Healthism and ableism intertwine through an imperative of normalcy and the ensuing devaluing of those who fail to meet societally dominant norms and expectations around “normal” health. This paper tracks the effect of that imperative of normalcy through current research into gut microbiome therapies, using therapies targeting fatness and autism as examples. The complexity of the gut microbiome ought to encourage us to rethink our conception of ourselves and our embeddedness in the world; instead, the microbiome is (...) transformed into one more tool for controlling unruly bodies and minds. (shrink)

We propose that hyper‐inflammation (HYPi) is a ‘‘runaway’’ consequence of acute inflammation (ACUi) that arises more easily (and also abates less easily) in those who host a pre‐existing chronic inflammation (CHRi), because (i) most factors involved in generating an ACUi to limit viral proliferation are already present when there is an underlying CHRi, and also because (ii) anti‐inflammatory (AI) mechanisms for the abatement of ACUi (following containment of viral proliferation) are suppressed and desensitized where there is an underlying CHRi, with (...) this causing the ACUi to spiral into a HYPi. Stress, pollution, diet, and gut microbiomes (alterable in weeks through dietary changes) have an intimate and bidirectional cause‐effect relationship with CHRi. We propose that avoidance of CHRi‐promoting foods and adoption of CHRi‐suppressing foods could reduce susceptibility to HYPi, in Covid‐19 and in other viral diseases, such as influenza, which are characterized by episodic and unpredictable HYPi. (shrink)

The microbiota-gut-brain axis field is at an exciting stage, but the most recent developments in microbiota research still have to find their way into MGB studies. Here we outline the standards for microbiome data generation, the appropriate statistical techniques, and the covariates that should be included in MGB studies to optimize discovery and translation to clinical applications.

Graphical AbstractMicrobiome research attributes to whole microbiomes a causal role in the occurrence of different health outcomes. I argue, following some distinctions about causal relationships and explanations made within a philosophical account of causation, the “interventionist account,” that such claims need more scrutiny.

I examine the feminist epistemic values in science, presented by Helen Longino, and their role in framing microbiome causality in the study of inflammatory bowel disease (IBD). In particular, I show how values presented as feminist give an alternative view in scientific theories—focusing on ontological heterogeneity and mutuality of interactions rather than simplicity and one causal direction—when looking at relations between organisms and microorganisms, and between organisms (particularly humans) and their environment. I identify two approaches in microbiome study, (...) an immunological approach that looks at the microbiome pathogenicity and an ecological approach that studies the microbial activity and functions. I show the puzzles stemming from the traditional background beliefs of the immune self and germ theory in the study of IBD causality. Furthermore, I argue for the benefits of a shift to the ecological view of body-microbe interrelations. I conclude with the benefits and advantages of feminist values over traditional ones, both in creating new ways of understanding organisms’ physiology and immune systems and for future biomedical studies involving microbiome causality. (shrink)

Graphical AbstractIdentifying the properties and molecules of the intestinal microbiome may help our understanding of various diseases and therefore facilitate their treatment; from excluding pathogens to manipulation of the immune system and regulation of non-intestinal sites.

The complexity of the human mind and its interaction with the environment is one of the main epistemological debates throughout history. Recent ideas, framed as the 4E perspective to cognition, highlight that human experience depends causally on both cerebral and extracranial processes, but also is embedded in a particular sociomaterial context and is a product of historical accumulation of trajectory changes throughout life. Accordingly, the human microbiome is one of the most intriguing actors modulating brain function and physiology. Here, (...) we present the 4E approach to the Human Microbiome for understanding mental processes from a broader perspective, encompassing one's body physiology and environment throughout their lifespan, interconnected by microbiome community structure and dynamics. We review evidence supporting the approach theoretically and motivates the study of the global set of microbial ecosystem networks encountered by a person across their lifetime (from skin to gut to natural and built environments). We furthermore trace future empirical implementation of the approach. We finally discuss novel research opportunities and clinical interventions aimed toward developing low‐cost/high‐benefit integrative and personalized bio‐psycho‐socio‐environmental treatments for mental health and including the brain‐gut‐microbiome axis. (shrink)

