Researchers at Washington University School of Medicine in St. Louis have reported that particular gut microbe can prevent severe flu infections in mice by breaking down flavonoids commonly found in foods such as black tea, red wine, and blueberries.
The research indicates that this strategy can prevent severe damage from flu when the interaction occurs prior to infection with the influenza virus. This study also explains the wide variation in human responses to influenza infection. The study was published in the journal Science on August 2017. Influenza is characterized by fever, cough and body ache. It is a common and sometimes deadly viral infection of the upper respiratory tract. Older adults, pregnant women, young children, and people with chronic health problems such as asthma and heart disease are most prone to serious flu complications. The researchers aimed to identify role of microbes in providing protection.
“We were able to identify at least one type of bacteria that uses these dietary compounds to boost interferon, a signaling molecule that aids the immune response. This prevented influenza-related lung damage in the mice. It is this kind of damage that often causes significant complications such as pneumonia in people,” said the study’s senior author, Thaddeus S. Stappenbeck, MD, PhD, the Conan Professor of Pathology & Immunology.
The researchers screened human gut microbes looking for one that metabolized flavonoids. Stappenbeck and Steed identified one such microbe that they suspected might protect against flu damage. The microbe, called Clostridium orbiscindens, degrades flavonoids to produce a metabolite that enhances interferon signaling. “The metabolite is called desaminotyrosine, otherwise known as DAT,” Steed said. “When we gave DAT to mice and then infected them with influenza, the mice experienced far less lung damage than mice not treated with DAT.”
According to Influenza Vaccines Market report published by Coherent Market Insights, Influenza virus is transmitted primarily by respiratory secretions or droplets of the infected person. Although the lungs of DAT-treated mice didn’t have as much flu damage, their levels of viral infection were identical to those in mice that didn’t get the treatment. Researchers are working on identifying other gut microbes that also may use flavonoids to influence the immune system, as well as exploring ways to boost the levels of those bacteria in people whose intestines aren’t adequately colonized with those microbes.