Peer-reviewed publication · Companion animals · In the living system
After an abrupt diet change in twelve dogs, faecal microbes and metabolites shifted within days, then levelled off.
- No humic or fulvic material tested
In twelve laboratory dogs switched abruptly to a very different diet, faecal fermentation products and microbes changed within days and were described as settled by the last sample, while stools loosened.
Lin et al., 1 August 2022. Animal Microbiome 4:46.
Scope, material and route
- Studied
- Adult female Beagles, mean age 5.16 years, mean body weight 13.37 kg
- Design
- Crossover trial; each 28-day period had 14 days on the baseline diet, then 14 days after an abrupt change. Period order and randomisation are not described
- What changed
- Baseline: a dry experimental kibble. High-fibre: the same kibble with soluble corn fibre (Nutriose) top-dressed. Canned: Ol' Roy Cuts in Gravy with Savory Beef
- Route
- Feed, once daily, fed to maintain body weight
- Exposure
- 22.5 g a day of soluble corn fibre; or a canned diet with 41.27 percent protein and 24.35 percent fat on a dry matter basis, against 28.30 and 14.36 percent in the kibble. Study exposure, not application guidance.
- Duration
- Two 28-day periods; 13 days of sampling after each change
Study design
The dogs
Adult female Beagles; each received both test diets, one per period.
12 dogs
Switch to kibble plus fibre
The same kibble with 22.5 g a day of soluble corn fibre.
- Acetate, propionate, total short-chain fatty acidsRose
- Faecal pHFell quickly
- Faecal scoreLooser stools
Switch to a canned diet
A commercial canned diet, higher in protein and fat.
- Protein fermentation productsRose
- ButyrateHigher than on the fibre diet
- Faecal scoreLooser stools
Each 28-day period, by day; the diet changed abruptly on day 15
Faecal samples on days 13, 16, 20, 24 and 27, marked above the bar.
- Baseline kibble days 1 to 14
- Test diet days 15 to 28
More study details
- Research question
- When do faecal microbial taxa, microbial genes and metabolites shift and stabilise after a drastic diet change in dogs?
- Experimental unit and sample size
- The individual dog; 12 dogs, each receiving both test diets; faeces sampled five times per period
- Comparator
- Each dog's own day 13 sample on the baseline diet, and the other test diet
- Outcomes measured
- Faecal score, pH and dry matter; short-chain and branched-chain fatty acids, phenols, indoles and ammonia; bacteria by 16S rRNA gene and shotgun sequencing; microbial gene (KEGG orthology) abundance
Findings
Twelve adult female Beagles ate a dry experimental diet for 14 days, then switched abruptly to the same diet with 22.5 g a day of soluble corn fibre, or to a commercial canned diet richer in protein and fat, in a crossover design. Faeces were sampled on days 13, 16, 20, 24 and 27. Fermentation products, microbial composition and microbial gene content moved quickly in opposite directions on the two diets: fibre raised acetate and propionate, the canned diet raised protein fermentation products. The authors describe most measures as stable by day 16 to 24. Stools became looser after both changes. The study had no gradual-transition group, so it does not establish a universal transition period or show that abrupt changes are advisable.
