Super Astragalus polysaccharide in specific gut microbiota metabolism alleviates chronic unpredictable mild
Qing Liu1, Peng Ding2, Ying Zhu3
1Department of Naval Nutrition and Food Hygiene, Faculty of Naval Medicine, Naval Medical University, Shanghai 200433, China.
Abstract:
Chronic stress affects intestinal microbiota. Astragaloside IV (AS), called super Astragalus polysaccharide, is a monomer component of traditional herbs Astragalus membranaceus which belongs to medicinal food homology (MFH), exerts a neuroprotection effect, but the underlying mechanism has not yet been elucidated. Intestinal flora is also involved in the biotransformation of the active ingredients of MFH species, thus affecting their physiological and pharmacological properties. In this study, we found that AS improved CUMS-induced cognitive impairment, inhibited neuroinflammation, and restored intestinal barrier damage, but the improvement was suppressed by the elimination of gut microbiota, suggesting a key regulatory role for the microbiota. The results of 16S rDNA sequencing showed that AS treatment significantly increased the relative abundance of Lactobacillus reuteri (L. reuteri) and Bacteroides acidifaciens. Furthermore, supplementation of L. reuteri rather than Lactobacillus plantarum restored the effect of AS-supplied dysbiosis mice via inhibition of inflammatory repose and the maintenance of the intestinal epithelial barrier, indicating that dietary AS requires L. reuteri to ameliorate cognitive injury. These findings provide evidence for new therapeutic strategies to treat chronic stress and support the role of specific bacteria in the intestinal environment that metabolizes the AS.
Insights
Astragaloside IV (AS) alleviates chronic stress-induced cognitive impairment by modulating gut microbiota. Specifically, AS enhances Lactobacillus reuteri, which is crucial for its neuroprotective and anti-inflammatory effects.
Area of Science:
- Neuroscience
- Microbiology
- Pharmacology
Background:
- Chronic stress negatively impacts cognitive function and intestinal microbiota composition.
- Astragaloside IV (AS), a compound from Astragalus membranaceus, shows neuroprotective potential, but its mechanism involving gut microbiota is unclear.
- Medicinal food homology (MFH) species' active ingredients are metabolized by gut flora, influencing their efficacy.
Purpose of the Study:
- To investigate the role of gut microbiota in mediating the cognitive benefits of Astragaloside IV (AS) under chronic stress.
- To identify specific gut bacteria influenced by AS and responsible for its therapeutic effects.
Main Methods:
- Chronic unpredictable mild stress (CUMS) model in mice.
- Treatment with Astragaloside IV (AS) and gut microbiota elimination.
- 16S rDNA sequencing for gut microbiota analysis.
- Supplementation with specific bacterial strains (Lactobacillus reuteri, Lactobacillus plantarum).
Main Results:
- AS treatment improved CUMS-induced cognitive impairment, reduced neuroinflammation, and repaired intestinal barrier damage.
- The beneficial effects of AS were abolished upon gut microbiota elimination.
- AS significantly increased the abundance of Lactobacillus reuteri and Bacteroides acidifaciens.
- Lactobacillus reuteri supplementation, but not Lactobacillus plantarum, restored AS's therapeutic effects in dysbiotic mice.
Conclusions:
- Gut microbiota plays a critical role in mediating the cognitive-enhancing and anti-inflammatory effects of Astragaloside IV (AS).
- Lactobacillus reuteri is a key bacterial species required for AS to ameliorate chronic stress-induced cognitive injury.
- These findings highlight a novel therapeutic strategy for stress-related cognitive disorders involving AS and specific gut bacteria.
