We are conducting this study because we want to know if a mindfulness-based cancer recovery (MBCR) program can cause a positive change in the gut microbiome, which is the community of microbes (i.e. bacteria, fungi, and viruses) in your gut. The gut microbiome has been shown to be negatively affected by cancer treatments, and we hope that this MBCR program will reduce the long-term gastrointestinal symptoms caused by these cancer treatments. With 45% of Canadians expected to be diagnosed with cancer in their lifetime, many Canadians have and will be living with these chronic symptoms. As such, our study hopes to find that the MBCR program will improve the overall mental and physical health of people living with cancer by changing the gut microbiota for the better. Understanding this will help us to promote inexpensive and accessible programs to help people with cancer and to develop new ways to reduce chronic health problems after treatment for cancer