Cancer-Detecting Yogurt Could Replace Colonoscopies

 

Engineered yogurt bacteria could make detecting colorectal cancer and other diseases as simple as a pregnancy test.

• By Kevin Bullis on October 2, 2014

Why It Matters

One in 20 people in the United States develops colorectal cancer.

The strips of paper shown here can be used to detect synthetic biomarkers tied to diseases such as colorectal cancer. The lines indicate the presence of such biomarkers in urine.

A spoonful of yogurt could soon offer a cheap and simple way to screen for colorectal cancer.

Sangeeta Bhatia, a professor at MIT, is working to replace costly and uncomfortable colonoscopies and MRIs with a helping of yogurt followed by a urine test—a cheap method that could improve the early diagnosis of colorectal cancer.

Bhatia is developing synthetic molecules that can be introduced into the body via yogurt, and will interact with cancer in a way that produces telltale biomarkers. These molecules can then be detected easily when passed in urine.

Bhatia previously developed nanoparticles that find their way to tumors, and are then broken into smaller pieces by enzymes produced by the cancer. The broken up particles are small enough to be collected and concentrated by the kidneys, after which they are excreted.

The first iteration of the technique involved the use of lab instruments to analyze urine and find the telltale markers. Now Bhatia has developed a paper-based urine test—like the one you’d use for pregnancy. So far this test has been demonstrated in mice for colorectal cancer and liver fibrosis.

The nanoparticle work, described in a paper earlier this year, requires an injection (see “A Paper Diagnostic for Cancer”). In new, as-yet-unpublished work, Bhatia is developing a way to deliver the nanoparticles by modifying a type of bacteria found in yogurt. The bacteria produces the nanoparticle biomarkers by interacting with a tumor.

Bhatia hopes the approach will “transform diagnostics,” and says she’s in the process of forming a company to commercialize the approach. Because the test requires no specialized equipment, it will be particularly helpful in poor countries, she says, where few people are currently screened for common cancers. But it might also replace or augment colonoscopies.

If detected early, 90 percent of people with colorectal cancer survive for at least five years. But only 40 percent of people are diagnosed early, partly because so few people get screened, according to the American Cancer Society.

Samuel Sia, a professor of biomedical engineering at Columbia University, says Bhatia’s synthetic biomarkers are an “interesting concept” for providing easy and inexpensive cancer tests. He adds that nanoparticle injections have shown good reliability—at least in mice. But without data from clinical trials, he says, “I wouldn’t say this is the solution yet.”