Deprivation of dietary fiber enhances susceptibility of mice to cryptosporidiosis

Abstract

Based on our initial observations showing that mice consuming a probiotic product develop more severe cryptosporidiosis, we investigated the impact of other dietary interventions on the intracellular proliferation of Cryptosporidium parvum and C. tyzzeri in the mouse. Mice were orally infected with oocysts and parasite multiplication measured by quantifying fecal oocyst output. High-15 throughput sequencing of 16S ribosomal RNA amplicons was used to correlate oocyst output with diet and with the composition of the intestinal microbiota. On average, mice fed a diet without fiber (cellulose, pectin and inulin) developed more severe infections. As expected, a diet without fibers also significantly altered the fecal microbiota. Consistent with these observations, mice fed a prebiotic product sold for human consumption excreted significantly fewer oocysts. The fecal microbiota of mice 20 consuming no plant polysaccharides was characterized by a lower relative abundance of Bacteroidetes bacteria. Since bacterial metabolites play an important role in the physiology of intestinal enterocytes, we hypothesize based on these observations that the impact of diet on parasite proliferation is mediated primarily by the metabolic activity of the anaerobic microbiota, specifically by the effect of certain metabolites on the host. This model is consistent with the metabolic dependence of intracellular stages 25 of the parasite on the host cell. These observations underscore the potential of dietary interventions to alleviate the impact of cryptosporidiosis, particularly in infants at risk of recurrent enteric infections. AUTHOR SUMMARY 30The infection with Cryptosporidium parasite, a condition known as cryptosporidiosis, is a common cause of infant diarrhea in developing countries. We have previously shown that mice infected with C. parvum, one of the main cause of human cryptosporidiosis, develop a more severe infection if given probiotics. To investigate the mechanism of this effect, we fed mice prebiotics and diet lacking plant fiber. We found that fermentable fiber, whether administered as a prebiotic supplement or is part of the 35 diet, has a protective effect against cryptosporidiosis in mice. We also observed a significant association between the severity of infection and the composition of the gut microbiota. A significant inverse correlation was found between severity of cryptosporidiosis and the ratio between the abundance of bacteria belonging to the phylum Bacteroidetes and the abundance of Firmicute bacteria.This ratio is frequently viewed as a marker of a healthy microbiota. These results raise the possibility 40 that dietary interventions could be used to alleviate the impact of cryptosporidiosis. 45 as opportunistic pathogens in patients with AIDS, where cryptosporidiosis can lead to protracted diarrhea and wasting. Although immunocompetent patients heal spontaneously within a few weeks, recent studies in developing nations have pointed to Cryptosporidium as the second leading cause of infant diarrhea [2, 3]. The ...

Ecological relationships among habitat type, food nutrients, parasites and hormones in wild boar Sus scrofa during winter

“…The role of host–parasite interactions is important for the survival of animal populations and can influence nutritional intake (Tu et al 2007, Brima et al 2015, Oliveira et al 2019). For example, mice consuming high fat diets have greater resistance to parasites and higher survival (Brima et al 2015), and protein or fiber deficiency impairs the ability of mice to clear parasite infection (Tu et al 2007, Oliveira et al 2019).…”

“…The role of host–parasite interactions is important for the survival of animal populations and can influence nutritional intake (Tu et al 2007, Brima et al 2015, Oliveira et al 2019). For example, mice consuming high fat diets have greater resistance to parasites and higher survival (Brima et al 2015), and protein or fiber deficiency impairs the ability of mice to clear parasite infection (Tu et al 2007, Oliveira et al 2019). For wildlife, food availability and nutritional quality is different in different forest types and this variation may affect the food composition and nutritional intake by the consumer (Renner et al 2012, Navarro‐Castilla and Barja 2018).…”