The intersection of social determinants of health,the microbiome,and health outcomes in immigrants: A scoping review

In the present scoping review, we explore whether existing evidence supports the premise that social determinants of health (SDoH) affect immigrant health outcomes through their effects on the microbiome. We adapt the National Institute on Minority Health and Health Disparities' research framework to propose a conceptual model that considers the intersection of SDoH, the microbiome, and health outcomes in immigrants. We use this conceptual model as a lens through which to explore recent research about SDoH, biological factors associated with changes to immigrants' microbiomes, and long-term health outcomes. In the 17 articles reviewed, dietary acculturation, physical activity, ethnicity, birthplace, age at migration and length of time in the host country, socioeconomic status, and social/linguistic acculturation were important determinants of postmigration microbiome-related transformations. These factors are associated with progressive shifts in microbiome profile with time in host country, increasing the risks for cardiometabolic, mental, immune, and inflammatory disorders and antibiotic resistance. The evidence thus supports the premise that SDoH influence immigrants' health postmigration, at least in part, through their effects on the microbiome. Omission of important postmigration social-ecological variables (e.g., stress, racism, social/family relationships, and environment), limited research among minoritized subgroups of immigrants, complexity and inter- and intra-individual differences in the microbiome, and limited interdisciplinary and biosocial collaboration restrict our understanding of this area of study. To identify potential microbiome-based interventions and promote immigrants' well-being, more research is necessary to understand the intersections of immigrant health with factors from the biological, behavioral/psychosocial, physical/built environment, and sociocultural environment domains at all social-ecological levels.     

无菌动物及其在微生物与宿主互作机制研究中的应用

无菌动物是指通过现代技术手段在其体内外的任何部位均检测不出细菌、真菌、放线菌、支原体、衣原体、螺旋体、立克次氏体、病毒、原生动物和寄生虫的动物。无菌动物因其不携带任何微生物,可转化为携带特定微生物的动物,同时因其免疫系统处于休眠状态,对微生物感染异常敏感,可建立多种悉生动物模型,用于特定微生物感染实验和致病机制研究。此外,无菌动物作为关键工具,是研究菌群与疾病关系的核心,在微生物与宿主健康、疾病和感染机制研究过程中,起着不可替代的作用。本文将对无菌动物及其在微生物与宿主互作机制研究中的应用进行简要综述。     

膳食脂肪、肠道微生物与宿主健康的研究进展

作为三大主要营养物质之一,膳食脂肪为人体提供能量和营养。膳食脂肪摄入不当会破坏肠道微生物的稳态,影响宿主的代谢状况,增加慢性疾病发生的风险。建立疾病动物模型是研究肠道微生物与宿主健康的重要手段。文中综述了膳食脂质的数量和种类、肠道微生物和宿主代谢之间的相互作用及其可能的作用机制,阐述了基于不同的疾病动物模型,膳食脂质影响肠道微生物的结构和功能,以及对宿主代谢的调节,为深入了解膳食脂质、肠道微生态和宿主健康三者之间的关系提供了依据。     

Legume biofortification is an underexploited strategy for combatting hidden hunger

Legumes are the world's primary source of dietary protein and are particularly important for those in developing economies. However, the biofortification potential of legumes remains underexploited. Legumes offer a diversity of micronutrients and amino acids, exceeding or complementing the profiles of cereals. As such, the enhancement of legume nutritional composition presents an appealing target for addressing the “hidden hunger” of global micronutrient malnutrition. Affecting ~2 billion people, micronutrient malnutrition causes severe health effects ranging from stunted growth to reduced lifespan. An increased availability of micronutrient‐enriched legumes, particularly to those in socio‐economically deprived areas, would serve the dual functions of ameliorating hidden hunger and increasing the positive health effects associated with legumes. Here, we give an updated overview of breeding approaches for the nutritional improvement of legumes, and crucially, we highlight the importance of considering nutritional improvement in a wider ecological context. Specifically, we review the potential of the legume microbiome for agronomic trait improvement and highlight the need for increased genetic, biochemical, and environmental data resources. Finally, we state that such resources should be complemented by an international and multidisciplinary initiative that will drive crop improvement and, most importantly, ensure that research outcomes benefit those who need them most.     

Evolutionary “Experiments” in Symbiosis: The Study of Model Animals Provides Insights into the Mechanisms Underlying the Diversity of Host–Microbe Interactions

Current work in experimental biology revolves around a handful of animal species. Studying only a few organisms limits science to the answers that those organisms can provide. Nature has given us an overwhelming diversity of animals to study, and recent technological advances have greatly accelerated the ability to generate genetic and genomic tools to develop model organisms for research on host–microbe interactions. With the help of such models the authors therefore hope to construct a more complete picture of the mechanisms that underlie crucial interactions in a given metaorganism (entity consisting of a eukaryotic host with all its associated microbial partners). As reviewed here, new knowledge of the diversity of host–microbe interactions found across the animal kingdom will provide new insights into how animals develop, evolve, and succumb to the disease.     

