ANDROGENETİK ALOPESİ HASTALARINDA BAĞIRSAK MİKROBİYOMUNUN DEĞERLENDİRİLMESİ VE SERUM IL-22 DÜZEYİ İLE İLİŞKİSİ

Abstract

Şahin B.A. Evaluation of Gut Microbiome in Patients with Androgenetic Alopecia and Its Relationship with Serum IL-22 Levels, Hacettepe University Faculty of Medicine, Thesis in Dermatology and Venereology, Ankara 2024. Androgenetic alopecia (AGA), the most common type of progressive, non-scarring hair loss, is a polygenic and hormonal condition characterized by variability in the severity of hair loss, age of onset, and areas of scalp involvement. Early-onset AGA has been increasingly associated with conditions such as coronary artery disease (CAD), hypertension, type 2 diabetes mellitus (T2DM), polycystic ovary syndrome (PCOS), and metabolic syndrome. Dysbiosis in the gut is believed to play a significant role in the pathogenesis of these conditions. Additionally, a relationship between IL-22 levels and the gut microbiome has been identified in the literature. This study aimed to evaluate the gut microbiome and serum IL-22 levels in individuals diagnosed with AGA, comparing them with healthy individuals to elucidate their roles in the pathogenesis of AGA. To our knowledge, no previous studies on this topic have been conducted in our country. The study included 15 male AGA patients and 15 healthy male controls aged 18-35 years. Demographic and clinical data of participants were recorded. Stool samples were analyzed using metagenomic methods, and IL-22 levels were measured. The mean age of the patient group was 25.87 ± 4.76 years (range: 18-35), and the mean age of the control group was 25.80 ± 4.65 years (range: 20-35). Statistically significant differences were observed between the patient and control groups in terms of meal patterns (p=0.039), nighttime eating habits (p=0.025), breastfeeding duration (p=0.005), and history of intensive antibiotic use during the first 6-7 years of life (p=0.022). At the phylum level, the gut microbiome beta diversity was significantly different between the patient and control groups (Bray-Curtis dissimilarity index, p=0.002). The Bacillota (p=0.002) and Thermodesulfobacteriota (p=0.02) phyla were decreased in the patient group, while the Bacteroidetes (p=0.0006) phylum was increased. Furthermore, the alpha diversity of the gut microbiome at the genus and species levels was significantly lower in the patient group compared to the control group (Genus-level InvSimpson diversity index, p=0.006; species-level InvSimpson diversity index, p=0.01). In conclusion, 3 phyla, 27 genera, and 53 species showed statistically significant differences in the gut microbiome of AGA patients compared to healthy controls. These findings support the hypothesis that the gut microbiome may play a role in the pathogenesis of AGA. However, no significant difference was found between the patient and control groups in terms of IL-22 levels (p=0.119). These findings need to be validated through larger-scale studies with more patients.