Source: Thailand Medical News Jan 28, 2020 4 years, 9 months, 3 weeks, 4 days, 15 minutes ago
For many years, a widespread, fast-growing
algae plant called
Chlamydomonas reinhardtii the green, single-celled organism, which primarily grows in wet soil, has served as a model species for research topics spanning from
algae-based biofuels to plant evolution. While other species of
algae have been used as dietary nutraceuticals that provide beneficial oils, vitamins, proteins, carbohydrates, antioxidants and fiber, the benefits of consuming
C. reinhardtii were previously unexplored.
Now, medical researchers from the University of California San Diego recently completed the first study examining the effects of consuming
C. reinhardtii algae and demonstrated that the algae improves human
gastrointestinal issues associated with
irritable bowel syndrome (
IBS) such as diarrhea, gas and bloating. Results of the project are published in the
Journal of Functional Foods.
Principal investigator and
algae expert Dr Stephen Mayfield, a distinguished Professor in University of California, San Diego's Division of Biological Sciences and co-director of the Food and Fuel for the 21st Century Program (FF21) told
Thailand Medical News, "People have been looking at this
algae for decades, but this is the first study to show what many of us have suspected ie it's good for you. This is exciting because it demonstrates a clear benefit: If you have
IBS-like symptoms, this is good for you."
For almost a decade now, researchers in Mayfield's laboratory have been exploring
C. reinhardtii algae as a cost-competitive and sustainable source of valuable plant-based products, specifically pharmaceuticals and biofuels. Now, working with several collaborators, including UC San Diego's John Chang (School of Medicine), Rob Knight (School of Medicine, Jacobs School of Engineering and Center for Microbiome Innovation) and the San Diego-based startup Triton
Algae Innovations, they turned their attention towards investigating the
algae as a nutritious food additive for improving human health.
Graphical abstract for algae and human gastrointestinal health study. Credit: Mayfield Lab, UC San Diego
The
algae 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 Saf
e" by the U.S. Food and Drug Administration, green-lighting the use of the organism in a human study.
Initial data in mouse studies demonstrated that consuming
C. reinhardtii algae 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.
The Green Algae in powedred form.
Study 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.
Dr Frank Fields, a research scientist in Mayfield's lab and lead author of the paper further added, "The benefits of consuming this species of
algae were immediately obvious when examining the data from both mice and humans who suffered from
gastrointestinal symptoms. I hope that this study helps destigmatize the thought of incorporating
algae and
algae-based products into your diet, it is a fantastic source of
nutrition and we have now shown that this species of
algae has additional benefits to animal and human health."
For the human digestion study, algae were grown in a large stainless steel fermentation
tank, similar to fermentation tanks seen at beer breweries. A smaller bench-top fermentation
tank, or bioreactor, is pictured. Credit: Frank Fields, UC San Diego
Research volunteers also were provided with stool sampling kits and sent samples to the American Gut Project, a citizen science effort led by Knight and his lab, to assess any changes in their
microbiomes. The results indicated that the gut
microbiome composition remained diverse, which is typical of healthier individuals, and that no significant changes to the composition of their gut microbiome occurred during the study as a result of consuming the
algae.
The medical 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.
Reference : Francis J. Fields et al, Effects of the microalgae Chlamydomonas on gastrointestinal health, Journal of Functional Foods (2019). DOI: 10.1016/j.jff.2019.103738
