Since the Covid 19 pandemic, enhancing the immune system is mainly considered a critical defense system to protect your body from viruses. So in this blog, I would like to discuss one of the means, probiotics, which can be shared to enhance your immunity by fucoidan.  

Fucoidan, a sulfated polysaccharide in brown algae, contains various immunomodulatory effects such as antitumor and antiviral effects. On the other hand, lactic acid bacteria (LAB) also have immunomodulatory effects such as anti-allergic effects.

Among the microorganisms that regulate the intestinal environment, such as lactic acid bacteria, beneficial organisms that can reach the intestines alive are called probiotics. Moreover, oligosaccharides and other nutrient sources that support the growth of probiotics are called prebiotics.

Lactic acid bacteria play a role in suppressing the growth of harmful bacteria such as Escherichia coli (E. Coli) in the intestine and balancing the intestinal bacteria. It improves bowel movements and has various functions such as lowering cholesterol, boosting immune function, and preventing cancer.

According to the study, “A sulfated polysaccharide, fucoidan, enhances the immunomodulatory effects of lactic acid bacteria” by Tadaomi Kawashima et al. demonstrated the enhancement of immunity more with fucoidan and probiotics (LAB).

Researchers had previously reported that KK221 (a halophilic lactic acid bacterium) induces a high level of IL-12 production by macrophages. They are stimulating with KK221 while co-stimulating with fucoidan KK221 enhanced IL-12 production dose-dependent with fucoidan (See Fig. 1A). IL-6 and TNF-α were secreted from peritoneal macrophages in response to fucoidan and KK221 individually, but this IL6 / TNF-α response was enhanced by co-stimulation with fucoidan and KK221 (See Fig. 1B and C). Fucoidan, a carbohydrate component, did not affect cytokine production in response to KK221 (See Fig. 1C). These results indicate that fucoidan and KK221 synergistically enhance the cytokine response of peritoneal macrophages. When analyzed the phagocytosis of KK221 by macrophages, peritoneal macrophages were cultured with FITC-labeled KK221 in fucoidan.

As a result,  the ratio of FITC (used as detection reagents in various applications such as cellular imaging and flow cytometry) + increases with fucoidan supplementation. In addition, macrophages (See Fig. 1D) show that fucoidan is upregulated by KK221 phagocytosis by macrophages.

Oral administration of probiotics LAB was shown to contribute to maintaining immune homeostasis and enhancing systemic immunity via gut-associated lymphoid tissue (GALT), an essential site of host encounter with extrinsic antigens and pathogens.

Since fucoidan improves the KK221-induced APC cytokine response in vitro, fucoidan may also be expected to enhance these various other probiotic effects. Currently, these synergistic effects are induced in LAB and fucoidan in mouse models of autoimmune disease, inflammatory bowel disease, and infection by pathogenic bacteria or viruses.

From the above result, I believe that the synergistic effect of fucoidan and LAB can be expected to have an immunostimulatory effect on viruses in the future.

The graphs below are mouse peritoneal macrophages in BALB / c mice stimulated with KK221 and fucoidan (0-10 µg / ml) for 24 hours.