The results from the first randomized clinical trial on fecal transplants for obesity are in, paving the way for a potential future treatment that involves gut bacteria changes. The pilot study involved 22 obese participants who were otherwise healthy, half of whom received fecal transplants from slim donors. Researchers found gut bacteria changes in the recipients, but the effects on weight loss are murky.
The study took place over the course of 12 weeks, involving 11 patients who took capsules filled with fecal matter from donors, and another 11 who received placebo capsules. The research focused specifically on the potential effects the transplant may have on obesity.
The team behind the study looked at a gut hormone called glucagon-like peptide 1 (GLP1) in the study’s participants; this hormone is linked to the feeling of satiation that happens after someone has eaten. Someone who is unable to feel properly satiated after eating may overeat, leading to weight gain and potentially obesity.
The results were mixed, with the researchers finding that the fecal transplant caused changes in recipients’ gut bacteria, as well as changes in stool samples and a drop in a select bile acid. However, the study’s participants did not experience weight loss nor any changes to the GLP1 hormone.
Past studies have found that similar transplants could make obese mice slimmer and vice versa; additional research in humans is needed to better understand the results. Talking about the study was lead author Jessica Allegretti, MD, who said:
In our clinic, we see patients who really don’t have any other medical problems, but just cannot lose weight. It is a very important patient population that we really wanted to give focus to and try to help understand … Our study adds an encouraging first step in trying to understand the role the gut microbiome is playing in metabolically healthy people with obesity.