The aim of this study is to evaluate the effect of carboxymethyl-lysine (CML) on the levels of absorption and excretion of CML, and in the microbiota of healthy adults. To achieve the objective, a randomized clinical trial will be carried out. Before the intervention, subjects will have a washout period for seven days, then they will be randomly assigned to either a high-CML or to a low-CML diet for 5 days. Both groups will consume the foods provided by the researchers at the research center. Diets for this intervention will be based on an isocaloric diet that will include breakfast, lunch, snacks and dinner.