Helminths and the gut microbiota
Helminths and bacteria form a complex, interactive ecosystem involved in immunity
It is like a three-legged stool - the microbes, worms and immune system regulate each other. 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. (Prof Ian Roberts, Manchester University) [2]
Our findings uncover the intricate interactions of the tripartite partnership within the helminth–microbiome–host complex. It is evident that the ability of the helminth to modulate the immune system depends, at least in part, on the intestinal microflora, and this interaction in turn may impact its protective effect in inflammatory disease. [5]
Scientific papers and articles relating to helminths and the gut microbiota[edit | edit source]
2023[edit | edit source]
- The results of this study demonstrate that helminths release molecules via their excretory-secretory pathway that have broad-spectrum bactericidal activity.
- Interaction between tissue-dwelling helminth and the gut microbiota drives mucosal immunoregulation -- Full text
- A tissue-dwelling helminth was shown to drive expansions of host colonic Tregs through the gut microbiota, with an increase in L. reuteri and short-chain fatty acids, suggesting that the gut microbiome serves as a critical component of anti-inflammation effects, even with therapy using an extraintestinal helminth.
2022[edit | edit source]
- Clostridia isolated from helminth-colonized humans promote the life cycle of Trichuris species -- Full text
- Human microbiome members, Peptostreptococcaceae, a family of Gram-positive bacteria in the class Clostridia, have been found to display a superior capacity to promote the life cycle of whipworm species, including hatching of eggs from Trichuris trichiura (TTO).
- Excretory-secretory products from the brown stomach worm, Teladorsagia circumcincta, exert antimicrobial activity in in vitro growth assays -- Full text
- "The data indicate that helminth infections… altered the abundance of specific bacterial taxa in the host gut but not overall bacterial diversity. In contrast, the saliva microbiota displayed both altered bacterial richness and abundance during active helminth infections."
- Unbalanced relationships: insights into the interaction between gut microbiota, geohelminths, and schistosomiasis -- Full text | PDF
- "While most of (the helminths) (e.g., Ascaris sp. and Trichuris sp.) can modify the gut microbiota, others (such as N. americanus) appear not to influence it."
2021[edit | edit source]
- This study provides strong evidence that helminth infection dynamically shifts the intestinal microbiome structure, with those helminths found in the large intestine, such as Enterobius vermicularis and Trichuris trichiura, showing the greatest influence on microbiome composition.
- Cooperation between host immunity and the gut bacteria is essential for helminth-evoked suppression of colitis -- Full text
- “Extrapolating from this model system, we suggest that for helminth therapy to be beneficial it needs to be coupled to a precise knowledge of the immunological profile of the malady to be treated and the composition of the patients’ microbiome. Furthermore, we speculate that reduced efficacy of helminth therapy could be enhanced by combination with a probiotic matched to compensate for dysbiosis in a particular individual.”
- Exposure to Parasitic Protists and Helminths Changes the Intestinal Community Structure of Bacterial Communities in a Cohort of Mother-Child Binomials from a Semirural Setting in Mexico -- Full text | PDF
- Supports previous evidence suggesting that the presence of intestinal parasites is linked to strong bacterial microbiota community changes.
- Proposes that microbiota-derived extracellular vesicles might be key players in host-helminth-microbiome crosstalk.
- Experimental infection with the hookworm, Necator americanus, is associated with stable gut microbial diversity in human volunteers with relapsing multiple sclerosis -- Full text | PDF
- This study reveals data linking colonisation by the hookworm, NA, with modulation of host bacterial microbiota composition.
- Evolution of bacteria in the human gut in response to changing environments: An invisible player in the game of health -- Full text | PDF
- Factors such as the widespread use of antibiotics, chronic inflammation and the loss of complex eukaryotic symbionts such as helminths, cause dramatic alterations in the gut ecosystem and drive rapid change in microorganisms via Darwinian evolution to create functionally distinct bacteria that may potentially have properties of pathogens but yet are difficult to distinguish from their benign predecessors.
