The new frontier in gut health
RESEARCHERS HAVE FOUND A REVOLUTIONARY NEW WAY TO POPULATE OUR GUT WITH HEALTHY BACTERIA… BUT IT’S NOT FOR THE FAINT-HEARTED. SARA BUNNY GETS THE LOWDOWN
The new frontier
In a world where fermented food, probiotics and ‘good bacteria’ have become buzzwords, everyone from your hairdresser to your workmate’s second cousin is talking about gut health. Over the past few years, we’ve heard about how to boost our flora, maximise our microbiome, and how the hotbed of highly sensitive bacteria we all host in our digestive tract can influence everything from our mood to our immunity.
But in specialist labs across Australia, New Zealand and further afield, scientists are unlocking a brave new frontier in gut health, and it’s all about... faeces. Whether you see it as revolting or revolutionary, gut microbiome transfers – where a stool sample from one person is implanted in another – have health experts intrigued. There’s a lot more work to be done, but some researchers are already saying they could help to treat everything from chronic illness to obesity.
Tiny microbes, huge impact
While these transplants have only recently been part of formal lab studies, the concept is said to date back to ancient Chinese medicine. The transplants were carried out in the Western world in the 1950s, but a combination of a lack of modern technology and general squeamishness meant it wasn’t something that spurred widespread interest – until now.
A gut microbiome transfer or (GMT) involves, in cut-to-thechase terms, taking poo from one person, removing the waste and implanting it into another, via colonoscopy, an enema, or as a (tasteless and odourless) capsule. The idea is that healthy bacteria from the donor then take up residence in the recipient, encouraging more good bugs to grow, balancing out harmful microbes and eventually restoring order to the digestive tract. In some clinics, it’s known as a faecal microbiota transplant, and while the concept might sound cringeworthy, it’s already more mainstream than you think. In some public hospitals and private clinics, the procedure is used to treat Clostridium
difficile bacteria, a severe, antibiotic-resistant infection that can wreak havoc on the bowel. So far, the number of patients treated with this procedure is still relatively small, but for this particular infection, GMT can give results after conventional treatments have failed. Some studies put the success rate at 90 per cent after a single procedure, and researchers from University of Alabama at Birmingham have found evidence to suggest that certain strains of donor bacteria have remained in the recipient’s gut for up to two years after the transplant.
However, whether it can be as effective for other conditions is still largely unproven. But it’s safe to say it’s a concept that has researchers the world over taking a closer look at the complex world of microbes.
At the Liggins Institute in Auckland, researchers are studying the way gut bacteria can influence obesity. The ‘gut bugs trial’ involves a group of 80 obese teenagers who are receiving microbial transplants from slim, healthy donors. The transplants are taken as a capsule
These have only recently been part of formal lab studies, but the concept dates back to ancient Chinese medicine
inside a second capsule, after the raw material has been thoroughly cleaned, and carefully screened for infectious bacteria. Research is still in the early stages, but study co-leader and professor of paediatric endocrinology Wayne Cutfield says science is steadily learning more about the tiny microbes we all share our body with.
“It’s an almost unbelievably fascinating concept that bugs in your bowel, that 10-15 years ago we thought were just chomping up waste, actually influence our health and wellbeing,” he says. “They release chemicals that interact with our brain, and they may actually influence our appetite and behaviour. They can also influence the risk of diabetes, obesity, and potentially the risk of heart disease, alongside allergies, eczema, and inflammatory bowel disease.”
Other studies into faecal transplants include research from the University of New South Wales that found enemas with healthy bacteria were effective for treating the chronic bowel condition ulcerative colitis, while doctors at the Melbourne FMT clinic claim the transplants can be used to treat Crohn’s disease and irritable bowel syndrome.
Some reports into the effectiveness of GMT suggest faecal transplants could benefit conditions that may be affected by the microbiome, like autism, multiple sclerosis and rheumatoid arthritis – although there have yet to be any studies to prove it.
With news of gut microbiome transfers appearing in everything from magazines and newspapers to social media and TV chat shows, some experts are now warning against getting caught up in the propaganda. Dr Justin O’Sullivan, who co-leads the gut bug trial at the Liggins Institute, says while theories sound interesting, it all comes down to solid evidence. “There’s a lot of hype around FMT, or GMT, and it’s all based on promise. The absolute proof that it works is absent at the moment, and that’s what
we’re trying to gain.”
But mapping trillions of bacteria is no easy feat, and it’s not clear yet which organisms give which particular health benefits. We each carry around our own personal cache of 3040 trillion microbes, equating to about 1.5kg worth of bacteria. Even more impressive is that while humans share 99 per cent DNA, two people may only have a 10 per cent crossover in their microbes.
This complex population of bacteria interacts in countless ways, and if the bad bacteria outnumber the good or the levels get depleted, this imbalance can lead to everything from severe gastro upsets and poor digestion, to allergies, yeast infections and fatigue. And variety counts. Experts agree that the healthiest microbiomes are those with the most diversity, but our gut flora is getting depleted – and modern lifestyles may be to blame.
In the book The Microbiome Solution,
Dr Robynne Chutkan says to “live dirty, eat clean”, meaning we should limit the use of chemical sanitisers, and not be afraid to get some dirt on our hands. She claims that while cleaning products might be effective for culling bad bacteria, they are killing off the good bugs too. “Harsh cleaners and antibacterial products super-sanitise our bodies and our already sterile environment, threatening the existence of what few microbes remain,” she says.
In the book The Clever Guts Diet, Dr Michael Mosley says widespread antibiotic use, chemicals in processed foods, and a limited diet are the key culprits.
“We eat such a narrow range of foods, so our gut bacteria have to live on a restricted diet,” Mosley says. “Of the 250,000 known edible plant species, we use less than 200. Seventy-five per cent of the world’s food
comes from just 12 plants and five animal species.”
To add to its complexity, part of our microbiome is developed long before we’re old enough to choose what we eat.
“The microbiome is populated in the womb,” says O’Sullivan. “You have certain genetic predispositions in your DNA, and certain sequences that are specific to you. It seems there’s a correlation between some of those variants and the presence of particular bacteria in your microbiome.
“It fluctuates quite a bit; it depends on what you eat, is influenced by all the surfaces you touch, it’s changing all the time. It’s an eco-system. It’s like if you water a certain plant in your garden, that plant is going to grow a lot and it’s going to shade other plants and prevent them from growing, and it will change the environment around it, and that’s exactly what happens in your gut.”
While scientists are still working on the proof that faecal transplants benefit the microbiome, one thing the experts agree on is that no amount of processed poo is going to cancel out an unhealthy lifestyle.
“Estimates say diet influences about half of the behaviour of the gut microbiome, and it’s about the bacteria that are there, but also which ones are busy,” says Cutfield. “So you can have a whole lot of bacteria there but if you’re feeding them crap, it’s a whole lot of bad bacteria that are going to be busy. Our microbiome is a product of our own genes, but diet and activity are powerful players.”