Kentucky State University Cooperative Extension Connections
Human Nutrition and Food Safety
The physiological pathways through which food influences the body
Key Concept
Food as medicine operates through interconnected body systems such as the gut, immune regulation, and inflammation, rather than through a single targeted mechanism (NCCIH, 2021; NCCIH, 2022).
A healthy diet helps the body stay strong, recover better, and keep its systems balanced. This means food is not important only when a person is sick. It is also important for staying healthy. Food has a strong effect on three main parts of the body: the gut, the immune system, and inflammation. These three components of the body are interconnected. When we eat well, the gut works better, the immune system becomes stronger, and the body can control inflammation more effectively. This helps explain why our daily food choices can have a major impact on our health over time. (NCCIH, 2021; NCCIH, 2022).
Figure 1. The human digestive system and the
function of key organs in the digestive process
In general, minimally processed plant-based diets promote higher levels of microbial diversity and a healthier inner gut. Conversely, diets rich in highly processed foods, low in fiber and high in additives are linked to low microbiome diversity and gut dysfunction (CDC, 2026; NCCIH, 2021).
This is especially true of fiber. Good microbiotas facilitate the fermentation of fiber (prebiotic) obtained from legumes, fruits, and vegetables and release short-chain fatty acids. Dietary fiber from fruits, vegetables, legumes, and whole grains feeds beneficial gut bacteria during digestion,