Immune system health and the role of nutrition and gut integrity

Recent scientific research highlights the complex relationship between diet, gut health, and immune system function. A 2025 systematic review in the International Journal of Molecular Sciences suggests that functional foods containing bioactive compounds—such as vitamins, minerals, and probiotics—can support immune responses through antioxidant and anti-inflammatory pathways.

Specific foods like garlic have been noted for their ability to stimulate immune cells, including macrophages and lymphocytes, due to compounds like allicin. Similarly, citrus fruits are recognized for their high vitamin C content, which supports the production and function of immune cells.

In addition to nutrition, the physical integrity of the gastrointestinal tract plays a critical role. A study published in The Journal of Immunology suggests that increased intestinal permeability, often called "leaky gut," may influence the severity of food allergies. Using mouse models, researchers observed that higher gut permeability was linked to more severe allergic reactions and shifts in immune cells, such as increased Th2 cells and fewer Treg cells. The study indicates that the gut microbiome and intestinal barrier are closely connected to immune system responses.