Flu could be prevented by drinking more tea and wine, a study revealed.
Both black tea and red wine contain flavonoids – a chemical known for its antioxidant and anti-inflammatory properties.
Some gut bacteria break down flavonoids to produce a chemical that boosts the immune response.
Having a stronger immune system reduces the risk of developing flu symptoms.
“For years, flavonoids have been thought to have protective properties that help regulate the immune system to fight infections,” said first author Dr Ashley Steed, from Washington University.
“Flavonoids are common in our diets, so an important implication of our study is that it’s possible flavonoids work with gut microbes to protect us from flu and other viral infections.”
Senior author, Dr Thaddeus Stappenbeck, added: “It’s not only having a diet rich in flavonoids, our results show you also need the right microbes in the intestine to use those flavonoids to control the immune response.”
The researchers analysed human guts to find which micro-organism broke down flavonoids.
Once they found the particular bacteria, they discovered it metabolised flavonoids to produce a certain chemical which triggered the immune response.
When the chemical, known as DAT, was given to mice that were infected with flu, the mice experienced far less lung damage than mice not treated with DAT, the scientists said.
Despite showing far fewer symptoms, the mice still had the flu viruses after chemical treatment.
“The infections were basically the same,” said Stappenbeck.
“The microbes and DAT didn’t prevent the flu infection itself; the mice still had the virus. But, the DAT kept the immune system from harming the lung tissue.”
That’s important, because it means the chemical targets the immune response, as opposed to the virus. Seeing as flu vaccines aren’t 100 per cent effective, it could help to reduce the symptoms of flu viruses that vaccine’s don’t target.
There are between 250,000 and 500,000 global deaths linked to flu every year, according to the World Health Organization.