Giardia duodenalis induces dysbiosis of human intestinal microbiota biofilms.

Giardia duodenalis induces dysbiosis of human intestinal microbiota biofilms. Int J Parasitol. 2017 Feb 22;: Authors: Beatty JK, Akierman SV, Motta JP, Muise S, Workentine ML, Harrison JJ, Bhargava A, Beck PL, Rioux KP, McKnight GW, Wallace JL, Buret AG Abstract Giardia duodenalis is a prevalent cause of acute diarrheal disease worldwide. However, recent outbreaks in Italy and Norway have revealed a link between giardiasis and the subsequent development of chronic post-infectious irritable bowel syndrome (PI-IBS). While the mechanisms underlying the causation of PI-IBS remain obscure, recent findings suggest that alterations in gut microbiota communities are linked to the pathophysiology of IBS. In the present study, we use a laboratory biofilm system to culture and enrich mucosal microbiota from human intestinal biopsies. Subsequently, we show that co-culture with Giardia induces disturbances in biofilm species composition and biofilm structure resulting in microbiota communities that are intrinsically dysbiotic - even after the clearance of Giardia. These microbiota abnormalities were mediated in part by secretory-excretory Giardia cysteine proteases. Using in vitro cell culture and germ-free murine infection models, we show that Giardia-induced disruptions of microbiota promote bacterial invasion, resulting in epithelial apoptosis, tight junctional disruption, and bacterial translocation across an intestinal epithelial barrier. Ad...
Source: International Journal for Parasitology - Category: Parasitology Authors: Tags: Int J Parasitol Source Type: research