Characterization of the Fecal Bacterial Microbiota of Healthy and Diarrheic Dairy Calves

Gomez, D.E.; Arroyo, L.G.; Costa, M.C.; Viel, L.; Weese, J.S.

dies have identified a mechanistic interrelation among Proteobacteria, the gut immune response, and inflammation. 48, 49 Dysregulated innate immune responses can elicit the bloom of Proteobacteria that promotes gut inflammation and facilitate inflammation or invasion by pathogens. 50, 51 Additionally, the relative abundance of Faecalibacterium spp. was lower in healthy calves, a somewhat surprising result because F. prausnitzii has been associated with anti-inflammatory properties by stimulating the production of anti-inflammatory cytokines, decreasing the secretion of the pro-inflammatory cytokines and by the production of butyrate. 52, 53 Contradictory results regarding the relative abundance of Faecalibacterium spp in feces of preweaned calves from different farms also have been reported in dairy 12, 27 and beef calves. 47 The reasons accounting for these differences are unclear, but differences in methodologies among studies as well as a farm-associated effects (management practices) could explain the differences in gut microbiota.