Functional constipation (FC) is one of the most common gastrointestinal conditions globally, affecting an estimated 14% of the population. While Western medications are widely used, they are often associated with long treatment cycles, high recurrence, and unwanted side effects.
In traditional Chinese medicine (TCM), Atractylodes macrocephala—commonly known as Bai Zhu—is a core herb for improving digestion and bowel function. Clinically, both raw and stir-fried forms (Sheng Bai Zhu and Chao Bai Zhu) are used, but which is more effective? A new animal study finally offers some clarity.
The study used 72 rats induced with FC via diphenoxylate compound. The rats were divided into eight groups, including control, model, positive control (mosapride), and six Bai Zhu groups—raw vs. processed, at high, medium, and low doses (9 / 3 / 1 g/kg).
Outcome measures included time to first black stool, fecal water content, small intestinal transit rate, colon histology, levels of neurotransmitters (5-HT, SP, VIP), and gut microbiota profiling via 16S rRNA sequencing.
Stir-frying Bai Zhu increased the levels of atractylenolide I and II, while decreasing atractylenolide III and atractylone. These shifts suggest that processing alters the herb’s pharmacological properties by modifying its active compound profile.
✔ Bowel Movement: Rats receiving raw Bai Zhu showed significantly shorter time to first black stool—up to 28.6% faster in the high-dose group compared to processed Bai Zhu. Fecal moisture was also higher.
✔ Intestinal Motility: Small intestine transit rates were significantly improved in the raw Bai Zhu group (P<0.01).
✔ Neurotransmitter Regulation: Raw Bai Zhu raised levels of 5-HT, SP, and VIP by 15–20% more than its processed counterpart.
Both raw and processed Bai Zhu reduced the relative abundance of Firmicutes and increased Bacteroidota—an important rebalancing for gut health. However, raw Bai Zhu had a more pronounced effect, helping microbial communities shift closer to those in the healthy control group. 153 OTUs unique to the model group were substantially normalized.
Colon tissue stained via HE showed that both raw and processed Bai Zhu improved mucosal integrity and restored goblet cell counts. Notably, the raw Bai Zhu group exhibited thicker mucosal layers and better structural repair.
Raw Bai Zhu appears to act through multiple synergistic mechanisms:
Stir-frying is believed to reduce the dispersing and moving qualities of Bai Zhu, aligning with traditional TCM theory that raw forms are better for promoting bowel movement, while processed forms may be more suitable for diarrhea or mixed bowel patterns.
This study provides modern scientific support for the classical principle: “Sheng for purging, Chao for tonifying.”
Importantly, Bai Zhu demonstrates a unique multi-target approach—modulating neurotransmitters, repairing tissue, and rebalancing gut flora—offering a safer, more holistic alternative to harsh laxatives.
At Herbal Planet™, we believe in the synergy of ancient knowledge and modern science. This study beautifully illustrates how traditional preparation methods matter—not just philosophically, but functionally and biologically. As always, transparency, natural healing, and integrity guide everything we do.
