Nested ecologies of childhood: A microbial turn in developmental theory

Zsuzsa Millei; Nick Lee; Sarah Alminde; Asta Breinholt; Mira Grönroos; Riikka Hohti; Sami Keto; Marja Roslund; Spyros Spyrou; Tuure Tammi; Hanne Warming; Juliene Madureira Ferreira

doi:10.37291/2717638X.202671712

Authors

Zsuzsa Millei Tampere University https://orcid.org/0000-0003-4681-6024
Nick Lee University of Warwick https://orcid.org/0000-0002-6040-9030
Sarah Alminde Roskilde University https://orcid.org/0000-0002-6830-4815
Asta Breinholt Roskilde University https://orcid.org/0000-0002-4706-8470
Mira Grönroos University of Helsinki https://orcid.org/0000-0002-8210-8837
Riikka Hohti University of Helsinki https://orcid.org/0000-0001-6731-589X
Sami Keto Tampere University https://orcid.org/0000-0002-6055-190X
Marja Roslund Natural Resources Institute Finland https://orcid.org/0000-0002-3153-7375
Spyros Spyrou European University Cyprus https://orcid.org/0000-0003-0493-1403
Tuure Tammi University of Oulu https://orcid.org/0000-0002-7582-8887
Hanne Warming Roskilde University https://orcid.org/0000-0003-2212-8876
Juliene Madureira Ferreira Tampere University https://orcid.org/0000-0002-8977-5982

DOI:

https://doi.org/10.37291/2717638X.202671712

Keywords:

Childhood, Bronfenbrenner, Biodiversity, Ecosystem, Microbiome, Child development

Abstract

This article expands Bronfenbrenner’s bioecological model by integrating biological and ecological processes—particularly microbial life—into its core concept of proximal processes. Drawing on host–microbiome research and the concept of the child-as-ecosystem, we reconceptualize the developing person as a multispecies being embedded within nested ecological systems. Through four interdisciplinary encounters—spanning social stratification, family separation, socialisation, and environmental health—we demonstrate how microbial diversity and ecological entanglements shape children’s development, well-being, and learning. We argue that BEM’s human-centered framework must evolve to reflect multispecies interdependencies and ecological realities, especially in the context of biodiversity loss and climate change. This rethinking has direct implications for early childhood education, research, and policy, offering a more ecologically attuned model of development.

References

Aagaard, K., Ma, J., Antony, K. M., Ganu, R., Petrosino, J., & Versalovic, J. (2014). The placenta harbors a unique microbiome. Science Translational Medicine, 6(237), 237ra65. DOI: https://doi.org/10.1126/scitranslmed.3008599

Alanen, L. (2017). Childhood studies and the challenge of ontology. Childhood, 24(2),147–150. DOI: https://doi.org/10.1177/0907568217704539

Appleton, J. (2018). The gut-brain axis: influence of microbiota on mood and mental health. Integrative Medicine: A Clinician’s Journal, 17(4), 28–32.

Berenguer, J. (2007). The effect of empathy in proenvironmental attitudes and behaviors. Environment and Behavior, 39(2), 269–283. DOI: https://doi.org/10.1177/0013916506292937

Blaser, M. J. (2016). Antibiotics, birth mode, and diet shape microbiome maturation during early life. Science Translational Medicine, 8(343), 343ra82. DOI: https://doi.org/10.1126/scitranslmed.aad7121

Boele, S., Van der Graaff, J., De Wied, M., Van der Valk, I. E., Crocetti, E., & Branje, S. (2019). Linking parent–child and peer relationship quality to empathy in adolescence: a multilevel meta-analysis. Journal of Youth and Adolescence, 48(6), 1033–1055. DOI: https://doi.org/10.1007/s10964-019-00993-5

Bokulich, N. A., Chung, J., Battaglia, T., Henderson, N., Jay, M., Li, H., Lieber, A. D., Wu, F., Perez-Perez, G. I., Chen, Y., Schweizer, W., Zheng, X., Contreras, M., Dominguez-Bello, M. G., & Blaser, M. J. (2016). Antibiotics, birth mode, and diet shape microbiome maturation during early life. Science Translational Medicine, 8(343), 343ra82-343ra82. DOI: https://doi.org/10.1126/scitranslmed.aad7121

Bronfenbrenner, U. (1979). The ecology of human development: experiments by nature and design. Harvard University Press. DOI: https://doi.org/10.4159/9780674028845

Bronfenbrenner, U., & Ceci, S. (1994). Nature-nurture reconceptualized in developmental perspective: A bioecological model. Psychological Review, 101(4), 568-5865. DOI: https://doi.org/10.1037/0033-295X.101.4.568

Bronfenbrenner, U., & Morris, P. A. (1998). The ecology of developmental processes. In W. Damon, & R. M. Lerner (Eds.) Handbook of child psychology: Theoretical models of human development (5th ed., pp. 993–1028). John Wiley & Sons, Inc.

