A small study found that a lean person’s intestinal bacteria may successfully transfer to the obese and change their gut microbiota.
More and more research is showing that the trillions of microbes living in our digestive systems play an important role in our health, including the possible prevention of obesity. And a new study adds support to that theory, finding that obese people may be able to change their gut bacteria by receiving a fecal transplant from a lean person.
Jessica Allegretti, MD, the director of the Fecal Microbiota Transplant Program at Brigham and Women’s Hospital in Boston, and her colleagues followed 22 patients with obesity who were otherwise healthy. Participants were an average age of 40, primarily white, and predominantly female (only two men were included).
In one sitting at the start of the trial, half the subjects took 30 capsules containing freeze-dried fecal material from a lean donor. At weeks four and eight, these individuals received a maintenance dose of 12 capsules. The other half of the study group received an identical dosing of placebo (dummy) capsules.
After three months, researchers observed that the sequence of gut bacteria DNA in transplant recipients was much more similar to that of the lean donors compared with those receiving placebo. The treatment group also exhibited a decrease in primary bile acids, which are thought to be pathogenic (causing disease), according to Dr. Allegretti.
The results demonstrated that FMT was safe and well-tolerated, and the transfer of gut microbiota could be maintained.
“There really are no good, effective medical therapies for obesity right now,” Allegretti told Everyday Health. “We wanted to look at people who really struggled with weight loss their entire lives and see if we could understand the microbiome changes in these patients and what augmenting it or correcting it could do.”
The pilot investigation will be presented at Digestive Disease Week 2019 on Monday, May 20, 2019.
No Changes Were Found in an Appetite-Suppressing Hormone
Although the therapy shows promise, the study authors note that they did not see any expected changes in the intestinal hormone glucagon-like peptide 1 (GLP-1), which has been shown to suppress appetite.
“We know that this reflex is diminished in patients with obesity,” says Allegretti. “We know from studies that this mechanism gets corrected after weight loss surgery. Instead of doing surgery on the bowel, we thought that by overrunning the digestive system with these bacteria through fecal transplant, perhaps we could mimic what we see in weight loss surgery.”
The study authors plan to explore whether there were issues with their investigative measures or if different dosing might produce different GLP-1 outcomes.
Dosing for this research was based on standard amounts of FMT material given to treat Clostridium difficile infection, or C. diff, for short. The infection can cause colitis or inflammation of the colon. Currently, C. diff is the only condition for which FMT can be used. Although the U.S. Food and Drug Administration (FDA) has not officially approved fecal microbiota transplant for any indication, the FDA upholds an “enforcement discretion” policy that allows doctors to use FMT for C. diff infections when standard therapies fail.
What Is a Fecal Microbiota Transplant?
Traditionally, fecal transplant, or bacteriotherapy, has been performed by delivering donor stool to the colon through colonoscopy. Although the procedure may be getting a lot of attention in modern medicine, the idea dates to ancient China, according to research published in February 2017 in the journal Gut Microbes. Some people, however, may have qualms about receiving a fecal transplant by swallowing multivitamin-size tablets.
“Intestinal microbiota transplant can be a preferred term because they’re not really transplanting feces into these people,” says Colleen Kelly, MD, a gastroenterologist at the Lifespan Women’s Medicine Collaborative in Providence, Rhode Island, and an assistant professor of medicine at the Alpert Medical School of Brown University, who was not involved with the research. “This is a highly refined product. Yes, it did come from human stool, but it is filtered and rinsed in saline. It looks like a powder and has no odor. The capsules really contain pure bacteria. These capsules are much more appealing to patients rather than whole stool, which has kind of an ‘ick’ factor.”
Not a Magic Pill for Weight Loss
Investigators stress that this investigation is very preliminary, and the outcomes do not suggest that this microbial therapy is a cure-all for obesity. The research did not show that patients lost weight or achieved glucose peptide changes.
“I think that patients are super desperate and they are looking for answers,” says Dr. Kelly. “But we have to be mindful not to overpromise, especially in early stages like this. I don’t think any kind of microbiome therapy alone is going to be something that you give someone and the problem goes away. This is preliminary work that people will build on and maybe identify certain bacterial strains that are more common in obese people and less common in lean people.”
As fecal transplant gains more attention, Kelly warns people not to try any do-it-yourself approaches or believe everything they learn on the internet.
“There’s a YouTube video where a guy shows how to make a fecal transplant at home and he uses his friend’s stool,” she says. “He shows how to mix it up in a blender and administer it yourself. It’s not the safest thing to be doing.”
While FMT is not currently approved to boost good gut bacteria, eating certain types of dietary fiber may produce similar results. ”I tell people to up their fiber to build a better microbiome and get better bacteria,” says Kelly. “A lot of people lose weight just by doing that. You can develop good bacteria on your own without a more dramatic transplant method.”
Researchers hope to expand future research to a bigger population and explore different dosages of fecal matter.
“We hope that this data will be the first step of many toward understanding the microbial contribution to obesity and lead to better, more targeted therapies that actually do help patients lose weight,” says Allegretti.