Everything that enters our body is made of atoms.  These atoms are arranged into molecules with specific shape and surface chemistry.  It is this molecular structure that can interact with other biochemical molecules that make up our cells, tissues, and organs.  If a molecule that originated outside of our body from food, air, or drug administration bounces into and interacts (sticks) with a biochemical gene product in or near a cell, that molecule has the potential to affect the (up or down) activity of the gene. This change in the gene's purpose could propagate into a macro-effect that we appreciate (not-hungry, fever gone) or one that we want to avoid (allergic reaction, cellular death).

Ayurvedic medicine is a holistic approach to physical and mental health. Ayurvedic medicine is one of the world's oldest medical systems where treatment combines natural products, diet, exercise, and lifestyle to improve health.  For example, when you eat turmeric, a wonderful spice and Ayurvedic medicinal tool, you are ingesting a lot of molecules with different concentrations and structures.  Turmeric powder is primarily carbohydrate but also contains water, protein, fat, dietary minerals, essential oils, dietary fiber, and curcuminoids of which curcumin is of high interest due to its bioactive structure.

Curcumin has many beneficial effects on health including profound anti-inflammatory activity. Curcumin interacts (aka sticks) to about 1000 human proteins encoded in least 981 genes indicating high potential for affecting many biochemical pathways that that are induced by these genes (https://ctdbase.org/detail.go?type=chem&acc=D003474).  Thus, it may be that genetic subsystems including inflammation pathways are modulated through biochemical interactions of human proteins with the curcumin molecule (see below).