Probiotics, or foods which contain live bacteria, have been shown to have a definite and tangible effect on your metabolism. There is already evidence which suggests that adding ‘friendly’ bacteria to your gut can help your digestive system. But the first detailed research into how probiotics change the biochemistry of gut microbes has found that treatment with probiotics has a whole range of biochemical effects. Probiotics can change the makeup of the bugs in your gut, not only by increasing the number of ‘friendly’ bacteria, but also because different types of bacteria work together, amplifying the effects. One biochemical change observed was a change in the metabolization of bile acids, which can affect how much fat your body is able to absorb. Abnormalities in some types of gut microbes have been linked to diabetes and obesity.