Acta Dermato-Venereologica 98-8CompleteContent | Page 16

783 INVESTIGATIVE REPORT Patients with Acne Vulgaris Have a Distinct Gut Microbiota in Comparison with Healthy Controls Yongqiong DENG 1# , Hong WANG 1# , Jiyuan ZHOU 3 , Yunzhu MOU 4 , Guiqiang WANG 2 and Xia XIONG 1 1 Department of Dermatology & STD, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, 2 Department of Infectious Disease, Peking University First Hospital, Beijing, 3 Biomedical Research Institute, Shenzhen Peking University, The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong Province, 4 Department of Dermatology & STD, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, China # These authors contributed equally to this article. Acne vulgaris has been postulated to have a gastroin- testinal mechanism; however, little is known about gut microbiota dysfunction in this condition. The aim of this cross-sectional study was to investigate whether the gut microbiota is altered in acne. Faecal bacterial diversity was analysed in 43 patients with acne and 43 controls, using hypervariable tag sequencing of the V3–V4 region of the 16S rDNA gene. Distinct diffe- rences were found in microbial diversity between pa- tients with acne and controls (Shannon diversity index (p  = 0.009) and Simpson diversity index (p  = 0.01)). At the phylum level, the abundance of Firmicutes was lo- wer in the patient group, but that of Bacteroidiain was higher. The most significantly depleted taxa in acne were Clostridia, Clostridiales, Lachnospiraceae and Ruminococcaceae genera, which are potentially bene- ficial. In conclusion, patients with acne vulgaris have gut microbial dysbiosis; further study is needed to un- derstand its role in the pathogenesis of acne. Key words: acne vulgaris; gut microbiota; bacterial diversity. Accepted May 9, 2018; Epub ahead of print May 14, 2018 Acta Derm Venereol 2018; 98: 783–790. Corr: Guiqiang Wang, Department of Infectious Disease, Peking Univer- sity First Hospital, No.8 Xishiku Street, Xicheng District, Beijing, China. E-mail: [email protected]; and Xia Xiong, Department of Dermato- logy & STD, the Affiliated Hospital of Southwest Medical University, No. 25 Taiping Street, Luzhou, Sichuan, China. E-mail: [email protected] A cne vulgaris is a chronic inflammatory skin disease of the pilosebaceous units that is e stimated to af- fect up to 80–90% of adolescent patients, particularly in developed nations (1). In general, the pathogenesis of acne is characterized by increased production of se- bum, inflammatory mediators in the skin, and follicular hyperkeratinisation of pilosebaceous ducts. The role of Propionibacterium acnes is not clear, as this organism is ubiquitous in healthy adult human skin. However, an altered phenotype of P. acnes in acne lesions may be more associated with the disease and may also be pro- inflammatory (2, 3). Although genetic predisposition can strongly influence the risk of developing acne, the role of environmental factors, especially the “Western style” diet, in the pathogenesis of acne has been sug- gested (4, 5). The “Western style” diet includes milk, other dairy products, refined carbohydrates, chocolate, SIGNIFICANCE This study presents the difference of gut microbes between acne vulgaris patients and healthy controls. Comparing with healthy controls, acne patients show the decreased diversity of gut microbiota and the increased ratio of Bac- teroidetes to Firmicutes which has been reported to be the enterotype of the Western diet. These data validate the role of western diet in promoting the development of acne vulgaris and suggest the diet and probiotic-based therapy in preventing and treating acne vulgaris. and saturated fats, which contribute to the formation of acne by activating nutrient-derived metabolic signals (6, 7). Dietary supplementation with omega-3 fatty acids has been reported to help decrease lesions in patients with mild to moderate acne (8). The ratio of omega-6 to omega-3 fatty acids is higher in “Western style” than in non-Western diets (9). Accumulating evidence indicates that the gut mi- crobiota associated with the “Western style” diet play a significant role in the development of a number of disease states, such as immune, metabolic, and even skin, diseases (10–12). High-fat diets have been repor- ted to reduce the levels of gut microbes and increase the concentration of lipopolysaccharides (LPS), which contribute to the development of systemic inflammation by impairing colonic epithelial integrity and barrier func­ tion, decreasing mucus layer thickness and increasing the secretion of pro-inflammatory cytokines (13–15). However, there is no direct evidence that imbalance of gut microbiota contributes to the pathogenesis of acne vulgaris. It can be postulated that acne vulgaris features a gastrointestinal mechanism based on the theory of microbiota-gut-brain axis (16). The latest research has shown that communication between the gut and brain plays a critical role in maintaining optimal health, and that changes in gut microbiota may affect central nervous system function and neuroendocrine respon- ses, such as the hypothalamus pituitary adrenal axis (HAP) (16–18). HAP modulates most of a number of pathways and hormones implicated in the pathogenesis of acne, such as androgens, insulin-like growth factor, corticotrophin-releasing hormone, ectopeptidases, adre- This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica. doi: 10.2340/00015555-2968 Acta Derm Venereol 2018; 98: 783–790