- Lactic acid bacteria, green onion and ginger in kimchi serve as natural antiviral agents, highly effective in preventing influenza.

- Kimchi has the greatest antiviral effect when it is the most delicious (best fermentation periods).

- When the SARS epidemic swept China, some argued that kimchi had safeguarded Koreans against the epidemic.

- A joint research team from the Korea Food Research Institute and the World Institute of Kimchi proved kimchi's effectiveness against flu for the first time in the world.

SEOUL, South Korea, July 26, 2018 /PRNewswire/ -- Kimchi, a well-known traditional fermented Korean food, is highly effective in preventing influenza virus in winter, according to the results of cell·animal experiments.

A joint research team from the Korea Food Research Institute and the World Institute of Kimchi recently announced that lactic acid bacteria and fermentation metabolites in kimchi inhibit the growth of influenza virus -- proving kimchi's effectiveness against flu for the first time in the world, along with the genetic information of strains(metagenome), fermentation metabolites, and bioactive mechanism.

Flu viruses are pathogens that cause acute respiratory conditions in winter. Swine flu (influenza A), which struck the world in 2009, and avian influenza (AI), which recently infected poultry in some countries, are two strains of influenza viruses. Due to mutation of virus, the prevention of flu from these kinds of viruses is so difficult, and infections caused by them are difficult to treat as well.

The research team, which consists of Dr. Kim, In-Ho (Korea Food Research Institute), Dr. Choi, Hak-Jong (World Institute of Kimchi), Korea University College of Medicine, and Dr. Ryu, Byung Hee (Daesang Corp., one of the leading food producers in Korea), collected kimchi samples at each fermentation stage (less-fermented, well-fermented, and over-fermented) and injected them into flu virus-infected cells and animals.

In this study, extracts from the kimchi sample at the 'well-fermented' stage (about 3-7 days after kimchi is made, when kimchi tastes best) were administered to cells infected with the influenza virus (H1N1) and the avian influenza virus (H7N9). In all of the cells, plaque formation significantly reduced, which means that the growth of the flu virus had been inhibited.

In the animal experiment where flu virus-infected mice were fed kimchi extracts, the rate of suffering from weight loss due to the flu also declined. In addition, the survival rate of the mice who consumed kimchi extracts was 30% higher than those who did not.

Dr. Kim, In-Ho of Korea Food Research Institute said, "Lactobacillus plantarum, which is produced in large quantities during the fermentation of kimchi, and its sub-ingredients such as green onion and ginger are thought to hinder the growth of influenza virus. We concluded that bioactive compounds from lactic acid bacteria produced by kimchi fermentation serve as antiviral agents by affecting the virus membrane surface or promptly activating immune cells mobilization." He added, "Our study is the world's first that scientifically verified kimchi's effectiveness against influenza viruses such as swine flu and AI viruses. In addition, we succeeded in isolating useful and safe lactic acid bacteria from kimchi, contributing to broadening its industrial applications. In other words, this can be applied not only to fermented foods including kimchi, paste, and liquors but also to animal feeds, and food and drug materials. It can also lay the milestone for the development of fermented foods and strains optimized for the constitution of Koreans, through analysis of microbial genome and metabolites in fermented foods as well as mechanism. As such, we have launched new food products in partnership with Daesang corp, aiming to contribute to safeguarding Koreans against virus threats of modern society and to strengthening Korea's competitiveness as the birthplace of kimchi."

In 2003, SARS (Severe Acute Respiratory Syndrome) was pandemic in many parts of the world including Hong Kong and mainland China, except for Korea where very few people were infected with the virus. Regarding this, some argued that kimchi has an antiviral effect. The results of the study (Effects of heat-killed Lactobacillus plantarum against influenza viruses in mice) were published in the February 2018 issue of the Journal of Microbiology.

SOURCE World Institute of Kimchi