Weight-loss results in obesity differ with clinical, microbial factors of FMT
Mixed-donor nonintensive fecal microbiota transplantation induced significant weight loss in certain people with obesity as well as more effectively increased butyrate-producing bacteria than single-donor intensive transplantation.
“Factors affecting FMT outcomes in subjects with obesity have not been identified,” Zhilu Xu, PhD, of The Chinese University of Hong Kong and the Microbiota Innovation Centre (MagIC Centre), said in the presentation at UEG Week. “Donor factors, recipient factors or frequency of FMT are likely to affect treatment outcomes. Therefore, we aim to determine the effect of intensive FMT on weight loss in obese subjects, to examine the impact of single- and multi-donor FMT on the recipients of gut microbiota and to identify bacterial taxonomic and clinical factors associated with weight loss after FMT.”
Xu and colleagues analyzed the fecal samples of 38 patients with obesity who received mixed-donor nonintensive FMT (nFMT) once a month for 4 months and nine patients with obesity who received single-donor intensive FMT (iFMT) for 5 consecutive days for 4 weeks. Fecal sample collection occurred at baseline, 1 month after first FMT, 1 month after last FMT and 2 to 3 months after last FMT; they followed participants up to week 52.
According to results, 13.2% of patients in the nFMT group achieved weight loss of at least 10%; no patients in the iFMT group achieved these results.
Further, researchers observed engraftment in all patients with no maintained differences between iFMT and nFMT. Xu said this “indicates that intensive FMT infusions did not induce weight loss or durable changes in gut microbiome, compared to nonintensive FMT.”
There was a durable increase in the number and temporal increase in the abundance of donor-derived species in iFMT compared with nFMT. However, mixed-donor nFMT increased the abundance and diversity of butyrate-producing bacteria, which was consistent at 1 month and 2 to 3 months after last FMT.
Overall, weight loss associated with high initial amounts and reduction after FMT of Bacteroides dorei, whereas weight loss of 10% or more associated with significantly increased amounts of butyrate-producing bacteria, including Anaerostipes hadrus, Collinsella tanakaei and Roseburia hominis.
“Although this was technically a comparison between two independent FMT regimens, all the study participants were recruited at our center at around the same time period and had comparable baseline characteristics,” Xu said. “The fecal samples were processed together with the same protocol, and the fecal material for FMT were derived from the same pool of lean donors. Therefore, we believe that these findings will be of value in the design of personalized microbial-based therapies for obesity, based on donor and recipient selection.”