In the simplest of terms, a lectin is a type of protein that acts as a selective Velcro-like material. They come in two main forms, single and double-sided. The single sided lectins only stick to other things. Cells in the liver have this type of lectin on their surfaces to snatch up harmful bacteria and parasites that may be present. Two sided lectins stick two other cells together, like a piece of double-sided tape between objects. Both varieties, despite their differences, have many commonalities.
Although both the single and double sided kinds both cause agglutination (the clumping of particles), they do so in specific, individualised ways. Each lectin has a certain type of material it is meant to bind to and this changes depending on what species the reaction is occurring inside as well as the blood type of the person or animal involved. The source of the lectin itself also has a great bearing on how it will react. For example, the lectin found in wheat is different from the one found in soy, both in its appearance and how it interacts with different sugars. Understanding the source of the lectin and the chemistry of the person consuming it is at the center of eating right for your blood type.
