Emollient use alters skin barrier and microbes in infants at risk for developing atopic dermatitisOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study asked how regular skin emollient use changes the skin barrier and skin bacteria in infants at risk for atopic dermatitis (AD). It was a randomized controlled trial with 16S rRNA gene sequencing. Infants were randomized near birth to daily whole-body emollient (Cetaphil Moisturizing Cream) or no routine emollient for six months. At six months, skin pH, transepidermal water loss and water capacitance were measured. Swabs from cheek and forearms were sequenced (V1-V3 region) on a 454 platform.
Who was studied?
The cohort was 23 newborns with a family history of atopy, randomized to emollient (n = 11) or control (n = 12), enrolled at Oregon Health and Science University, USA. All had a first-degree relative with AD, asthma or allergic rhinitis. Preterm birth and antibiotic use were exclusion criteria. To avoid confounding by active disease, diversity analyses focused on infants who did not develop AD (emollient n = 10, control n = 9). In total 114 samples yielded 643,999 high-quality reads.
What were the most important findings?
Emollient use lowered skin pH significantly versus controls (p = 0.02). It also raised bacterial richness (Chao index) at all sites (cheek p = 0.002, dorsal forearm p = 0.009, volar forearm p = 0.005). Streptococcus salivarius was significantly more abundant in the emollient group at every site (p = 0.02). The S. mitis group and S. salivarius drove community differences between groups. S. salivarius appeared lower in infants who developed AD, and in a separate cohort of older children its proportion fell during AD flares, an inverse link to disease severity.
What are the greatest implications of this study?
The results suggest emollients may help prevent AD partly by acidifying the skin and favoring commensals like Streptococcus salivarius, which has immunomodulatory, anti-inflammatory properties. A more diverse, S. salivarius-rich community resembled healthier skin. This offers a possible microbial mechanism for emollients as an AD preventative in high-risk infants. The trial was small (about 10 per group), and only a few infants developed AD, limiting statistical power. The AD associations were not significant on their own, so larger studies are needed to confirm them.