Effects of a veterinary gastrointestinal low-fat diet on fecal characteristics, metabolites, and microbiota concentrations of adult dogs treated with metronidazole.
Study Goal
The researchers aimed to determine how a veterinary low-fat diet affected fecal characteristics, metabolites, bile acids, and microbiota in dogs recovering from antibiotic treatment.
Results Summary
The low-fat diet helped recover fecal pH, dry matter percentage, metabolite concentrations, and certain bacterial genera post-antibiotic treatment, though some bacterial taxa did not fully recover. Diet also influenced lithocholic acid levels but did not impact dysbiosis index or bacterial alpha diversity recovery.
Population
24 healthy adult dogs (7.38 ± 1.95 years; 7.67 ± 0.76 kg body weight).
Effective Dosage
Not specified for the low-fat diet (only metronidazole dosage: 20 mg/kg BW twice daily).
Duration
4 weeks (after 2 weeks of baseline and 2 weeks of antibiotic treatment).
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
metronidazole | increase | fecal scores | dogs | - | increased | #1 |
metronidazole | decrease | fecal short-chain fatty acid concentrations | dogs | - | reduced | #2 |
metronidazole | decrease | fecal branched-chain fatty acid concentrations | dogs | - | reduced | #3 |
metronidazole | decrease | fecal phenol concentrations | dogs | - | reduced | #4 |
metronidazole | decrease | fecal indole concentrations | dogs | - | reduced | #5 |
metronidazole | increase | primary BA concentrations | dogs | - | increased | #6 |
metronidazole | decrease | secondary BA concentrations | dogs | - | decreased | #7 |
metronidazole | decrease | fecal bacterial alpha diversity | dogs | - | reduced | #8 |
metronidazole | neutral | abundance of 58 bacterial genera | dogs | - | altered | #9 |
metronidazole | increase | dysbiosis index | dogs | - | increased | #10 |
diet | neutral | fecal pH | dogs | - | altered | #11 |
diet | neutral | fecal dry matter percentage | dogs | - | altered | #12 |
diet | neutral | fecal metabolite concentrations | dogs | - | altered | #13 |
diet | neutral | fecal immunoglobulin A concentrations | dogs | - | altered | #14 |
diet | neutral | change in lithocholic acid | dogs | - | affected | #15 |
diet | neutral | recovery of over 25 bacterial genera | dogs | - | impacted | #16 |
Antibiotics are known to cause loose stools, disrupt the fecal microbiota, and alter fecal bile acid (BA) profiles of dogs. Recovery may be aided by diet, but little research has been conducted. The objective of this study was to determine how a veterinary low-fat diet affected the fecal characteristics, metabolites, BA, and microbiota of dogs receiving antibiotics. Twenty-four healthy adult dogs [7.38 ± 1.95 yr; 7.67 ± 0.76 kg body weight (BW)] were used in an 8-wk completely randomized design study. During a 2-wk baseline, all dogs were fed a leading grocery brand diet (GBD). Over the next 2 wk, dogs were fed GBD and received metronidazole orally (20 mg/kg BW twice daily). At week 4, dogs were randomly allotted to one of two treatments [GBD or Blue Buffalo Natural Veterinary Diet GI Gastrointestinal Support Low-Fat (BB)] and fed for 4 wk. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter content, and metabolite and BA concentrations. Fecal microbiota populations were analyzed using 16S rRNA gene amplicon sequencing and qPCR-based dysbiosis index (DI). All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of treatment, time, and treatment*time and significance set at P < 0.05. Metronidazole increased (P < 0.0001) fecal scores (looser stools), reduced fecal short-chain fatty acid, branched-chain fatty acid, phenol, and indole concentrations, increased primary BA concentrations, and decreased secondary BA concentrations. Metronidazole also reduced fecal bacterial alpha diversity, altered the abundance of 58 bacterial genera, and increased DI. During antibiotic recovery, changes in fecal pH, dry matter percentage, and metabolite and immunoglobulin A concentrations were altered (P < 0.05) by diet. Fecal BA concentrations recovered quickly for all dogs. Change in lithocholic acid was affected (P < 0.0001) by diet, but other BA were not. Recovery of over 25 bacterial genera was impacted by diet (P < 0.05). While many bacterial taxa returned to baseline levels after 4 wk, others did not fully recover. DI and bacterial alpha diversity measures recovered quickly for all dogs but were not impacted by diet. In conclusion, metronidazole drastically altered the fecal microbiota and metabolites of dogs. While most variables returned to baseline by week 8, diet may be used to aid in recovery.