Fucoidan attenuates age-related skeletal muscle atrophy via gut microbiota-dependent tryptophan metabolic Remodeling.

Fucoidan supplementation improved muscle mass, fiber size, and glycogen storage in aged mice.

• Eighteen-month-old aged mice were orally administered Fucoidan at 400 mg/kg/day for 12 weeks.
• After 12-week supplementation, muscle mass, fiber size, and glycogen storage were improved.
• Atrophy markers Fbx32 and MuRF1 were downregulated following Fucoidan treatment.
• The myogenic factor MyoD1 was upregulated following Fucoidan treatment.

The muscle-protective effects of Fucoidan were dependent on gut microbiota.

• Cohousing experiments were used to validate gut microbiota dependency of Fucoidan's effects.
• Antibiotic-induced microbiota depletion models were employed to confirm gut microbiota dependency.
• Cohousing transfer experiments showed that the beneficial effects could be transmitted via gut microbiota.
• In vitro human fecal fermentation was integrated to further validate gut microbiota dependency.

Fucoidan reshaped gut microbial communities and enhanced tryptophan metabolic flux in aged mice.

• Multi-omics analyses revealed that Fucoidan reshaped gut microbial communities.
• Fucoidan supplementation enhanced tryptophan metabolic flux.
• Tryptophan metabolic remodeling was confirmed in microbiota-depleted models.
• Tryptophan metabolic remodeling was confirmed in in vitro fermentation experiments.

Fucoidan, a sulfated polysaccharide from marine algae, exhibits prebiotic and anti-aging properties relevant to the gut-muscle axis.

• Fucoidan is a sulfated polysaccharide derived from marine algae.
• The gut-muscle axis has emerged as a critical regulator of muscle homeostasis.
• Dietary interventions targeting gut microbiota show promise for age-related skeletal muscle atrophy.
• Prior to this study, Fucoidan's effects on age-related skeletal muscle atrophy had not been explored.