Why do kids living with dogs suffer less from allergies and asthma? Tiny microbes
Studies suggest that infants who grow up with dogs in their home are less likely to develop asthma. Researchers may now have found one reason why. Pets, dogs in particular, may protect infants from the effects of a common virus, respiratory syncytial virus (RSV).
Infants with severe RSV infections have an increased likelihood of developing childhood asthma.
The researchers think that exposure to certain microbes in early infancy changes the early composition of an infant's intestinal flora and this sets the tone for how the developing immune system will respond later in childhood.
The researchers fed mice house dust from homes with dogs. They then exposed these mice to RSV and found that the mice did not show symptoms of infection -- airway inflammation and increased mucus production. They also compared the intestinal bacteria of dust-fed mice to mice that hadn't been fed dust and found differences in the types of bacteria living in the GI tract. These differences were seen whether or not the non-dust fed mice had been exposed to RSV.