Focus: Microbiome: Distinct Ecological Niche of Anal,Oral, and Cervical Mucosal Microbiomes in Adolescent Women

Human body sites represent ecological niches for microorganisms, each providing variations in microbial exposure, nutrient availability, microbial competition, and host immunological responses. In this study, we investigated the oral, anal, and cervical microbiomes from the same 20 sexually active adolescent females, using culture-independent, next-generation sequencing. DNA from each sample was amplified for the bacterial 16S rRNA gene and sequenced on an Illumina platform using paired-end reads. Across the three anatomical niches, we found significant differences in bacterial community composition and diversity. Overall anal samples were dominated with Prevotella and Bacteriodes, oral samples with Streptococcus and Prevotella, and cervical samples with Lactobacillus. The microbiomes of a few cervical samples clustered with anal samples in weighted principal coordinate analyses, due in part to a higher proportion of Prevotella in those samples. Additionally, cervical samples had the lowest alpha diversity. Our results demonstrate the occurrence of distinct microbial communities across body sites within the same individual.     

Consequences of colonialism: A microbial perspective to contemporary Indigenous health

Nearly all Indigenous populations today suffer from worse health than their non‐Indigenous counterparts, and despite interventions against known factors, this health “gap” has not improved. The human microbiome—the beneficial, diverse microbial communities that live on and within the human body—is a crucial component in developing and maintaining normal physiological health. Disrupting this ecosystem has repercussions for microbial functionality, and thus, human health. In this article, we propose that modern‐day Indigenous population health may suffer from disrupted microbial ecosystems as a consequence of historical colonialism. Colonialism may have interrupted the established relationships between the environment, traditional lifeways, and microbiomes, altering the Indigenous microbiome with detrimental health consequences.     

Safety and risk assessment for the human superorganism

This editorial on safety evaluation and risk assessment for the human superorganism introduces a series of papers arguing for a fundamental shift in how we approach human health risk assessment. In this series emphasis is placed on the risk of infectious disease. Our 21^stst century understanding of human biology is that, as holobionts, we possess a majority of microbial cells and genes. In fact, our microbes fundamentally affect our interactions with the external environment, metabolism, physiology, and risk of both pathology and disease. As holobionts, we require our microbial partners for us to be both complete and healthy. Using the 20^th century understanding of human biology, we failed to capture the effects of the microbiome in evaluating health risks. But 21^st century risk assessments such as those associated with exposure to specific microbial pathogens need to include the human microbiome. Microbiome status will be central in determining the health risks for both individuals and populations.     

Early sexual dimorphism in the developing gut microbiome of northern elephant seals

The gut microbiome is an integral part of a species' ecology, but we know little about how host characteristics impact its development in wild populations. Here, we explored the role of such intrinsic factors in shaping the gut microbiome of northern elephant seals (Mirounga angustirostris) during a critical developmental window of 6 weeks after weaning, when the pups stay ashore without feeding. We found substantial sex differences in the early‐life gut microbiome, even though males and females could not yet be distinguished morphologically. Sex and age both explained around 15% of the variation in gut microbial beta diversity, while microbial communities sampled from the same individual showed high levels of similarity across time, explaining another 40% of the variation. Only a small proportion of the variation in beta diversity was explained by health status, assessed by full blood counts, but clinically healthy individuals had a greater microbial alpha diversity than their clinically abnormal peers. Across the post‐weaning period, the northern elephant seal gut microbiome was highly dynamic. We found evidence for several colonization and extinction events as well as a decline in Bacteroides and an increase in Prevotella, a pattern that has previously been associated with the transition from nursing to solid food. Lastly, we show that genetic relatedness was correlated with gut microbiome similarity in males but not females, again reflecting early sex differences. Our study represents a naturally diet‐controlled and longitudinal investigation of how intrinsic factors shape the early gut microbiome in a species with extreme sex differences in morphology and life history.     

根际微生物组组装与植物健康

土壤微生物拥有高度多样化的群落结构,其通过与植物发生复杂的相互作用影响植物健康,也被称为植物的第二基因组。最近研究表明植物能通过改变根际分泌物的组成影响根际微生物群落的组装,反之,根际微生物群落组成的改变能够通过影响植物营养吸收和抵御生物及非生物胁迫的能力影响植物健康。除此之外,农艺管理也是影响土壤微生物群落组装方式的重要因素。但到目前为止,根际微生物与宿主植物及土壤微生物之间互作机制的研究尚不清楚。本文将从农艺管理和宿主植物对微生物群落组装的影响及根际微生物组对植物健康的影响进行总结,为增加作物产量提供机会。     

Anatomy promotes neutral coexistence of strains in the human skin microbiome

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Application of ecological and evolutionary theory to microbiome community dynamics across systems

A fundamental aim of microbiome research is to understand the factors that influence the assembly and stability of host-associated microbiomes, and their impact on host phenotype, ecology and evolution. However, ecological and evolutionary theories applied to predict microbiome community dynamics are largely based on macroorganisms and lack microbiome-centric hypotheses that account for unique features of the microbiome. This special feature sets out to drive advancements in the application of eco-evolutionary theory to microbiome community dynamics through the development of microbiome-specific theoretical and conceptual frameworks across plant, human and non-human animal systems. The feature comprises 11 research and review articles that address: (i) the effects of the microbiome on host phenotype, ecology and evolution; (ii) the application and development of ecological and evolutionary theories to investigate microbiome assembly, diversity and stability across broad taxonomic scales; and (iii) general principles that underlie microbiome diversity and dynamics. This cross-disciplinary synthesis of theoretical, conceptual, methodological and analytical approaches to characterizing host–microbiome ecology and evolution across systems addresses key research gaps in the field of microbiome research and highlights future research priorities.