- Helminth Interactions with Bacteria in the Host Gut Are Essential for Its Immunomodulatory Effect -- Full text
- “Our findings uncover the intricate interactions of the tripartite partnership within the helminth–microbiome–host complex. It is evident that the ability of the helminth to modulate the immune system depends, at least in part, on the intestinal microflora, and this interaction in turn may impact its protective effect in inflammatory disease.”
- "These results suggest that Schistosoma japonicum infection has a significant effect on microbiome composition characterized by a higher abundance of the TM7 phylum and development of a Bacteroides enterotype."
2020[edit | edit source]
- Helminth-induced and Th2-dependent Alterations of the Gut Microbiota Attenuate Obesity Caused by High Fat Diet — PDF
- Lifestyle and the Presence of Helminths Is Associated With Gut Microbiome Composition in Cameroonians -- Full text | PDF
- Dietary Inulin and Trichuris suis Infection Promote Beneficial Bacteria Throughout the Porcine Gut -- Full text | PDF
2019[edit | edit source]
- Linking the effects of helminth infection, diet and the gut microbiota with human whole-blood signatures -- Full text
- There is considerable interplay between helminths, micronutrients and the microbiota on the regulation of immune responses in humans.
- The Effect of Gut Microbiome Composition on Human Immune Responses: An Exploration of Interference by Helminth Infections -- Full text | PDF
- The modulation of the immune system by helminths involves an interplay with several other factors, such as diet and environment, in addition to being influenced by the composition of the gut microbiome.
- This work provides conclusive evidence that intestinal helminths can impact the mammalian intestinal microbiome, and indicates that helminth-induced changes can occur at regions distant from the site of parasite infection.
- The interplay of type 2 immunity, helminth infection and the microbiota in regulating metabolism -- Full text | PDF
- Contribution of the Gut Microbiota in P28GST-Mediated Anti-Inflammatory Effects: Experimental and Clinical Insights -- Full text
- Suppression of obesity by an intestinal helminth through interactions with intestinal microbiota -- PDF (Also reported by EurekAlert: Intestinal helminths boost fat burning: Japanese investigators show how)
- Helminths prevented weight gain in laboratory mice on a high-fat diet. They did this by boosting populations of bacteria - notably certain species of Bacillus and Escherichia - that produce compounds which trigger increased energy consumption.
- The Impact of Anthelmintic Treatment on Human Gut Microbiota Based on Cross-Sectional and Pre- and Postdeworming Comparisons in Western Kenya -- Full text | PDF
- This study contributes to understanding of how microbial communities differ between individuals infected by soil-transmitted helminths and those who are uninfected.
- In a very detailed “Helminths” section (pages 26-35), this paper discusses evidence that host-associated microbes may impact helminth infection success, that helminth colonization may impact the diversity and composition of the gut microbiome, and that both can have impacts on immune function.
2018[edit | edit source]
- Mucosal Barrier and Th2 Immune Responses Are Enhanced by Dietary Inulin in Pigs Infected With Trichuris suis -- Full text | PDF
- Trichuris suis and dietary inulin co-operatively mediate beneficial changes in microbiota composition in pigs to enhance anti-inflammatory immune responses.
- A comprehensive analysis of the faecal microbiome and metabolome of Strongyloides stercoralis infected volunteers from a non-endemic area -- Full text | PDF
- Monospecific, chronic infection with the helminth, S. stercoralis, were found to be associated with global shifts in the composition of the human faecal microbiota, as well as subtle changes in faecal metabolic profiles.
- The Intestinal Roundworm Ascaris suum Releases Antimicrobial Factors Which Interfere With Bacterial Growth and Biofilm Formation -- Full text | PDF
- Characteristics of the bacterial microbiome in association with common intestinal parasites in irritable bowel syndrome -- Full text | PDF
- While this study focused on the parasites, Dientamoeba fragilis and Blastocystis, rather than helminths, its conclusions are nevertheless interesting.
