I am in the throws of writing my next book all about how what we eat dictates our gut microbes, which has a HUGE bearing on our brain funciton. It’s an absolute labour of love, I’m still a long way off, but I thought I’d share a little of what what I’ve been working on today. So, as you may well know from my previous book “Why Eating Less & Exercising More Makes You Fat” our gut bacteria are controlling virtually all systems in the body. This highly complex colony of many species of bacteria, yeast, viruses and other weird and wonderful microbial bodies, collectively known as the gut microbiome, need to eat to thrive. Their fuel is fibre. If we feed our gut bugs fibre, they support many aspects of our healing, regulating and metabolic processes – hence they are called commensal, they are helping us out, big time.
There are a lot of different types of fibre and a wide range of fibre is essential to ensure we provide the correct kind of fuel to the many different microbes in the gut. The more diverse our fibre-based foods, the more likely we are to have a diverse gut microbiome. Although there is still much to learn about the gut microbiome, a common consensus amongst the experts is that the more diverse these microbes the healthier we tend to be. So, a wide range of different plant-based foods to include vegetables, some fruit (not too much as it is a largely a high sugar food, which can feed the wrong kinds of gut bugs), nuts and seeds, beans and lentils. Grains are a source of fibre too, especially wholegrains, but they can be problematic for other reasons, so brown rice, pasta, bread, etc. aren’t the best option for some.
The big daddy of gut microbes, or more technically speaking a key stone species, meaning it is highly influential on all aspects of human health and plays a positive role in which other species thrive in the gut, is Akkermansia Muciniphila (AM). Before you rush out and try and buy this incredibly important gut bug in a bottle, I only know of one producer of AM in a probiotic supplement form – an American company that has thoroughly research AM in its beneficial role in blood glucose and insulin management, hence their very specialised probiotic product is targeted at the type II diabetes market. It is very expensive, hard to get hold of and better yet, we can grow our own.
Akkermansia thrives on plant compounds called polyphenols, especially those found in pomegranates and cranberries – but before you go out and start consuming lots of juice from these fruits, read on. The polyphenols found in the purple, red and blue foods like berries, beetroot, carrots, tomatoes, red cabbage are all supportive of AM growth. Additional foods key for feeding these highly beneficial microbes are those that are bitter-tasting, also high in polyphenols, such as those found in good quality coffee; tea, especially green tea and in particular Matcha green tea; raw cacao / high cocoa content chocolate; peppery, cold pressed olive oil; black cumin seed oil and bitter leaves like radicchio, rocket (arugula), endive, and some red wines. As the good microbes and in particular Akkermansia consume these polyphenols, they produce important compounds that fuel other microbes which then produce further compounds known as post biotics, that help us heal and thrive.
So, prebiotic fibre from plants feed our probiotic microbes, especially polyphenols for AM, and the result is an increase in post-biotic production of short chain fatty acids that heal the gut lining, provide energy for our cells and even help boost brain function. That my friends is a massive win, win, win!
Akkermansia Muciniphila lives in the mucin of the gut wall, which is the slimy, gloopy lining that covers the entire digestive tract from top to literally bottom. It helps food and stool move through the system; it acts as a highly protective barrier to the delicate cells of the gut; it supports immune function and it houses big daddy Akkermansia. Akkermansia needs to be fed those fibre-rich, brightly coloured plant foods, as explained above, but it will also quite happily munch away on the mucus lining it calls home. This has tremendous benefit to us as its human host because the eating of the mucin means that the cells in the gut that make the mucin are stimulated to make fresh, perky mucus on a regular basis. It’s a cleaning up and refreshing system that we benefit from. AM will only achieve this if we go for periods of time when we don’t eat, hence a great reason to not be snacking between meals and to leave a good fasting window from last calories to first calories the next day. A minimum of 12 hours up to around 16 hours a few times a week can be enough to achieve this mucus-munching benefit. However, as with all aspects of health, there’s the Goldilocks Sweet-Spot and too much fasting could result in too much minching away of your mucin lining, potentially leading to inflammation and damage.
Something I’ll be exploring in more detail in my new book is the use of prebiotic fibre supplements to take during a fast in order to feed the microbes, including Akkermansia, especially if doing longer fasts, while not actually feeding oneself.
Good foods to consume to support your other gut microbes are the foods high in prebiotic fibre and resistant starch such as pale green bananas, rather than ripe bananas; cooked, cooled and reheated potatoes of all kinds, including sweet potatoes (this also applies to cooked and cooled rice but be very careful as cooked rice needs to be extremely well re-heated to ensure it is safe to eat); Jerusalem artichoke, onion, garlic and leeks are all also very high in special fibre types that the gut bacteria love as are beans and lentils – but cook them extremely well, ideally pressure cook to make them more digestible.