The dirty secret of pharmacology is that most medicines don’t work all that well. Stomach acids erode them, the liver filters them out, and the bloodstream shunts them away. But bacteria have a knack for evading these roadblocks, so researchers are now looking to use the little critters to make drugs inside your body or nudge your immune system. Biotechnologists can delete toxic bacterial genes, insert genes for human proteins, and turn inert molecules into therapeutics. Then the bacteria can travel to where they’ll do the most good and manufacture medicine on site. Mind you, Dr. Bug could still go awry - cause an infection, recover a deleted gene, spew out the right drug in the wrong place. Don’t expect a prescription for a few years, but some promising research projects are well under way.
Bacterial Therapies in the Pipeline
a. Cancer Tracker
Because cancer is basically the body’s own good cells gone bad, the immune system rarely notices or attacks them.
Bacteria: Listeria monocytogenes causes deadly food poisoning, and the immune system responds in force at the first sign of the bacteria’s presence in the body. Stripping the bacteria of toxic genes and substituting ones that make molecules found in tumors may retrain the immune system to go after cancerous cells.
Status: Preliminary human trials later this year
b. Tumor Liquifier
Nearly everyone who dies of cancer had metastatic tumors that spread so extensively or to places so delicate that surgery wasn’t an option.
Bacteria: Clostridium novyi is a relative of the bacteria that causes botulism. It doesn’t grow in live tissue at the edges of tumors but thrives deep in their dead interiors (where there’s no oxygen), eventually liquefying them. When the immune system cleans up the mess, it learns to kill living cancer cells.
Status: Animal studies
c. Crohn’s Killer
Crohn’s disease is an inflammation of the gut that causes constant pain and frequent diarrhea. It’s probably an autoimmune disorder. The experimental protein drug Interleukin-10 quiets the immune system but misbehaves when injected or ingested.
Bacteria: Lactococcus lactis is the bacteria used to ferment milk to make cheese. Tweak it to make IL-10, and the bug passes through the stomach and makes medicine at the intestinal wall.
Status: Preliminary human trials
d. Chemo Maker
Chemotherapy destroys healthy cells almost as well as it does tumors. The ideal dose is too weak to harm patients but strong enough to beat up a malignancy.
Bacteria: Salmonella typhimurium flourishes in tumors. By adding a gene that converts a relatively innocuous chemical called a prodrug into a toxin, it can be used to fight cancer. The prodrug goes to every cell in the body but only wipes out the ones inside the tumor.
Status: Preliminary human trials
- Monya Baker
a. Cancer Tracker
b. Tumor Liquifier
c. Crohn’s Killer
d. Chemo Maker
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Turning Bugs Into Drugs
