[Red Yeast Rice Incident Research Report] The Choice of Industrially Mutated Strains Questioned by a Millennium of Red Yeast Rice Culture — Kobayashi Pharmaceutical Did Not Distinguish Between Strains with a Thousand Years of Dietary History and Those Without —

Kunsei Club Co., Ltd. (Hayashima-cho, Tsukubo-gun, Okayama Prefecture) published a research report on the red yeast rice incident on its corporate website on June 9, 2026, titled: "The Choice of Industrially Mutated Strains Questioned by a Millennium of Red Yeast Rice Culture — Kobayashi Pharmaceutical Did Not Distinguish Between Strains with a Thousand Years of Dietary History and Those Without."

▼Target Article URL

https://kunsei.com/archives/984

June 2026

The Choice of Industrially Mutated Strains Questioned by a Millennium of Red Yeast Rice Culture — Kobayashi Pharmaceutical Did Not Distinguish Between Strains with a Thousand Years of Dietary History and Those Without—

[Abstract] The NITE BP-412 strain used in Kobayashi Pharmaceutical's "Beni-koji ColesteHelp" is believed to be an industrially bred strain created by mutagenesis of Monascus pilosus NBRC4520, based on the correspondence with a published patent (Gunze Limited, JP2009095304A) and deposit information. It is fundamentally different from traditional red yeast rice molds that humans have consumed for over a thousand years in terms of genetic origin, development purpose, and metabolite profile. Kobayashi Pharmaceutical's product design, which equated these two under the name "beni-koji" and directly applied the safety framework of traditional food, likely had a structural problem.

1. Core of the Problem: Equating Under the Name "Beni-koji"

Kobayashi Pharmaceutical treated the traditional red yeast rice mold with over a thousand years of dietary history and the NITE BP-412 strain used in product manufacturing as the same "beni-koji" and commercialized it.

However, this is akin to placing a Chihuahua and a wolf in the same category under the classification of "dog." Even if the biological classification name is the same, their genetic origin, modification history, and metabolite profiles are fundamentally different.

The analogical application of safety based on the commonality of names — this is where the structural problem in Kobayashi Pharmaceutical's product design likely lies.

2. Facts Shown by the Published Patent: BP-412 Was Artificially Created

Gunze Limited's published patent (JP2009095304A, filed October 18, 2007) explicitly states the following:

"We performed mutagenesis on Monascus pilosus NBRC4520 and attempted to screen for strains with high monacolin K productivity, leading to the acquisition of said red yeast rice strain."

The purpose of the mutagenesis is also stated in the same patent. Intentional mutation breeding was carried out due to the industrial requirement that conventional strains "cannot achieve the monacolin K content (2%) necessary for supplement raw materials."

The strain was deposited at the National Institute of Technology and Evaluation (NITE) Patent Microorganisms Depositary under accession number NITE P-412, and the correspondence with the "NITE BP-412" strain whose use was announced by Kobayashi Pharmaceutical can be confirmed from public records.

Furthermore, Kobayashi Pharmaceutical's official news release (July 17, 2018) itself announced the use of the "Monascus pilosus NITE BP-412 strain" in the manufacture of Beni-koji ColesteHelp.

3. Comparison of Traditional Red Yeast Rice Mold and BP-412 Strain

Origin/Source

Wild strain existing in nature (over 1000 years of dietary history)

Artificially bred strain created by UV or other mutagenesis of Monascus pilosus NBRC4520

Purpose

Fermentation, coloring, preservation (traditional food manufacturing)

Achieving 2% monacolin K content (industrial supplement production)

Metabolite Profile

Safety confirmed through long-term dietary experience

Unknown metabolites resulting from mutagenesis may exist

Primary Source

Historical food culture and accumulated academic knowledge

Gunze Patent JP2009095304A (filed October 18, 2007)

As shown in the table above, the two share only the name "beni-koji" and should be regarded as genetically distinct biological entities.

4. The Problem with Kobayashi Pharmaceutical's Product Design: Consequences of Equating the Two

Traditional red yeast rice molds have over a thousand years of dietary history, and their safety is supported by historically and academically accumulated knowledge. On the other hand, the BP-412 strain is an industrial strain created by mutagenesis in the 2000s and has no equivalent dietary history.

Nevertheless, Kobayashi Pharmaceutical treated both under the same category of "beni-koji" and applied the safety evaluation framework for traditional foods directly to the industrial mutant strain.

The design inherently carried the potential for formulation without adequate separation and identification of the metabolite composition resulting from mutagenesis — this is the issue that should be verified as the starting point of this incident.

As a manufacturer that has used red yeast rice as a traditional food ingredient for approximately 14 years, Kunsei Club Co., Ltd. will continue to disseminate research reports on this issue.

Supporting Documents

1. Gunze Limited Published Patent JP2009095304A (filed October 18, 2007)

Explicitly states "Acquisition of a high monacolin K-producing strain through mutagenesis of Monascus pilosus NBRC4520"

2. Gunze Limited Patent JP5283363B2 (registered June 7, 2013)

Deposited at the Patent Microorganisms Depositary under accession number NITE P-412

3. Kobayashi Pharmaceutical Co., Ltd. Official News Release (July 17, 2018)

Officially announced the use of "Monascus pilosus NITE BP-412 strain"

[Published by]

Kunsei Club Co., Ltd. Representative Director & Pharmacist Masaaki Mori

611-1 Maegata, Hayashima-cho, Tsukubo-gun, Okayama Prefecture 701-0303

TEL: 086-483-0602 E-mail: sales@kunsei.co.jp