Gut health is a huge and very complex subject, and I am going to cover just some of the basics in this blog post (although I could easily write a book about it!). There is a lot of talk about bacteria and viruses at the moment, and they are generally perceived as bad. There are however some “good bacteria” too, especially when we talk about our gastrointestinal tract, or gut – the system of digestive organs.
The digestive system is so much more than just one long mucous-lined tube for our food to pass through in its various stages, with a lot of studies and ongoing research in regards to the link between gut health and the immune system, mental health, skin conditions, cancer and autoimmune diseases to name just a few.
Gut microbiome
The widely spread term “gut microbiome” refers to the microorganisms living in our intestines, and each of us has many trillions (yes, that’s correct – trillions!) of bacteria from up to 1000 different species in our digestive tract. Some microorganisms are indeed harmful to our health but many are beneficial and even essential to our overall health and survival.
When we talk about gut health we in effect refer to the balance of microorganisms that live in the digestive tract. Maintaining the right balance of these microorganisms and looking after the health of the gut is vital for our health and our immunity.
We are first exposed to microbes when passing through our mother’s birth canal, although new evidence published a few years ago suggested that babies might come in contact with some microbes while inside the womb. Our gut microbiome diversifies as we grow and as our diet and environments alter, and the higher the diversity in the microbiome the better it is for our health.
The food we eat affects the diversity of our gut bacteria, we really “are what we eat”.
Immune system, gut-brain axis and serotonin
Put simply, the gut bacteria help break down the food we consume and turn nutrients into things our body can use. The “good” bacteria also help keep the “bad” bacteria in check, preventing the unhealthy kind to grow – ideally we are looking for a healthy balance of bacteria in our gut referred to as “equilibrium”.
You might have heard the term “gut dysbiosis” – this is an imbalance of gut microbes.
Over 70% of the immune system cells are based in the gut, and many studies link a poor diet to an imbalanced microbiome and the way our immune system deals with viruses and bugs for example.
Besides the brain the gut is the only organ with its own nervous system – the enteric nervous system, which also acts as a second brain. The gut-brain axis is fascinating. It consists of bidirectional communication between the central and the enteric nervous system, involving direct and indirect pathways between cognitive and emotional centres in the brain with peripheral intestinal functions.
And to give just one more example, the majority of the body’s serotonin, the hormone that affects mood and sleep, is produced in the gut, and every class of neurotransmitter in our brain also resides in our gut. This explains why, in order for the brain to be in balance the gut must be in balance!
It quickly becomes clear why so many conditions and health concerns are linked to the gut. With many clients I work on addressing their gut health first, and often this leads to major improvements in their general health and wellbeing despite digestive symptoms not being their main reason to see me. As mentioned previously and as is a key principle of Nutritional Therapy – everything in the body is interconnected, and we often need to address a multitude of factors and get to the root of the health concern before seeing an improvement. With the gut being linked to so many things in the body it’s no surprise that it’s often a good starting point – gut health literally affects the entire body.
So back to our gut, and to the bacteria mentioned above!
Prebiotics, Probiotics & Synbiotics
You have probably seen or heard about “prebiotics” and “probiotics”. Probiotics are the live “good” bacteria in our gut, whilst the prebiotics are a food source for the probiotics, meant to promote the growth of beneficial bacteria in the gut. Prebiotics are in fact non-digestible carbohydrates, which encourage the beneficial bacteria to multiply in the gut.
There are both prebiotic and probiotic food sources:
- Prebiotics:
Garlic, onions, asparagus, leeks, bananas, Jerusalem artichokes, chicory, whole grains
- Probiotics:
Fermented foods such as kimchi, sauerkraut, tempeh, miso, and kefir are great dietary sources of probiotics, as are dairy products like natural yoghurt and aged cheeses (check the ingredients list for live cultures of bacteria like bifidobacteria and lactobacilli).
When prebiotics and probiotics are combined it’s called a synbiotic, which is said to help probiotics live longer. Think of synbiotic combinations like bananas and yogurt, or stir-fry asparagus with tempeh! Fascinating, right? Let me know what other ideas you come up with!
Generally speaking, a diet high in processed foods and added sugars can decrease the amount of good bacteria in your gut, as can high stress levels, lack of sleep and taking antibiotics.
More details about the gut-brain axis in a future blog post, as well as common signs of an unhealthy gut and further tips on how to improve your gut health!
And just a quick note about probiotics – there is a huge range of probiotic supplements on the market, across a wide price range. Please don’t rush to your nearest health store to buy some probiotics – there are many different strains and varying qualities, and in order to make a difference to your wellbeing we need to make sure you take the ones that are beneficial for you. Our gut microbiomes are unique, and anyone suffering with bacterial overgrowth, such as SIBO, should not take probiotics.
Also watch the sugar content in some of the commercially promoted “healthy” drinks containing live bacteria or probiotics.
Thank you for reading, and keep well!
