Abstract Body: Background: Taurine is a sulfur-containing amino acid present in most mammalian tissues that plays a critical role in regulation of numerous physiological processes. Taurine has been recently identified as a potential neuroprotective agent due to its potent antioxidant and anti-inflammatory properties. However, its effects on stroke recovery are unexplored. Here, we investigated the effects of chronic taurine supplementation on immune cells and recovery in aged stroke mice.

Hypothesis: We hypothesized that aged stroke mice treated with taurine will show enhanced recovery compared to vehicle-treated mice. We examined if this beneficial effect was independent of infarct size and was associated with changes in immune cell responses.

Methods: Human plasma samples were assessed by mass spectrometry in control and stroke patients. For murine studies, aged (16-18 months) C57BL/6 WT mice were subjected to a reversible 60-MCAO. Three days after stroke, mice were randomly assigned into two groups: one received taurine (n=6M,10F) and the other received water without taurine (n=5M,11F). Behavioral tests were performed at intervals until euthanasia on post-stroke day 42. Flow Cytometry (FACS) was performed to assess for cellular changes in the blood and tissues. Finally, as gut microbiota composition is implied in immune regulation, we determined changes in the microbiota following taurine treatment by performing 16s analysis on fecal samples.

Results: First, we compared plasma taurine levels in healthy controls (n=20) and acute stroke patients (n=29) obtained through unbiased metabolomics. Taurine was significantly lower in stroke patients (p<0.05 by t test). We found plasma taurine levels decline after stroke in aged mice (p<0.05; n=6/grp). Post-stroke taurine supplementation in females resulted in significant regain of body weights (p<0.05). Mice received taurine had altered microbial composition and had a significant improvement in grip strength as early as 24 days after stroke (p<0.05), and improved neurological scores by day 18 in both males (p<0.05) and females (p<0.05) compared to controls. FACS data showed an increased number of B cells in the blood of taurine treated mice compared to controls (p<0.01).

Conclusion: Our results show that stroke reduces taurine levels. Taurine significantly enhanced stroke recovery and led to immune cell changes in aged mice. These findings highlight a potential role of taurine as a therapeutic to enhance post-stroke recovery.