Helminth therapy is by far one of the most effective treatments that we have seen in the treatment of autoimmune diseases, including PANS/PANDAS and Autism Spectrum Disorder (ASD). In fact, we often refer to the therapy as a possible “game changer” for many of our children. In my practice, we do not order or administer more invasive immunotherapy interventions (such as IVIG, plasmapheresis, or rituximab) because we typically do not need to; helminth therapy has been so effective, most of our patients do not need to seek out other treatments.

I will say that the biggest hurdle to helminth therapy is simply wrapping your head around the idea of putting an organism in your body to treat illness. Admittedly, it is not a common intervention, and can take some persuasion for most families! Still, if you can get over the “ick” factor with helminth therapy, I strongly recommend it as an easy, safe, and non-invasive treatment that could absolutely be a “game changer” for you or your child.


Helminths, also known as HDCs (Hymenolepis diminuta cysticercoids), are mutualist organisms in the form of microscopic eggs, interacting with their host to both parties’ benefit. This is different than the actions of a parasite, as parasitic interactions occur when one organism (the parasite) benefits and the host is harmed.

In an overly simplistic explanation, rats are the host of adult tapeworms, which do not cause disease in the animal (hence the mutualist relationship). The eggs of these tapeworms are excreted in the feces of the rat, and grain beetles eat these eggs. Scientists can dissect grain beetles to harvest the HDCs for clinical use.

Here is a picture I took of HDCs under a microscope when in a lab harvesting them. Aren’t they beautiful?

Helminth's under a microscope


Helminths affect the body’s autoimmune response, and the higher prevalence of autoimmunity in modern times can best be summed up by the “Hygiene Hypothesis.” It is estimated that 20% of children are diagnosed with chronic illness, and the rates continue to rise (Blackwell et al., Pediatrics, 2019). Some reports estimate that one in every two individuals are diagnosed with a chronic illness, many of which are autoimmune diseases. The Hygiene Hypothesis, first proposed by David Strachan in 1989, intended to explain the increasing rates of asthma in highly developed countries. He observed increased allergies in firstborn children, and postulated that this is because they are exposed much later to infections brought into the home, versus earlier exposure to their younger siblings. He suggested that contact with a high number of infections early in life could appropriately train the adaptive immune system, and that significant changes in human living standards and the improvement of sanitary conditions meant that people had less exposure to infection in general, but especially in childhood. This in turn causes an impaired, hyper reactive immune response to environmental triggers (Strachan, BMJ, 1989).

The “Hygiene Hypothesis of Autoimmunity,” proposed in the early 2000s, states that the decreasing incidence of infections in western countries and now in developing countries corresponds to the increasing incidence of both autoimmune and allergic diseases (Jean-Francois Bach, N Engl J Med, 2002). This is because some infectious agents – notably, those that co-evolved with us – are able to protect against a large spectrum of immune-related disorders.

Figure 1

Alterations of microbiota are also responsible for the increase in autoimmunity. The gut microbiome of the general population has been altered because of the increase in births by Caesarean section, which has been linked to increased allergic diseases (Thavagnanam et al, Clin Exp Allergy, 2008), and the increase in formula feeding over breastfeeding (Charbonneau et al, Cell, 2016). Smaller family size tends to have a negative impact as well, as studies have shown that children from large families are at lower risk of developing allergies (Penders et al, Gut Microbes, 2014). Where you live can influence the diversity of your microbiota, too. Studies in Finland show that living close to green space and agriculture, rather than close to a town, increases biodiversity.

Furthermore, the overuse of antibiotics has a detrimental impact on the gut, and the damage sustained by prolonged antibiotic use can be transmitted to future generations (Sonnenburg et al, Nature, 2016). The good news is that pets can have a beneficial impact on the diversity of the microbiome, as people share their microbiota with their dogs, which greatly increases the microbial biodiversity of the home (Song et al, elife, 2013). Not only does Dogtor Ed help with my mental health by providing me with such joy, he is also strengthening the microbiome of my family! #dogsaresuperheroes

Unfortunately, we humans have altered our microbiota to such an extent that the immune system is quite susceptible to environmental factors that can lead to autoimmunity. This is where HDCs can shine. William Parker, MD, refers to HDCs as an “exercise for the immune system,” and their ability to positively impact the immune system is quite impressive.

Helminth therapy works by reconstituting our microbiome by reintroducing Hymenolepis diminuta cysticercoids to the human biome. HDCs were part of our normal microbiome before we became an industrialized society, and are still prevalent in the microbiome of citizens in other countries (where there is less autoimmune disease as a result–see photos below). The decrease prevalence of autoimmunity in these countries is a direct result of HDCs, which we have found are Th2-inducing organisms, and are able to regulate and control an overactive Th1 cytokine response (Coakley, et al, Molecular and Biochemical Parasitology, 2016). As a result, the presence of HDCs in the microbiome help the gut to remain in homeostasis, or balance, and decrease the likelihood of hyper reactive immune or inflammatory response.

Map of Helminths infestation


Helminth Therapy is simple, and involves drinking ~1 ml of a salty liquid every 3 weeks. This intervention is very easy to implement in even the most restrictive and picky children, as many parents will add it to a liquid that they know their child will drink completely.

HDC therapy intervention is very safe, and risk of infestation is extremely small, as long as you or your child are not constipated and not on any immunosuppressive medications. Helminths are unique in that they do not breach the barrier of the GI tract, unlike hookworms or whipworms.

When we implement this intervention in the office, we always start slowly, building up tolerance over a few months up to the dosage determined by your care team. We then recommend continued treatment at the appropriate dosage for at least three months. When this intervention is first implemented and when increasing the dosage, it is possible that there will be an increase in symptoms for a short period of time. This is similar to a “die off” presentation or Herxheimer reaction, but it is caused by the body’s response to increased histamine and inflammation from the HDCs. If this occurs, discuss with your provider about implementing an antihistamine or anti-inflammatory protocol to manage the reaction, and be assured that this is a temporary issue and a part of the healing process.

I hope that you have found this post helpful and feel comfortable trying HDCs if they are recommended by your healthcare provider. If you are looking for a doctor familiar with helminth therapy, and are interested in becoming a patient of the practice, please visit my website at www.lindseywellsnd.com or call the office at (203) 834-2813.


For more information regarding the research on helminth therapy visit: