Background/Aims: Intakes of certain flavonoids influence gut microbiota and immune functions. Aberrations in CF gut microbiota have been reported and may link to CF airway microbiota and respiratory complications. Relationships between flavonoid intakes and gut microbiota in adults with CF were therefore investigated.
Methods: Flavonoid intakes of 16 free-living adults with CF were estimated using a validated flavonoid-specific food frequency questionnaire. Extracted faecal sample DNA was sequenced using 454 pyrosequencing targeting the bacterial 16-small subunit ribosomal DNA V1-V3 regions. Sequences were assembled and taxonomy assigned using the Quantitative Insights Into Microbial Ecology pipeline, and unweighted and weighted UniFrac distances between samples calculated. Associations between the gut microbiota variations based on these distances and standardised dietary flavonoid intakes were analysed using adonis test. Flavonoids significant at a false discovery rate (FDR)=0.3 were subjected to Spearman correlation tests with standardised relative abundances of bacterial taxa (FDR=0.3).
Results: Gallocatechin intakes (p=0.047,q=0.285) correlated with overall gut microbiota variations using unweighted UniFrac distances, and apigenin (p=0.028,q=0.227) and kaempferol (p=0.029,q=0.227) intakes and %flavones (p=0.013,q=0.227) and % flavonols (p=0.016,q=0.227)(both excluding tea) correlated with weighted UniFrac distances. Gallocatechin intakes correlated positively with genus Actinomyces and family Actinomycetaceae (Actinobacteria), and negatively with class Coriobacteriia (Actinobacteria).
Conclusion: Intakes of certain flavonoids may be associated with gut microbiota variations, presenting implications for metabolism, immune function and inflammation which affect CF co-morbidity management.
Funding sources: LL received an APA PhD scholarship and an Australian Cystic Fibrosis Research Trust PhD Student Fellowship. Funding sources were independent of study conception or manuscript preparation.