Probiotic Environmentalities: Rewilding with Wolves and Worms

A Probiotic Turn

Securing the human through the control of unruly ecologies is one of the defining objectives of the period becoming known as the Anthropocene. Bodies have been purified, homes sanitized and some environments made safe, productive and orderly. Scientific and political developments in the 19th and 20th centuries led to the eradication of diseases, economic growth and food surpluses. Modern hygiene has made some lives better. But in recent decades environmental and medical experts have argued that this ‘antibiotic’ approach has become excessive. It is suggested that obsessions with purity, division, simplicity and control are driving the emergence of new pathologies.

Environmental scientists have flagged the ‘pathologies’ of modern modes of natural resource management (Holling and Meffe, 1996; Hinchliffe et al., 2016). They argue that the eradication of species and the rationalization of environmental processes (like fire, flood and disease) undermine the functionality of ecological systems. Such thinking has been echoed in more recent discussions of the human microbiome (HMP, 2012). Emerging maps of the microbial life in us are beginning to specify established concerns that modern lifestyles have degraded our inner ecologies. We are warned that ‘missing microbes’ (Blaser, 2014) might account for the dramatic recent increases in allergic, inflammatory and autoimmune diseases.

In response to these concerns, there is a now a growing interest across a range of policy domains in the ‘probiotic’ introduction of formerly taboo entities into our bodies, homes, cities and the wider countryside. I use the label probiotic in an expansive sense to encompass interventions that are explicitly framed in contrast to modern, antibiotic approaches to health and environmental management. Examples extend from the rise of ‘probiotic’ diets (e.g. Sonnenburg and Sonnenburg, 2015), to established forms of ‘organic’ farming and ‘biological’ means for pest control (Hajek, 2004), to the rise of ‘rewilding’ in nature conservation (Lorimer et al., 2015) and practices of ‘managed realignment’ in flood defense (Esteves, 2014). These practices are still marginal, they are contested, and they differ in important ways. But this probiotic turn is intellectually and politically significant for understanding late modern human-environment relations.

To date there has been little systematic research on these trends and the mode of government they represent. This article begins to address this gap. To do so it compares developments in two sets of case studies, which it takes as exemplary of the probiotic turn as it is manifested in the ‘macro’ and the ‘micro’ biome. The first is ‘rewilding’ and the introduction of ecologically significant ‘keystone species’ (like wolves) for landscape-scale nature conservation. The second is ‘helminthic therapy’ and the introduction of parasitic worms into the human body to address autoimmune and inflammatory diseases.

Having outlined these examples, the article reflects on three broad themes that help specify the character of the probiotic turn. It first identifies components of a common ontology associated with these interventions. Here human bodies and natural landscapes comprise dynamic and unstable ecologies. These ecologies are marked by anthropogenic absences, which have tipped them across thresholds into less desirable states. Second, the article draws on recent literatures on biopolitics and biosecurity, to identify a probiotic ‘environmentality’ (after Foucault, 2010) – or ‘environmental’ mode of biopower – associated with deliberate efforts to engineer ecologies through the introduction of keystone species. It identifies common techniques through which such species are used to reconfigure their target ecology, tipping these across thresholds to secure desired functions. Third, the article offers a set of criteria for critically evaluating the political and ecological objectives of these interventions, focusing on the degree to which they ‘sustain’ or ‘transform’ (after Nelson, 2014) the unequal, proprietorial and anthropocentric character of prevalent forms of late modern biopolitics. In conclusion, the article reflects on the potential of the probiotic turn for developing hospitable government within and beyond the Anthropocene.

Rewilding

Critics have argued that 20th-century nature conservation was too conservative in its efforts to fix ecologies in the face of rapid land use change (Hobbs et al., 2013). They argue that this model of conservation has had limited success and might be pathological as a response to the fast-changing ecologies of the Anthropocene (for discussion see Marris, 2011, and critical responses in Wuerthner et al., 2014). A growing number of ecologists and conservationists now describe a planet of ‘anthromes’ (Ellis, 2011) or ‘novel ecosystems’ (Hobbs et al., 2013), nonequilibrium ecologies resulting from accelerated climate change, the spread of invasive species, and anthropogenic land use.

