Potential Role of the Microbiome in Acne: A Comprehensive Review

Abstract

Acne is a highly prevalent inflammatory skin condition involving sebaceous sties. Although it clearly develops from an interplay of multiple factors, the exact cause of acne remains elusive. It is increasingly believed that the interaction between skin microbes and host immunity plays an important role in this disease, with perturbed microbial composition and activity found in acne patients. Cutibacterium acnes (C. acnes; formerly called Propionibacterium acnes) is commonly found in sebum-rich areas and its over-proliferation has long been thought to contribute to the disease. However, information provided by advanced metagenomic sequencing has indicated that the cutaneous microbiota in acne patients and acne-free individuals differ at the virulent-specific lineage level. Acne also has close connections with the gastrointestinal tract, and many argue that the gut microbiota could be involved in the pathogenic process of acne. The emotions of stress (e.g., depression and anxiety), for instance, have been hypothesized to aggravate acne by altering the gut microbiota and increasing intestinal permeability, potentially contributing to skin inflammation. Over the years, an expanding body of research has highlighted the presence of a gut–brain–skin axis that connects gut microbes, oral probiotics, and diet, currently an area of intense scrutiny, to acne severity. This review concentrates on the skin and gut microbes in acne, the role that the gut–brain–skin axis plays in the immunobiology of acne, and newly emerging microbiome-based therapies that can be applied to treat acne.

Characterization and Analysis of the Skin Microbiota in Acne: Impact of Systemic Antibiotics

“…The role of the skin microbiome in acne is of great interest to clinicians, patients, and researchers. This interest originates in part from the long-established view that C. acnes has a causative role in acne pathogenesis [2,17] and the efficacy of oral and topical antibiotics in acne treatment. Our longitudinal cohort study examined the skin microbiota of untreated acne skin and the influence of systemic antibiotics on acne skin microbiota.…”

“…As for acne severity, the prevalence of C. acnes correlated with the severity of acne, which suggests that it is at the center of the disease process. Several mechanisms have been suggested by which C. acnes aggravates acne, including comedone formation, augmentation of lipogenesis, and host inflammation [2,17].…”

“…Colonization and triggering by Cutibacterium acnes (C. acnes; formerly called Propionibacterium acnes), a regular occupant of human skin and sebaceous follicles, has also been linked with acne through its impact on lipogenesis, comedone formation, and host inflammation [1,2]. The skin harbors hundreds of microorganisms, and it is highly likely that the overall balance of the bacteria on a person's skin is as critical as C. acnes in acne development and skin health.…”

Caenorhabditis elegansmounts a p38MAPKpathway‐mediated defence toCutibacterium acnesinfection

“…The Gram‐positive, anaerobic, slow‐growing bacterium Cutibacterium acnes (formerly Propionibacterium acnes ) is responsible for recrudescent or chronic acne, and can also affect implants, such as cardiovascular devices and prosthetic joints (Achermann, Goldstein, Coenye, & Shirtliff, 2014; Lee, Byun, & Kim, 2019). More than 50% of C. acnes isolates are resistant to topical macrolides, making treatment challenging (Leheste et al, 2017; Portillo, Corvec, Borens, & Trampuz, 2013; Van Boeckel et al, 2014).…”

The Skin Microbiota and Itch: Is There a Link?

“…The gut and skin are uniquely related in function, and numerous studies link gut microbiota to skin homeostasis (skin-gut axis or skin-gut-brain axis) [35,[161][162][163][164]. Commonalities have also been found between itch transition in the skin and neural signaling in the lower intestinal tract, which raises the possibility of intestinal microbiota playing a role in itching [165,166].…”