A gut microbiota-stem cell axis mediates the anti-intestinal aging effect of fucoidan from Apostichopus japonicus.

Fucoidan from Apostichopus japonicus (Aj-FUC) significantly improved intestinal function in d-galactose-induced senescent mice.

• Improvements included restoration of villus structure and colon length
• Enhancement of intestinal motility, absorption, and digestive enzyme activity were observed
• The model used d-galactose (d-Gal)-induced intestinal senescence in mice
• Apostichopus japonicus fucoidan (Aj-FUC) was identified as the major polysaccharide studied

Aj-FUC ameliorated the senescence-associated secretory phenotype and reduced oxidative stress in aging mice.

• Aj-FUC reduced oxidative stress levels in d-Gal-induced senescent mice
• The senescence-associated secretory phenotype (SASP) was ameliorated by Aj-FUC treatment
• Aj-FUC downregulated mRNA expression of senescence markers P16, P21, and P53
• These effects collectively demonstrated 'strong anti-aging effects'

Aj-FUC improved intestinal barrier function by increasing tight junction protein expression.

• Aj-FUC increased both mRNA and protein levels of tight junction proteins
• Increased tight junction protein expression was interpreted as indicating improved intestinal barrier function
• This finding was identified as a distinct mechanism of Aj-FUC's protective effects

Aj-FUC activated the Wnt/β-catenin pathway and promoted intestinal stem cell (ISC) proliferation.

• Aj-FUC activated the Wnt/β-catenin signaling pathway in aging mouse intestines
• Activation of this pathway was associated with promoted proliferation of intestinal stem cells (ISCs)
• ISC-mediated epithelial renewal was identified as a key mechanism of Aj-FUC's anti-aging effects
• The Wnt/β-catenin pathway was identified as downstream of gut microbiota modulation

Aj-FUC remodeled the gut microbiota, specifically enriching Lactobacillus, which promoted ISC growth.

• Aj-FUC remodeled the gut microbiota composition in d-Gal-induced senescent mice
• Lactobacillus was specifically enriched following Aj-FUC treatment
• Enrichment of Lactobacillus was associated with promotion of intestinal stem cell growth
• Gut microbiota modulation was identified as the primary upstream mechanism mediating Aj-FUC's anti-intestinal aging effects
• The authors propose a 'gut microbiota-stem cell axis' as the central mechanistic framework

Aj-FUC was highlighted as a promising marine-based prebiotic functional food ingredient for improving intestinal health during aging.

• Existing anti-aging research on Apostichopus japonicus had primarily focused on bioactive peptides, leaving Aj-FUC largely unexplored
• The intestine was identified as 'a central target in the aging process and the primary site for polysaccharide interaction'
• Aj-FUC's prebiotic potential was linked to its ability to modulate gut microbiota