The strain of lactic acid bacteria is Lactococcus lactis Strain Plasma, first discovered by Kirin Holdings in 2010 for its property in activating plasma cytoid dendritic cells (pDCs), also known as the command center of the immune system responsible for the defense against viral infections.
This joint research will be a randomised, double-blind, placebo-controlled, parallel-group study to investigate if Lactococcus lactis Strain Plasma can alleviate symptoms in COVID-19 positive patients with mild symptoms or are asymptomatic.
The COVID-19 pandemic occurred in December 2019, and has caused more than 300 million infections and five million deaths worldwide to date.
“COVID-19 infections are still a global social issue. There is a continued need for a method that combines efficacy against SARS-CoV-2, of which many mutant strains have emerged, and that can be administered easily to patients who do not require hospitalisation to alleviate or suppress the onset of symptoms. Recently, the Omicron variant has been identified – making the issue all that more important,” said Tatsuya Takada, assistant manager at Kirin’s corporate communications.
Kirin has conducted various clinical and non-clinical research on Lactococcus lactis Strain Plasma against influenza virus, rotavirus, and dengue virus, revealing that it has a high viral infection protection function compared to other lactic acid bacteria.
“Based on Kirin's accumulated research results on Lactococcus lactis Strain Plasma, we believe that Lactococcus lactis Strain Plasma may be effective in preventing the onset of COVID-19 and alleviating the symptoms of patients,” Takada added.
The study, which will be led by Dr Kazuko Yamamoto, a lecturer in the Department of Respiratory Medicine at Nagasaki University Hospital, will feature 100 COVID-19 positive patients between 20 to 65 showing mild clinical symptoms will be recruited across several hospitals in Japan.
Participants will be divided equally into two groups (n=50 each), one group will be given tablets containing Lactococcus lactis Strain Plasma (400 billion units/day), and the other group will receive placebo tablets. They will be taking the tablets for 14 days. Both forms of tablets will be provided by Kirin Holdings.
The primary outcome will be changes in subjective symptoms characteristic of COVID-19 infection including cough, breathing difficulty, fatigue, headache, difficulty in taste and smell, loss of appetite and chest pain, which will be evaluated by a Severity Score (4-point scale of no effect, little effect, moderate effect, and severe effect) and VAS (Visual Analog Scale).
Secondary outcomes will measure the amount and change in the SARS-CoV-2 viral load, ratio of plasmacytoid dendritic cells (pDCs), change in activation markers (HLA-DR, CD86), amount or rate of change of SARS-CoV-2 specific antibody (IgM, IgG), cytokines (IL-6, MCP-1), interferon and interferon-inducible antiviral factor in peripheral blood mononuclear cells (PBMC), and hospitalisation rate.
The study is expected to complete in April 2023.
According to Takada, the partnership with Nagasaki University came about when Kirin presented the effects of Lactococcus lactis Strain Plasma at the 95th Annual Meeting of the Japanese Association for Infectious Diseases in May 2021.
“Our company met with Dr Yamamoto there and discussed the possibility that Lactococcus lactis strain Plasma could be effective in treating asymptomatic and mildly symptomatic patients with COVID-19 infections, for these no therapeutic drugs had been developed, and it was decided to conduct research on finding new possibilities for Lactococcus lactis Strain Plasma.
“Nagasaki University and Kirin Holdings hope that Lactococcus lactis Strain Plasma could possibly become one of the new prevention and treatment methods against COVID-19.”