Bacteria engineered to secrete rheumatoid arthritis drug in the body

Instead of injections or pills, why not engineer bacteria to secrete therapeutic molecules from within our gut? A new study is demonstrating this futuristic idea, showing how a genetically modified probiotic can produce an experimental anti-inflammatory molecule and effectively treat rheumatoid arthritis in rats.

"People don't like to have injections for the rest of their lives," said co-corresponding author Christine Beeton, from the Baylor College of Medicine. "In the current work, we explored the possibility of using the probiotic bacteria Lactobacillus reuteri as a novel oral drug delivery platform to treat rheumatoid arthritis in an animal model."

The new research focused on engineering a strain of Lactobacillus reuteri bacteria, which has previously been established to be a safe probiotic in h

umans. Plus, according to Beeton, the bacteria is not known to colonize the gut, so its effects on patients will only ever be transitory.

"Another reason we chose L. reuteri is that these bacteria do not remain in the gut permanently," added Beeton. "They are removed as the gut regularly renews its inner surface layer to which the bacteria attach. This opens the possibility for regulating treatment administration."

The researchers modified the bacteria to secrete a peptide called ShK-235, which is an analog of a peptide extracted from the Caribbean sea anemone. Over the last decade this molecule has been closely studied for its anti-inflammatory properties. In particular, it has been found to block the activation of certain immune cells implicated in diseases such as psoriasis, rheumatoid arthritis, inflammatory bowel disease and multiple sclerosis.

Image source: Josef Reischig / Wikimedia Commons.