PROFIBER Project
Interactions between protein and fiber sources on gut microbiota and cardiovascular markers
PRO tein source and FIBER interactions on gut microbiome and cardiovascular markers
The impact of protein source, whether plant or animal, on cardiometabolic health and gut microbiota composition is a topic of growing scientific interest. Although plant-based diets are consistently associated with more favorable clinical outcomes, concerns remain regarding the potential adverse effects of high animal protein intake, especially when accompanied by low dietary fiber intake. An emerging hypothesis is that increased fiber intake may attenuate the negative metabolic and microbial effects of protein fermentation in the colon.
The PROFIBER study aims to evaluate the interactive effects of protein source (plant-based versus unprocessed red meat) and dietary fiber intake (low versus high) on cardiovascular risk markers and gut microbiome composition in healthy adults. This is a randomized, controlled, parallel-group clinical trial involving 80 healthy adults. Participants will be allocated to four dietary groups for three weeks: (1) meat diet with typical fiber intake, (2) meat diet with high fiber intake, (3) plant-based diet with typical fiber intake, and (4) plant-based diet with high fiber intake. All diets will be isocaloric and individually adjusted based on energy expenditure, estimated by indirect calorimetry. The primary outcome will be the change in plasma LDL cholesterol concentrations. Secondary outcomes will include inflammatory markers, indices of insulin resistance, endothelial function (assessed by flow-mediated dilation), gastrointestinal symptoms, satiety levels, and gut microbiota composition and functionality.
This study will provide important mechanistic insights into how dietary fiber can modulate the health effects of different protein sources, with a focus on cardiovascular risk and gut microbiota. The results may inform evidence-based dietary guidelines aimed at promoting cardiometabolic health through personalized nutrition strategies.