Check Up: A link between taste and infections

Just in time for cold and flu season, here's some news from the weird coincidence department:

People who are good at tasting certain bitter flavors, such as those in brussels sprouts and broccoli, are better at fighting off sinus infections.

The finding comes from a team of Philadelphia researchers who say it may lead to better treatments for those with chronic sinusitis.

The key to the study was a type of detective molecule called a receptor, which performs different functions depending on its location. On the tongue, the receptor, T2R38, latches onto certain bitter-tasting compounds. That is how we taste them.

In the nose and airways, however, the researchers found that this receptor binds with a chemical that certain bacteria use to communicate with each other. That event triggers a two-pronged bodily attack against the microbes, said senior author Noam A. Cohen, an assistant professor at the University of Pennsylvania and a physician at the Philadelphia Veterans Affairs Medical Center.

First, the receptor molecules prompt nasal cells to produce nitric oxide, which in turn causes tiny cellular hairs called cilia to sway back and forth faster, clearing mucus from the system. In addition, the nitric oxide kills bacteria directly, Cohen and his colleagues reported in the Journal of Clinical Investigation.

These effects were shown in cells taken from 56 patients and grown in the lab.

The best antibacterial response was found in cells from "super tasters" - those who were 100 times better at tasting bitter compounds.

Humans are thought to have evolved the ability to taste bitter flavors because in most cases, plants with a bitter taste are dangerous to eat. It is unclear why the same receptor, when found in the airways, would have a different protective effect, said one of the paper's authors, geneticist Danielle Reed of the Monell Chemical Senses Center.

After the cellular studies, the scientists went back to the patients from whom the cells were taken. Among those whose receptors were not especially good at detecting the bacteria (or bitter taste), half were infected with the bug at the time.

But among those with super-sensitive receptors, the number infected was zero.

- Tom Avril