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Description
Nichinichi Protesun B — Heat-Treated FK-23 Lactic Acid Bacteria, 2 x 31 sachets
Overview
A Japanese concentrated lactic-acid-bacteria powder from Nichinichi Pharmaceutical, in single-dose sachets. Each 1.0 g sachet supplies FK-23 material equivalent to 300 billion cells. The declaration is 8 items long and there is nothing in it that is not a bacterium, a saccharide or a plant fibre.
What FK-23 is, and what "heat-treated" means for you
FK-23 is a strain of Enterococcus faecalis that Nichinichi Pharmaceutical supplies heat-killed rather than live. That single fact answers most of the practical questions about this product: the cells are not alive, so nothing has to survive stomach acid, nothing needs refrigeration, and the count on the pack is stated as an equivalent number of cells rather than as live colony-forming units. It also means this is not a product that colonises the gut, and we are not going to suggest otherwise.
Nichinichi has not notified any health claim for this product with Japan's Consumer Affairs Agency — it is a plain food, not a Food with Function Claims and not a medicine. So this page describes what is in the sachet and how people use it, and stops there.
Protesun S or Protesun B? The two grades are not versions of the same strength. Per sachet, S supplies FK-23 equivalent to 4 trillion cells in 1.5 g and lists the bacteria first on its declaration; B supplies 300 billion in 1.0 g and is built on a corn-starch base, with three added fibres that S does not have. That is roughly thirteen times the bacterial material in S, for about four times the price. Neither is the 'better' one — B is a daily-fibre-and-bacteria powder, S is a concentrate. This page is the Protesun B. The other is here.
More Japanese supplements are in Vitamins & Supplements.
Key Benefits
- ✓ FK-23 equivalent to 300 billion cells per sachet — the figure is per 1.0 g sachet and this page says which
- ✓ Heat-treated, so no refrigeration and no survival question — the cells are not live and do not need to reach the gut alive
- ✓ 8-item declaration, printed in full below — no proprietary blend, no undisclosed carrier
- ✓ Single-dose sachets, 2 x 31 sachets per box — no measuring, no spillage, easy to travel with
- ✓ Three added fibres — hydrolysed guar gum, dextrin and resistant dextrin, which the S grade does not contain
- ✓ Honest about what it is: no health claim is notified for this product in Japan, and this page does not make one
Product Details
| Brand | Nichinichi Pharmaceutical Co., Ltd. |
|---|---|
| Country of origin | Japan |
| Product | Protesun B |
| Regulatory category | Food. No function claim notified. |
| Bacterial strain | FK-23 (Enterococcus faecalis), heat-treated |
| FK-23 per sachet | Equivalent to 300 billion cells |
| Format | Powder in single-dose sachets |
| Sachet weight | 1.0 g |
| Sachets | 2 x 31 sachets |
| Boxes in this listing | 2 |
| Ingredients | 8 items — see Full Ingredients |
| Approx. cost per sachet | ¥161 |
| Animal-derived ingredients | None declared |
Who Is This For?
- People who already know they want FK-23 specifically, and want to see the count stated per sachet rather than per box.
- Anyone who prefers a heat-treated bacterial powder to a live-culture product — no cold chain, no shelf-life anxiety, and it travels.
- People who want a supplement with a declaration short enough to read in full.
- Think twice if: you are looking for something to treat a digestive or immune condition. No claim of that kind is notified for this product, and a diagnosed condition is a matter for a doctor. And if it is the concentration you are after, the S grade carries roughly thirteen times more per sachet.
How to Use
- Open one sachet.
- Tip the powder straight into the mouth and follow with water, or stir it into water, milk, yoghurt or a cold drink.
- Do not stir it into anything hot — the material is heat-treated already, but there is no reason to cook it further, and cold or room temperature is how it is normally taken in Japan.
- Take it at whatever time of day you will actually remember. Nichinichi does not specify one, and with this category regularity is what matters.
Frequency: One sachet a day is the usual pattern. Nichinichi does not print a fixed daily amount for this line.
Full Ingredients
Full declaration as published by Nichinichi Pharmaceutical, in descending order of weight. Eight items.
Corn starch (made in Japan), maltose, lactic acid bacteria (heat-treated), hydrolysed guar gum, dextrin, oligosaccharide, resistant dextrin, cellulose.
Read the order: corn starch and maltose come before the bacteria, so this grade is a starch-based powder carrying FK-23 rather than a concentrate. Three of the eight items — hydrolysed guar gum, dextrin and resistant dextrin — are fibres that the S grade does not contain, which is a reason some people prefer this one rather than a compromise.
Nutrition per sachet: energy 3.8 kcal, protein 0.052 g, fat 0.004 g, carbohydrate 0.88 g, salt equivalent 0.00038 g, potassium 2.7 mg.
No allergen from Japan's 28-item list is declared for this product. There is no animal-derived ingredient, no gelatin and no alcohol in the declaration.
Cautions
- No health claim is notified for this product in Japan. It is a food, not a medicine, and it is not intended to diagnose, treat, cure or prevent any disease.
- Keep to the amount described on the pack. Taking more does not make it work better.
- If you are under medical treatment, taking any medicine, pregnant or breastfeeding, ask your doctor before starting.
- Introduce it gradually if you are not used to concentrated bacterial powders — some people notice a change in digestion in the first few days.
- Stop taking it and seek advice if you feel unwell.
- Not a substitute for a varied diet. Japanese labelling on this category asks that meals be balanced around a staple, a main and a side dish.
- Keep out of reach of children.
- Store away from direct sunlight, high temperature and humidity.
- Use an opened sachet at once; do not keep part of one for later.
Package Contents
2 boxes of single-dose sachets, 2 x 31 sachets in total, 1.0 g each. Nothing else is included — no scoop, no shaker.
Shipping & Store Notes
- Ships directly from Japan
- Processing time: 2–6 business days
- Tracking number provided after dispatch
- Import duties and taxes may apply depending on destination country
- Opened supplements cannot be returned for hygiene and safety reasons
Authenticity Guarantee
Every product at Tsujimoto Market is sourced directly from Japan and verified for authenticity. We never sell fakes or grey-market goods. Each order is carefully packed in Kobe, Japan and dispatched with full tracking.
FAQ
Is Protesun a medicine?
No. Our previous description called it 'the drug' and 'the preparation'. It is a food. Nichinichi has not notified any health claim for it with Japan's Consumer Affairs Agency, which means no efficacy statement of any kind is permitted for it — including ours.
Are the bacteria alive?
No, and that is by design. FK-23 is supplied heat-killed. The number on the pack is stated as an equivalent cell count, not as live colony-forming units. Practically: no refrigeration, no question about surviving stomach acid, and no colonisation of the gut.
Does it detoxify the body or lighten age spots?
No. Our earlier description said both, along with 'reduces allergic reaction manifestations' and a claim that heat-treated FK-23 is 'three times more effective for immunity boost than live bacteria'. None of those had a source and all have been removed.
How is Protesun B different from Protesun S?
By concentration and by base. Per sachet this product gives 300 billion; Protesun S gives 4 trillion in a 1.5 g sachet. The declarations differ too: on S the bacteria are the first ingredient, on B the first two are corn starch and maltose, and B adds three fibres. Japanese labelling lists ingredients by descending weight, so the order is itself the specification.
When should I take it?
Nichinichi does not specify a time, so take it when you will remember. It can go straight into the mouth followed by water, or be stirred into a cold drink or yoghurt. Avoid stirring it into anything hot.
