Molecules produced by gut bacteria can help the human body fight cancer
Our guts are wonderful places, filled with a myriad of microbes. These little life forms help us with everything from Fermentation of fibers to feel full. But its effects don’t just stay in the gut.
We know that gut microbes such as bacteria and yeast have a role to play diabeticAnd the depression And the Neurovascular disease. Now, scientists have discovered that molecules produced by stomach bacteria can help the human body when it comes to the immune system, even if they go so far as to help fight tumors.
“The results are an example of how gut bacteria metabolites can alter metabolism and gene regulation in our cells and thus positively impact the efficiency of tumor therapies,” Immunologist Mike Low says From the University Hospital Würzburg in Germany.
short chain fatty acids (SCFAs) are one of the beneficial molecules that are produced when dietary fiber is fermented in the intestine. The main SCFAs are acetate And the butyrate, besides the less common pentanoateIt is only found in some bacteria. All of these SCFA fatty acids have a range of positive health effects on humans, such as regulating insulin resistance, cholesterol, and even appetite.
Luu and colleagues now find that butyrate and pentanoate also enhance the antitumor activity of a type of killer T cell known as CD8, by reprogramming the way it works. For the first time, they demonstrated this experimentally in mice.
“When short-chain fatty acids reprogram CD8 T cells, one result is increased production of pro-inflammatory and cytotoxic molecules,” said Dr. Lu . says.
“We were able to show that short-chain butyrate fatty acids, and in particular, pentanoate, are able to increase the cytotoxic activity of CD8 T cells.”
Using lab mice, the team found this to be certain coexistence Bacteria produce pentanoate. For example, human gut bacteria are relatively rare, Megasphaera Marseille Strengthening small proteins called cytokines In killer T cells, which leads to an increased ability to destroy cancer cells.
As a control, the team performed experiments with other non-pentanoate-producing bacteria and found no effect on cytokine levels. This finding may be particularly useful for therapies that take advantage of the immune system to fight cancer.
Some cancer cells have proteins on their surfaces that can bind to proteins on T cells, causing inflammation. The immune ‘checkpoint’ response Which tells the killer cell to keep its target – in this case, the cancer cell. Treatment with immune checkpoint inhibitors (ICIs) works by blocking these checkpoint proteins, allowing T cells to do their job and destroy cancer cells.
“A specific joint consortium of 11 human bacterial strains produced robust anti-tumor CD8+ T-cell-mediated immunity,” The team wrote in their new paper.
“This study demonstrated that a mixture of low-abundance human symbionts was able to significantly enhance the efficacy of ICI treatment in mice.”
This exciting discovery brings us closer to understanding how the right mix of gut bacteria can help advance ICSI treatments for cancer patients.
The team also looked at a genetically modified type of T cell called CAR-T . cells which are used in immunotherapy, and found that bacterial adjuvant works in the same way, especially with solid tumors.
Although the researchers caution that there is a long way to go before we can apply these findings in the clinic, this important finding is another reason to love your gut bacteria and remember to eat more fiber.
The search was published in Nature Connections.
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