In today’s germ-phobic world full of hand sanitizers and antibacterial everything, many parents are leery of exposing their kids to dirt. But not letting your kids get dirty may backfire and increase their risk of getting sick.

There are several reasons why kids who regularly play in the dirt may be happier and healthier than those who don’t.

Every human has their own unique microbiome, a community of microbes living inside and on your body. According to the Center for Ecogenetics & Environmental Health, there are 100 trillion microbes, including bacteria, fungi, protozoa, and viruses, in a microbiome.

Many microbes are beneficial bacteria that help digest food, produce vitamins, and fight bad bacteria. Over time, especially during childhood, every human develops a baseline microbiome. Just as antibiotics kill both good and bad bacteria inside the body, hand sanitizers and soap kill good and bad bacteria outside the body and alter the microbiome.

Playing in the dirt helps replenish beneficial microbes which help maintain the baseline microbiome and a healthy balance between good and bad bacteria.

Exposure to germs early in life helps build a healthy immune system. The “hygiene hypothesis” states that children who live in overly clean environments may not be exposed to enough germs for the immune system to learn to operate properly.

Playing in dirt exposes kids to plenty of microbes to rev up the immune system and help keep it functioning as it should. In a 2012 study, mice exposed to microbes early in life had more natural killer T-cells than mice raised in a germ-free environment. Germ exposure may help prevent immune-mediated diseases like inflammatory bowel disease.

Dirt contains the harmless bacteria Mycobacterium vaccae. A 2007 study found that the bacteria stimulate serotonin production in the brain. Serotonin is a neurotransmitter that controls mood and other body functions. It’s thought that low serotonin levels may contribute to anxiety and depression.

A separate study showed that mice fed Mycobacterium vaccae experienced less anxiety and performed better on maze learning tasks.

Kids love getting dirty. They’ll take a detour to stomp through mud puddles every chance they get. Thanks to unsettling world news, school demands, extracurricular activities, and family dynamics, many kids are more stressed than ever.

They are also very busy. It’s important that kids take a break now and then from their hectic schedules to decompress and enjoy being kids. Playing in the dirt is a fun activity that kids and parents can enjoy together.

Dirt play impacts all of your child’s senses.

The various temperatures and textures of dirt stimulate the sense of touch. The earthy scent of dirt stimulates the sense of smell. The color variations of dirt and the insect life within it stimulate the sense of sight. When your child is outside playing, their sense of hearing is roused by a variety of nature sounds.

Since it’s inevitable that your child will get a little dirt in their mouth, their sense of taste is stimulated too.

Don’t immediately mop up the dirt your kids track into the house.

A 2011 study compared the incidence of asthma in children living on farms and children not living on farms. The study concluded that children living on farms who were exposed to more varieties of bacteria and fungi had less incidence of asthma.

According to Johns Hopkins Medicine, babies up to 1 year old who are exposed to pet dander and household germs have less risk of developing asthma and allergies.

Dirt is teeming with cool bugs, worms, larvae, and the occasional toad and slug. Dirt is an important part of vibrant vegetable gardens and beautiful flowerbeds. When your kids play in the dirt, they explore and experience nature. They learn how plants grow and how bugs live.

This helps instill a love of nature and being outdoors that will hopefully last a lifetime. It may also leave them with a desire to grow their own food and live a “greener” life.

According to the Centers for Disease Control and Prevention, 18 percent of children ages 6 to 12 were obese in 2012, the most recent year statistics were obtained.

Most kids spend much more time inside playing video games or watching television than playing outside. Kids who are couch potatoes have a high risk of weight gain and obesity. Allowing your kids to play in the dirt helps motivate them to unplug, head outside, and move more.

So much of kids’ time is structured. It’s important for them to follow schedules, but unstructured time is also essential.

According to the American Academy of Pediatrics, child-driven play helps build the skills needed for kids to become resilient and independent. Unstructured outdoor play like playing in the dirt helps develop motor skills and encourages creativity and problem solving.

Playing in the dirt should be encouraged, but not all dirt is safe. Don’t allow your kids to play in dirt where dogs, cats, and other small animals use the bathroom or where farm animals graze.

Kids shouldn’t play in dirt that has been treated with pesticides or chemicals. Dirt that is located near a gas station or factory that makes or has made paint, pesticides, or chemicals should also be avoided.

Hand-washing is important. It helps prevent the spread of viruses, such as the common cold and flu. Hand sanitizers are great to have on hand for an emergency mess or if your child happens to touch raw meat during a grocery shopping trip.

However, you don’t have to immediately sanitize every speck of dirt your child gets on their body. Of course, you shouldn’t encourage your kids to eat dirt, but there’s no need to panic if they occasionally eat without washing their hands.

If your kids are healthy, let them make mud pies and scrounge for earthworms. Allow them the enjoyment of walking barefoot through the yard and planting seeds in the garden. They’ll make happy memories and develop a love of being outdoors. They’ll also have a better chance of maintaining a healthy microbiome and immune system.