A study conducted by Hisao Okabe and colleagues at the Fukushima Regional Center for the Japan Environment and Children’s Study in Japan has revealed that exposure to pet cats or indoor dogs during fetal development or early infancy appears to correlate with a lower occurrence of food allergies among children. The research, published on March 29, 2023, in the open-access journal PLOS ONE, involved the analysis of data from more than 65,000 infants in Japan.
The study considered pets to be dogs, cats, turtles, fish, birds and hamsters and also whether each of the pets were kept indoors or outdoors.
Across some high-income countries, more than 10% of children are diagnosed with food allergies, and the incidence of food allergies in children continues to rise. Previous research has suggested a potential link between dog or farm animal exposure in pregnancy and early childhood and the reduction of food allergies.
Foods that account for 90% of allergic reactions in children are cow’s milk protein, eggs, peanut, soy, tree nuts, fish, and wheat. The exact reasons for the increasing prevalence of food allergies in American children are not fully understood. Researchers believe that a combination of genetic factors, environmental influences, changes in diet, and early-life exposures may contribute to the development of food allergies.
Some good micro organisms
Previous studies have showed that some gut micro organisms(microbiota) were present in the people who had pets in their homes showing that pets can affect an infant’s gut health either directly or indirectly through changes in the parent’s gut health.
Without getting overly technical, there were 3 main items that families with pets have which non pet owners do not. Further research is needed to know how these conditions are being created from the proximity of pets in homes.
- The first is the abundance of two bacteria, Ruminococcus and Oscillospira which are generally associated with reduced allergic responses in general. Basically who have these bacteria in their guts generally have reduced allergic reactions(food in this case).
- Increased endotoxin levels at home, which may protect against allergen sensitization by enhancing type 1 immunity and food sensitivies
- The third is the skin barrier-mediated mechanism. Atopic dermatitis is a major risk factor for the incidence of food allergies because of the disruption of the skin barrier function and increased susceptibility to food sensitivies.
The researchers considered all the different pets as part of the study but turtles, fish and birds didn’t affect the results of their analysis so they are not reported as crucial to the study.
In this study, 66,215 children were studied with their medical history and any allergies reported voluntarily into the study. About 22 percent were exposed to pets during the fetal period (most commonly indoor dogs and cats). Among children exposed to indoor dogs and cats, there was a significantly reduced incidence of food allergies, though there was no significant difference for children in households with outdoor dogs.
Children exposed to indoor dogs were significantly less likely to experience egg, milk, and nut allergies specifically.
Children exposed to cats were significantly less likely to have egg, wheat, and soybean allergies.
Perhaps surprisingly, children exposed to hamsters (0.9 percent of the total group studied) had significantly greater incidence of nut allergies.