## 3 Results
### Effect of GP on Gut Microbiota
#### 3.4.2 The Phylum, Family, and OTU Level of Gut Microbiota  
As shown in stacked histograms (Figure 9A), the Firmicutes, Actinobacteria, Bacteroidetes, Verrucomicrobia, Proteobacteria, Deferribacteres, and Tenericutes, were identified, in special, Firmicutes, Bacteroidetes, and Verrucomicrobia were the main phylum. The DSS stimulation was investigated to reduce the relative abundances of _Betaproteobacteriaa_, _Delaproteobacteriaa_, _Bacilli_, _Mollicutes_, _Erysipelotrichia_, _Deferribacteres_ and increased the abundances of _Verrucomicrobia_ and _Deferribacteres_. In the group of GP intervention, the relevant abundant of _Betaproteobacteriaa_, _Bacilli_, and _Mollicutes_ could be reversed compared with the DSS-induced group. However, the abundance of _Verrucomicrobiae_, _Erysipelotrichia_, and _Deltaproteobacteriaa_ showed no significant differences with PC. At the genus level, the _Akkermansia_, _Allobaculum_, _Bacteroides_, _Peptococcus_, _Bifidobacterium_, _Parasutterella_, _Saccharibacteria_, and _Clostridium_ were identified, among which, _Akkermansia_, _Allobaculum_, _Bacteroides_ were the main genus in all groups. The _Akkermansia_ is demonstrated to be a promising probiotic candidate for gut health and a decreasing abundance is revealed in IBD patients [29]. In the  
Figure 8: Effects of GP on microbial profiles based on OTU abundance. (**A**) Samples cluster tree; (**B**) PCA; (**C**) PLS.  
comparison between NC and PC group (Figure 9B), the _Akkermansia_ also had significant differences where the DSS (18.7) posed to have lower abundance than NC (26.8%). As expected, the two-dose GP intervention improved the _Akkermansia_ abundance and there were no differences between GP-1 (32.2%) and GP-2 (34.5%, \(p\) < 0.05). In addition, the DSS stimulation was investigated to decrease the relative abundances of _Parasutterella_ from NC (3.1%) to 0.20% (_p_ < 0.05), and the two-dose GP supplement had an improving effect with the abundance of 0.9% and 1.1%, respectively.  
Figure 9: Gut microbial community structures in mice. (**A**) Microbial community bar plot by phylum level; (**B**) comparative analysis of relative abundances of gut microbiota at the gene level. The different letters represent significant differences between different groups (_p_ < 0.05).  
Based on the taxonomic composition, the gut-microiota-induced metabolism function was compared in PC- and GP-treated groups. As shown in Figure S3, the stimulation of DSS caused a down-regulation of genes involved in protein export, peroxisome, lysine degradation, carbon fixation, folate biosynthesis, nitrogen metabolism, lipopolysaccharidescharide biosynthesis, biotin metabolism, as well as RNA degradation. The genes related to the bioactive process of ansamycins biosynthesis, glycerolipid metabolism, lysine biosynthesis, pentose phosphate pathway, and phosphotransferase system were all up-regulated in PC. Produced from pathogens and commensal bacterial, the toxins would be generated by the ansamycins and lipopolysaccharide biosynthesis, which inspired the clinical intestinal inflammation in the host tissues with the damage on the immune system [30].