Hookworms: Can parasites improve your health?

Normal Curves: Sexy Science, Serious Statistics

What if you could treat your prediabetes with . . . worms? Regina and Kristin dive into a surprising early-phase clinical trial on hookworm therapy—that’s right, intentionally infecting yourself with parasitic worms—to treat metabolic conditions. They dig into the biological rationale (inflammation, abdominal fat, and gut immunology), the clever study design (hello, Tabasco sauce!), and the statistical chops behind this phase 1B trial (block randomization, missing data, and nonparametric hypothesis tests). Along the way, expect self-experimenting scientists, worm sex, poop analysis, and the world’s nerdiest aphrodisiac: a well-documented protocol.

Statistical topics

• Randomized controlled trial (RCT)
• Primary and secondary outcomes
• Placebos, placebo effect, and nocebo effect
• Block randomization
• Sample size
• Double-blinding
• Missing data protocols
• Reproducible research
• Nonparametric hypothesis testing
• Kruskal-Wallis test

Methodological morals

• “Walk before you can run. Invest in simple but high-quality Phase I clinical trials.”
• “When faced with small samples, you better rank and sum, baby.”

References

• Pierce DR, McDonald M, Merone L, et al. Effect of experimental hookworm infection on insulin resistance in people at risk of type 2 diabetes. Nat Commun. 2023;14(1):4503. doi:10.1038/s41467-023-40263-4
• Nuzzo, R. What Happens When Scientists Experiment on Themselves? Reader’s Digest. Updated April 16, 2016.
• Ethics of self-experimentation
• Helminthic Therapy Wiki
• Pritchard D. Worming your way to good health [video online]. TEDx Talks. Published November 19, 2013. https://www.youtube.com/watch?v=sm5DcdZbnGA
• Chapman PR, Giacomin P, Loukas A, McCarthy JS. Experimental human hookworm infection: a narrative historical review. PLoS Negl Trop Dis. 2021;15(12):e0009908. doi:10.1371/journal.pntd.0009908
• Sobotková K, Parker W, Levá J, Růžková J, Lukeš J, Jirků Pomajbíková K. Helminth Therapy - From the Parasite Perspective. Trends Parasitol. 2019;35(7):501-515. doi:10.1016/j.pt.2019.04.009
• Zatterale F, Longo M, Naderi J, et al. Chronic Adipose Tissue Inflammation Linking Obesity to Insulin Resistance and Type 2 Diabetes. Front Physiol. 2020;10:1607. Published 2020 Jan 29. doi:10.3389/fphys.2019.01607

Kristin and Regina’s online courses

Demystifying Data: A Modern Approach to Statistical Understanding

Clinical Trials: Design, Strategy, and Analysis

Medical Statistics Certificate Program

Writing in the Sciences

Epidemiology and Clinical Research Graduate Certificate Program

Program we teach in:

Epidemiology and Clinical Research Graduate Certificate Program

Find us on:

Kristin - LinkedIn & Twitter/X

Regina - LinkedIn & ReginaNuzzo.com

• (02:44) - What happens when scientists experiment on themselves
• (06:56) - Mail-order DIY helminthic therapy
• (09:26) - Hookworm biology
• (15:53) - Inflammation, abdominal fat, immune system, and hookworms
• (21:29) - Hookworm therapy clinical trial design
• (26:00) - Clinical trial phases deep dive
• (31:24) - Interesting placebos (sham surgeries and psychedelics)
• (37:33) - Excitement over hookworm trial open data and data protocols
• (44:45) - Hookworm trial results
• (48:48) - Mood and well-being with hookworms
• (53:26) - Effects of hookworms on weight
• (56:09) - Nonparametric tests and how they work
• (01:02:56) - What the participants did after the study
• (01:04:53) - Wrap-up