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26 result(s) for "Karvonen, Anne M"
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Farm-like indoor microbiota in non-farm homes protects children from asthma development
Asthma prevalence has increased in epidemic proportions with urbanization, but growing up on traditional farms offers protection even today1. The asthma-protective effect of farms appears to be associated with rich home dust microbiota2,3, which could be used to model a health-promoting indoor microbiome. Here we show by modeling differences in house dust microbiota composition between farm and non-farm homes of Finnish birth cohorts4 that in children who grow up in non-farm homes, asthma risk decreases as the similarity of their home bacterial microbiota composition to that of farm homes increases. The protective microbiota had a low abundance of Streptococcaceae relative to outdoor-associated bacterial taxa. The protective effect was independent of richness and total bacterial load and was associated with reduced proinflammatory cytokine responses against bacterial cell wall components ex vivo. We were able to reproduce these findings in a study among rural German children2 and showed that children living in German non-farm homes with an indoor microbiota more similar to Finnish farm homes have decreased asthma risk. The indoor dust microbiota composition appears to be a definable, reproducible predictor of asthma risk and a potential modifiable target for asthma prevention.
Maturation of the gut microbiome during the first year of life contributes to the protective farm effect on childhood asthma
Growing up on a farm is associated with an asthma-protective effect, but the mechanisms underlying this effect are largely unknown. In the Protection against Allergy: Study in Rural Environments (PASTURE) birth cohort, we modeled maturation using 16S rRNA sequence data of the human gut microbiome in infants from 2 to 12 months of age. The estimated microbiome age (EMA) in 12-month-old infants was associated with previous farm exposure ( β  = 0.27 (0.12–0.43), P  = 0.001, n  = 618) and reduced risk of asthma at school age (odds ratio (OR) = 0.72 (0.56–0.93), P  = 0.011). EMA mediated the protective farm effect by 19%. In a nested case–control sample ( n  = 138), we found inverse associations of asthma with the measured level of fecal butyrate (OR = 0.28 (0.09–0.91), P  = 0.034), bacterial taxa that predict butyrate production (OR = 0.38 (0.17–0.84), P  = 0.017) and the relative abundance of the gene encoding butyryl–coenzyme A (CoA):acetate–CoA-transferase, a major enzyme in butyrate metabolism (OR = 0.43 (0.19–0.97), P  = 0.042). The gut microbiome may contribute to asthma protection through metabolites, supporting the concept of a gut–lung axis in humans. Growing up in the rich microbial environment of a farm strongly influences the maturation of the gut microbiome in the first year of life, which helps protect against the development of asthma in children.
Inspection confirmed mold damage in schools and new use of drugs for airway obstruction: A cohort study
New asthma is considered the most important possible long-term consequence of indoor dampness and mold. However, there are no prospective studies available from schools, there is insufficient evidence on dose-response, and no consensus on how exposure should be assessed. In Finland, visible mold is rare in schools and invasive methods are used to detect mold hidden in building structures.
Vulvovaginal yeast infections, gestational diabetes and pregnancy outcome
Background The primary aim was to evaluate the association between gestational diabetes and blood glucose levels and vulvovaginal yeast infections in pregnancy. Secondly, we clarified the possible associations between maternal and prenatal factors, and birth outcomes and yeast infections. Methods Three thousand nine hundred sixty-five pregnant women of the Kuopio Birth Cohort Study (KuBiCo) reported vulvovaginal yeast infections during pregnancy, via electronic questionnaires. Maternal and prenatal data, as well as clinical obstetric and early neonatal outcomes were registered during and after birth. The oral glucose tolerance test was performed on 3,079 women during pregnancy. Logistic regression analysis evaluated the possible multivariable associations between yeast infections, gestational diabetes and other prenatal and maternal factors. Results No association was detected between gestational diabetes or blood glucose levels and vulvovaginal yeast infections during pregnancy. In multivariable analysis, women with yeast infections were more often multiparous, with higher education and had used more often antibiotics during pregnancy compared to others. No significant associations were detected in multivariable analysis between infections, the mode of delivery, preterm birth, birth weight or Apgar scores. Conclusions Women with reported vulvovaginal yeast infections managed generally well during pregnancy. They had no more gestational diabetes or higher blood glucose levels and their newborns managed equally well during early neonatal period.
