Nutrient Bioavailability From Microalgae

The intervention study is designed to evaluate nutrient bioavailability and physiological impact of two selected microalgae species of interest in a randomized study in humans. The controlled study in parallel design will be conducted with healthy males and females between 20 and 35 years.

The microalgae are selected depending on their contents of long-chain omega-3 fatty acids, e.g. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), high-quality protein (focus: essential amino acids), dietary fibers but also vitamin D pre-cursors and further vitamins, minerals and trace elements.The nutrient bioavailability is evaluated in a controlled, randomized, double-blind study in parallel design. The intervention products (smoothie enriched with Chlorella pyrenoidosa, Nannochloropsis salina) are consumed daily over 14 days. In addition, the background diet is standardised by provision of defined menu plans ensuring an optimal energy and nutrient intake. The control group I receive no intervention products and no menu plans and control group II receive a smoothie without microalage and defined menu plans.

A sup-group of five participants per group consume a test meal after the fasting blood sampling on the first study day. This is followed by a postprandial blood sampling after 30, 60, 90, 120 and 180 minutes.

The NovAL study is conducted to evaluate the bioavailability of nutrients such as omega-3 LC-PUFA, vitamin D, vitamin B12, further vitamins, amino acids, minerals, and trace elements from the selected microalgae species. Therefore, the concentration of these valuable nutrients and relevant markers of their status in humans (e.g. vitamin B12 status: holo-transcobalamin, methylmalonic acid, homocysteine; iron status: ferritin, transferrin, transferrin saturation) are analysed in the human biofluids (serum/plasma, erythrocytes, 24 h urine) before and after defined consumption of the selected microalgae species over 14 days. Besides the comprehensive analysis of the nutrient status in humans, cardiovascular risk factors and risk factors for diabetes mellitus type II are analysed. Thus, the NovAL study allows the assessment of i) the nutrient bioavailability from the selected microalgae species but also ii) their contribution on nutrient supply and prevention of non-communicable diseases such as cardiovascular diseases or diabetes mellitus type.

Eligibility Criteria:
Inclusion Criteria:

* females and males
* BMI \< 30 kg/m2
* subjects must be able and willing to give written informed consent, and to comply with study procedures
* participants following a traditional Western diet composed of dairy products, sausage, meat, fast foods, chocolate and snacks, cereals, vegetables, and fruits (PAL: 1.6)
* precondition: Stable eating habits of at least one years before enrolment
* subjects must have adequate fluency in the German language to complete the questionnaires and understand the nutritional recommendations

Exclusion Criteria:

* subjects with any acute or chronic disease (CVD, tumor, infection, other), gastrointestinal diseases, diabetes mellitus (type I and II), chronic renal disease, diseases of the parathyroid, diseases necessitating regular phlebotomies other chronic diseases which could affect the results of the present study
* use of prescription medicine which could affect results of the study, including systemic glucocorticoids
* intake of lipid-lowering drugs, diabetes medication, hormone replacement therapy
* estimated glomerular filtration (eGFR) rate \< 60 ml/min
* weight loss (≤ 3 kg) or weight gain (≥ 3 kg) during the last three months before study begin
* pregnancy or lactation
* transfusion of blood in the last three months before blood sample taking
* use of dietary supplements incl. multivitamins, fish oil capsules, minerals, and trace elements (three months before and during the entire study period)
* vegetarians, vegans, food allergies
* dependency on alcohol or drugs
* elite athletes (\>10 hours of strenuous physical activity per week)
* simultaneous participation in other clinical studies
* inability (physically or psychologically) to comply with the procedures required by the protocol