important for gut integrity - the condition and function of our gut lining – and even insulin sensitivity. In other words, a ‘Western Diet’ can result in a damaged gut barrier and increase systemic and chronic inflammation. Some studies suggest that this lack of diversity may have other unwelcome consequences, like weight gain. Another thought is that illness itself may cause changes in the gut microbiome. We still have so much to learn!
What else can affect gut flora?
Many factors! The microbiome begins at birth - and perhaps even before birth, in the womb. Our early microbiome is affected by our birth, where we are born, and our early diet. Babies born by cesarean section tend to have a different microflora than those born vaginally. Breastfeeding promotes beneficial gut bacteria, and many medications (particularly antibiotics) have a negative effect. Factors like inadequate stomach acid can lead to SIBO by allowing an overgrowth of bacteria, leading to a vicious circle.
How do you know if you have dysbiosis?
A good, experienced clinician can identify dysbiosis quite easily. We sometimes test for it. There are stool, breath, and urine tests that – especially together - can give a pretty clear picture of your personal gut flora. These can tell us about the different types of bacteria that populate your gut, and the tests also include inflammatory markers, markers of fat malabsorption, and more.
These tests should be used sparingly and only by an experienced healthcare practitioner. They shouldn’t be used in isolation or, at present, be considered diagnostic. Health practitioners can use testing as part of a broader health assessment.
Symptoms of dysbiosis include bloating, gas, diarrhea, constipation, and weight gain (or difficulty losing weight).
Can dysbiosis be overcome?
In our experience, clients' gut health and symptoms improve significantly with dietary and lifestyle changes. Doctors tend to give antibiotics to those with SIBO, if they give anything at all, but in our experience, this is a temporary fix that lasts a few weeks and does not treat the underlying problem. Some antibiotics may temporarily or permanently wipe out beneficial bacteria, which may be why SIBO often returns when treated with antibiotics alone.
In our clinic, we identify underlying causes and try to help you regain balance through diet and lifestyle. We use protocols that have helped many of our clients. This includes dietary and lifestyle interventions and herbal compounds as necessary. Research studies have shown that herbs can be as effective as antibiotics for SIBO, although they can take a little longer to work.
If you could give our readers one (ok two!) pieces of advice on this topic, what would it be?
- Eat a wide variety of whole, unprocessed foods (especially plants), and reduce or eliminate over-processed foods.
- If you have or suspect IBS, visit a certified nutritional therapist or doctor working with functional medicine. Nordic Wellth has helped thousands of people with gut problems to reduce or eliminate their IBS symptoms.
Can we help?
We can provide personalized advice about gut health. You are welcome to contact us for advice and support. Nordic Wellth is a holistic, evidence-based nutrition and lifestyle medicine platform run by Registered Nutritionists and Medical doctors passionate about helping people to meet their health and lifestyle goals.
We offer online consultations and group programmes with professionally-trained nutritionists and wellness coaches.
