Nannochloropsis oceanica as a Microalgal Food Intervention in Diet-Induced Metabolic Syndrome in Rats.

Ryan Du Preez,Sunil K Panchal,Lindsay Brown,Marwan E Majzoub,Torsten Thomas

doi:10.3390/nu13113991

Ryan Du Preez, Sunil K Panchal + Show 3 more

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https://doi.org/10.3390/nu13113991

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Journal: Nutrients	Publication Date: Nov 9, 2021
Citations: 17	License type: CC BY 4.0

Affiliation: University of Southern Queensland, UNSW Sydney

Abstract

The microalgal genus Nannochloropsis has broad applicability to produce biofuels, animal feed supplements and other value-added products including proteins, carotenoids and lipids. This study investigated a potential role of N. oceanica in the reversal of metabolic syndrome. Male Wistar rats (n = 48) were divided into four groups in a 16-week protocol. Two groups were fed either corn starch or high-carbohydrate, high-fat diets (C and H, respectively) for the full 16 weeks. The other two groups received C and H diets for eight weeks and then received 5% freeze-dried N. oceanica in these diets for the final eight weeks (CN and HN, respectively) of the protocol. The H diet was high in fructose and sucrose, together with increased saturated and trans fats. H rats developed obesity, hypertension, dyslipidaemia, fatty liver disease and left ventricular fibrosis. N. oceanica increased lean mass in CN and HN rats, possibly due to the increased protein intake, and decreased fat mass in HN rats. Intervention with N. oceanica did not change cardiovascular, liver and metabolic parameters or gut structure. The relative abundance of Oxyphotobacteria in the gut microbiota was increased. N. oceanica may be an effective functional food against metabolic syndrome as a sustainable protein source.

Highlights

Microalgae are unicellular organisms that, in the presence of sunlight, convert carbon dioxide into biomass [1]
Nannochloropsis species contain polyunsaturated fatty acids (PUFA), mainly eicosapentaenoic acid (EPA), polyphenols, carotenoids and vitamins with toxicological tests on animals confirming the safety of this microalga for consumption in food [7]
This study shows that high-carbohydrate, high-fat diet-fed rats supplemented with the microalgae N. oceanica had higher lean mass and lower abdominal and liver fat than rats fed only the obesogenic diet

Summary

Introduction

Microalgae are unicellular organisms that, in the presence of sunlight, convert carbon dioxide into biomass [1]. Nannochloropsis species have a wide range of applications in biotechnology, using techniques to modify biomass composition [4]. As well as minerals, vitamins and antioxidants such as carotenoids [5,6]. Nannochloropsis species contain polyunsaturated fatty acids (PUFA), mainly eicosapentaenoic acid (EPA), polyphenols, carotenoids and vitamins with toxicological tests on animals confirming the safety of this microalga for consumption in food [7]. There are six known species of Nannochloropsis, including N. oceanica, N. gaditana and N. oculata. Baseline information on the biology of N. oceanica has been published for use in the risk analysis of genetically modified N. oceanica in Australia [8]. As one example of its potential, N. oceanica strains isolated in Southeast Queensland, Australia, showed improved lipid characteristics [9]

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