No scientific evidence indicates that parasites are the key cause of autoimmunity

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A TikTok video posted on 23 June 2023 claimed that “the number 1 indicator of parasites is actually an autoimmune condition”. This claim was made by Austin Lake, who introduced himself as a “functional medicine practitioner” in the video. Lake’s LinkedIn profile indicated that he holds a doctorate in physical therapy, but no qualifications to practice medicine.

The TikTok video was viewed more than 317,000 times and received more than 11,000 likes to date. A copy of the video was also uploaded by the Facebook page WOW PBX, which has more than 140,000 followers. The video received more than 57,000 views to date.

Lake also claimed that parasitic infections “stimulate Th2 immune cells which actually create antibodies” and “suppress Th1 cells which are a part of your innate immune system”.

However, Lake’s claim that autoimmunity in general can be traced back to parasitic infections isn’t substantiated by evidence, and his claims about Th1 and Th2 cells inaccurately describe immunological concepts, as we will explain below.

No evidence that parasitic infection is associated with autoimmunity in general

Broadly speaking, autoimmunity occurs when the body’s immune system mistakenly attacks normal cells in the body. However, autoimmune diseases don’t all manifest in the same way and the risk factors for developing one autoimmune disease aren’t always the same as for another. Lake named several conditions in his video, including multiple sclerosis, celiac disease, Hashimoto’s disease, and fibromyalgia, none of which are caused by parasites.

In multiple sclerosis (MS), the immune system attacks myelin, a fatty substance that coats and insulates neurons (nerve cells), permitting electrical signals to travel to and from the brain. This interferes with the transmission of electrical signals and can lead to a wide range of potential symptoms, including motor problems and vision problems. The U.S. National Institute of Neurological Disorders and Stroke states that known risk factors for MS are a genetic predisposition, infection by the Epstein-Barr virus, and a lack of vitamin D.

Interestingly, some research suggests that infection by certain parasites lowers the risk of MS instead of increasing it. The Multiple Sclerosis Association of America (MSAA) stated that “Parasites are a possible risk-reduction factor in the development of MS”:

“The parasites in this instance are ‘helminths,’ which refer to a wide variety of worms. Some are thought to be harmless, and many people had pinworms as children. Re