Circulating Beta-Defensin 2 Levels Correlate with Conventional Inflammatory Markers in Infection-Free Individuals...

Background/Objectives: The role of intestinal dysbiosis as an important driver of inflammation in metabolic disorders is becoming increasingly evident. Beta-defensin 2 is an antimicrobial peptide that contributes to innate immunity, while recently it has been suggested as a novel biomarker of gut dysbiosis. However, its role in obesity remains unexplored. This study aimed to compare circulating beta-defensin 2 levels between individuals with overweight and obesity and lean controls. An additional objective was to explore potential correlations between beta-defensin 2 and other inflammatory markers in this population. Methods: The study population consisted of 81 participants (61.7% females) divided into obesity (n = 27), overweight (n = 34), and normal body mass index (n = 20) groups. All participants were free of infection and diabetes mellitus. Beta-defensin 2, interleukin-6, presepsin, high-sensitivity C-reactive protein (hs-CRP), and ferritin were evaluated in the study groups. Results: We did not find significant differences in beta-defensin 2 levels between the groups (p = 0.936). In contrast, hs-CRP levels were higher in people with obesity compared to the sum of participants in the overweight and control groups (p = 0.044), after adjusting for the effects of age, sex, smoking, and vitamin D status. Furthermore, a positive correlation was established between beta-defensin 2 and presepsin values (p = 0.012). Conclusions: The results of the present study demonstrate that obesity is characterized by an aggravation of inflammation, as expressed by elevated hs-CRP levels. Although the study design cannot prove causal relationships, our findings also suggest that beta-defensin 2 levels correlate with the magnitude of systemic inflammation in infection-free individuals living with obesity. The value of the combined evaluation of different biomarkers in obesity-related outcomes warrants further investigation by larger studies.