Home chemical and microbial transitions across urbanization

The power and potential of BIOMAP to elucidate host-microbiome interplay in skin inflammatory diseases

The two most common chronic inflammatory skin diseases are atopic dermatitis (AD) and psoriasis. The underpinnings of the remarkable degree of clinical heterogeneity of AD and psoriasis are poorly understood and, as a consequence, disease onset and progression are unpredictable and the optimal type and time-point for intervention are as yet unknown. The BIOMAP project is the first IMI (Innovative Medicines Initiative) project dedicated to investigating the causes and mechanisms of AD and psoriasis and to identify potential biomarkers responsible for the variation in disease outcome. The consortium includes 7 large pharmaceutical companies and 25 non-industry partners including academia. Since there is mounting evidence supporting an important role for microbial exposures and our microbiota as factors mediating immune polarization and AD and psoriasis pathogenesis, an entire work package is dedicated to the investigation of skin and gut microbiome linked to AD or psoriasis. The large collaborative BIOMAP project will enable the integration of patient cohorts, data and knowledge in unprecedented proportions. The project has a unique opportunity with a potential to bridge and fill the gaps between current problems and solutions. This review highlights the power and potential of BIOMAP project in the investigation of microbe-host interplay in AD and psoriasis.

Inactivation of common airborne antigens by perfluoroalkyl chemicals modulates early life allergic asthma

Allergic asthma, driven by T helper 2 cell-mediated immune responses to common environmental antigens, remains the most common respiratory disease in children. Perfluorinated chemicals (PFCs) are environmental contaminants of great concern, because of their wide application, persistence in the environment, and bioaccumulation. PFCs associate with immunological disorders including asthma and attenuate immune responses to vaccines. The influence of PFCs on the immunological response to allergens during childhood is unknown. We report here that a major PFC, perfluorooctane sulfonate (PFOS), inactivates house dust mite (HDM) to dampen 5-wk-old, early weaned mice from developing HDM-induced allergic asthma. PFOS further attenuates the asthma protective effect of the microbial product lipopolysaccharide (LPS). We demonstrate that PFOS prevents desensitization of lung epithelia by LPS, thus abolishing the latter's protective effect. A close mechanistic study reveals that PFOS specifically binds the major HDM allergen Der p1 with high affinity as well as the lipid A moiety of LPS, leading to the inactivation of both antigens. Moreover, PFOS at physiological human (nanomolar) concentrations inactivates Der p1 from HDM and LPS in vitro, although higher doses did not cause further inactivation because of possible formation of PFOS aggregates. This PFOS-induced neutralization of LPS has been further validated in primary human cell models and extended to an in vivo bacterial infection mouse model. This study demonstrates that early life exposure of mice to a PFC blunts airway antigen bioactivity to modulate pulmonary inflammatory responses, which may adversely affect early pulmonary health.

The Future of Functional Clothing for an Improved Skin and Textile Microbiome Relationship

The skin microbiome has become a hot field of research in the last few years. The emergence of next-generation sequencing has given unprecedented insights into the impact and involvement of microbiota in skin conditions. More and more cosmetics contain probiotics or bacteria as an active ingredient, with or without scientific data. This research is also acknowledged by the textile industry. There has been a more holistic approach on how the skin and textile microbiome interacts and how they influence the pH, moisture content and odour generation. To date, most of the ingredients have a broad-spectrum antibacterial action. This manuscript covers the current research and industry developments in the field of skin and textiles. It explores the nature of antimicrobial finishing in textiles which can disrupt the skin microbiome, and the benefits of more natural and microbiome friendly therapies to combat skin conditions, malodour and skin infection.

Challenges in exploring and manipulating the human skin microbiome

The skin is the exterior interface of the human body with the environment. Despite its harsh physical landscape, the skin is colonized by diverse commensal microbes. In this review, we discuss recent insights into skin microbial populations, including their composition and role in health and disease and their modulation by intrinsic and extrinsic factors, with a focus on the pathobiological basis of skin aging. We also describe the most recent tools for investigating the skin microbiota composition and microbe-skin relationships and perspectives regarding the challenges of skin microbiome manipulation. Video abstract.

