Researchers compared intestinal stem cells (ISCs) from young and aged mice and found that ageing was associated with reduced stem cell activity, impaired intestinal regeneration and altered microbial composition within the gut. 

To investigate whether these microbial changes directly influenced regeneration, the researchers transplanted gut microbiota from young mice into aged animals. According to the study, this restored intestinal stem cell activity and improved regenerative responses following intestinal injury. 

The authors also identified specific bacterial populations enriched in aged microbiota that appeared to suppress stem cell function, suggesting that microbial imbalance may contribute directly to age-related regenerative decline.