The potential prebiotic effect of 2-Butyloctanol on the human axillary microbiome.

OBJECTIVE: The human axilla is colonized by a wide array of microorganisms that contribute to the generation of body odour. Traditional antiperspirant/deodorant products are used to reduce perspiration in the axillary region and to treat or prevent the growth of bacteria in this region, thereby reducing or eliminating body odour. However, they may also compromise the axillary microbiome balance. The personal care industry has been seeking new ingredients, such as prebiotics or probiotics, to maintain a healthy balance of the skin microbiome by inhibiting odour-causing bacteria, whilst maintaining and promoting the growth of good bacteria. The aim of this study was to investigate the prebiotic effect of a skin-care ingredient, 2-butyloctanol, on the human axillary microbiome. METHODS: An in vitro growth inhibition/promotion assay was performed to test whether 2-butyloctanol inhibited or promoted skin bacterial growth. The impact of 2-butyloctanol on the axillary microbiome was also investigated in a human clinical study using 16S rRNA gene sequencing. RESULTS: In-vitro testing showed that 2-butyloctanol significantly inhibited the growth of corynebacteria at concentrations of 0.64%, 2.56% and 5.12%, whilst the growth of Staphylococcus epidermidis was maintained at the same concentrations. The impact of 2-butyloctanol on the axillary microbiome was also validated in a human clinical study. A deodorant roll-on product containing 3% of 2-butyloctanol significantly reduced the relative abundance of corynebacteria, whilst increasing the relative abundance of Staphylococcus and the ratio of Staphylococcus to corynebacteria after four weeks of application, whilst the placebo showed no significant change. CONCLUSION: For the first time, it was demonstrated that 2-butyloctanol had a potential prebiotic effect on the human underarm microbiome in inhibiting odour-causing Corynebacterium, whilst maintaining and promoting skin-friendly Staphylococcus in both in-vitro and in-vivo studies. Therefore, 2-butyloctanol could be used as a potential prebiotic ingredient in personal care products for underarm microbiome protection.

OBJECTIF: les aisselles humaines sont colonisées par un large éventail de micro-organismes qui contribuent à la génération de l'odeur corporelle. Les produits antitranspirants/déodorants traditionnels sont utilisés pour réduire la transpiration et traiter ou prévenir la croissance des bactéries dans la région axillaire, réduisant ou éliminant ainsi l'odeur corporelle. Cependant, ils peuvent également compromettre l'équilibre du microbiome axillaire. Le secteur des soins personnels recherche de nouveaux composants, tels que des prébiotiques ou des probiotiques, afin de maintenir un équilibre sain du microbiome cutané, en inhibant les bactéries responsables des odeurs tout en maintenant et en favorisant la croissance des bonnes bactéries. L'objectif de cette étude était d'étudier l'effet prébiotique sur le microbiome axillaire humain du 2-butyloctanol, un composant indiqué dans les soins cutanés. MÉTHODES: un test in vitro d'inhibition/de promotion de la croissance a été mené afin de déterminer si le 2-butyloctanol inhibait ou favorisait la croissance bactérienne cutanée. Les effets du 2-butyloctanol sur le microbiome axillaire a également fait l'objet d'une étude clinique chez l'homme qui reposait sur le séquençage du gène ARNr 16S. RÉSULTATS: les tests in vitro ont montré que le 2-butyloctanol inhibait significativement la croissance des corynébactéries à des concentrations de 0,64 %, de 2,56 % et de 5,12 %, tandis que la croissance de Staphylococcus epidermidis se maintenait aux mêmes concentrations. Une étude clinique chez l'homme a également permis de confirmer les effets du 2-butyloctanol sur le microbiome axillaire. Un produit déodorant à bille contenant 3 % de 2-butyloctanol a réduit significativement l'abondance relative des corynébactéries, tout en augmentant l'abondance relative de Staphylococcus et le rapport entre Staphylococcus et les corynébactéries après quatre semaines d'application, tandis que le placebo n'a montré aucun changement significatif. CONCLUSION: pour la première fois, des études in vitro et in vivo ont démontré que le 2-butyloctanol avait un possible effet prébiotique sur le microbiome axillaire humain, en inhibant Corynebacterium, la bactérie responsable des odeurs, tout en maintenant et en favorisant la croissance de Staphylococcus, une bactérie respectueuse de la peau. Par conséquent, le 2-butyloctanol pourrait servir de possible composant prébiotique dans les produits de soins personnels pour la protection du microbiome axillaire.

Evaluation of fungal-specific fluorescent labeled echinocandin probes as diagnostic adjuncts.

The diagnosis of invasive fungal infections from radiographic imaging is non-specific and problematic. As a first step toward increasing specificity, we describe the development of a broad-spectrum fungal-specific targeting molecule, which when modified with a fluorescent label fully retains its targeting properties, and provides a basis for future imaging applications.

Simple no-chromatography procedure for amine-reactive Eu3+ luminescent chelates optimal for bioconjugation.

Lanthanide ions luminescence has long life time enabling highly sensitive detection in time-gated mode. The synthesis of reactive lanthanide probes for covalent labeling of the objects of interest is cumbersome task due to the large size of the probes, complex multi-step procedures and the presence of sensitive groups, which often prevents introduction of reactive cross-linking functions optimal for conjugation. We suggest simple synthetic protocol for luminescent europium chelates based on serendipitous reaction yielding acylating compounds, whose reactivity is comparable to that of commonly used N-hydroxysuccinimide (NHS) esters. The probes react with proteins at pH 7.0 within several minutes at ambient temperature displaying high coupling efficiency. The resulting conjugates survive electrophoretic separation under denaturing conditions, which makes the labels useful in proteomic studies that rely on high detection sensitivity.

New cross-linking quinoline and quinolone derivatives for sensitive fluorescent labeling.

A variety of contemporary analytical platforms, utilized in technical and biological applications, take advantage of labeling the objects of interest with fluorescent tracers-compounds that can be easily and sensitively detected. Here we describe the synthesis of new fluorescent quinoline and quinolone compounds, whose light emission can be conveniently tuned by simple structural modifications. Some of these compounds can be used as sensitizers for lanthanide emission in design of highly sensitive luminescent probes. In addition, we also describe simple efficient derivatization reactions that allow introduction of amine- or click-reactive cross-linking groups into the fluorophores. The reactivity of synthesized compounds was confirmed in reactions with low molecular weight nucleophiles, or alkynes, as well as with click-reactive DNA-oligonucleotide containing synthetically introduced alkyne groups. These reactive derivatives can be used for covalent attachment of the fluorophores to various biomolecules of interest including nucleic acids, proteins, living cells and small cellular metabolites. Obtained compounds are characterized using NMR, steady-state fluorescence spectroscopy as well as UV absorption spectroscopy.

Highly bright avidin-based affinity probes carrying multiple lanthanide chelates.

Lanthanide ion luminescence has a long lifetime enabling highly sensitive detection in time-gated mode. The sensitivity can be further increased by using multiple luminescent labels attached to a carrier molecule, which can be conjugated to an object of interest. We found that up to 30 lanthanide chelates can be attached to avidin creating highly bright constructs. These constructs with Eu(3+) chelates display synergistic effect that enhance the brightness of heavily modified samples, while the opposite effect was observed for Tb(3+) chelates thereby significantly reducing their light emission. This undesirable quenching of Tb(3+) luminophores was completely suppressed by the introduction of an aromatic spacer between the chelate and the protein attachment site. The estimated detection limit for the conjugates is in the 10(-14)-10(-15) M range. We demonstrated a high sensitivity for the new probes by using them to label living cells of bacterial and mammalian origin.