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.

The relative abundance of Actinobacteria was significantly increased in healthy calves. At the genus level, LEfSe analysis identified enrichment of Bifidobacterium and an unclassified genus of the Bifidobacteriaceae family in healthy calves. Changes in the relative abundance of Bifidobacterium have been reported with different dysbiosis-associated intestinal diseases. 57, 58 Bifidobacteria have been reported to prevent gastrointestinal infections by outcompeting pathogenic viruses or bacteria for binding sites on epithelial cells. 59, 60 Bifidobacteria also produce short chain fatty acids that are transformed to butyrate and stimulate growth of butyrate-producing bacteria. 59 Butyrate has been shown to have trophic and immunomodulatory effects on the intestinal epithelium. 61, 62 Bifidobacterium also can contribute to the gut health by production of inhibitory substances, 62, 63 and modulating the gastrointestinal immune system response. 64, 65 These characteristics can explain the positive impact of Bifidobacterium-based probiotics on prevention of gastrointestinal diseases in calves. 66