Effect of Ecklonia cava polyphenol on adiposity reduction is associated with gut microbiota composition in subjects with abdominal obesity: A secondary analysis

Abstract

• Ecklonia cava polyphenol (EP) reduced adiposity in abdominal obese adults. • EP changed gut Firmicutes -to- Bacteroidetes ratio and microbiota composition. • EP-induced microbiota alterations were associated with improved adiposity. • Predicted KEGG pathway revealed metabolic functional alterations by EP. A previous randomized controlled trial showed that Ecklonia cava polyphenol (EP) has the potential to reduce fat accumulation based on clinical outcomes and target gene expression analysis. Here, we investigated whether EP affects gut microbiota composition and impacts clinical outcomes. To this end, we analyzed 16S rRNA sequencing on fecal samples from subgroup subjects with abdominal obesity ( n = 20/group). Compared with the placebo treatment, EP supplementation attenuated the increase of the Firmicutes -to- Bacteroidetes ratio and changed 18 genera composition, including genera related to obesity and fermentation of unabsorbed compounds. Furthermore, Spearman's correlation and Tax4Fun analysis demonstrated that alterations in genera are tightly associated with reducing adiposity via regulating oxidative stress. Together, these findings suggest that the gut microbiota-regulating effect might be a possible mechanism of EP-induced adiposity reduction in subjects with abdominal obesity.