Can dogs eat Natto (fermented soybeans)?
Natto (fermented soybeans)（納豆）
Safe to feed
Soybean protein and fiber, plus vitamin K2 created by fermentation.
184 kcal per 100 g
What kind of food is this?
Soybeans fermented with natto bacteria. Per 100g: 16.5g of protein, 9.5g of fiber, 3.3mg of iron, and 100mg of magnesium.
What sets natto apart is vitamin K2 (menaquinone-7), made by the natto bacteria. Vitamin K is essential for blood clotting, and is also needed for proteins involved in bone.
The sticky strings come from polyglutamic acid, a substance made by the natto bacteria. In people, one trial found a smaller rise in blood sugar after a meal when natto high in polyglutamic acid was eaten with rice, and in mice a study found a change in the mix of gut bacteria (both from NARO, Japan's national agriculture and food research organization). It has not been studied in dogs.
Soybeans contain substances that interfere with digestion, and the proteins that are the main soy allergens (glycinin and β-conglycinin). Studies on livestock feed show that fermentation with bacteria related to natto bacteria reduces them. However, no study has confirmed that this improves digestion or allergies in dogs.
How to serve
Do not use the sauce and mustard packets that come with natto (fermented soybeans) — the sauce contains salt and sugar, and the mustard is very pungent. If the beans are large, chop them or use hikiwari (crushed) natto. Soy is a food that can cause allergies, and it appears in reports of food allergies in dogs (18 of 297 dogs with a reported food allergen, 6%). The first time, start with a small amount and watch for a reaction; if itching, vomiting, or diarrhea appears, stop and consult your veterinarian. For dogs on blood thinners that work by blocking vitamin K, such as warfarin, talk with your veterinarian first.
When you have these care goals
Gut and stool care — An ingredient containing compounds produced by fermentation.
Nutrition
Natto (per 100 g, raw)
Japan's Standard Tables of Food Composition (8th ed.)
| Energy | 184 kcal |
|---|---|
| Protein | 16.5 g |
| Fat | 10 g |
| Carbohydrate | 12.1 g |
| Calcium | 90 mg |
| Phosphorus | 190 mg |
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| Fiber | 9.5 g |
|---|---|
| Moisture | 59.5 g |
| Sodium | 2 mg |
| Potassium | 660 mg |
| Magnesium | 100 mg |
| Iron | 3.3 mg |
| Zinc | 1.9 mg |
| Copper | 0.61 mg |
| Iodine | 0 µg |
| Selenium | 16 µg |
| Manganese | 1.39 mg |
| Vitamin A | 0 µg |
| Vitamin D | 0 µg |
| Vitamin E | 0.5 mg |
| Vitamin B1 | 0.07 mg |
| Vitamin B12 | 0 µg |
| Vitamin C | 0 mg |
| EPA | 0 mg |
| DHA | 0 mg |
| Alpha-linolenic acid | 670 mg |
In food-energetics terms
In traditional food therapy, this is classified as 'warming'—said to gently warm the body, and often chosen when the body tends to feel cold.
(Food energetics is a long-standing idea of supporting the body through everyday meals. Treat it as one extra hint alongside the nutrition numbers.)
How much for your dog?
Get daily estimates from weight and activity level.