Polyphenols found in fruits and vegetables are associated with a reduced incidence of cardiovascular disease (CVD), the leading cause of death in the USA. Our lab demonstrated that blackberry supplementation reduces atherosclerosis in male, but not in female mice. The current study investigates whether gallic acid (GA), a polyphenol abundant in blackberry, decreases plaque and whether its effect is also sex-dependent. In vitro work using vascular smooth muscle cells (VSMCs) demonstrated that GA reduced cell signaling associated with proliferation, migration, and senescence. ApoE−/- male and female mice were treated with and without 0.2% GA in drinking water and fed a chow diet (2 weeks), then switched to high-fat diet (HFD) (5 weeks) with the same GA regimen. Similar to the blackberry study, GA reduced atherosclerosis only in males. This GA-induced plaque reduction was independent of plasma cholesterol, triglycerides (TG), LDL, or HDL but corresponded with indices of lower inflammation. Males showed reduced spleen weight and serum IL3 and IL12 levels, and gut health improvement. In females, GA increased anti-atherogenic (HDL and IL10) molecules, while upregulating several pro-inflammatory cytokines and chemokines, including tumor necrosis factor α (TNFα). A major sex-dependent effect of GA was the almost complete disappearance of Eubacterium fissicatena and Turicibacter induced by HFD in males, a finding not seen in females. This study provides novel insights into how GA can improve gut microbiota alterations associated with CVD and suggests that males suffering from atherosclerosis may benefit from GA supplementation, as this polyphenol partially restored microbiome dysbiosis.

Gallic acid

Turicibacter

Atherosclerosis

VSMC

Eubacterium fissicatena

3-O-caffeoylquinic acid

analysis of variance

amplicon sequence variants

C-C motif chemokine ligand

cardiovascular disease

colony stimulating factor

C-X-C motif chemokine ligand

Dulbecco's phosphate buffered saline

Fluorescein di‐β‐d‐galactopyranoside

glutathione peroxidase

high-density lipoprotein

linear discriminatory analysis

linear discriminatory analysis effect size

low-density lipoprotein

nicotinamide adenine dinucleotide phosphate

nuclear factor kappa B

operational taxonomic unit

principal coordinate analysis

permutational analysis of variance

reactive nitrogen species

reactive oxygen species

senescence associated beta galactosidase

senescence associated secretory phenotype

standard deviation of mean

stress induced premature senescence

trimethylamine-N-oxide

vascular cell adhesion molecule

very low-density lipoprotein

vascular smooth muscle cell

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