Screening Probiotics for Anti-Helicobacter pylori and Investigating the Effect of Probiotics on Patients with Helicobacter pylori Infection.

Probiotics are natural microbial agents with beneficial properties such as bacteriostatic and anti-infective properties. Lactobacillus plantarum Q21, Q25 and QA85, were isolated from the Chinese specialty fermented food "Jiangshui" and proved to be highly resistant to Helicobacter pylori (p < 0.0001). In vitro results showed that Q21, Q25 and QA85 strongly inhibited H. pylori and could specifically co-aggregate H. pylori in vitro (more than 56%). Strains have the potential to adhere to cells and hinder H. pylori colonization (p < 0.0001). To assess the anti-H. pylori efficacy of strains in vivo, volunteers were recruited and a self-controlled study of probiotic intervention was conducted. Compared to pre-probiotics, volunteers who took Q21, Q25 and QA85 for 1 month showed significant improvement in discomfort, a significant reduction in GSRS scores (p < 0.05), and modulation of inflammatory response (p < 0.05). Q21, Q25 and QA85 resulted in a decreasing trend of H. pylori load in volunteers (454.30 ± 327.00 vs. 328.35 ± 237.19, p = 0.06). However, the strains were not significantly effective in modulating the imbalance of the gut microbiota caused by H. pylori infection. In addition, strains affect metabolic pathways by increasing the levels of O-Phosphoethanolamine and other related metabolites, which may ameliorate associated symptoms. Therefore, Lactobacillus plantarum Q21, Q25 and QA85 can be regarded as a candidate probiotic preparation that exerts direct or indirect anti-H. pylori effects by inhibiting H. pylori activity and colonization, reducing inflammation and discomfort, maintaining homeostasis in the internal environment, affecting the metabolic pathways and repairing the body barrier. They can play a role in relieving H. pylori infection.

Functional fractions of Astragalus polysaccharides as a potential prebiotic to alleviate ulcerative colitis.

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine that is significantly influenced by an imbalance in the gut microbiota. Astragalus membranaceus, particularly its polysaccharide components, has shown therapeutic potential for the treatment of UC, although the specific active constituents and their mechanistic pathways remain to be fully elucidated. In this study, we investigated two molecular weight fractions of Astragalus polysaccharides (APS), APS1 (Mw < 10 kDa) and APS2 (10 kDa < Mw < 50 kDa), isolated by ultrafiltration, focusing on their prebiotic effects, effects on UC, and the underlying mechanism. Our results showed that both APS1 and APS2 exhibit prebiotic properties, with APS1 significantly outperforming APS2 in ameliorating UC symptoms. APS1 significantly attenuated weight loss and UC manifestations, reduced colonic pathology, and improved intestinal mucosal barrier integrity. In addition, APS1 significantly reduced the levels of inflammatory cytokines in the serum and colonic tissue, and downregulated colonic chemokines. Furthermore, APS1 ameliorated dextran sulfate sodium salt (DSS)-induced intestinal dysbiosis by promoting the growth of beneficial microbes and inhibiting the proliferation of potential pathogens, leading to a significant increase in short-chain fatty acids. In conclusion, this study highlights the potential of APS1 as a novel prebiotic for the prevention and treatment of UC.

Fermented Astragalus and its metabolites regulate inflammatory status and gut microbiota to repair intestinal barrier damage in dextran sulfate sodium-induced ulcerative colitis.

Fermentation represents an efficient biotechnological approach to increase the nutritional and functional potential of traditional Chinese medicine. In this study, Lactobacillus plantarum was used to ferment traditional Chinese medicine Astragalus, the differential metabolites in the fermented Astragalus (FA) were identified by ultra-performance liquid chromatography-Q Exactive hybrid quadrupole-Orbitrap mass spectrometry (UPLC-Q-Exactive-MS), and the ameliorating effect of FA on dextran sulfate sodium (DSS)-induced colitis in mice were further explored. The results showed that 11 differential metabolites such as raffinose, progesterone and uridine were identified in FA, which may help improve the ability of FA to alleviate colitis. Prophylactic FA supplementation effectively improved DAI score, colon length and histopathological lesion in DSS-treated mice. The abnormal activation of the intestinal immune barrier in mice was controlled after FA supplementation, the contents of myeloperoxidase (MPO) and IgE were reduced and the contents of IgA were increased. The intestinal pro-inflammatory factors TNF-α, IL-1ß, IL-6, and IL-17 were down-regulated and the anti-inflammatory factors IL-10 and TGF-ß were up-regulated, suggesting that FA can intervene in inflammatory status by regulating the balance of Th1/Th2/Th17/Treg related cytokines. In addition, FA supplementation modified the structure of the intestinal microbiota and enriched the abundance of Akkermansia and Alistipes, which were positively associated with the production of short-chain fatty acids. These microbes and their metabolites induced by FA also be involved in maintaining the intestinal mucosal barrier integrity by affecting mucosal immunity. We observed that intestinal tight junction protein and mucous secreting protein ZO-1, occludin, and MUC2 genes expression were more pronounced in mice supplemented with FA compared to unfermented Astragalus, along with modulation of intestinal epithelial cells (IECs) apoptosis, verifying the intestinal mucosal barrier repaired by FA. This study is the first to suggest that FA as a potential modulator can more effectively regulate the inflammatory status and gut microbiota to repair the intestinal barrier damage caused by colitis.