Ascophyllum nodosum extract modulates stem cell and immune cell surveillance in an acute placebo-controlled cross-over trial: Implications for healthy aging

Abstrakt

Background: Aging is accompanied by chronic, low-grade inflammation and immune dysfunction, highlighting a need for preventative interventions that boost the body’s immune protection and innate repair mechanisms. Bioactive phytochemicals from functional foods, produced using clean, standardized technologies, are increasingly recognized and in need of scientific validation of effects in humans upon consumption.

Objective: This study evaluated acute effects of a single serving of a brown seaweed extract, PolySea, from sustainable organic wild-harvested seaweed Ascophyllum nodosum on immune activation, anti-inflammatory regulation, and stem cell surveillance in healthy adults. The extract was isolated by green chemistry and had a high content of polyphenols, fucoidan, and the beta-glucan laminarin.

Methods: In a randomized, double-blind, placebo-controlled, cross-over trial, twenty participants in good health consumed 50 mg of PolySea, 300 mg of PolySea, or placebo on three separate visits with at least one week’s wash-out period between visits. Blood draws performed at baseline, 1 hour, and 2 hours post-consumption were analyzed for serum cytokines and changes to immune cell numbers and stem cell numbers. 

Results: Consuming a single serving of PolySea rapidly activated innate immune functions at 1 hour, where pro-inflammatory cytokines (e.g., interferon-γ, interleukin-6) were significantly elevated compared to the levels after consuming placebo. Similar effects on cytokine levels were seen for the 50 mg dose and the 300 mg dose. Concurrently, increased levels of the interleukin-1 receptor antagonist suggested anti-inflammatory restoration. One hour after consuming 50 mg PolySea, there was a mild (4%), transient, and statistically significant increase in the number of monocytes when compared to changes after consuming placebo. A similar increase in the number of non-NK non-T cells was seen at one hour reaching a statistical trend, and at 2 hours, reaching significance. One hour after consuming 50 mg PolySea, the numbers of CD31++CD34- endothelial stem cells were significantly higher in the blood circulation, whereas by 2 hours, CD45dimCD34⁺ pluripotent and progenitor stem cell numbers were significantly reduced, suggesting relocation into tissues. 

Novelty of the study: The study’s novelty lies in quantifying the speed and extent of acute physiological and immunological shifts induced by a single 50 mg serving of the natural seaweed extract within hours, effects that are distinct from and exceed normal circadian dynamics confirmed during the placebo visit.

Conclusion: A single serving of PolySea triggered a coordinated immune and regenerative response by rapidly triggering immune cell surveillance and selective changes to serum cytokine levels, restoring immune balance through anti-inflammatory activity, and selectively affecting different types of stem cells engaged in tissue repair. This biologically integrated response suggests meaningful potential for supporting regenerative physiological functions relevant for healthy aging.

Keywords: Anti-inflammatory; cytokine; fucoidan; immune modulation; laminarin; phlorotannin; polyphenol; senescence.