Researchers found that a Lactococcus lactis strain of plasma could result in an early recovery of smell and taste dysfunction in COVID-19 patients and a reduction of the viral load. The postbiotic was researched and developed by Kirin Holdings.

L. lactis strain plasma is a lactic acid bacteria that activates plasmacytoid dendritic cells (pDC), which play a crucial role in the immune system. 

The clinical trial determined that L. lactis strain plasma helped maintain the pDC blood levels decreased in COVID-19 patients, which were significantly reduced in the placebo group. 

“Kirin Holdings hopes that L. lactis strain plasma will become one of the new treatments or adjunctive care to patients with mild COVID-19,” Tatsuya Takada, corporate communications manager at Kirin Holdings, tells NutritionInsight.

“Right now, with these kinds of research, we are exploring its potential as a pharmaceutical product. Although we are advancing research and development for drug development, we cannot provide details at this time. However, we will consider various possibilities.”

“Although this research and development were for pharmaceutical products, we will license L. lactis strain plasma out to domestic and overseas companies in the food field and expand ‘immune care’ to a wide range of consumers by launching more products.”

Clinical trial 
Nagasaki University in Japan conducted a double-blinded, randomized controlled trial on the efficacy and safety of the ingredient. During 14 days, one group consumed four capsules containing 400 billion L. lactis plasma in total against a placebo. 

“The efficacy against chemosensory disturbance, which has not been observed with antiviral drugs, was observed in this study,” notes Takada. 

However, the researchers found no difference in the two groups for seven key symptoms of COVID-19, which was the primary focus of the trial: cough, shortness of breath, fatigue, headaches, anosmia and dysgeusia (losing sense of smell and taste), anorexia and chest pain.

“The number of subjects was small, 50 in each group and there was no observed difference in the primary endpoint,” comments Takada.

He continues that the questionnaire used was only partially appropriate for the Omicron strain, based on clinical symptoms for the Delta variant of COVID-19.

Previous research
According to Kirin Holdings, previous studies showed that L. lactis strain plasma stimulated pDC as a first-line defense against viral infectious diseases. Clinical studies indicated that the product enabled pDC and can suppress the onset of an illness from influenza virus, rotavirus and dengue. 

based on the scientific evidence, Kirin Holdings’ IMuse with L. lactis strain plasma was the first branded ingredient to achieve the “Foods with functional claims for immune health” label on its products in Japan.

“We will continue researching L. lactis strain plasma to confirm its effectiveness in treating various infectious diseases,” adds Takada. 

The company will also continue its immune care awareness activities through PR and by developing “immune care” classes at elementary schools, concludes Takada. 

“In Japan, to ensure that society as a whole realizes the importance of ‘immune care,’ we will promote ‘immune care’ awareness-raising activities not only by ourselves but also by involving outside companies, organizations, government agencies and local governments.”