Profiling the Effects of Systemic Antibiotics for Acne, Including the Narrow-Spectrum Antibiotic Sarecycline, on the Human Gut Microbiota

Sarecycline for moderate to severe acne: a promising narrow-spectrum antibacterial drug

Sarecycline, a narrow-spectrum antibacterial drug approved by the FDA in 2018, targets Cutibacterium acnes while potentially minimizing disruption to the gut microbiota. The aim of this study is to assess the efficacy and safety of sarecycline compared to placebo in treating moderate to severe facial acne. A comprehensive search of PubMed, MEDLINE, and Cochrane databases was performed, with data extraction and screening conducted independently by two authors. Statistical analysis used RevMan, and the risk of bias was evaluated using RoB 2. Three RCTs (n = 2287 patients, mean age 19.6-20.8 years) met the inclusion criteria. Sarecycline (1.5 mg/kg) administered daily for 12 weeks significantly reduced inflammatory and non-inflammatory lesion counts compared to placebo (p < 0.00001). Other outcomes were not statistically significant. Sarecycline 1.5 mg/kg daily is an effective and well-tolerated treatment for moderate to severe acne with minimal side effects.

Emerging Treatments for Persistent Corneal Epithelial Defects

Persistent corneal epithelial defects (PCEDs) are a challenging ocular condition characterized by the failure of complete corneal epithelial healing after an insult or injury, even after 14 days of standard care. There is a lack of therapeutics that target this condition and encourage re-epithelialization of the corneal surface in a timely and efficient manner. This review aims to provide an overview of current standards of management for PCEDs, highlighting novel, emerging treatments in this field. While many of the current non-surgical treatments aim to provide lubrication and mechanical support, novel non-surgical approaches are undergoing development to harness the proliferative and healing properties of human mesenchymal stem cells, platelets, lufepirsen, hyaluronic acid, thymosin ß4, p-derived peptide, and insulin-like growth factor for the treatment of PCEDs. Novel surgical treatments focus on corneal neurotization and limbal cell reconstruction using novel scaffold materials and cell-sources. This review provides insights into future PCED treatments that build upon current management guidelines.

Using nutrition to help recovery from infections

PURPOSE OF REVIEW

Antibiotics are a cornerstone of modern medicine, but antibiotic consumption can have depleting effects on the gut microbiota, potentially leading to gastrointestinal symptoms and other diseases, namely Clostridioides difficile infection. Because nutrition is a major driver of gut microbiota diversity and function, here we explore the current evidence on the potential of diets in alleviate the deleterious effects of antibiotics consumed during infections.

RECENT FINDINGS

Beneficial nutrients can enhance the symbiotic effect of the gut microbiota with the host, supporting anti-inflammatory responses and maintaining tight junction integrity. Short-chain fatty acids have been shown to positively affect the immune response, reducing the severity of C. difficile infection, whereas high-fibre diets have been shown to promote faster recovery of the gut microbiota after antibiotic therapy.

SUMMARY

The role of nutrition during infection is gaining momentum, with key findings exploring the effect of some nutrients in limiting the severity of infections and helping the microbiota recover from antibiotic-induced dysbiosis. Although this field is in its infancy, these findings open the possibility of personalised nutrition as a way of restoring microbiome diversity. But more work is needed to identify the most effective types and combinations of nutrients to achieve this.

Doxycycline Post-Exposure Prophylaxis for Bacterial Sexually Transmitted Infections: The Current Landscape and Future Directions

PURPOSE OF REVIEW

The incidence of bacterial sexually transmitted infections (STI) continues to rise particularly among men who have sex with men (MSM). Doxycycline post-exposure prophylaxis (doxy-PEP) has emerged as a promising biomedical prevention strategy. This review aims to summarize the results of recent studies, highlight the current normative guidance on the use of doxy-PEP, and discuss remaining questions.

