A simple taste test pioneered in Baton Rouge could help public health officials determine which segments of the population are more vulnerable to the coronavirus and who should be prioritized first for vaccination.

Over a three month period, Dr. Henry Barham, a rhinologist at Baton Rouge General and Sinus and Nasal Specialists of Louisiana, and others tested the taste receptors of nearly 2,000 participants — asking whether thin paper strips tasted bitter, sweet or like nothing at all — and later followed their outcomes if they became infected by the coronavirus. 

About a quarter of participants tested couldn't detect bitter flavors at all and were categorized as "non-tasters," while another quarter could taste exceedingly small quantities of bitter flavors and were labeled "super-tasters." The rest inhabited a middle ground and were called "tasters."

Loss of taste or smell is one of the most common symptoms among those suffering from COVID-19.

The study, currently under peer review for publication, showed that "non-tasters" were significantly more likely to be hospitalized once infected and faced an average of 23 days of symptoms.

Meanwhile, none of the participants considered "super-tasters" faced hospitalization and their symptoms lasted an average of five days. 

"The test seems to be wildly predicative of who gets the coronavirus, how severely they get it and the duration of their symptoms," said Barham, who conducted the research alongside Drs. Christian Hall and Mohamed Taha.

The test takes about a minute to perform and measures the prevalence and effectiveness of a person's taste receptors — chemical structures that act as a warning signal for the body, stimulating a noxious or painful response when confronted with a toxic or bitter substance. 

Barham said some super tasters gag or vomit when taking the test. 

The receptors also act as a defense mechanism, which may explain why super tasters experienced less severe outcomes. When activated, the receptors produce additional mucus to dilute out the pathogen. They also produce the chemical nitric oxide, which prevents viruses like the coronavirus from replicating.

Barham said that widespread testing of taste receptors could help identify people at higher risk of contracting and experiencing severe symptoms of the coronavirus as well as lay out a road map for distributing an already scarce vaccine. 

Top stories in Baton Rouge in your inbox

Twice daily we'll send you the day's biggest headlines. Sign up today.

"We have a test that's inexpensive, easily scalable, has the potential to test people on a huge scale and stratify who needs a vaccine," Barham said. 

He said the test is also useful when it comes to determining treatment options, noting that non-tasters shouldn't wait until their symptoms worsen to seek out medical attention. 

The new study ran from July to September. It followed a smaller, retroactive study that was recently published in the International Forum of Allergy and Rhinology — a peer-reviewed scientific journal. That study followed 100 people who had already tested positive for the coronanvirus. 

Of that group of 100, 21 people who were tested either while they were hospitalized with the virus or afterward could not distinguish the tastes of any of the strips. The remaining 79 who could differentiate the tests to varying degrees experienced "mild to moderate" coronavirus symptoms that did not require hospitalization. None of the 100 patients were in a category that Barham classifies as a “super taster” — someone who strongly tastes the differences in each paper strip.

A “super taster” himself, Barham sees his new test as a cheap, valuable tool that public health officials can use in addition to others to try to balance coronavirus concerns with reopening schools, businesses and other parts of the economy.

"I think it has the potential to show how we return to society," Barham said. "Is there a group that can go back to work and feel confident and safe about it?"

Even “super tasters” should still get vaccinated at some point, Barham said, because the innate immunity their taste receptors hint at could still wear off eventually, especially as they age.

For now, knowing his own status has helped to give Barham a level of comfort with coronavirus that he didn’t have early on. Ear, nose and throat specialists like himself are generally at high risk for exposure. They perform tracheostomies to help coronavirus patients breathe when they’re coming off ventilators, among other procedures that send potentially infectious respiratory droplets into the air.

Even though his research has yet to finish peer review, Barham said the public locally can call his office if they're interested in setting up an appointment to learn their own taster status.


Email Blake Paterson at bpaterson@theadvocate.com and follow him on Twitter @blakepater