It is in this context that rewilding is emerging as a hot topic in nature conservation. Rewilding shifts the focus of conservation from species composition to ecological processes and functions. It also moves the target baselines of conservation from premodern to prehistorical landscapes (for overviews and critical commentary see Lorimer et al., 2015; Svenning et al., 2016; Lorimer and Driessen, 2016). Interventions in the name of rewilding generally seek to (re)introduce ‘keystone species’: ‘species that play a disproportionately large role in the prevalence and population levels of other species within their ecosystem or community’ (Wagner, 2010: 51). Predators and large herbivores are deployed as ‘ecological engineers’ capable of instigating processes with desired landscape scale impacts. Continental scale schemes have been proposed to rewild Europe (Pereira and Navarro, 2015) and North America (Foreman, 2004).

Apex predators feature prominently in North American versions of rewilding, perhaps the most famous example being the reintroduction of wolves into Yellowstone National Park in the USA. The grey wolf (Canis lupis) was once one of the world’s most widely distributed mammals. But it was eradicated from Yellowstone (and most of North America and Europe) by the 1920s. Populations of herbivores like elk (Cervus elaphus) subsequently boomed and significant changes in vegetation were noted. This is a classic example of what biologists term a ‘trophic cascade’ (Terborgh and Estes, 2010), where the absence of an apex predator at the top of the food chain results in widespread and seemingly disproportionate ecological shifts.

Wolves were reintroduced to Yellowstone in 1995. This intervention sought to save a charismatic species, but it was also guided by a desire to intervene into the ecosystem to redress the past cascade. As wolf populations grew, those of elk reduced by over 50 per cent (Ripple and Beschta, 2004). There has been an increase in the new-growth of aspen and willow on the valley bottoms and in populations of beaver and bison. Biologists suggest these shifts relate in part to direct predation, but more significantly to changes in elk behaviour. Wolves create an ‘ecology of fear’ (Ripple and Beschta, 2004) in which they regulate the lower levels of the trophic pyramid: elk stop venturing into both deeper thickets and open areas, out of fear of being attacked. ¹

In Europe, rewilders are more concerned with the restoration of large herbivores and their grazing regimes. In one high-profile example, Dutch ecologists introduced ‘back-bred’ and ‘de-domesticated’ cattle and horses (along with deer) into the Oostvaardersplassen: an undeveloped polder landscape in the suburbs of Amsterdam. This experiment sought to reintroduce a ‘naturalistic grazing regime’ analogous to that performed by the aurochs and tarpan at the start of the Holocene (c. 10,000 BP) (Vera, 2009). The ecologists argued that, left to their own devices, these animals would create a ‘shifting mosaic’ of forest pasture landscapes, not the closed canopy forest that is currently held to be the natural ecology for the region (Vera, 2000). Populations of cattle and horses grew quickly at the Oostvaardersplassen and animals began dying of starvation. There were protests from animal welfare organizations and a compromise solution was arrived at in which the human ranger ‘becomes wolf’. Armed with a rifle and criteria for assessing (farm) animal welfare, he seeks to cull those animals that are judged not to be able to make it through the winter (Lorimer and Driessen, 2014). The site has been judged as too small for actual wolf reintroduction. In this ‘proactive predator simulation model’ the ranger performs the lethal agency of wolves. But it has not been possible to replicate the landscape scale ecology of fear that is believed to have reverted the trophic cascade at Yellowstone.