Therapeutic translations of the microbiome-gut-brain (MGB) axis are reconstructing the educational subject in a manner amenable to Foucauldian analysis. Yet, at the same time, under the sway of MGB research social scientists are taking a biosocial turn that threatens the integrity of Foucault’s historicizing philosophical project. Meeting that challenge head-on, this article argues that the MGB axis augments the neurobiological constitution of the educational subject by means of a dietetic mode of subjectivation. Absent a pedagogical element, there is a (...) hollowness to critical academics’ claims that holobiontic self-conceptions springing from the axis can elicit a resistant subjectivity. Though wild pedagogies might inform a resistant tactics of the self, contemporary self-technologies are – as Foucault has taught us – a pale shadow of the ancient Greek conception of dietetics as an holistic, embodied and ensouled practice. At the intersection between the disciplinary apparatuses of criminology and education, therefore, the MGB-driven biosocial turn unambiguously reinforces the social control function of schooling. (shrink)

Much microbiota-gut-brain research focuses on the causal role of microbiomes as a whole, rather than their component parts: microbes. Hooks et al. find these whole-community explanations inadequate; however, they do not provide suggestions for better explanations. By appealing to proportionality – a criterion that can be used to develop more appropriate causal explanations – more accurate causal claims can be made.

There has been a spurt in both fundamental and translational research that examines the underlying mechanisms of the human microbiome in psychiatric disorders. The personalized and dynamic features of the human microbiome suggest the potential of its manipulation for precision psychiatry in ways to improve mental health and avoid disease. However, findings in the field of microbiome also raise philosophical and ethical questions. From a philosophical point of view, they may yet be another attempt at providing a (...) biological cause for phenomena that ultimately cannot be so easily localized. From an ethical point of view, it is relevant that the human gut microbiome comprises data on the individual’s lifestyle, disease history, previous medications, and mental health. Massive datasets of microbiome sequences are collected to facilitate comparative studies to identify specific links between the microbiome and mental health. Although this emerging research domain may show promise for psychiatric patients, it is surrounded by ethical challenges regarding patient privacy, health risks, effects on personal identity, and concerns about responsibility. This narrative overview displays the roles and advances of microbiome research in psychiatry and discusses the philosophical and ethical implications of microbiome big data and microbiome-based interventions for psychiatric patients. We also investigate whether these issues are really “new,” or “old wine in new bottles.”. (shrink)

Does exploration of the gut microbiota–brain axis expand our understanding of what it means to be human? Recognition and conceptualization of a gut microbiota–brain axis challenges our study of the nervous system. Here, integrating gut microbiota–brain research into the metaorganism model is proposed. The metaorganism—an expanded, dynamic unit comprising the host and commensal organisms—asserts a radical blurring between man and microbe. The metaorganism nervous system interacts with the exterior world through microbial‐colored lenses. Ongoing studies have reported that gut microbes contribute (...) to brain function and pathologies, even shaping higher neurological functions. How will continued collaborative efforts (e.g., between neurobiology and microbiology), including partnerships with the arts (e.g., philosophy), contribute to the knowledge of microbe‐to‐mind interactions? While this is not a systemic review, this nascent field is briefly described, highlighting ongoing challenges and recommendations for emerging gut microbiota–brain research. Also see the video abstract here https://youtu.be/lP9gOW8StXg. (shrink)

All organisms live in close association with microbes. However, not all such associations are meaningful in an evolutionary context. Current debate concerns whether hosts and microbes are best described as communities of individuals or as holobionts (selective units of hosts plus their microbes). Recent reports that assortative mating of hosts by diet can be mediated by commensal gut microbes have attracted interest as a potential route to host reproductive isolation (RI). Here, the authors discuss logical problems with this line of (...) argument. The authors briefly review how microbes can affect host mating preferences and evaluate recent findings from fruitflies. Endosymbionts can potentially influence host RI given stable and recurrent co‐association of hosts and microbes over evolutionary time. However, observations of co‐occurrence of microbes and hosts are ripe for misinterpretation and such associations will rarely represent a meaningful holobiont. A framework in which hosts and their microbes are independent evolutionary units provides the only satisfactory explanation for the observed range of effects and associations. (shrink)

