The Influence of Social Conditions Across the Life Course on the Human Gut Microbiota: A Pilot Project With the Wisconsin Longitudinal Study

Abstract

Objective: To test the feasibility of collecting and integrating data on the gut microbiome into one of the most comprehensive longitudinal studies of aging and health, the Wisconsin Longitudinal Study (WLS). The long-term goal of this integration is to clarify the contribution of social conditions in shaping the composition of the gut microbiota late in life. Research on the microbiome, which is considered to be of parallel importance to human health as the human genome, has been hindered by human studies with nonrandomly selected samples and with limited data on social conditions over the life course.

Methods: No existing population-based longitudinal study had collected fecal specimens. Consequently, we created an in-person protocol to collect stool specimens from a subgroup of WLS participants.

Results: We collected 429 stool specimens, yielding a 74% response rate and one of the largest human samples to date.

Discussion: The addition of data on the gut microbiome to the WLS-and to other population based longitudinal studies of aging-is feasible, under the right conditions, and can generate innovative research on the relationship between social conditions and the gut microbiome.

Keywords: Biodemography; Health disparities; Survey methods.

Figure 1.

Whole sample stool-collection kits. (a) Off-the shelf kit. (b) Customized kit used for WLS. WLS = Wisconsin Longitudinal Study.

Figure 2.

Nanocool cooling system container with customized foam insert and container. (a) Nanocool self-contained cooling system with cooling cartridge taken out and inverted on top to show the activation buttons. (b) Inside of the Nanocool self-contained cooling system with stool sample container placed into custom Styrofoam insert. (c) Cooled ice pack placed on top of stool sample container began cooling the sample until the activated cooling cartridge lowered the temperature inside the Nanocool container.

Figure 3.

Intake lab area at UWSC headquarters which contained a lockable super freezer capable of −80°C with a CO₂ backup system in case of a power failure, a lockable refrigerator, a steel work table, and a dedicated computer workstation. Not pictured here is the adjacent eyewash station and steel lockers for lab coats and staff safety glasses.