Reworming

Popular anxieties about declines and absences in the microbiome are more recent. During the 19th and 20th century microbes were generally cast as pathological ‘germs’ in need of eradication. Recent developments in the science and technology of metagenomics (the genetic sequencing of samples gathered from the wider environment) have helped map the abundance of microbial life associated with human bodies (Turnbaugh et al., 2007). Medical research increasingly points to the functional importance of the human microbiome. This work intersects with pre-existing hypotheses that link the rise of allergy, autoimmune and inflammatory disease to the excesses of hygiene and the demise of our ‘old friends’ (Rook and Brunet, 2005). Theorists suggest that the absence of microbial organisms with which we evolved unsettles basic bodily systems that enable metabolism, immunity and even cognition (Blaser and Falkow, 2009). The result is widespread dysbiosis (Logan et al., 2016). There is still a great deal of basic science to be done on the microbiome, and the discussion of translational applications is speculative and full of hype. Paxson and Helmreich note a general ‘microbiomania’ that has gripped the life sciences in which microbes figure as ‘tokens’ of an underdetermined biology ‘full of yet-to-be explored possibility’ (Paxson and Helmreich, 2014: 166). ²

Nonetheless, this thinking has informed a collection of scientific and other experiments in ‘biotherapy’ (Grassberger et al., 2013): the therapeutic use of nonhuman organisms to manage the ecologies of the human microbiome. These include ‘faecal transplants’ to shift antibiotic resistant bacteria (Spector and Knight, 2015) and ‘vaginal seeding’ to replicate birth canal bacterial colonization for babies born by Caesarean section (Dominguez-Bello et al., 2016). They encompass various pro- and pre-biotic diets designed to work on the gut microbiome, and novel personal and domestic hygiene products that actively seed the skin and built environment with stable colonies of ‘good bacteria’. ³

Human helminths have emerged as a prominent set of old friends. These animals are common to humans and have a long history of coevolution. Deworming has been central to programmes for global health and economic development (Ettling, 2013), as high wormloads have been linked to a range of health and productivity problems (Bethony et al., 2006). Human helminths have largely been eradicated (along with a host of other microbes) in the Global North, as a result of broader initiatives to control infectious disease. But they persist in large areas of the rural Global South, and helminth disease (helminthiasis) remains a global health problem (Hotez et al., 2008).

In the last 15 years several thousand generally affluent, urban and well-educated patients have begun reworming: using species like human hookworm (Necator americanus) therapeutically to tackle conditions such as hay fever, inflammatory bowel disease and even autism (Cheng et al., 2015). Studies in animal models and human clinical trials are underway (Wammes et al., 2014; Maizels, 2016), but these have been overtaken by a burgeoning ‘hookworm underground’ (Velasquez-Manoff, 2012). This online community links patients, researchers and advocates who share and sell animals, equipment and expertise.

Research suggests that some helminths can enter into symbiotic relationships with their human host. After an initial, generally unsuccessful, effort to shift the worms the body learns to tolerate a bearable wormload. Worms seem able to regulate and downgrade the host immune system to enable their persistence (Allen and Maizels, 2011). Microbiologists suggest that helminths can manipulate the microbial ecologies of their host for their own ends, in ways that might explain immune modulation (Versini et al., 2015). Some researchers envisage helminths as ‘keystone species’ (Bilbo et al., 2011), ‘talking’ to bacteria (Zaiss et al., 2015), and engaged in acts of ‘diplomacy’ (Steinfelder et al., 2016) with their hosts, who in turn now figure as ‘tolerating’ or even ‘actively recruiting’ microbes to maintain health (Gilbert et al., 2012).