The concept that alterated communications between the gut microbiome and the brain may play an important role in human brain disorders has recently received considerable attention. This is the result of provocative preclinical and some clinical evidence supporting early hypotheses about such communication in health and disease. Gastrointestinal symptoms are a common comorbidity in patients with autism spectrum disorders (ASD), even though the underlying mechanisms are largely unknown. In addition, alteration in the composition and metabolic products of the gut (...) microbiome has long been implicated as a possible causative mechanism contributing to ASD pathophysiology, and this hypothesis has been supported by several recently published evidence from rodent models of autism induced by prenatal insults to the mother. Recent evidence in one such model involving maternal infection, that is characterized by alterations in behavior, gut physiology, microbial composition, and related metabolite profile, suggests a possible benefit of probiotic treatment on several of the observed abnormal behaviors. (shrink)

Gut microbiome plays a significant role in defining the health status of subjects, and recent studies highlight the importance of using time series strategies to analyse microbiome dynamics. In this paper, we develop a Bayesian model for microbiota longitudinal data, based on Dirichlet distribution with time-varying parameters, that take into account the compositional paradigm and consider principal balances. The proposed model can be effective for predicting the future dynamics of a microbial community in the short term and for (...) analysing the microbial interactions using the value of the estimated parameters. The usefulness of the proposed model is illustrated with six different datasets, and a comparison study with four alternative models is provided. (shrink)

As it becomes increasingly plausible that the mind–brain is explicable in naturalistic terms, science‐and‐religion scholars have the opportunity to engage creatively and proactively with facets of brain‐related research that better inform our understanding of human well‐being. That is, once mental health is recognized as being a whole‐body phenomenon, exciting theological conversations can take place. One fascinating area of research involves the “gut–brain axis,” or the interactive relationship between the microbiome in the gastrointestinal tract (i.e., gut bacteria), the central nervous (...) system, and mental health. A growing body of literature explores the immensely significant interactions between the gut microbiome and mental health issues involving depression, anxiety, gene expression, and stress responses. One's mental health does not occur in a disembodied state, but in a complex physical environment that is strongly influenced by environmental factors, many of which we can control. This article argues that science‐and‐religion can welcome scientific research in this area, creatively incorporating such insights into a theology of mental health and physical well‐being. (shrink)

Humans’ indigenous microbes strongly influence organ functions in an age‐ and diet‐dependent manner, adding an important dimension to aging biology that remains poorly understood. Although age‐related differences in the gut microbiota composition correlate with age‐related loss of organ function and diseases, including inflammation and frailty, variation exists among the elderly, especially centenarians and people living in areas of extreme longevity. Studies using short‐lived as well as nonsenescent model organisms provide surprising functional insights into factors affecting aging and implicate attenuating effects (...) of microbes as well as a crucial role for certain transcription factors like forkhead box O. The unexpected beneficial effects of microbes on aged animals imply an even more complex interplay between the gut microbiome and the host. The microbiome constitutes the major interface between humans and the environment, is influenced by biosocial stressors and behaviors, and mediates effects on health and aging processes, while being moderated by sex and developmental stages. (shrink)

It is becoming increasingly clear that most, if not all, animals and plants are associated with a diverse array of resident gut microbiota. This symbiosis is regulated by host-microbiome interactions which influence the development, homeostasis, adaptation and evolution of the host. Recent evidence indicated that these interactions can also affect the host germline and have a potential of supporting transgenerational effects, including inheritance of acquired characteristics. Taken together, the influence of gut bacteria on the host soma and germline could (...) potentially give rise to emergent phenotypes, which may be partially inherited by three distinguishable modes of transgenerational influence of gut bacteria: 1) “soma-to-soma” 2) “soma-to-germline” and 3) “soma-germline-soma”. Here, we discuss these possibilities in light of evidence supporting bacterial-mediated modes of transgenerational inheritance. All animals are consortiums of hosts and microbiota. Their interactions influence many aspects of the adaptation and evolution of the Holobiont. The host germline can also be affected which can give rise to new modes of transgenerational influence of gut bacteria: 1) “soma-to-soma” 2) “soma-to-germline,” and 3) “soma-germline-soma.”. (shrink)

