Indoor green wall affects health-associated commensal skin microbiota and enhances immune regulation : A randomized trial among urban office workers

Urbanization reduces microbiological abundance and diversity, which has been associated with immune mediated diseases. Urban greening may be used as a prophylactic method to restore microbiological diversity in cities and among urbanites. This study evaluated the impact of air-circulating green walls on bacterial abundance and diversity on human skin, and on immune responses determined by blood cytokine measurements. Human subjects working in offices in two Finnish cities (Lahti and Tampere) participated in a two-week intervention, where green walls were installed in the rooms of the experimental group. Control group worked without green walls. Skin and blood samples were collected before (Day0), during (Day14) and two weeks after (Day28) the intervention. The relative abundance of genus Lactobacillus and the Shannon diversity of phylum Proteobacteria and class Gammaproteobacteria increased in the experimental group. Proteobacterial diversity was connected to the lower proinflammatory cytokine IL-17A level among participants in Lahti. In addition, the change in TGF-beta 1 levels was opposite between the experimental and control group. As skin Lactobacillus and the diversity of Proteobacteria and Gammaproteobacteria are considered advantageous for skin health, air-circulating green walls may induce beneficial changes in a human microbiome. The immunomodulatory potential of air-circulating green walls deserves further research attention.Peer reviewe

Diverse Environmental Microbiota as a Tool to Augment Biodiversity in Urban Landscaping Materials

Human activities typically lead to simplified urban diversity, which in turn reduces microbial exposure and increases the risk to urban dwellers from non-communicable diseases. To overcome this, we developed a microbial inoculant from forest and agricultural materials that resembles microbiota in organic soils. Three different sand materials (sieved, safety and sandbox) commonly used in playgrounds and other public spaces were enriched with 5 % of the inoculant. Skin microbiota on fingers (identified from bacterial 16S rDNA determined using Illumina MiSeq sequencing) was compared after touching non-enriched and microbial inoculant-enriched sands. Exposure to the non-enriched materials changed the skin bacterial community composition in distinct ways. When the inoculant was added to the materials, the overall shift in community composition was larger and the differences between different sand materials almost disappeared. Inoculant-enriched sand materials increased bacterial diversity and richness but did not affect evenness at the OTU level on skin. The Firmicutes/Bacteroidetes ratio was higher after touching inoculant-enriched compared to non-enriched sand materials. The relative abundance of opportunistic pathogens on skin was 40–50 % before touching sand materials, but dropped to 14 % and 4 % after touching standard and inoculant-enriched sand materials, respectively. When individual genera were analyzed, Pseudomonas sp. and Sphingomonas sp. were more abundant after touching standard, non-enriched sand materials, while only the relative abundance of Chryseobacterium sp. increased after touching the inoculant-enriched materials. As Chryseobacterium is harmless for healthy persons, and as standard landscaping materials and normal skin contain genera that include severe pathogens , the inoculant-enriched materials can be considered safe. Microbial inoculants could be specifically created to increase the proportion of non-pathogenic bacterial taxa and minimize the transfer of pathogenic taxa. We recommend further study into the usability of inoculant-enriched materials and their effects on the bacterial community composition of human skin and on the immune response.Peer reviewe

Do Rural Second Homes Shape Commensal Microbiota of Urban Dwellers? : A Pilot Study among Urban Elderly in Finland

