As many of my patients know, I am keen on good gut health (read Gut by Giulia Enders) and I often suggest taking a daily probiotic to improve gut health and increase immunity (75 to 80% of our immunity lies in our gut). But, if you are investing in those expensive probiotics, do bear in mind you need to filter your water. Chlorine added to our drinking water can destroy helpful “good” gut bacteria much like antibiotics do. See Gut Health Project for more details. So, do filter your water, very important.