Human evolution has been punctuated by climate anomalies, structuring environments, deadly infections, and altering landscapes. How well humans adapted to these new circumstances had direct effects on fitness and survival. Here, how the gut microbiome could have contributed to human evolutionary success through contributions to host nutritional buffering and infectious disease resistance is reviewed. How changes in human genetics, diet, disease exposure, and social environments almost certainly altered microbial community composition is also explored. Emerging research points to the (...) class='Hi'>microbiome as a key player in host responses to environmental change. Therefore, the reciprocal interactions between humans and their microbes are likely to have shaped human patterns of local adaptation throughout our shared evolutionary history. Recent alterations in human lifestyle, however, are altering human microbiomes in unprecedented ways. The consequences of interrupted host–microbe relationships for human adaptive potential in the future are unknown. (shrink)

The human intestinal ecosystem, previously called the gut microflora is now known as the Human Gut Microbiota. Microbiome research has emphasized the potential role of this ecosystem in human homeostasis, offering unexpected opportunities in therapeutics, far beyond digestive diseases. It has also highlighted ethical, social and commercial concerns related to the gut microbiota. As diet factors are accepted to be the major regulator of the gut microbiota, the modulation of its composition, either by antibiotics or by food intake, should (...) be regarded as a fascinating tool for improving the human health. Scientists, the food industry, consumers and policymakers alike are involved in this new field of nutrition. Defining how knowledge about the HGM is being translated into public perception has never been addressed before. This raises the question of metaphors associated with the HGM, and how they could be used to improve public understanding, and to influence individual decision-making on healthcare policy. This article suggests that a meeting of stakeholders from the social sciences, basic research and the food industry, taking an epistemological approach to the HGM, is needed to foster close, innovative partnerships that will help shape public perception and enable novel behavioural interventions that would benefit public health. (shrink)

We show how metagenomic analysis of the human gut antibiotic resistome, compared across large populations and against environmental or agricultural resistomes, suggests a strong anthropogenic cause behind increasing antibiotic resistance in bacteria. This area has been the subject of intense and polarized debate driven by economic and political concerns; therefore such recently available insights address an important need. We derive and compare antibiotic resistomes of human gut microbes from 832 individuals from ten different countries. We observe and describe significant differences (...) between samples from these countries in the gut resistance potential, in line with expectations from antibiotic usage and exposure in medical and food production contexts. Our results imply roles for both of these sources in increased resistance among pathogens in recent history. In contrast, other available metadata such as age, body mass index, sex, or health status have little effect on the antibiotic resistance potential of human gut microbes.Also watch the Video Abstract. (shrink)

Transfer RNA (tRNA) modifications play an important role in regulating mRNA translation at the codon level. tRNA modifications can influence codon selection and optimality, thus shifting translation toward specific sets of mRNAs in a dynamic manner. Queuosine (Q) is a tRNA modification occurring at the wobble position. In eukaryotes, queuosine is synthesized by the tRNA‐guanine trans‐glycosylase (TGT) complex, which incorporates the nucleobase queuine (or Qbase) into guanine of the GUN anticodons. Queuine is sourced from gut bacteria and dietary intake. Q (...) was recently shown to be critical for cellular responses to oxidative and mitochondrial stresses, as well as its potential role in neurodegenerative diseases and brain health. These unique features of Q provide an interesting insight into the regulation of mRNA translation by gut bacteria, and the potential health implications. In this review, Q biology is examined in the light of recent literature and nearly 4 decades of research. Q's role in neuropsychiatric diseases and cancer is highlighted and discussed. Given the recent interest in Q, and the new findings, more research is needed to fully comprehend its biological function and disease relevance, especially in neurobiology. (shrink)

Emphatic claims of a “microbiome revolution” aside, the study of the gut microbiota and its role in organismal development and evolution is a central feature of so-called postgenomics; namely, a conceptual and/or practical turn in contemporary life sciences, which departs from genetic determinism and reductionism to explore holism, emergentism and complexity in biological knowledge-production. This paper analyses the making of postgenomic knowledge about developmental symbiosis in Drosophila melanogaster by a specific group of microbiome scientists. Drawing from both practical (...) philosophy of science and Science and Technology Studies, the paper documents epistemological questions of artefactuality and representativeness of model organisms as they emerge in the day-to-day labour producing and being produced by the “microbiome revolution." Specifically, the paper builds on all the written and editorial exchanges involved in the troubled publication of a research paper studying the symbiotic role of the microbiota in the flies’ development. These written materials permit us to delimit the network of justifications, evidence, standards of knowledge-production, trust in the tools and research designs that make up the conditions of possibility of a postgenomic fact. More than reframing the organism as a radically novel multiplicity of reactive genomes, we conclude, doing postgenomic research on the microbiota and symbiosis means producing a story that deviates from the scripts embedded into the sociotechnical experimental systems of post-Human Genome Project life sciences. (shrink)

