Parasites in the Gut Help Develop a Healthy Immune System

Posted on June 24, 2010  Comments (4)

It has long been known that microbes in the gut help to develop a healthy immune system, hence the rise in popularity of probiotic yoghurts that encourage ‘friendly’ bacteria. But new research by Professors Richard Grencis and Ian Roberts shows that larger organisms such as parasitic worms are also essential in maintaining our bodily ‘ecosystem’. “The worms have been with us throughout our evolution and their presence, along with bacteria, in the ecosystem of the gut is important in the development of a functional immune system.”

Parasite Rex is a great book, I have written about previously looking at parasites and their affect on human health.

Professor Grencis adds: “If you look at the incidence of parasitic worm infection and compare it to the incidence of auto-immune disease and allergy, where the body’s immune system over-reacts and causes damage, they have little overlap. Clean places in the West, where parasites are eradicated, see problems caused by overactive immune systems. In the developing world, there is more parasitic worm infection but less auto-immune and allergic problems.

“We are not suggesting that people deliberately infect themselves with parasitic worms but we are saying that these larger pathogens make things that help our immune system. We have evolved with both the bugs and the worms and there are consequences of that interaction, so they are important to the development of our immune system.”

Whipworm, also known as Trichuris, is a very common type of parasitic worm and infects many species of animals including millions of humans. It has also been with us and animals throughout evolution. The parasites live in the large intestine, the very site containing the bulk of the intestinal bacteria.

Heavy infections of whipworm can cause bloody diarrhoea, with long-standing blood loss leading to iron-deficiency anaemia, and even rectal prolapse. But light infections have relatively few symptoms.

Professors Grencis and Roberts and their team at Manchester’s Faculty of Life Sciences investigated the establishment of Trichuris and found it is initiated by an interaction between gut bacteria and the parasite.

They further found that a broad range of gut bacteria were able to induce parasite hatching. In the case of Escherichia coli (E-coli), bacteria bound to specific sites on the egg and rapidly induce parasite hatching. With E-coli, hatching involved specific bacterial cell-surface structures known as fimbriae, which the bacteria normally use to attach to cells of the gut wall.

Importantly, the work also showed that the presence of worms and bacteria altered the immune responses in a way that is likely to protect ourselves, the bacteria and the worms.

Intestinal roundworm parasites are one of the most common types of infection worldwide, although in humans increased hygiene has reduced infection in many countries. High level infections by these parasites can cause disease, but the natural situation is the presence of relatively low levels of infection. The team’s work suggests that in addition to bacterial microflora, the natural state of affairs of our intestines may well be the presence of larger organisms, the parasitic roundworms, and that complex and subtle interactions between these different types of organism have evolved to provide an efficient and beneficial ecosystem for all concerned.

Professor Grencis adds: “The gut and its inhabitants should be considered a complex ecosystem, not only involving bacteria but also parasites, not just sitting together but interacting.”

Related: Parasitic Worms Reduce Hay Fever SymptomsHow Humans Evolved AllergiesForeign Cells Outnumber Human Cells in Our BodiesBeneficial Bacteria

4 Responses to “Parasites in the Gut Help Develop a Healthy Immune System”

  1. Anonymous
    June 25th, 2010 @ 5:23 am

    yes some parasites in the body helps a lot in maintaining a balance immune system but it should always be balance..I know some parasites helps in body metabolism and digestion.

  2. Brian
    June 27th, 2010 @ 10:36 am

    Bacteria in the gut have long been known to be beneficial to the immune system, but the fact that worms (which are usually thought as completely undesirable) can have the same characteristics is really interesting.

    This shows that our conceptions about infectious pathogens is very superficial… The fact is, most so-called “pathogens” become pathogens only on unbalanced terrains, like weeds or pests in a chemically-treated garden. For instance, half of humans are infected with cytomegalovirus, but this doesn’t create any problem except for some people with very weakened immune systems.

    The concepts of ecology and ecosystems are probably the number one approaches that should be followed if we want to have a real understanding of disease and health in humans, but also in any living entity. These concepts are based on the fact that what matters most is the natural equilibrium between components, and not the peculiarities of a given component isolated from the rest. This global approach is probably what is missing most in modern medicine – although it seems to be slowly changing, fortunately!

  3. Video showing malaria breaking into cell » Curious Cat Science and Engineering Blog
    January 20th, 2011 @ 7:06 pm

    […] Parasites in the Gut Help Develop a Healthy Immune System – Parasite Rex Posted by curiouscat Categories: Health Care, Life Science, […]

  4. Youyou Tu: The First Chinese Woman to Win a Nobel Prize » Curious Cat Science and Engineering Blog
    October 17th, 2015 @ 8:48 am

    The Nobel Prize in Physiology or Medicine 2015 was divided, one half jointly to William C. Campbell (born Ireland, now USA) and Satoshi Ōmura (Japan) “for their discoveries concerning a novel therapy against infections caused by roundworm parasites” and the other half to Youyou Tu (China) “for her discoveries concerning a novel therapy against Malaria”…

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