Are some germs good for your baby?

When my kids were babies, I remember being obsessive
about ensuring everyone—including their dad—had
properly washed or sanitized their hands before handling 
my precious little bundles. Some of my friends were even
more protective.

But as my boys grew older, and began eating things like 
dirt and boogers—and attending daycare where there was
 rarely a child without a runny nose—I began to wonder if 
I needed to be so stringent. According to Dr. Dina Kulik, a
 pediatrician and emergency medicine doctor who works at
 Kindercare Paediatrics and SickKids hospital in Toronto,
babies can benefit from germs.

“Regular germs are actually good for babies,” she says.
“Children who are kept in too sterile an environment actually
 have higher risks of asthma and allergies than kids exposed
to a ‘non sterile’ environment. Exposure to bacteria and 
viruses allow our immune system to grow, so we can better 
protect ourselves from harmful organisms.”

She also points out that excessive hand washing and 
sanitizing depletes the natural healthy and good bacteria 
from your skin. “These good bacteria help keep the bad 
bacterial levels at low levels. If you kill off too much good 
bacteria, bad bacteria have a chance to overpopulate,” says
 Dr. Kulik.

But hand washing isn’t the only way that babies are
 exposed to good germs. According to a recent pediatric study,
 bacteria can also be transferred to infants via pacifiers. The
 study found that children whose parents “cleaned” their
 pacifier by sucking it were less likely to have asthma, eczema 
and sensitization at 18 months of age than children whose
 parents did not lick their child’s pacifier clean. In this case,
 the study concluded that parental sucking of their infant’s 
pacifier may reduce these effects, possibly by transferring
 microbes to their infant by saliva, enabling them to build 
immunity.

Some caution, however, is warranted. Premature
 babies and young newborns have very immature immune 
systems. They haven’t yet been exposed to many bacteria
 or viruses and are more at risk of bad infections. “For these
 populations, I would be more cautious about exposure to 
pets and sick contacts. However, over time it’s important to 
gradually expose infants to people and pets. This will help 
build their immune system,” she says.

As they get older, children will naturally be exposed to
more germs. “Young children have an average of 13 viral 
illnesses per year, so a persistent runny nose is normal in a 
young child,” says Dr. Kulik. “As a result, young children are
 surrounded by viral infections from their peers all the time.
 This is very hard to avoid.”

Over time, as their immune system recognizes these
 viruses, it can fight against them more easily. “That’s why 
adults often get fewer infections per year than a two-year-old.”

Dr. Kulik suggests keeping the following tips in mind:

• Don’t purposely expose kids to viral infections, but don’t overprotect them from viral exposures, either.
• Vaccines prevent against many serious infections. This is the best defense against significant illnesses that can cause death.
• As always, if your child is unwell, he/she should be seen by their healthcare provider.
• Ask your physician for more tips for building a strong immune system.

  Originally published in ParentsCanada magazine, August/September 2013.