Immunity Fuel NZ Certified Organic Probiotic Superfoods. Immunity Fuel Probiotic Superfood is one of the most potent natural probiotic superfoods in NZ. It is fermented for 3 weeks during which time the bacteria pre-digest the wholefoods so the nutrients can be instantly absorbed by your body's cells. Immunity Fuel is a unique health supplement with a combination of probiotics, prebiotics and natural multi vitamins from wholefoods. It is New Zealand's premium, results oriented all in one natural probiotic and multi vitamin. The best probiotics in NZ - to live our best lives.