## 4 Discussion
### Metabolic Pathways of Top Scoring Enzymes
The same study demonstrates the role of various bacteria in CRC development and indicates that _Citrobacter radentium_ may contribute to tumor development by inducing epithelial-mesenchymal transition in the intestinal cells. The research highlights the importance of microbial metabolites and signaling pathways in CRC progression [112]. These findings suggest that _Citrobacter_ species may play a role in colorectal cancer development through mechanisms such as inducing epithelial-mesenchymal transition and activating oncogenic signaling pathways. In addition to other _Salmonella_ strains, bacteria associated with colorectal cancer such as _Klebsiella pneumoniae_ have also been found. _Klebsiella pneumoniae_ is an opportunistic pathogen known to cause infections, particularly in immunocompromised individuals [113]. Chronic infections and inflammation are major risk factors for cancer, including CRC [114]. _Klebsiella pneumoniae_ has been implicated in chronic intestinal inflammation, which is thought to promote an environment conducive to cancer development [115]. Long-term inflammation can lead to DNA damage, immune system dysfunction, and the activation of oncogenic pathways [100]. The bacterium may promote tumorigenesis by altering gut microbiota composition and fostering a pro-inflammatory environment [97]. Certain strains of _Klebsiella pneumoniae_ produce carcinogenic metabolites, which can directly damage the host DNA, potentially leading to mutations and cancer development. Some studies have shown that _Klebsiella_ can induce DNA damage in host cells, possibly through the production of toxic metabolites or the secretion of virulence factors that interfere with host cell signaling [116]. _Klebsiella pneumoniae_ produces several virulence factors, such as lipopolysaccharidesaccharides (LPS), siderophores, and capsular polysaccharides, which may play a role in CRC development. These virulence factors can trigger immune responses, cause inflammation, and interact with the host's cells in different ways that could support cancer development. The ability of _Klebsiella_ to form biofilms is another important factor. Biofilms protect the bacteria from immune responses and antibiotics, potentially allowing the bacteria to persist in the gut and may contribute to chronic inflammation. _Klebsiella pneumoniae_ has been linked to increased tumorigenesis in animal models of CRC. It has been suggested that the bacterium may enhance the development of colonic tumors in genetically predisposed mice by promoting chronic inflammation and altering immune responses. There is evidence that _Klebsiella_ can interact with the host cell pathways that regulate inflammation, immune responses, and tumor growth, thus potentially playing a role in promoting CRC. Another study revealed that _Eskherichia_ and _Klebsiella_ were found to be enriched in the intestines of CRC patients [67]. The authors also showed that _Klebsiella_-induced inflammation may contribute to tumor formation by influencing immune cell activity and cytokine release. Another study showed that _Klebsiella pneumoniae_ interacts with the host's immune system in several ways that could affect both local inflammation and systemic immune responses, contributing to cancer progression [117]. Immune responses play a critical role in both the prevention and progression of CRC, and changes in the microbial populations in the gut could contribute to an environment conducive to CRC development. Gut microbiomes can modulate the immune response in a way that might influence cancer progression. It is important to note that the human gut microbiome is complex, and research is ongoing in order to fully understand the relationships between various microorganisms, their enzymatic activities in different pathways, and cancer development.