Oral Fecal Microbiota Transplantation in Dogs with Tylosin-Responsive Enteropathy-A Proof-of-Concept Study

Abstract

A clinical trial was conducted to evaluate the effect of fecal microbiota transplantation (FMT) on the canine chronic enteropathy clinical activity index (CCECAI), fecal consistency, and microbiome of dogs with tylosin-responsive enteropathy (TRE). The trial consisted of four phases: (1) screening with discontinuation of tylosin for 4 weeks, (2) inclusion with re-introduction of tylosin for 3-7 days, (3) treatment with FMT/placebo for 4 weeks, and (4) post-treatment with follow-up for 4 weeks after treatment cessation. The study found that the treatment efficacy of FMT (71.4%) was slightly higher than that of placebo (50%), but this difference was not statistically significant due to underpowering. The most abundant bacterial species detected in the fecal microbiomes of dogs with TRE before FMT or placebo treatment were Blautia hansenii, Ruminococcus gnavus, Escherichia coli, Clostridium dakarense, Clostridium perfringens, Bacteroides vulgatus, and Faecalimonas umbilicata. After FMT, the microbiomes exhibited increases in Clostridium dakarense, Clostridium paraputrificum, and Butyricicoccus pullicaecorum. The microbiome alpha diversity of TRE dogs was lower when on tylosin treatment compared to healthy dogs, but it increased after treatment in both the FMT and placebo groups. Comparisons with the stool donor showed that, on average, 30.4% of donor strains were engrafted in FMT recipients, with the most common strains being several Blautia sp., Ruminococcus gnavus, unclassified Lachnoclostridium, Collinsella intestinalis, and Fournierella massiliensis.

Keywords: chronic enteropathy; dogs; fecal microbiome; fecal microbiota transplant; microbiome diversity; placebo; tylosin-responsive enteropathy.

Figure 1

(A) Study design of this prospective, double-blinded, placebo-controlled clinical trial in dogs with tylosin-responsive enteropathy (TRE) receiving oral FMT or placebo capsules; (B) a flow chart detailing the treatment and post-treatment phases.

Figure 1

(A) Study design of this prospective, double-blinded, placebo-controlled clinical trial in dogs with tylosin-responsive enteropathy (TRE) receiving oral FMT or placebo capsules; (B) a flow chart detailing the treatment and post-treatment phases.

Figure 2

Mean (SD) of CCECAI score during different visits of dogs in FMT and placebo groups. Data are expressed as the mean  ±  standard deviation.

Figure 3

Mean (SD) of fecal consistency score (FCS) in different visits of dogs in FMT and placebo groups. Data are expressed as the mean  ±  standard deviation.

Figure 4

Fecal dry matter percentage in individual dogs of both FMT (top) and placebo groups (bottom) throughout the study.

Figure 5

Linear regression analysis correlating fecal consistency scores and dry matter percentage.

Figure 6

Fecal microbiome composition (genus level) of the stool donor, healthy dogs, and dogs receiving FMT or placebo treatment. The relative abundances of bacterial genera with mean relative abundances of less than 1% are shown; all others are combined into the category “Other”. Samples are grouped by time point as follows: screening, inclusion, and endoscopy. “Post” samples are from the treatment and post-treatment visits. Plac—placebo.

Figure 7

Fecal microbiome composition (species level) of the stool donor, healthy dogs, and dogs receiving FMT or placebo treatment. The relative abundances of bacterial species with mean relative abundances of less than 1.4% are shown; all others are combined into the category “Other”. Samples are grouped by time point as follows: screening, inclusion, and endoscopy. “Post” samples are from the treatment and post-treatment visits. Plac—placebo.

Figure 8

Bacterial species that significantly increased in TRE dogs receiving FMT treatment according to differential abundance analysis with LinDA. None of the bacterial species examined significantly increased or decreased in TRE dogs receiving the placebo.

Figure 9

Microbiome alpha diversity (Shannon index) among TRE dogs in the FMT (A) and placebo (B) clinical groups at different time points compared to healthy dogs. The horizontal line inside each box plot represents the median; the top and bottom of each box represent the 75th and 25th percentiles, respectively; and the whiskers represent the 95th and 5th percentiles. Black squares represent mean values.

Figure 10

Beta diversity as assessed by the Bray–Curtis dissimilarity index, illustrating similarities and differences in community composition. (A) Comparison between all visits for the FMT group and healthy dog group. PERMANOVA p-value 0.001. (B) Comparison between all visits for the placebo group and healthy dog group. PERMANOVA p-value 0.001.

Figure 11

Engraftment of donor bacteria in TRE dogs receiving FMT treatment. We compared the presence of bacterial amplicon sequence variants (ASVs) found in the donor compared to FMT recipients before and after FMT treatment (excluding ASVs shared between donors and recipients pre-FMT). (A) Plots of donor bacterial amplicon sequence variant (ASV) engraftment rates across FMT recipients; 100% engraftment would indicate that all of the donor ASVs that could be shared were shared. (B) Taxonomic assignments of the donor ASVs that were most frequently shared with FMT recipients.