When I was a scout in Denmark, it was an accepted idea that we would probably eat 7 pounds of dirt each year and that it was somehow good for us. We now know it is may improve our microbiome: "New indicate that new parents shouldn't be afraid of a little dirt — or fur. After monitoring a cohort of nearly 1,200 infants, Lynch and her colleagues found that a dog might be a baby's best friend when it comes to avoiding respiratory disorders2. "The only factor that discriminated high- from low-risk groups was dog ownership," says Lynch (main author). She says that dogs (and, to a lesser extent, cats) "increase the diversity of bacteria and lower the diversity of fungi in the houses where these babies are raised". This finding aligns with other research showing that a rural upbringing or growing up on a farm might yield a richer gut microbiome that reduces the risk of inflammatory respiratory diseases relative to children raised in more urban environments."
The hunt for a healthy microbiome Despite evidence of the gut microbiome's role in human health, researchers are still working out what shapes the community of microbes. By Michael Eisenstein https://www.nature.com/articles/d41586-020-00193-3