Evaluation of GNU100 on fecal characteristics, microbiota, and bile acid concentrations of healthy adult dogs treated with antibiotics

In recent dog and cat experiments, a novel milk oligosaccharide mimic (GNU100) positively modulated fecal microbiota and metabolite profiles, suggesting benefits to gastrointestinal health. The objective of this study was to investigate the effects of GNU100 on the fecal characteristics, microbiota, and bile acid (BA) concentrations of healthy adult dogs treated with antibiotics. Twelve healthy female dogs (n=12) were used in an 8-week crossover design study. All dogs were fed a control diet twice daily during a 2-week baseline, then randomly allotted to 1 of 2 treatments (diet only or diet + 1% GNU100 top-dressed) for another 6 weeks. From week 2-4, dogs were orally administered metronidazole (20 mg/kg BW) with meals. Fecal scores were recorded daily and fresh fecal samples were collected at week 2, 4, 5, 6, and 8 for measurement of pH, dry matter, microbiota populations, and BA, immunoglobulin A, and calprotectin concentrations. On week 0, 4, and 8, blood samples were collected for serum chemistry and hematology analysis. All data were analyzed as repeated measures using the Mixed Models procedures of SAS version 9.4. Significance was determined as P<0.05 for all measures analyzed. Metronidazole increased (P<0.0001) fecal scores (looser stools) and dramatically modified (P<0.05) fecal microbiota and BA profiles. Using qPCR, metronidazole reduced fecal Blautia, Fusobacterium, Turicibacter, Clostridium hiranonis, and Faecalibacterium abundances, increased fecal Streptococcus and Escherichia coli abundances, and increased dysbiosis index (DI). DNA sequencing analysis demonstrated that metronidazole reduced alpha diversity metrics and influenced the relative abundance of >20 bacterial genera. Metronidazole also increased primary BA and reduced secondary BA concentrations. Most antibiotic-induced changes returned to baseline by week 8. Fecal scores were more stable (P=0.01) in GNU100-supplemented dogs than controls following metronidazole administration. GNU100 also influenced fecal microbiota and BA profiles, reducing (P<0.05) the influence of metronidazole on the Chao1 alpha diversity estimate and returning fecal Fusobacterium abundance and secondary BA concentrations to baseline levels at a quicker (P<0.01) rate than controls. In contrast, GNU100 slowed (P<0.05) the return rate of fecal Turicibacter and Streptococcus abundances and DI following metronidazole administration. Metronidazole and GNU100 had minor effects on serum chemistry and hematology. In conclusion, our results suggest that GNU100 consumption may provide benefits to dogs treated with antibiotics, providing more stability of fecal scores, maintaining microbial diversity, and allowing for quicker recovery of microbiota and BA profiles.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Animal Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2022

Author dc:creator

• Belchik, Sara Elizabeth

Contributors dc:contributor

• Swanson, Kelly S
• Cattai de Godoy, Maria R
• Fahey, Jr., George C

• canine microbiome
• canine nutrition
• gastrointestinal health

Statement dc:rights

• Copyright 2022 Sara E. Belchik

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/116217

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F116217