The longitudinal effect of a multi-strain probiotic on the intestinal bacterial microbiota of neonatal foals.
BACKGROUND
The microbiota plays a key role in health and disease. Probiotics are a potential way to therapeutically modify the intestinal microbiota and prevent disease.


OBJECTIVE
The aim of this study was to investigate the effects of probiotics on the bacterial microbiota of foals during and after administration.


METHODS
Randomised placebo controlled field trial.


METHODS
Thirty-eight healthy neonatal foals enrolled in a previous study were selected. The foals had received a multi-strain probiotic (four Lactobacillus spp. 3-4 × 103colony-forming units (cfu)/g each, Bifidobacterium animalis spp. lactis, 1 × 103-4cfu/g) or placebo once daily for 3 weeks. A total of 3 faecal samples were collected from each foal at 2-week intervals and assessed via metagenomic sequencing. The Wilcoxon test was used to compare data between treatment groups.


RESULTS
There were no changes on the phylum, order or class level between treatment groups at any age (all P>0.05) but some significant changes in relative abundance of families. Probiotic administration did not result in an increased relative abundance of lactobacilli or bifidobacteria at any age (Lactobacillus: P = 0.9, P = 0.1 and P = 0.2, Bifidobacterium: P = 0.3, P = 0.6 and P = 0.1 for Weeks 2, 4 and 6, respectively). Lactobacillus was enriched in the probiotic group at Week 6 on LEfSe analysis (linear discriminant analysis score 0.34, P = 0 .02). There was no effect on alpha diversity (all P>0.2) or community structure when parsimony and unifrac analysis were applied (all P>0.6).


CONCLUSIONS
There were limited effects of probiotic treatment on the bacterial microbiota of foals. The studied probiotic based on lactobacilli and bifidobacteria has a limited potential for therapeutic modification of the gastrointestinal microbiota.
Vetsuisse Faculty, Equine Department, University of Zurich, Switzerland. angelika_schoster@hotmail.com.|Faculty of Health and Medical Science, Department of Veterinary Disease Biology, University of Copenhagen, Denmark. angelika_schoster@hotmail.com.
A
A
Schoster
Faculty of Health and Medical Science, Department of Veterinary Disease Biology, University of Copenhagen, Denmark.
L
L
Guardabassi
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Canada.
H R
HR
Staempfli
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Canada.
M
M
Abrahams
Department of Pathobiology, Ontario Veterinary College, University of Guelph, Canada.
M
M
Jalali
Department of Pathobiology, Ontario Veterinary College, University of Guelph, Canada.
J S
JS
Weese
D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D000069982:Bifidobacterium animalis / Q000502:physiology*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005260:Female; D006736:Horses / Q000254:growth & development / Q000382:microbiology*; D007422:Intestines / Q000382:microbiology*; D007778:Lactobacillus / Q000502:physiology*; D008297:Male; D019936:Probiotics / Q000008:administration & dosage*
D004269:DNA, Bacterial

Bifidobacterium
; 
Lactobacillus
; gastrointestinal flora; horse; metagenomic sequencing