The Misconception of Gut Health: Why “Dead Bacteria” is the Real Treasure

How traditional Japanese Koji seasonings support your body without needing to stay alive.

“Gut Health.”

“I have to consume live bacteria!” Are you frantically choosing nothing but natto or yogurt?

“Bacteria that reaches your gut alive” — we see this phrase everywhere in commercials and on social media. But this might be a slight misconception.

Also, when it comes to Shio-koji (fermented rice koji marinade) and Koji Amazake (a sweet, non-alcoholic fermented rice drink), many people think, “It’s the koji mold itself that is good for the body, right?”

This, too, is actually a bit of a misunderstanding.

So this time, I want to share the secret of why homemade fermented seasonings and raw amazake are perfect for gut health!

*Please note: I am saying “it doesn’t have to be live bacteria,” but I am not denying the benefits of gut health using “live bacteria.”

Understand Gut Health in 1 Minute! The 4 Big Keywords

The technical terms can be a bit confusing because they sound similar, but for now, this is all you need to remember!

1. Probiotics The “live good bacteria” themselves that energize your gut. (e.g., yogurt, natto)

2. Prebiotics The “food” that nourishes and grows the good bacteria. (e.g., dietary fiber, oligosaccharides)

3. Synbiotics Consuming the bacteria (1) and the food (2) together as a set.

4. Postbiotics The “dead bacteria” and “beneficial components” left behind by the bacteria. (e.g., components of bacteria that have finished their life cycle)

“But in the end, isn’t live bacteria the best?” I feel like I can hear you asking this… but this is where the big misunderstanding lies.

The Role of “Koji Mold” — Common Knowledge for Those Who Handle Koji, but Surprisingly Unknown

“I finally got some good Shio-koji, so it would be a waste if the bacteria die when I heat it up!” There is absolutely no need to rush or worry like that. There is zero need for concern.

Actually, by the time Shio-koji or Amazake is finished, the koji mold inside has already completed its role, and most of it has already died.

In the case of fermented seasonings, it is due to the strong salt content and the lack of oxygen… In the case of amazake, it is due to the gentle warmth of low-temperature fermentation…

The koji mold leaves behind just a tiny fraction for the next generation (like spores) and dissolves itself (lysis), finishing its life cycle.

In other words, whether you consume it raw or cook with it, the idea that “koji mold will come back to life and move energetically inside your gut” is something that cannot happen from the very start.

“Then, is there no meaning in eating it ‘raw’ or making it at home…?” I feel like I hear that voice again, but it is actually quite the opposite!

Even if the koji mold is not alive when it is finished, it leaves behind a “treasure” instead.

Homemade, handcrafted fermented seasonings are already in the state of the ultimate “Postbiotics” (the legacy of the bacteria) from the very beginning, and they hold an even greater value.

Truly Amazing! The “Two Treasures” Left Behind in Fermented Seasonings and Raw Amazake

Compared to store-bought, heat-pasteurized seasonings or supplements, what makes homemade fermented seasonings and raw amazake so wonderful are the “two treasures” left behind by the koji mold.

• The “Enzymes” They Left Behind with Their Whole Lives The koji mold itself has journeyed on, but the “enzymes” (like protease) they left behind keep their active power unless they are exposed to high heat or pasteurization. Many commercial products are heat-pasteurized for long-term storage, which stops the work of the enzymes. Because it is homemade and “raw,” the active enzymes tenderize meat, bring out the rich umami of ingredients, and gently support your stomach and intestines with digestion.
• The “Legacy of the Bacteria” That Gently Reaches Your Gut = “Postbiotics” The body of the koji mold itself, having finished its role, is the very gut-health component attracting the most attention right now. “Postbiotics” = The legacy of the bacteria (dead bacteria components). You don’t need to worry about whether they die in your stomach acid. They become the best feast for the good bacteria already living in your gut, supporting your health from the inside out.

Furthermore… it is also packed with oligosaccharides (Prebiotics), which serve as food for the good bacteria! This means that with just one serving of either fermented seasoning or amazake, you are charging your body with both the food for the bacteria and the legacy of the bacteria!

[Now Fermenting] Homemade Fermented Seasonings at Cozy Cafe & Bar beyond

Savoring the “Richness of Time” — A Mature Approach to Brewed Gut Health

Some people might say it is more efficient to quickly wash down bacteria with supplements… and I have no intention of denying that choice.

But the koji mold takes about 336 hours (about 2 weeks) to slowly brew the rice, and in exchange for its own life, it leaves behind an abundance of enzymes and rich umami. I believe there is a warmth in these homemade fermented seasonings that efficiency-first methods can never replicate.

Let’s let go of that mysterious pressure of “Is the bacteria alive right now?” Why not deliciously enjoy the gentle treasures left behind by the koji mold, at your daily dining table or here at Cozy Cafe & Bar beyond?