Gut microbiota composition does not associate with toxoplasma infection in rats

Abstract

Toxoplasma infection in intermediate host species closely associates with inflammation. This association has led to suggestions that the behavioural changes associated with infection may be indirectly driven by the resulting sustained inflammation rather than a direct behavioural manipulation by the parasite. If this is correct, sustained inflammation in chronically infected rodents should present as widespread differences in the gastrointestinal microbiota due to the dependency between the composition of these microbiota and sustained inflammation. We conducted a randomized controlled experiment in rats that were assigned to a Toxoplasma‐treatment, placebo‐treatment or negative control group. We euthanised rats during the chronic phase of infection, collected their caecal stool samples and sequenced the V3‐V4 region of the 16S rRNA gene to characterize the bacterial community in these samples. Toxoplasma infection did not induce widespread differences in the bacterial community composition of the gastrointestinal tract of rats. Rather, we found sex differences in the bacterial community composition of rats. We conclude that it is unlikely that sustained inflammation is the mechanism driving the highly specific behavioural changes observed in Toxoplasma‐positive rats.

Changes of gut microbiota structure in rats infected with Toxoplasma gondii

“…Our results were in contrast with the findings by Taggart et al (2022), who reported that the chronic infection of T. gondii did not change the gut microbiota structure of Wistar Hannover rats and concluded that chronical infection may not cause persistent inflammation in rats. The differences for these results may be due to a variety of experimental designs.…”

Microbiome Responses to Fecal Microbiota Transplantation in Cats with Chronic Digestive Issues

“…Although not an exact proxy, the fecal microbiome reflects the trillions of microbes that reside in the gastrointestinal tract; microbes that collectively contribute to host digestion, immunity and pathogen defense, and intestinal barrier homeostasis [ 1 ]. While the composition of the fecal microbiome is highly dynamic and can correlate with a range of host factors including age [ 2 , 3 ], sex [ 4 ], body condition [ 5 ], diet [ 6 , 7 ], and antibiotic use [ 8 ], more persistent changes in composition have also been associated with disease and infections [ 9 , 10 ]. Compared to their healthy counterparts, the fecal microbiome of animals with a disease or infection may have reduced microbial diversity [ 11 ], decreased abundances of functionally important microbes like fermentative or short-chain fatty acid (SCFA)-producing bacteria [ 12 ], or elevated abundances of pathogenic taxa [ 13 , 14 ].…”