Microbial exposures that establish immunoregulation are compatible with targeted hygiene

It is often suggested that hygiene is not compatible with the microbial exposures that are necessary for establishment of the immune system in early life. However, when we analyze the microbial exposures of modern humans in the context of human evolution and history, it becomes evident that whereas children need exposure to the microbiotas of their mothers, other family members, and the natural environment, exposure to the unnatural microbiota of the modern home is less relevant. In addition, any benefits of exposure to the infections of childhood within their household setting are at least partly replaced by the recently revealed nonspecific effects of vaccines. This article shows how targeting hygiene practices at key risk moments and sites can maximize protection against infection while minimizing any impact on essential microbial exposures. Moreover, this targeting must aim to reduce direct exposure of children to cleaning agents because those agents probably exert T_H2-adjuvant effects that trigger allergic responses to normally innocuous antigens. Finally, we need to halt the flow of publications in the scientific literature and the media that blame hygiene for the increases in immunoregulatory disorders. Appropriately targeted hygiene behavior is compatible with a healthy lifestyle that promotes exposure to essential microorganisms.

The microbiota-mediated dietary and nutritional interventions for COVID-19

Worldwide, scientists are looking for specific treatment for COVID-19. Apart from the antiviral approach, the interventions to support healthy immune responses to the virus are feasible through diet, nutrition, and lifestyle approaches. This narrative review explores the recent studies on dietary, nutritional, and lifestyle interventions that influence the microbiota-mediated immunomodulatory effects against viral infections. Cumulative studies reported that the airway microbiota and SARS-CoV-2 leverage each other and determine the pathogen-microbiota-host responses. Cigarette smoking can disrupt microbiota abundance. The composition and diversification of intestinal microbiota influence the airway microbiota and the innate and adaptive immunity, which require supports from the balance of macro- and micronutrients from the diet. Colorful vegetables supplied fermentable prebiotics and anti-inflammatory, antioxidant phytonutrients. Fermented foods and beverages support intestinal microbiota. In sensitive individuals, the avoidance of the high immunoreactive food antigens contributes to antiviral immunity. This review suggests associations between airway and intestinal microbiota, antiviral host immunity, and the influences of dietary, nutritional, and lifestyle interventions to prevent the clinical course toward severe COVID-19.

The infant gut resistome associates with E. coli, environmental exposures, gut microbiome maturity, and asthma-associated bacterial composition

Antimicrobial resistance (AMR) is an accelerating global threat, yet the nature of AMR in the gut microbiome and how AMR is acquired during early life remain largely unknown. In a cohort of 662 Danish children, we characterized the antibiotic resistance genes (ARGs) acquired during the first year of life and assessed the impacts of diverse environmental exposures on ARG load. Our study reveals a clear bimodal distribution of ARG richness that is driven by the composition of the gut microbiome, especially E. coli. ARG profiles were significantly affected by various environmental factors. Among these factors, the importance of antibiotics diminished with time since treatment. Finally, ARG load and ARG clusters were also associated with the maturity of the gut microbiome and a bacterial composition associated with increased risk of asthma. These findings broaden our understanding of AMR in early life and have critical implications for efforts to mitigate its spread.

Insight Into Microbial Community Aerosols Associated With Electronic Waste Handling Facilities by Culture-Dependent and Culture-Independent Methods

Airborne microorganisms in the waste associated environments are more active and complex compared to other places. However, the diversity and structure of airborne bacteria in waste-associated environments are still not clearly understood. The purpose of this study was to assess airborne bacterial community in electronic waste dismantling site and a waste transfer station based on culture-dependent and culture-independent methods. A total of 229 isolates were obtained from four airborne sites collected from residential area, electronic industrial park, and office area in or near an electronic waste dismantling site and a waste transfer station in Southern China in the morning, afternoon, and evening. Most of the isolates were isolated from air for the first time and 14 potentially novel species were identified by Sanger sequencing. Bacterial communities in waste-associated bioaerosols were predominated by Proteobacteria and Bacteroidetes. Abundant genera (>1%) included Paracaedibacteraceae (uncultured EF667926), Ralstonia, Chroococcidiopsis, Chitinophagaceae (uncultured FN428761), Sphingobium, and Heliimonas. One-third of the species in these genera were uncultured approximately. Differences community structure existed in airborne bacterial diversity among different sampling sites. These results showed that waste-associated environments have unique bacterial diversity. Further studies on such environments could provide new insights into bacterial community.