- “Presence of parasites was associated to a rich and diverse microbiome in healthy controls and individuals with unspecific GI symptoms… Observations of parasite colonization being associated to healthy features of the gut microbiome should differentiate our view of intestinal parasites beyond the focus on pathogenicity.”
- Classic Models for New Perspectives: Delving into Helminth–Microbiota–Immune System Interactions
- Helminth–Bacterial Interactions: Cause and Consequence
- Parasite-Microbiota Interactions With the Vertebrate Gut: Synthesis Through an Ecological Lens -- Full text | PDF
- This is a good review of studies investigating the interactions of the intestinal microbiota, gut parasites and their host, and how these interactions may affect the overall health of the host.
- The therapeutic prospect of crosstalk between prokaryotic and eukaryotic organisms in the human gut
- Associations between Gut Microbiota and Common Luminal Intestinal Parasites
- Manipulation of host and parasite microbiotas: Survival strategies during chronic nematode infection -- Full text | PDF
- The eggs of T. muris that hatch in sterile conditions are free from bacteria.
- T. muris maintains its own distinct microbiota, comprising bacteria selected from the intestine of its host, regardless of the surrounding bacterial populations.
- Infection with T. muris causes significant restructuring of the host cecal microbiota and a reduction in total bacterial diversity.
- T. muris-induced changes in the host microbiota suppresses subsequent parasite egg hatching, consequently controlling parasite numbers in the infected host intestine independently of the host adaptive immune system.
- Differential human gut microbiome assemblages during soil-transmitted helminth infections in Indonesia and Liberia -- Full text | PDF
- The impact of a helminth-modified microbiome on host immunity
2017[edit | edit source]
- Infections by human gastrointestinal helminths are associated with changes in faecal microbiota diversity and composition
- Parasite-microbiota interactions potentially affect intestinal communities in wild mammals
- Reciprocal Interactions between Nematodes and Their Microbial Environments
- Highlights findings concerning responses to bacterial stimuli, antimicrobial peptides and the reciprocal influences between nematodes and their environmental bacteria. Also discussed are the microbiota of nematodes and alterations in the intestinal microbiota of mammalian hosts by helminth infections.
- Enteric helminth-induced type I interferon signaling protects against pulmonary virus infection through interaction with the microbiota -- Full text | PDF
- Demonstrates that an intestinal helminth infection can have remote protective antiviral effects in the lung through induction of a microbiota-dependent type I interferon response.
- Gut microbiota disturbance during helminth infection: can it affect cognition and behaviour of children? -- Full text | PDF
2016[edit | edit source]
- Macrobiota - helminths as active participants and partners of the microbiota in host intestinal homeostasis -- Full text | PDF
- Helminth infection protects mice deficient in the Crohn’s disease susceptibility gene Nod2 from intestinal abnormalities by inhibiting colonization with an inflammatory Bacteroides species.
- Discusses at length the interrelationships between intestinal helminths and microbiota, in both humans and mice, and highlights the fact that certain microbiota species can determine the outcomes of helminth infection.
"... although intestinal helminths are generally accepted to possess potent immuno-modulatory activity, it is unknown whether this capacity requires interactions with intestinal bacteria. We propose that this 'ménage à trois' situation is likely to have exerted a strong selective pressure on the development of our metabolic and immune systems."
- Discusses at length the interrelationships between intestinal helminths and microbiota, in both humans and mice, and highlights the fact that certain microbiota species can determine the outcomes of helminth infection.
2015[edit | edit source]
- Worming Their Way into the Picture: Microbiota Help Helminths Modulate Host Immunity -- Full text | PDF
- Helminths and bacterial microbiota act in bi-directional synergy to modulate immune responses.
- Unraveling the Hygiene Hypothesis of helminthes and autoimmunity: origins, pathophysiology, and clinical applications -- Full text | PDF
- Helminths move the balance of the intestinal flora to favour “probiotic” microorganisms.
