Gut Microbiota and Autoimmune Alopecia Areata: Current Insights from the Literature

Introduction: Alopecia areata (AA) is an immune-mediated disease in which there is non-scarring loss of scalp and/or body hair. Hair loss in alopecia areata results from a breakdown in immune privilege and response to autoantigens. Factors that may lead to the development of the disease include immunological disorders, genetic predisposition, and lifestyle factors. Available treatments mainly focus on reducing disease activity and alleviating symptoms without the possibility of a causal treatment. The gut microbiota, which includes thousands of species of bacteria, develops shortly after birth and is constantly changing under the influence of many factors, such as diet, lifestyle, and the use of certain medications. In order to stay healthy, the microbiota should be in balance with the host, and a breakdown of this balance leads to dysbiosis, which can contribute to the development of many diseases, including autoimmune diseases. Materials and Methods: A systematic literature search was conducted using the PubMed database to identify relevant scientific publications exploring the relationship between alopecia, particularly alopecia areata, and the gut microbiota. The search was performed using the following keywords and their combinations: “alopecia areata”, “gut microbiota”, “microbiome dysbiosis”, “autoimmune disease”, “Lachnospiraceae”, and “Fecal microbiota transplantation”. Conclusion: Recent studies suggest that gut microbiota disturbances may play a role in its pathogenesis. In this review, we analyzed current literature indicating alterations in the gut microbiome of AA patients, potentially contributing to immune dysregulation. Promising results of fecal microbiota transplantation (FMT) in alopecia universalis cases highlight the need for further research into microbiome-targeted therapies for AA.