How much bacterial evolution occurs in our intestines and which factors control it are currently burning questions. The formation of new ecotypes, some of which capable of coexisting for long periods of time, is highly likely in our guts. Horizontal gene transfer driven by temperate phages that can perform lysogeny is also widespread in mammalian intestines. Yet, the roles of mutation and especially lysogeny as key drivers of gut bacterial adaptation remain poorly understood. The mammalian gut contains hundreds of bacterial (...) species, each with many strains and ecotypes, whose abundance varies along the lifetime of a host. A continuous high input of mutations and horizontal gene transfer events mediated by temperate phages drives that diversity. Future experiments to study the interaction between mutations that cause adaptation in microbiomes and lysogenic events with different costs and benefits will be key to understand the dynamic microbiomes of mammals. Also see the video abstract here: https://youtu.be/Zjqsiyb5Pk0. (shrink)

Dietary fiber and prebiotics consistently modulate microbiota composition and function and hence may constitute a powerful tool in microbiota-gut-brain axis research. However, this is largely ignored in Hooks et al.’s analysis, which highlights the limitations of probiotics in establishing microbiome-mediated effects on neurobehavioral functioning and neglects discussing the potential of prebiotics in warranting the microbiota's role in such effects.

This article reformulates Stephan Helmreich´s the ¨microbiomisation of race¨ as the historiality of otherness in the foundations of human microbiome science. Through the lens of my ethnographic fieldwork of a transnational community of microbiome scientists that conducted a landmark human microbiome research on indigenous microbes and its affiliated and first personalised microbiome initiative, the American Gut Project, I follow and trace the key actors, experimental systems and onto-epistemic claims in the emergence of human microbiome science (...) a decade ago. In doing so, I show the links between the reinscription of race, comparative research on the microbial genetic variation of human populations and the remining of bioprospected data for personalised medicine. In these unpredictable research movements, the microbiome of non-Western peoples and territories is much more than a side project or a specific approach within the field: it constitutes the nucleus of its experimental system, opening towards subsequent and cumulative research processes and knowledge production in human microbiome science. The article demonstrates that while human microbiome science is articulated upon the microbial ‘makeup’ of non-wester(nised) communities, societies, and locales, its results and therapeutics are only applicable to medical conditions affecting rich nations (i.e., inflammatory, autoimmune, and metabolic diseases). My reformulation of ¨microbiomisation of race¨ as the condition of possibility of human microbiome science reveals that its individual dimension is sustained by microbial DNA data from human populations through bioprospecting practices and gains meaning through personalised medicine initiatives, informal online networks of pseudoscientific and commodified microbial-related evidence. (shrink)

We identify the significance and typical requirements of developmental analyses of the microbiome-gut-brain in parents, offspring, and parent-offspring relations, which have particular importance for neurobehavioral outcomes in mammalian species, including humans. We call for a focus on behavioral measures of social-emotional function. Methodological approaches to interpreting relations between the microbiota and behavior are discussed.

We argue for the importance of looking at the microbiota-gut-brain axis from a human developmental perspective. For this purpose, we first briefly highlight emerging research with infants attesting that the microbiome plays a role in early brain and cognitive development. We then discuss the use of developmentally informed humanized mouse models and implications of microbiome research that go beyond probiotic administration.

