Associate Professor Liu Shao Quan (left) and Miss Chan Mei Zhi Alcine (right) from the Food Science and Technology Programme at NUS created a novel probiotic beer that boosts immunity and improves gut health. Photo: NUS

Two researchers from the National University of Singapore have developed a sour beer that is infused with a probiotic strain of bacteria, Lactobacillus paracasei L26.

L. paracasei is known to neutralize toxins and viruses, and help regulate the human immune system. It is already incorporated into a variety of dairy products to help improve gut-health.

Chan Mei Zhi Alcine, a student in the Food Science and Technology Program at NUS said she regularly consumes dairy-based probiotic beverages, and wanted to apply similar techniques to brewing a “gut-friendly” beer flavor.

“The health benefits of probiotics are well known. While good bacteria are often present in foods that have been fermented, there are currently no beers in the market that contain probiotics,” said Alcine in a university release.

With the help of Associate Professor Liu Shao Quan, the duo spent nine months perfecting their recipe and ensuring they had the optimal amount of live probiotics in the beer.

They isolated the L. paracasei bacterium from human intestines and grew the probiotic, as well as the yeast, in pure cultures.

The team altered some aspects of the conventional brewing and fermentation processes to successfully create the beer with the live probiotic.

The final result was a sour beer with an alcohol content of 3.5 percent. It takes about a month before it is ready to drink.

“For this beer, we used a lactic acid bacterium as a probiotic micro-organism. It will utilize sugars present in the wort to produce sour-tasting lactic acid, resulting in a beer with sharp and tart flavors,” said Alcine.

But, as she also explained, developing sufficient counts of live probiotics in beer proved to be challenging because the hop acids in beer prevent probiotics from growing and surviving.

Alcine and Shao Quan have filed for a patent to protect the sour beer recipe. The duo believes they hit a sort of sweet spot in the market – according to Shao Quan, food and beverage products containing probiotics have increased in recent years, and a similar trend has been seen with a boost in craft and specialty beer flavors. The sour beer they developed could be an attractive option for consumers in both groups.

But further researcher may be needed to test how effective the live probiotics in the beer are for gut and immune health before they can market it as a “gut-friendly” beer.