“All disease begins in the gut” goes the immortal phrase of Hippocrates, the father of modern medicine.
Thousands of years on, the latest research is proving he was right, and that many of the lifestyle diseases that plague us are hugely affected by the bacteria that live in our stomach.
So how do you make sure you have enough of the ‘good’ ones?
Women have long worried about the state of their stomachs, but in recent years the number one cause for concern has been its internal workings, not its aesthetic appeal.
Gut health is becoming a priority as the link between what we eat and how we feel becomes increasingly apparent. The growing popularity of bone broths, probiotics and fermented foods in cookbooks and eateries shows we’re all becoming aware of how great a part our gut health plays not only in our current wellbeing, but also in our ability to prevent or reduce the impact of disease in the future.
Enter the microbiome
In simple terms, the microbiome is all the micro-organisms that live in and on the body and is completely individual to each of us. There are trillions of different types of bacteria in our systems, and up until recently, we only knew about some of them.
In 2008, the Human Microbiome Project was established to investigate what makes up our microbiome, and how it affects our health. And that’s where things got interesting.
“Our perspective has shifted because in the past decade we’ve realised that not only are these microbes not harmful, they’re essential for good health,” says Dr Robynne Chutkan, author of The Microbiome Solution, on the phone from her home in Washington DC.
“They synthesise vitamins we can’t create, they detoxify compounds, they turn genes on and off, and most importantly, they train our immune system so it doesn’t overreact to things it shouldn’t.”
This is one half of Chutkan’s ‘Live dirty, eat clean’ message: we’ve become so overcautious about germs that in the process of super-sanitising our environment, we’ve been throwing the baby out with the bathwater and killing all our good bacteria alongside the bad.
“If you [look at] the rise of hand sanitisers and antibiotics in the past century, you see also the climbing rates of obesity, autoimmune disease, allergies, asthma and all these other things that we think are at least partly related to these missing microbes,” says Chutkan.
“Think of the things we take for granted, like chlorine in our drinking water – it’s great for preventing cholera outbreaks, but not so good for preserving your microbiome because chlorine is very antibacterial.”
Messing with the process
In 2010 the International Scientific Forum on Home Hygiene released its findings from a study into the rise of chronic inflammatory diseases (CIDs) such as type 1 diabetes and multiple sclerosis, saying they “seem to stem from impaired regulation of our immune system… deficiencies in microbial exposure could be key to rises in both allergies and CIDs”.
In the past 30 years, the rate of autoimmune diseases worldwide has climbed by 5-7% a year; we’re getting sicker, and yet we have better access to medicine than ever before.
Chutkan believes the overprotection of our immune system is part of the issue, citing a study from the London School of Hygiene & Tropical Medicine in the 1950s that looked at the then skyrocketing rates of asthma and eczema in industrial London.
“They found that kids who came from large families, where some sibling was always sick, had very low rates of asthma and eczema, and kids who came from affluent households, where people were washing all the time, had very high rates. We see a similar thing where a lot of autoimmune diseases are more common in affluent households. If you see how kids interact naturally, they’re rolling around in dirt and putting it in their mouths. They’re helping cultivate microbes in their body and we should not interfere with that process.”
Environmental triggers
The term ‘autoimmune disease’ refers to conditions in which the immune system starts to attack healthy tissue instead of invaders.
There’s a huge range of illnesses that fall under this umbrella – everything from digestive system issues such as Crohn’s and coeliac disease to more systemic conditions like multiple sclerosis and lupus. It’s a major problem affecting the developed world – it’s estimated that 50 million people in the US alone have an autoimmune disease – and, says Chutkan, it turns out most of these diseases have a “microbial contribution, if not origin”.
“Even with diseases like Parkinson’s, they’re finding out that there is a genetic predisposition but the trigger is often an environmental one.”
Chutkan believes that the ramifications of this could be hugely positive for the future of both treating and preventing disease.
“We can’t change our genes, but we can change our microbes. The microbes you go to bed with tonight are not the same ones you’re going to wake up with tomorrow,” she says.
“I think it’s incredibly optimistic for people who struggle with chronic problems, serious diseases like Parkinson’s, or even many forms of cancer, which we’re now finding out have a microbial component.”
All the feels
The gut microbiome is also responsible for secreting and regulating hormones, and is associated with the enteric nervous system, which is embedded in the lining of our gastrointestinal tract and has been dubbed ‘the second brain’.
In fact, about 90% of our body’s serotonin – the ‘feel-good’ hormone – lies in our gut. The expression ‘butterflies in my stomach’ is more than words – it’s a biological phenomenon.
The type of bacteria that live in your gut can therefore have a dramatic impact on your mental health.
“There have been studies where they’ve transplanted bacteria from anxious mice into germ-free mice, and then those germ-free mice – once they’ve acquired those microbes – become anxious,” says Chutkan.
“It’s the same thing with obesity – certain microbes are better at extracting calories from foods than others, and when you take the microbes from obese mice and transplant them into lean, germ-free mice, they gain weight without any changes to their diet. A lot of these things – not just disease, but emotion: anxiety, depression, aggressive behaviour – seem to be in large part influenced by what your microbial composition looks like.”
The ultimate probiotic
We all know the benefits of probiotics such as yoghurt containing live cultures for introducing healthy bacteria to our gut, but they do have their issues – shelf life, viability and dosage among them.
The future of probiotics takes the concept to the next level in the form of faecal microbiota transplantation (FMT). Yes, that’s exactly what it sounds like: faecal matter from another person can be inserted into your body to expose you to new, beneficial microbes.
Before you start thinking that sounds too far-fetched to be true, Chutkan says it’s rapidly becoming one of the most-requested procedures among her clients.
“When you get a stool sample, you know it’s fresh probiotic every time. There are over a billion microbes in one drop of fluid in your colon alone, so think about how much is in a can full of stool,” she says.
“The downside is you’re also potentially getting toxins in the stool, and some bad bacteria, and DNA material that can get incorporated into your own DNA. The benefit [of FMT] has to be worth the risk.”
The future is faecal
As queasy as the idea might make you, the more we learn about the impact of gut health on our overall health, the more appealing the possibility of altering our microbiome for the better and recovering from related illnesses becomes.
In The Microbiome Solution, Chutkan goes into at times eye-watering detail about how to select the right FMT donor and test that the stool sample is of the highest quality.
She believes samples from those who are non-Western born are ideal: minimal antibiotic use, a plant-based diet, locally grown food, no chlorine in the water.
“The typical American kid has had about 18 courses of antibiotics by the time they graduate high school; in many ways someone from the developing world – once you’ve excluded infection – can be a really good donor,” she explains.
“We’re going to be seeing some of these tissue banks in the future. Depending on what kind of condition you’re trying to fix, you might get a stool that’s rich in one bacteria if you’ve got traveller’s diarrhea, or you might get stool that’s rich in another type of bacteria if you’re trying to clear up eczema. I think that’s where we’re heading in the very near future.”
Words: Emma Clifton
