Abstract
The global coronavirus disease 2019 (COVID-19) pandemic has affected multiple aspects of people's lives, which may also influence the results of studies conducted during this period across diverse research domains. This particularly includes the field of nutritional science, investigating the gut microbiota as a potential mediator in the association between dietary intake and health-related outcomes. This article identifies the challenges currently facing this area of research, points out potential solutions, and highlights the necessity to consider a range of issues when interpreting trials conducted during this period. Some of these issues have arisen specifically because of the measures implemented to interrupt the spread of small acute respiratory syndrome coronavirus 2 (SARS-CoV-2), while others remain relevant beyond the pandemic.