Associations between dog keeping and indoor dust microbiota
Living with dogs appears to protect against allergic diseases and airway infections, an effect possibly linked with immunomodulation by microbial exposures associated with dogs. The aim of this study was to characterize the influence of dog ownership on house dust microbiota composition. The bacterial and fungal microbiota was characterized with Illumina MiSeq sequencing from floor dust samples collected from homes in a Finnish rural-suburban (LUKAS2, N = 182) birth cohort, and the results were replicated in a German urban (LISA, N = 284) birth cohort. Human associated bacteria variable was created by summing up the relative abundances of five bacterial taxa. Bacterial richness, Shannon index and the relative abundances of seven bacterial genera, mostly within the phyla Proteobacteria and Firmicutes , were significantly higher in the dog than in the non-dog homes, whereas the relative abundance of human associated bacteria was lower. The results were largely replicated in LISA. Fungal microbiota richness and abundance of Leucosporidiella genus were higher in dog homes in LUKAS2 and the latter association replicated in LISA. Our study confirms that dog ownership is reproducibly associated with increased bacterial richness and diversity in house dust and identifies specific dog ownership-associated genera. Dogs appeared to have more limited influence on the fungal than bacterial indoor microbiota.
Risk factors for moisture damage presence and severity in Finnish homes
Moisture-damaged buildings are a prominent issue in Finland, but with limited information on damage prevalence, degree of severity and risk factors. This paper analyses 14,996 Finnish detached and semidetached houses that have undergone a standardised moisture assessment of interior spaces and at-risk structures inside the building envelope. Confirmed damage (a binary indicator of damage presence) and a damage index (an ordinal indicator of severity) were calculated for each home and their association with different building and area characteristics estimated. Frequently damaged structures include pre-1950s log walls, walls contacting soil, wooden ground floors and false plinths. Around 15% of surveyed houses had risk structure damage, 19% had at least one confirmed damage anywhere in the house and 49% had either confirmed, likely or possible damage. The greatest risk factor for confirmed damage was house age (odds ratio = 1.48 (95% confidence interval (CI) = 1.45–1.51) for each decade since construction), with nearly half of all houses built pre-1939 damaged. Other risk factors explained a third of the effect of building age, and included log external walls, fibreboard roofs, absence of mechanical ventilation, detached properties and wind-driven rain precipitation. Results can support targeted remediation efforts, protect health and estimate exposure–response relationships for moisture damage.Practice relevanceMoisture damage in homes causes various health concerns for occupants, and in colder climates such as Finland such damage often occurs within the building structure. This study finds confirmed moisture damage in 19% of surveyed Finnish homes. Most damage was within the building structure, supporting the need for surveys investigating inside known-risk structures. Older homes had much higher damage risk, reflecting different construction methods and ageing, but also suggesting modern building standards are helping to reduce damage. Increased risk in higher wind-driven precipitation regions indicates a need for regulations and research that improve the resilience of all housing to the projected increases in driving rain from climate change. Understanding the building characteristics and structures that increase moisture risk can support targeted remediation and maintenance in vulnerable buildings, conserve older buildings and avoid demolition, and help protect occupant health.
Perinatal factors and high-sensitive C-reactive protein levels during adolescence
Objective To examine whether perinatal factors are associated with low-grade inflammation measured by high-sensitivity C-reactive protein levels during adolescence. Methods Nested case-control study of 125 teenagers who were born by Cesarean delivery and had high-sensitivity C-reactive protein levels determined at 15–17 years. Data on obstetric and perinatal factors were recorded prospectively at the time of their birth. Results Median values of high-sensitivity C-reactive protein were significantly higher in teenagers, who were born as large for gestational age or with maternal diabetes compared to others (2.54 vs 0.34 mg/L; p < 0.024), and born during spring or summer compared to those born during winter or autumn (0.48 vs 0.27 mg/L; p < 0.023). No other perinatal associations were detected (for ex. such as electivity of operation, onset of labor, rupture of fetal membranes, cervical dilatation at delivery, gestational age, Apgar scores at 5 min, umbilical blood pH value, administration of neonatal antibiotics or need of neonatal intensive care treatment) in CRP levels. Further, teenagers with current body mass index in the highest tertile, regular medication for chronic disease and girls using oral contraceptives had significantly higher high-sensitivity C-reactive protein levels than others. Conclusion Prenatal exposures such as maternal metabolic environment and seasonality may have longterm effects on the low-grade inflammation and later cardiometabolic risks. Seasonality might be partly explained by maternal vitamin D levels during pregnancy, and thus future efforts are warranted to ensure sufficient vitamin D availability during pregnancy. Surprisingly, no other significant associations were detected between perinatal characteristics and high-sensitivity C-reactive protein levels.
