Does Lactobacillus Reuteri affect Spirometry Parameters in Cystic Fibrosis patients?

<bold>Introduction:</bold> Dysbiosis of the gut microbiome may exacerbate lung disease via the gut-lung axis. Lactobacillus Reuteri (L. Reuteri) is thought to improve digestive health and reduce proteobacterial populations in the gut microbiota, in addition to some advantages in respiratory system including reduced respiratory tract infections. <bold>Aim:</bold> The aim of this study was to investigate whether L. Reuteri impacts spirometry parameters and pulmonary exacerbations in Cystic Fibrosis (CF) patients. <bold>Methods:</bold> We conducted a randomized, clinical trial on 40 Cystic fibrosis patients (mean age of 12 years old) who were assigned to receive a sachet of L. Reuteri or placebo daily for 4 months. The primary endpoints were spirometry parameters including FEV1, FVC, and FEF25-75. <bold>Results:</bold> The median baseline FEV1% in the placebo and intervention groups were 91.05%±11.5, and 87.5%± 21.45 respectively. All Cystic fibrosis subjects showed improvements in FEV1% after study period in which the L. Reuteri group showed an increase of 2% and the placebo group exhibiting a 1.45% increment in FEV1, with no statistically significant difference. (p:.069) No significant differences were observed in FVC and FEF 25-75 differences between the two groups. (p:.162 and p:.211, respectively) Additionally, there was no significant difference in the rate of pulmonary exacerbations between the probiotic and placebo groups. (6 vs. 5, p:. 888) <bold>Conclusion:</bold> This study did not support the efficacy of a L. Reuteri probiotic on improvement of lung function tests in CF patients. It may be concluded that probiotic may not affect pulmonary function test of CF patients higher FEV1 levels.