Giardiasis is a disease caused by infection with the protozoan "Giardia lamblia". Giardiasis is a disease of the small intestine caused by a protist parasite "Giardia lamblia". Giardiasis is caused by the protozoan "Giardia duodenalis". Protozoa such as "Giardia" may cause longer term disease. Ingestion of contaminated water can produce Giardia infections. Gastrointestinal Parasites Lab studies "Giardia" almost exclusively. This method may not be adequate in killing Giardia cysts in cold water. Many people with "Giardia" infections have no or few symptoms. The vegetable has also been linked to outbreaks of parasitic infestations, including "Giardia lamblia". Lactose intolerance can persist after the eradication of "Giardia" from the digestive tract. Gillin's work reveals why "Giardia" infections are extremely persistent and prone to recur. The life cycle of "Giardia" consists of a cyst form and a trophozoite form. Humans synthesize glutathione, but a few eukaryotes do not, including Fabaceae, "Entamoeba", and "Giardia". New Zealand has "Giardia" but no beavers. Gene probe-based detection is also used to differentiate between species of "Giardia".