Human Skin Microbiome: Impact of Intrinsic and Extrinsic Factors on Skin Microbiota

The skin is the largest organ of the human body and it protects the body from the external environment. It has become the topic of interest of researchers from various scientific fields. Microorganisms ensure the proper functioning of the skin. Of great importance, are the mutual relations between such microorganisms and their responses to environmental impacts, as dysbiosis may contribute to serious skin diseases. Molecular methods, used for microorganism identification, allow us to gain a better understanding of the skin microbiome. The presented article contains the latest reports on the skin microbiota in health and disease. The review discusses the relationship between a properly functioning microbiome and the body's immune system, as well as the impact of internal and external factors on the human skin microbiome.

Jares E, Jarvis D, Jassem E, Jenko K, Jiméneracruz Uscanga RD, Johnston SL, Joos G, Jošt M, Julge K, Jung K, Just J, Jutel M, Kaidashev I, Kalayci O, Kalyoncu F, Kapsali J, Kardas P, Karjalainen J, Kasala CA, Katotomichelakis M, Kavaliukaite L, Kazi BS, Keil T, Keith P, Khaitov M, Khaltaev N, Kim Y, Kirenga B, Kleine‐Tebbe J, Klimek L, Koffi N’Goran B, Kompoti E, Kopač P, Koppelman G, KorenJeverica A, Koskinen S, Košnik M, Kostov KV, Kowalski ML, Kralimarkova T, Kramer Vrščaj K, Kraxner H, Kreft S, Kritikos V, Kudlay D, Kuitunen M, Kull I, Kuna P, Kupczyk M, Kvedariene V, Kyriakakou M, Lalek N, Landi M, Lane S, Larenas‐Linnemann D, Lau S, Laune D, Lavrut J, Le L, Lenzenhuber M, Lessa M, Levin M, Li J, Lieberman P, Liotta G, Lipworth B, Liu X, Lobo R, Lodrup Carlsen KC, Lombardi C, Louis R, Loukidis S, Lourenço O, Luna Pech JA, Madjar B, Maggi E, Magnan A, Mahboub B, Mair A, Mais Y, Maitland van der Zee A, Makela M, Makris M, Malling H, Mandajieva M, Manning P, Manousakis M, Maragoudakis P, Marseglia G, Marshall G, Reza Masjedi M, Máspero JF, Matta Campos JJ, Maurer M, Mavale‐Manuel S, Meço C, Melén E, Melioli G, Melo‐Gomes E, Meltzer EO, Menditto E, Menzies‐Gow A, Merk H, Michel J, Micheli Y, Miculinic N, Midão L, Mihaltan F, Mikos N, Milanese M, Milenkovic B, Mitsias D, Moalla B, Moda G, Mogica Martínez MD, Mohammad Y, Moin M, Molimard M, Momas I, Mommers M, Monaco A, Montefort S, Mora D, Morais‐Almeida M, Mösges R, Mostafa B, Mullol J, Münter L, Muraro A, Murray R, Musarra A, Mustakov T, Naclerio R, Nadeau KC, Nadif R, Nakonechna A, Namazova‐Baranova L, Navarro‐Locsin G, Neffen H, Nekam K, Neou A, Nettis E, Neuberger D, Nicod L, Nicola S, Niederberger‐Leppin V, Niedoszytko M, Nieto A, Novellino E, Nunes E, Nyembue D, O’Hehir R, Odjakova C, Ohta K, Okamoto Y, Okubo K, Oliver B, Onorato GL, Pia Orru M, Ouédraogo S, Ouoba K, Paggiaro PL, Pagkalos A, Pajno G, Pala G, Palaniappan S, Pali‐Schöll I, Palkonen S, Palmer S, Panaitescu Bunu C, Panzner P, Papadopoulos NG, Papanikolaou V, Papi A, Paralchev B, Paraskevopoulos G, Park H, Passalacqua G, Patella V, Pavord I, Pawankar R, Pedersen S, Peleve S, Pellegino S, Pereira A, Pérez T, Perna A, Peroni D, Pfaar