It is necessary to complement next‐generation sequencing data on the soil resistome with theoretical knowledge provided by ecological studies regarding the spread of antibiotic resistant bacteria (ARB) in the abiotic and, especially, biotic fraction of the soil ecosystem. Particularly, when ARB enter agricultural soils as a consequence of the application of animal manure as fertilizer, from a microbial ecology perspective, it is important to know their fate along the soil food web, that is, throughout that complex network of feeding interactions (...) among members of the soil biota that has crucial effects on species richness and ecosystem productivity and stability. It is critical to study how the ARB that enter the soil through the application of manure can reach other taxonomical groups (e.g., fungi, protists, nematodes, arthropods, earthworms), paying special attention to their presence in the gut microbiomes of mesofauna‐macrofauna and to the possibilities for horizontal gene transfer of antibiotic resistant genes. (shrink)

The Hooks et al. review of microbiota-gut-brain literature provides a constructive criticism of the general approaches encompassing MGB research. This commentary extends their review by: highlighting capabilities of advanced systems-biology “-omics” techniques for microbiome research and recommending that combining these high-resolution techniques with intervention-based experimental design may be the path forward for future MGB research.

Our analysis of microbiota-gut-brain research took MGB to task for some of its methods, concepts, and interpretations. Commentators then raised numerous issues about the neuroscientific and microbiome aspects of MGB and how it can be understood as a field. We respond by addressing the dimensionality and causal focus of MGB.

The target article suggests inter-individual variability is a weakness of microbiota-gut-brain research, but we discuss why it is actually a strength. We comment on how accounting for individual differences can help researchers systematically understand the observed variance in microbiota composition, interpret null findings, and potentially improve the efficacy of therapeutic treatments in future clinical microbiome research.

Here we argue that a multidisciplinary research approach, such as currently practised in the field of developmental cognitive neuroscience, is key to maintaining current momentum and to future-proof the field of microbiome-gut-brain research. Moreover, such a comprehensive approach will also bring us closer to our aims of translation and targeted intervention approaches to improve mental health and well-being.

Alterations in the gut microbiome have increasingly been implicated in driving obesity and its associated diseases, but underlying mechanisms remain poorly defined. Herein, in addition to reviewing the field, we hypothesize that a highly significant causative factor of such inflammatory disease‐associated microbiome alterations is a more aggressive microbiota that encroaches upon its host, with components having high potential to activate host pro‐inflammatory gene expression in a manner that drives metabolic disease. We further hypothesize that a range of societal (...) changes, including use of antibiotics and increasing consumption of food additives, have provoked such microbiota aggression and, consequently, may be contributing factors to the increased incidence of obesity and its associated diseases. (shrink)

Decaying wood, while an abundant and stable resource, presents considerable nutritional challenges due to its structural rigidity, chemical recalcitrance, and low nitrogen content. Despite these challenges, certain insect lineages have successfully evolved saproxylophagy (consuming and deriving sustenance from decaying wood), impacting nutrient recycling in ecosystems and carbon sequestration dynamics. This study explores the uneven phylogenetic distribution of saproxylophagy across insects and delves into the evolutionary origins of this trait in disparate insect orders. Employing a comprehensive analysis of gut microbiome (...) data, from both saproxylophagous insects and their non‐saproxylophagous relatives, including new data from unexplored wood‐feeding insects, this Hypothesis paper discusses the broader phylogenetic context and potential adaptations necessary for this dietary specialization. The study proposes the “Detritivore‐First Hypothesis,” suggesting an evolutionary pathway to saproxylophagy through detritivory, and highlights the critical role of symbiotic gut microbiomes in the digestion of decaying wood. (shrink)

I hypothesize here that the ability of probiotics to synthesize neuroactive compounds provides a unifying microbial endocrinology‐based mechanism to explain the hitherto incompletely understood action of commensal microbiota that affect the host's gastrointestinal and psychological health. Once ingested, probiotics enter an interactive environment encompassing microbiological, immunological, and neurophysiological components. By utilizing a trans‐disciplinary framework known as microbial endocrinology, mechanisms that would otherwise not be considered become apparent since any candidate would need to be shared among all three components. The range (...) of neurochemicals produced by probiotics includes neurochemicals for which receptor‐based targets on immune and neuronal elements (intestinal and extra‐intestinal) have been well characterized. Production of neurochemicals by probiotics therefore allows for their consideration as delivery vehicles for neuroactive compounds. This unifying microbial endocrinology‐based hypothesis, which may facilitate the selection and design of probiotics for clinical use, also highlights the largely unrecognized role of neuroscience in understanding how microbes may influence health.Editor's suggested further reading in BioEssays Harvesting the biological potential of the human gut microbiome Abstract. (shrink)

