Lotion Containing Fermented Honey and Chamomile Liquid Improves Facial Skin Hydration: A Double-Blind, Split-Face, Placebo-Controlled Clinical Trial

This study evaluated the effects of a lotion containing honey and chamomile fermented with Apilactobacillus kunkeei (A. kunkeei) YB38 on facial skin in healthy Japanese adults. Honey and chamomile extracts (EHC) were fermented with A. kunkeei YB38 to prepare fermented honey and chamomile extract (FHC). To confirm that FHC was fermented, component analysis was performed by HPLC and compared with EHC. Healthy Japanese adults (n = 35) were administered a lotion containing FHC (FHC-Lo) and a placebo lotion (PLBO-Lo) for four weeks in a placebo-controlled, double-blind, split-face trial. Stratum corneum (SC) water content, transepidermal water loss, and skin elasticity were measured before and after application. The presence of lactic and acetic acids indicated FHC fermentation. Applying FHC-Lo for 4 weeks significantly increased SC water content compared to PLBO-Lo (FHC-Lo: from 31.22 ± 1.47 to 37.4 ± 4.68 AU vs. PLBO-Lo: from 31.10 ± 1.52 to 32.4 ± 3.73 AU, p = 5.90 × 10−6), with no adverse events observed. This mechanism might involve the action of lactic acid increased by fermentation.