Bronfenbrenner, U., & Morris, P. A. (2007). The bioecological model of human development. In W. Damon & R. M. Lerner (Eds.) Handbook of child psychology: Vol. 1. Theoretical models of human development (6th ed., pp. 793–828). John Wiley & Sons. DOI: https://doi.org/10.1002/9780470147658.chpsy0114

Caballero-Flores, G., Pickard, J. M., & Núñez, G. (2023). Microbiota-mediated colonization resistance: mechanisms and regulation. Nature Reviews Microbiology, 21, 347–360. DOI: https://doi.org/10.1038/s41579-022-00833-7

Carrizales, A., Gülseven, Z., & Lannegrand, L. (2023). The mediating role of empathy in the links between relationships with three socialisation agents and adolescents’ prosocial behaviours. Journal of Social and Personal Relationships, 40(9), 2855–2877. DOI: https://doi.org/10.1177/02654075221099652

Costello, E. K., Stagaman, K., Dethlefsen, L., Bohannan, B. J. M., & Relman, D. A. (2012). The application of ecological theory towards an understanding of the human microbiome. Science, 336(6086), 1255–1262. DOI: https://doi.org/10.1126/science.1224203

Cronin, P., Joyce, S. A., O’Toole, P. W., & O’Connor, E. M. (2021). Dietary fibre modulates the gut microbiota. Nutrients, 13(5), 1655. DOI: https://doi.org/10.3390/nu13051655

Csomós, G., Farkas, J. Z., & Kovács, Z. (2024). A GIS-based assessment of different income groups’ access to multiple types of green areas in Budapest, Hungary. Habitat International, 146, 103054. DOI: https://doi.org/10.1016/j.habitatint.2024.103054

Dadvand, P., Nieuwenhuijsen, M. J., Esnaola, M., Forns, J., Basagaña, X., Alvarez-Pedrerol, M., Rivas, I., López-Vicente, M., De Castro Pascual, M., Su, J., Jerrett, M., Querol, X., & Sunyer, J. (2015). Green spaces and cognitive development in primary schoolchildren. Proceedings of the National Academy of Sciences, 112(26), 7937–7942. DOI: https://doi.org/10.1073/pnas.1503402112

de Vries, S., Buijs, A. E., & Snep, R. P. H. (2020). Environmental justice in The Netherlands: Presence and quality of greenspace differ by socioeconomic status of neighbourhoods. Sustainability, 12(15), 5889. DOI: https://doi.org/10.3390/su12155889

Ege, M. J., Mayer, M., Schwaiger, K., Mattes, J., Pershagen, G., van Hage, M., Scheynius, A., Bauer, J., & von Mutius. E. (2012). Environmental bacteria and childhood asthma. Allergy, 67(12), 1565–1571. DOI: https://doi.org/10.1111/all.12028

Elliott, S., & Davis, J. M. (2018). Challenging taken-for-granted ideas in early childhood education: A critique of Bronfenbrenner’s ecological systems theory in the age of post-humanism. In A. Cutter-Mackenzie-Knowles, K. Malone, & E. Barratt Hacking (Eds.) Research handbook on childhoodnature: Assemblages of childhood and nature (pp. 1119–1154). Springer. DOI: https://doi.org/10.1007/978-3-319-67286-1_60

Fodelianakis, S., Valenzuela-Cuevas, A., Barozzi, A., & Daffonchio, D. (2021). Direct quantification of ecological drift at the population level in synthetic bacterial communities. ISME Journal, 15(1), 55–66. DOI: https://doi.org/10.1038/s41396-020-00754-4

Friedl, N., Sporreiter, M., Winkler, C., Heublein, A., Haupt, F., Ziegler, A. G., Bonifacio, E., & Fr1da Study Group (2024). Progression from presymptomatic to clinical type 1 diabetes after COVID-19 infection. JAMA, 332(6), 501–502. DOI: https://doi.org/10.1001/jama.2024.11174

Gabriel, N. (2021). Beyond ‘developmentalism’: A relational and embodied approach to young children's development. Children & Society, 35(1) 49-61. DOI: https://doi.org/10.1111/chso.12381

