Childhood developmental environment affects adult intestinal inflammation levels: preliminary evidence from older adults in the United States.

Background: The Old Friends Hypothesis suggests limited exposure to symbionts during development leads to immune system dysregulation (e.g. allergies, autoimmunity) and inflammatory conditions (e.g. inflammatory bowel disease), with likely sex-specific variation based on exposure risk and sex hormones. Limited research documents how variation in childhood exposures affect older adult health.

Aim: We tested relationships between current intestinal inflammation and childhood environment in 84 older adults (51-88 years) living in Colorado, USA.

Subjects and methods: Faecal calprotectin (FC), a biomarker of intestinal inflammation, was measured from stool samples. Structured interviews assessed farm animal exposure during childhood and childhood environments (urban, suburban, rural) at different age periods (0 to 5, 5 to 10, 10 to 20 years).

Results and conclusions: Farm animal exposure was not significantly associated with FC. Females who grew up in suburban environments, especially between the ages of 5 and 10, had higher FC than females from urban or rural environments (p < 0.05). Males living in urban environments between the ages of 10 and 20 had the lowest FC compared to both other environments (p < 0.05). We found mixed, age- and sex-specific support for the idea that childhood exposures alter risk of inflammatory disease later in life.