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Does Drinking Alcohol Kill Your Gut Bacteria?

October 18, 2019

From the hand sanitizer at your favorite food
truck to those single-use wipes at the doctor’s office, alcohols are used to disinfect things
all the time. So every time you have an alcoholic drink,
it’s basically like microbe-killing juice… which doesn’t sound so great for the helpful
critters in your gut. But, turns out, drinking in moderation could
actually kill the microbes that cause food poisoning and diarrhea, while helping the
bacteria that help you. It’s been known for centuries that alcohols
can kill microscopic germs—the Greek physician Galen used wine to clean gladiatorial wounds
way back in 150 CE. But the ethanol in beer and wine is just one
type of alcohol. Chemically, alcohols are compounds with at
least one hydroxyl group, which is just a hydrogen and an oxygen, bound to a chain of
at least one carbon . High concentrations of alcohol—like the
70% isopropanol in antibacterial wipes—dissolve cell membranes, killing bacteria and viruses
on contact. But a straight shot of vodka is only about
40% ethanol, while the average glass of wine is 12%, and beer is 5%. Even though they’re below membrane-nuking
concentrations, lots of drinks can kill bacteria and viruses. But exactly how is less clear. We know that lower concentrations of ethanol
can still make cell membranes unstable. And they can promote the production of reactive
oxygen metabolites, which can damage important cell parts. So alcohol can knock out some unwelcome microbes
in your stomach and upper intestine before they become harmful. For example, there’s pretty good evidence
that beer and wine take out Vibrio cholerae—the bacterium that causes cholera, a disease where
you’re attacked by uncontrollable diarrhea. That could be part of why alcohol was so popular
on long sea voyages, and not just for Captain Jack Sparrow-types: it was safer to drink
rum or beer than probably-contaminated water. Booze doesn’t just kill cholera, either. Case studies have shown that wine, in particular,
might be able to kill the nasty bugs that cause food poisoning like Salmonella and Norovirus,
before they set up shop in your bowels. And one study on around 80 people found that
drinking wine and other beverages with more than 10% alcohol kept people from being infected
with hepatitis A from contaminated oysters, which can cause liver disease. Of course, we now know that there are also
beneficial bacteria that live on and inside us, and you wouldn’t want to kill a bunch
of them with every shot of tequila. So it’s a good thing that doesn’t really
happen, partially because a lot of the microbes that matter are in your colon, not your stomach. By the time your drink mixes with stomach
acid and makes its way through your upper intestines, most of the alcohol is already
absorbed. That said, some scientists think a glass of
wine every night could affect your lower intestines—in a good way. Some of the non-alcoholic compounds in wine
called polyphenols feed helpful bacteria, and get broken into smaller useful molecules. Some scientists think these molecules can
bind to the cell membranes of disease-causing bacteria, like those in the genus Clostridium,
and kill them off. Or they might even boost your health. One study suggested that polyphenol byproducts
could explain why regular wine drinkers seem to have fewer heart problems. And another found that they might help counteract
some of the metabolic problems caused by obesity. But don’t go tapping that keg in celebration
just yet. These potential benefits aren’t a sure thing,
and they refer to moderate drinking—so, like, a glass of wine or a couple beers a
day. Binge drinking and alcoholism are a totally
different ballgame. For example, a fairly large study published
in 2001 found that regularly drinking a little alcohol seemed to reduce the chance of being
infected with Helicobacter pylori, a bacterium that causes severe stomach ulcers. But the researchers found that drinking more
wasn’t better. After a certain point, as alcohol consumption
increased, so did the chance of infection. In fact, the upper intestines in both short
and long term heavy drinkers tend to have too much bacteria. Scientists think that large doses of alcohol
could slow down intestinal movement and take a toll on helpful bacteria, which could give
harmful microbes the time and space to gain a foothold. Alcohol can also mess with the genes in cells
that line your intestines and stomach, which can lead to things like producing too much
or almost no stomach acid after long term abuse. And this isn’t great because stomach acid
is one of the most effective defenses against disease-causing bacteria. Chronic alcohol abuse also cripples your immune
system, making you much more vulnerable to pathogens in general. Not to mention the whole “destroying your
liver” bit. If you picture your gut lining as a sturdy
trash bag made of cells, alcohols and their byproducts can punch a ton of little holes
in it. This lets junk like bacterial toxins leak
out, which your liver has to clean up. And the harder it has to work, the more damaged
it becomes. So a glass of red wine with dinner might actually
help you resist some food poisoning. But if you go overboard, hangovers will be
the least of your concerns. Thanks for watching this episode of SciShow,
which was brought to you by our patrons on Patreon. If you want to help keep the science shots
flowing, order a round on you by pledging your support at


  • Reply Zaman Yolcusu December 10, 2017 at 9:12 pm


  • Reply Page Fault December 10, 2017 at 11:41 pm

    Bust out the everclear baby.