RECENT FINDINGS

In the past decade, there have been four randomized controlled trials and three real-world analyses of doxy-PEP, which consistently demonstrated a reduction in Chlamydia trachomatis and Treponema pallidum infections among MSM. Questions remain regarding the efficacy of doxy-PEP for Neisseria gonorrhoeae infection and among cisgender women. Possible detrimental impacts include an increase in antimicrobial resistance as well as alterations to the gut microbiome Doxy-PEP is an effective strategy for preventing Chlamydia trachomatis and Treponema pallidum among MSM. Further work is needed to investigate the benefits among other populations, as well as to monitor for adverse effects.

The Role of the Skin Microbiome in Acne: Challenges and Future Therapeutic Opportunities

Acne vulgaris is a widespread dermatological condition that significantly affects the quality of life of adolescents and adults. Traditionally, acne pathogenesis has been linked to factors such as excess sebum production, follicular hyperkeratinization, and the presence of Cutibacterium acnes (C. acnes). However, recent studies have highlighted the role of the skin microbiome, shifting focus from individual pathogens to microbial community dynamics. This review critically evaluates existing research on the skin microbiome and its relationship to acne, focusing on microbial diversity, C. acnes strain variability, and emerging therapies targeting the microbiome. While certain studies associate C. acnes with acne severity, others show this bacterium's presence in healthy skin, suggesting that strain-specific differences and overall microbial balance play crucial roles. Emerging therapeutic approaches, such as probiotics and bacteriophage therapy, aim to restore microbial equilibrium or selectively target pathogenic strains without disturbing the broader microbiome. However, the lack of standardized methodologies, limited longitudinal studies, and the narrow focus on bacterial communities are major limitations in current research. Future research should explore the broader skin microbiome, including fungi and viruses, use consistent methodologies, and focus on longitudinal studies to better understand microbial fluctuations over time. Addressing these gaps will enable the development of more effective microbiome-based treatments for acne. In conclusion, while microbiome-targeted therapies hold promise, further investigation is needed to validate their efficacy and safety, paving the way for innovative, personalized acne management strategies.

Tetracyclines Revisited: Tetracyclines in the Field of Dermatology

BACKGROUND

Tetracyclines are a class of broad-spectrum antibiotics favored by dermatologists. Over the last decade, the clinical efficacy of tetracyclines has expanded into various dermatoses.

SUMMARY

This review tries to encompass the possible indications of tetracycline in the field of dermatology and possible mechanisms of action. This comprehensive review encompasses all possible indications of tetracyclines besides acne vulgaris and rosacea: hidradenitis suppurativa, autoimmune bullous dermatoses, vitiligo, alopecia, prurigo pigmentosa, granulomatous dermatoses, Kaposi's sarcoma, cold urticaria, atopic dermatitis, scrub typhus, scarring, and miscellaneous dermatoses. We also focus on the recently approved sarecycline, a third-generation narrow-spectrum tetracycline, and its clinical efficacy and potential impact on the microbiome. Our review provides a better understanding of this extremely familiar drug class and encourages its use in a wider spectrum of dermatologic diseases and symptoms.

KEY MESSAGES

This study comprehensively reviewed the current literature on potential indications of tetracyclines in the field of dermatology.

Alterations in the Skin Microbiome in Dermatologic Diseases and with External Exposures: CME Part 2

In Part I of our CME we reviewed the skin microbiome in healthy individuals. Part II reviews the evolving understanding of alterations in the skin microbiome in specific human diseases. We also discuss how the skin microbiome can change with environmental exposures and medications such as antibiotics as well as ongoing research on microbiome-based interventions.

Four recent insights suggest the need for more refined methods to assess the resistogenicity of doxycycline post exposure prophylaxis

Two recently published randomized trials of doxycycline post exposure prophylaxis (PEP) have concluded that this intervention is highly effective at reducing the incidence of bacterial sexually transmitted infections (STIs) and has little or no risk of promoting the spread of antimicrobial resistance (AMR). In this perspective piece, we review four types of evidence that suggest that the risk of promoting AMR has been inadequately assessed in these studies. 1) The studies have all used proportion resistant as the outcome measure. This is a less sensitive measure of resistogenicity than MIC distribution. 2) These RCTs have not considered population-level pathways of AMR selection. 3) In populations with very high antimicrobial consumption such as PrEP cohorts, the relationship between antimicrobial consumption and resistance may be saturated. 4) Genetic linkage of AMR means that increased tetracycline use may select for AMR to not only tetracyclines but also other antimicrobials in STIs and other bacterial species. We recommend novel study designs to more adequately assess the AMR-inducing risk of doxycycline PEP.

