The Human Microbiome and the Wisconsin Longitudinal Study

The microbiome is now considered to be as important to human health as the genome. For social and population health scientists, research on the human microbiome may help identify biological mediators that link social conditions to health and mortality. However, research has been hindered by human studies that did not have randomly selected samples and incorporated limited data on social conditions over the life course.

To address these limitations, a team of researchers, including CDHA affiliates Pamela Herd (public affairs; sociology), Nora Cate Schaeffer (sociology), Federico Rey (bacteriology), and Carol Roan (Wisconsin Longitudinal Study), tested the feasibility of integrating data on the gut microbiome with a population-based longitudinal study of aging. Through the collection of stool samples, the researchers added data on the gut microbiome to the Wisconsin Longitudinal Study (WLS). Based on a sample of 1957 Wisconsin high-school graduates, WLS has tracked participants for over sixty years.

For the pilot project, a total of 500 WLS participants were randomly drawn from a constrained sample. Between November 2014 and April 2015, 329 participants completed stool specimens—one of the largest samples to date. In a new paper, “The Influence of Social Conditions across the Life Course on the Human Gut Microbiota: A Pilot Project with the Wisconsin Longitudinal Study,” the researchers documented their data collection processes and lessons learned, including ways to request samples, maximize response rates, and develop collection, transportation, and storage methods.

The inclusion of data like the WLS samples in biodemographic research presents a unique opportunity. Data on the gut microbiome will help provide information on the relationships among specific biological pathways, social conditions, and morbidity and mortality. The data will also help characterize differences in the gut microbiome across different populations and test causality between social conditions, the gut microbiome, and health outcomes.

Support for the WLS microbiome research was provided by a 2016–17 CDHA pilot grant for the project “The Role of Early Life Experiences in Shaping the Gut Microbiome: A Study Incorporating the Microbiome into the Wisconsin Longitudinal Study.”