If you’ve visited a supermarket recently, you might have noticed that yogurts and kombucha are taking up more shelf space. These products are two popular examples of probiotics: living bacteria touted to provide human health benefits. It’s not just a millennial fad – the probiotics market is projected to be over $60 billion by 2023. The accepted belief is that good bacteria drive out bad bacteria. Few of the probiotic promises, however, have been conclusively proven.

Researchers hypothesized that bacteria in the human gut might affect the likelihood of getting infected by Staphylococcus aureus (Staph) bacteria. This particular strain of Staph often naturally exists in areas of the body, such as the nose and gut, without causing ill effects. They collected stool samples from 200 people and analyzed the bacterial composition. People colonized with genus of Bacillus, a group of soil bacteria commonly used in probiotics, had no resident Staph in their gut or nose. Researchers found Bacillus bacteria produce chemicals called fengycins, which imitate the signal that Staph uses to communicate with each other. Fengycins prevent the disease-causing Staph from talking to one another. Driven ‘deaf’ by probiotics, the Staph could not coordinate to colonize and infect the human gut.

This study demonstrates a new way in which probiotics provide health benefits, in addition to stimulating the immune system and outcompeting bad bacteria for nutrients. During a time when bacteria, especially Staph, are becoming resistant to antibiotics, a simple surgery carries much higher risk than it used to. Probiotics could become an alternative approach to prevent bacterial infections, although more stringent regulations are needed for quality assurance.

Managing Correspondent: Veerasak (Jeep) Srisuknimit

Press Article: Probiotic bacillus eliminates staphylococcus bacteria. ScienceDaily.

Original Paper: Pathogen elimination by probiotic Bacillusvia signalling interference. Nature.

Related SITN article: Living Foods: the microbiology of food and drink. 

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