Safety evaluation of Butyricicoccus faecihominis DSM 34943

A novel strain of Butyricicoccus faecihominis DSM 34943 was isolated from the feces of a healthy human donor. In order to fully assess the safety of this strain, a full genomic assessment, further in-vitro characterization and a combined in-vivo subchronic 28-day and 90-day toxicity study is reported herein. B. faecihominis DSM 34943 was susceptible to antibiotics of human clinical relevance, was sensitive to bile and gastric juice pH conditions, and does not exhibit any aspects of virulence. This strain also demonstrates the ability to engraft the gastrointestinal tract of rats, persisting with continuous administration of the strain until the end of the study. Exposure to 2000 mg/kg BW/day B. faecihominis DSM 34943 did not produce any evidence of toxicity after either 28- or 90-days of exposure and did not translocate across the gastrointestinal barrier. Therefore, the NOEL for B. faecihominis DSM 34943, administered for 28- or 90-days, was determined to be the limit dose at 2000 mg/kg/day in male and female rats, a level which meets or exceeds calculated dose equivalent of 1.97 × 10¹¹ CFU/kg/day. B. faecihominis DSM 34943 activity was also evaluated in a DIO mice model and supplementation of B. faecihominis DSM 34943 resulted in significant improvement in insulin sensitivity, leptin, resistin and cholesterol levels, suggesting that this strain has potential as a safe next generation probiotic for metabolic health.