Fecal Microbiota Transplantation: How important is the BMI of the stool donor?

Currently fecal microbiota transplantation (FMT) “best practices” exclude obese stool donors based on a report of germ-free mice gaining weight after FMT from mice with obesity and based on a case report of an individual with 34 pound weight gain after FMT.

A recent report (M Fischer et al. Clin Gastroenterol Hepatol 2018; 16: 1351-3) suggests that the the BMI of the stool donor does not affect recipient weight after a single FMT procedure for C difficile infection.

This analysis included 173 patients with a mean age of 57 years.  One group of 103 were from a randomized control trial; in this group, 66 (64%) received FMT from a normal weight (BMI 18-24.9) donor and 37 (36%) received FMT from an overweight (BMI 25-29.9) donor. Among an additional 70 individuals from an observational cohort, 25 received FMT from normal weight donor, 30 received FMT from overweight donor, and 15 received FMT from an obese donor.

Key finding:

  • There was no significant difference in BMI among the FMT recipients up to 48 weeks after a single FMT.  Based on data from Figure 1, patients who received FMT from normal weight donor had slightly higher mean weight gain at 48 weeks afterwards (not statistically-significant)

The authors caution that a prospective study is required to confirm these findings and in the interim, they recommend exclusion of obese/overweight FMT donors.

My take: There are plenty of willing stool donors –so who knows if this will ever be examined adequately.  This study challenges the idea that FMT from an obese donor will result in recipient obesity, presumably via changes in the microbiome.

Related blog posts:

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.