Apple cider vinegar soaks do not alter the skin bacterial microbiome in atopic dermatitis

Abstract

Introduction Atopic dermatitis is a common skin disease characterized by altered cutaneous immunity in which patients often exhibit lower skin microbiota diversity compared to healthy skin and are prone to colonization by Staphylococcus aureus. Apple cider vinegar has been shown to have antibacterial effects; however, its effects on the skin microbiome have not previously been well-described. Objectives We aimed to examine the effects of topical dilute apple cider vinegar soaks on Staphylococcus aureus abundance, skin bacterial microbiome composition, and skin bacterial microbiome diversity in atopic dermatitis participants compared to healthy skin. Methods Eleven subjects with atopic dermatitis and 11 healthy controls were enrolled in this randomized, non-blinded, single-institution, split-arm pilot study. Subjects soaked one forearm in dilute apple cider vinegar (0.5% acetic acid) and the other forearm in tap water for 10 minutes daily. Skin bacteria samples were collected from subjects’ volar forearms before and after 14 days of treatment. 16S sequencing was used to analyze Staphylococcus aureus abundance and skin bacterial microbiome composition, and alpha diversity of microbiota were determined using Shannon diversity index. Results There was no difference in skin bacterial microbiome in atopic dermatitis subjects after 2 weeks of daily water or apple cider vinegar treatments (p = 0.056 and p = 0.22, respectively), or in mean abundance of S. aureus on apple cider vinegar-treated forearms (p = 0.60). At 2 weeks, the skin bacterial microbiomes of healthy control subjects were not significantly different from the skin bacterial microbiome of atopic dermatitis subjects (p = 0.14, 0.21, 0.12, and 0.05). Conclusions Our results suggest that daily soaks in 0.5% apple cider vinegar are not an effective method of altering the skin bacterial microbiome in atopic dermatitis. Further studies are needed to explore the effects of different concentrations of apple cider vinegar on skin microflora and disease severity. Trial number UVA IRB-HSR #19906.

Bathing in Atopic Dermatitis in Pediatric Age: Why, How and When

“…However, a study examined the effects on Staphylococcus aureus abundance after 14 days of topical dilute apple cider vinegar (0.5% acetic acid) in 11 subjects with AD compared with 11 healthy controls. The results suggested no difference in the mean abundance of S. aureus in AD subjects and no significant differences in the skin bacterial microbiome of healthy control subjects [ 88 ]. Another recent study showed that diluted apple cider vinegar did not affect skin barrier integrity but caused skin irritation in most subjects [ 89 ].…”

The role of short-chain fatty acids in inflammatory skin diseases

“…Local application of SCFAs can promote the growth of beneficial microbes, and topical administration of probiotics promotes the release of SCFAs to mitigate skin inflammation ( Kim C. H. et al, 2015 ). In a trial to validate acetate for AD, topical application of apple cider vinegar (0.5% acetate) for 2 weeks did not affect the skin microbiome of healthy subjects and AD patients compared to the water placebo group, and also did not prevent the colonization of S. aureus on the inflamed skin ( Luu et al, 2021 ). However, no significant difference was observed in the diversity of the skin microbiome between the AD patients and healthy subjects at baseline ( Luu et al, 2021 ).…”

“…In a trial to validate acetate for AD, topical application of apple cider vinegar (0.5% acetate) for 2 weeks did not affect the skin microbiome of healthy subjects and AD patients compared to the water placebo group, and also did not prevent the colonization of S. aureus on the inflamed skin ( Luu et al, 2021 ). However, no significant difference was observed in the diversity of the skin microbiome between the AD patients and healthy subjects at baseline ( Luu et al, 2021 ). Therefore, the inhibitory effect of apple cider vinegar on S. aureus growth may depend on the bacterial strain and the levels of acetate ( Fraise et al, 2013 ).…”

From gut to skin: exploring the potential of natural products targeting microorganisms for atopic dermatitis treatment

“…216 We found in the review that daily soaks in 0.5% apple cider vinegar do not work on altering the bacterial microbes of the skin in AD. 217 Dilute apple cider vinegar soaks have no significant effect on skin barrier integrity; however, they do not cause skin irritation in most subjects. 218 The existing data cannot support this argument.…”