In controlled political and ecological conditions some helminths have thus been recast as ‘gut buddies’ – salutary symbionts capable of recalibrating dysfunctional bodily relationships (Lorimer, 2016b). One provider of therapeutic helminths suggests that worms serve to ‘calibrate’ and then ‘exercise’ the immune system, keeping it sufficiently busy or distracted to avoid it turning against itself (Biome Restoration, 2016). Some advocates speak of the ‘rewilding’ of the human microbiome (Leach, 2015). They position these interventions as forms of ‘evolutionary medicine’ that detect and address ‘evolutionary mismatches’ between the ecological composition of human bodies and the external environments to which they are exposed (Parker and Ollerton, 2013). The science and the clinical trials that might make helminth therapy mainstream are still in their early stages. The field is subject to some of the hype associated with the microbiomania identified above. Many of those taking worms outside the trials recount transformations in their health and respite from conditions that are currently poorly managed even where patients have access to state-of-the-art immune-suppressant drug regimens (for a review see Liu et al., 2016).

Ecological Ontologies

Although they range across scales and knowledge and policy domains, these interventions share four components of a common ontology. The first is an ecological conception of life. This is concerned more with the processes of movement, circulation and interaction than with the essential character and composition of its constituent forms. Nonhuman species are secondary to the functions and services they deliver through their systemic effects. To differing degrees, wolves, cows and worms are valued for their ecological roles, rather than their rarity, authenticity, or charisma in interspecies encounters. Humans and other animals are folded into (and even become) ecological ‘milieux’ (after Foucault, 2007: 20–21). This is an entangled ontology of ‘multispecies becomings with’ (Haraway, 2008). Diverse relations are targeted in these interventions. They span the epigenetic and symbiotic molecular interactions through which hookworms deliver immunity, the selective grazing preferences of herbivores that are shaped and communicated by plants, and the ecologies of fear (and calm or even boredom) configured by predator presence and absence.

Second, these ecologies are nonequilibrium. There is no timeless balance of nature in these examples. Instead, these ecologies involve ‘interaction webs’ (Estes et al., 2011: 13) that are marked by relations of differing intensities. These webs are spaced through extensive connections and are understood to be ‘metastable’: capable of moving between, and conforming to, alternative stable states (Eisenberg, 2010). Examples might include a shift from a forest to a savannah landscape, or the emergence of an inflammatory disease like Crohn’s. The passage between these states is marked by ‘thresholds’ and ‘tipping points’ (Groffman et al., 2006). In the cases of rewilding and reworming, these changes in state are associated with local species extinctions. These ecologies show hysteresis, in that they do not necessarily move equally easily into and out of different states as a result of the return of absences. There is a great deal of contingency and complexity within these webs, which are animated by ‘discordant harmonies’ (Botkin, 1990).

In some ways this ontology is akin to that identified in recent critical writings on environmental and biological security (Braun, 2014; Massumi, 2009; Hinchliffe et al., 2013). Massumi notes how ‘the figure of the environment shifts: from the harmony of a natural balance to a churning seed-bed of crisis in the perpetual making’ (2009: 154). What is different in the specific relations examined here is the significance of absences (rather than excessive presences) as the cause of environmental pathologies. It is the absence of ecological components that causes problems, unlike the anticipated security crises that stem from an overly energized global climate, or the biosecurity risks of emerging infectious diseases in intensive and globalized agriculture. Ecologies subject to rewilding and reworming are already tipped into disaster and in need of proactive transformation.

A common absence provides the third connecting component in this ontology. This is captured by the figure of the keystone species. These ‘strongly interactive’ (Soulé et al., 2005) animals control the dynamics of an ecosystem. Ecologists and immunologists first became aware of the pathological absences of wolves and worms through detections of their ‘ghostly’ presence in dysfunctional relations. In nature reserves, the absence of species that would have performed functions like predation, pollination, dispersal and germination is understood to generate ‘anachronisms’: species and ecologies with rhythms ill attuned to their contemporary context (for a discussion see Barlow, 2000). Similar thinking informs the microbiologists and immunologists who link the autoimmune effects of missing microbes to ‘evolutionary mismatches’ between the host and their absent symbionts (Parker and Ollerton, 2013). They suggest that the absence of the calibrating agencies of keystone species makes the system go awry and causes dysbiosis. In this holistic formulation parts of a once functional ecology are seen to turn against the wider ‘self’– be it the human superorganism or the nature reserve. The ecology in question subsequently changes state, becoming inflamed, autoimmune or lacking in resilience.