- Cohabitation in the Intestine: Interactions among Helminth Parasites, Bacterial Microbiota, and Host Immunity -- Full text | PDF
- The Intestinal Microbiota Contributes to the Ability of Helminths to Modulate Allergic Inflammation -- Full text | PDF
- Experimental hookworm infection and escalating gluten challenges are associated with increased microbial richness in celiac subjects -- Full text|PDF
- "Notably, we observed a significant increase in microbial species richness over the course of the trial, which could represent a potential mechanism by which hookworms can regulate gluten-induced inflammation and maintain intestinal immune homeostasis."
- Type 2 immunity-dependent reduction of segmented filamentous bacteria in mice infected with the helminthic parasite Nippostrongylus brasiliensis -- Full text | PDF
- "Dynamic interactions between the host and gastrointestinal microbiota play an important role for local and systemic immune homeostasis."
- "In general, helminth presence is linked with high microbiota diversity, which may confer health benefits to the host… The most pronounced helminth-microbiota association was between the presence of tapeworms in the small intestine and increased S24-7 (Bacteroidetes) family in the stomach."
- "In this article, we review recent progress in the elucidation of host-parasite-microbiota interactions in both animal models of chronic inflammation and humans, and provide a working hypothesis of the role of the gut microbiota in helminth-induced suppression of inflammation."
- Chronic Trichuris muris Infection Decreases Diversity of the Intestinal Microbiota and Concomitantly Increases the Abundance of Lactobacilli -- Full text | PDF
- Alteration of the rat cecal microbiome during colonization with the helminth Hymenolepis diminuta -- Full text | PDF
- Colonisation by Hymenolepis diminuta led to several changes in rat cecal microbiome that were mostly within the Firmicutes phylum, involved about 20% of the total bacteria, and entailed a shift from Bacilli to Clostridia species.
- Chronic Trichuris muris Infection in C57BL/6 Mice Causes Significant Changes in Host Microbiota and Metabolome: Effects Reversed by Pathogen Clearance -- Full text | PDF
- "... infection of T. muris causes a significant and substantial impact on intestinal microbiota and digestive function of mice with affects in long term immune regulation."
2014[edit | edit source]
- Virus-helminth coinfection reveals a microbiota-independent mechanism of immunomodulation -- Full text | PDF
- “… helminth-induced immunomodulation occurs independently of changes in the microbiota but is dependent on Ym1.”
- Discusses changes occurring in the microbiota upon helminth infection and the underlying mechanisms leading to these changes.
- Helminth colonization is associated with increased diversity of the gut microbiota -- Full text | PDF
- Helminths may have an impact on the diversity, bacterial community structure and function of the gut microbiota.
- Effect of Bifidobacterium animalis on mice infected with Strongyloides venezuelensis -- Full text | PDF
- The bacterium, B. animalis, significantly decreased the S. venezuelensis worm burden and egg output.
2013[edit | edit source]
- A role for IL-22 in the relationship between intestinal helminths, gut microbiota and mucosal immunity -- Full text | PDF
- "… by inducing an immune response that includes IL-22, intestinal helminths may enhance the mucosal barrier function of the intestinal epithelium. This may restore the mucosal microbiota populations from dysbiosis associated with colitis and improve intestinal homeostasis."
2012[edit | edit source]
- Alterations in the porcine colon microbiota induced by the gastrointestinal nematode Trichuris suis -- Full text | PDF
- Therapeutic helminth infection of macaques with idiopathic chronic diarrhea alters the inflammatory signature and mucosal microbiota of the colon -- Full text | PDF
- Whipworms can restore the balance of gut bacterial communities in sick monkeys.
2011[edit | edit source]
- Changes in the mucosal barrier during acute and chronic Trichuris muris infection -- Full text | PDF
2010[edit | edit source]
- Alteration of the murine gut microbiota during infection with the parasitic helminth Heligmosomoides polygyrus -- Full text | PDF
- Helminth infection shifts the composition of intestinal bacteria.
- Exploitation of the intestinal microflora by the parasitic nematode Trichuris muris -- Full text | PDF
- "It is like a three-legged stool - the microbes, worms and immune system regulate each other. 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."