O, Pham‐Thi N, Pigearias B, Pin I, Piskou K, Pitsios C, Plavec D, Poethig D, Pohl W, Poplas Susic A, Popov TA, Portejoie F, Potter P, Poulsen L, Prados‐Torres A, Prarros F, Price D, Prokopakis E, Puggioni F, Puig‐Domenech E, Puy R, Rabe K, Raciborski F, Ramos J, Recto MT, Reda SM, Regateiro FS, Reider N, Reitsma S, Repka‐Ramirez S, Ridolo E, Rimmer J, Rivero Yeverino D, Angelo Rizzo J, Robalo‐Cordeiro C, Roberts G, Roche N, Rodríguez González M, Rodríguez Zagal E, Rolla G, Rolland C, Roller‐Wirnsberger R, Roman Rodriguez M, Romano A, Romantowski J, Rombaux P, Romualdez J, Rosado‐Pinto J, Rosario N, Rosenwasser L, Rossi O, Rottem M, Rouadi P, Rovina N, Rozman Sinur I, Ruiz M, Ruiz Segura LT, Ryan D, Sagara H, Sakai D, Sakurai D, Saleh W, Salimaki J, Samitas K, Samolinski B, Sánchez Coronel MG, Sanchez‐Borges M, Sanchez‐Lopez J, Sarafoleanu C, Sarquis Serpa F, Sastre‐Dominguez J, Savi E, Sawaf B, Scadding GK, Scheire S, Schmid‐Grendelmeier P, Schuhl JF, Schunemann H, Schvalbová M, Schwarze J, Scichilone N, Senna G, Sepúlveda C, Serrano E, Shields M, Shishkov V, Siafakas N, Simeonov A, FER Simons E, Carlos Sisul J, Sitkauskiene B, Skrindo I, SokličKošak T, Solé D, Sooronbaev T, Soto‐Martinez M, Soto‐Quiros M, Sousa Pinto B, Sova M, Soyka M, Specjalski K, Spranger O, Stamataki S, Stefanaki L, Stellato C, Stelmach R, Strandberg T, Stute P, Subramaniam A, Suppli Ulrik C, Sutherland M, Sylvestre S, Syrigou A, Taborda Barata L, Takovska N, Tan R, Tan F, Tan V, Ping Tang I, Taniguchi M, Tannert L, Tantilipikorn P, Tattersall J, Tesi F, Thijs C, Thomas M, To T, Todo‐Bom A, Togias A, Tomazic P, Tomic‐Spiric V, Toppila‐Salmi S, Toskala E, Triggiani M, Triller N, Triller K, Tsiligianni I, Uberti M, Ulmeanu R, Urbancic J, Urrutia Pereira M, Vachova M, Valdés F, Valenta R, Valentin Rostan M, Valero A, Valiulis A, Vallianatou M, Valovirta E, Van Eerd M, Van Ganse E, Hage M, Vandenplas O, Vasankari T, Vassileva D, Velasco Munoz C, Ventura MT, Vera‐Munoz C, Vicheva D, Vichyanond P, Vidgren P, Viegi G, Vogelmeier C, Von Hertzen L, Vontetsianos T, Vourdas D, Tran Thien Quan V, Wagenmann M, Walker S, Wallace D, Wang DY, Waserman S, Wickman M, Williams S, Williams D, Wilson N, Wong G, Woo K, Wright J, Wroczynski P, Xepapadaki P, Yakovliev P, Yamaguchi M, Yan K, Yeow Yap Y, Yawn B, Yiallouros P, Yorgancioglu A, Yoshihara S, Young I, Yusuf OB, Zaidi A, Zaitoun F, Zar H, Zedda M, Zernotti ME, Zhang L, Zhong N, Zidarn M, Zubrinich C. Cabbage and fermented vegetables: From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID‐19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS‐CoV‐2 binds to its receptor, the angiotensin‐converting enzyme 2 (ACE2). As a result of SARS‐CoV‐2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT₁R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID‐19. The nuclear factor (erythroid‐derived 2)‐like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT₁R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof‐of‐concept of dietary manipulations that may enhance Nrf2‐associated antioxidant effects, helpful in mitigating COVID‐19 severity.

