Pandemic hygiene may be unhealthy: scientists
Higher risk of illness and chronic conditions feared for some people
The good news is that frequent handwashing, masks and physical distancing work. Falling daily COVID -19 case counts in Ontario and across Canada testify to that.
The bad news? Being hypervigilant about hygiene could have some serious health consequences down the road.
In a paper published in January, members of the Canadian Institute For Advanced Research's humans and microbiome program raised the possibility that the pandemic could profoundly change the human microbiome, making some people more susceptible to chronic conditions and diseases, including asthma and obesity.
“The COVID-19 pandemic has the potential to affect the human microbiome in infected and uninfected individuals, having a substantial impact on human health over the long term,” wrote the authors in the paper published in the journal Proceedings of the National Academy of Science in the U.S.
The lead author, University of British Columbia microbiologist Brett Finlay, calls the pandemic a real-time experiment in the impact of necessary public health measures on the microorganisms that contribute to people's overall health.
“It gives us an experiment that you can't normally do: If you lock people up for a year, does it have long-term consequences?” said Finlay. The paper, he said, is a call for scientists to study the issue, especially its impact on young children.
The microbiome is made up of the microbes living on and in the human body that play a role in human health and disease. Changing that with use of antibiotics or by limiting contact with microorganisms, especially in early childhood, can have health consequences.
The so-called hygiene hypothesis in medicine says that early-childhood exposure to certain microorganisms protects against allergic diseases and contributes to the development of the immune system.
Although sanitation and distancing to prevent the spread of the SARS-CoV-2 virus, which causes COVID-19, are necessary to protect human life, the paper warns that people should be ready for changes to the human microbiome as a result.
That could result in health consequences. Allergic responses, asthma, obesity and diabetes have all been linked to changes in the human microbiome in recent decades due, in part, to less exposure to microorganisms.
Finlay, who is author of the book Let Them Eat Dirt, said research has demonstrated there are consequences to living in a “hyperhygienic” society.
He said growing rates of obesity, asthma, inflammatory bowel disease and other conditions, especially in children, have been linked to exposure to fewer microbes.
Children who grow up on farms, for example, have lower rates of asthma and allergies.
Finlay has done research in British Columbia that links a significantly higher risk of asthma to antibiotic use in infancy. Use of antibiotics in infants has been reduced in B.C. over the last decades, something that has been matched by a reduction in rates of asthma.
He said the research paper published earlier this month was a call for people to be aware of the possible downstream impact of actions being taken during the pandemic.
“We know, based on history, that there are consequences.”
Physical distancing, alone, makes a difference to people's exposure to microbes, something that is especially crucial for infants, he said.
“A child born today in a COVID world, who is that kid interacting with? They are not getting the microbes they are normally exposed to. We know in early life it is really important to have diverse microbial exposure, and that is just not happening in COVID, so I think there is some significant concern about what goes on there.”
He said some of the impact of lack of contact with other people and places can be countered by eating a diet rich in fibre found in grains, fruits, nuts and vegetables, exercising, having contact with pets and getting outside as much as possible.
He said it is important that children are able to go outside and play “in the environmental microbes” instead of staying indoors.
Meanwhile, he said studying the impact could provide valuable information.
“We have really drastically changed society in the last year and we know these often result in significant changes in the microbiome. It is a wonderful experiment.
We are in a position to look at these things, so we need to use this opportunity to really examine this and learn from it.”