September 13, 2022 | Jerry Bergman

Does Co-Evolution Explain Helminth Therapy?


Co-Evolution theory fails, thus cannot be used to explain
the inverse correlation between parasitic helminth infection
and immune-mediated inflammatory diseases


by Jerry Bergman, PhD

— Using a term (‘co-evolution’) distracts from reasons why hookworms can treat immune diseases —

Epidemiology data confirms that inflammatory bowel diseases, such as irritable bowel syndrome, are increasingly common in the West. Furthermore, an inverse correlation exists between parasitic helminth infection, (flatworms, specifically hookworm), and the incidence of immune-mediated inflammatory diseases, including inflammatory bowel disease. In order to survive in their host, helminths use sophisticated mechanisms that suppress the host’s inflammation level. This suppression has the beneficial effect of preventing the onset of host inflammatory diseases.[1] The authors of a new research paper claim that this fact is due to a co-evolutionary

host–parasite relationship. Moreover, the relative safety and tolerability of experimental hookworm infection suggests that therapies based on these secreted proteins are likely to be safe and well-tolerated. Importantly, our approach employing in vivo administration of IVTRs to mice experiencing inducible colitis can be applied to drug discovery from the secretomes of other organisms, particularly where there are limited quantities of crude starting material. Hookworms secrete a broad arsenal of proteins into the gut, and our findings emphasize the diversity of structures that appear to converge upon a common theme of lipid and retinoid binding to suppress inflammation. This work highlights the value of parasitic helminths as both a source of next-generation biologics as well as a tool for druggable target/pathway discovery guided by millennia of host–parasite coevolution.[2]

They explain the origin of this fortunate event for the host using the theory of “co-evolution.”

—Ed. note: Co-evolution is the idea that one organism pressures another to evolve, starting a back-and-forth mutual pressure for each species to continually increase its survival chances at the expense of the other (an “evolutionary arms race”).

The assumption is that co-evolution is a valid explanation for the origin of the relationship that they have documented. It is widely recognized that Hookworm is an intestinal human parasite. The larvae and adult worms live in the small intestine and, as a result, can cause intestinal disease. These evolutionists claim that flatworms help prevent, or at least ameliorate, certain inflammatory diseases as a result of co-evolution.

Hookworm larva (Wikimedia Commons)


Other Examples of Natural-Source Drugs                                                                           

We often find similar fortunate co-existences in the natural world, most of which are obviously not examples of co-evolution. For example, the bark of the white willow tree contains salicin, a drug that has been widely used for many centuries to relieve pain. A related acetylated form produces aspirin (acetylsalicylic acid). No one claims that co-evolution has anything to do with this fortunate use of the white willow tree bark to treat pain.

The most well-known natural-source cancer drug in the United States, Taxol, is derived from Pacific yew tree bark (Taxus brevifolia). It is used in the treatment of breast, lung, and ovarian cancer, plus Kaposi’s sarcoma. Hundreds of additional examples of natural-source drugs exist.[3] Actually, plants have been the single most successful source of new medicines.[4] More research using flatworms and other invertebrates may well locate many other examples for medical treatments.

The Co-evolution Theory Born                                                                                                                    

Co-evolution theory was postulated to explain what Darwin called an “abominable mystery.” Specifically, he noted that flowers appeared and diversified relatively suddenly in the fossil record. How and why they had evolved so quickly created what Darwin described as a major problem for evolution.[5] He considered co-evolution the best explanation. Darwin first mentioned co-evolution in On the Origin of Species as a possible explanation for other major problems that his evolution theory could not explain. He developed the concept further in his book titled The Fertilization of Orchids published in 1862.[6]

Evolutionists claim many other traits arose by co-evolution.[7] One of the most obvious is the gonads of all sexual organisms. The male and female pair appear to be designed to be compatible, an obvious requirement for successful reproduction. Without successful reproduction, the organism would become extinct.[8] Evolutionists have attempted to explain their obvious fit by postulating that the male and female sex organs slowly co-evolved from asexual organisms. Co-evolution is required to explain the fact that the gonads would have to be compatible at each step of their evolution to be able to reproduce at every stage. If not, their evolution would be truncated, never making it to the sexual stage.

The Lethal Problem with Co-evolution Theory

Orthodox evolution teaches that the genetic source of the evolution of the gonads is random mutations. Most mutations, however, are near-neutral. These near-neutral mutations add up to produce genetic entropy and death, while almost all the rest are deleterious.

This theory of the co-evolution of sex is unfounded because no viable source of new genetic variation exists. The proposed source of genetic variation—mutations—are 99 percent deleterious. The theory for the origin of the genetic changes, according to Columbia University professor Jacques Barzun, (quoted by Time Magazine) was Darwin’s “discovery” of

“evolution by natural selection from accidental variations.” The dynamite, says Author Barzun, was in the phrase “from accidental variations.” Reason: it denied the role of God in the universe, ruled out a purpose in existence, [and] made men mere puppets of mechanical forces. Author Barzun confesses that his mind is still “paralyzed with enchantment” when he considers Darwin’s theory.[9]

Darwin’s view of “accidental variations,” or the modern view of “genetic variations produced by mutations” are both unable to produce the required changes in sex organs to evolve from being asexual to sexually compatible pairs at each step, eventually leading to modern humans. Now, evolution teaches, we are at the stage of perfection which has been stable for as long as humans have been humans.

The impossibility of random mutations to produce functional, cooperative organs is lethal for the co-evolution theory. It negates any attempt to use it to explain the negative relationship between the flat-worm presence in the small intestine and inflammatory bowel diseases.


Flatworms, to survive in the intestines, suppress the host’s immune system. This defense protection is not unusual. Most parasites use various mechanisms that allow them to live in their host. In the case of irritable bowel syndrome, the problem is an overactive immune system. Thus the presence of the hookworm can ameliorate the overactive immune system problem. This effect is not due to co-evolution but rather is another of many examples of a fortunate coincidence where one organism can have a beneficial effect on another organism.


[1] Ryan, Stephanie, et al. 2022. Novel anti-inflammatory biologics shaped by parasite–host coevolution. Proceedings of the National Academy of Sciences 119(36): e2202795119.

[2] Ryan, 2022, .p 7

[3] Cragg, Gordon M., and David J. 2005. “Plants as a source of anti-cancer agents.” Journal of Ethnopharmacology 100(1–2): 72–9, doi:10.1016/j.jep.2005.05.011. PMID 16009521.

[4] Shoeb, Mohammad. 2008. “Anticancer agents from medicinal plants.” Bangladesh Journal of Pharmacology 1(2): doi:10.3329/bjp.v1i2.486.

[5] Friedman, W.E. 2009. “The meaning of Darwin’s ‘abominable mystery.” American Journal of  Botany 96(1): 5–21, doi:10.3732/ajb.0800150, January.

[6] Darwin, Charles. 1862. On the Various Contrivances by Which British and Foreign Orchids Are Fertilized by Insects, and On the Good Effects of Intercrossing. London, England (UK): John Murray.

[7] Nuismer, Scott. 2017. Introduction to Coevolutionary Theory. New York, NY: W.F. Freeman.

[8] Cavalier-Smith, Thomas. 2010. “Origin of the Cell Nucleus, Mitosis and Sex: Roles of Intracellular Coevolution.” Biology Direct 5, no. 7 (February 4): DOI: 10.1186/1745-6150-5-7.

[9] From “The Struggle of Ideas” review of Darwin, Marx, Wagner. In Time (June 16, 1941).

Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,300 publications in 12 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,500 college libraries in 27 countries. So far over 80,000 copies of the 40 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.

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