Research into the causes of multiple sclerosis (MS), especially in the field of genetic risks of this disease, has made immense advances, thanks to new molecular biology techniques and large consortia over recent years. However, the functional relevance of disease-associated risk gene variants remains unclear and representing about one-third of the overall risk as against environmental risk factors plays a subordinate role. Thus, the further identification and, where appropriate, prevention of environmental risks is currently the focus of research. Here recently, above all, risk factors for MS have been shown, which are closely related to western diet and lifestyle, such as high consumption of salt and cigarette smoke. In addition, the human gut continues to be the focus of research: with its large surface, the gut offers immense opportunities for interaction between intestinal bacteria, food and their metabolic products, as well as the immune system associated with the gut. In the present paper, we summarize the findings of the constantly growing research field dealing with the gut, nutrition and MS, and discuss how these findings, as shown recently for fatty acids, could have translational-therapeutic potential.