Safety Assessment of Aspergillus cristatus CCNH008 for Potential Use in Food and Health Applications

Aspergillus cristatus is a key microorganism involved in the fermentation of Fu brick tea, but systematic strain-level safety data remain limited despite its long history of use in dark tea production. In this study, the toxicological safety of A. cristatus CCNH008 was assessed through acute oral toxicity assay, a 90-day repeated oral toxicity study with a recovery period and genotoxicity assays. In acute oral toxicity tests, CCNH008 caused no mortality, no adverse clinical signs, and no treatment-related effects on bodyweight or pathology in mice or rats, with an LD50 greater than 10 g/kg bodyweight. In the 90-day repeated oral toxicity study in rats, the oral administration of CCNH008 at doses up to 1.67 g/kg bodyweight/day produced no treatment-related changes in clinical signs, bodyweight, food consumption, hematological or biochemical parameters, urinalysis, organ weights, or histopathology, including during a 28-day recovery period. Genotoxicity was evaluated using a bacterial reverse mutation assay, an in vitro mammalian chromosome aberration test, and an in vivo mammalian erythrocyte micronucleus test; no mutagenic or clastogenic effects were observed. Collectively, these findings demonstrate that CCNH008 shows no evidence of acute, subchronic oral toxicity, or genotoxicity, providing important strain-level safety evidence to support its potential application in food-related products.