Quo vadis? Central Rules of Pathogen and Disease Tropism

Understanding why certain people get sick and die while others recover or never become ill is a fundamental question in biomedical research. A key determinant of this process is pathogen and disease tropism: the locations that become infected (pathogen tropism), and the locations that become damaged (disease tropism). Identifying the factors that regulate tropism is essential to understand disease processes, but also to drive the development of new interventions. This review intersects research from across infectious diseases to define the central mediators of disease and pathogen tropism. This review also highlights methods of study, and translational implications. Overall, tropism is a central but under-appreciated aspect of infection pathogenesis which should be at the forefront when considering the development of new methods of intervention.

Gut Microbial Composition Differs Extensively among Indian Native Chicken Breeds Originated in Different Geographical Locations and a Commercial Broiler Line, but Breed-Specific, as Well as Across-Breed Core Microbiomes, Are Found

Gut microbiota plays an important role in the health and performance of the host. Characterizations of gut microbiota, core microbiomes, and microbial networks in different chicken breeds are expected to provide clues for pathogen exclusion, improving performance or feed efficiency. Here, we characterized the gut microbiota of “finishing” chickens (at the end of production life) of indigenous Indian Nicobari, Ghagus, and Aseel breeds, originating from the Nicobari island, coastal India, and the Indian mainland, respectively, as well as a global commercial broiler line, VenCobb 400, using 16S rDNA amplicon sequencing. We found that diversity, as well as richness of microbiota, was higher in indigenous breeds than in the broiler line. Beta diversity analysis indicated the highest overlap between Ghagus and Nicobari breeds and a very low overlap between the broiler line and all indigenous breeds. Linear discriminant analysis effect size (LEfSe) revealed 82 breed- or line-specific phylotype operational taxonomic unit (OTU) level biomarkers. We confirm the presence of breed specific and across-breed core microbiomes. Additionally, we show the existence of breed specific complex microbial networks in all groups. This study provides the first (and comprehensive) insight into the gut microbiota of three indigenous breeds and one commercial broiler line of chickens reared without antimicrobials, and underscores the need to study microbial diversity in other indigenous breeds.

Gut-Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions

The microbiome plays an important role in a wide variety of skin disorders. Not only is the skin microbiome altered, but also surprisingly many skin diseases are accompanied by an altered gut microbiome. The microbiome is a key regulator for the immune system, as it aims to maintain homeostasis by communicating with tissues and organs in a bidirectional manner. Hence, dysbiosis in the skin and/or gut microbiome is associated with an altered immune response, promoting the development of skin diseases, such as atopic dermatitis, psoriasis, acne vulgaris, dandruff, and even skin cancer. Here, we focus on the associations between the microbiome, diet, metabolites, and immune responses in skin pathologies. This review describes an exhaustive list of common skin conditions with associated dysbiosis in the skin microbiome as well as the current body of evidence on gut microbiome dysbiosis, dietary links, and their interplay with skin conditions. An enhanced understanding of the local skin and gut microbiome including the underlying mechanisms is necessary to shed light on the microbial involvement in human skin diseases and to develop new therapeutic approaches.

Skin microbiome transplantation and manipulation: Current state of the art

Many skin conditions are associated with an imbalance in the skin microbiome. In recent years, the skin microbiome has become a hot topic, for both therapeutic and cosmetic purposes. The possibility of manipulating the human skin microbiome to address skin conditions has opened exciting new paths for therapy. Here we review the skin microbiome manipulation strategies, ranging from skin microbiome transplantation, over skin bacteriotherapy to the use of prebiotics, probiotics and postbiotics. We summarize all efforts undertaken to exchange, manipulate, transplant or selectively apply the skin microbiome to date. Multiple microbial groups have been targeted, since they have been proven to be beneficial for skin health. We focus on the most common skin disorders and their associated skin microbiome dysbiosis and we review the existing scientific data and clinical trials undertaken to combat these skin conditions. The skin microbiome represents a novel platform for therapy. Transplantation of a complete microbiome or application of single strains has demonstrated beneficial therapeutic application.

