The Effect of Gut Microbiome Composition on Human Immune Responses: An Exploration of Interference by Helminth Infections.

Soil-transmitted helminths have been shown to have the immune regulatory capacity, which they use to enhance their long term survival within their host. As these parasites reside in the gastrointestinal tract, they might modulate the immune system through altering the gut bacterial composition. Although the relationships between helminth infections or the microbiome with the immune system have been studied separately, their combined interactions are largely unknown.

Competing for blood: the ecology of parasite resource competition in human malaria-helminth co-infections.

Ecological theory suggests that co-infecting parasite species can interact within hosts directly, via host immunity and/or via resource competition. In mice, competition for red blood cells (RBCs) between malaria and bloodsucking helminths can regulate malaria population dynamics, but the importance of RBC competition in human hosts was unknown. We analysed infection density (i.

Longitudinal study of changes in γδ T cells and CD4 T cells upon asymptomatic malaria infection in Indonesian children.

Both γδ T cells and CD4 T cells have been implicated in immunity to malaria, but their association with natural gain or loss of infection has not been studied before. Therefore, we followed up asymptomatic children living in an area endemic for malaria in Indonesia for 21 months. The percentage of γδ T cells was related to both current and previous infection, with higher percentages in infected than uninfected children and declining after infections resolve.

Effect of Anthelmintic Treatment on Insulin Resistance: A Cluster-Randomized, Placebo-Controlled Trial in Indonesia.

Background: Emerging evidence suggests that helminth infections are associated with lower insulin resistance (IR). Current deworming programs might remove this helminth-associated protective effect. Therefore, we evaluated the anthelmintic treatment effect on changes in IR.

Community deworming alleviates geohelminth-induced immune hyporesponsiveness.

In cross-sectional studies, chronic helminth infections have been associated with immunological hyporesponsiveness that can affect responses to unrelated antigens. To study the immunological effects of deworming, we conducted a cluster-randomized, double-blind, placebo-controlled trial in Indonesia and assigned 954 households to receive albendazole or placebo once every 3 mo for 2 y. Helminth-specific and nonspecific whole-blood cytokine responses were assessed in 1,059 subjects of all ages, whereas phenotyping of regulatory molecules was undertaken in 121 school-aged children.

Heavy burden of intestinal parasite infections in Kalena Rongo village, a rural area in South West Sumba, eastern part of Indonesia: a cross sectional study.

Background: Intestinal parasitic infections (IPIs) are one of the major public health problems, especially in the rural area of developing countries with low socio-economic status and poor sanitation. The study was aimed to determine the prevalence of IPIs among the inhabitants of a rural area in South West Sumba, eastern part of Indonesia.

Methods: A cross-sectional study was done in Kalena Rongo village, South West Sumba in April 2014.

Infection with Soil-Transmitted Helminths Is Associated with Increased Insulin Sensitivity.

Objective: Given that helminth infections have been shown to improve insulin sensitivity in animal studies, which may be explained by beneficial effects on energy balance or by a shift in the immune system to an anti-inflammatory profile, we investigated whether soil-transmitted helminth (STH)-infected subjects are more insulin sensitive than STH-uninfected subjects.

Design: We performed a cross-sectional study on Flores island, Indonesia, an area with high prevalence of STH infections.

Methods: From 646 adults, stool samples were screened for Trichuris trichiura by microscopy and for Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, and Strongyloides stercoralis by qPCR.

Helminth infections and type 2 diabetes: a cluster-randomized placebo controlled SUGARSPIN trial in Nangapanda, Flores, Indonesia.

Background: Insulin resistance is a strong predictor of the development of type 2 diabetes mellitus. Chronic helminth infections might protect against insulin resistance via a caloric restriction state and indirectly via T-helper-2 polarization of the immune system. Therefore the elimination of helminths might remove this beneficial effect on insulin resistance.

Risk Factors Associated with the Development of Atopic Sensitization in Indonesia.

Background: The prevalence of allergic diseases has increased not only in high income but also in low-to-middle income countries. However, risk factors for their development are still not well established, particularly in the latter.

Objective: To assess prevalence and identify risk factors for sensitization to two major inhalant allergens among children from semi-urban and rural areas in Indonesia.

Epidemiology of Plasmodium infections in Flores Island, Indonesia using real-time PCR.

Background: DNA-based diagnostic methods have been shown to be highly sensitive and specific for the detection of malaria. An 18S-rRNA-based, real-time polymerase chain reaction (PCR) was used to determine the prevalence and intensity of Plasmodium infections on Flores Island, Indonesia.

Methods: Microscopy and real-time multiplex PCR for the detection of Plasmodium species was performed on blood samples collected in a population-based study in Nangapanda Flores Island, Indonesia.

The effect of three-monthly albendazole treatment on malarial parasitemia and allergy: a household-based cluster-randomized, double-blind, placebo-controlled trial.

Background: Helminth infections are proposed to have immunomodulatory activities affecting health outcomes either detrimentally or beneficially. We evaluated the effects of albendazole treatment, every three months for 21 months, on STH, malarial parasitemia and allergy.

