Did you know that your body is home to trillions of bacteria? These bacteria live on many different parts of your body – from your skin to your gut to your lungs. The hygiene hypothesis suggests that the lack of early exposure to a wide-range of different microorganisms (like bacteria) increases susceptibility to allergic diseases, such as allergies, eczema, and asthma. Numerous studies have reported that household pets and siblings are crucial sources for exposure to microorganisms. However, few studies have examined how exposure to pets and siblings are associated with the variety of microorganisms found in the human gut.

Researchers in Canada recently published a paper on the association between the microorganisms found in infants’ guts (also called gut microbiota) and the presence of household pets or siblings. They collected stool samples from 24 infants and asked the infants’ mothers to complete a questionnaire reporting the number of household pets and siblings. The results? Infants living with pets tended to have a greater diversity of gut microorganisms than those without pets; infants with older siblings had decreased diversity compared to those without older siblings. The researchers suggest that pets and sibling exposure can promote a diverse gut microbiota in infants, which may influence the immune system and allergic disease development later in childhood.

You can read the full article here.

Azad MB, Konya T, et al. Infant gut microbiota and the hygiene hypothesis of allergic disease: impact of household pets and siblings on microbiota composition and diversity. Allergy, Asthma & Clinical Immunology Published online Apr 22 2013.