Australia's Therapeutic Goods Administration (TGA) has granted approval to a fecal transplant therapy designed to target a serious bacterial infection. The approval marks the first time any regulatory body in the world has formally authorized this kind of microbiome therapy.
Although there is a massive amount of research currently investigating fecal transplants for the treatment of everything from alcoholism and obesity to skin cancer and autism, the idea of microbiome-modifying therapy is still incredibly nascent. The trillions of bacteria living inside our gut certainly play a role in our general health but exactly how to translate that knowledge into specific clinical treatments is still deeply unclear.
A fecal transplant is exactly what one would expect it to be. A healthy donor supplies feces, which are then formulated into either capsules or enemas for a patient to consume. The goal is to populate the patient's gut microbiome with healthy beneficial bacteria.
But simply taking one person's poo and giving it to someone else is a particularly blunt and imprecise way of modifying a microbiome. It's not like a universal, consistent source of poo can be generated from hundreds of different donors, each with unique microbial populations. So how do we create standardized fecal transplants that can be given to large volumes of people the same way we would administer a conventional medicine?
Because of this uncertainty, no regulatory body in the world has gone so far as to specifically authorize a fecal transplant therapy. In the United States, for example, the Food and Drug Administration (FDA) informally allows clinical uses of fecal transplants under a provision called "enforcement discretion." This means if a patient can supply their own source of "healthy" fecal matter then a doctor can oversee the administration of a fecal transplant and the FDA will not chase up any violation.
However, no single company is currently allowed to produce and market a microbiome-therapy with claims it treats particular conditions. A recent FDA advisory panel recommended approval of a microbiome therapy, similar to the therapy just approved in Australia.
Australia's TGA has given approval to biotechnology company BiomeBank for its "microbiome-based therapy product" dubbed BIOMICTRA. The therapy is very specifically approved only to treat infections from Clostridioides difficile bacteria, commonly referred to as C. diff.
This bacterial infection can take hold in patients following antibiotic treatments and leads to severe diarrhea that can occasionally be life-threatening.
BiomeBank has cultivated a collection of "super" donors, young and healthy people who regularly attend the company's facility to deliver fecal samples in custom-designed toilets. The samples are then processed into syringes, frozen, and delivered to clinical facilities for administration via either colonoscopy or enema.
Speaking to The Guardian, BiomeBank's chief technology officer Sam Forster said the company is working on a capsule-delivery system but the current method of delivery, and the one approved by Australia's TGA, is delivered by a doctor during a colonoscopy.
“The advantage of delivering during a scope is that you can get a large amount there very quickly,” Forster explained. “If you took it as a pill or a capsule, it would have to pass through the upper gastrointestinal tract to get to where it wants to live. You definitely don’t want a chewable tablet. Your problem is the volume – if you’re trying to put a few hundred milliliters of fecal material … that’s probably a normal glass size. You wouldn’t want to deliver it that way.”
BiomeBank is already looking to a future of fecal transplants beyond having human donors supplying poo samples. The company is building a collection of bacterial strains in the hopes of creating cultured and standardized microbiome-transplants.
"… we are excited to progress the development of our cultured microbiome-based therapies with the aim of alleviating microbiome mediated disease on a much larger scale," said Sam Costello, co-founder of BiomeBank. "It’s an exciting time for the microbiome field and we are pleased to be pioneering new solutions to treat these diseases."
BiomeBank is not the first group to look to a future of artificially cultured microbiome transplants. A recent study from a team at Stanford University demonstrated the first successful fecal transplant in mice using a microbiome built from 104 different bacterial species chosen to resemble an optimal healthy gut bacteria population.
Source: BiomeBank