Can gut health fight COVID? UConn researchers examine the link

Photo of Jordan Fenster
At left, undated handout image provided by the National Institute of Allergy and Infectious Diseases (NIAID) shows a clump of Staphylococcus epidermidis bacteria (green) in the extracellular matrix, which connects cells and tissue, taken with a scanning electron microscope, showing. At right, undated handout image provided by the Agriculture Department showing the bacterium, Enterococcus faecalis, which lives in the human gut, is just one type of microbe that will be studied as part of NIH's Human Microbiome Project. They live on your skin, up your nose, in your gut _ enough bacteria, fungi and other microbes that collected together could weigh, amazingly, a few pounds. Now scientists have mapped just which critters normally live in or on us and where, calculating that healthy people can share their bodies with more than 10,000 species of microbes. (AP Photo/NIAID, Agriculture Department)

At left, undated handout image provided by the National Institute of Allergy and Infectious Diseases (NIAID) shows a clump of Staphylococcus epidermidis bacteria (green) in the extracellular matrix, which connects cells and tissue, taken with a scanning electron microscope, showing. At right, undated handout image provided by the Agriculture Department showing the bacterium, Enterococcus faecalis, which lives in the human gut, is just one type of microbe that will be studied as part of NIH's Human Microbiome Project. They live on your skin, up your nose, in your gut _ enough bacteria, fungi and other microbes that collected together could weigh, amazingly, a few pounds. Now scientists have mapped just which critters normally live in or on us and where, calculating that healthy people can share their bodies with more than 10,000 species of microbes. (AP Photo/NIAID, Agriculture Department)

AP

A group of University of Connecticut researchers is tackling the question of whether the human gut microbiome is impacted by the COVID-19 vaccine and whether it might help a person’s body fight the disease.

Among the countless COVID studies underway, these researchers believe their study is the only one looking at how the virus and the vaccine interact with the gut microbiome.

“Not everybody is getting the same kind of COVID vaccine responses,” said Wanli Xu, an assistant professor at the UConn School of Nursing. “We want to understand the factors, why some people are getting better responses versus other people not. We're trying to see whether there is a component from the microbiome playing a role in these differences.”

When someone refers to a “gut microbiome,” it usually means all the microbes — microorganisms like bacteria and viruses — in the intestines.

Those microorganisms play a role in digestion, but there is a growing body of evidence that gut health is an important factor in overall wellness.

“The interaction between the gut and the lung is not a new concept,” UConn researcher Yanjiao Zhou said. “For example, when you have a flu or a cold, a lot of people also have a gut-related symptom, especially in children.”

COVID, too, can cause gut-related symptoms.

“So we suspect that maybe there is a kind of a similar mechanism that is involved with COVID, the gut and the lung interaction,” she said.

‘Pandemic stress’

Xiaomei Cong, associate dean for research at UConn School of Nursing, explained it in relation to stress.

When babies “experience a lot of stress in early life, their gut microbiome changes,” she said.

Cong explained that stress experienced in the brain and nerves is expressed through hormones that influence your gut.

“When you really feel stressful, this system really influences your microbiome,” she said.

But, Cong said it’s “bi-directional.” When your gut microbiome changes, it can affect your emotional and psychological health.

“For COVID, this disease is not only the virus, it's also the pandemic stress,” Cong said.

Cong, Xu and Zhou are essentially studying the bi-directional nature of the gut microbiome as it relates to immunity.

“So when the participant gets their vaccination, how it influences their gut,” she said.

Gut health development

Babies, Cong said, are born with no gut microbiome to speak of.

She and Xu have been studying the development of the gut microbiome in early life for the better part of a decade. Their particular study group has been the youngest babies, specifically those in the neonatal intensive care unit.

Their work has been to monitor the development of the gut microbiome in the first few weeks of life, but also what gut health might mean for that child’s growth.

“We try to look at what factors influence their development,” Cong said.

For example, their research showed that a mother’s own milk will produce a healthier baby and better gut health, as opposed to either formula or a surrogate.

As researchers in UConn’s School of Nursing, their goal has been practical.

“We can provide the evidence to show the conditions or provide the intervention,” Cong said.

The same is true now that the team has turned to COVID research. The goal, ultimately, is practical therapies that can be applied by patients to improve their own immune response. But they are not there yet.

“At this stage, it’s more like a mechanism study,” Xu said. “We want to figure out whether there is a factor, or whether there is effect.”

Those factors can be very specific, like the encouragement of a particular group of gut bacteria or the suppression of another.

“If we identify one of the bacteria, or certain type of bacteria, like a gut microbiome community, that's actually making people have weaker immune responses, that could lead to a second study, whether adding some something like probiotics or giving some kind of antibiotics to delete some certain bacterial strain, would that help with the immune responses,” Xu said. “But at this stage we don't know.”

Vaccine rates

This work, Xu, Cong and Zhou believe, is the only research of its kind being done in the United States, but they have a problem: They’re having a hard time finding people to be study participants.

The study requires patients who have not yet been vaccinated against COVID, and vaccination rates in Connecticut are high enough to make that a difficult proposition.

Every study that involves human participants must be approved by an institutional review board.

“They have to review all your protocols and make sure everything is done correctly, you're not harming people, you're not violating privacy,” Xu said. “We have to go through all the procedures before we are approved and we can really start to recruit.”

By the time they had approval, much of the state had already been vaccinated.

“We were able to get a surge of people signing up at the beginning, but then it kind of started to slow down because people already got their vaccination so that made them ineligible,” Xu said.

The team is still actively looking for participants. If you or anyone else you know might want to get involved, call 860-486-6930 or send an email to XuLab@uconn.edu.