Abstract:
Canine acute hemorrhagic diarrhea syndrome (AHDS) has been associated in some studies
with Clostridioides perfringens overgrowth and toxin-mediated necrosis of the intestinal
mucosa. We aimed to determine the effect of a single fecal microbiota transplantation
(FMT) on clinical scores and fecal microbiomes of 1 and 7 dogs with AHDS from New Zealand and South Africa. We hypothesized that FMT would improve AHDS clinical scores and
increase microbiota alpha-diversity and short-chain fatty acid (SCFA)-producing microbial
communities’ abundances in dogs with AHDS after FMT. We sequenced the V3-V4 region
of the 16S-rRNA gene in the feces of AHDS FMT-recipients and sham-treated control dogs,
and their healthy donors at admission, discharge, and 30 days post-discharge. There were
no significant differences in median AHDS clinical scores between FMT-recipients and
sham-treated controls at admission or discharge (P = 0.22, P = 0.41). At admission, the
Shannon diversity index (SDI) was lower in AHDS dogs than healthy donors (P = 0.002).
The SDI did not change from admission to 30 days in sham-treated dogs yet increased in
FMT-recipients from admission to discharge (P = 0.04) to levels not different than donors (P
= 0.33) but significantly higher than sham-treated controls (P = 0.002). At 30 days, the SDI
did not differ between FMT recipients, sham-treated controls, and donors (P = 0.88). Principal coordinate analysis of the Bray-Curtis index separated post-FMT and donor dogs from
pre-FMT and sham-treated dogs (P = 0.009) because of increased SCFA-producing genera’s abundances after FMT. A single co-abundance subnetwork contained many of the
same OTUs found to be differentially abundant in FMT-recipients, and the abundance of
this module was increased in FMT-recipients at discharge and 30 days, compared to shamtreated controls. We conclude in this small pilot study FMT did not have any clinical benefit.
