CLAIM:
Letting children play in dirt and natural outdoor environments helps strengthen their immune system, while raising them in overly sterile conditions may increase the risk of allergies, asthma, and frequent infections later in life.
FACT:
Research shows that early exposure to everyday environmental microbes, through outdoor play, pets, and natural surroundings, helps train children’s immune systems and may lower the risk of allergies and asthma later in life. However, experts stress that this does not mean unsafe exposure to harmful germs or pollution, and basic hygiene and protective measures remain essential.
In a reel posted by Dr Manan Vora, an orthopaedic surgeon with over 6.06 lakh followers on Instagram, the doctor warns parents against raising children in overly sterile environments. In the reel, Dr Vora explains that many parents feel the urge to constantly protect their children from dirt, bacteria, and germs, but this may actually do more harm than good.
“You know, I see a lot of parents, and they have this urge to keep their babies away from any kind of dirt, infection or bacteria, but as a doctor parent, I feel this is one of the worst things you can do to your kid,” he says.
According to him, constantly maintaining an ultra-clean environment prevents the immune system from learning how to respond to everyday microbes. “Always keeping an ultra-sterile environment for your kid means their immune system is not getting exposed to any bacteria or pathogen, because of which their body never trains to fight them,” he explains.
Dr Vora further adds that such overprotection cannot last forever. “You cannot prevent the exposure forever. They will eventually go to school and play with other kids. And at that time, if their body is not trained, it can result in allergies, asthma and skin infections,” he says.
While stressing the importance of hygiene, he also encourages outdoor play. “So while hygiene habits are important, you should also let your kids play outside in the dirt so their bodies are trained to recognise and fight infections,” he adds.
The reel has gained significant attention on social media, clocking over 1.67 lakh views, 3,590 likes, and 4,441 shares.
Is getting ‘dirty’ actually good for kids’ immune systems? What research shows
Multiple scientific studies suggest that early exposure to everyday environmental microbes may play a protective role in shaping children’s immune systems.
Research from 2014 conducted on young children living in urban environments found that infants exposed to common household microbes, including pet dander, dust, and certain allergens, before the age of one had a lower risk of developing allergies and recurrent wheezing later in childhood.
Activities such as outdoor play and mud play may contribute to this natural exposure. While mud itself is not a medical intervention, it represents contact with soil-based microbes that children would otherwise miss in highly sanitised indoor settings.
Similar protective trends were observed in rural settings. A small 2016 study reported that children raised on non-industrial farms were significantly less likely to develop asthma compared to those who were not.
The biological explanation behind these findings is detailed in a 2018 scientific review. It explains the immunological mechanisms behind why reduced early-life microbial exposure is linked to increased allergic diseases (including asthma), highlighting the importance of microbial stimuli for proper immune development.
Further evidence comes from a large 2019 study that directly tested the hygiene hypothesis in children with atopic dermatitis (eczema). The study analysed 426 children diagnosed with the condition and compared them with 426 non-atopic controls. The researchers reported, “The odds ratio of atopic dermatitis first occurrence was 0.35 for children who had experienced four or more infections compared with those with no infections.”
For your daily dose of medical news and updates, visit: HEALTH
The study also found that family and environmental exposure mattered. Children with two or more siblings showed a 40 per cent lower risk of developing atopic dermatitis, while daily contact with dogs was associated with a significantly reduced risk. Summarising their findings, the authors concluded, “Early-life environmental exposures, including pathogens and commensals, act as ‘microbes contact carriers’ influencing immune system balance early in life.”
More recent evidence strengthens this link. A comprehensive 2022 review focusing on the “environmental microbiome”, the collection of microbes present in soil, air, plants, and built environments, found that early interaction with diverse microbes is largely protective against allergic diseases and asthma.
“During the critical window between birth and one year of life, interactions between our early immune system and the environmental microbiome have two consequences: our individual microbiome is populated by environmental microbes, and our immune system is trained regarding which antigens to tolerate,” the authors explained.
The review further noted that greater microbial diversity in early life dramatically reduces the risk of developing allergic diseases, although it cautioned that microbial exposure later in life may have different effects depending on individual health conditions.
Researchers have also studied how early environmental exposure affects gut health. A study titled ‘Infant gut microbiota and the hygiene hypothesis of allergic disease: impact of household pets and siblings on microbiota composition and diversity’ examined 24 healthy infants from the Canadian Healthy Infant Longitudinal Development (CHILD) cohort. Faecal samples collected at four months of age showed that infants living with pets had higher microbial richness and diversity in their gut microbiota.
“This study provides new evidence that exposure to pets and siblings may influence the early development of the gut microbiota, with potential implications for allergic disease,” the researchers concluded.
Indian researchers have echoed similar concerns. A review from the Indian Journal of Medical Research also discusses how the gut microbiome (community of microbes) plays a key role in children’s health and immune system development. It highlights that alterations in the microbiome are associated with immune-related conditions, including asthma and atopy (allergic diseases) in children.
What experts say
Dr Amit Gupta, Senior Neonatologist and Paediatrician at Motherhood Hospitals, Noida, explained that the concept is linked to the long-discussed “Hygiene Hypothesis”, which suggests that limited early exposure to microbes may weaken immune development in children.
“If a child is kept all the time indoors and not exposed to the outside environment, the immune system does not get properly trained,” Dr Gupta said. “When children start going to daycare or begin outdoor activities after the first year, they are naturally exposed to viruses and harmless microbes. These early infections help the body develop immunity.”
He added that early exposure helps the immune system differentiate between harmful and harmless substances. “Studies have shown that children who grow up around pets, farms, or natural environments tend to have a lower risk of allergies compared to those raised in overly sanitised settings,” he noted.
According to Dr Gupta, playing outdoors, touching soil, and interacting with nature can support immune regulation and may reduce the risk of allergies and asthma later in life. “Exposure to harmless environmental microbes, from mud, plants, or pets, plays an important role in strengthening the immune system,” he said.
However, he cautioned parents against confusing healthy exposure with unsafe practices. “This does not mean dangerous germs or pollutants are safe. Basic hygiene remains essential. Children should wash their hands after outdoor play, avoid extremely dirty environments, and use masks in high pollution areas when required.”
“Balanced exposure- this is the key to building a strong immune system,” Dr Gupta added.
This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS.