Fourth, these interventions remain centred on securing valued versions of human life. But they recognize this to be fundamentally entangled with the nonhuman world in all its biological, geological and technological diversity. Rewilding and reworming share a more-than-human ontology that links the planetary to the microscopic. On the macro scale, rewilding is being shaped by discourses around the Anthropocene: that (some) humans have become a geological force, shaping the evolutionary conditions for future planetary wilds. Multiple future natures are possible, and these will emerge in conditions far from the purified wilderness. Similarly, the figure of the human as a degraded superorganism flags the ontological significance of the non-us in us. Being human is presented as a multispecies achievement (Haraway, 2016). Mobile microbes link us with each other, our domestic animals and the wider environment. The human is folded into a micro-ontology (Hird, 2009) of porous bodies and lateral exchange. This ontostory radically redistributes agency. It recognizes both the risks and the ‘corporeal generosity’ (Diprose, 2002) of the microbes that shape our thoughts, feelings and sociabilities.

A Probiotic Environmentality

Work on biosecurity (e.g. Massumi, 2009; Braun, 2014) connects this ecological ontology to a mutation in late modern modes of government, first detected by Michel Foucault in the 1970s. Foucault (2010) briefly identifies the emergence of ‘environmentalities’, or forms of an ‘environmental’ mode of biopower, in his lectures on neoliberalism and government in conditions of crisis. Subsequent commentators have developed this concept in ways that are helpful for understanding the modes of government associated with the probiotic turn.

We can contrast environmentalities with sovereign and disciplinary power – whose focus is on the human body or subjectivity – and regimes of biopolitics, concerned with governing life at the scale of the population. ⁴ Instead, Anderson explains that ‘environmentalities work through systematic modifications of the “environment” within which an action occurs, rather than directly on the body’s capabilities’ (Anderson, 2012: 39). He suggests that ‘an environmentality is a logic that functions on a far-from-equilibrium environment by modulating the aleatory (chance or random) human and non-human processes that make up that environment’ (Anderson, 2011: 232). Wakefield and Braun note that this mode of government involves ‘not just the government of integrated and highly technologized socioecological systems, but government through such systems, such that it is no longer clear that government in any way seeks to produce subjects as it did before. Government, from this view, is as much about managing circulation and modulating flows as it is about molding individuals’ (Wakefield and Braun, 2014: 5).

Writing about the environmentality of probiotic forms of urban flood management, Braun identifies a ‘decidedly fluid and flexible landscape’ of biopower in which ‘things are permitted to “flow” and natural processes are allowed to “function”, such that nature’s diversity provides the “service” of cancelling out the very risks that nature itself presents in an age of anthropogenic climate change. One does not work against nature, as with modernist design concepts; rather, one works with it’ (2014: 58–9). He suggests that this account:

reverses a common story about ‘sustainable’ or ‘resilient’ urbanism that assumes that what we are witnessing today is a long-overdue adaptation of urban life to the unpredictable rhythms of the ecological world … rather, it is that governing through the naturalness of nature at the scale of the city must be understood as a particular mode of government, one that may be less of a departure from already existing modes than an extension of a particular apparatus in which molding life is replaced by modulating natural processes, now extended to include the nonhuman world itself. (2014: 60)

The concept of environmental biopower resonates more with discussions of the ‘microbiopolitics’ (Paxson, 2008) or ‘symbiopolitics’ (Helmreich, 2009) of governing microbial relations. Paxson (2008) has examined probiotic forms of microbiopolitics in her work on the human-microbial relationships associated with the raw milk cheese movement in the USA. She describes these as ‘post-Pasteurian’ (rather than anti-Pasteurian). Paxson explains that ‘post-Pasteurianism takes after Pasteurianism in taking hygiene seriously. It differs in being more discriminating’ (2014: 118). Her analysis is echoed in writings by Keulartz (2012) on rewilding and probiotic forms of flood management in the Netherlands. Keulartz argues that these involve the ‘controlled decontrolling of ecological controls’ (2012: 16) to enable landscape scale interventions that shift the ecological and biophysical intensities within which nonhuman actors come into being.

