A recent study demonstrated that administering human umbilical cord-derived mesenchymal stem cells (HUCMSCs) to aged mice led to significant reductions in organ degeneration and notable improvements in behavior and cognitive abilities.

The research focused on four-month-old senescence-accelerated mouse prone 8 (SAMP8) mice, which serve as a model for age-related cognitive decline, and compared them to control mice from the senescence-accelerated mouse resistant 1 (SAMR1) strain.

Fifteen SAMP8 mice received weekly HUCMSC injections for eight weeks, while control groups did not receive any treatment, allowing for a clear comparison of effects.

Post-treatment analysis revealed reduced inflammation in the lungs and spleens of the HUCMSC-treated mice compared to the untreated controls, indicating systemic benefits.

Behavioral assessments showed that treated SAMP8 mice exhibited increased curiosity, improved motor coordination, and reduced anxiety, although no significant differences were observed in spatial learning and memory tests.

Additionally, increased levels of the metabolite 5-hydroxy-L-tryptophan were associated with reduced depression-like behavior in the treated mice, suggesting a normalization of serotonin synthesis.

The study also noted changes in microbial composition and metabolic profiles following MSC treatment, with some beneficial bacterial species restored and an increase in cardiovascular health-related metabolites.

Researchers hypothesized that MSCs might modulate gut microbiota and metabolism through their anti-inflammatory properties and effects on intestinal immune function, creating a positive feedback loop.

While some changes in metabolites aligned with previous research, others indicated limitations in the effects of MSC treatment on metabolism, highlighting the need for further investigation.

Tissue analysis showed significant structural integrity in the frontal lobe and hippocampus of MSC-treated mice, with their cardiac and other organ tissues resembling those of the healthier SAMR1 controls.

Molecular analysis revealed that HUCMSC-treated mice had fewer DNA single-strand breaks in their brain tissue than untreated SAMP8 mice, indicating reduced age-related DNA damage and improved genomic stability.

However, the study faced limitations, including a single time point for microbiome sampling, the specific characteristics of the SAMP8/SAMR1 mouse model, and a relatively small sample size, which may affect the generalizability of the results.