The Early Development of Wheeze. Environmental Determinants and Genetic Susceptibility at 17q21
Growing up on a farm protects from childhood asthma and early wheeze. Virus-triggered wheeze in infancy predicts asthma in individuals with a genetic asthma risk associated with chromosome 17q21. To test environmental determinants of infections and wheeze in the first year of life, potential modifications of these associations by 17q21, and the implications for different trajectories of wheeze. We followed 983 children in rural areas of Europe from birth until age 6 years. Symptoms of wheeze, rhinitis, fever, and environmental exposures were documented with weekly diaries during year 1. Asthma at age 6 was defined as ever having a reported doctor's diagnosis. Single-nucleotide polymorphisms related to ORMDL3 (rs8076131) and GSDMB (rs7216389, rs2290400) at 17q21 were genotyped. Early wheeze was positively associated with presence of older siblings among carriers of known asthma risk alleles at 17q21 (e.g., rs8076131) (adjusted odds ratio [aOR], 1.53; 95% confidence interval [CI], 1.16-2.01). Exposure to farm animal sheds was inversely related to wheeze (aOR, 0.44; 95% CI, 0.33-0.60). Both effects were similarly observed in children with transient wheeze up to age 3 years without subsequent development of asthma (aOR, 1.71 [95% CI, 1.09-2.67]; and aOR, 0.48 [95% CI, 0.30-0.76], respectively). These findings suggest that the chromosome 17q21 locus relates to episodes of acute airway obstruction common to both transient wheeze and asthma. The previously identified asthma risk alleles are the ones susceptible to environmental influences. Thus, this gene-environment interaction reveals two faces of 17q21: The same genotype constitutes genetic risk and allows for environmental protection, thereby providing options for prospective prevention strategies.
Clinical and Epidemiologic Phenotypes of Childhood Asthma
Clinical and epidemiologic approaches have identified two distinct sets of classifications for asthma and wheeze phenotypes. To compare epidemiologic phenotype definitions identified by latent class analysis (LCA) with clinical phenotypes based on patient histories, diagnostic work-up, and treatment responses. To relate phenotypes to genetic and environmental determinants as well as diagnostic and treatment-related parameters. LCA was performed in an international multicenter birth cohort based on yearly questions about current wheeze until age 6 years. Associations of wheeze classes and clinical phenotypes with asthma-related characteristics such as atopy, lung function, fraction of exhaled nitric oxide, and medication use were calculated using regression models. LCA identified five classes, which verified the clinically defined wheeze phenotypes with high sensitivity and specificity; the respective receiver operating characteristics curves displayed an area under the curve ranging from 84% (frequent wheeze) to 85% (asthma diagnosis) and 87% (unremitting wheeze) to 97% (recurrent unremitting wheeze). Recurrent unremitting wheeze was the most specific and unremitting wheeze at least once the most sensitive definition. The latter identified a subgroup of children with decreased lung function, increased genetic risk, and in utero smoke exposure (ODDS RATIO, 2.03; 95% CONFIDENCE INTERVAL, 1.12-3.68; P = 0.0191), but without established asthma diagnosis and treatment. Clinical phenotypes were well supported by LCA analysis. The hypothesis-free LCA phenotypes were a useful reference for comparing clinical phenotypes. Thereby, we identified children with clinically conspicuous but undiagnosed disease. Because of their high area under the curve values, clinical phenotypes such as (recurrent) unremitting wheeze emerged as promising alternative asthma definitions for epidemiologic studies.
Gut microbiota and overweight in 3-year old children
BackgroundThe gut microbiota has been associated with overweight and obesity in adults, but the evidence in children is limited. Our aim was to study whether composition of the gut microbiota at the age of 3 years is associated with overweight/obesity in children cross-sectionally.MethodsChildren, who participated in a clinical trial of prenatal vitamin-D supplementation (VDAART), underwent standardized height and weight measurements, and collection of stool samples at 3 years of age. 16 S rRNA sequencing (V4 region) of the stool samples were performed with Illumina MiSeq. Associations between microbiota and overweight/obesity (body mass index z-scores >85th percentile) was analyzed using logistic regression.ResultsOut of 502 children, 146 (29%) were categorized as overweight/obese. Maternal pre-pregnancy BMI, birth weight and length, formula feeding during the first year, high frequency of fast food consumption, and time watching TV or computer screen at 3 years were the risk factors for overweight/obesity. Of the top 20 most abundant genera, high relative abundance of Parabacteroidetes (Bacteroidetes; Bacteroidales) (aOR(95% CI): 0.69 (0.53, 0.90, p = 0.007) per interquartile increase) and unassigned genus within Peptostreptococcae family were inversely associated with overweight/obesity, whereas high relative abundance of Dorea (Firmicutes;Clostridiales) (1.23 (1.05, 1.43, p = 0.009)) was positively associated. Associations were independent of each other. No associations were found between diversity indices and overweight/obesity.ConclusionsOur data suggest that some of the differences in gut composition of bacteria between obese and non-obese adults can already be observed in 3-year old children. Longitudinal studies will be needed to determine long-term effects.