Enhancement of Active Substances in Astragali Radix Broth with Lactic Acid Bacteria Fermentation and the Promotion Role of Chlorella Growth Factor

Astragali Radix, a traditional Chinese herbal medicine widely used for its medicinal properties, is known to be rich in active components that possess various pharmacological effects. However, the effectiveness of microbial fermentation in enhancing the content of these active substances remains unclear. In this study, a microflora of lactic acid bacteria was used to ferment Astragali Radix, and the promoting effect of Chlorella Growth Factor (CGF) on the fermentation process was investigated so as to clarify the changes in major active compound content in the fermented Astragali Radix broth. Non-targeted metabolomic analysis based on ultra-high-performance liquid chromatography–mass spectrometry was conducted to analyze the differences in metabolites before and after fermentation. The results showed that the total polysaccharide, total flavonoid, and total saponin content in the fermented Astragali Radix broth increased by up to 51.42%, 97.76%, and 72.81% under the optimized conditions, respectively. Streptococcus lutetiensis was the dominant bacterial species during the fermentation process. There were significant differences in metabolites in the fermentation broth before and after fermentation, among which amino acids (such as L-Aspartyl-L-Phenylalanine, etc.) and saponin compounds (such as Cloversaponin I, Goyasaponin I, etc.) were the main upregulated metabolites, which can enhance the physiological functions of Astragali Radix fermentation broth. The CGF exhibited the ability to promote the increase of active substance content in the fermented Astragali Radix broth.