Biodiversity and human health: A scoping review and examples of underrepresented linkages

Mounting evidence supports the connections between exposure to environmental typologies(such as green and blue spaces)and human health. However, the mechanistic links that connect biodiversity (the variety of life) and human health, and the extent of supporting evidence remain less clear. Here, we undertook a scoping review to map the links between biodiversity and human health and summarise the levels of associated evidence using an established weight of evidence framework. Distinct from other reviews, we provide additional context regarding the environment-microbiome-health axis, evaluate the environmental buffering pathway (e.g., biodiversity impacts on air pollution), and provide examples of three under- or minimally-represented linkages. The examples are (1) biodiversity and Indigenous Peoples' health, (2) biodiversity and urban social equity, and (3) biodiversity and COVID-19. We observed a moderate level of evidence to support the environmental microbiota-human health pathway and a moderate-high level of evidence to support broader nature pathways (e.g., greenspace) to various health outcomes, from stress reduction to enhanced wellbeing and improved social cohesion. However, studies of broader nature pathways did not typically include specific biodiversity metrics, indicating clear research gaps. Further research is required to understand the connections and causative pathways between biodiversity (e.g., using metrics such as taxonomy, diversity/richness, structure, and function) and health outcomes. There are well-established frameworks to assess the effects of broad classifications of nature on human health. These can assist future research in linking biodiversity metrics to human health outcomes. Our examples of underrepresented linkages highlight the roles of biodiversity and its loss on urban lived experiences, infectious diseases, and Indigenous Peoples' sovereignty and livelihoods. More research and awareness of these socioecological interconnections are needed.

Current methods for evaluating people's exposure to green space: A scoping review

People's exposure to green space is a critical link between urban green space and urban residents' health. Since green space may affect human health through multiple pathways regarding diverse human health outcomes, the measurement of people's exposure to green space must be tailored to concrete study contexts and research questions. In this scoping review, we systematically categorized the available green space representations and metrics in the last two decades that can be used to derive people's exposure to green space regarding different research topics. A three-phase systematic review was conducted after a generalized search of relevant research articles from the three most-used publication databases, namely Scopus, the Web of Science, and PubMed. We identified 260 research articles that particularly discuss green space representations and metrics. We further developed a multi-pathway framework to articulate the complicated context issues in green space studies. We categorized the most relevant green space representations and metrics into five groups, including green space indices, the delineation, inventory, and usage of green space, the spatiotemporal evolution of green space, the attributes and components of green space, and the green space landscape and fragmentation. Finally, we discussed the inter-conversion between different green space representations and metrics, the "mobility-turn" in green space studies and how it may affect the derivation of people's exposure to green space, and other potential methodological issues in measuring people's exposure to green space. Our scoping review provides the most comprehensive framework and categories for deriving people's exposure to green space to date, which may strongly support a broad range of studies that concern green space's health effects.

The relationship between perinatal circadian rhythm and postnatal depression: an overview, hypothesis, and recommendations for practice

Postnatal depression (PND) is an important public health problem with far-reaching consequences for mothers, families, and society. Current treatment approaches tend to focus on the depressive symptoms of the mother. We propose the need for a shift in the conceptualisation of PND and its management, by focusing on circadian rhythm as an early manifestation of mother-infant synchrony. We have reviewed the relevant interdisciplinary literature to formulate a hypothesis and suggest recommendations for practice. We hypothesise that, after a mother’s circadian rhythm becomes ‘desynchronised’ immediately following birth, persistence of this disruption is implicated in the development of PND. This has important implications for novel treatment strategies in the critical and vulnerable postnatal period, for example the use of outdoor-based interventions and light.

The Microbiome of the Built Environment: The Nexus for Urban Regeneration for the Cities of Tomorrow

Built environments are, for most of us, our natural habitat. In the last 50 years, the built-up area has more than doubled, with a massive biodiversity loss. The undeniable benefits of a city providing all the basic needs to a growing population showed longer-term and less obvious costs to human health: autoimmune and non-communicable diseases, as well as antimicrobial resistance, have reached unprecedented and alarming levels. Humans coevolved with microbes, and this long-lasting alliance is affected by the loss of connection with natural environments, misuse of antibiotics, and highly sanitized environments. Our aim is to direct the focus onto the microbial communities harbored by the built environments we live in. They represent the nexus for urban regeneration, which starts from a healthy environment. Planning a city means considering, in a two-fold way, the ecosystem health and the multidimensional aspects of wellbeing, including social, cultural, and aesthetic values. The significance of this perspective is inspiring guidelines and strategies for the urban regeneration of the cities of tomorrow, exploiting the invaluable role of microbial biodiversity and the ecosystem services that it could provide to create the robust scientific knowledge that is necessary for a bioinformed design of buildings and cities for healthy and sustainable living.

