Fecal microbiota transplantation in children does not significantly alter body mass index

Background: Fecal microbiota transplantation (FMT) is nowadays a promising therapy for Clostridium difficile infection (CDI) and a potential treatment for ulcerative colitis. However, it is still unclear whether the changes in intestinal microbiome will affect energy homeostasis or metabolism. This brings an intriguing question whether FMT from healthy donors affects recipient's body mass index (BMI). Methods: In our randomized placebo-controlled study children patients with CDI or ulcerative colitis were randomly divided into control and FMT groups. The change of post-FMT BMI percentile at 1, 3, 6, 12 months was calculated. The age range of CDI cohort was 1 to 17 years, while the range was 8 to 21 years for ulcerative colitis cohort. Results: We found that the BMI percentile was insignificantly changed by -0.7%, -1.8%, 1.3%, 4.6% in CDI, while by 3.6%, -3.3%, 3.7%, 7.1% in ulcerative colitis at 1, 3, 6, 12 months after FMT ("-" means decrease). Conclusions: We concluded that FMT from healthy donors does not significantly alter BMI in children with CDI and ulcerative colitis over 12 months.