ena-STUDY-TUFTS UNIVERSITY-31-03-2019-03:02:10:151-194
Deprivation of dietary fiber enhances susceptibility of mice to cryptosporidiosis
Based on our initial observations showing that mice consuming a probiotics product develop more severe cryptosporidiosis, we investigated the impact of dietary fibers on the 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-throughput sequencing of 16S ribosomal RNA amplicons was used to characterize the impact of the infection and diet on the intestinal microbiota. On average, mice fed a diet without fiber (cellulose, pectin and inulin) developed more severe infections. 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 in the feces. The fecal microbiota of mice consuming no plant polysaccharides was characterized by a decreased relative abundance of Bacteroidetes. Although a direct effect of diet on C. parvum infected intestinal enterocytes cannot be ruled out, our results indicate that dietary fiber deprivation increases the susceptibility to severe cryptosporidiosis by modifying the metabolic activity of the intestinal bacteria. These observations underscore the potential of the bacterial metabolism to aleviate the impact of cryptosporidiosis, particularly in at-risk infants living in environments were enteric pathogens are prevalent.
Based on our initial observations showing that mice consuming a probiotics product develop more severe cryptosporidiosis, we investigated the impact of dietary fibers on the 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-throughput sequencing of 16S ribosomal RNA amplicons was used to characterize the impact of the infection and diet on the intestinal microbiota. On average, mice fed a diet without fiber (cellulose, pectin and inulin) developed more severe infections. 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 in the feces. The fecal microbiota of mice consuming no plant polysaccharides was characterized by a decreased relative abundance of Bacteroidetes. Although a direct effect of diet on C. parvum infected intestinal enterocytes cannot be ruled out, our results indicate that dietary fiber deprivation increases the susceptibility to severe cryptosporidiosis by modifying the metabolic activity of the intestinal bacteria. These observations underscore the potential of the bacterial metabolism to aleviate the impact of cryptosporidiosis, particularly in at-risk infants living in environments were enteric pathogens are prevalent.