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Bacteria are involved in the onset and progression of periodontitis. A promising molecular technique, denaturing gradient gel electrophoresis (DGGE), to study microbial population dynamics in the subgingival pocket is presented. Twenty-three samples were taken from the subgingival pockets of nine patients and six healthy family members. From four periodontitis patients, 12 samples were evaluated before, 1 day after and 3 months after treatment. Part of the 16S rRNA gene of all bacteria was amplified by PCR and separated by DGGE, creating banding patterns representative of the community structure. Shifts in composition and diversity of the microbial population could be determined semiquantitatively, and this showed that treatment resulted in a decrease in the diversity of the population. After 3 months a microbial population 33–47% different from the population before treatment had re-established. Intense bands representing Exiguobacterium aurantiacum were present in 13 out of 25 samples, indicating that this species may play a role in periodontal disease. [ABSTRACT FROM AUTHOR]

Climate change threatens many well‐preserved archaeological sites in the Arctic. The paper presents the first Arctic multi‐threat assessment focusing on the Nuuk region of Greenland. The results suggest that the majority of the 336 known archaeological sites are already exposed to impacts from microbial degradation, permafrost thaw and vegetation, and that these impacts will increase over the next 80 years. Additional impacts from coastal erosion are only noted at a limited number of sites due to a predominant consolidated and uplifting coast. The applied methods represent an important first step to identify threatened sites and emphasize important data limitations. [ABSTRACT FROM AUTHOR]

Background Gut microbiota and intestinal inflammation regulate the development of immune-mediated diseases, such as allergies. Fecal calprotectin is a biomarker of intestinal inflammation. Objective We evaluated the association of early-age fecal calprotectin levels to the later development of allergic diseases in children from farming and non-farming environments and further studied the effect of gut microbiota on the fecal calprotectin levels. Methods Fecal calprotectin was measured from 758 infants participating in the PASTURE study at the age of 2 months using the ELISA method. Serum-specific IgE levels were measured at 6 years of age. Data of environmental factors, doctor-diagnosed atopic dermatitis ( AD) and asthma were collected by questionnaire. Multivariate logistic regression models were used for analysis. The composition of fecal microbiota was analysed in a subgroup of 120 infants with 16S rRNA pyrosequencing. The effect of Escherichia coli lipopolysaccharide ( LPS) on in vitro monocyte IL-10 secretion was studied by flow cytometry. Results The infants with high fecal calprotectin levels at 2 months, that is above the 90th percentile, had an increased risk of developing AD and asthma/asthmatic bronchitis by the age of 6 years ( aOR 2.02 (1.06-3.85) and 2.41 (1.25-4.64), respectively). High fecal calprotectin levels correlated negatively with fecal Escherichia. LPS from E. coli stimulated production of IL-10 in monocytes. Conclusion and Clinical Relevance High degree intestinal inflammation at 2 months of age, detected as high fecal calprotectin, predicted asthma and AD by the age of 6 years and was linked to low abundance of fecal Escherichia. Impaired IL-10 activation due to the lack of colonization with E. coli could explain the intestinal inflammation associated high fecal calprotectin and later risk of asthma and AD. Our results have implications for the design of probiotic treatments and suggest that early intestinal colonization has long-term health effects. [ABSTRACT FROM AUTHOR]

It has been suggested that intestinal microbiota of allergic and non-allergic children differs in composition, and that microbiota–immune system interactions may predispose children to develop sensitization. Previous studies have examined fecal microbiota of allergic children with atopic dermatitis, but little is known about that of atopic wheezy children. To investigate the composition of the fecal microbiota of young sensitized wheezy and non-sensitized non-wheezy children, using molecular methods. Within the context of a prospective birth cohort, we carried out a nested case–control study of sensitized wheezy children (cases) and non-sensitized non-wheezy controls. Cases and controls were matched for age, sex, parental atopy, allergen exposure, and pet ownership. We evaluated the composition of fecal microbiota by nucleic acid-based methods (PCR combined with denaturing gradient gel electrophoresis and quantification of bifidobacteria by fluorescent in situ hybridization). Thirty-three case–control pairs (mean age 4.4 years) provided stool samples. Comparison of total bacterial community profiles showed that each child had a unique fecal microbiota (mean Dice's similarity coefficient 22%, range 3.3–60.8%). There was no difference between the groups in prevalence of Lactic Acid bacteria (12/33 vs. 11/33, P=0.8) or bifidobacteria (30/33 vs. 31/33, P=1.00, cases vs. controls). The bifidobacterial species detected were similar in both groups. The percentage of bifidobacteria in total fecal microflora was no different between cases (median 1.7%, range 0–20.8%) and controls (1.9%, 0–18.2%, P=0.7). However, cases with eczema had significantly fewer bifidobacteria (median 1.6%, range 0–4.8%) than their controls (4.0%, 1.9–18.2%, P=0.05). We found no differences in fecal microbiota composition between sensitized wheezy and non-sensitized, non-wheezy children aged 3–5 years using nucleic acid-based methods. Differences appear to be isolated to those allergic children with eczema. [ABSTRACT FROM AUTHOR]