Reciprocal Inclusion of Microbiomes and Environmental Justice Contributes Solutions to Global Environmental Health Challenges

Generations of colonialism, industrialization, intensive agriculture, and anthropogenic climate change have radically altered global ecosystems and by extension, their environmental microbiomes. The environmental consequences of global change disproportionately burden racialized communities, those with lower socioeconomic status, and other systematically underserved populations. Environmental justice seeks to balance the relationships between environmental burden, beneficial ecosystem functions, and local communities. Given their direct links to human and ecosystem health, microbes are embedded within social and environmental justice. Considering scientific and technological advances is becoming an important step in developing actionable solutions to global equity challenges. Here we identify areas where inclusion of microbial knowledge and research can support planetary health goals. We offer guidelines for strengthening a reciprocal integration of environmental justice into environmental microbiology research. Microbes form intimate relationships with the environment and society, thus microbiologists have numerous and unique opportunities to incorporate equity into their research, teaching, and community engagement.

Ecohealth Villages: A Framework for an Ecosystem Approach to Health in Human Settlements

As life emerged on Earth, it began to affect its environments. It still does. The complex interactions between living things and their environments mediate the character of both. Today, this is apparent in the global impacts humans have made on ecosystems, with resultant reciprocal impacts on human health. This paper is concerned with that reciprocity, which may be considered as a link between ecosystems and human populations. We will distinguish an ecosystem approach to human health—or ecohealth—from One Health and planetary health perspectives. We will also propose a conceptual framework that can be used to distinguish human settlements as Ecohealth Villages. Broadly defined, an Ecohealth Village is a settlement that recognizes the interactions between healthy ecosystems and the health of people who live, work, learn, and play in it. The key principles of an Ecohealth Villages are as follows: community ownership, ecological restoration, sustainability, social and gender equity, integrated perspectives, and traditional practices and knowledge. Together, they support a holistic, ecosystem approach to health in human settlements, as demonstrated in case studies from Mexico and Aotearoa New Zealand.

Microbiota composition is moderately associated with greenspace composition in a UK cohort of twins

Exposure to natural environments, known as greenspace, appears to positively influence health, yet the mechanisms are unclear. Given that gut microbiota are associated with inflammatory disorders more prevalent in urban areas and individuals with lower greenspace exposure, microbiota may act as a mediator between greenspace and health. Using 2443 participants of the TwinsUK cohort, microbiota differences were compared in relation to rural/urban living and with quantiles of area-level greenspace at three different neighbourhood distances: 800 m, 3000 m and 5000 m. Using microbiota data captured from faecal samples using 16S rRNA marker gene sequencing, small compositional differences in association with 3000 m greenspace (p = 0.003) in models adjusted for confounders of microbiota variance (sequencing depth, antibiotics use, body mass index, frailty, age, diet, region and socioeconomic variables) were observed. Differences in abundances of genus were observed for all measures of greenspace in adjusted models; a key pathogenic genus was increased in abundance in association with urbanicity (Escherichia/Shigella, logFC = 0.73742, padj <0.001). Further, utilising the twin structure, within-pair differences in microbiota composition were compared and associations with 800 m greenspace observed (factor level significance in association with greatest difference, β = 0.08, p = 0.0162) as were differences in Escherichia/Shigella. The microbiota signature of those with a greater exposure to greenspace, but not necessarily explicitly rural individuals, was distinct from other individuals, suggesting microbiota as a potential mediator for greenspace and health.

Living through multispecies societies: Approaching the microbiome with Imanishi Kinji

Recent research about the microbiome points to a picture in which we, humans, are 'living through' nature, and nature itself is living in us. Our bodies are hosting-and depend on-the multiple species that constitute human microbiota. This article will discuss current research on the microbiome through the ideas of Japanese ecologist Imanishi Kinji (1902-1992). First, some of Imanishi's key ideas regarding the world of living beings and multispecies societies are presented. Second, seven types of relationships concerning the human microbiome, human beings, and the environment are explored. Third, inspired by Imanishi's work, this paper develops the idea of dynamic, porous, and complex multispecies societies in which different living beings or species are codependent on others, including microbiota and human beings.

