Age and Giardia intestinalis Infection Impact Canine Gut Microbiota

Abstract

Giardia intestinalis is a flagellated protozoan responsible for giardiosis (also called giardiasis in humans), the most prevalent and widespread parasitic infection in humans and mammals worldwide. The intestinal microbiota is highly diverse and any alteration in its composition may impact on the health of the host. While studies on the mouse model of giardiosis described the role of the gut microbiota in host susceptibility to infection by the parasite, little is known about the gut microbiota during natural infections in dogs and particularly in puppies. In this study, we monitored naturally G. intestinalis-infected puppies for 3 months and quantified cyst excretion every 2 weeks. All puppies remained subclinically infected during the sampling period as confirmed by fecal examination. In parallel, we performed 16S Illumina sequencing of fecal samples from the different time points to assess the impact of G. intestinalis infection on gut microbiota development of the puppies, as well as gut health markers of immunity such as fecal IgA and calprotectin. Sequencing results revealed that the canine fecal microbiota of Giardia-infected puppies becomes more complex and less diverse with increasing age. In addition, significant differences in the structure of the microbiota were observed between puppies with high and low Giardia cyst excretion. Chronic subclinical G. intestinalis infection appears to be associated with some detrimental structural changes in the gut microbiota. G. intestinalis-associated dysbiosis is characterized by an enrichment of facultative anaerobic, mucus-degrading, pro-inflammatory species and opportunistic pathogens, as well as a reduction of Lactobacillus johnsonii at specific time points. Calprotectin levels increased with age, suggesting the establishment of chronic low-grade inflammation in puppies. Further work is needed to demonstrate whether these alterations in the canine gut microbiota could lead to a dysbiosis-related disease, such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD).

Epilepsy and Giardia intestinalis infection impact the gut microbiome of canine species.

“…Giardia intestinalis is a agellated protozoan responsible for giardiasis, which is a parasitic infection in humans and mammals worldwide (25). When Giardia intestinalis infection appeared, the structure of the gut microbiota changed and was enriched by facultative anaerobic, mucus-degrading, pro-in ammatory species, and opportunistic pathogens (25). Additionally, this disease reduced Lactobacillus at speci c time points in canines (25).…”

Gut microbiota development in the growing dog: A dynamic process influenced by maternal, environmental and host factors

“…Naturally infected 9week-old puppies with high fecal load of Giardia intestinalis had a higher bacterial richness compared with low cyst load puppies. The opposite was observed in older puppies (about 22 weeks of age), with a reduced fecal bacterial richness of high cyst vs. low cyst load puppies (78). Moreover, G. intestinalis cyst shedding was positively associated with abundances of many bacterial communities observed in gut diseases in humans, such as Prevotella and Anaerobiospirillum succiniproducens; these bacteria induce the fragilisation of the mucus of the intestinal barrier.…”

“…Moreover, G. intestinalis cyst shedding was positively associated with abundances of many bacterial communities observed in gut diseases in humans, such as Prevotella and Anaerobiospirillum succiniproducens; these bacteria induce the fragilisation of the mucus of the intestinal barrier. This fragilisation makes it easier for Giardia intestinalis to cleave the barrier and allows more enteric pathogens to colonize the gut (78,116). Finally, in the 22 weeks old puppies, a high cyst load of Giardia was also correlated with a decrease in Lactobacillus johnsonii.…”

A zero-inflated Bayesian nonparametric approach for identifying differentially abundant taxa in multigroup microbiome data with covariates

“…The K(C − 1) = 12 vectors, each consisting of several regression coefficients, arise from a finite mixture model with M = 5 multivariate components. The colors represent the five mixture model components from which each β ku is drawn in (9). For example, in Figure 1, regression vectors β 13 , β 23 , and β 24 are all equal because they are drawn from the same finite mixture component (shown in blue).…”

“…Ruminococcus gnavus [9,14], and Alloprevotella [9] have known associations with inflammatory bowel disease in humans and dogs. The methods ANCOMBC, fitZIG, Maaslin2, DESeq2, and ZIBNP detected 9, 72, 7, 42, and 10 DA taxa, respectively.…”