Multiple sclerosis (MS) is a progressive autoimmune disease in which the myelin sheaths of nerves are targeted by the immune system. In addition to permanent nerve damage, over time this demyelination can lead to vision and motor control issues. Treatments usually rely on suppression of the immune system to slow progression, but these types of drugs can leave the body in a weakened state when fight infections. Since 2013 the prevalence of this disease has risen globally, and women are estimated to be 2-4 times more likely to develop MS than men (Walton, 2022). There are many proposed genetic and environmental interactions that may contribute to the onset of MS, but recent studies are beginning to investigate gut microbiota compositions as a means of mediating the progression of this disease and may even provide future alternative treatments that do not rely on immunosuppressive drugs.
A study published by Timothy Jenkins et al. expanded on
previous research that indicated that hookworms could be used to modulate immune
responses and promote a more stable and diverse gut microbiota in participants with
remitting MS. Volunteers were split into the treatment group that were infected
with hookworms and control groups that were given a placebo. At the end of the trial,
it was found the treatment group’s microbiota had an increase in the bacterial
species, Parabacteroides, and experience no detectable relapses of MS (Jenkins et al.,
2021). While this work is not conclusive, it may be a steppingstone toward
gaining a better understanding of human gut microbiota and how less invasive
hookworm derived products could be used in the future in autoimmune diseases.
But is it too alternative for Western
medicine?
The idea of treating an illness with parasites is bound to
invite the comparison of performing bloodletting with leeches, which is the
dated and often dangerous practice of attempting to draw out a disease and
balance the humors of the body via the extraction of blood. Today, disease etiology
is better understood, and bloodletting is considered to violate the ethos of do
no harm. Such an association may hamper the broad adoption of hookworms as a
means of modulating immune responses in autoimmune diseases and could be
further complicated by uncontrolled populations of hookworms within the treatment
group and potential spread of them outside of the treatment group. Perhaps one
day it will be looked upon like chemotherapy where some harm is accepted.
References:
1. 1.Jenkins, T. P., Pritchard, D. I., Tanasescu, R., Telford, G., Papaiakovou, M., Scotti, R., Cortés, A., Constantinescu, C. S., & Cantacessi, C. (2021). Experimental infection with the hookworm, Necator americanus, is associated with stable gut microbial diversity in human volunteers with relapsing multiple sclerosis. BMC Biology, 19(1). https://doi.org/10.1186/s12915-021-01003-6
2. 2.Walton, C., King, R., Rechtman, L., Kaye, W.,
Leray, E., Marrie, R. A., Robertson, N., La Rocca, N., Uitdehaag, B., van der
Mei, I., Wallin, M., Helme, A., Angood Napier, C., Rijke, N., & Baneke,
P. (2020). Rising prevalence of multiple sclerosis worldwide: Insights from the
atlas of MS, Third edition. Multiple Sclerosis Journal, 26(14), 1816–1821.
https://doi.org/10.1177/1352458520970841
Interesting post Isaac! As a Neuroscience major I have always been interested in MS. Do you think that it is acceptable to infect someone with hookworms to treat MS? What are some possible side effects of this study? I found another study where autologous hematopoietic stem cell transplantation was used to treat Multiple Sclerosis. This study has been conducted for over 20 years and found that the immune system resets for 6 years before the disease comes back again. One downside to this treatment is that it works best with those who are young (Muraro et al., 2017).
ReplyDeleteMuraro, P. A., Martin, R., Mancardi, G. L., Nicholas, R., Sormani, M. P., & Saccardi, R. (2017). Autologous haematopoietic stem cell transplantation for treatment of multiple sclerosis. Nature reviews. Neurology, 13(7), 391–405. https://doi.org/10.1038/nrneurol.2017.81
If I had a larger word count to work with I would have liked to dive into some of the broader ethical considerations and how exactly hookworms can be spread. It is pretty disgusting when you learn more about hookworms, but I think it would be easier to live with than permanent nerve damage. I am not sure about the efficacy as a treatment, but if I had MS I probably would be willing to do just about anything to slow progression. If you are interested in the topic and want to learn more there is a great podcast you should check out: https://radiolab.org/episodes/91951-an-update-on-hookworms
DeleteThis is great! Multiple sclerosis can be a very damaging disease to the long term health of those affected by it, and seeing a possible way to mitigate it in the future is amazing! You are right though, this treatment when looked at face value is ripe for misunderstanding and criticism, however, that is not to say that this couldn’t be a very real treatment in the future. Currently, the FDA is investigating and deliberating over the use of Fecal Matter Transport for patients (McSeveney, M. 2019). In the past, this treatment has seen great success with those who have not responded well to traditional treatments (xx). Just like this study, the investigation into FMTs at a glance could be wildly misinterpreted. The reason it is being taken so seriously is likely due to several studies backing up its advantageous effects on C.Diff. So, if this research can get more data proving that it is an effective method to mitigate MS, then in time it could be better accepted by the medical community and the general public.
ReplyDeleteSources:
McSeveney, M. (2019). FDA In Brief: FDA warns about potential risk of serious infections caused by multi-drug resistant organisms related to the investigational use of Fecal Microbiota for Transplantation. FDA. Retrieved from https://www.fda.gov/news-events/fda-brief/fda-brief-fda-warns-about-potential-risk-serious-infections-caused-multi-drug-resistant-organisms