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

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.

Human milk oligosaccharide 2′-fucosyllactose supplementation improves gut barrier function and signaling in the vagal afferent pathway in mice

“…48 Lachnospiraceae FCS020 is a member of a common butyrate-producing gut bacterial taxa associated with diets high in fiber and complex carbohydrates and a recent study also reported a significant increase in Lachnospiraceae FCS020 group in mice supplemented with polysaccharides, which was associated with improved metabolic profiles including systemic inflammation. 49,50 However, no change in cecal concentrations of butyrate with 2′-FL treatment was detected in the current study.…”

Comparative analysis of macroalgae supplementation on the rumen microbial community: Asparagopsis taxiformis inhibits major ruminal methanogenic, fibrolytic, and volatile fatty acid-producing microbes in vitro

“…Although P. mollis or M. japonica did not reduce methane levels, some seaweeds without anti-methanogenic activity have proven to be potent modulators of rumen microbiomes both in vivo ( Zhou et al, 2018 ) and in a RUSITEC system ( Belanche et al, 2016 ; Zhou et al, 2018 ; Künzel et al, 2022 ) due to the wide range of bioactives present in algae. To our knowledge M. japonica has not previously been evaluated for its effect on microbial communities, while P. mollis has been found to modify the composition of the gut microbial community in mice ( Mendez et al, 2020 ). While unlikely to have any potential as an anti-methanogenic feed additive, future studies may examine higher doses of P. mollis and M. japonica for potential prebiotic effects on the rumen and its microbes.…”

Brown Seaweed Food Supplementation: Effects on Allergy and Inflammation and Its Consequences

“…In recent years, the link between adipose tissue metabolic dysregulation and inflammation has been recognized increasingly [ 35 ]. Several studies investigated metabolic effects of seaweed application, in particular Undaria pinnatifida , in murine models of obesity and type 2 diabetes induced by a high-fat diet [ 36 , 37 , 38 ]. Seaweed was in some studies combined with other nutraceuticals.…”

“…In general, the obesity phenotype did not change, while improvement of glucose regulation was only observed by Oh et al (2016) [ 36 ], but not in the other two studies. Other aspects, however, showed beneficial effects of seaweed supplementation, such as microbiome composition, MCP-1 induction [ 38 ], systolic blood pressure and non-esterified fatty acid levels [ 37 ] or presence of clusters of necrotic adipocytes surrounded by macrophages in adipose tissue (so-called crown-like structures) [ 36 ].…”

“…HFD) fecal cholesterol excretion ↓ ↓ MCP-1 induction obese phenotype not prevented no glycemic improvement in i.p. glucose tolerance test microbiome composition (HFD + seaweed) is closer to LFD than to HFD [ 38 ] whole seaweed, freeze-dried 5% in chow, 16 weeks Undaria pinnatifida ( Up ), Laminaria japonica ( Lj ), Sargassum fulvellum ( Sf ), Hizikia = ( Sargassum ) fusiforme ( Hf ) male C57BL/6N mouse, HFD +/− seaweed supplement 3 body weight or adiposity: no change cf. HFD, except HFD+Up →↑ weight + ↑ subcutaneous adipose tissue adiponectin: ↓ with HFD+Up leptin: ↓ with HFD+Lj, +Sf, +Hf insulin resistance: ↓ w/HFD+Lj blood glucose: ↓ HFD+Lj or +Hf = LFD; HFD+Up = HFD crown-like structures in adipose tissue: ↓ ↓ with all; =LFD LPS-induced pro-inflammatory cytokines by BMDM: ↓ with all [ 36 ] MeOH extract + carob pod 0.1%/0.9%, 4 weeks Undaria pinnatifida male Wistar rat, MetS after 8 weeks western diet 2,3 =body weight, fat mass or muscle =food or energy intake ↓ systolic blood pressure at low dose; ↑ at high dose =CRP ↑ insulin, =glucose ↓ non-esterified fatty acids [ 37 ] hot aqueous extract 500 mg/kg/day started after 2 weeks, for 2 weeks Ecklonia cava female Sprague Dawley rat, letrozole-induced PCOS 2,3 ↓ vaginal leukocyte infiltration restore normal estrous cycle restore normal plasma hormonal levelsnormalize expression of gonadotropin- and steroid hormone-related genes = weight gain upon PCOS induction [ 39 ] 1 Phases of inflammation as indicated...…”