The gut flora helps to neutralise some of the toxic by-products of digestion, reduce harmful substances (such as toxins and carcinogens), and discourage 'bad' bacteria and yeasts. It also helps to stimulate the digestive process and aid the absorption of nutrients, as well as producing vitamins including B and K. In addition, the by-products of the growth of beneficial bacteria in the gut help regulate the growth of the gut cells and keep them healthy.