Can we prevent allergic disease? Understanding the links between the early life microbiome and allergic diseases of childhood

PURPOSE OF REVIEW

The microbiome and immune system are intrinsically linked, and during infancy these crucial biological systems undergo a concurrent and expansive maturation process. As these maturation processes progress, some children develop a sequence of IgE-mediated immune disorders termed the 'Allergic March', and unfortunately the prevalence of these lifelong and burdensome allergic conditions has increased over the past half century. Our current treatment strategies are unable to prevent or cure components of the Allergic March. However, recent discoveries have enhanced our mechanistic understanding of early-life microbiota-immune interactions with exciting implications for preventing these allergic disorders.

RECENT FINDINGS

The current review will detail recent literature regarding perinatal factors (e.g. birth mode, antibiotic exposure, breastmilk seeding of the microbiota, built environment) that shape the infant gut microbiota composition. Furthermore, we will discuss new findings that have highlighted immune cells which are particularly sensitive to microbial influences in utero and during the early-life window of development.

SUMMARY

As our understanding of the dynamic relationship between the developing infant microbiota and immune system grows, a priority toward preserving critical early-life interactions may provide life-long protection to these diseases in the future.

Biological and Chemical Processes that Lead to Textile Malodour Development

The development of malodour on clothing is a well-known problem with social, economic and ecological consequences. Many people still think malodour is the result of a lack of hygiene, which causes social stigma and embarrassment. Clothing is washed more frequently due to odour formation or even discarded when permastink develops. The malodour formation process is impacted by many variables and processes throughout the textile lifecycle. The contact with the skin with consequent transfer of microorganisms, volatiles and odour precursors leads to the formation of a distinctive textile microbiome and volatilome. The washing and drying processes further shape the textile microbiome and impact malodour formation. These processes are impacted by interindividual differences and fabric type as well. This review describes the current knowledge on the volatilome and microbiome of the skin, textile and washing machine, the multiple factors that determine malodour formation on textiles and points out what information is still missing.

How do Rural Second Homes Affect Human Health and Well-being? Review of Potential Impacts

Contact with nature is associated with numerous psychological, physiological and social health and well-being benefits. Outdoor recreation, such as rural second home tourism, provides extensive exposure to the natural environment, but research around health impacts of this exposure is scattered. We review current research on health and well-being impacts of nature and discuss how the characteristics of rural second home environments and their use and users can affect these potential impacts in Finland. We discover four key issues affecting the impacts. First, health and well-being impacts depend on the users; urban people can especially benefit from rural second homes, while child development and the performance of elderly people can also be supported by contact with nature at second homes. Second, the regularity, length and season of second home visits influence the potential to receive benefits as they have an impact on the intensity of nature exposure. Third, the type and quality of second home environment affect contact with nature, such as exposure to health-supporting environmental microbes. Fourth, practices, motives and meanings modify activities and attachment and crucially affect both physical and mental well-being. We conclude that rural second homes have extensive potential to provide nature-related health and well-being benefits and further research is needed.

Skin Microbiome and its Interplay with the Environment

Advances in sequencing, bioinformatics and analytics now allow the structure, function and interrelations of whole microbial communities to be studied in greater detail. Collaborative efforts and multidisciplinary studies, crossing the boundary between environmental and medical microbiology, have allowed specific environmental, animal and human microbiomes to be characterized. One of the main challenges for microbial ecology is to link the phylogenetic diversity of host-associated microbes to their functional roles within the community. Much remains to be learned on the way microbes colonize the skin of different living organisms and the way the skin microbiome reacts to the surrounding environment (air, water, etc.). In this review, we discuss examples of recent studies that have used modern technology to provide insights into microbial communities in water and on skin, such as those in natural resources (thermal spring water), large mammals (humpback whales) and humans (the skin microbiome). The results of these studies demonstrate how a greater understanding of the structure and functioning of microbiota, together with their interactions with the environment, may facilitate the discovery of new probiotics or postbiotics, provide indicators for the quality of the environment, and show how changes in lifestyle and living environment, such as urbanization, can impact on the skin microbiome and skin health and disease in humans.