| Outcome | Comparison or result | Interpretation |
|---|---|---|
| Faecal score | Rose (looser stools) after both changes (P < 0.001) | Both abrupt changes loosened stools |
| Faecal dry matter | Fell after both changes and stayed below baseline; higher on the fibre diet than the canned diet (P < 0.001) | A change on both diets |
| Faecal pH | Fell quickly on the fibre diet and was lower than on the canned diet on days 16, 20 and 24 (P < 0.001) | A rapid response to added fibre |
| Acetate, propionate, total short-chain fatty acids | Rose on the fibre diet and were higher than on the canned diet | The expected response to fermentable fibre |
| Butyrate | Not affected by time; higher on the canned diet (P < 0.05) | Did not follow the fibre pattern |
| Protein fermentation products | Branched-chain fatty acids, phenols, indole and ammonia rose on the canned diet and were higher than on the fibre diet (P < 0.001) | A rapid response to more protein reaching the gut |
| Community composition (shotgun) | No genus differed between groups on day 13 (P > 0.05); groups then separated (P < 0.001) | Diet moved the community in opposite directions |
| Species relative abundance by day 27 | Fibre diet: 99 species higher, 59 lower. Canned diet: 22 higher, 56 lower (P < 0.01) | Larger shifts after added fibre |
| Microbial gene abundance | No shift on the first ordination axis; groups separated on the second by day 20 | Gene content, not measured activity |
| Time to stability | Most stool measures and metabolites by day 16; pH and alpha diversity by day 20; taxa by day 16 to 24 depending on method; valerate kept rising on the fibre diet | Described from the time course, not tested formally |
Days count from the start of each 28-day period; the diet changed on day 15. Most metabolite values appear only in figures, so directions and P-values are given as the text reports them. Values are extracted from the source as reported; no raw data were available.
Interpretation and limits
What this record supports
In these twelve laboratory dogs, faecal fermentation products and microbial composition responded within days of a large diet change and were described as stable by the last sample, 13 days after the change.
What remains uncertain
- Transition practice. Both changes were abrupt and there was no gradual-transition group, so the study does not establish a universal transition period and does not show that abrupt changes are advisable.
- Stools. Faecal scores rose after both abrupt changes, which argues against reading a rapid microbial settling as a reason to switch diets suddenly.
- Stability. Judged from five sampling days, the last 13 days after the change, without a formal test; drift after day 27 is unknown.
- Population. Twelve adult female Beagles in individual laboratory pens; the authors call for work in client-owned dogs in varied settings.
- Design. The canned diet differed from the baseline kibble in protein, fat, fibre, moisture and format at once. Period order and randomisation are not described.
- Reporting. Read totals (84.3 million aligned against 70.3 million mappable) and the significance threshold for species (P < 0.01 against adjusted P < 0.05) differ between the results and methods.
Which part of the framework it informs
Environmental conditions
The physical, chemical and management context.
Microbial activity
What microbial communities do within that context.
This record informs this area.Observable function
What can be observed or measured in the host or wider system.
This record informs this area.
- a Colon wall
- b Food residue and fibre
- c Bacteria
- d Mucus layer
Source, funding and review
- Source type
- Peer-reviewed publication
- Associated products
- No humic or fulvic material was tested. This record does not assess an associated product.
- Funding and relationships
- USDA Hatch Grant ILLU-538-937 and NomNomNow, Inc. Three authors (Jha, Shmalberg and Honaker) hold stock options in and/or are employed by NomNomNow; the other authors declare no conflicts of interest. The canned diet was a Walmart product and the fibre a Roquette product; the source of the dry experimental diet is not stated.
- Review status
- Prepared as an editorial summary. External scientific review has not been completed.
- What was read
- Full text read on PubMed Central (full-text XML via Europe PMC). Supplementary tables and figure values were not read.
- Original title
- Longitudinal fecal microbiome and metabolite data demonstrate rapid shifts and subsequent stabilization after an abrupt dietary change in healthy adult dogs
- Authors
- Lin CY, Jha AR, Oba PM, Yotis SM, Shmalberg J, Honaker RW, Swanson KS
- Publication
- Animal Microbiome 4:46, 1 August 2022
- DOI
- 10.1186/s42523-022-00194-9
- Summary prepared by
- Carbon Biome Project
- Date added
- 19 October 2026
- Cite this summary
- Carbon Biome Project. After an abrupt diet change in twelve dogs, faecal microbes and metabolites shifted within days, then levelled off. Evidence library record, added 19 October 2026. carbonbiomeproject.com/evidence/lin-2022-abrupt-diet-change-adult-dogs/