How a Healthy Gut Microbiome Can Improve Stroke Recovery

                                        Microbiome and Let-7i Effects on Stroke Recovery

In the research paper, Let-7i Inhibition Enhances Progesterone-Induced Functional Recovery in a Mouse Model of Ischemia, the authors Nguyen et al analyze the mechanisms and effects of let-7i, a specific microRNA, on progesterone. They studied the mechanisms of BDNF and Pgrmc1 and how they correlate with let-7i. Pgrmc1 is an important receptor that mediates the effect of progesterone on BDNF release which is essential for recovery. The researchers were able to conclude that let-7i expression increased after ischemic stroke and would decrease the expression and function of BDNF and Pgrmc1. The results showed by inhibiting let-7i, the negative impacts of the pathways were able to be avoided, allowing BDNF and Pgrmc1 to function properly leading to the benefits of progesterone which resulted in improved stroke recovery. 

Similar to this study of the effects of let-7i on stroke recovery, Diana Kwon’s article Targeting Gut Microbiomes May Help Stroke Recovery examines and describes the positive implications a healthy gut microbiome might have on stroke recovery. She describes different work that has been done and the resulting data. She explains how in one study, the researchers were able to find less ischemic brain injury when the mouse’s gut microbiome was changed when given antibiotics. In addition, she also adds that a stroke researcher, Venugopal Venna, has been studying if age-related changes to the microbiome affect recovery. When older mice were given younger microbiota from fecal pellets, they were seen to have better results than those compared to the younger mice that were given older microbiota. The younger mice surprisingly had “higher mortality rates, greater neurological deficits, slower recovery of muscle strength and movement, and increased levels of inflammatory molecules” (Kwon, 2019) when they were induced with ischemic stroke. This experiment is revolutionary and shows an even greater implication of how much of an impact a healthy gut microbiome can have on the brain and how it can lead to better stroke recovery. 

At the end of Kwon’s article, she adds some dissenting opinion and debate from other researchers about whether the data can be applied to humans since all of the experiments have been done on mice. Although there is much work left to be done, one can see that there are still positive implications of stroke recovery in mice from the gut microbiomes. 

Overall, the two articles show that not only can inhibition of let-7i lead to benefits in stroke recovery, but a healthy gut microbiome can also have positive implications for stroke recovery. Hopefully in the near future, scientists will be able to examine both, the effects of healthy gut microbiomes and let-7i inhibition, in humans allowing for improved recovery and treatment in patients with ischemic stroke. 

References

Kwon, Diana. “Targeting Gut Microbes May Help Stroke Recovery.” Scientific American, Scientific American, 19 Nov. 2019, https://www.scientificamerican.com/article/targeting-gut-microbes-may-help-stroke-recovery/ .

Nguyen, Trinh, et al. “Let-7i Inhibition Enhances Progesterone-Induced Functional Recovery in a     Mouse Model of Ischemia.” Proceedings of the National Academy of Sciences, vol. 115, no. 41, 2018, https://doi.org/10.1073/pnas.1803384115.