Genotoxicity, subchronic toxicity, and allergenicity evaluation of IgG Binding Protein CBB produced from Komagataellaphaffii.

Gut health is progressively understood to be the multifactorial outcome of genetics, diet, lifestyle, and immune function and the influence of the gut microbiota. Healthy microbial homeostasis can be disrupted by environmental factors such as diet and xenobiotics, which can lead to gut dysbiosis. Dysbiosis is frequently associated with the expansion of pathobionts such as Clostridioides difficile. IgG Binding Protein CBB facilitates the safe passage of TcdB; a toxin secreted by C. difficile, through the gastrointestinal tract helping to maintain gut homeostasis. To substantiate the safety of IgG Binding Protein CBB for its physiological benefit when consumed orally in food and beverages, toxicology assessments (a bacterial reverse mutation test, an in vitro micronucleus test, and a 13-week oral gavage toxicity study in rats) and an in silico allergenicity assessment were conducted. IgG Binding Protein CBB was determined to be non-genotoxic. No test article-related effects were reported in the 13-week study. Therefore, the highest dose administered (i.e., 614 mg/kg body weight/day) was determined to be the no-observed-adverse-effect level (NOAEL) for IgG Binding Protein CBB. The allergenicity assessment also demonstrated that IgG Binding Protein CBB had low potential for allergenicity and cross-reactivity.