According to the hygiene and biodiversity hypotheses, increased hygiene levels and reduced contact with biodiversity can partially explain the high prevalence of immune-mediated diseases in developed countries. A disturbed commensal microbiota, especially in the gut, has been linked to multiple immune-mediated diseases. Previous studies imply that gut microbiota composition is associated with the everyday living environment and can be modified by increasing direct physical exposure to biodiverse materials. In this pilot study, the effects of rural-second-home tourism were investigated on the gut microbiota for the first time. Rural-second-home tourism, a popular form of outdoor recreation in Northern Europe, North America, and Russia, has the potential to alter the human microbiota by increasing exposure to nature and environmental microbes. The hypotheses were that the use of rural second homes is associated with differences in the gut microbiota and that the microbiota related to health benefits are more diverse or common among the rural-second-home users. Based on 16S rRNA Illumina MiSeq sequencing of stool samples from 10 urban elderly having access and 15 lacking access to a rural second home, the first hypothesis was supported: the use of rural second homes was found to be associated with lower gut microbiota diversity and RIG-I-like receptor signaling pathway levels. The second hypothesis was not supported: health-related microbiota were not more diverse or common among the second-home users. The current study encourages further research on the possible health outcomes or causes of the observed microbiological differences. Activities and diet during second-home visits, standard of equipment, surrounding environment, and length of the visits are all postulated to play a role in determining the effects of rural-second-home tourism on the gut microbiota

Effect of inactivated nature-derived microbial composition on mouse immune system

Introduction: The hygiene hypothesis suggests that decrease in early life infections due to increased societal-level hygiene standards subjects one to allergic and autoimmune diseases. In this report, we have studied the effect of sterilized forest soil and plant-based material on mouse immune system and gut microbiome. Methods: Inbred C57Bl/6 mice maintained in normal sterile environment were subjected to autoclaved forest soil-derived powder in their bedding for 1 h a day for 3 weeks. Immune response was measured by immune cell flow cytometry, serum cytokine enzyme-linked immunoassay (ELISA) and quantitative polymerase chain reaction (qPCR) analysis. Furthermore, the mouse gut microbiome was analyzed by sequencing. Results: When compared to control mice, mice treated with soil-derived powder had decreased level of pro-inflammatory cytokines namely interleukin (IL)-17F and IL-21 in the serum. Furthermore, splenocytes from mice treated with soil-derived powder expressed less IL-1b, IL-5, IL-6, IL-13, and tumor necrosis factor (TNF) upon cell activation. Gut microbiome appeared to be stabilized by the treatment. Conclusions: These results provide insights on the effect of biodiversity on murine immune system in sterile environment. Subjecting mice to soil-based plant and microbe structures appears to elicit immune response that could be beneficial, for example, in type 2 inflammation-related diseases, that is, allergic diseases.Peer reviewe

A Placebo-controlled double-blinded test of the biodiversity hypothesis of immune-mediated diseases : Environmental microbial diversity elicits changes in cytokines and increase in T regulatory cells in young children

Background: According to the biodiversity hypothesis of immune-mediated diseases, lack of microbiological di-versity in the everyday living environment is a core reason for dysregulation of immune tolerance and - even-tually - the epidemic of immune-mediated diseases in western urban populations. Despite years of intense research, the hypothesis was never tested in a double-blinded and placebo-controlled intervention trial.Objective: We aimed to perform the first placebo-controlled double-blinded test that investigates the effect of biodiversity on immune tolerance. Methods: In the intervention group, children aged 3-5 years were exposed to playground sand enriched with microbially diverse soil, or in the placebo group, visually similar, but microbially poor sand colored with peat (13 participants per treatment group). Children played twice a day for 20 min in the sandbox for 14 days. Sand, skin and gut bacterial, and blood samples were taken at baseline and after 14 days. Bacterial changes were followed for 28 days. Sand, skin and gut metagenome was determined by high throughput sequencing of bacterial 16 S rRNA gene. Cytokines were measured from plasma and the frequency of blood regulatory T cells was defined as a percentage of total CD3 +CD4 + T cells. Results: Bacterial richness (P < 0.001) and diversity (P < 0.05) were higher in the intervention than placebo sand. Skin bacterial community, including Gammaproteobacteria, shifted only in the intervention treatment to resemble the bacterial community in the enriched sand (P < 0.01). Mean change in plasma interleukin-10 (IL-10) concentration and IL-10 to IL-17A ratio supported immunoregulation in the intervention treatment compared to the placebo treatment (P = 0.02). IL-10 levels (P = 0.001) and IL-10 to IL-17A ratio (P = 0.02) were associated with Gammaproteobacterial community on the skin. The change in Treg frequencies was associated with the relative abundance of skin Thermoactinomycetaceae 1 (P = 0.002) and unclassified Alphaproteobacteria (P < 0.001). After 28 days, skin bacterial community still differed in the intervention treatment compared to baseline (P < 0.02). Conclusions: This is the first double-blinded placebo-controlled study to show that daily exposure to microbial biodiversity is associated with immune modulation in humans. The findings support the biodiversity hypothesis of immune-mediated diseases. We conclude that environmental microbiota may contribute to child health, and that adding microbiological diversity to everyday living environment may support immunoregulation.Peer reviewe

