Apolipoprotein A-IV (ApoA-IV) has been implicated in modulating the gut microbiota. However, chronic high-fat diet (HFD) consumption impairs ApoA-IV signaling and disrupts gut microbial balance, contr Show more
Apolipoprotein A-IV (ApoA-IV) has been implicated in modulating the gut microbiota. However, chronic high-fat diet (HFD) consumption impairs ApoA-IV signaling and disrupts gut microbial balance, contributing to obesity and insulin resistance. This study aimed to investigate the role of ApoA-IV in shaping the gut microbiota and associated metabolic profiles throughout the lifespan of mice exposed to an HFD. Fecal samples were collected from ApoA-IV knockout (KO) and wild-type mice at five time points for microbiota and metabolite profiling using 16S rRNA gene sequencing and gas chromatography-mass spectrometry, respectively. Lifespan was longest in ApoA-IV-KO mice on a normal diet, while the HFD reduced survival across genotypes. Microbiota analysis revealed diet- and age-dependent shifts, including an elevated Firmicutes/Bacteroidota ratio, altered abundance of Show less
While the plasma phylloquinone (PK) concentration is inversely correlated with cardiovascular risk, the involvement of PK in regulating endothelial function has not been directly investigated. Therefo Show more
While the plasma phylloquinone (PK) concentration is inversely correlated with cardiovascular risk, the involvement of PK in regulating endothelial function has not been directly investigated. Therefore, in this study we assessed the effects of short-term treatment with PK-deficient diets (5-10 weeks) on endothelial function in normolipidemic 14-week-old male C57BL/6JCmd mice and age-matched dyslipidaemic male E3L.CETP mice. Our results show that in normolipidemic mice dietary PK deficiency was associated with a marked reduction of PK levels in the plasma and liver (liquid chromatography-mass spectrometry measurements) and with impaired endothelium-dependent vasodilation assessed in vivo by magnetic resonance imaging (MRI). Dietary PK deficiency-induced endothelial dysfunction was fully reversed by PK supplementation. In dyslipidaemic E3L.CETP mice, dietary PK deficiency exacerbated preexisting endothelial dysfunction. Furthermore, dietary PK deficiency decreased menaquinone-4 (MK-4) levels in the aorta but did not affect blood coagulation (calibrated automated thrombography), microbiota composition (culturing and next-generation sequencing), and gut menaquinone production. In conclusion, our study demonstrated for the first time that sufficient dietary PK intake supports endothelial function in normolipidemic and dyslipidaemic mice indicating nutritional significance of dietary PK in the maintenance of endothelial function in humans. Show less