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Bill Sullivan, Indiana University
(DEVELOPMENT) Imagine being a police officer. You notice a car in the front that spins all the way. Pull the driver and he is intoxicated. In a vague speech, she swears she didn't drink a drop of alcohol all day. Would you believe her?
In 2016, a woman who had a blood alcohol level four times the legal limit was acquitted of her DUI charge after she was found to have an extremely rare condition called "syndrome". auto brewing. " People with this syndrome carry germs in their intestines that produce unusually high levels of the alcohol they produce when they break down sugars and carbohydrates.
While auto-brewing syndrome is a prime example, one may wonder: Can gut microbes influence other healthy or behavioral traits? Jing Yuan of the Beijing Institute of Pediatrics has published a new study on cell metabolism, which shows that the gut microbiota can cause fatty liver disease by producing high levels of alcohol.
I am a microbiologist and am intrigued by the role of the gut microbes ̵
Sick liver without drinking
The accumulation of excess fat in the liver can cause serious health problems, including inflammation, which can lead to cirrhosis (scars) and cancer of the liver fraction. Most people associate fatty liver disease with alcoholism; nevertheless, non-alcoholic fatty liver disease, which affects a surprising 80 to 100 million Americans, occurs without excessive alcohol intake. There are many causes of NAFLD, such as obesity, insulin resistance, high cholesterol, or hepatitis C infection
. Now Yuan and her colleagues may have identified another.
The discovery came about when doctors identified a patient suffering from both auto-brewing syndrome and severe NAFLD. When the researchers examined the faeces samples from the patient, they discovered a type of bacterium called Klebsiella pneumoniae. This specific strain of K. pneumoniae produces between four and six times the amount of alcohol that strains of the same bacteria do in healthy people. This prompted Yuan and her team to examine a group of 43 other patients with NAFLD. They found that 61% of them had K. pneumoniae, which produces unusually large amounts of alcohol. Among the 48 healthy people, only 6% contained such bacteria.
The team notes that K. pneumoniae bacteria are only slightly more abundant in the gut of patients with NAFLD. The amount of alcohol produced by the germs varied. But can the excess alcohol produced by the bacteria actually lead to a fatty liver?
Some people have a microbrewery in their gut
To solve the cause-and-effect problem, scientists feed on high alcohol-producing K. pneumoniae bacteria in healthy mice. Within one month, these mice develop measurable symptoms of fatty liver that progresses to cirrhosis within two months. Bacterial liver disease followed the same timeline that the researchers observed when feeding the mice with pure alcohol.
Looking for more evidence that these germs are indeed to blame for fatty liver, researchers transferred intestinal material from mice or humans with NAFLD to healthy mice. When human or mouse intestinal material with NAFLD was transplanted into healthy mice, healthy animals developed fatty liver damage.
The definitive evidence was presented when the researchers treated the gut material obtained from NAFLD mice with a virus that killed only Klebsiella, when the gut material without Klebsiella was transplanted into healthy mice, they did not develop any disease.
The results for the first time suggest that some K. pneumoniae bacteria produce excessive amounts of alcohol, which can lead to oily liver. This suggests that some cases of K. pneumoniae pneumonia may be treatable with antibiotics. This worked when mice with K. pneumoniae-induced fatty liver were treated with the antibiotic imipenem, which reversed the disease progression. Because K. pneumoniae bacteria convert sugar into alcohol, doctors may soon be able to diagnose this form of oily liver with a simple blood test to measure blood alcohol levels in response to sugar. Yuan and her team showed that mice that care for the alcohol-producing bacterium Klebsiella become inbred and show increased levels of alcohol in the blood after consumption of sugar.
These are exciting discoveries. However, since all participants in the study are from a Chinese cohort, it is unclear whether the phenomenon is widespread. Klebsiella bacteria are usually found in the human gut, but it is unknown why some people harbor strains that produce high levels of alcohol.
In the larger picture, the study further illustrates the importance of the microbiome in regulating mood and behavior. Some people may have intestinal germs that release alcohol, which can make them behave as if they were drinking when in fact they were eating only sweet dessert, as was the case with a DUI woman. Another interesting question that arises is whether these people are more tolerant of alcohol because they would be exposed to it constantly.
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This article was republished by The Conversation under a Creative Commons license. Read the original article here: http://theconversation.com/gut-microbes-can-get-you-drunk-and-damage-your-liver-123741. evidence19659022]