Functionalization of Fiber by the Gut Microbiota as a Marker to Investigate the Effects of Nutrition Transition on Health in Uganda – the UGAFIBER study

• Applicant: Dr. Sören Ocvirk, Ph.D.
• Subject Area: Nutritional Sciences
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 572526698

Nutrition is a fundamental part of daily life and crucial to maintain human health. The global adoption of a Western lifestyle shifted traditional food patterns towards “Western diet” that is low in plant-based foods and associated with high risk of non-communicable diseases (NCD). Originally observed in high-income countries, NCD incidence is rising rapidly in sub-Saharan Africa countries that adopt an urban lifestyle and dietary pattern. Dietary fiber intake is a major distinctive feature along the global Westernization gradient with highest levels of fiber consumption observed in rural communities of the Global South. These diverse plant-derived compounds are indigestible for human digestive enzymes, but can be fermented by specific human gut bacteria to short-chain fatty acids (SCFA) with important health-promoting function. Since low fiber intake leads to a loss of SCFA producing gut bacteria, a “functional bottleneck” exists under Western diet conditions. We have recently started a multidisciplinary clinical trial, the RESISTAR study, where we investigate diet and gut microbiota changes in healthy German volunteers pre- and post-moving to East Africa (Uganda) for 12 months. Here, we aim to add a complementary Ugandan perspective to this ongoing RESISTAR study by implementing a prospective observational study to characterize fiber intake and the gut microbiota in rural and urban Ugandan communities: the UGAFIBER study. We hypothesize that a comparative investigation of Global North to Global South diet patterns with a specific focus on dietary fiber will provide synergistic insights into how diet-associated modulation of the gut microbiota affects NCD risks. Thus, we will recruit healthy Ugandan volunteers from two rural and two urban sites to perform dietary assessment, obtain basic clinical data, collect fecal and food duplicate samples at multiple time points in a prospective setup. This will allow us (1) to assess fiber intake, gut microbiota and NCD risk-associated markers in healthy Ugandan individuals over time. (2) The inclusion of rural and urban communities will allow us to identify differences across a rural-urban gradient in Uganda for the same parameters. (3) Finally, we will be able to perform a cross-sectional comparison of the same samples/data obtained for the RESISTAR volunteers that are based at the same study sites in Uganda – the latter will add a synergistic perspective to the RESISTAR study and allow us to target the fiber-health relationship from both, the German and Ugandan perspective.

• DFG Programme: Research Grants
• International Connection: Uganda
• International Co-Applicant: Dr. Richard Bukenya