Wednesday, August 14, 2019: 3:20 PM
L015/019, Kentucky International Convention Center
Mauna Dasari1, David Jansen1, Trevor Gould2, Laura E. Grieneisen2, Johannes R Björk1, Jean-Christophe Grenier3, Vania Yotova3, Neil R. Gottel4, Jack A. Gilbert4, Luis Barreiro3, Ran Blekhman2,5, Jeanne Altmann6, Susan C. Alberts7,8, Jenny Tung7,8 and Elizabeth A. Archie1, (1)Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, (2)Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, (3)CHU Sainte Justine Research Center, Université de Montréal, Montréal, QC, Canada, (4)Pediatrics and Scripps Institute of Oceanography, University of California San Diego, La Jolla, CA, (5)Department of Ecology, Evolution, and Behavior, University of Minnesota, Minneapolis, MN, (6)Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, (7)Department of Biology, Duke University, Durham, NC, (8)Department of Evolutionary Anthropology, Duke University, Durham, NC
Background/Question/Methods: Host-associated microbiomes are highly individualized, dynamic ecosystems that fluctuate over time and are thought to be important to host health and physical functioning. Cross-sectional studies on humans indicate changes in gut microbial composition in early life and during senescence. However, it is unclear if these changes are caused by intrinsic factors (e.g. changes to host immunity with age) or extrinsic factors (e.g. changes to human medications and lifestyles in old age). Therefore, it is important to test for gut microbial aging in wild animals that do not undergo as pronounced changes in lifestyle in old age. To advance our understanding of mammalian gut microbiome dynamics, we test whether the gut microbiome exhibits predictable age-related changes in composition, diversity, and stability, analogous to “successional” stages that correlate with host age. We address this question using a unique longitudinal data set spanning 13,563 freeze-dried fecal samples from 479 known individual baboons (
Papio cynocephalus) over the course of 14 years. These samples are complemented by concurrently collected demographic, endocrinological, and social behavioral data on the same animals, allowing us to test whether these factors predict inter-individual differences in gut microbial aging.
Results/Conclusions: Data were analyzed across lifespan and within age group: “juvenile” spanned birth to sexual maturation, “adulthood” spanned sexual maturation to “geriatric”, defined as the period where ~80% of the same-sex population has died. Age was a significant predictor of gut microbial alpha diversity during juvenile and geriatric periods. During adulthood, age was not a significant predictor of alpha diversity. Across lifespan, age was a significant predictor of alpha diversity in all models, but the addition of hormonal and social predictors reduced its effect size. Age was a significant predictor of stability (coefficient of variation in alpha diversity) when modelled with environmental variables (diet, rainfall, group identity), but the effect disappeared with the addition of social variables. Additionally, age was not a significant predictor of a change in stability within each age class. By determining the factors that influence gut microbial diversity, these results help characterize normal mammalian gut dynamics, specifically how gut microbial communities change with age in a wild primate population. Understanding how the microbiome ages with the host, and what social and environmental markers are informative of microbial aging, will be important for understanding the role of host physiology and development on the commensal microbial communities they host.
