Gut bacteria can cause a variety of diseases

don't look down on bacteria, tiny creatures that are hard to see with the naked eye can be neither angels nor demons. Some of them are good for your health, and some can be destructive.
, there is growing evidence that some gut cancers are caused by bacteria, New Scientist reported. The microbe appears to trigger a different type of mutation in human DNA, which is up to 1 in 10 in colon cancer patients.
is the first time we've found bacteria that alter DNA and cause cancer, " he said. Hans Clevers of the Hubrecht Institute in the Netherlands said.
is often thought to be caused by random genetic mutations, and smoking and unhealthy eating habits increase the risk of colon cancer in humans. But more recently, researchers have suggested that certain gut bacteria may be "suspects" of mutations, including E. coli, which produces substances that destroy human DNA.
The strain, known as pks-E. coli, is more common in the faeces of colon cancer patients, but it is not clear whether it is the cause of the tumor or whether the human environment for cancer is better suited to its growth.
to solve these problems, Clevers and the team recently injected pks plus E. coli into cells in the human gut (organs cultured in-body). They found that the microbe triggered different patterns of DNA damage: in the four "letters" (A, T, C, G) encoded in the DNA, mutations occurred on a specific combination of two letters.
team then reviewed two previous studies in which nearly 6,000 tumor genes, mainly from the colon, were sequenced. Between 5 and 10 percent of colon cancer patients have the same mutation pattern, but not in other types of tumor patients. "We believe this finding is strong evidence that these bacteria are indeed the cause of colon cancer." Clevers said.
think it's a decisive factor, but it's definitely a huge step forward," said Cynthia Sears of Johns Hopkins University in the U.S.
Clevers said that if the findings were confirmed, people could use antibiotics to remove carcinogenic bacteria and then use probiotic capsules containing safe and beneficial E. coli strains to prevent the resurgence of dangerous strains.
study, researchers found a lack of certain bacteria or a different disease, ulcerative colitis. Once the disease occurs, the body's immune system appears to attack the intestines, causing inflammation.
Aida Habtezion of Stanford University and colleagues found that people with the disease had lower diversity of gut tracts and a lack of special bio-chemicals such as secondary bile acid in their faeces. These compounds are secreted by a bacteria lacking in patients with ulcerative colitis.
Habtezion team injected bile acid into mice with similar ulcerative colitis and found a reduced inflammation of the intestines.
team has begun clinical trials in 15 patients with ulcerative colitis to see if bile acid can also alleviate symptoms in humans. The results of the trial will be announced next year.
bile acid had previously been used as an oral drug to treat liver disease, so the study could move quickly into human trials. However, in order for bile acid to work best, Habetzion believes it should be used as an enema to enter the colon in an enema manner.
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