When it comes to gut health, we may be only as “old” as the bacteria living in our intestines.
In research published Jan. 22, 2026, in Stem Cell Reports , a research team from Cincinnati Children’s and Ulm University in Germany demonstrates that transferring young microbiota to the intestines of older mice helps boost the stem cells that make new tissue. This in turn can speed healing when intestines are damaged by causes ranging from surgery and radiation treatments to disease, infections and the natural wear and tear of aging.
“As we age, the constant replacement of intestinal tissue slows down, making us more susceptible to gut-related conditions. Our findings show that younger microbiota can prompt older intestine to heal faster and function more like younger intestine,” says corresponding author Hartmut Geiger, PhD, director of the Institute of Molecular Medicine at Ulm University and former member of the Division of Experimental Hematology and Cancer Biology at Cincinnati Children’s.
While a variety of prebiotic and probiotic products have surged in popularity, this study involved controlled experiments involving a mix of bacteria not available in consumer products. The researchers emphasize that these microbiota require delivery via fecal transfer.
The power of young bacteria
In a series of experiments involving mouse models, the team demonstrated that aging results in changes to the mix of commensal (or helpful) microbiota in the gut. This specifically reduced key signaling involving the gene Ascl2 and WNT signaling among the intestinal stem cells (ISCs) within the intestine lining.
“This reduced signaling causes a decline in the regenerative potential of aged ISCs,” says co-author Yi Zheng, PhD , director, Division of Experimental Hematology and Cancer Biology at Cincinnati Children’s. “However, when older microbiota were replaced with younger microbiota, the stem cells resumed producing new intestine tissue as if the cells were younger. This further demonstrates how human health can be affected by the other life forms living inside us.”
Zheng and Geiger have collaborated on previous projects focused on rejuvenating blood stem cells. They also are co-founders of a related start-up company called Mogling Bio . This study involving intestinal stem cells extends some of their previous work, Zheng says.
The research team stressed that more study is needed to confirm the benefits also occur in humans, including determining safe dosing levels and further investigation of the ideal combination of microbiota species to include in fecal transfers.
About the study
Several other Cincinnati Children’s experts collaborated on this study, including first author Kodandaramireddy Nalapareddy, PhD, David Haslam, MD, and Theresa Alenghat, VMD, PhD. The Research Flow Cytometry Facility and the Comprehensive Mouse and Cancer Core at Cincinnati Children’s also contributed to this project.
Funding sources included grants from the U.S. National Institutes of Health ( R01DK104814 , R01AG063967 , P30DK078392 , and R01AG040118 ) and the Baden-Württemberg Foundation in Germany.
Stem Cell Reports
Experimental study
Animals
Microbiota from young mice restore the function of aged ISCs
22-Jan-2026
The authors declare no conflicts of interest