Garbarino, J. (1993). Childhood: What do we need to know?. Childhood, 1(1), 3-10. DOI: https://doi.org/10.1177/090756829300100102

Gottlieb, G. (1998). Normally Occurring Environmental and Behavioral Influences on Gene Activity. Psychological Review, 105(4), 792-802. DOI: https://doi.org/10.1037/0033-295X.105.4.792-802

Grönroos, M., Jumpponen, A., Roslund, M. I., Nurminen, N., Oikarinen, S., Parajuli, A., Laitinen, O. H., Cinek, O., Kramna, L., Rajaniemi, J., Hyöty, H., Puhakka, R., & Sinkkonen, A. (2024). Using patterns of shared taxa to infer bacterial dispersal in human living environment in urban and rural areas. Applied and Environmental Microbiology, 90(10), e00903-24. DOI: https://doi.org/10.1128/aem.00903-24

Haahtela, T. (2019). A biodiversity hypothesis. Allergy, 74(8), 1445–1456. DOI: https://doi.org/10.1111/all.13763

Haahtela, T., Alenius, H., Lehtimäki, J., Sinkkonen, A., Fyhrquist, N., Hyöty, H., Ruokolainen, L., & Mäkelä, M. J. (2021). Immunological resilience and biodiversity for prevention of allergic diseases and asthma. Allergy, 76(12), 3613-3626. DOI: https://doi.org/10.1111/all.14895

Hanski, I., Von Hertzen, L., Fyhrquist, N., Koskinen, K., Torppa, K., Laatikainen, T., Karisola, P., Auvinen, P., Paulin, L., Mäkelä, M. J., Vartiainen, E., Kosunen, T. U., Alenius, H., & Haahtela, T. (2012). Environmental biodiversity, human microbiota, and allergy are interrelated. Proceedings of the National Academy of Sciences, 109(21), 8334-8339. DOI: https://doi.org/10.1073/pnas.1205624109

Hughes, D. T., & Sperandio, V. (2008). Inter-kingdom signalling: communication between bacteria and their hosts. Nature Reviews Microbiology, 6(2), 111–120. DOI: https://doi.org/10.1038/nrmicro1836

Kalil, A., Ryan, R., & Corey, M. (2012). Diverging destinies: Maternal education and the developmental gradient in time with children. Demography, 49(4), 1361–83. DOI: https://doi.org/10.1007/s13524-012-0129-5

Keto, S., & Foster, R. (2021) Ecosocialization–an ecological turn in the process of socialization. International Studies in Sociology of Education, 30(1-2), 34–52. DOI: https://doi.org/10.1080/09620214.2020.1854826

Khanian, M., Łaszkiewicz, E., & Kronenberg, J. (2024). Exposure to greenery during children’s home–school walks: Socio-economic inequalities in alternative routes. Transportation Research Part D: Transport and Environment, 130, 104162. DOI: https://doi.org/10.1016/j.trd.2024.104162

Kondrashova, A., Reunanen, A., Romanov, A., Karvonen, A., Viskari, H., Vesikari, T., Ilonen, J., Knip, M., & Hyöty, H. (2005). A six-fold gradient in the incidence of type 1 diabetes at the eastern border of Finland. Annals of Medicine, 37(1), 67-72. DOI: https://doi.org/10.1080/07853890410018952

Larsson, D. G. J., & Flach, C. F. (2022). Antibiotic resistance in the environment. Nature Reviews Microbiology, 20, 257–269. DOI: https://doi.org/10.1038/s41579-021-00649-x

Lax, S., Smith, D. P., Hampton-Marcell, J., Owens, S. M., Handley, K. M., Scott, N. M., & Gilbert, J. A. (2014). Longitudinal analysis of microbial interaction between humans and the indoor environment. Science, 345(6200), 1048-1052. DOI: https://doi.org/10.1126/science.1254529

Lee, N. (2013). Childhood and biopolitics: Climate change, life processes, and human futures. Palgrave Macmillan.

Logan, M., & Widdop Quinton, H. (2018). Childhoodnature ecological systems and realities: An outline. In A. Cutter-Mackenzie-Knowles, K. Malone, & E. Barratt Hacking (Eds.) Research handbook on childhoodnature: Assemblages of childhood (pp. 981-993). Springer. DOI: https://doi.org/10.1007/978-3-319-67286-1_54

MacKerron, G., & Mourato, S. (2013). Happiness is greater in natural environments. Global Environmental Change, 23(5), 992-1000. DOI: https://doi.org/10.1016/j.gloenvcha.2013.03.010

Margulis, L., & Sagan, D. (2002). Acquiring genomes: A theory of the origins of species first edition. Basic Books.

