The Fermentation Process That Creates Probiotics
Natto is a traditional Japanese food made from fermented soybeans. The process involves soaking and steaming whole soybeans and then adding the beneficial bacteria, Bacillus subtilis natto. The mixture is then left to ferment under controlled temperature and humidity for a period of 24 to 36 hours. This careful process allows the bacteria to proliferate, transforming the plain soybeans into the distinctive, sticky, and highly nutritious natto. The fermentation not only creates its unique texture and flavor but also makes the nutrients in the soybeans more bioavailable and adds a potent dose of probiotics.
The Probiotic Power of Natto
Not all probiotics are created equal, and the Bacillus subtilis found in natto is particularly noteworthy. This is a spore-based probiotic, which means the bacteria are encased in a hardened shell that protects them from harsh environments. This allows a high percentage of the live bacteria to survive the acidic conditions of the stomach and reach the intestines, where they can have the most beneficial effect. In contrast, many probiotics found in other fermented products, like yogurt, can be more susceptible to destruction by stomach acid.
How Natto Strengthens Your Gut Microbiome
Once the Bacillus subtilis spores reach the large intestine, they can colonize and support a healthy gut flora. A balanced and diverse gut microbiome is crucial for numerous bodily functions, and natto's contribution is significant. It works in several ways to benefit digestive health:
- Balances Gut Bacteria: The beneficial bacteria from natto help to restore and maintain a healthy balance of microorganisms in the gut, which can be disrupted by diet, stress, or antibiotics.
- Improves Digestive Function: The fermentation process aids in breaking down the complex carbohydrates and proteins in the soybeans, making them easier to digest and absorb. This can help reduce issues like bloating and gas.
- Supports the Immune System: A large portion of the body's immune system resides in the gut. By promoting a healthy microbiome, natto helps to strengthen overall immune function, enabling the body to better fight off pathogens.
- Produces Prebiotic Effects: While a probiotic itself, the fiber content in natto acts as a prebiotic, serving as food for the beneficial bacteria in the gut. This dual action makes natto especially effective for promoting a flourishing intestinal environment.
More Than Just Probiotics: The Nutrient Profile
Natto is rightly considered a superfood due to its dense nutritional profile, which extends well beyond its probiotic content. The fermentation process increases the bioavailability of many vitamins and minerals.
Key Nutrients in Natto
- Nattokinase: A powerful enzyme produced during fermentation that has been studied for its anticoagulant properties, which may help improve blood flow and support cardiovascular health by breaking down blood clots.
- Vitamin K2 (MK-7): Natto is one of the richest plant-based sources of this vital nutrient. Vitamin K2 plays a crucial role in bone health by helping to properly distribute calcium and preventing arterial calcification, which supports a healthy heart.
- High-Quality Protein: Natto provides a complete, easily digestible plant-based protein source with a wide range of essential amino acids.
- Dietary Fiber: Its high fiber content, both soluble and insoluble, aids in digestion and helps promote regularity.
Natto vs. Other Fermented Foods
To better understand natto's unique position, it's helpful to compare it with other well-known fermented foods.
| Feature | Natto | Yogurt | Sauerkraut |
|---|---|---|---|
| Main Probiotic Strain | Bacillus subtilis natto | Lactobacillus, Streptococcus thermophilus | Lactobacillus species |
| Probiotic Survivability | High (spore-based, survives stomach acid) | Varies, can be reduced by stomach acid | Varies, influenced by preparation methods |
| Other Key Nutrients | Vitamin K2, Nattokinase | Calcium, Vitamin B12 (often fortified) | Vitamin C, Iron, Fiber |
| Fermentation Base | Soybeans | Dairy milk | Cabbage |
| Taste & Texture | Sticky, stringy, pungent, nutty | Creamy, tangy, mild or sweet | Sour, crunchy, tangy |
| Ideal Consumption | Eaten raw or with minimal heat to preserve probiotics | Ready-to-eat, can be added to recipes | Can be eaten raw or cooked, but high heat destroys probiotics |
How to Incorporate Natto into Your Diet
While natto's strong aroma and sticky texture can be challenging for some, its health benefits are worth exploring. To make it more palatable, many people enjoy it in traditional Japanese ways:
- Over Warm Rice: A classic pairing, often with a dash of soy sauce and some spicy mustard to balance the flavor.
- As a Topping: Mix it into salads, scrambled eggs, or with vegetables for a nutrient boost.
- In Soups: Add it to miso soup at the end of cooking to warm it without destroying the delicate probiotics.
- In Smoothies: For a texture-free option, blending natto into a smoothie can mask the flavor while still delivering the probiotic punch.
Conclusion
There is no doubt that natto is a powerhouse of probiotics. The Bacillus subtilis natto bacteria, with their highly durable spore form, are particularly effective at surviving and supporting the gut microbiome. Combined with its wealth of other nutrients like vitamin K2, nattokinase, and fiber, natto is truly a fermented superfood. While the unique taste and texture may require an acquired palate, its profound benefits for digestive, immune, and cardiovascular health make it an excellent addition to a healthy diet.
For those interested in the scientific properties of Bacillus subtilis, further research is available from reputable sources like the National Institutes of Health. Probiotic properties of Bacillus subtilis DG101 isolated from ...
