The Gut Biome
Your true route to great health!
Scientists are only just discovering the enormous impact of our gut health and how it could hold the key to everything from tackling obesity to overcoming anxiety and boosting immunity. If you want to learn more about what’s going on in your gut, the first step is to turn your poo blue, a bit gross I know. How long it takes for a muffin dyed with blue food colouring to pass through your system is a measure of your gut health: The average should be about 28.7 hours, longer or shorter times are a good indication that somethings not right.
We are only now beginning to understand the importance of the gut microbiome: could this be the start of a golden age for gut-health science?
“The gut microbiome is the most important scientific discovery for human healthcare in recent decades,” says James Kinross, a microbiome scientist and surgeon at Imperial College London. “We discovered it, or rediscovered it, in the age of genetic sequencing less than 15 years ago and for all that the internet may be full of probiotic or wellness companies making big health claims about gut health, we don’t really know how it works,” he says.
At the risk of sounding like the late Donald Rumsfeld, there’s what we know, what we think we know, and an awful lot that we don’t yet have a clue about.
The Numbers:
Your gut microbiome weighs about 2kg and is bigger than the average human brain, the only organ which is bigger is the liver, yes we now call it an organ and the numbers just get even more magnificent.
It’s a bustling community of trillions of bacteria, archaea, fungi and viruses, containing at least 150 times more genes than the human genome. We have about 400 trillion human cells in our bodies and about 650 trillion cells in our gut biome. Yep! In the numbers game we are actually more gut biome than we are human.
We are filled to the brim with microbes, which form microbiomes on our skin, in our mouths, lungs, eyes, and reproductive systems. These have co-evolved alongside us since the beginning of human history. But the gut’s is the largest and most significant for our short and long term health. It’s massively complex and its residents vary enormously from person to person. According to a study in 2020 by the European Bioinformatics Institute, which pooled more than 200,000 gut genomes to create a genetic database of human gut microbes, 70% of the microbial populations it listed, about 2,000 species, and these had never been cultured in a lab and were previously unknown. In other words a whole new strain of microbes.
It’s a vital organ in your body and you need to look after it, If you do that, it will look after you. The fact that the gut microbiome can be considered an organ is still up for discussion in some circles, many microbiome scientists call it an organ, given that it is both inherited and essential, while others use the title superorgan, because of it’s supreme importance.
Lots of things that people don’t think about, like depression or anxiety, are very clearly modified by your gut microbes. Appetite and ability to digest food are modified by gut microbes and the recent key finding is the link with the immune system. Basically the gut microbiome is controlling it, gathering feedback data and sending signals around the body. Because most of your immune system is in your gut helping you to fight infections such as Covid and early cancers.
Studies suggest having a diverse population of gut microbes is associated with better health but when human populations urbanise, microbial diversity declines. Over the past 80 years and since the dawn of antibiotics, there has been multi-generational loss of microbes that appear to be important for human health. They’re passed from mother to child, during birth, via breastmilk and skin contact from the time we’ve been on earth but at some point in the last three or four generations, we lost some. We’re not entirely sure if the cause was our lifestyle, our diet, cleanliness in our homes or the use of antibiotics. But what is absolutely certain is that these are still present in the developing world.
What are the implications of this? Well, it may account for, and it could be the underlying factor that a large proportion of the chronic diseases in our society such as: asthma, food allergies, ME, cancers, atopic diseases and auto immune disorders are massively on the increase. It’s difficult to prove epidemiologically, but 100 years ago no one bothered about allergic diseases because globally 50m people a year were dying of infectious diseases, but over the past 50 years of good scientific record keeping, we’ve seen a significant increase in those disorders alongside this loss of microbial diversity in our guts.
Gut microbes do things the gut can’t do, liberating or synthesising nutrients from food, especially from plants, making vital short chain fatty acids that are involved with immunity, with keeping the gut and colon healthy, with moderating the body’s inflammatory responses and with the metabolism of glucose. To do this, microbes need about 30g of fibre a day, but the average intake in the UK is just 10 to 15g. Is this why modern, low fibre, ultra processed, high salt and sugar diets seem so problematic for human gut health?
