We all know that the gut is home to a wide range of bacteria, which constitute a protective microbiome. However, not all bacteria found in the stomach and intestines are beneficial.
Fusobacterium is one of the bacterial species recently identified in the gastrointestinal tract, with implications for the treatment of colorectal cancer. Keep on reading and discover more interesting information on the connection between Fusobacterium and colorectal cancer.
What is Fusobacterium?
According to recent research, Fusobacterium is found at the site of colon and rectal tumors. The same studies have confirmed that these bacteria are also found in the metastases associated with colorectal cancer, in different parts of the body. Researchers have used antibiotics to kill bacteria, using mice models with colorectal cancer. Interestingly enough, the tumor growth slowed down and the prognostics of survival improved.
In the future, the treatment for colorectal cancer might focus on targeting potentially-harmful microbes. This could be extended to other types of cancer, as more information is revealed about the therapeutic potential of antibiotics.
The research also confirmed that a tumor contains not only cancerous cells but also non-cancerous cells and microbes. If the therapy were to be effective, it would have to target all the constituents of the tumor (including microbes such as Fusobacterium).
Can the Reduction of Bacteria Suppress the Tumor Growth?
It was only recently discovered that bacterial species such as Fusobacterium are found in the colorectal tumors. In order to confirm the presence of bacteria at different tumoral sites, researchers resorted to whole-genome sequencing.
Their research was performed on frozen tissue samples, including both primary tumors and metastases (liver). The research confirmed the presence of Fusobacterium in both primary tumors and liver metastases.
Initially, it was believed that new bacterial cells travel to the site of the metastases, joining the already-present cancerous cells. However, the recent research confirmed that the Fusobacterium bacteria travel at the same time with the cancerous cells, through the bloodstream.
The researchers wanted to determine whether the antibiotic treatment might have an impact on the tumor growth. They initially administered erythromycin to the mice affected by the colorectal cancer, without obtaining any positive results.
Nevertheless, when they administered metronidazole, the number of bacterial species in the tumoral tissue reduced. It was also discovered that the antibiotic treatment reduced the rate at which the tumoral cells proliferated, preventing the tumor from growing.
Could This be the Future of the Colorectal Cancer Treatment?
Further research is necessary to determine the underlying connection between Fusobacterium as bacterial species and colorectal cancer cells. At the moment, it is known that Fusobacterium might actually provide the tumor with essential nutrients to grow. Researchers believe that the tumor benefits from the presence of these bacteria, receiving growth signals from them as well.
At the same time, the tumor provides the bacteria with an environment in which it can grow and thrive. It offers immune protection, allowing it to develop within the gastrointestinal tract (immune-protected colonization).
For all of these reasons, scientists believe that, in the future, the treatment for colorectal cancer might target the Fusobacterium bacterial species living in close connection with the tumor.
The potential antibiotics that might be used to eliminate the Fusobacterium in patients diagnosed with colorectal cancer would have to present a high level of particularity. Broad-spectrum antibiotics are not recommended, as they will target all bacteria in the GI tract, including the one that is beneficial for our health.
Thus, such a treatment might end up doing more harm than good. Not to mention, it could have a negative impact on the response to the cancer therapy (further research necessary to determine how).
The gut microbiome is a complex structure and one that helps us maintain the best possible state of health. As long as it maintains its normal balance, we will be protected against bacterial proliferation and its consequences. The treatment will have to destroy only the cancer-associated bacteria, without having an additional impact on the rest of the gut microbiome.
What makes Colorectal Cancer the Leading Cause of Death?
The above-mentioned research is even more important, given the fact that colorectal cancer is the 4th leading cause of death in the world. In performing this study, scientists were able to confirm that Fusobacterium is an invasive bacterial species, supporting the inflammation in the gastrointestinal tract.
According to the known medical information, chronic inflammation is one of the major risk factors associated with the appearance of malignant tumors (including colorectal cancer).
It was confirmed that Fusobacterium is abundantly present in the colorectal tumors but further research is required, in order to determine the role of these bacterial species might play in the tumor genesis. The bacteria might arrive and benefit from the presence of the tumor, as this is an immune-compromised site (where it can thrive and develop).
However, researchers are also interested in exploring its role in the etiology of the tumor and the associated pro-inflammatory mechanisms.
It is known that colorectal cancer often appears from previous existent changes in the GI tract, such as polyps. In the future, through the screening for Fusobacterium, scientists hope to identify colorectal cancer at an early stage and thus improve the chances for survival.
Future studies will concentrate on analyzing the connection between the Fusobacterium infection and tumor progression. New therapies, such as vaccination or targeted antimicrobial drugs might be used for such medical problems.
In conclusion, the presence of Fusobacterium bacteria can indicate a risk for tumor growth and spread in patients diagnosed with colorectal cancer. The screening of the future should include a microbial analysis of the colon and rectum, especially with regard to the presence of invasive microbes, such as Fusobacterium.
This opens the floor for further bacterial cancer therapy, with the research being extended to other forms of cancer. It is essential to identify other microbes that could increase the risk for different types of cancer, as well as the right antibiotic treatments to handle such health problems.
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