Fucoidan as a marine-origin prebiotic modulates the growth and antibacterial ability of Lactobacillus rhamnosus

Fucoidan has received much attention in healthy food and biomedicine owing to their unique (bio)physicochemical properties, particularly antibacterial and antiviral. Pathogenic microorganisms and probiotics are coexisting in many tissues (e.g., gut, oral, and vagina). However, the effect of fucoidan on probiotics has not been examined. Herein, fucoidan sterilized by different methods (i.e., 0.22 μm filter and high-temperature autoclave) is applied to explore its effect on the responses of Lactobacillus rhamnosus. It is found that high-temperature autoclave treatment causes the depolymerization of fucoidan. Further, the proliferation, morphology, and metabolism of probiotics are greatly dependent on the concentrations of fucoidan. The formation of probiotic biofilm is reduced with an increased concentration of fucoidan. Moreover, the antibacterial ability of probiotics initially increases and then decreases with an increased concentration of fucoidan. Thus, fucoidan could serve as a new marine-origin prebiotic, offering new insight into probiotic modulation and its application in inhibiting bacterial infections.