A single-center randomized prospective study published in The Laryngoscope evaluated whether add-on OM-85 could reduce postoperative nasal polyp recurrence. One hundred patients were randomized to OM-85 or control groups, with 34 and 43 patients, respectively, completing the 12-month follow-up. OM-85 was administered orally for 10 days followed by a 20-day washout during Months 1โ€“3 and 7โ€“9. Polyp recurrence was significantly lower with OM-85 than control therapy (8.82% vs 27.91%; ฯ‡ยฒ=4.408, P=.036).

Preoperative Lund-Mackay score (P=.008) and hyposmia visual analogue scale score (P=.031) were significant predictors in univariable analysis. Lund-Mackay score remained an independent predictor in multivariable analysis (odds ratio, 1.15; P=.012), with an optimal cutoff of 10. At 6 and 12 months, OM-85 significantly improved nasal obstruction, olfactory dysfunction, mucopurulent discharge,โ€ฆ