Immune Modulation Through Long‐Term <i>Lacticaseibacillus rhamnosus</i> Therapy in Home Mechanically Ventilated Patients

The beneficial effects of probiotics on the immune system are well established; however, the precise mechanisms underlying their action remain incompletely understood. To date, the impact of probiotics in home mechanically ventilated (HMV) patients has not been investigated. This study evaluated the effects of oral supplementation with Lacticaseibacillus rhamnosus GG ATCC 53103 (LGG) on nasal microbiota composition and selected immune parameters in HMV patients. Thirty-one individuals, following a 3-month probiotic-free washout period, received LGG at a dose of 8 × 10⁹ CFU/day for 6 months. Nasal swabs and blood samples were collected at baseline, and after 3 and 6 months, to assess nasal microflora, Th1/Th2 balance, and levels of IL-2, IL-4, IL-5, IL-10, TNF-α, and IFN-γ. A statistically significant increase in IL-2 was observed at both 3 and 6 months (p = 0.0307; p = 0.0001, respectively), along with a transient rise in IFN-γ at 3 months (p = 0.0253) and IL-4 at 6 months (p = 0.0297). The IFN-γ/IL-10 ratio also increased at 3 months (p = 0.0394). No significant changes were detected in the remaining cytokines or nasal bacterial flora. Notably, none of the participants required antibiotic therapy during the intervention period-contrasting with prior seasons, when at least one course was typically necessary. Given the critical role of IL-2 and IFN-γ in anti-infective immunity, their elevation may indicate enhanced resistance to infection, while increased IL-4 may reflect modulation of inflammation. These findings suggest that LGG supplementation, due to its safety, affordability, and immunomodulatory potential, may be a valuable adjunctive strategy to reduce infection risk and improve outcomes in HMV patients.