Impact of a Healthy Dietary Pattern on Gut Microbiota and Systemic Inflammation in Humans

Abstract

Gut microbiota have recently been suggested to play a part in low-grade systemic inflammation, which is considered a key risk factor for cardiometabolic disorders. Diet is known to affect gut microbiota; however, the effects of diet and dietary components on gut microbiota and inflammation are not fully understood. In the present review, we summarize recent research on human dietary intervention studies, investigating the effects of healthy diets or dietary components on gut microbiota and systemic inflammation. We included 18 studies that reported how different dietary components altered gut microbiota composition, short-chain fatty acid levels, and/or inflammatory markers. However, the heterogeneity among the intervention studies makes it difficult to conclude whether diets or dietary components affect gut microbiota homeostasis and inflammation. More appropriately designed studies are needed to better understand the effects of diet on the gut microbiota, systemic inflammation, and risk of cardiometabolic disorders.

Keywords: diet; gut microbiota; humans; inflammation; intervention studies.

Figure 1

Impact of dietary fat (SFA versus PUFA) and fiber on gut microbiota and metabolic regulation. SFA is well known to induce metabolic dysregulation, while PUFA and fiber are well known to improve metabolic regulation. High intake of SFA will increase the cholesterol level in blood, which is an important risk factor for CVD. PUFA and fiber will decrease blood cholesterol and triglycerides, in addition to improve blood glucose regulation. The underlying mechanism of cardiometabolic disorders is inflammation. Both fiber and fat may change the gut microbiota composition. However, whether gut microbiota regulate inflammation directly by dietary interventions in humans is still to be elucidated. CVD: Cardiovascular diseases; PUFA: polyunsaturated fatty acids; SFA: saturated fatty acids.