Project results: How eating a Western diet impacts health

Western Europe underwent a demographic transition a long time ago in which a rural lifestyle was replaced by an urban lifestyle. In some countries in Africa, such as Tanzania and Burkina Faso, a similar transition is now taking place. In these areas, the transition to a rural lifestyle with a Western diet has led to more people living with diabetes or cardiovascular diseases. Inflammatory responses of the immune system are known to play a role play in the development of such diseases. However, important gaps remain in our understanding of how diet and the composition of the gut microbiota influence the function of our immune system.

In the ‘The transition from a traditional toa Western lifestyle and its effect on the interrelation between diet, gut microbiome and health (TransMic)’ project, researchers from the Netherlands, Italy, Germany, Tanzania and Burkina Faso worked together to study the effects of rural and urban food on gut and immune systems. The project ran between 2018 and 2022, and was cofunded by the European Commission within the HDHL-INTIMIC cofunded call.


The TransMic project aimed to study the effects of traditional versus modern, 'Western' diets on the gut microbiome and the functional consequences for health. Data from cohorts from populations in different phases of the demographic transition from Tanzania, Burkina Faso and Europe were used and analysed. In Tanzania, a cohort of 300 healthy persons was enrolled. This cohort consisted of individuals living in either a rural area (with a traditional lifestyle and diet) or an urban area (with a more "Western" lifestyle and diet). In Burkina Faso, a cohort consisting of families (parents and children) living in a rural or urban area were enrolled to study the relationship between diet and gut microbiome composition. Lastly, a short dietary intervention was performed switching healthy young Tanzanian men from a Western to a traditional diet and vice versa, or exposed to a traditional fermented banana beverage, to study the effects on inflammation.


The research found that switching from a traditional (largely plant-based) diet to a high-calorie Western diet can significantly alter the function of the immune- and coagulation system through changes in the gut microbiome composition and active metabolites in the blood. These changes lead to an increased activation of the immune system. The dietary intervention in Tanzania showed that the intake of a fermented banana beverage reduced inflammation and improved blood markers of cardiometabolic health. The project also demonstrated that the transition to a Western diet in Europe has had a negative effect on microbiome diversity. Overall, findings from the TransMic project suggest that dietary interventions can help restore a healthy gut microbiome composition and a more balanced immune system. 

The project researchers received funding within the JPI HDHL NUTRIMMUNE call, to further investigate the relationship between diet and immune function in people with obesity in a project called Transinf (The effect of diet on immune and vaccine responses in people living with obesity in transitioning communities). This study, which started in April 2023, will also take place partly in Tanzania. 

In total, 11 projects were funded within the HDHL-INTIMIC cofunded call. All results will be shared on our website. Stay tuned! See ‘more information’ below for already published project results. 

More information