Methods And Findings: A household-based cluster-randomized, double-blind, placebo-controlled trial was conducted in an area in Indonesia endemic for STH.

Asymptomatic plasmodial infection is associated with increased tumor necrosis factor receptor II-expressing regulatory T cells and suppressed type 2 immune responses.

Background: In malaria-endemic areas, a proportion of individuals becomes chronic carriers of parasites with few or no clinical signs. There is little information on cellular immune responses in asymptomatic parasite carriers.

Methods: In 80 schoolchildren residing in a malaria-endemic area of Flores Island, Indonesia, T-helper subsets, regulatory T-cell (Treg) frequencies, tumor necrosis factor receptor type II (TNFRII) expression on Tregs, and cytokine responses induced by Plasmodium falciparum-infected red blood cells (RBCs) were measured, and values for asymptomatic infected subjects were compared to those for uninfected controls.

Relationship between carotid intima media thickness and helminth infections on Flores Island, Indonesia.

Objective: To examine the association between helminth infections and atherosclerosis.

Background: Chronic helminth infection, which can lead to poor nutritional status and anti-inflammatory response, might protect against the development of atherosclerosis.

Methods: A cross-sectional study was performed in Flores, Indonesia, an area highly endemic for soil-transmitted helminths (STH).

Helminth infection in populations undergoing epidemiological transition: a friend or foe?

Helminth infections are highly prevalent in developing countries, especially in rural areas. With gradual development, there is a transition from living conditions that are dominated by infection, poor sanitation, manual labor, and traditional diet to a situation where burden of infections is reduced, infrastructure is improved, sedentary lifestyle dominates, and processed food forms a large proportion of the calorie intake. The combinations of some of the changes in lifestyle and environment are expected to result in alteration of the landscape of diseases, which will become dominated by non-communicable disorders.

Regulatory T cells in human lymphatic filariasis: stronger functional activity in microfilaremics.

Infection with filarial parasites is associated with T cell hyporesponsiveness, which is thought to be partly mediated by their ability to induce regulatory T cells (Tregs) during human infections. This study investigates the functional capacity of Tregs from different groups of filarial patients to suppress filaria-specific immune responses during human filariasis. Microfilaremic (MF), chronic pathology (CP) and uninfected endemic normal (EN) individuals were selected in an area endemic for Brugia timori in Flores island, Indonesia.

Blood pressure class and carotid artery intima-media thickness in a population at the secondary epidemiological transition.

Objectives: Data relating blood pressure (BP) class to subclinical organ damage are infrequently reported in populations with a traditional 'nonwestern' lifestyle. As the relevance of BP stratification to cardiovascular prognosis has not been elucidated in these low-income countries at the second epidemiological transition, we aimed to study the effect of BP class on carotid artery intima-media thickness (IMT) in Flores Island, Indonesia.

Methods: A cross-sectional study was performed in 476 inhabitants (men/women) of Flores.

A longitudinal study of allergy and intestinal helminth infections in semi urban and rural areas of Flores, Indonesia (ImmunoSPIN Study).

Background: The prevalence of asthma and atopic disease has been reported to be low in low income countries, however helminth infections are likely to be high among these communities. The question of whether helminth infections play a role in allergic diseases can best be addressed by intervention studies. None of the studies so far have been based on a large scale placebo-controlled trial.

Polyparasitism and its impact on the immune system.

Parasitic infections are common in many tropical and sub-tropical regions of the world and concomitant infection, polyparasitism, is the rule rather than the exception in such areas. At the immunological level, different parasites induce quite different responses characterised, for example, by protozoa that polarise responses towards Th1, whilst helminths are strong Th2 and regulatory T cell inducers. The question of how the co-existence of such parasites within the same host might influence the immunological responses to each species and, more importantly, whether such interactions affect resistance, susceptibility or clinical outcome, needs to be addressed in well-designed studies of sufficient power.

Does treatment of intestinal helminth infections influence malaria? Background and methodology of a longitudinal study of clinical, parasitological and immunological parameters in Nangapanda, Flores, Indonesia (ImmunoSPIN Study).

Background: Given that helminth infections are thought to have strong immunomodulatory activity, the question whether helminth infections might affect responses to malaria antigens needs to be addressed. Different cross-sectional studies using diverse methodologies have reported that helminth infections might either exacerbate or reduce the severity of malaria attacks. The same discrepancies have been reported for parasitemia.

Regulatory T cells in human geohelminth infection suppress immune responses to BCG and Plasmodium falciparum.

Chronic helminth infections induce T-cell hyporesponsiveness, which may affect immune responses to other pathogens or to vaccines. This study investigates the influence of Treg activity on proliferation and cytokine responses to BCG and Plasmodium falciparum-parasitized RBC in Indonesian schoolchildren. Geohelminth-infected children's in vitro T-cell proliferation to either BCG or pRBC was reduced compared to that of uninfected children.