Scientists have rewritten the DNA of bacteria and made probiotics safer

Modern probiotics could reach a new level – thanks to a breakthrough from a team at Kobe University. Japanese specialists have learned how to edit the DNA of bacteria so that it remains as close to natural mutations as possible. This means that such microorganisms are not subject to strict laws on gene modification and cause fewer concerns for consumers.

The development of mankind has always been accompanied by the improvement of strains of useful microorganisms – to produce wine, cheese, sour vegetables. But in recent years, attempts to modify microflora at the level of genes have been criticized because fragments of foreign DNA were often used. This approach has alarmed society and been restricted by legislation.

In response to these challenges, bioengineer Keiji Nishida and his colleagues proposed an innovative way forward. They created a DNA point editing technology called Target-AID. Unlike the well-known CRISPR-Cas9, the new technique does not break DNA, does not destroy cells and acts extremely precisely. This makes it possible to change individual parts of the genome without introducing foreign fragments.

The team tested their technology on two commercial species of lactobacilli – the same ones used to make yogurt and fermented foods. The changes were implemented with almost 100 percent accuracy. This proves the versatility of the method: it is suitable for different strains, which opens up wide horizons for the food and pharmaceutical industries.

One of the most impressive steps of the team is the elimination in the bacteria of the gene responsible for the production of a substance that can aggravate the course of type 2 diabetes. The result is a strain that produces almost none of this compound. Such probiotics are potentially safer for millions of people with metabolic disorders.

In addition, the development makes it possible to modify several stretches of DNA at once in the future, opening the way not only to the creation of new products, but also to a deeper understanding of the microbes themselves. This means that in the future we may be waiting for a new generation of probiotics – with real benefits for immunity, digestion, allergy control and even prevention of chronic diseases.

According to the creators, such bacteria can be used in food, supplements and medicines without additional restrictions. Of course, they must pass standard safety testing procedures before entering the market, but the barriers are much lower than those of classical GMOs.