Our culture and its scientific endeavor direly need a holistic characterization of mind and body. Many phenomena attest to the profound effects of beliefs on bodily function (e.g., open-label placebo's effects on chronic pain) and interoceptive systems’ role in mental processes (e.g., the emerging role of gut microbiomes in the mood). We need a mechanistic, integrative framework to account for these phenomena and generate novel predictions. Major advances have been made in understanding how the nervous system senses and regulates the (...) body and in modeling how the brain implements the computations that subserve such activities. However, the vestiges of Cartesianism have entrained a style of thinking in which systems from the brainstem downward exist as the implementation layer of computational processes supporting sensation and behavior, rather than a complementary locus of information processing. As speakers and microphones, rather than other members of the chorus. We are thus forced to perceive well-documented, belief-driven phenomena like placebo, ritual, and psychosomatic disorders as mysterious obstacles or dubious allies rather than as a wellspring of potential. (shrink)

Animals exist as biodiverse composite organisms that include microbial residents, eukaryotic cells, and organs that collectively form a human being. Through an interdependent relationship and an inherent ability to transmit and reciprocate stimuli in a bidirectional way, a human body or the holobiont secures growth, health, and reproduction. As such, the survival of a holobiont is dependent on the maintenance of biological order including metabolic homeostasis by tight regulation of the communication between its eukaryotic and prokaryotic residents. In this review (...) an overview and perspective are provided on the bidirectional communication between microbes and their host in mutually nurturing biochemical, biological, and social interconnected relationships between the components of the holobiont. An emphasis is placed on exemplifying microbiome‐mediated effects on host functions—aiming to integrate microbiome functionality to host physiology, be it health or disease. Nutrition, immunology, and sexual dimorphism have been traversed extensively to reflect on health and mind states, social interactions, and urbanization defects/effects. Finally, examples of molecular mechanisms potentially orchestrating these complex transkingdom interactions are provided. (shrink)

uBiome offers a gut bacteria sequencing service to consumers to entice data donation. It aims to establish a genomic repository for microbiomics. In 2013, some bloggers worried that uBiome operations had not received any Institutional Review Board ethics approval. uBiome co-founders Richman and Apte replied by effectively arguing that crony research agencies hamper innovation by requiring cumbersome for-fee IRBs to so-called “citizen science” projects. The debate soon ascended from ethics to appropriate institutional design for research and innovation. I reconstruct the (...) ethical issues underpinning the uBiome-IRB debate and situate them in the emerging context of entrepreneurial science relying on crowdsourcing. This paper contributes to the dialogue between social scientists and bioethicists promoted in this volume by offering an analysis of a case study that requires attention to the organizational and economic context and lends itself to collaboration across disciplines. (shrink)

“Dysbiosis” is a common but vague term featured in the microbiome literature, often invoked to indicate some kind of imbalance among microbiota. There is no agreement on how to define or even characterize dysbiotic microbiomes. Building on the work of Morar and Bohannan, who explore five interpretations of “microbiome,” I offer a short supplemental analysis of what plausibly counts as “dysbiosis” according to each of the five distinct conceptions. My aim is to provide a more nuanced basis for (...) interpreting claims, primarily and most generally; and more specifically, provide a basis for those advancing pluralist or eliminativist arguments. (shrink)

The conclusions reached by Hooks et al. urge the field to investigate the complex multipathway interactions between the microbiome and the gut-brain axis to understand the potential causal relationships involved. Claims in the field of microbiota-gut-brain research remain problematic without appropriate controls and adequate statistical power. A crucial question that follows from the authors' extensive review is: “Why don't probiotics work?”.

The de‐repression of transposable elements (TEs) in mammalian genomes is thought to contribute to genome instability, inflammation, and ageing, yet is viewed as a cell‐autonomous event. In contrast to mammalian cells, prokaryotes constantly exchange genetic material through TEs, crossing both cell and species barriers, contributing to rapid microbial evolution and diversity in complex communities such as the mammalian gut. Here, it is proposed that TEs released from prokaryotes in the microbiome or from pathogenic infections regularly cross the kingdom barrier (...) to the somatic cells of their eukaryotic hosts. It is proposed this horizontal transfer of TEs from microbe to host is a stochastic, ongoing catalyst of genome destabilization, resulting in structural and epigenetic variations, and activation of well‐evolved host defense mechanisms contributing to inflammation, senescence, and biological ageing. It is proposed that innate immunity pathways defend against the horizontal acquisition of microbial TEs, and that activation of this pathway during horizontal transposon transfer promotes chronic inflammation during ageing. Finally, it is suggested that horizontal acquisition of prokaryotic TEs into mammalian genomes has been masked and subsequently under‐reported due to flaws in current sequencing pipelines, and new strategies to uncover these events are proposed. (shrink)

