Saccharomyces boulardii (CNCM I-745) ameliorates Ovalbumin-induced atopic dermatitis by modulating the NF-κB signaling in skin and colon.

Atopic dermatitis (AD) is a long-lasting allergic disorder characterized by itching, redness, swelling, dry skin, scaling, inflammation, and tissue damage. The exact cause of AD is still unknown. Steroid medications are frequently utilized in treating AD, but their prolonged use can result in complications. Multiple studies suggest probiotics may regulate the immune system, boost immune functionality, or reduce overactive immune responses. The current study investigated the anti-inflammatory, antioxidant, and immunomodulatory role of Saccharomyces boulardii in Ovalbumin (OVA)-induced AD in a murine model. Balb/c mice were sensitized and challenged with OVA to induce AD-like lesions. S. boulardii 1 × 10 CFU/ml/day/mice was orally administrated either as a pretreatment (administered 7 days before OVA induction and continued till day 28) or concurrent treatment (administered from day 1 and continued till day 28). Dexamethasone (5 mg/kg/day) was used as a standard treatment. S. boulardii alleviated the macroscopic and behavioral changes. Blood inflammatory cells were significantly reduced. Serum IgE levels were decreased. Oxidative stress and histopathological changes (epidermal/dermal thickness, inflammatory cells, collagen deposition) in skin tissue were improved. Similarly, the colon's antioxidant capacity and histological architecture were also maintained. Expression of proinflammatory cytokines like TNF-⍺ and IL-1β were significantly reduced in skin and colon tissue. The probiotic S. boulardii under study reduced inflammation by downregulating NF-κB signaling in both skin and colon tissue. This study provides a basis for a possible gut-skin axis, which can be targeted to relieve AD symptoms.