Influence of the artificial sodium saccharin sweetener Sucram(R) on the microbial community composition in the rumen content and attached to the rumen epithelium in dairy cattle: A pilot study

The products of rumen microbial fermentations are considered essential for animal growth and performance. Changes in these microbial communities can have major effects on animal growth and performance. Saccharin-based artificial sweeteners can be included in livestock diets to increase palatability and encourage feed intake. Despite the importance of the rumen microbial fermentation, little or no research is available regarding how saccharin-based artificial sweeteners affect rumen content and rumen epithelial microbial communities. The aim of this study was to identify changes in both the rumen content and rumen epithelial microbial communities in response to the supplementation of Sucram(R), a sodium-saccharin-based sweetener (Pancosma S.A./ADM Groups, Rolle, Switzerland) during standard, non-stress conditions using 16SrRNA gene amplicon sequencing. The rumen epithelial and rumen content microbiota of five Holstein-Friesian milking dairy cattle were compared before (baseline, BL) and after a 28-day supplementation of Sucram(R). Illumina MiSeq-based 16S rRNA gene sequencing was conducted, and community analysis revealed significant changes in the abundance of specific phylotypes when comparing BL to Sucram(R) experimental groups. Sucram(R) did not have a significant effect on overall rumen microbial community structure between experimental groups. Statistically significant changes in microbial community composition following Sucram(R) supplementation were observed most consistently across a number of bacterial taxa in the rumen epithelium, while fewer changes were seen in the rumen content. Predicted genomic potentials of several significantly different OTUs were mined for genes related to feed efficiency and saccharin degradation. Operational taxonomic units (OTUs) classified as Prevotella and Sharpea were significantly (p<0.05) increased in samples supplemented with Sucram(R), whereas a reduction in abundance was seen for OTUs classified as Treponema, Leptospiraceae, Ruminococcus and methanogenic archaea. This is the first study to report an effect of Sucram(R) on ruminant microbial communities, suggesting possible beneficial impacts of Sucram(R) on animal health and performance that may extend beyond increasing feed palatability.