Rewilding and reworming can be understood to involve environmental forms of biopower that depart in interesting ways from those reported in the limited literature on biosecurity (reviewed above). The primary ‘environmental’ political technology deployed is the strategic use of keystone species. While wolves and cows (and to a much lesser extent) worms are disciplined as individuals and governed as species (biopolitics), those concerned with their reintroduction are primarily interested in their ecological or ‘environmental’ agencies. As ‘ecological engineers’ and ‘gut buddies’ they are valued for their abilities to modulate or recalibrate dysfunctional ecologies. They enable human ‘rewilders’ to attempt ecosystem-level change to redress ‘trophic cascades’ or ‘evolutionary mismatches’. The hope is that the target ecosystem has limited hysteresis and can be tipped (back) over a threshold towards one in which the rhythms of its constituent circulations can be synchronized to deliver desired functionality. Worms and wolves are introduced to modulate the specific milieux of the human body or the nature reserve by shifting ecological intensities and channelling flows to secure desired circulations.

While the ‘antibiotic’ practices of modern hygiene and wildlife conservation seek to head off a change in phase state to preserve homeostasis and equilibrium, probiotic environmentalities seek to initiate transformative events. The aim is to work with and modulate the emergent properties of interspecies interaction webs to reconfigure the basic conditions in which life persists. Probiotic environmentalities seek thresholds and try to tip systems across them. On the one hand, these interventions are akin to practices of (bio)security, which in Anderson’s terms ‘act in relation to the contingencies of life by attempting to seize possession of the future before it occurs and shaping how contingent decisions or events will unfold’ (2012: 39). Where they differ is in relation to the temporality of the crisis to which they respond. While forms of biosecurity seek to manage circulations to build resilience in the face of imminent but unavoidable disaster, probiotic approaches figure the present as already disastrous. They seek to reverse, restore or otherwise address deleterious existing transitions.

Transformative Environmentalities?

This reading opens up environmentalities that challenge the status quo. Existing work has tended to align the prevalent practices of biosecurity and the biopolitics of resilience with the logics of neoliberalism, anthropocentrism and neocolonialism. In the final section of this analysis I will begin to explore the critical potential of the probiotic turn, examining the ways in which the deliberate pursuit of tipping points can both sustain and transform political and ecological relations. There are many different axes along which one might look to specify the probiotic turn. Here I will focus first on questions of political economy, before turning to questions of anthropocentrism and human-nonhuman relations.

Conclusions: Hospitality in the Anthropocene

This article has identified and illustrated a probiotic turn in late modern modes of government. This turn seeks to address the ‘pathologies’ associated with antibiotic ways of managing life by (re)introducing keystone species to reorganize a range of dysfunctional political ecologies. These interventions shift the intensities of these ecologies and aim to tip them towards a desired future state. Here the generative and disruptive potential of ‘wildness’ has been revaluated. The wild shifts from being ‘the monster at the door’ (Davis, 2005) to a generative potential for creating desired ‘post-Pasteurian’ ecologies. The probiotic turn has been situated within the broader emergence of environmental modes of biopower in the 21st century. Probiotic environmentalities differ from the environmentalities of biosecurity in their proactive identification of tipping points. A brief review of the political economy and human-nonhuman relations performed in the probiotic turn reveals its potential to both sustain and transform prevalent forms of governance.

