Long COVID, long-haul COVID, post-acute COVID-19, post-acute sequelae of SARS CoV-2 infection (PASC), long-term effects of COVID, and chronic COVID- these are all names for a condition that affects certain people that have been infected with the COVID-19 virus. While most people recover without complications, some people have symptoms that can last for many, many months. Symptoms can include fatigue, cough, memory issues or "brain fog", stomach and neurologic issues.
There are many thoughts to what causes Long COVID. Long COVID is very similar to chronic fatigue, which has always been tought to be caused by a viral infection. Essentially, a virus, like COVID, enters the body, the body fights off the infection, but never fully recovers and gets back to normal. Why this happens is unclear. While the CDC notes that Long COVID occurs more often in people who had severe COVID-19 illness, anyone who has been infected with COVID-19 can experience post-COVID conditions, even people who had mild illness or no symptoms from COVID-19.
One potential factor is the gut. You intestines, which are responsible for absorbing the food we eat and eliminating waste products are involved in more than just digestion. There are trillions of microbes (bacteria, fungi, and virusesl) that live in our gut. They are collectively known as the gut microbiome. The gut microbiome plays an important role in more than just digestion. They protect our gut and bodies from other harmful infections, is involved in our overall metabolism, and plays an important role in immunity. Research has shown that changes in gut microbes may contribute to a variety of diseases and conditions, including Long COVID.
A study published in Nature showed that patient who have COVID 19 have an imbalance of of good, protective bacteria and harmful, illness causing bacteria in the gut. These more harmful bacteria, secondary to gut damage, can leave the gut and go directly into the blood stream causing dangerous secondary infections during acute COVID-19. While not definitely the sole reason behind Long COVID, secondary infectious are thought to play a role in COVID 19 illness lingering for so long. Thus a disrupted gut microbiome may play an important role in the development of Long COVID symptoms.
This is important, because one key to curing Long COVID might be fixing the disrupted gut microbiome in Long COVID patients. This can be done by using probiotics, pre-biotics and other supplements and natural agents that restore normal gut function as well as restor a more health gut microbiome.