Monday, 23 May, 2022
HomeTalking PointsSuper poo: The emerging science of stool transplants and designer gut bacteria

Super poo: The emerging science of stool transplants and designer gut bacteria

As more people turn to faecal transplants for their health benefits, researchers are harnessing the power of high-quality poo in new treatments that can simply be swallowed, reports The Guardian Australia.

Good poo donors are so hard to find they’re sometimes called “unicorns”. These elusive, healthy creatures service a market for faecal transplants that is growing rapidly as evidence of its benefits mounts. Now researchers are working on a “super stool” – a poo pellet you can eat that mimics a so-called unicorn’s special abilities.

Emerging science shows that a human’s microbiome – their constellation of gut microbes – has a far greater effect on health than anyone previously imagined. The collective genetic material in the microbiome performs myriad functions that affect our mood, our immunity, and our physical and mental health.

Crappy western diets and antibiotics are depleting our microbiota.  Restoring them to health has become a serious scientific endeavour, as the diversity of our gut bacteria is linked to everything from depression to how we respond to cancer treatment.

The transfer of healthy stool into the gastrointestinal tract of an unhealthy recipient has been proven to treat people with intestinal conditions, including the superbug Clostridium difficile colitis (C diff ), which can cause diarrhoea, sepsis and even death.

Replicating unicorns

BiomeBank’s office is in the suburbs of Adelaide.  The biotech company is home to a stool bank – and it’s a place where designer poo transplants are made.

There’s a special donor room (a glorified toilet) where poo donations are received. There’s a lab with an anaerobic work station, where donors’ bacteria strains are put into a “secret sauce” to grow and then isolate strains. Those strains are categorised and catalogued for future use.

BiomeBank’s head of donor screening, Dr Emily Tucker, says there’s a long list of requirements for a stool donor. They have to be healthy, obviously. They have to be screened for infections. A detailed history of their medical, travel and antibiotic history is taken.

Those who make it through all the assessments are enrolled for an eight-week programme where they have to turn up on time, fill out a questionnaire, then (ahem) make a deposit inside a special room.

So what happens if there aren’t enough unicorns? That question inspired BiomeBank’s latest endeavour – to replicate the contents of a unicorn’s guts.

The poo factory

People are building libraries of the very best that poo has to offer, and BiomeBank is part of the effort to categorise premium stool strains.

Costello, a gastroenterologist, says that humans historically had much more diverse microbiota. We lived more closely with other people and with animals, and we ate more unprocessed food.

There’s evidence, he says, that this depletion is evident across society – particularly western society. He describes a “microbial extinction event” in the modern world. As on earth, so it is in our intestinal system – we’re living with the consequences of a hollowed-out ecosystem.

Mitchell explains that in BiomeBank’s first generation of microbial therapy they extracted the right bacteria, freeze-dried it and put it in a capsule.

Patients can take it orally to treat specific infections. This generation has already been rolled out in hospitals, and, if approved by Australia’s Therapeutic Goods Administration, it will be the first microbial therapy in the world approved as a biologic (it currently has provisional approval).

Then there’s the second generation – a replication. Think of the unicorns as Adam and Eve types, but their genomic sequences can be reproduced. You can grow them. Isolate them. Identify them, name them, put them in a library, and gradually build up knowledge about what each strand can do.

And when you hit a vein of gold, a bacterial strain that sorts out a deficiency in someone’s microbiota, you scale it. Then you put it that bespoke bacterial recipe in a capsule that someone else swallows. “It’s a new way to treat disease,” Mitchell says. “It’s a little factory.”

Nutrition for better microbiomes

Prof Felice Jacka, director of Deakin University’s Food and Mood Centre, is a nutritional psychiatrist (and the author of There’s a Zoo in My Poo, which features recipes for “better bog burgers”, “farty toast” and “zoo poo stew”). The centre examines the “mindbogglingly complex” links between diet, gut and brain health.

“You have all of these organisms that interact with each other in a way that’s impossible to map at this stage,” she says. “We’re still really at the beginning of working out what microbiota can do.”

And Jacka’s a fan of the “super stool” plan, not least because “giving people other people’s shit” has a bit of the icks about it. “It’s absolutely worth doing,” she says. “Finding those super donors is hard. Only about 3% of people qualify … Those super poopers are kind of rare, so it you can distill that, if BiomeBank can come up with a stool equivalent, it’d be awesome.”

According to The Guardian, there are dozens of studies under way in Australia, but existing research has already shown that a bad diet, like the standard American diet, leads to increased inflammation in the body, which means a higher risk of cancer.

A team from the Imperial College London and the University of Pittsburgh compared African Americans to rural South Africans. The volunteers were tested, then swopped diets and were tested again.

After just two weeks on the fibre-rich rural diet, the Americans had significantly less colon inflammation and a lower cancer risk. Unfortunately, the rural group went the other way.

Cancer and the gut

The Food and Mood Centre is studying nutrition and its effect on depression, on muscle and heart health, on psychotic disorders, on post-traumatic stress disorder, eating disorders and a host of other health concerns. Jacka nominates cancer research as one of the most exciting fields in microbiome studies. Data show better responses to treatment, particularly immunotherapy, in people with more diverse gut microbes.

But she warns that much research is still nascent, and that industries out to make a buck are capitalising on it too quickly, selling products with vague promises of promoting “gut health”. “Be aware, keep an open mind, but not so open your brain falls out. Or your wallet, more to the point,” she advises.

Helping the gut

At this stage, poo transplants are only recommended, or useful, in very specific cases. But everyone can improve their microbiome, and you don’t need supplements, writes The Guardian. Jacka says for most people, changing their diet is enough to change their bacteria.

Eat lots of plants, different types of plants, different-coloured plants, and throw in some fermented foods.” Think kimchi, kombucha and sauerkraut. And think fibre.

Jacka says that with typical western diets your gut microbiota is so “weak, wan, pale and deficient” that it just can’t cope with fibre. Then when people try to incorporate more roughage, they get gas or a stomach-ache. Some people then mistakenly think they have irritable bowel syndrome or a gluten intolerance, and back off the fibrous foods.

You have to start gently, she says. Increase the amount and type of fibre gradually. “The answer to a problem with beans,” she says, “is actually more beans”.


The Guardian article – Super poo: the emerging science of stool transplants and designer gut bacteria (Open access)



See more from MedicalBrief archives:



Faecal transplant shows potential as treatment for autism



The war over faecal microbiota transplants



Updated guidelines for treatment and care of Clostridium difficile



Gut microbe metabolism implicated in longevity — Japan study of centenarians



Babies' gut bacteria affected by birth delivery method


MedicalBrief — our free weekly e-newsletter

We'd appeciate as much information as possible, however only an email address is required.