Algae: The Next Breakthrough in Sustainable Nutrition?
Algae are among the oldest "plants" on Earth, comprising a vast and diverse group of species that vary widely in form and composition depending on their living environments. Humans have utilized algae for a long time, and with deeper scientific exploration, algae have been recognized as materials of significant economic value. They grow rapidly, yield abundantly, and are not only suitable for extracting industrial raw materials but are also edible. More importantly, algae contain a variety of health-promoting bioactive compounds and are regarded as a health food of the 21st century.
Algae are also an appealing source of functional food ingredients because they contain vitamins, proteins, carbohydrates, lipids, minerals, antioxidants, and dietary fibers[1]. Incorporating algal biomass into foods can enhance nutritional quality. Research has already shown that adding algal biomass and algae-derived compounds to food benefits both human and animal health-not only by helping to reduce the risk of certain cancers[2], but also by combating aging, preventing disease, supporting weight management, and reducing inflammation[3].
However, among the thousands of microalgal genera, only a small number can be commercially produced as foods or food ingredients. The U.S. Food and Drug Administration (FDA) has currently granted GRAS (Generally Recognized as Safe) status to the whole-cell biomass of six species for human consumption: Arthrospira (Spirulina), Euglena gracilis, Nannochloropsis oculata, Chlorella vulgaris, Dunaliella spp., and Euglena spp.[5].
FDA-approved whole microalgal biomass for human consumption, along with the compositional reports for each species.
Source: Reference [5]
Among these species, Chlamydomonas reinhardtii is a unicellular eukaryotic green alga that is widely distributed across the globe and grows extremely rapidly. It is also one of the most extensively studied algal species in nature. Currently, it is widely used as a model organism in research on photosynthesis, genetics, and physiology[4]. A recent study conducted by researchers at the University of California, San Diego, suggests that Chlamydomonas reinhardtii may help improve gastrointestinal health[5].
Journal of Functional Foods: Chlamydomonas reinhardtii May Help Improve Gastrointestinal Health
This study, published in the Journal of Functional Foods, investigated the effects of consuming C. reinhardtii and demonstrated its potential to improve gastrointestinal disorders associated with Irritable Bowel Syndrome (IBS), such as diarrhea and bloating[5].
The researchers first conducted an animal experiment using six C57BL/6J mice, which were randomly divided into two groups (n = 3). To induce acute colitis, 4% (w/v) dextran sulfate sodium (DSS) was added to the mice's drinking water for 5 days to disrupt the intestinal mucosal barrier. The mice were then orally administered either 200 μL of phosphate-buffered saline (PBS) as a control or freeze-dried C. reinhardtii (65 g/L) via gavage for 7 days. Body weight was monitored daily for 14 consecutive days to determine whether C. reinhardtii could mitigate DSS-induced weight loss.
The results showed that consumption of C. reinhardtii significantly reduced the rate of weight loss in mice with DSS-induced acute colitis.
Body weight changes in mice following DSS-induced acute colitis
Source: Reference [5]
Based on these findings, the researchers proceeded to investigate whether similar effects could be observed in human volunteers consuming the algae. A total of 133 participants were enrolled and classified into four groups according to the frequency of their gastrointestinal symptoms (GIS). The groups were defined as follows:
(1) LowGIS_1g - low-frequency GIS participants consuming 1 g per day;
(2) LowGIS_3g - low-frequency GIS participants consuming 3 g per day;
(3) HighGIS_1g - high-frequency GIS participants consuming 1 g per day;
(4) HighGIS_3g - high-frequency GIS participants consuming 3 g per day.
Participants were observed for one month to assess gastrointestinal health outcomes. The results showed that individuals with frequent gastrointestinal symptoms experienced significant reductions in discomfort and diarrhea after consuming the algal product, along with improved bowel regularity.
Taxonomic composition of microbial phyla in fecal samples
Source: Reference [5]
Studies have shown that Rheinichlorella provides additional benefits for both animal and human health, adding further evidence to the algal ingredients market. According to Innova Market Insights, the algal ingredients market is continuously growing, and the prospects for algal supplements are broad. It is expected that an increasing number of modern clinical studies will confirm the positive effects of certain algae on human health in the future.
Reference:
[1] A.P. Batista, L. Gouveia, N.M. Bandarra, J.M., Franco, A."Raymundo. Comparison of microalgal biomass profiles as novel functional ingredient for food products".Algal Research, 2(2013).
