Metabolically and immunologically beneficial impact of extra virgin olive and flaxseed oils on composition of gut microbiota in mice.

PURPOSE: Extra virgin olive oil (EVOO) and flaxseed oil (FO) contain a variety of constituents beneficial for chronic inflammation and cardio-metabolic derangement. However, little is known about the impact of EVOO and FO on dysbiosis of gut microbiota, intestinal immunity, and barrier. We, therefore, aimed to assess the impact of EVOO and FO on gut microbiota, mucosal immunity, barrier integrity, and metabolic health in mice. METHODS: C57BL/6 J mice were exposed to a low-fat (LF), lard (HF), high fat-extra virgin olive oil (HF-EVOO), or high fat-flaxseed oil (HF-FO) diet for 10 weeks. Gut microbiota assessment was undertaken using 16S rRNA sequencing. Levels of mRNA for genes involved in intestinal inflammation and barrier maintenance in the intestine and bacterial infiltration in the liver were measured by qPCR. RESULTS: HF-EVOO or HF-FO mice showed greater diversity in gut microbiota as well as a lower abundance of the Firmicutes phylum in comparison with HF mice (P < 0.05). The qPCR analyses revealed that mRNA level of FoxP3, a transcription factor, and IL-10, an inducer of regulatory T cells, was significantly elevated in the intestines of mice-fed HF-EVOO in comparison with mice-fed HF (P < 0.05). The mRNA level of the antimicrobial peptide, RegӀӀӀγ, was markedly elevated in the intestines of HF-EVOO and HF-FO compared with HF group (P < 0.05). CONCLUSIONS: Our data suggest that the consumption of EVOO or FO can beneficially impact gut microbiota, enhance gut immunity, and assist in the preservation of metabolic health in mice.

Activity of xanthine oxidase in plasma correlates with indices of insulin resistance and liver dysfunction in patients with type 2 diabetes mellitus and metabolic syndrome: A pilot exploratory study.

AIMS/INTRODUCTION: There is controversy as to whether hyperuricemia is an independent risk factor for cardiometabolic diseases. The serum level of uric acid is affected by a wide variety of factors involved in its production and excretion. In contrast, evidence has accumulated that locally- and systemically-activated xanthine oxidase (XO), a rate-limiting enzyme for production of uric acid, is linked to metabolic derangement in humans and rodents. We therefore explored the clinical implication of plasma XO activity in patients with type 2 diabetes mellitus and metabolic syndrome (MetS). MATERIALS AND METHODS: We enrolled 60 patients with type 2 diabetes mellitus and MetS. MetS was defined according to the 2005 International Diabetes Federation guidelines. Plasma XO activity was measured by highly-sensitive fluorometric assay measuring the conversion of pterin to isoxanthopterin, and explored associations between the value of plasma XO activity and metabolic parameters. RESULTS: The value of plasma XO activity was correlated with indices of insulin resistance and the level of circulating liver transaminases. In contrast, the level of serum uric acid was not correlated with indices of insulin resistance. The value of plasma XO activity was not correlated with the serum uric acid level. CONCLUSIONS: Plasma XO activity correlates with indices of insulin resistance and liver dysfunction in Japanese patients with type 2 diabetes mellitus and MetS. Through assessing the plasma XO activity, patients showing normal levels of serum uric acid with higher activity of XO can be screened, thereby possibly providing a clue to uncovering metabolic risks in type 2 diabetes mellitus and MetS patients.