Metabolic syndrome is bad news – causing heart disease, strokes, diabetes – but its newly-discovered relationship with our gut health could open the door to some relatively quick and easy solutions
We all know that conditions such as hypertension (high blood pressure), diabetes (high blood sugar), too much fat around the middle and high cholesterol are bad for us. They put us at greater risk of a range of serious medical problems, such as heart attack, stroke and type 2 diabetes. As a group, these conditions are known as metabolic syndrome.
In other blogs, I have outlined straightforward lifestyle changes that we can make – a better diet, more exercise, lowering stress, getting better sleep, etc. – to alleviate these conditions or remove them altogether.
But, in this blog, I want to focus on the bearing that our gut microbiome has on metabolic syndrome.
Studies have suggested a strong relationship between the two and how recent changes in our environment (poor Western diet, sedentary lifestyle and stress) have harmed our gut. But, interestingly, they have also shown how specific therapeutic interventions, with probiotics, prebiotics, and even microbiota faecal transplant, can redress the balance in a reasonably fast and straightforward way.
What is the gut microbiome?
The gut microbiome weighs approximately 2 kg and contains bacteria, fungi (mycobiome), viruses (virome) and protozoa. There are around 100 trillion bacteria and other microbes in the human gut, which collectively have a massive bearing on our wellbeing. Babies delivered by Caesarean section lack healthy gut microbiota that usually gained during vaginal delivery.
The gut microbiome has come more into focus recently because modern environmental factors, such as highly processed food, sedentary lifestyles and stress, inadequate sleep, cleaning chemicals (bleach), antibiotics, have combined to reduce microbiome diversity (diversity is a good thing), elevate inflammation and, with it, the risk of metabolic disease.
Diet part of the problem, but also part of the solution
A diet high in fat and low in fibre can cause dysbiosis (an imbalance in the gut bacteria with more bad bacteria than beneficial ones). This can breach the integrity of the gut wall, causing the leakage of its contents (including a bacterial toxin known as lipopolysaccharide (LPS)) into the circulation. This itself results in low-grade inflammation, which plays havoc with your ability to process sugar and carbohydrates, leading to insulin resistance and metabolic syndrome.
The gut microbiome, not surprisingly, is most responsive to the composition of your diet. In one study, volunteers put on either a plant-based diet (grains, legumes, fruit and vegetables) or an animal-based diet (meats, eggs and cheese) for five consecutive days. At the end, the animal-based dieters experienced a significant decrease in their fibre-fermenting bacteria that produce butyrate, a protective substance maintaining intestinal wall integrity.
In other research, people in the obese category have been observed to show decreased anti-inflammatory bacteria and increased pathogens, leading to reduced butyrate production (the good guy.)
Another study has shown that rats fed a lard-based diet experienced a bloom of pro-inflammatory bacteria. In contrast, those fed a fish oil-based diet experienced blooms that are negatively correlated with obesity, type 2 diabetes and hypertension.
Other factors: our sleep patterns
While diet is the primary factor in the microbiome’s composition and behaviour, our gut is also sensitive to other environmental factors, which can increase the negative effect of those diets.
Modern trends, such as shift work and international travel, have allowed humans to manipulate their light/dark cycle. However, our body and its circadian clocks evolved in a natural light/dark cycle and still operates in this way, following the 24-hour rotation of the earth. Many of the body’s natural biological processes, including hormone release and blood glucose levels, show cyclical patterns every 24 hours. Interference with this cycle has been shown to promote obesity and affect insulin sensitivity and lipid metabolism.
Conversely, researchers also found that microbiome diversity was enhanced by increased sleep efficiency and time.
A high-fibre diet feeds the butyrate-producing bacteria, and butyrate nourishes the gut wall, which we have seen is vital in maintaining the balance of the body’s systems.
Plant-based food (vegetables and fruits) contain insoluble fibre, but the best food sources are chicory, asparagus, artichoke, leeks, onion, walnuts, cashews and pistachios nuts.
In addition, there is a range of therapeutic strategies that can also help.
The World Health Organization defines probiotics as “live microorganisms which, when administered in adequate amounts, confer a beneficial health effect on the host.”
Several studies have shown that probiotic strains, in particular those of the Bifidobacterium and Lactobacillus genera, deliver many beneficial effects, modulating low-grade inflammation, improving glucose tolerance and promoting weight loss and the reduction of visceral adiposity (the storage of fat around our vital organs).
Research further shows that Lactobacillus strains, especially those producing conjugated linoleic acid, contribute to weight loss, reducing the adipose tissue mass, as well as improving glucose tolerance and modulating the expression of leptin and fat storage.
Akkermansia is another bacteria that has also been shown to lower body weight in humans and rodents. First, its administration to obese mice improved insulin sensitivity, metabolic endotoxemia and adipose tissue inflammation. Further, a sole purified membrane protein of that strain was able to improve metabolism and gut barrier function in obese as well as diabetic mice.
Supplementation of the above microbes in humans improved insulin sensitivity and reduced levels of inflammation, with variable effect.
We define these as non-digestible polysaccharides that promote “the selective stimulation of growth of one or a limited number of microbial in the gut microbiota that confer(s) health benefit to the host.”
The most studied prebiotics are inulin (derived most often from chicory) and various types of fructo-oligosaccharides, which enhance the growth of beneficial bacteria such as Bifidobacterium or Lactobacilli.
Prebiotics can modify the gut microbial composition, enhancing the development of beneficial bacteria like Bacteroides, Prevotella and promoting the relative decrease of Firmicutes.
They also help to reduce body weight, body fat by modulating food intake and appetite and, at the same time, by decreasing fat storage.
Furthermore, the improvement in the gut wall’s integrity – and the decrease of pro-inflammatory cytokines release – naturally reduce low-grade inflammation and leads to an improvement of glucose tolerance and insulin sensitivity.
Fermented food carrying a far wider variety of beneficial microbes than probiotics; examples include yoghurt, kefir and sauerkraut.
Fermentation increases the level of B vitamins in your food and removes toxins and undesirable food constituents.
The diversity of your microbiome is key to your overall health. Eating fermented food is one way to increases the diversity of the live bacteria in your gut.
How much? Consuming a small amount of fermented food regularly is better than a large amount once a week.
To increase the diversity of your microbiome, you can consume a variety of fermented foods such as yoghurt kefir, sauerkraut, and kombucha; or choose a fermented food that has multiple microbes such as kimchi.
Making fermented food is fun but also beneficial, as your hands get covered in microbes too.
Fermented food helps weight management, prevent obesity and diabetes.
Faecal Microbiota Transplant (FMT)
Research has shown that the transfer of microbiota from lean donors to obese individuals with metabolic syndrome led to an increase in insulin sensitivity and in butyrate-producing bacteria within six weeks. However, a follow-up study that extended the observation period to 18 weeks revealed that the gut microbiota composition and insulin sensitivity had returned to baseline levels.
FMT is a promising remedy for metabolic syndrome but requires further verifications.
So, my friends, you can see that, whilst we must admit that study of the gut microbiome is still in its infancy, there is a significant amount of evidence linking the state of your gut microbiome with your risk of metabolic syndrome. Not only that, but there is good reason to believe that, whilst lifestyle changes can have the most far-reaching effect on your health, the administration of dietary modulations and therapeutic supplements can be a quick and easy “win.”
Don’t worry too much about the long names of the probiotics and prebiotics mentioned above – suffice to say that, at the Vitality Clinic, we can recommend the right doses of the right supplements for your specific needs.
Please do share your thoughts and questions by commenting on this piece, and do subscribe to the newsletter so that you don’t miss further vital information. Thank you!
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