Intestinal Microbiota Dysbiosis Promotes Mucosal Barrier Damage and Immune Injury in HIV-Infected Patients

The intestinal microbiota is an "invisible organ" in the human body, with diverse components and complex interactions. Homeostasis of the intestinal microbiota plays a pivotal role in maintaining the normal physiological process and regulating immune homeostasis. By reviewing more than one hundred related studies concerning HIV infection and intestinal microbiota from 2011 to 2023, we found that human immunodeficiency virus (HIV) infection can induce intestinal microbiota dysbiosis, which not only worsens clinical symptoms but also promotes the occurrence of post-sequelae symptoms and comorbidities. In the early stage of HIV infection, the intestinal mucosal barrier is damaged and a persistent inflammatory response is induced. Mucosal barrier damage and immune injury play a pivotal role in promoting the post-sequelae symptoms caused by HIV infection. This review summarizes the relationship between dysbiosis of the intestinal microbiota and mucosal barrier damage during HIV infection and discusses the potential mechanisms of intestinal barrier damage induced by intestinal microbiota dysbiosis and inflammation. Exploring these molecular mechanisms might provide new ideas to improve the efficacy of HIV treatment and reduce the incidence of post-sequelae symptoms.

Bidirectional Interaction between Tetracyclines and Gut Microbiome

The escalating misuse of antibiotics, particularly broad-spectrum antibiotics, has emerged as a pivotal driver of drug resistance. Among these agents, tetracyclines are widely prescribed for bacterial infections, but their indiscriminate use can profoundly alter the gut microbiome, potentially compromising both their effectiveness and safety. This review delves into the intricate and dynamic interplay between tetracyclines and the gut microbiome, shedding light on their reciprocal influence. By exploring the effects of tetracyclines on the gut microbiome and the impact of gut microbiota on tetracycline therapy, we seek to gain deeper insights into this complex relationship, ultimately guiding strategies for preserving antibiotic efficacy and mitigating resistance development.

Curcumin/Fusidic Acid Bitherapy Loaded Mixed Micellar Nanogel for Acne Vulgaris Treatment: In Vitro and In Vivo Studies

The combination of herbal drugs with a topical antibacterial for managing a chronic disease like acne vulgaris has emerged lately to settle side effects and bacterial multidrug resistance. Mixed micelles (MMs) incorporated into nanogel were explored for hybrid delivery of curcumin (Cur) and fusidic acid (FA) combination presenting a multi-strategic treatment. Curcumin-fusidic acid-loaded mixed micelles (Cur-FA-MMs) were assessed for size, surface charge, compatibility, in vitro release, and encapsulation. The selected formula was further loaded into nanogel and investigated for viscosity, ex vivo permeation, and in vivo potential. Cur-FA-MMs exhibited uniform nanosized spherical morphology, and negative surface charge affording high encapsulation for both drugs with a biphasic in vitro release over a period of 48h and good colloidal stability. The attained Cur-FA-MM-loaded nanogel had optimum viscosity with remarkable permeation coefficient values nearly 2-fold that related to plain nanogel. The pharmacodynamic effect of Cur on FA was pronounced by the significant improvement of the skin's degree of inflammation, epidermal hypertrophy, and congestion in animals treated with Cur-FA-MM-loaded nanogel. In conclusion, micellar nanogel could enable the progressive effect of Cur (an antioxidant with reported antibiotic activity) on FA (antibiotic) and decrease the risk of emerging antibiotic resistance by enhancing the solubility and permeation of Cur.

