Safety and tolerability of experimental hookworm infection in humans with metabolic disease: study protocol for a phase 1b randomised controlled clinical trial.

BACKGROUND: Abdominal obesity and presence of the metabolic syndrome (MetS) significantly increase the risk of developing diseases such as Type 2 diabetes mellitus (T2DM) with escalating emergence of MetS and T2DM constituting a significant public health crisis worldwide. Lower prevalence of inflammatory and metabolic diseases such as T2DM in countries with higher incidences of helminth infections suggested a potential role for these parasites in the prevention and management of certain diseases. Recent studies confirmed the potential protective nature of helminth infection against MetS and T2DM via immunomodulation or, potentially, alteration of the intestinal microbiota. This Phase 1b safety and tolerability trial aims to assess the effect of inoculation with helminths on physical and metabolic parameters, immune responses, and the microbiome in otherwise healthy women and men. METHODS: Participants eligible for inclusion are adults aged 18-50 with central obesity and a minimum of one additional feature of MetS recruited from the local community with a recruitment target of 54. In a randomised, double-blind, placebo-controlled design, three groups will receive either 20 or 40 stage three larvae of the human hookworm Necator americanus or a placebo. Eligible participants will provide blood and faecal samples at their baseline and 6-monthly assessment visits for a total of 24 months with an optional extension to 36 months. During each scheduled visit, participants will also undergo a full physical examination and complete diet (PREDIMED), physical activity, and patient health (PHQ-9) questionnaires. Outcome measurements include tolerability and safety of infection with Necator americanus, changes in metabolic and immunological parameters, and changes in the composition of the faecal microbiome. DISCUSSION: Rising cost of healthcare associated with obesity-induced metabolic diseases urgently calls for new approaches in disease prevention. Findings from this trial will provide valuable information regarding the potential mechanisms by which hookworms, potentially via alterations in the microbiota, may positively influence metabolic health. TRIAL REGISTRATION: The protocol was registered on ANZCTR.org.au on 05 June 2017 with identifier ACTRN12617000818336. Alternatively, a Google search using the above trial registration number will yield a direct link to the trial protocol within the ANZCTR website.

Impact of experimental hookworm infection on the human gut microbiota.

The interactions between gastrointestinal parasitic helminths and commensal bacteria are likely to play a pivotal role in the establishment of host-parasite cross-talk, ultimately shaping the development of the intestinal immune system. However, little information is available on the impact of infections by gastrointestinal helminths on the bacterial communities inhabiting the human gut. We used 16S rRNA gene amplification and pyrosequencing to characterize, for the first time to our knowledge, the differences in composition and relative abundance of fecal microbial communities in human subjects prior to and following experimental infection with the blood-feeding intestinal hookworm, Necator americanus. Our data show that, although hookworm infection leads to a minor increase in microbial species richness, no detectable effect is observed on community structure, diversity or relative abundance of individual bacterial species.

Identificacion de especies de uncinaras necator americano y anquilostoma duodenale en el departamento de Cochabamba / Identification of uncinaria species; american necator-duodenale anquilostoma in the city of Cochabamba

La uncinariasis es una parasitosis causada por dos especies de nematodes, el Necator Americano y el Anquilostoma Duodenale, con una clinica que varia con la edad, alimentacion, raza, embarazo, intensidad de la infeccion y especie de uncinaria. Por no existir informacion respecto a la prevalencia de ambas especies en la patologia regional, es que se considero una prioridad la realizacion del presente trabajo. Las muestras procedentes de la provincia Chapare y Cercado fueron cultivadas de acuerdo a la tecnica de Harada-Mori para identificacion de larvas 3. Los resultados obtenidos de 50 muestras procesadas dieron cuenta de la presencia de solo larvas de A. Duodenale en el 100% de ellas. Teniendo en cuenta que la presencia de A. Duodenale confiere a un foco endemico mayor gravedad, nuestros resultados son una alerta a las autoridades de salud que tiene bajo su responsabilidad el control la profilaxis y educacion en nuestro medio