You’re reading a gut supplement label. Ingredient identity, amount, and evidence matter more than the category name.
What do common gut health terms mean?
Use the definitions to compare the categories, then check the evidence for the product you are considering.
| Term | Definition |
|---|---|
| Probiotic | Live microbes in amounts shown to provide a benefit |
| Prebiotic | Substrate selectively used by microbes with a health benefit |
| Postbiotic | Inactivated microbes or components with a demonstrated benefit |
| Synbiotic | Live microbes and selectively used substrates with a health benefit |
| CFU | Count of viable microbes able to form colonies |
| Microbiome | Microbes, their genes, and their surrounding environment |
| Dysbiosis | Altered microbial community composition or function |
| Strain | A distinct version within a microbial species |
| SCFA / butyrate | Compounds produced during microbial fermentation |
Probiotic
Check both the organism and the amount studied.
Prebiotic
The prebiotic consensus requires selective microbial use and a demonstrated benefit.
Inulin and FOS are examples when evidence supports the intended use.
Where supplements fit
Use the glossary to compare ingredients.
The choice of product still depends on your dog’s diet, health history, and medications.
Postbiotic
Postbiotics require a demonstrated health benefit. Fermentation byproducts alone do not automatically qualify.
Preparations differ. Compare the exact ingredient with the study and follow the product’s storage directions.
Synbiotic
The synbiotic guidance distinguishes complementary and synergistic combinations.
CFU (colony-forming unit)
- Meaning
- CFU describes colony-forming units in a live microbial preparation.
- Timing
- Check whether the count applies at manufacture or expiry.
- Limit
- The count alone does not establish benefit.
Microbiome
Diet, age, and medication can affect the gut microbial community.
Dysbiosis
Dysbiosis describes altered microbial composition or function. The metronidazole study in dogs provides one example.
Gas, stool changes, or itchy ears alone cannot establish that dysbiosis is present.
Strain
Two products with the same species on the label can contain different strains.
Think of Labs: field-line and show-line Labs are the same breed but can behave very differently.
Microbial strains work the same way.
Check whether a study used the same strain and amount as the product you are considering.
Findings about one strain may not apply to another.
SCFA / butyrate
Gut microbes produce short-chain fatty acids during fermentation.
Butyrate is one example and is used by cells lining the colon.
A fiber’s role depends on which microbes use it and what they produce.
Look for evidence about the specific ingredient and intended use.
Putting it to work at the store
- Read the strain names, and check the strain code if the label lists one.
- Check when the CFU count applies, and follow storage directions.
- Compare the product with evidence for the concern you want to discuss.
Further nutrition guidance
Use this guide alongside the WSAVA Global Nutrition Guidelines.
Common questions
What's the difference between a probiotic and a prebiotic?
A probiotic supplies live microorganisms with a demonstrated benefit.
A prebiotic is a substrate selectively used by microbes with a demonstrated benefit.
What does CFU mean on a dog supplement label?
CFU measures viable microbes that can form colonies.
Check the serving size, the date to which the count applies, and the storage directions.
Why does the strain code matter?
A strain code helps you check whether the product matches the organism used in the research.
Ask the brand if it is unclear.
Can this tell me which product to buy?
No, it'll help you read a label, but the right choice depends on your dog's history, diet, and any medications.
