A NATURAL compound derived from Bacillus subtilis bacteria significantly slows vitiligo progression and may restore pigmentation, according to a new preclinical study in mice.
Vitiligo is a complex autoimmune condition in which the body’s immune system mistakenly targets and destroys melanocytes, the cells responsible for skin pigmentation. The resulting loss of pigmentation leads to visible skin patches, which can cause significant psychological distress. Current treatments, including the FDA-approved Opzelura (ruxolitinib) cream, have limitations, with only 30% of patients experiencing significant repigmentation. Seeking alternative approaches, researchers investigated exopolysaccharides (EPSs) derived from Bacillus subtilis, a gut-friendly bacterial strain, as a potential therapy for vitiligo.
In this study, researchers administered weekly intraperitoneal injections of EPS to vitiligo-prone h3TA2 mice over 18 weeks, assessing depigmentation levels and immune responses. Results showed a 74% reduction in pigment loss on the mice’s backs compared to untreated controls. EPS treatment altered immune cell populations, reducing CD8+ cytotoxic T cells—known for attacking melanocytes—while increasing protective regulatory T cells in the skin. Furthermore, treated mice exhibited higher levels of M2 macrophages and indoleamine 2,3-dioxygenase expression in the spleen, shifting cytokine responses toward an anti-inflammatory type 2 profile. Splenocytes from treated mice also demonstrated reduced inflammatory cytokine release when exposed to tyrosinase peptides, suggesting a systemic modulation of immune activity.
These findings highlight the potential of EPS as a novel treatment strategy for vitiligo, offering an alternative or complementary approach to existing therapies. If translated into human treatment, EPS could be delivered as an injectable therapy, oral supplement, or topical ointment. Further research is required to determine optimal administration, duration of efficacy, and synergy with current treatments. Given vitiligo’s disproportionate impact on individuals with darker skin tones and its association with other autoimmune disorders, this microbial-based approach could offer significant clinical benefits. Future studies will focus on refining the compound and evaluating its potential for broader autoimmune disease applications.
Katrina Thornber, EMJ
Reference
Touni A A. et al. Bacillus subtilis–derived exopolysaccharide halts depigmentation and autoimmunity in vitiligo. Journal of Investigative Dermatology. 2024;DOI:10.1016/j.jid.2024.12.006.
