Probiotics may help to prevent and treat colon cancer
A new study looks at the potential of probiotics in the prevention and treatment of colorectal cancer associated with inflammatory bowel disease. So far, the results following tests in mice are promising, but further investigation is required.
According to the
Existing studies suggest that some of the leading factors for increased risk of colorectal cancer include having been diagnosed with inflammatory bowel disease, genetic factors, smoking, lack of physical activity, and a high body mass index (BMI).
According to recent investigations, the gut microbiome plays a key role in the development of colorectal cancer. However, many of the mechanisms at play still remain unclear. Some research suggests that using probiotics to influence the microbiome may help to prevent tumor formation.
A new study led by Dr.
The researchers findings are published in
Probiotic minimizes tumor formation
In adult mice, it has been noted that the lack of an enzyme called histidine decarboxylase (HDC) made the animals significantly more susceptible to developing colorectal cancer associated with inflammation of the bowels.
HDC is produced by L. reuteri and helps to convert L-histidine, which is an amino acid with a role in protein synthesis, to histamine, which is an organic compound involved in the regulation of the immune response.
They used HDC-deficient mice, to which they administered L. reuteri. They also administered a placebo compound to mice in the control group, in order to compare the effects.
L. reuteri was given to the mice once before, and once again after, the induction of tumor formation through the administration of azoxymethane, a carcinogenic chemical, and DSS, a substance that stimulates inflammation.
Fifteen weeks after this procedure, the mices gastrointestinal tracts were studied, to control for tumor progression and the effect of the probiotic.
The researchers found that L. reuteri stimulated the production of HDC and raised the levels of histamine in the colon.
Positron emission tomography was used to scan for tumors, and the researchers noted that the mice that had ingested the probiotic exhibited fewer tumors and of smaller sizes. Conversely, the animals from the control group had more, and larger, tumors.
Inactive strains of L. reuteri, which were HDC-deficient, did not exhibit any protective effects.
The researchers also noted that the probiotic (its active strain) was effective in reducing the inflammation stimulated by the chemicals that is, DSS and azoxymethane that had been administered to the mice.
Harnessing microbiome for treatment
Our results suggest a significant role for histamine in the suppression of chronic intestinal inflammation and colorectal tumorigenesis [tumor formation], says
Scientists are still unsure what the function of histamine is in relation to cancer in humans. Yet data collected from 2,113 people diagnosed with colorectal cancer, sourced from 15 separate datasets, suggested that individuals who have higher levels of HDC fare better and have a higher survival rate.
Taking this into consideration, the team hopes that probiotics that help to convert L-histidine into histamine could eventually be used to aid colorectal cancer treatment.