Plant Lactic Acid Bacteria Fermented Material YJK-13

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Table of Contents
1. Development Story
　1-1　Isolation of lactic acid bacterium JK-13 strain and its effect on immunity
　1-2　Improving effect on stress-induced immune balance
　1-3　Plant Lactic Acid Bacteria Fermented Material YJK-13 Production path and nutritional components
2. Clinical data
　2-1　Antioxidant Effect
　2-2 Endurance improving effect
　2-3　Immunostimulatory effects
　2-4　Intestinal regulation

１．Development Story

• 1-1　Isolation of lactic acid bacterium JK-13 strain and its effect on immunity

Lactobacillus plantarum JK-13 is a unique lactic acid bacteria strain owned by Yaegaki Biotechnology. It is a plant-derived lactic acid bacteria isolated from traditional Japanese pickled vegetables. It shows a strong ability to activate human immune cells when taken even in small amounts. For example, 1 g of YJK-13 material contains 10 billion Lactobacillus plantarum JK-13 (heat-treated dead bacteria) which is equivalent to 100 g of yoghurt.

The human immune system cells can be divided into two main categories: innate immune cells, which attack everything “except themselves”, and acquired immune cells, which attack only their intended targets. In particular, it is now attracting attention that efficiently activating the innate immune cells of the intestinal tract with so-called good bacteria and functional ingredients contained in various foods also activates acquired immunity, leading to general immune system improvement throughout the body. Various lactic acid bacteria components are presented by antigen-presenting cells to naive T cells (Th0), which are known to balance the differentiation of helper T cells, and restore the balance from the allergy type (Th2-dominant type) common in humans to the cellular immunity-inducing Th1-dominant type.

It is known, both academically and experientially, that stress reduces immunity. In modern society people are restricted from moving freely, which can easily lead to a state of ‘restraint stress’ and decline of the immune system. In this experiment mice were confined in a narrow tube to induce chronic restraint stress, and Lactobacillus JK-13 role on the immune balance change was investigated. The test results showed that the Th1/Th2 balance was disrupted by chronic restraint stress, which was then improved by the intake of Lactobacillus JK-13.

• 1-3　Plant Lactic Acid Bacteria Fermented Material YJK-13 Production path and nutritional components

Plant Lactic Acid Bacteria Fermented Material YJK-13 (hereafter YJK-13) is a food ingredient made by liquid cultivation of lactic acid bacteria strain JK-13 (Lactobacillus plantarum JK-13). During production only soya is used as raw material with addition of dextrin. After cultivation stage the culture is sterilized, dried and powdered to the final product state.
Protein content of YJK-13 is more than 70%, which is similar to the nutritional content of soya beans. In recent years, this type of lacto-peptides has been attracting attention as a functional ingredient that works even in minute quantities. A unique characteristic of YJK-13 is high lactic acid Lactobacillus plantarum JK-13 bacteria content of 10 billion cells/g.

２.　Clinical data

• 2-1　Antioxidant Effect

Soya proteins are known to have antioxidant properties when they are converted into peptides by degrading enzymes. Various types of peroxides can cause damage to human body, however scanning experiments with them might be difficult due to their short life time. In order to investigate antioxidant activity of YJK-13 a relatively stable DPPH radical was used.

Trial outline
in vitro samples were adjusted to 2% with ion-exchange water, stirred well, and centrifuged (15 000 rpm, 3 min). Then, DPPH radical scavenging activity of the centrifugal supernatant was measured. Superoxide (O₂^–) – a typical example of reactive oxygen species, its scavenging capacity (SOD-like activity) was also investigated.

Trial results
Strong radical scavenging and SOD-like antioxidant activity of YJK-13 was observed.

Trial outline
YJK-13 amino acid protein composition is high (approximately 16%) in branched-chain amino acids (BCAA: valine, leucine and isoleucine) . Branched-chain amino acids, also called endurance-related amino acids, are reported to be useful for endurance improving together with antioxidant peptides. Therefore, the effect of YJK-13 on endurance was investigated in mice.

Trial results
An trend for increased swimming time in the YJK-13-treated group was shown compared to the control group. This suggests that antioxidant peptides and BCAAs contained in YJK-13 help to improve endurance.

• 2-3　Immunostimulatory effects

Trial results
Compared to soy peptides, YJK-13 showed a higher ability to induce IgA production in Peyer’s patch cells and IL-12 production in splenocytes. This confirms that YJK-13 is useful for stimulating mucosal and cellular immunity.

• 2-4　Intestinal regulation

Trial outline
To investigate the bowel regulating effects of YJK-13, healthy volunteers with a tendency to constipation were administered with YJK-13 for 8 weeks.

Trial results
YJK-13 intake significantly increased bowel movement frequency from week 7 of the study, and a trend towards better bowel movements in comparison to control group was observed in more than 50% of subjects.