"Nature" Chinese scientists isolated a bacterium that can decompose nicotine in the intestines of mice

A team of researchers from various institutions in China teamed up with a colleague in the United States to isolate a bacterium
that breaks down nicotine in the intestines of mice.
In their paper, published in the journal Nature, the team describes how they isolated the bacteria and why their findings could reduce the incidence of
fatty liver disease in humans.

Previous research has shown that smoking is the leading cause of
preventable death worldwide.
In addition to being associated with lung disease, smoking has also been linked
to fatty liver disease.
In the new study, the researchers found that a specific bacterium can break down nicotine in the gut of mice (due to forced smoking), reducing the likelihood of
fatty liver disease.

Studies have found that when humans (or mice) smoke, some nicotine enters the gut, leading to an increased risk of fatty liver disease and is associated with scarring and, in some cases, liver cancer
.

In the new study, researchers measured the amount
of nicotine entering the gut by comparing stool samples from 30 smokers and 30 non-smokers.
They then did the same experiment on mice and found similar
results.

Next, they sterilized the intestines of several lab mice and conducted nicotine experiments
again.
They found that mice with sterilized intestines had higher levels of nicotine, suggesting that at least one gut bacterium was breaking down nicotine
.
Then, through the elimination process, they were able to trace down the bacteria responsible for breaking down Bacteroides xylanisolvens, which produces an enzyme
that breaks down nicotine.

Previous studies have shown that xylan ethyl esters are also present in
the human gut.
The researchers next plan to study it and the enzyme it produces to see if the enzyme can be produced commercially and given to smokers to reduce their chances of developing fatty liver disease and thus liver cancer
.