I will conclude by positioning this argument more explicitly in the context of ongoing debates around hospitality and politics in the Anthropocene. The current intellectual fervour associated with the Anthropocene (Lorimer, 2016a) has distilled and amplified deep rifts in late modern biopolitical thought. The popular realization that humans are inextricably folded into the Earth foregrounds the degree to which biopower becomes unavoidably ‘environmental’. Any deliberate or inadvertent environmental intervention, from the bodily to the planetary scale, has the potential to configure the conditions under which life exists. Anthropocenic interventions configure which subjects and populations are made to live and let die. There can be no return to Nature, or retreat to bodily purity. Instead, social and interspecies hospitality requires attention, and intervention is unavoidable. The epochal proclamation of the Anthropocene represents a provocation. For some, it is a challenge to assume our Enlightenment destiny as the ‘God Species’ (Lynas, 2011). We can imagine a ‘good Anthropocene’ (Asafu-Adjaye et al., 2015) in which we design and implement grand schemes for planetary management. For critics, like Donna Haraway (2015), the name represents an ‘extraordinary contradiction’, ⁶ and a neocolonial, capitalist and patriarchal imposition at a time when human exceptionalism should be on the wane as political, conceptual and methodological categories.

In this spirit I would suggest that there is transformative potential in some dimensions of the probiotic turn for imagining and enacting more-than-human forms of hospitality in the Anthropocene. These practices help overcome the impasse identified by Cary Wolfe in existing approaches to environmental politics. These, he argues, are premised on either elevating animals (including humans) to the essential status of ‘the person’, or on dissolving animal subjects into a ‘radically dedifferentiating discourse of “life”’ (2012: 58). The former effaces animal difference, while the latter (which he finds most clearly expressed in the writings of Robert Esposito) provides no grounds from which one can extend hospitality. Instead, he argues that hospitality is not unconditional, but it involves working through encounters, and with nonlinear ecological processes, to permit various forms of flourishing (after Haraway, 2008). Wolfe’s argument resonates with recent work on hospitality in multispecies studies that seeks to ground Derrida’s ‘abstract’ (Candea, 2012) conception of unconditional hospitality in the specific materialities of human and nonhuman relations (see Van Dooren, 2016).

Thinking relationally with wolves and worms helps us grapple with the materialities and specificities of Anthropocene hospitality. Reworming and rewilding start from a basic ‘immunitary’ impulse to protect individual and aggregate forms of life. These include human bodies and charismatic species. But life is conceived as a field of ecological difference that can be made subject to forms of environmental biopower. In an environmental formulation immunity requires a communitarian (Esposito, 2011) form involving tolerance, accommodation or even the active recruitment of microbial mutualists. But these forms of companionship happen alongside more martial practices of control or even eradication. Probiotic relations with wolves and worms confirm that pathogens exist, but show that their form is not essential (see Kelly, 2012). Instead, pathologies emerge out of particular political-ecological ‘configurations’ (Hinchliffe et al., 2016) in which both absence and excessive presence can cause problems. Hospitality thus becomes an ecological affair, performed through the choreography of ‘polyphonic’ (after Tsing, 2015) and discordant spatio-temporal rhythms.

Situating deliberate re-entanglements like rewilding and reworming in their specific spatio-temporal configurations shows that we cannot analyse the probiotic turn outside of the violent colonial presents, and forms of political economy, within which it proceeds. There are spatial ‘pathologies of power’ (Farmer, 2004) that shape who is abandoned to neglected tropical and emergent non-communicable diseases, and who will benefit from emerging forms of helminthic therapy. Comparable pathologies shape which land is abandoned and expropriated to make space for rewilded ecologies. Yet rewilding does offer grounds for hope. Communal platforms for the exchange of worms, or the resurgence of wildlife in the (sub)urban ecologies of post-industrial cities, present unruly political ecologies and probiotic ‘arts of living’ (Tsing, 2015). The probiotic turn offers tentative means for imagining the Anthropocene as a ‘boundary condition’ (see Haraway, 2015): a key juncture in the transition towards a more hospitable epoch.