Cancer-detecting yoghurt could replace colonoscopies

A spoonful of yoghurt 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 yoghurt followed by a urine test — a cheap method that could improve the early diagnosis of colorectal cancer.

Sangeeta is developing synthetic molecules that can be introduced into the body via yoghurt, and that will interact with cancer in a way that produces telltale biomarkers. Those molecules can then be detected easily in urine.

She had previously developed nano-particles that find their way to tumours, 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 analyse urine and find the telltale markers. Now she has developed a paper-based urine test — like those used to test for pregnancy.

So far that 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. In new, as-yet-unpublished work, Sangeeta is developing a way to deliver the nanoparticles by modifying a type of bacteria found in yoghurt. The bacteria produce the nanoparticle biomarkers by interacting with a tumour.

Sangeeta hopes the approach will "transform diagnostics" and said she's in the process of forming a company to commercialise the approach. Because the test requires no specialised equipment, it will be particularly helpful in poor countries, she said, where few people are currently screened for common cancers. But it might also replace or augment colonoscopies. If detected early, 90 per cent of people with colorectal cancer survive for at least five years. But only 40 per cent of people are diagnosed early, partly because so few people are screened, according to the American Cancer Society.

Samuel Sia, a professor of biomedical engineering at Columbia University, said Sangeeta’s synthetic biomarkers are an "interesting concept" for providing easy and inexpensive cancer tests.

He added that nanoparticle injections have shown good reliability — at least in mice. But without data from clinical trials, he said, "I wouldn't say this is the solution yet."