Shift in skin microbiota of Western European women across aging.

AIMS: The objective of our study was to compare the microbiota diversity between two different age groups of Western European women. METHODS AND RESULTS: Skin-swab samples were collected directly on the forehead of 34 healthy Western European women: 17 younger (21-31 years old) and 17 older individuals (54-69 years old). Bacterial communities were evaluated using the 16S rRNA gene sequencing. Data revealed a higher alpha diversity on the skin of older individuals compared with younger ones. Overall microbiota structure was different between the two age groups, as demonstrated by beta diversity analysis, which also highlighted a high interpersonal variation within older individuals. Furthermore, taxonomic composition analysis showed both an increase in Proteobacteria and a decrease in Actinobacteria on the older skin. At the genus level, older skin exhibited a significant increase in Corynebacterium and a decrease in Propionibacterium relative abundance. CONCLUSIONS: Our study revealed a shift in the distribution of skin microbiota during chronological aging in Western European women. SIGNIFICANCE AND IMPACT OF STUDY: Altogether these results could become the basis to develop new approaches aiming to rebalance the skin microbiota, which is modified during the aging process.

Polar Lipid Profile of Nannochloropsis oculata Determined Using a Variety of Lipid Extraction Procedures.

Lipid compositions obtained from microalgae species are affected by both the cultivation conditions and the extraction method used. In this study, the extraction of lipids from Nannochloropsis oculata using traditional and modern extraction technologies with several solvents has been compared. Because important polyunsaturated fatty acids are bound to polar lipids, these polar lipids were the main focus of this study. The dominant compounds in the glycolipid fractions were monogalactosyldiglycerides and digalactosyldiglycerides bearing fatty acid chains containing at least one site of unsaturation. Phosphatidylcholine and trimethylhomoserines were detected in the phospholipid fractions. The fatty acid profile comprised large fractions of C16:0, C16:1, C20:5, and C18:3. Extraction of specific compounds was determined by extraction efficiency as well as differences in the selectivity of the method used. The composition derived from a glycolipid fraction was observed to be affected by the method used to a greater extent than the phospholipid fraction.

Thermal degradation of cloudy apple juice phenolic constituents.

Although conventional thermal processing is still the most commonly used preservation technique in cloudy apple juice production, detailed knowledge on phenolic compound degradation during thermal treatment is still limited. To evaluate the extent of thermal degradation as a function of time and temperature, apple juice samples were isothermally treated during 7,200s over a temperature range of 80-145 °C. An untargeted metabolomics approach based on liquid chromatography-high resolution mass spectrometry was developed and applied with the aim to find out the most heat labile phenolic constituents in cloudy apple juice. By the use of a high resolution mass spectrometer, the high degree of in-source fragmentation, the quality of deconvolution and the employed custom-made database, it was possible to achieve a high degree of structural elucidation for the thermolabile phenolic constituents. Procyanidin subclass representatives were discovered as the most heat labile phenolic compounds of cloudy apple juice.

Direct analysis of phthalate ester biomarkers in urine without preconcentration: method validation and monitoring.

Phthalates, which are ubiquitous in the environment, are readily metabolized in human bodies to their respective monoesters. These phthalate monoesters are non-persistent with short half-lives, which make them the ideal biomarkers of human exposure to phthalates. In this study a direct analysis method without preconcentration was developed and validated for the following phthalate ester metabolites in urine: mono-(2-ethylhexyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl)phthalate, monobenzyl phthalate, mono-isobutylphthalate, mono-n-butyl phthalate and monoethyl phthalate. The recovery of the phthalate ester metabolites varied between 97% and 104%. The intraday precision for the replicate analysis (n=10) of a urine sample did not exceed 5% for most of the compounds. The coefficient of variance amounted to 2-3%. The limit of quantification was set equal to 0.5µg/L for the majority of the compounds. A comparison between the direct analysis method and a foregoing solid phase extraction (SPE) of the urine sample was made. Finally, the applicability of the direct analysis method was tested in three interlaboratory comparisons.

An improved mass spectrometric method for identification and quantification of phenolic compounds in apple fruits.

Thirty-nine phenolic compounds were analysed using ultra high performance liquid chromatography (UHPLC) coupled with diode array and accurate mass spectrometry detection using electrospray ionisation (DAD/ESI-am-MS). Instrumental parameters such as scan speed, resolution, and mass accuracy were optimised to establish accurate mass measurements. The method was fully validated in terms of model deviation (r(2)>0.9990), range (typically 10-3500 ngg(-1)), intra/inter-day precision (<6% and <8%, respectively) and accuracy (typically 100 ± 10%). The mass accuracy of each selected phenolic compound was below 1.5 ppm. The results confirmed that the UHPLC-DAD/ESI-am-MS method developed here was convenient and reliable for the determination of phenolic compounds in apple extracts.

Analysis of phthalates in food products and packaging materials sold on the Belgian market.

Phthalates are organic lipophilic compounds that are principally used as plasticiser to increase the flexibility of plastic polymers. Other applications are a.o. the use of phthalates in printing inks and lacquers. Human exposure to phthalates mainly occurs via food ingestion and can induce adverse health effects. In this study, the presence of eight phthalate compounds--dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP) and di-n-octyl phthalate (DnOP)--was investigated in 400 food products, divided over eleven groups, and packages sold on the Belgian market. For this purpose, suitable extraction techniques were developed and validated for four different matrices, namely high-fat foods, low-fat food products, aqueous-based beverages and packaging materials. The instrumental analysis was performed by means of gas chromatography-low resolution-mass spectrometry with electron impact ionisation (GC-EI-MS). A wide variety of phthalate concentrations was observed in the different groups. DEHP was found in the highest concentration in almost every group. Moreover, DEHP was the most abundant phthalate compound, followed by DiBP, DnBP and BBP. This survey is part of the PHTAL project, which is the first project that discusses phthalate contamination on the Belgian food market.