McFall-Ngai, M. (2017). Noticing microbial worlds: The postmodern synthesis in biology. In A. L. Tsing, N. Bubandt, E. Gan, & H. A. Swanson (Eds.), Arts of Living on a Damaged Planet: Ghosts and Monsters of the Anthropocene (pp. 51-70). University of Minnesota Press.

Millei, Z., Spyrou, S., Rosslund, M., Breinholt, A., Tammi, T., Conklin, B., Lee, N., Alminde, S., & Warming, H. (2025). Child ecologies in a microbial world: A new imperative for childhood studies. Journal of Childhood Studies, 50(1), 34-52 https://journals.uvic.ca/index.php/jcs/article/view/21918 DOI: https://doi.org/10.18357/jcs501202521918

Nemergut, D. R., Schmidt, S. K., Fukami, T., O’Neill, S. P., Bilinski, T. M., Stanish, L. F., Knelman, J. E., Darcy, J. L., Lynch, R. C., Wickey, P., & Ferrenberg, S. (2013). Patterns and processes of microbial community assembly. Microbiology and Molecular Biology Reviews, 77(3), 342–356. DOI: https://doi.org/10.1128/MMBR.00051-12

Nisbet, E. K., Zelenski, J. M., & Murphy, S. A. (2009). The nature relatedness scale linking individuals’ connection with nature to environmental concern and behavior. Environment and Behavior, 41(5), 715-740. DOI: https://doi.org/10.1177/0013916508318748

Preston, S. D., & de Waal, F. B. (2002). Empathy: Its ultimate and proximate bases. Behavioral and Brain Sciences, 25(1), 1–20. DOI: https://doi.org/10.1017/S0140525X02000018

Prout, A. (2005) The future of childhood: Towards the interdisciplinary study of children. Routledge.

Puhakka, R., Rantala, O., Roslund, M. I., Rajaniemi, J., Laitinen, O. H., Sinkkonen, A., & the ADELE Research Group. (2019). Greening of daycare yards with biodiverse materials affords well-being, play and environmental relationships. International Journal of Environmental Research and Public Health, 16(16), 2948. DOI: https://doi.org/10.3390/ijerph16162948

Rieder, R., Wisniewski, P. J., Alderman, B. L., & Campbell, S. C. (2017). Microbes and mental health: A review. Brain, Behaviour and Immunity, 66, 9–17. DOI: https://doi.org/10.1016/j.bbi.2017.01.016

Rook, G. A. W. (2003). Regulation of the immune system by biodiversity from the natural environment: An ecosystem service essential to health. Proceedings of the National Academy of Sciences of the United States of America, 100(suppl 2), 9840–9847.

Rosa, E. M., & Tudge, J. (2013) Urie Bronfenbrenner's Theory of Human Development: Its evolution from ecology to bioecology. Journal of Family Theory & Review, 5(4), 243-258. DOI: https://doi.org/10.1111/jftr.12022

Roslund, M. I., Rantala, S., Oikarinen, S., Puhakka, R., Hui, N., Parajuli, A., Laitinen, O. H., Hyöty, H., Rantalainen, A.-L. Sinkkonen, A., & the ADELE team. (2019). Endocrine disruption and commensal bacteria alteration associated with gaseous and soil PAH contamination among daycare children. Environment International, 130, 104894. DOI: https://doi.org/10.1016/j.envint.2019.06.004

Roslund, M., Parajuli, A., Hui, N., Puhakka, R., Grönroos, M., Soininen, L., Nurminen, N., Oikarinen, S., Cinek, O., Kramna, L., Schroderus, A.-M., Laitinen, O., Kinnunen, T., Hyöty, H., & Sinkkonen, A., (2022). A Placebo-controlled double-blinded test of the biodiversity hypothesis of immune-mediated diseases: Environmental microbial diversity elicits changes in cytokines and increase in T regulatory cells in young children. Ecotoxicology and Environmental Safety, 242(1), 12 113900. DOI: https://doi.org/10.1016/j.ecoenv.2022.113900

Rubio-Cabañez, M. (2024). Stratifying cities: The effect of outdoor recreation areas on children’s well-being. European Sociological Review, 41(3), 472–486. DOI: https://doi.org/10.1093/esr/jcae028