It’s very hard to know exactly what it is in junk food that is causing a problem, it’s not necessarily the fat, carbs and protein, but is more likely to be the extra chemicals in the ingredients. The data is probably best for artificial sweeteners that are derived from things like paraffin and the petrol industry, so our bodies and our microbes are not used to breaking them down. But it could also be the other stuff that’s included, like the enzymes that aren’t detailed on the label, or even the emulsifiers. There are few studies on emulsifiers, and nearly all of these are in animals, but they show that you get reduced diversity and more inflammatory microbes. The idea is that they’re doing the same as they are in cooking: sticking your microbes together, creating an emulsion and glooping up our systems.
So if our microbes are so important can’t we just package up the right ones and put them in a pill? Professor John Cryan is chair of the department of anatomy and neuroscience at University College Cork and principal investigator at the APC Microbiome Institute. “We will get strains of bacteria to have beneficial effects,” he says, but he laughs when I ask him how he feels about probiotics. “That’s like asking me, ‘Do I like drugs?’ If I have a pain in my head, I want to take a drug that has efficacy for headaches. I wouldn’t just randomly pick one. But that’s what we’re doing with probiotics right now. The science needs to catch up. We’re lumping them together as if they’re the all the same thing, but, like drugs, they may do very, very different things. We need to get precision into probiotics and then I can be excited about them. But most of what’s out there is complete nonsense.”
While many microbiome scientists don’t have much time for the commercial probiotics industry, there is growing interest in what are now called live bio-therapeutics, probiotics designed and tested to be used clinically (none are yet licensed for medical use in the US or Europe). Professor Ingvar Bjarnason is a gastroenterologist who has conducted double-blind, placebo-controlled studies on specific probiotic blends. “There is no data whatsoever for the vast majority of the probiotics on sale,” he says. But he is curious about a blend he has already studied for its impact on IBS, called Symprove, and its potential as a treatment in hospitals for acute Covid. “We think of Covid as a virus of the lungs, but the microbiome of people with acute Covid can be altered very severely. Very ill people with Covid have a cytokine storm where they have multi-organ failure, due to an enormous amount of really strong inflammatory markers. The suspicion is this inflammation may come from the gut, and when the gut has been examined in acute Covid patients, it is massively abnormal.”
Lumped in with commercially available untested probiotics are the so called “health yogurts” and drinks that claim to lower cholesterol, reduce weight and have untold health benefits. Non of these are particularly sympathetic to our gut biome and in a lot of cases could even be destructive due to the fact that they are processed, not fermented, dairy products made from pasteurised milk and are full of sugar.
The final frontier for gut microbiome exploration is its relationship with our brains, something the new fields of nutritional psychiatry and psychobiotics are researching into. We already know the gut has its own nervous system, the enteric nervous system, and contains 100m neurons. We also know the gut-brain axis, via the vagus nerve, shoots neurotransmitters produced within the gut around the body and to the brain, which is why a huge research project has studied the impact of particular bacteria on sleep and how certain types of fibre can improve complex cognitive processes.
Kimberley Wilson is a chartered psychologist and author of How to Build a Better Brain. She uses nutrition as part of her treatment plans. “The short-chain fatty acids produced from microbial fermentation of fibre in the gut are quite similar to some mood-stabilising prescription drugs,” she says. “Some of the association that we see between healthier diets and better brain health could be because your microbes are producing psychoactive substances from your diet to help stabilise your mood. In the future, we might actually prescribe certain types of fibres for certain mental health conditions.” For now, she simply prescribes a lot more fibre to feed what many scientists now consider our second and much larger brain. “The more fibre you eat, the more substrates the microbiome has available. And the better off we’re going to be, psychologically.”
All of the above just massively incredible and what we can conclude is that if you do nothing more than look after your gut biome your physical and mental health will absolutely be transformed.
In all of this research a few glaring facts are known and recognised by all the scientists to be the bedrock of a healthy gut biome: eating processed foods is massively destructive, just pumping the body full of probiotics can be as destructive as eating processed foods, the gut biome is equally important as our brain and eating fermented products is absolutely essential.
Next time I’m going to delve deeper into how to improve your gut biome and what to eat to compliment this delicate structure. I’m beginning to understand a huge amount about the gut biome and the relationship with fermented foods and have actually started to produce a small range of fantastic fermented foods and drinks.
If you’d like more information just e mail, message or WhatsApp and I’ll get straight back to you.