Human_infections_with_the_whipworm__Trichuris_trichiura__are_not_associated_with_alterations_in_the_faecal_microbiota_
Materials and Methods: We carried out the study in two rural communities  in Esmeraldas Province, Ecuador. School-age children were screened for  the presence of STH infections and allocated to one of 3 groups:  uninfected, T. trichiura only, and mixed infections with T. trichiura  and Ascaris lumbricoides. A sample of uninfected children and those with  T. trichiura infections only were treated with albendazole (800 mg/day  for 3 days) and ivermectin (single dose of 200 ug/kg), and stool samples  were collected 3 weeks post-treatment. Bacterial DNA was extracted using  the FastDNA Spin kit for soil, and bacterial community profiles were  studied by 454 pyrosequencing of 16S rRNA genes. This generated 999,796  sequences, which were processed and analysed using mothur.  Results: Microbiota analyses were done using stool samples from 97  children aged 8-14 years of whom 30 were not infected, 17 were infected  with T. trichiura alone, and 50 had mixed infections with both T.  trichiura and A. lumbricoides. Post-treatment samples were analyzed for  14 of the 17 children initially infected with T. trichiura alone and 21  of 30 uninfected children. Treatment resulted in 100% cure of STH  infections. Comparisons of the microbiota at different taxonomic levels  showed no statistically significant differences in composition between  uninfected children and those with T. trichiura infections. A surprising  finding was a decreased proportional abundance of a few bacterial genera  from the clostridia class of Firmicutes, in tandem with a reduced  overall bacterial diversity, among children with mixed infections  compared to either uninfected children or those with T. trichiura  infections only, indicating a specific effect of A. lumbricoides  infection on intestinal microbiota.  Anthelmintic treatment of children  with T. trichiura did not appear to alter composition of faecal microbiota.  Discussion: This is the first molecular study to analyse the effect of  whipworm infection on the human intestinal microbiota. Our data indicate  that T. trichiura infections alone have no effect on the faecal  microbiota of children living in endemic communities, but that A.  lumbricoides colonisation might be associated with a disturbed  microbiota. Our results also catalogue the microbiota that is present in  rural Ecuadorians, and indicate that there are differences between this  cohort and individuals from more urban, industrialised societies.