Correlation of Gut Microbiota, Vitamin D Status, and Pulmonary Function Tests in Children With Cystic Fibrosis

Hadeel Albedewi; Iman Bindayel; Ahmed Albarrag; Hanaa Banjar

doi:10.3389/fnut.2022.884104

Correlation of Gut Microbiota, Vitamin D Status, and Pulmonary Function Tests in Children With Cystic Fibrosis

Front Nutr. 2022 Jun 9:9:884104. doi: 10.3389/fnut.2022.884104. eCollection 2022.

Authors

Hadeel Albedewi¹, Iman Bindayel¹, Ahmed Albarrag², Hanaa Banjar³

Affiliations

¹ Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
² Department of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
³ Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.

Abstract

Background: Children with cystic fibrosis (CF) are expected to have suboptimal serum vitamin D status and altered gut microbiota. The altered gut microbiota is hypothesized to have a pro-inflammatory effect that further complicates the existing respiratory inflammation. Emerging evidence suggests an association between vitamin D and gut microbiota. The aim of this study was to assess the relationships between 25-hydroxyvitamin D [25(OH)D] status, pulmonary function, and fecal bacteria in children with CF.

Methods: In this cross-sectional study, a total of 35 children with CF (8.7 ± 2.83 years) and 24 controls without CF (9 ± 2.7 years) were included in this study. Serum 25(OH)D status was measured using the Elecsys vitamin D total II assay. In the CF group, gut microbiota composition was assessed using real-time PCR analysis. Pulmonary function tests (PFTs) were measured using spirometry. Comparisons between the CF and non-CF controls were conducted using the independent sample t-test. In the CF group, one-way analysis of variance (ANOVA) was used to assess differences in PFTs and gut microbiota composition across the three vitamin D subgroups. The correlations between 25(OH)D status and PFTs, or gut microbiota composition, and PFTs with gut microbiota composition were analyzed using the Pearson's correlation coefficient test.

Results: Children with CF had significantly lower serum 25(OH)D levels compared with children without CF (44.3 ± 22.4 vs. 59 ± 25.5, respectively, P = 0.026). Children with CF with optimal serum 25(OH)D level had significantly higher levels of Bacteroidetes, Firmicutes, and total bacteria (P = 0.007, P = 0.007, and P = 0.022, respectively). The level of Firmicutes was found to be significantly higher in mild forced expiratory volume in 1 s (FEV1) compared with moderate FEV1 (P = 0.032), whereas the level of the other bacteria species was comparable across FEV1 severity groups.

Conclusion: Our findings may encourage studies that target and modify gut microbiota to potentially achieve better outcomes in terms of respiratory function in CF.

Keywords: 25-hydroxyvitamin D; cystic fibrosis; gut microbiota; pulmonary function tests; real-time PCR.