Ingredient record
Fructo-oligosaccharides (FOS)
“Fructo-oligosaccharides (FOS)” appears in the ingredient information of at least one indexed pet food. Preparation, inclusion amount and the rest of the formulation can differ between products.
How to read this entry
We classify this term as named ingredient in the functional ingredients category. The linked products supply the observation; they do not by themselves establish the ingredient’s nutritional effect.
Check the declared form and amount, and whether any claim concerns this ingredient alone or a tested complete product.
Evidence status
This is an ingredient index entry linked to product information. We have not completed an ingredient-specific research appraisal for this entry. A term’s presence in a product does not demonstrate a health outcome, nutritional adequacy or the effect of that product.
Source and review
Product ingredient sections checked 24 September 2026. The linked product records show the wording and available source context. Manufacturer formulations and labels may change; verify the current pack and the intended market.
Research on this ingredient
Dog
FOS and MOS in dogs: digestion, microbes and immune markers
One study with 1 reviewed arm or dose connection(s).
Arm fos-supplement
FOS and MOS in dogs: digestion, microbes and immune markers
Direct · dog. Four adult female dogs with ileal cannulas; 14-day periods.
Tested form: FOS supplied at 1 g per feeding, twice daily. Dose: 1 g per feeding, twice daily (Oral feeding supplement). Duration: 14-day periods. Comparator: The same kibble without these supplements.
Measured finding: FOS-containing treatments lowered faecal indoles and phenols. Combined FOS/MOS increased ileal IgA versus control; several reported effects were only trends.
Limitations: Very small, surgically instrumented population; short periods and multiple surrogate outcomes. Related papers may share experiments.
Protein level changes the response to FOS in dogs
One study with 1 reviewed arm or dose connection(s).
Arm fos-in-protein-factorial
Protein level changes the response to FOS in dogs
Direct · dog. 12 healthy adult dogs in a replicated four-treatment Latin square.
Tested form: Fructo-oligosaccharide (FOS) added to lower- and higher-protein foods; inclusion level not reported in the reviewed abstract. Dose: Not reported in the reviewed abstract (Food inclusion; amount not reported). Duration: 28-day periods with washouts. Comparator: Corresponding unsupplemented foods.
Measured finding: Higher protein and FOS each increased faecal ammonia. FOS increased apparent digestibility of several minerals; protein level modified some FOS effects, including bifidobacteria and protein digestibility.
Limitations: Faecal measurements are surrogate outcomes. Small healthy population; no disease-treatment endpoint.
Products listing or mentioning this ingredient
120 products linked through reviewed ingredient occurrences from manufacturer declarations or partial editorial summaries. Whole-label verification may remain pending. An ingredient’s presence alone does not establish a nutritional outcome.
- ROYAL CANIN® Medium Ageing 10+ ROYAL CANIN® Medium Ageing 10+ - ROYAL CANIN® Medium Ageing 10+; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- ROYAL CANIN® Norwegian Forest Cat Adult ROYAL CANIN® Norwegian Forest Cat Adult - ROYAL CANIN® Norwegian Forest Cat Adult; United Kingdom; manufacturer declaration Cat; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- ROYAL CANIN® Outdoor ROYAL CANIN® Outdoor - ROYAL CANIN® Outdoor; United Kingdom; manufacturer declaration Cat; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- ROYAL CANIN® Persian Kitten ROYAL CANIN® Persian Kitten - ROYAL CANIN® Persian Kitten; United Kingdom; manufacturer declaration Cat; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- ROYAL CANIN® Poodle Adult ROYAL CANIN® Poodle Adult - ROYAL CANIN® Poodle Adult; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- ROYAL CANIN® Pug Adult ROYAL CANIN® Pug Adult - ROYAL CANIN® Pug Adult; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- ROYAL CANIN® Sensible 33 ROYAL CANIN® Sensible 33 - ROYAL CANIN® Sensible 33; United Kingdom; manufacturer declaration Cat; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- ROYAL CANIN® Siamese Adult ROYAL CANIN® Siamese Adult - ROYAL CANIN® Siamese Adult; United Kingdom; manufacturer declaration Cat; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- ROYAL CANIN® X-Small Adult ROYAL CANIN® X-Small Adult - ROYAL CANIN® X-Small Adult; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Senior Dry Dog Food Rich in Chicken & Rice Senior Dry Dog Food Rich in Chicken & Rice - Senior Dry Dog Food Rich in Chicken & Rice; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Senior Recipe Wet Food for Older Dogs (400g) Senior Recipe Wet Food for Older Dogs (400g) - Senior Recipe Wet Food for Older Dogs (400g); United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Skin & Coat Dry Dog Food Skin & Coat Dry Dog Food - Skin & Coat Dry Dog Food; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Skipper's Ocean Puppy Grain Free Complete Food Skipper's Ocean Puppy Grain Free Complete Food - Ocean Puppy Grain Free Complete Food; UK; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Slim & Slender Dry Dog Food Slim & Slender Dry Dog Food - Slim & Slender Dry Dog Food; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Super Boost Topper Super Boost Topper - Super Boost Topper; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Superfoods Grain-Free Dry Adult Dog Food Salmon & Vegetables Superfoods Grain-Free Dry Adult Dog Food Salmon & Vegetables - Superfoods Grain-Free Dry Adult Dog Food Salmon & Vegetables; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Superfoods Grain-Free Dry Adult Dog Food Turkey & Vegetables Superfoods Grain-Free Dry Adult Dog Food Turkey & Vegetables - Superfoods Grain-Free Dry Adult Dog Food Turkey & Vegetables; United Kingdom; manufacturer declaration Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Yora Pate Apple & Parsnip Yora Pate Apple & Parsnip - Pate Apple & Parsnip UK formulation; UK; partial summary Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Yora Pate Beetroot & Swede Yora Pate Beetroot & Swede - Pate Beetroot & Swede UK formulation; UK; partial summary Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope
- Yora Pate Carrot & Potato Yora Pate Carrot & Potato - Pate Carrot & Potato UK formulation; UK; partial summary Dog; Source data captured; Label verification pending; Evidence applicability requires the stated ingredient and study review scope