A new study led by Hartmut Geiger at the University of Ulm, Germany, and Yi Zheng and Kodandaramireddy Nalapareddy at Cincinnati Children's Hospital Medical Center (CCHMC), USA, indicates that age-related alterations in the gut microbiota directly impair intestinal stem cell (ISC) function. The research also suggests that restoring a youthful microbial environment has the potential to reverse this decline. The findings were published in Stem Cell Reports.
The cells lining the intestine undergo continuous renewal to maintain tissue integrity, facilitate nutrient absorption, and support regenerative capacity following injury. Intestinal stem cells (ISCs) drive this process by dividing and maturing to produce the cells of the intestinal lining. With advancing age, ISC activity decreases, which contributes to the development of age-related intestinal conditions, including impaired nutrient absorption, reduced regenerative capacity, and increased inflammation. These factors are key contributors to age-associated intestinal dysfunction.
Researchers observed that ISCs in older mice exhibited significantly lower activity compared to those in younger mice. This resulted in reduced intestinal cell replenishment and impaired regeneration after injury. The study identified that these changes in ISC function coincided with notable differences in the composition of the gut microbiota between young and aged mice.
To investigate whether these microbial changes directly influenced stem cell function, the research team transferred gut microbiota from young donors to older mice. This intervention successfully reversed the age-related decline in ISC activity, leading to enhanced regenerative responses following intestinal injury. The researchers also identified a specific bacterial species, more prevalent in the aged microbiota, that appeared to inhibit ISC function, offering mechanistic insight into how particular microbial shifts contribute to stem cell aging.
The findings demonstrate that the gut microbiota acts as a regulator of intestinal stem cell function and that age-related stem cell decline can be reversible.
This study highlights the microbiota as a critical and modifiable determinant of intestinal homeostasis and tissue regeneration. By establishing a link between microbial composition and stem cell activity, the research emphasizes host-microbe interactions as a potential therapeutic target to preserve intestinal function, enhance regenerative capacity, and promote healthy aging.