The thought of transplanting someone else’s poop into the colon can seem nasty, and it’s understandable. Stools are a stinking mixture of water, undigested food, dead and living bacteria, and other cells and substances. However, live bacteria in the feces have been shown to be useful in the treatment of diseases and ailments of the digestive tract. That’s why doctors have been transferring excrement from healthy donors to sick patients for years, usually by colonoscopy, enema, or pill, to restore gut health.
The concept is relatively simple: good bacteria from given feces will colonize the patient’s gut if the recipient’s microbiome is unbalanced and will outgrow any bacteria that cause problems. For example, healthy fecal bacteria can be used to treat an infection with Clostridioides difficult bacteria, which can infect the human colon and cause mild to life-threatening diarrhea. In clinical trials, fecal microbiota transplants are estimated to be more than 90 percent effective in eliminating C. diff. And last month, researchers from Norway wrote in the journal Gastroenterology that patients with irritable bowel syndrome (IBS) suffer less swelling, stomach cramps, and constipation after being treated with a fecal transplant, even three years after receiving it.
David Ong, a gastroenterologist at Mount Elizabeth Hospital in Singapore, sees even greater potential for these treatments as intestinal microbes interact with our brain and other organs. Ong, who in 2014 was the first doctor in Singapore to perform a fecal transplant on a patient infected with C. diff, says recent studies suggest that the intervention could also help people with inflammatory bowel disease or obesity, or people with autism spectrum with bowel. problems related to demanding food. There are currently more than 100 clinical trials investigating the effect of fecal transplants in conditions ranging from depression to epilepsy and Covid-19 to cancer.
“Genes are what you’re born with, and that’s what it is,” Ong says. “But the gut microbiome is something you can manipulate. And if you can manipulate it to get a good result in terms of disease, that’s great.”
However, only the small question of finding the right poop remains. In addition to working as a gastroenterologist, Ong co-founded the startup Amili, which has collected more than 1,000 stool samples for transplants over the past three years. However, most volunteer donors are excluded after completing questionnaires and testing their stools, blood and saliva in the laboratory.
Lifestyle, diet, medical history, including the use of antibiotics, which can kill intestinal bacteria, and how someone was born can rule people out. (Newborns born through the vagina collect their first intestinal bacteria from their mother as they move through the vaginal canal and show greater microbial diversity than those delivered by cesarean section.) In the Norwegian trial, samples of feces were used to treat 87 patients with IBS comes from a donor: a 36-year-old man who was born vaginally; breastfeeding; he was a non-smoker; he had been treated with antibiotics only a few times; exercise regularly; and consumes large amounts of protein, fiber, minerals and vitamins. Generally, once a donor is considered healthy enough, lab technicians will examine their stool sample. Technicians are looking for diverse microbiomes, and in particular bacteria known to compete with harmful bacteria.