Prolonged Antibiotic Exposure during Adolescence Dysregulates Liver Metabolism and Promotes Adiposity in Mice

Antibiotic administration during early life has been shown to have lasting effects on the gut microbiota, which have been linked to sustained alterations in liver metabolism and adiposity. Recent investigations have discerned that the gut microbiota continues to develop toward an adult-like profile during adolescence. However, the impact of antibiotic exposure during adolescence on metabolism and adiposity is unclear. Herein, a retrospective analysis of Medicaid claims data was performed, which indicated that tetracycline class antibiotics are commonly prescribed for the systemic treatment of adolescent acne. The purpose of this was to discern the impact of a prolonged tetracycline antibiotic exposure during adolescence on the gut microbiota, liver metabolism, and adiposity. Male C57BL/6T specific pathogen-free mice were administered a tetracycline antibiotic during the pubertal/postpubertal adolescent growth phase. Groups were euthanized at different time points to assess immediate and sustained antibiotic treatment effects. Antibiotic exposure during adolescence caused lasting genera-level shifts in the intestinal bacteriome and persistent dysregulation of metabolic pathways in the liver. Dysregulated hepatic metabolism was linked to sustained disruption of the intestinal farnesoid X receptor-fibroblast growth factor 15 axis, a gut-liver endocrine axis that supports metabolic homeostasis. Antibiotic exposure during adolescence increased subcutaneous, visceral, and marrow adiposity, which intriguingly manifested following antibiotic therapy. This preclinical work highlights that prolonged antibiotic courses for the clinical treatment of adolescent acne may have unintended deleterious effects on liver metabolism and adiposity.

A Post Hoc Analysis of Efficacy Data on Sarecycline in Hispanics with Acne from Two Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Trials

Sarecycline is a novel, narrow-spectrum, third generation tetracycline class antibiotic approved by the Food and Drug Administration (FDA) for the treatment of moderate-to-severe acne in patients ages nine and older. Recently, focus has increased on whether treatment responses differ in acne in skin of color. Here, we aimed to analyze the efficacy of using sarecycline in Hispanics. We report pooled post hoc analysis of efficacy data on sarecycline in Hispanics with acne from two phase 3, multicenter, randomized, double-blind, placebo-controlled clinical trials, SC1401 and SC1402. Of 2002 patients in the pooled trials with moderate-to-severe acne, 26.9% were Hispanic. Facial inflammatory lesion counts decreased as early as week 3 by 26% (p = 0.0279), with continued reduction by 41% by week 6 (p = 0.0003), by 51% by week 9 (p < 0.0001), and by 55% by week 12 (p < 0.0001). Acne is the most common skin condition diagnosed in Hispanics, and this study illustrates a statistically significant reduction in acne in Hispanic patients with moderate-to-severe acne treated with oral sarecycline. Therefore, oral sarecycline shows promising results as a safe and effective treatment for acne in Hispanics.

Antibiotics and Antimicrobial Resistance in Acne: Epidemiological Trends and Clinical Practice Considerations

Antimicrobial resistance is an increasing public health problem worldwide. The interest of a focus on antimicrobial resistance in acne lies on the facts that acne vulgaris (acne) is the most common skin disease worldwide, that the bacterium Cutibacterium acnes (C. acnes, formerly Propionibacterium acnes) plays a key role in the pathogenesis of acne, while at the same time being part of the skin flora, and that antibiotics are commonly recommended for acne treatment. The overuse of topical and/or systemic antibiotics, the long treatment courses used for acne, and the availability of over-the-counter antibiotic preparations, have led to the worldwide emergence of resistant strains in acne patients. In this review, we discuss the epidemiological trends of antimicrobial resistance in acne, the need to avoid the perturbation of the skin microbiome caused by anti-acne antibiotics, and the clinical practice considerations related to the emergence of resistant strains in acne patients. In light of the increasing risk of antimicrobial resistance, raising concerns over the misuse of antibiotics, prescribing patterns can be a critical target for antibiotic stewardship efforts. Also, the selection of non-antibiotic therapies for acne, whenever possible, may offer significant advantages.