Impact of Baizhu, Daqingye, and Hehuan extracts on the human gut microbiome

Authors: Scarino Lemons, Johanna; Narrowe, Adrienne; Liu, Linshu; Firrman, Jenni; Mahalak, Karley; VAN DEN ABBEELE, PIETER - Cryptobiotix; BAUDOT, AURELIEN - Cryptobiotix; DEYAERT, STEF - Cryptobiotix; LI, YANFANG - University Of Maryland; YU, LIANGLI - University Of Maryland

Submitted to: Frontiers in Cellular and Infection Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/23/2023
Publication Date: 12/7/2023
Citation: Scarino Lemons, J.M., Narrowe, A.B., Liu, L.S., Firrman, J., Mahalak, K.K., Van Den Abbeele, P., Baudot, A., Deyaert, S., Li, Y., Yu, L. 2023. Impact of Baizhu, Daqingye, and Hehuan extracts on the human gut microbiome. Frontiers in Cellular and Infection Microbiology. 13:1298392. https://doi.org/10.3389/fcimb.2023.1298392.
DOI: https://doi.org/10.3389/fcimb.2023.1298392

Interpretive Summary: There is a long history of using plants for their medicinal properties. In traditional Chinese medicine, three such herbs, Baizhu, Daqingye and Hehuan have been used for centuries. Some research has been done to try to figure out how these herbs work within the body, but very little has been done to explore their effect on the gut microbiome. Since the gut microbiome has been linked to human health in numerous ways we wanted to see whether any of the beneficial effects of these herbs could be attributed to changes they induced in gut bacteria after consumption. We did this by incubating human gut bacteria from fecal samples with these herbs in the lab. Baizhu and Daqingye did cause some small changes to the composition and function of the gut community which might help explain Baizhu's efficacy against gastrointestinal illness. Hehuan induced many more changes which could link its mental health promoting qualities to the changes it causes to the gut microbiome. Hehuan also increased the amount of opportunistic pathogens, which suggests that its use may not be right for everyone.

Technical Abstract: There is a long history of utilizing plants for their medicinal properties. In traditional Chinese medicine, the rhizome of Atractylodes macrocephala (Baizhu), the leaves of Isatis indigotica (Daqingye), and the bark of Albizia julibrissin (Hehuan) are prized for their palliative effects. While these plants have been used for centuries to treat gastrointestinal illnesses, epidemics, and mental health issues, modern researchers are still exploring the biological and chemical mechanisms responsible for their efficacy. Much of the research so far has described the impact of purified chemicals or mixed extracts from these plants on cells in tissue culture or rodent models, but few have explored the effect on the human gut microbiome. The gut microbiome has been linked to host health status both within the gastrointestinal tract and in distant tissues such as the heart, brain, liver, and kidneys. In our study, we assessed the individual effects of lipid-free ethanol extracts of Baizhu, Daqingye, and Hehuan on the human gut microbiome via short-term incubation using Systemic Intestinal Fermentation Research (SIFR®) technology, which enables ex vivo fermentation of extracts by donor fecal samples (n=6). While all orally consumed medicinal plants are processed through the human digestive tract their unique chemical profiles elicit differential effects on the gut microbiome. The changes to community structure and function observed in response to incubation with Baizhu and Daqingye were similar but greater in magnitude for Baizhu. These included decreases in the Bacteroidetes phylum and increases in Bifidobacterium spp. and short chain fatty acids which may contribute to Baizhu’s efficacy against gastrointestinal ailments. By comparison, the changes observed in the microbial communities treated with Hehuan were larger and included increases in multiple bacterial species known to produce secondary metabolites beneficial to mental health. In addition, many of the changes induced by Hehuan correlated with a rise in Enterobacteriaceae spp., which may make the herb contraindicated for some individuals.