Probiotic yeast robots could treat IBD

Probiotic yeast robots could treat IBD
A new study published in Nature Medicine shows that genetically engineered yeast can respond to inflammation and successfully relieve inflammatory bowel disease (IBD) symptoms in mice.
IBD is an umbrella term for a number of conditions that are characterized by persistent inflammation of the gastrointestinal tract. The two most common forms of IBD are Crohn’s disease and ulcerative colitis. Inside the human gut, there are various bacteria, fungi, and other microbes that maintain a delicate balance, with a far-reaching influence on our health. Scientists have shown that certain chronic conditions, such as IBD, are linked with this so-called dysbiosis.
In this new study, the researchers argued that to treat IBD, a probiotic would need to serve many functions, including halting inflammation, reversing tissue damage, and rebalancing gut bacteria. Dr. Francisco Quintana, an investigator at the Brigham and Women’s Hospital, and colleagues wanted to design a probiotic that could address all these needs.
“What we wanted to […] do was to use a platform that would allow us to manipulate the new response in a very specific way, when and where needed,” Dr. Quintana told Medical News Today. “And that led us not to any probiotic but actually to yeast.” Affectionately termed “yeast robots” by the scientists, the probiotics are developed from Saccharomyces cerevisiae, a species of yeast that is also used to make beer and wine and in baking. It is not commonly used as a probiotic but lives naturally in the human gut as part of a healthy microbiome.
Dr. Quintana and his team used CRISPR-Cas9, a type of gene-editing technology, to introduce a gene that is activated by inflammation in the gut. When the yeast senses inflammation, it secretes an enzyme that degrades inflammatory molecules called extracellular adenosine triphosphate (eATP), thereby reducing inflammation.
The engineered yeast produces different amounts of the enzyme, depending on how much of the inflammatory signals are present. In this way, the yeast probiotic is “self-tuning” and can provide a highly localized response to specific sites of inflammation within the gut. The researchers tested the probiotics in mice with various types of IBD. After orally administering the engineered yeast, they found that the mice had lower expression of genes that promote inflammation in the colon.