Biodiversity intervention enhances immune regulation and health-associated commensal microbiota among daycare children

As the incidence of immune-mediated diseases has increased rapidly in developed societies, there is an unmet need for novel prophylactic practices to fight against these maladies. This study is the first human intervention trial in which urban environmental biodiversity was manipulated to examine its effects on the commensal microbiome and immunoregulation in children. We analyzed changes in the skin and gut microbiota and blood immune markers of children during a 28-day biodiversity intervention. Children in standard urban and nature-oriented daycare centers were analyzed for comparison. The intervention diversified both the environmental and skin Gammaproteobacterial communities, which, in turn, were associated with increases in plasma TGF-beta 1 levels and the proportion of regulatory T cells. The plasma IL-10:IL-17A ratio increased among intervention children during the trial. Our findings suggest that biodiversity intervention enhances immunoregulatory pathways and provide an incentive for future prophylactic approaches to reduce the risk of immune-mediated diseases in urban societies.Peer reviewe

Endocrine disruption and commensal bacteria alteration associated with gaseous and soil PAH contamination among daycare children

Polycyclic aromatic hydrocarbons (PAHs) are priority environmental pollutants that cause adverse health effects. PAHs belong to endocrine signaling disruptors to which children are sensitive to. Recent evidence suggests that PAH pollution alters the abundance of environmental bacteria that is associated with health outcomes. The alteration of environmental and commensal microbiota by PAH pollution has never been connected to endocrine signaling pathways. To estimate the risk of endocrine disruption in daycare children, we measured PAHs from soil and air of eleven urban daycare centres in Finland. We analyzed daycare yards' soil and children's gut and skin bacterial communities with 16S rRNA gene metabarcoding and used Kyoto Encyclopaedia of Genes and Genomes database to categorize endocrine signaling pathways. We also assessed the PAH hazard to children's health based on the current risk assesments. We observed associations between signaling pathways in endocrine system and gaseous PAH levels in ambient air. Peroxisome proliferator-activated receptor and adipocytokine signaling pathway decreased with higher chrysene concentration in the air. Soil PAH contamination was associated with altered Actinobacteria, Bacteoridetes and Proteobacteria communities on children's skin and in daycare yard soil. However, adjusted genera were not the same in soil and on skin, with the exception of Mycobacterium that was associated with higher PAH concentrations both in soil and on the skin. Even though fluoranhtene levels were above the current threshold values, total PAHs were below safety threshold values and based on current risk assessments there is a minor risk for child health. Our findings indicate that PAH concentrations that are considered safe may interfere with endocrine signaling by commensal microbiota and alter both environmental and commensal bacterial communities. The imbalance in human microbiota and the decrease in signaling pathways may contribute to emerging public health problems, including inflammatory disorders, obesity and diabetes. Therefore, the optimal risk assessments of PAHs and theoretically also other contaminants shaping commensal microbiota may need to take into account the possibility of the disruption of endocrine signaling pathways.Peer reviewe