The Effects of Urbanization on the Infant Gut Microbiota and Health Outcomes

Humans and their gut microbiota have co-evolved over thousands of years, resulting in the establishment of a complex host-microbiota ecosystem. Early life environmental factors, such as delivery mode, nutrition, and medication use, have been shown to substantially affect both host-microbiota interactions and health outcomes. However, the effects of urbanization (characterized by the spectrum of rural and urban populations) on these early life events have been overlooked. A deeper understanding of the relationship between urbanization and microbiota development will allow for the identification of novel biological and social approaches that can be implemented to prevent and treat disease and promote maternal and infant/child health. The aim of this narrative review is to summarize how factors associated with urbanization differentially impact delivery mode, nutrition, and medication use, and how these changes subsequently affect the gut microbiota and health outcomes of infants. This narrative review also describes the important evidence gaps associated with these relationships and recommends actions that can be taken to improve the health of mothers and infants worldwide.

Dynamics of Skin Mycobiome in Infants

Understanding the microbial community structure of the human skin is important for treating cutaneous diseases; however, little is known regarding skin fungal communities (mycobiomes). The aim of the present study was to investigate the features of and variations in skin fungal communities during infancy in 110 subjects less than 6 months of age. Skin samples were obtained from the back, antecubital fossa, and volar forearm, while physiological parameters including transepidermal water loss, pH, surface moisture, and deep layer hydration were evaluated. Skin fungal diversity decreased after the first three months of life. Differences in fungal community composition were greater among individual infants than among the three skin sites in the same individual. Inter- and intra-individual variation were similar and lower, respectively, than the variability between two samples obtained 12 weeks apart, from the same site in the same subject, suggesting low stability of fungal communities on infant skin. Skin physiological parameters showed little correlation with skin fungal community structure. Additionally, Malassezia was the most represented genus (36.43%) and M. globosa was the most abundant species in Malassezia with its abundance decreasing from 54.06% at 0–2 months to 34.54% at 5–6 months. These findings provide a basis for investigating the causative fungi-skin interactions associated with skin diseases.

Evolutionary development and co-phylogeny of primate-associated bifidobacteria

In recent years, bifidobacterial populations in the gut of various monkey species have been assessed in several ecological surveys, unveiling a diverse, yet unexplored ecosystem harbouring novel species. In the current study, we investigated the species distribution of bifidobacteria present in 23 different species of primates, including human samples, by means of 16S rRNA microbial profiling and internal transcribed spacer bifidobacterial profiling. Based on the observed bifidobacterial-host co-phylogeny, we found a statistically significant correlation between the Hominidae family and particular bifidobacterial species isolated from humans, indicating phylosymbiosis between these lineages. Furthermore, phylogenetic and glycobiome analyses, based on 40 bifidobacterial species isolated from primates, revealed that members of the Bifidobacterium tissieri phylogenetic group, which are typical gut inhabitants of members of the Cebidae family, descend from an ancient ancestor with respect to other bifidobacterial taxa isolated from primates.

Local Phenomena Shape Backyard Soil Metabolite Composition

Soil covers most of Earth's continental surface and is fundamental to life-sustaining processes such as agriculture. Given its rich biodiversity, soil is also a major source for natural product drug discovery from soil microorganisms. However, the study of the soil small molecule profile has been challenging due to the complexity and heterogeneity of this matrix. In this study, we implemented high-resolution liquid chromatography-tandem mass spectrometry and large-scale data analysis tools such as molecular networking to characterize the relative contributions of city, state and regional processes on backyard soil metabolite composition, in 188 soil samples collected from 14 USA States, representing five USA climate regions. We observed that region, state and city of collection all influence the overall soil metabolite profile. However, many metabolites were only detected in unique sites, indicating that uniquely local phenomena also influence the backyard soil environment, with both human-derived and naturally-produced (plant-derived, microbially-derived) metabolites identified. Overall, these findings are helping to define the processes that shape the backyard soil metabolite composition, while also highlighting the need for expanded metabolomic studies of this complex environment.