Intestinal helminth infection and fecal microbiome profiling of intestinal helminthiasis in rural communities of Nan province, Thailand

Abstract

Gastrointestinal helminth infections are a global health problem that are particularly evident in underdeveloped and developing countries, including Thailand. Although the incidence of parasitic infections in Thailand has been declining, sporadic gastrointestinal infections still occur and remain an important health problem for rural communities. The intestinal tract is not only a microhabitat for various kinds of parasitic helminths, it also provides a habitat for microbiota, comprising a variety of symbiotic and commensal microorganisms, such as protozoa and bacteria. To investigate the intestinal-parasite status and associated microbiome in a rural area, the present study was conducted in Saen Thong Subdistrict, Tha Wang Pha District, Nan Province. 1,047 participants submitted stool samples for examination. 432 parasitepositive cases were identified, carrying at least one intestinal helminth species, yielding an overall 39.73% infection rate. The most prevalent parasite was the minute intestinal fluke, Haplorchis taichui (35.91%), followed by Taenia spp. (1.43%) and Ascaris lumbricoides (0.86%). Amplicon sequencing of 16S rRNA using an Illumina MiSeq platform was used to investigate the gut microbiome profiles of H. taichui infection, and compared with the negative group. After quality filtering of the obtained sequences, 60 bacterial operational taxonomic units (OTUs) were retained and assigned for taxonomic ranking. Prevotella copri was observed as a dominant bacterial OTU in the study population. Relative abundance of the three bacterial taxa: Ruminococcus, Roseburia faecis and Veillonella parvula, were significantly increased in the H. taichui-infected group. Alpha diversity analysis showed that the parasitenegative group presented higher bacterial diversity than the H. taichui-positive group. In addition, beta-diversity analysis of bacterial OTUs showed significantly different bacterial communities in the two groups. These results suggest that H. taichui infection potentially impacts microbiome profiles by reducing bacterial diversity and altering bacterial community structure in the gastrointestinal tract.