The gut microbiota is comprised of all the bacteria, commensal, and pathogenic, residing in the gastrointestinal tract (GIT). The gut microbiota plays an important role in nutrient and mineral absorption, synthesis of enzymes, vitamins and amino acids, and production of short-chain fatty acids (SCFAs).
Now, scientists at Washington University School of Medicine in St. Louis, have discovered that GIT play a role in the severity of infection by chikungunya virus (CHIKV).
Using mice model, they discovered that faulty gut microbiomes does not generate stronge immune responses to control infection by the mosquito-borne virus.
In contrast, either recolonizing the animals’ intestines with a single Clostridium species, or giving the animals a secondary bile acid produced by the bacterium, improved immune responses, lowered levels of the virus in the mice’s blood, and even reduced the chances that a mosquito that fed on blood from infected mice would acquire the virus.
The study suggests that people with a healthy microbiome are least likely to suffer from severe complications after getting infected with chikungunya virus.
“In many viral diseases, only a subset of the people who get infected become symptomatic, and we don’t really understand why,” said Michael S. Diamond, MD, PhD, the Herbert S. Gasser professor of medicine.
“There might be things that happen during your lifetime that shape your immune system and influence whether you can stop the infection early and have minimal symptoms, or fail to stop it and develop severe disease. We found that when mice don’t have a healthy gut microbiome, not only do they get sicker, but mosquitoes that sample their blood are more likely to get infected. Promoting a healthy microbiome could be important not just for individuals who might get infected but for the whole community in breaking or reducing the cycle of transmission.”
Gut bacteria metabolize and chemically modify the dietary compounds that pass through the digestive tract, generating vitamins and other compounds as byproducts, which are absorbed by the gut cells or taken up by other microbes, and help to regulate inflammation and the body’s response to infection.
Growing evidence suggests that the intestinal microbiome can impact on antiviral immune responses not just in the gut, but at other sites in the body. The authors cite previous studies, which have shown that germ-free and antibiotic-treated mice exhibit “defects” in their innate and adaptive immune responses following infections with viruses including influenza and hepatitis B virus.
According to CDC, Chikungunya virus is spread to people by the bite of an infected mosquito. The most common symptoms of infection are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash.
There is no vaccine to prevent or medicine to treat chikungunya virus infection.
The most effective way to prevent infection from chikungunya virus is to prevent mosquito bites. Mosquitoes bite during the day and night. CDC advises people to use use insect repellent, wear long-sleeved shirts and pants, treat clothing and gear, and take steps to control mosquitoes indoors and outdoors.