Supplementation with Sea Vegetables Palmaria mollis and Undaria pinnatifida Exerts Metabolic Benefits in Diet-Induced Obesity in Mice

Rufa L Mendez; Cristobal Miranda; Courtney R Armour; Thomas J Sharpton; Jan Frederik Stevens; Jung Yeon Kwon

doi:10.1093/cdn/nzaa072

Supplementation with Sea Vegetables Palmaria mollis and Undaria pinnatifida Exerts Metabolic Benefits in Diet-Induced Obesity in Mice

Curr Dev Nutr. 2020 Apr 8;4(5):nzaa072. doi: 10.1093/cdn/nzaa072. eCollection 2020 May.

Authors

Rufa L Mendez¹, Cristobal Miranda^{2

3}, Courtney R Armour⁴, Thomas J Sharpton^{4

5}, Jan Frederik Stevens^{2

3}, Jung Yeon Kwon^{1

6}

Affiliations

¹ Department of Food Science and Technology, College of Agricultural Sciences, Oregon State University, Corvallis, OR, USA.
² Linus Pauling Institute, Oregon State University, Corvallis, OR, USA.
³ Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, USA.
⁴ Department of Microbiology, College of Science, Oregon State University, Corvallis, OR, USA.
⁵ Department of Statistics, College of Science, Oregon State University, Corvallis, OR, USA.
⁶ Seafood Research and Education Center, Oregon State University, Astoria, OR, USA.

Abstract

Background: Sea vegetables are rich sources of nutrients as well as bioactive components that are linked to metabolic health improvement. Algal polysaccharides improve satiety and modulate gut microbiota while proteins, peptides, and phenolic fractions exert anti-inflammatory, antioxidant, and antidiabetic effects.

Objective: We tested the hypothesis that dietary supplementation with either Pacific dulse (Palmaria mollis, red algae) or wakame (Undaria pinnatifida, brown algae) could remediate metabolic complications in high-fat diet-induced obesity.

Methods: Individually caged C57BL/6J mice (n = 8) were fed ad libitum with either a low-fat diet (LFD), 10% kcal fat; high-fat diet (HFD), 60% kcal fat; HFD + 5% (wt:wt) dulse (HFD + D); or HFD + 5% (wt:wt) wakame (HFD + W) for 8 weeks. Food intake and weight gain were monitored weekly. Glucose tolerance, hepatic lipids, fecal lipids, and plasma markers were evaluated, and the gut microbiome composition was assessed.

Results: Despite the tendency of higher food and caloric intake than the HFD (P = 0.04) group, the HFD + D group mice did not exhibit higher body weight, indicating lower food and caloric efficiency (P < 0.001). Sea vegetable supplementation reduced plasma monocyte chemotactic protein (MCP-1) (P < 0.001) and increased fecal lipid excretion (P < 0.001). Gut microbiome analysis showed that the HFD + D group had higher alpha-diversity than the HFD or LFD group, whereas beta-diversity analyses indicated that sea vegetable-supplemented HFD-fed mice (HFD + D and HFD + W groups) developed microbiome compositions more similar to those of the LFD-fed mice than those of the HFD-fed mice.

Conclusion: Sea vegetable supplementation showed protective effects against obesity-associated metabolic complications in C57BL/6J male mice by increasing lipid excretion, reducing systemic inflammatory marker, and mitigating gut microbiome alteration. While the obese phenotype development was not prevented, metabolic issues related to lipid absorption, inflammation, and gut microbial balance were improved, showing therapeutic promise and warranting eventual mechanistic elucidations.

Keywords: Palmaria mollis, Undaria pinnatifida, sea vegetable; gut microbiome; inflammation; obesity.