We are mastering engineering behaviour on a molecular level. A growing number of researches investigating the relationship between microbiota, human brain and behaviour examine the impacts of manipulating specific microbial colonies in human hosts. To enable discussing and understanding communicational phenomena that occur in scales not visible to the naked eye, we propose the term Molmedia – a metaphorical reference to the concept of mole, denoting here not exclusively the quantitative amount of substance but the information exchange processes (taking the (...) substances as messages) that are going on at elementary entities level such as atomic, subatomic and molecular, within a given system that can be a living organism. We take media (plural of medium) as an intervening agency, means or instrument. Interacting emitters and receivers in this system are the microbiota and the organism actual cells. Within this self-organizing structure, the ongoing informational processes produce, as an emergence, the self and behavioral patterns that can be appreciated, manipulated and cannibalized. The art and science installation Transplanting the Self: Microbiome Anthropophagy is presented as an explorative exercise of the concept and related possibilities in science concerning gut–brain communication and the use of neuroregenerative nutrition in treatments for neurologic conditions. (shrink)

Microbes in the gastrointestinal tract are under selective pressure to manipulate host eating behavior to increase their fitness, sometimes at the expense of host fitness. Microbes may do this through two potential strategies: (i) generating cravings for foods that they specialize on or foods that suppress their competitors, or (ii) inducing dysphoria until we eat foods that enhance their fitness. We review several potential mechanisms for microbial control over eating behavior including microbial influence on reward and satiety pathways, production of (...) toxins that alter mood, changes to receptors including taste receptors, and hijacking of the vagus nerve, the neural axis between the gut and the brain. We also review the evidence for alternative explanations for cravings and unhealthy eating behavior. Because microbiota are easily manipulatable by prebiotics, probiotics, antibiotics, fecal transplants, and dietary changes, altering our microbiota offers a tractable approach to otherwise intractable problems of obesity and unhealthy eating. (shrink)

In this review, we provide an overview of the dynamic changes within the microbiota and its metabolites that are implicated in establishing and maintaining gastrointestinal homeostasis during various stages of microbial colonization. The gradual conversion of the gut microbiota toward a mutualistic microbial community involves replacement of pioneer gut colonizers with bacterial taxa that are characteristic for the adult gut. An important microbial signature of homeostasis in the adult gut is the prevalence and activity of a diverse spectrum of bacterial (...) species that produce beneficial metabolites through metabolic interactions between microbial groups. Deciphering these microbial signatures and their metabolites that govern short and long‐term equilibrium, as well as imbalances in host‐microbial relationships, may provide novel diagnostic tools and/or therapeutic targets for specific disorders associated with intestinal dysbiosis and loss of homeostasis. (shrink)

Large‐scale characterization of the human microbiota has largely focused on Western adults, yet these populations may be uncharacteristic because of their diets and lifestyles. In particular, the rise of “Western diseases” may in part stem from reduced exposure to, or even loss of, microbes with which humans have coevolved. Here, we review beneficial microbes associated with pathogen resistance, highlighting the emerging role of complex microbial communities in protecting against disease. We discuss ways in which modern lifestyles and practices may deplete (...) physiologically important microbiota, and explore prospects for reintroducing or encouraging the growth of beneficial microbes to promote the restoration of healthy microbial ecosystems. (shrink)

In this book Gary Gutting offers a powerful account of the nature of human reason in modern times. The fundamental question addressed by the book is what authority human reason can still claim once it is acknowledged that our fundamental metaphysical and religious pictures of the world no longer command allegiance. If ethics and science remain sources of authority what is the basis of that authority? Gutting develops answers to these questions through critical analysis of the work of three dominant (...) philosophical voices in our time: Richard Rorty, Alasdair MacIntyre, and Charles Taylor. His own position is defined as 'pragmatic liberalism'. (shrink)