Effects of Undaria pinnatifida (wakame) on the human intestinal environment

Abstract

Background: Undaria pinnatifida (wakame) is an edible seaweed. Wakame is a common food in the Japanese diet which exhibits various biological effects. Wakame is rich in dietary fiber. Despite the long history of its intake, changes in the intestinal environment following the ingestion of wakame are unclear.Methods: We examined the effect of a 2-week intake of wakame on defecation frequency and the intestinal microbiota of 22 healthy individuals suffering from low defecation frequency. The clinical trial was designed as an open-label study.Results: Defecation frequency, defined in terms of times per week, days per week, and volume per week significantly increased during the wakame intake period. Furthermore, based on terminal restriction fragment length polymorphism (T-RFLP), the fraction of bifidobacteria as a percentage of all fecal bacteria increased significantly during the wakame intake period. At the phylum, next-generation sequencing (NGS) revealed that the relative abundance of Actinobacteria after wakame intake significantly increased while the abundance of Bacteroidetes decreased. Moreover, species-level analyses revealed that the abundance of Bifidobacterium longum increased significantly after wakame intake. B. longum colony counts on wakame-containing medium were significantly higher than those on medium without wakame.Conclusion: These observations suggest that wakame intake improves intestinal environment and increases the fecal population of bifidobacteria, indicating that it may have prebiotic properties.Keywords: Undaria pinnatifida; wakame; bowel movement; intestinal microbiota; fiber; Bifidobacterium

Addition of Wakame seaweed (Undaria pinnatifida) stalk to animal feed enhances immune response and improves intestinal microflora in pigs

“…We also performed a T-RFLP experiment to determine a broad effect on the microflora and found a significant alteration. In humans, it has been shown that Wakame intake for 2 weeks alters the intestinal flora significantly, in which Lactobacillales increase was observed in T-RFLP analysis (Yoshinaga, Maruya, Koikeda, & Nakano, 2018), which was similar to the results of the present study. In addition, the effect of pure laminarin and alginic acid administration resulted in changes leading to an increase in short-chain fatty acids as metabolites in rat microflora (An, Kuda, Yazaki, Takahashi, & Kimura, 2013).…”

Impact of seaweed intake on health

“…A clinical trial of healthy Japanese women suffering from low defecation frequency (3-5 times/week) (n = 22, aged 40 ± 6.8 years) showed that a 2-week intervention with 4 g of dried wakame per day increased the fraction of bifidobacteria as a percentage of all fecal bacteria, indicating that it may have prebiotic properties 49 .…”

Invasive Seaweeds in the Iberian Peninsula: A Contribution for Food Supply

“…Undaria pinnatifida fatty acids demonstrated antioxidant and antibacterial activity, which can be used in the food industry [ 158 ]. Moreover, several studies have been focused on the application of bioactive compounds extracted from this brown seaweed, such as pigments or polysaccharides as flavor enhancers and to improve the organoleptic properties of food products [ 135 , 159 ].…”

“…Undaria pinnatifida has also proven to possess pharmacological potential, likewise anticancer and anti-inflammatory, which can explain the high interest of this seaweed in the food industry worldwide [ 230 ]. The application of this Asian kelp as a direct food product acts as a prebiotic, enhancing the intestinal microflora, mainly in the quantity of Bifidobacterium longum colony in the human intestine [ 159 ].…”