Yogurt is a kind of food that we all like very much. They can be seen everywhere in supermarkets and convenience stores.
The most well-known benefit of yogurt is that it is rich in probiotics, which can promote our digestion and absorption.
In a report, Medical News says that recently, CELL sub-journal published a research paper pointing out that probiotics in the gut may promote the occurrence of tumors!
Seeing this, everyone was startled, and silently put down the yogurt in their hands.
Gut microbes may be involved in tumorigenesis!
We found that microbial tryptophan metabolites can inhibit antitumor immunity by activating the aryl hydrocarbon receptor (AhR) of tumor-associated macrophages (TAMs).
AhR is a receptor for tryptophan metabolites, which can effectively inhibit the inflammatory response, and AhR is highly expressed in TAM.
We know that macrophages, as a part of innate immunity, play an irreplaceable role in the activation of the body’s specific immunity.
Their polarization towards pro-inflammatory can effectively promote effector cells such as CD8+ T cells in vivo to exert cytocidal effects, thereby resisting tumor.
However, in the tumor microenvironment (TME), macrophages are often polarized in an anti-inflammatory direction, suppressing immune responses and promoting tumor growth by producing anti-inflammatory cytokines such as IL-10.
Gut microbes colonize our guts to help the body perform many important physiological activities. Much of the food we eat depends on them for catabolism.
Foods rich in tryptophan produce indole after microbial metabolism, which binds to AhR as a ligand and activates downstream reactions.
This study focused on pancreatic ductal carcinoma (PDAC), a disease with a poor prognosis.
Therefore, exploring whether the expression of AhR promotes the phenotypic transformation of TAMs and thus promotes the progression of PDAC is of great significance for the treatment of PDAC.
We know that yogurt contains many probiotics, including lactic acid bacteria.
However, this article is based on the analysis of the intestinal flora of mice.
In mice, lactic acid bacteria are the main microorganisms that produce indole, and they are not necessarily applicable to humans!