Algae may improve gastrointestinal health, study says

Consuming the green algae C. reinhardtii improves gastrointestinal issues associated with irritable bowel syndrome (IBS) such as diarrhea, gas, and bloating, according to a new study published in the Journal of Functional Foods.

For years, researchers led by Stephen Mayfield, PhD, principal investigator and algae expert from the University of California San Diego, have been exploring C. reinhardtii as a cost-competitive and sustainable source of valuable plant-based products, specifically pharmaceuticals and biofuels. In the current study, they turned their attention towards investigating the algae as a nutritious food additive for improving human health.

The C. reinhardtii biomass used in the study, which was grown by Triton Algae Innovations, was subject to rigorous safety testing and designated as "Generally Recognized As Safe" by the U.S. Food and Drug Administration, green-lighting the use of the organism in a human study.

Preliminary data in mouse studies demonstrated that consuming C. reinhardtii significantly reduced the rate of weight loss in mice with acute colitis, which is generally linked to inflammation of the digestive tract. Building off these results, the researchers set out to test for a similar effect when the algae was consumed by human volunteers, including those with and without symptoms associated with IBS. Volunteers consumed daily spoonfuls of powdered C. reinhardtii biomass and reported their gastrointestinal health for one month. Of the hundreds of interested participants in the project, data from 51 volunteers met the study's requirements for inclusion in the final data analyses.

Results showed that participants who suffered from a history of frequent gastrointestinal symptoms reported significantly less bowel discomfort and diarrhea, significantly less gas or bloating, and more regular bowel movements.

The researchers say much more testing with larger groups of participants across longer time periods is needed. At this point, they are unclear about how the algae works to improve gastrointestinal health. The scientists believe the benefits could be traced to a bioactive molecule in algae or perhaps a change in gene expression of gut bacteria caused by algae consumption.

Still, the observed results in human volunteers led them to conclude in the paper that "the addition of C. reinhardtii into the diet will not only add nutritional value but may also function to relieve some gastrointestinal symptoms of certain individuals."