Gut Bacterial Response Pattern And Mechanism Study To Five Dietary Herbal Supplements In Mice

Herbs are widely used in alternative therapy,but their therapeutic mechanisms are still not fully revealed.A growing number of studies suggest that gut microbiota play a crucial role in therapy with herbal medicines through complicated interplay with the components of these natural products.However,the gut bacterial response patterns under treatment with herbal medicines remain unexplored,especially the underlying ecological mechanisms.This has limited the clinical application of herbal medicines.Here,five herbal medicines were selected to add into the diet of mice,16 S r RNA sequencing method was used to investigate their effects upon the gut bacterial community and identify the drivers which shape gut bacterial diversity and mediate species coexistence patterns in mice,including Angelica Sinensis radix,Eucommiae Cortex,Astragali Radix,Cistanches Herba and Gastrodiae Rhizoma.Clarifying the response patterns of gut bacteria to herbal medicines and their drivers will improve our understanding of the interaction mechanisms between them.The main results are as follow:1.Community assembly processes and species pool co-shape the β-diversity patterns of gut microbiotaAfter the addition of Chinese herbs or herbal aqueous extracts to the diet of mice,there was significant clustering in the composition of intestinal microorganisms in different groups,and the β-diversity of intestinal flora was significantly different.The β-diversity of intestinal flora was higher in the Angelica sinensis radix group and Cistanches herba group.The differences in intestinal flora composition among different groups were dominated by abundance differences,rather than species replacement.Angelica Sinensis radix and Cistanches Herba shaped the β-diversity patterns of gut microbiota by the community assembly processes and species pool.2.Community assembly processes affect the variations of phylogenetic nichesMost of the community assembly processes of intestinal flora in all groups were dominated by deterministic processes,but the Cistanches herba group was dominated by stochastic processes.The main ecological process of intestinal flora community construction in the normal diet group,Eucommiae cortex group,Astragali radix group and Gastrodiae rhizome group was homogeneous selection,while the main ecological process of community construction in the Angelica sinensis radix group was heterogeneous selection,and the main ecological process of community construction in the Cistanches herba group was diffusion limitation.Angelica sinensis radix and Cistanches herba change the community assembly processes and the phylogenetic distance,led to the changes of phylogenetic ecological niches.3.The linkage between phylogenetic niches,microbial network complexity and stabilityAll of the detected microbial networks were scale-free,modular,and displayed small world attributes.The bacterial co-occurrence patterns of the normal group were more similar to the Astragali radix group,Eucommiae Cortex group,and Gastrodiae rhizome group,while the Angelica sinensis radix group was similar to the Cistanches herba group.The response patterns of intestinal flora in each group showed significant phylogenetic conservation.In the Angelica sinensis radix group and Cistanches herba group,the phylogenetic distances among taxa in the phylogenetic tree were significantly increased and phylogenetic heterogeneity were enhanced within groups.On the one hand,increased phylogenetic distance promote cohesion.Positive cohesion increased significantly in gut microbial communities in the Angelica sinensis radix group and Cistanches herba group,which also decreased the ratio of negative:positive cohesion.Negative cohesion decreased significantly in gut microbial communities in the Astragali radix group and Cistanches herba group.On the other hand,increased phylogenetic distance reduce the robustness of networks.The robustness of networks were decreased in the Astragali radix group and Cistanches herba group.Variations of phylogenetic niches mediate the bacterial response patterns and influence the robustness of bacterial cooccurrence network.In conclusion,the results demonstrated that the supplement of the herbal medicines observably altered not only the microbial diversity,but also the complexity and stability of network.Furthermore,bacterial responses to the herbal supplements were significantly phylogenetically conserved.Variations of phylogenetic niches,affected by community assembly mechanisms,mediated response patterns of gut bacteria to dietary herbal medicines supplements.This study clearly illustrates the variations of gut bacterial response and coexistence patterns under treatments with herbal medicines and the ecological mechanisms behind them.These findings improve our ability to predict how gut bacteria respond to dietary herbal supplements and help to account for the potential therapy mechanism of herbs.