Ryan, K. W. (2012). The new wave of childhood studies: Breaking the grip of bio-social dualism?. Childhood, 19(4), 439–452. DOI: https://doi.org/10.1177/0907568211427612

Sarkar, A., Harty, S., Lehto, S. M., Moeller, A. H., Dinan, T. G., Dunbar, R. I., & Burnet, P. W. (2018). The microbiome in psychology and cognitive neuroscience. Trends in Cognitive Sciences, 22(7), 611–636. DOI: https://doi.org/10.1016/j.tics.2018.04.006

Schnegg, M., & Breyer, T. (2022). Empathy beyond the human. The social construction of a multispecies world. Ethnos, 89(5), 848-869. DOI: https://doi.org/10.1080/00141844.2022.2153153

Singer, T., & Lamm, C. (2009). The social neuroscience of empathy. Annals of the New York Academy of Sciences, 1156(1), 81–96. DOI: https://doi.org/10.1111/j.1749-6632.2009.04418.x

Song, S. J., Lauber, C., Costello, E. K., Lozupone, C. A., Humphrey, G., Berg-Lyons, D., Caporaso, J. G., Knights, D., Clemente, J. C., Nakielny, S., Gordon, J. I., Fierer, N., & Knight, R. (2013). Cohabiting family members share microbiota with one another and with their dogs. eLife, 2, e00458. DOI: https://doi.org/10.7554/eLife.00458

Sprockett, D., Fukami, T., & Relman, D. A. (2018). Role of priority effects in the early-life assembly of the gut microbiota. Nature Reviews Gastroenterology & Hepatology, 15, 197–205. DOI: https://doi.org/10.1038/nrgastro.2017.173

Stanger, N. (2011). Moving “eco” back into socio-ecological models: A proposal to reorient ecological literacy into human development models and school systems. Human Ecology Review, 18(2), 167–173.

Stryker, R., Boddy, J., Bragg, S., & Sims-Schouten, W. (2019). The future of childhood studies. Children & Society, 33(4), 301-308. DOI: https://doi.org/10.1111/chso.12345

Tammi, T., Hohti, R., & Rautio, P. (2023). From child–animal relations to multispecies assemblages and other-than-human childhoods. Barn, 41(2–3), 1–17. DOI: https://doi.org/10.23865/barn.v41.5475

Tatlow-Golden, M., & Montgomery, H. (2021). Childhood Studies and child psychology: Disciplines in dialogue?. Children & society 35(1), 3-17. DOI: https://doi.org/10.1111/chso.12384

Tsing, A. (2013). More-than-human sociality: A call for critical description. In K. Hastrup (Ed.), Anthropology and nature (pp. 27-42). Routledge.

United Nations Department of Economic and Social Affairs Population Division (2019). World Urbanization Prospects 2018: Highlights (ST/ESA/SER.A/421). https://population.un.org/wup/assets/WUP2018-Highlights.pdf

van Dooren, T., Kirksey, E., & Münster, U. (2016). Multispecies studies: Cultivating arts of attentiveness. Environmental Humanities 8(1), 1–23. DOI: https://doi.org/10.1215/22011919-3527695

Vellend, M. (2010). Conceptual synthesis in community ecology. The Quarterly Review of Biology, 85(2), 183–206. DOI: https://doi.org/10.1086/652373

Warming, H., & Alminde, S. (2025). Divorcescapes: family conflict and children’s lived spaces. Child & Family Social Work. DOI: https://doi.org/10.1111/cfs.70051

Wilson, A. S., Koller, K. R., Ramaboli, M. C., Nesengani, L. T., Ocvirk, S., Chen, C., Flanagan, C. A., Sapp, F. R., Merritt, Z. T., Bhatti, F., Thomas, T. K., & O’Keefe, S. J. D. (2020). Diet and the human gut microbiome: An International Review. Digestive Diseases and Sciences, 65, 723–740. DOI: https://doi.org/10.1007/s10620-020-06112-w

Yu, M., Yu, B., & Chen, D. (2024). The effects of gut microbiota on appetite regulation and the underlying mechanisms. Gut Microbes, 16(1), 2414796. DOI: https://doi.org/10.1080/19490976.2024.2414796

Zahavi, D., & Michael, J. (2018). Beyond Mirroring: 4E Perspectives on Empathy. In A. Newen, L. de Bruin, & S. Gallagher (Eds.), The Oxford Handbook of 4e Cognition (pp. 589-606). Oxford University Press. DOI: https://doi.org/10.1093/oxfordhb/9780198735410.013.29