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ARS Home » Plains Area » Grand Forks, North Dakota » Grand Forks Human Nutrition Research Center » Dietary Prevention of Obesity-related Disease Research » Research » Publications at this Location » Publication #413235

Research Project: Modification of Diurnal Patterns to Promote Health in Models for Human Metabolic Dysfunction

Location: Dietary Prevention of Obesity-related Disease Research

Title: Dietary intake of chromista oil alters hepatic metabolomic profile of mice with excess fat mass

Author
item RUST, BRET - Indiana University
item NIELSEN, FORREST - Retired ARS Employee
item Yan, Lin

Submitted to: Nutrition and Metabolic Insights
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/17/2024
Publication Date: 11/19/2024
Citation: Rust, B.M., Nielsen, F.H., Yan, L. 2024. Dietary intake of chromista oil alters hepatic metabolomic profile of mice with excess fat mass. Nutrition and Metabolic Insights. 17. https://doi.org/10.1177/11786388241297143.
DOI: https://doi.org/10.1177/11786388241297143

Interpretive Summary: Both the American Heart Association and the Dietary Guidelines for Americans recommend consumption of two servings of fatty fish per week for the prevention of cardiovascular diseases. Fish oil is a rich source of long-chain n-3 polyunsaturated fatty acids (e.g., docosahexaenoic acid). Available but limited studies have shown that fish oil may be beneficial in reducing the risk of obesity. Considering that over 40% of adults in the U.S. are obese, we investigated the effects of dietary intake of chromista oil (a marine food product) on metabolism in mice with excess fat mass. We found that consumption of the chromista oil diet did not affect body weight and body fat mass in obese mice. However, it increased blood concentrations of adiponectin. Adiponectin is a fat-derived anti-inflammatory hormone which is involved in regulating glucose metabolism and fat breakdown. Its elevation indicates that intake of chromista oil may attenuate obesity-mediated inflammation and metabolic disturbance. Our results show that chromista oil at the dietary content tested in this study does not reduce the body fat mass in this rodent model of obesity. The increase of blood adiponectin in chromista oil-fed mice is an encourage observation and certainly warrants further investigation. This is because the improvement in metabolic health, rather than solely pursuing a reduction in body weight, has gained more interest and become realistic in clinical practice for adults with obesity.

Technical Abstract: Increasing dietary intake of fish oil is frequently recommended for decreasing the risk for cardiovascular disease and improving metabolic health. We hypothesized that dietary intake of chromista oil (a marine food product and a rich source of long-chain n-3 polyunsaturated fatty acids) ameliorates metabolic impairments in mice with excess adiposity. Male C57BL/6NHsd mice were fed a control (n = 12) or a high-fat diet (HFD, n = 24) for 12 weeks to establish excess adiposity. Then, mice fed the HFD were assigned to two groups of 12 each with one continuing being fed the HFD and the other fed the HFD with chromista oil for an additional 12 weeks. Intake of chromista oil did not significantly affect body weight and body adiposity of the mice fed the HFD; mice fed the HFD had significantly more body weight and fat mass than control mice. The flattened daily oscillations of respiratory exchange ratio induced by the HFD was not changed by chromista oil intake. Intake of chromista oil significantly increased plasma insulin concentration, the calculated value of HOMA-IR, and plasma concentration of adiponectin in the mice fed the HFD. Transcription of circadian genes and genes encoding lipid metabolism of the two HFD-fed groups were similar. Untargeted metabolomic analysis showed that intake of chromista oil altered the hepatic metabolomic profile with substantial alterations in amino acid metabolism. Findings from this study indicate that dietary intake of chromista oil does not alter the diminished metabolic flexibility that occurs in mice with excess adiposity induced by the HFD. Targeted metabolomic analysis is warranted to elucidate the effects of dietary chromista oil, as source of n-3 poly unsaturated fatty acids, on metabolism in models of obesity.