Caitlin A Selway1, Jacob G Mills2, Philip Weinstein3, Chris Skelly4, Sudesh Yadav5, Andrew Lowe6, Martin F Breed7, Laura S Weyrich8. 1. Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia. Electronic address: caitlin.selway@adelaide.edu.au. 2. School of Biological Sciences and the Environment Institute, University of Adelaide, Adelaide, SA 5005, Australia. Electronic address: jacob.mills@adelaide.edu.au. 3. School of Biological Sciences and the Environment Institute, University of Adelaide, Adelaide, SA 5005, Australia. Electronic address: philip.weinstein@adelaide.edu.au. 4. Public Health Dorset, Dorset County Council, Dorchester DT1 1TP, UK. Electronic address: wchris.skelly@gmail.com. 5. School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address: syadav@mail.jnu.ac.in. 6. School of Biological Sciences and the Environment Institute, University of Adelaide, Adelaide, SA 5005, Australia. Electronic address: andrew.lowe@adelaide.edu.au. 7. College of Science and Engineering, Flinders University, Bedford Park, SA 5042, Australia. Electronic address: martin.breed@flinders.edu.au. 8. Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia; Department of Anthropology, The Pennsylvania State University, University Park, PA 16802, USA; Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address: lsw132@psu.edu.
Abstract
BACKGROUND: In industrialized countries, non-communicable diseases have been increasing in prevalence since the middle of the 20th century. While the causal mechanisms remain poorly understood, increased population density, pollution, sedentary behavior, smoking, changes in diet, and limited outdoor exposure have all been proposed as significant contributors. Several hypotheses (e.g. Hygiene, Old Friends, and Biodiversity Hypotheses) also suggest that limited environmental microbial exposures may underpin part of this rise in non-communicable diseases. In response, the Microbiome Rewilding Hypothesis proposes that adequate environmental microbial exposures could be achieved by restoring urban green spaces and could potentially decrease the prevalence of non-communicable diseases. However, the microbial interactions between humans and their surrounding environment and the passaging of microbes between both entities remains poorly understood, especially within an urban context. RESULTS: Here, we survey human skin (n = 90 swabs) and nasal (n = 90 swabs) microbiota of three subjects that were exposed to air (n = 15), soil (n = 15), and leaves (n = 15) from different urban green space environments in three different cities across different continents (Adelaide, Australia; Bournemouth, United Kingdom; New Delhi, India). Using 16S ribosomal RNA metabarcoding, we examined baseline controls (pre-exposure) of both skin (n = 16) and nasal (n = 16) swabs and tracked microbiota transfer from the environment to the human body after exposure events. Microbial richness and phylogenetic diversity increased after urban green space exposure in skin and nasal samples collected in two of the three locations. The microbial composition of skin samples also became more similar to soil microbiota after exposure, while nasal samples became more similar to air samples. Nasal samples were more variable between sites and individuals than skin samples. CONCLUSIONS: We show that exposure to urban green spaces can increase skin and nasal microbial diversity and alter human microbiota composition. Our study improves our understanding of human-environmental microbial interactions and suggests that increased exposure to diverse outdoor environments may increase the microbial diversity, which could lead to positive health outcomes for non-communicable diseases.
BACKGROUND: In industrialized countries, non-communicable diseases have been increasing in prevalence since the middle of the 20th century. While the causal mechanisms remain poorly understood, increased population density, pollution, sedentary behavior, smoking, changes in diet, and limited outdoor exposure have all been proposed as significant contributors. Several hypotheses (e.g. Hygiene, Old Friends, and Biodiversity Hypotheses) also suggest that limited environmental microbial exposures may underpin part of this rise in non-communicable diseases. In response, the Microbiome Rewilding Hypothesis proposes that adequate environmental microbial exposures could be achieved by restoring urban green spaces and could potentially decrease the prevalence of non-communicable diseases. However, the microbial interactions between humans and their surrounding environment and the passaging of microbes between both entities remains poorly understood, especially within an urban context. RESULTS: Here, we survey human skin (n = 90 swabs) and nasal (n = 90 swabs) microbiota of three subjects that were exposed to air (n = 15), soil (n = 15), and leaves (n = 15) from different urban green space environments in three different cities across different continents (Adelaide, Australia; Bournemouth, United Kingdom; New Delhi, India). Using 16S ribosomal RNA metabarcoding, we examined baseline controls (pre-exposure) of both skin (n = 16) and nasal (n = 16) swabs and tracked microbiota transfer from the environment to the human body after exposure events. Microbial richness and phylogenetic diversity increased after urban green space exposure in skin and nasal samples collected in two of the three locations. The microbial composition of skin samples also became more similar to soil microbiota after exposure, while nasal samples became more similar to air samples. Nasal samples were more variable between sites and individuals than skin samples. CONCLUSIONS: We show that exposure to urban green spaces can increase skin and nasal microbial diversity and alter human microbiota composition. Our study improves our understanding of human-environmental microbial interactions and suggests that increased exposure to diverse outdoor environments may increase the microbial diversity, which could lead to positive health outcomes for non-communicable diseases.
Authors: Sally L Bornbusch; Lydia K Greene; Sylvia Rahobilalaina; Samantha Calkins; Ryan S Rothman; Tara A Clarke; Marni LaFleur; Christine M Drea Journal: Anim Microbiome Date: 2022-04-28
Authors: Jake M Robinson; Christian Cando-Dumancela; Craig Liddicoat; Philip Weinstein; Ross Cameron; Martin F Breed Journal: Environ Health Perspect Date: 2020-11-25 Impact factor: 9.031
Authors: Jake M Robinson; Christian Cando-Dumancela; Rachael E Antwis; Ross Cameron; Craig Liddicoat; Ravin Poudel; Philip Weinstein; Martin F Breed Journal: Sci Rep Date: 2021-05-04 Impact factor: 4.379
Authors: Jake M Robinson; Nicole Redvers; Araceli Camargo; Christina A Bosch; Martin F Breed; Lisa A Brenner; Megan A Carney; Ashvini Chauhan; Mauna Dasari; Leslie G Dietz; Michael Friedman; Laura Grieneisen; Andrew J Hoisington; Patrick F Horve; Ally Hunter; Sierra Jech; Anna Jorgensen; Christopher A Lowry; Ioana Man; Gwynne Mhuireach; Edauri Navarro-Pérez; Euan G Ritchie; Justin D Stewart; Harry Watkins; Philip Weinstein; Suzanne L Ishaq Journal: mSystems Date: 2022-01-04 Impact factor: 6.496