Fecal Transplants May Save Koalas From Starvation

June 2, 2023

Fecal transplants are currently being studied to treat a whole handful of human conditions but the potential of the unconventional treatment may have reaches beyond human health.

A new study suggests that fecal transplants may be able to save Australian koala bears from extinction.

The study which was released last month found that fecal transplants may help koalas expand the types of foods they can eat and digest, saving them from starvation. The study not only highlights the possible benefits for microbiome manipulation in koalas but it potential to help other species who are seeing similar extinction patterns.

We will cover the study and exactly how FMTs are being used to save koalas in the following sections.

  • Koala’s limited diet
  • How FMT can expand the koala palette
  • Other application for FMT in threatened species

It is first helpful to understand why the koalas are starving in the first place.

Koala’s limited diet

In 2013 the Koala population in Cape Otway, Australia climbed unusually high, which led to overconsumption and subsequent loss of the preferred food source (manna gum) of said koalas. Faced with starvation, researchers noted that the Koalas still would not eat from other eucalypts, which were available to them and were plentiful. In the following two years approximately 70 percent of the koalas in the Cape Otway region died, whittling their population down to less than 3,000.

The tragic and considerable decline of the koala population lead researchers to hypothesis why, despite availability, were the koalas not willing or able to eat the more plentiful messmate eucalyptus? Researcher Ben Moore of Western Sydney University suspected a possible microbiome connection. Perhaps their diet was limited, not because the Koala’s were picky but because they didn’t have the necessary bacteria available in their gut to properly consume and digest eucalypts other than the manna gum.

To test the theory Moore and a team of researchers collected the stool of koalas that fed solely on manna gum, as well as stool from koalas who were also able to feed on messmate and compared their microbial compositions. What they found confirmed Moore’s suspicion. There were marked differences in the bacteria found in the stool in those that were able to eat messmate and those that were not.

How FMT can expand the koala palette

The next step for the researchers was to see whether they could put this information to use and possibly alter the gut microbes of those pickier koalas so that they could survive despite the lack of their preferred trees.

The team collected 12 wild Koalas, which they kept in temporary captivity. Meanwhile they collected stool from other wild Koalas with different dietary patterns, ones that ate a eucalypts tree called messmate. They packaged the stool into capsules and gave them to the captive, manna gum eating koalas.

They then monitored the koalas over an 18-day period and found that not only were their microbiomes altered but they were subsequently able to eat messmate - the eucalypts they had previously been unwilling to eat.

Other applications for FMT in threatened species

Though the idea of inoculating wild koalas with the fecal matter of their fellow species members may seem odd or even cruel, it is not all that extraordinary of an idea. In fact koala mothers are known to feed their children with a goopy, green poop. Yes this sounds gross, but it is necessary for the koalas to pass on their microbes to the next generation.

Given the potential of these FMTs to expand the diet of and save koalas, it is hard not to imagine the applications FMT might have in other species at risk of extinction.