Twenty Important Research Questions in Microbial Exposure and Social Equity

Social and political policy, human activities, and environmental change affect the ways in which microbial communities assemble and interact with people. These factors determine how different social groups are exposed to beneficial and/or harmful microorganisms, meaning microbial exposure has an important socioecological justice context. Therefore, greater consideration of microbial exposure and social equity in research, planning, and policy is imperative. Here, we identify 20 research questions considered fundamentally important to promoting equitable exposure to beneficial microorganisms, along with safeguarding resilient societies and ecosystems. The 20 research questions we identified span seven broad themes, including the following: (i) sociocultural interactions; (ii) Indigenous community health and well-being; (iii) humans, urban ecosystems, and environmental processes; (iv) human psychology and mental health; (v) microbiomes and infectious diseases; (vi) human health and food security; and (vii) microbiome-related planning, policy, and outreach. Our goal was to summarize this growing field and to stimulate impactful research avenues while providing focus for funders and policymakers.

Environmental physiotherapy and the case for multispecies justice in planetary health

Background:Global environmental change is fundamentally altering the composition and functioning of our planetary ecosystem. Effectively presenting the largest threat to the health of present and future generations, these changes and their health impacts are forcing us to think and practice healthcare in much broader terms than ever before. Objective:In this article, we provide an early outline for a radically otherwise, yet strangely familiar, environmental physiotherapy developed through a succession of carefully developed arguments. Discussion:We show how an underpinning belief in human exceptionalism has engendered an exploitative relationship with our natural planetary environment that has both shaped Western science and healthcare and led to our current environmental health crisis. Building on the dependence of human health on our planetary ecosystem, approaches like planetary health hold great promise for a corresponding, paradigmatic turn in healthcare. They fall short of this however, where they perpetuate anthropocentric interests and interventionist practices that have underpinned healthcare to date. Drawing on ethical and post-human philosophies we argue against human exceptionalism and for a solidarity that includes other-than-humans as the primary characteristic of planetary existence. Conclusion:Building on this foundation, we provide an early outline for a radically otherwise, yet strangely familiar, environmental physiotherapy, grounded in ecological awareness, multispecies justice, and a range of consonant practices of passivity and accompaniment, conceived as an alternative to the commonplace interventionism of healthcare.

The Effects of Anthropogenic Sound and Artificial Light Exposure on Microbiomes: Ecological and Public Health Implications

Globally, anthropogenic sound and artificial light pollution have increased to alarming levels. Evidence suggests that these can disrupt critical processes that impact ecosystems and human health. However, limited focus has been given to the potential effects of sound and artificial light pollution on microbiomes. Microbial communities are the foundations of our ecosystems. They are essential for human health and provide myriad ecosystem services. Therefore, disruption to microbiomes by anthropogenic sound and artificial light could have important ecological and human health implications. In this mini-review, we provide a critical appraisal of available scientific literature on the effects of anthropogenic sound and light exposure on microorganisms and discuss the potential ecological and human health implications. Our mini-review shows that a limited number of studies have been carried out to investigate the effects of anthropogenic sound and light pollution on microbiomes. However, based on these studies, it is evident that anthropogenic sound and light pollution have the potential to significantly influence ecosystems and human health via microbial interactions. Many of the studies suffered from modest sample sizes, suboptimal experiments designs, and some of the bioinformatics approaches used are now outdated. These factors should be improved in future studies. This is an emerging and severely underexplored area of research that could have important implications for global ecosystems and public health. Finally, we also propose the photo-sonic restoration hypothesis: does restoring natural levels of light and sound help to restore microbiomes and ecosystem stability?

Exposure to airborne bacteria depends upon vertical stratification and vegetation complexity

Exposure to biodiverse aerobiomes supports human health, but it is unclear which ecological factors influence exposure. Few studies have investigated near-surface green space aerobiome dynamics, and no studies have reported aerobiome vertical stratification in different urban green spaces. We used columnar sampling and next generation sequencing of the bacterial 16S rRNA gene, combined with geospatial and network analyses to investigate urban green space aerobiome spatio-compositional dynamics. We show a strong effect of habitat on bacterial diversity and network complexity. We observed aerobiome vertical stratification and network complexity that was contingent on habitat type. Tree density, closer proximity, and canopy coverage associated with greater aerobiome alpha diversity. Grassland aerobiomes exhibited greater proportions of putative pathogens compared to scrub, and also stratified vertically. We provide novel insights into the urban ecosystem with potential importance for public health, whereby the possibility of differential aerobiome exposures appears to depend on habitat type and height in the airspace. This has important implications for managing urban landscapes for the regulation of aerobiome exposure.