Yard vegetation is associated with gut microbiota composition

Gut microbes play an essential role in the development and functioning of the human immune system. A disturbed gut microbiota composition is often associated with a number of health disorders including immune-mediated diseases. Differences in host characteristics such as ethnicity, living habit and diet have been used to explain differences in the gut microbiota composition in inter-continental comparison studies. As our previous studies imply that daily skin contact with organic gardening materials modify gut microflora, here we investigated the association between living environment and gut microbiota in a homogenous western population along an urban-rural gradient. We obtained stool samples from 48 native elderly Finns in province Hame in August and November 2015 and identified the bacterial phylotypes using 16S rRNA Illumina MiSeq sequencing. We assumed that yard vegetation and land cover classes surrounding homes explain the stool bacterial community in generalized linear mixed models. Diverse yard vegetation was associated with a reduced abundance of Clostridium sensu stricto and an increased abundance of Faecalibacterium and Prevotellaceae. The abundance of Bacteroides was positively and strongly associated with the built environment. Exclusion of animal owners did not alter the main associations. These results suggest that diverse vegetation around homes is associated with health-related changes in gut microbiota composition. Manipulation of the garden diversity, possibly jointly with urban planning, is a promising candidate for future intervention studies that aim to maintain gut homeostasis. (C) 2020 The Authors. Published by Elsevier B.V.Peer reviewe

Recruitment and baseline data of the Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study: A randomized trial of a hearing loss intervention for reducing cognitive decline

INTRODUCTIONHearing loss is highly prevalent among older adults and independently associated with cognitive decline. The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study is a multicenter randomized control trial (partially nested within the infrastructure of an observational cohort study, the Atherosclerosis Risk in Communities [ARIC] study) to determine the efficacy of best-practice hearing treatment to reduce cognitive decline over 3 years. The goal of this paper is to describe the recruitment process and baseline results.METHODSMultiple strategies were used to recruit community-dwelling 70–84-year-old participants with adult-onset hearing loss who were free of substantial cognitive impairment from the parent ARIC study and de novo from the surrounding communities into the trial. Participants completed telephone screening, an in-person hearing, vision, and cognitive screening, and a comprehensive hearing assessment to determine eligibility.RESULTSOver a 24-month period, 3004 telephone screenings resulted in 2344 in-person hearing, vision, and cognition screenings and 1294 comprehensive hearing screenings. Among 1102 eligible, 977 were randomized into the trial (median age = 76.4 years; 53.5% female; 87.8% White; 53.3% held a Bachelor's degree or higher). Participants recruited through the ARIC study were recruited much earlier and were less likely to report hearing loss interfered with their quality of life relative to participants recruited de novo from the community. Minor differences in baseline hearing or health characteristics were found by recruitment route (i.e., ARIC study or de novo) and by study site.DISCUSSIONThe ACHIEVE study successfully completed enrollment over 2 years that met originally projected rates of recruitment. Substantial operational and scientific efficiencies during study startup were achieved through embedding this trial within the infrastructure of a longstanding and well-established observational study.HighlightsThe ACHIEVE study tests the effect of hearing intervention on cognitive decline.The study is partially nested within an existing cohort study.Over 2 years, 977 participants recruited and enrolled.Eligibility assessed by telephone and in-person for hearing, vision, and cognitive screening.The ACHIEVE study findings will have significant public health implications

Hearing loss and cognition: A protocol for ensuring speech understanding before neurocognitive assessment

INTRODUCTION: Many neurocognitive evaluations involve auditory stimuli, yet there are no standard testing guidelines for individuals with hearing loss. The ensuring speech understanding (ESU) test was developed to confirm speech understanding and determine whether hearing accommodations are necessary for neurocognitive testing. METHODS: Hearing was assessed using audiometry. The probability of ESU test failure by hearing status was estimated in 2679 participants (mean age: 81.4 ± 4.6 years) using multivariate logistic regression. RESULTS: Only 2.2% (N = 58) of participants failed the ESU test. The probability of failure increased with hearing loss severity; similar results were observed for those with and without mild cognitive impairment or dementia. DISCUSSION: The ESU test is appropriate for individuals who have variable degrees of hearing loss and cognitive function. This test can be used prior to neurocognitive testing to help reduce the risk of hearing loss and compromised auditory access to speech stimuli causing poorer performance on neurocognitive evaluation