MATERIALS AND METHODS: Given that an array of active ingredients and topical vehicles for moisturisers are available in the market, this review summarised the roles of ceramides and multivesicular emulsion (MVE) technology in managing AD to help guide treatment decisions.
RESULTS: Ceramides are essential in maintaining the skin permeability barrier and hydration, modulating skin immunity through anti-inflammatory and antimicrobial defence system, and regulating cellular functions. Low levels and altered structures and composition of ceramides, compromised skin permeability barrier and increased transepidermal water loss were commonly observed in AD patients. Most clinical studies have shown that ceramidedominant moisturisers are safe and effective in adults and children with AD. MVE technology offers an attractive delivery system to replenish ceramides in the SC, repairing the compromised skin permeability barrier and potentially improving patient compliance.
CONCLUSION: Recommending clinically proven therapeutic moisturisers with the right ingredients (level, ratio, structure and composition), alongside an effective sustained release delivery system, to AD patients is one key strategy to successful disease control and flare prevention, subsequently reducing the disease burden to patients, families and societies.
METHODS: Two hundred subjects (104 patients, 96 controls) underwent extensive clinical phenotyping. Stool samples were analyzed using 16S rRNA gene sequencing. Fecal metabolomics were performed using two platforms, nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry.
RESULTS: Fecal microbiome and metabolome composition in PD was significantly different from controls, with the largest effect size seen in NMR-based metabolome. Microbiome and NMR-based metabolome compositional differences remained significant after comprehensive confounder analyses. Differentially abundant fecal metabolite features and predicted functional changes in PD versus controls included bioactive molecules with putative neuroprotective effects (eg, short chain fatty acids [SCFAs], ubiquinones, and salicylate) and other compounds increasingly implicated in neurodegeneration (eg, ceramides, sphingosine, and trimethylamine N-oxide). In the PD group, cognitive impairment, low body mass index (BMI), frailty, constipation, and low physical activity were associated with fecal metabolome compositional differences. Notably, low SCFAs in PD were significantly associated with poorer cognition and low BMI. Lower butyrate levels correlated with worse postural instability-gait disorder scores.
INTERPRETATION: Gut microbial function is altered in PD, characterized by differentially abundant metabolic features that provide important biological insights into gut-brain pathophysiology. Their clinical relevance further supports a role for microbial metabolites as potential targets for the development of new biomarkers and therapies in PD. ANN NEUROL 2021;89:546-559.