Oxygen-Tolerant Strain of Gut Bacteria Could Advance Probiotics

Researchers from the University of Gothenburg and probiotic company BioGaia AB have announced a significant discovery that could pave the way for the development of next-generation probiotics, with potential applications for glucose control in individuals with prediabetes.

The challenge of oxygen sensitivity

The human gut hosts trillions of bacteria, known as gut microbiota, essential for digestion and immune system function. Changes in this bacterial composition have been associated with various diseases. Probiotics, or live bacteria products, have been considered promising as a treatment for these conditions. Researchers think that some probiotics could help rebalance bacterial populations and produce benefits in the body. Many of these bacteria are anaerobic, meaning they only thrive in oxygen-free conditions, like those found deep in our gut. In air, these sensitive populations quickly deplete. Now, researchers have devised a technique to make these bacteria oxygen-tolerant, helping them survive longer outside the gut. 

Natural symbiosis overcomes sensitivity

In a paper published in Nature, the researchers detail how they have tackled the oxygen sensitivity of a gut bacterium, Faecalibacterium prausnitzii. This bacterium is thought to be able to suppress the immune system and is notably reduced in the guts of people living with conditions like type 2 diabetes and cardiovascular disease.

The team achieved this by co-isolating F. prausnitzii with another bacterium, Desulfovibrio piger, which positively influences its growth and function. By “training” the bacteria in a favorable electrochemical environment, the researchers managed to support and grow a more oxygen-tolerant strain.

Professor Fredrik Bäckhed, the team's leader, explained, “By combining a naturally occurring symbiosis with ‘training’ of the bacteria, we have established a new strategy for producing otherwise oxygen-sensitive bacteria as live biotherapeutic products, which could prevent diseases when these bacteria are reduced in number.”

Impact on sugar control

The co-growth of these bacteria increased both the number of bacteria and the production of a chemical called butyrate, which has an anti-inflammatory effect. The study also confirmed that the novel combination of F. prausnitzii and D. piger is safe for human consumption and can be detected in the guts of supplemented individuals. The researchers next want to explore how supplements including these bacteria may affect sugar control in people with prediabetes.

Looking to the future, Bäckhed says he has “high hopes”.

“Further studies will show if we are correct in our hypothesis that gut bacteria have the potential to improve our health.”

Reference: Khan MT, Dwibedi C, Sundh D, et al. Synergy and oxygen adaptation for development of next-generation probiotics. Nature. 2023:1-5. doi:10.1038/s41586-023-06378-w

This article is a rework of a press release issued by the University of Gothenburg. Material has been edited for length and content.