healthHealth and Medicine

Poop Transplants Give Some Patients Improved Cognitive Function


Tom Hale

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist

The precise science of this is not yet clear, but it hints at the mysterious connection between the gut, bacteria, and the brain. T. L. Furrer/Shutterstock

Fecal transplants, where doctors transfer poop from a healthy donor to another patient's gut, have been shown to be a promising treatment for a number of gastrointestinal conditions. You might think it sounds a little icky, but there’s unbelievable potential hiding in the billions of bacteria found in other people’s poop.

Now, new research suggests that fecal microbiota transplantation (FMT) could be used to help manage health conditions outside of the gut – even serious liver problems and liver-related brain diseases.


As presented at The International Liver Congress 2018 in Paris last week, scientists accidentally discovered that FMT can produce “sustained clinical and cognitive improvements” for patients with liver cirrhosis, and possibly help mitigate the decline in brain function that occurs with a severe version of the condition known as hepatic encephalopathy (HE).

The study enrolled 20 men with liver cirrhosis and recurrent HE. After receiving an FMT, patients were found to have distinctly fewer HE episodes and fewer hospitalizations over the duration of a year. In other words, the fecal transplant appeared to have helped the patients with their condition, even the debilitating brain disease of HE.

This remarkable effect could be thanks to a number of bacteria that hang out in the gut. There is some evidence to suggest that HE patients have a lower number of certain “good” gut bacteria, such as Lachnospiraceae and Ruminococcaceae, as well as high numbers of the “bad” pathogenic bacteria Enterobacteriaceae. 

“In conducting the original study, we primarily wanted to evaluate whether FMT was safe in patients with recurrent HE compared with SOC alone,” explained lead author Dr Jasmohan Bajaj from Virginia Commonwealth University and McGuire VA Medical Center in Richmond, US.


“We identified a single stool donor from a universal donor bank who had the highest relative abundance of Lachnospiraceae and Ruminococcaceae, and FMT enemas were prepared using a single stool specimen provided by this donor.”

In a more general sense, FMT work by introducing beneficial bacteria into a person’s intestinal biome, usually via a tube through the nose or inserted directly into the colon. This helps patients foster a healthier bacterial microbiome, which has been implicated in everything from our mental health and sleep to obesity and food cravings. The precise science of how this works is not yet clear, but once again, it hints at the mysterious connection between the gut, bacteria, and the brain.

“Although this was a small randomized trial, we believe it confirms that FMT from a rationally selected donor was safe and associated with substantial long-term improvements in both clinical and cognitive outcomes in patients with cirrhosis and recurrent HE,” added Dr Bajaj. “These findings now need to be confirmed in a larger patient population.”


healthHealth and Medicine
  • tag
  • liver,

  • transplant,

  • fecal transplant,

  • gut bacteria,

  • clinical,

  • biome,

  • gut flora,

  • liver cirrhosis,

  • hepatic encephalopathy