Covid ‘pandemic babies’ show two ‘fascinating’ biological changes, study finds

Lockdowns during the Covid pandemic caused two “fascinating” changes in babies’ bodies that may have protected them against illness and allergies, according to a study.

Researchers at University College Cork in Ireland found that children born while the world was in lockdown during Covid had an altered gut microbiome – the ecosystem of “good” and “bad” bacteria in the gut that aid in digestion, destroying harmful bacteria and helps control the immune system.

The biome was found to be most beneficial for babies.

Researchers believe this led ‘Covid babies’ to have lower-than-expected rates of allergic conditions, such as food allergies, compared to pre-pandemic babies, the scientists found.

They also required fewer antibiotics to treat illnesses.

The researchers analyzed fecal samples from 351 Irish babies born in the first three months of the pandemic, between March and May 2020, and compared them with samples from babies born before the pandemic.

Online questionnaires were used to collect information on diet, home environment, and health to account for variables.

Stool samples were collected at six, 12, and 24 months and allergy testing was performed at 12 and 24 months.

Newborns with Covid were found to have more beneficial microbes obtained from their mother after birth, which could act as a defense against allergic diseases.

If people have an altered gut microbiome, this can lead to the development of food allergies.

Babies born during the pandemic had lower allergy rates: About five percent of Covid babies had developed a food allergy by one year of age, compared to 22.8 percent of pre-Covid babies.

The researchers said the mothers had passed the beneficial microbes to their babies during pregnancy and acquired additional ones from the environment after their birth.

The study also found that babies born during lockdowns had fewer infections because they were not exposed to germs and bacteria.

This meant they needed fewer antibiotics, which kill good bacteria, leading to a better microbiome.

Babies during lockdown were also breastfed for longer, which provided additional benefits.

Of the babies with Covid, only 17 percent of babies required an antibiotic by one year of age.

Meanwhile, in the pre-pandemic cohort, 80 percent of babies had taken antibiotics by 12 months.

This was a “fascinating result,” said joint senior author Liam O’Mahony, professor of immunology at University College Cork, and “correlated with higher levels of beneficial bacteria such as bifidobacteria.”

Professor Jonathan Hourihane, consultant pediatrician at Children’s Health Ireland Temple Street and joint lead author of the study, said: “This study offers new insight into the impact of social isolation early in life on the gut microbiome.”

“In particular, the lower allergy rates among newborns during lockdown could highlight the impact of lifestyle and environmental factors, such as frequent antibiotic use, on the increase in allergic diseases.”

The researchers hope to re-examine the children when they are five years old to see if there are any long-term impacts of early changes to the gut microbiome.

The study was published in the journal Allergy.