Microalgae biomass–A source of sustainable dietary bioactive compounds towards improved health and well-being

• The shift to alternative protein sources is mandatory to sustainability. • Microalgae are environmentally friendly and a rich source of bioactive compounds. • Microalgae are associated with several beneficial effects to human health. • Biochemical composition of microalgae biomass depends on cultivation conditions applied. • Microalgae are a rich protein source with the potential to improve human health. Microalgae are recognized as a promising plant-based protein source and are rich in bioactive compounds with potential health benefits. This review explores the role of microalgae bioactive compounds in global health, analysing findings from animal studies and human trials and their possible impact on health. It highlights the bioactive properties of microalgae, which enhance oral, cardiovascular, brain, gastrointestinal, and immune functions, and may help prevent non-communicable diseases like diabetes, hypercholesterolemia, and obesity. The review also examines how cultivation conditions, such as light, temperature, pH, and salinity, influence the content of these compounds. While animal studies offer strong evidence, human trials are still limited but promising. Across the existing human trials, significant benefits were reported, including anti-obesity effects. For instance, the weight loss was enhanced by more than 2-fold with the ingestion of 2 g of Spirulina platensis per day. Optimizing these cultivation parameters is crucial for maximizing the production of bioactive compounds. Further human research is needed to validate the health benefits and ensure the safety of microalgae for long-term consumption. This review encourages future studies on microalgae's health-promoting potential.