  • Reply Christopher Robin December 13, 2017 at 4:43 pm

    Is it just me or this guy is hot????

  • Reply Brandon Diaz December 14, 2017 at 6:30 am

    A straight shot of vodka is 40% ass.
    However…tequila is 40% bad ass.
    Tequila is life. And a lot of sleep. And a lot of puke. And a lot of death. And a lot of “let’s drink some more of it during & after finals!”

    “Just because you can’t dance doesn’t mean you shouldn’t.”



  • Reply Aaron Vice December 19, 2017 at 1:57 pm

    Half true

  • Reply James Drury December 19, 2017 at 9:23 pm

    Sponsored by Budweiser

  • Reply Buster Jones December 20, 2017 at 8:40 am

    It's kinda hard to die optimistic when there's phonies lying dead on the pavement, please, if you can hear me man, it's hard to make amends but I'm losing my closest homies and friends.

  • Reply iluvpinkandgold December 20, 2017 at 4:50 pm

    See I'm not an alcoholic I'm healthy! ?

  • Reply Wounded Ego December 20, 2017 at 11:29 pm

    Most food poisoning is caused by Salmonella bacteria but not once it is in your stomach. It eats your food when it is left out in the kitchen or dining area and after about 4 hours there is enough of its toxic poop on your food to make you sick. So drinking wine will NOT prevent food poisoning. You would have to pour the wine over your food ever half hour or so to slow it down. Rule of thumb is that if food has been been left out for 4 hours it is covered with Salmonella poop and should be discarded. Don't try to cheat by eating food that's been left out longer than that and washing it down with a drink. If you are travelling, though, for example in Mexico or elsewhere where the tap water contains bacteria that you are not accustomed to then mixing in some wine will kill the bacteria and make it safe: "Stop drinking only water, and use a little wine because of your stomach and your frequent illnesses." – 1 Timothy 5:23 (from the Bible)

  • Reply Wounded Ego December 21, 2017 at 1:25 am

    What about honey? Does it kill gut bacteria?

  • Reply steve gale December 22, 2017 at 4:42 pm

    Okay, but it breaks down the stomach lining which is far from good.

  • Reply CarolinaBaby _ December 22, 2017 at 11:44 pm

    A pint a day keep the doctor away. Wayyyy ahead of ya

  • Reply Jolujo 58 December 26, 2017 at 2:56 pm

    Ear studs are a sure sign of brain damage!

  • Reply Evanjij December 26, 2017 at 6:09 pm

    lol who just drinks a couple beers

  • Reply own plz December 30, 2017 at 9:13 pm

    Loved this. I Wantt to learn More about stomach bacteria!

  • Reply Randy Pullman December 30, 2017 at 11:07 pm

    buzz kill…

  • Reply William Morey-Baker January 1, 2018 at 3:47 am

    just about every claim this video has made is false, taken from cherry picked studies, and out right ignores numerous contradicting studies that were carried out on a much larger scale. much disappointment…

  • Reply Dewey AI January 8, 2018 at 3:10 am

    Gonna have a glass right now

  • Reply Vinny Carwash January 8, 2018 at 7:57 pm

    Pooh, no! That's microbe killing juice!

  • Reply Matthew Beal January 9, 2018 at 1:13 pm

    Just eat grapes.. all the benefit of wine without destroying your liver… or promoting pancreatic cancer, stomach, esophageal cancers, etc .. cheaper too.

  • Reply princess étoile January 11, 2018 at 7:23 pm

    Great information excellent thank u??

  • Reply Screw Crew January 14, 2018 at 9:40 pm

    Thank you!!!!

  • Reply wkangaroo February 20, 2018 at 9:20 pm

    I remember a few years back that bespectacled guy promoting sugar on this show. Now they are promoting booze. This show is a prostitute

  • Reply Rolland Deschain March 14, 2018 at 4:39 pm

    was trying to treat a food born illness I picked up from canned tuna, medical grade anti-biotics didnt do the trick, herbal options weren't working either, had 3 shots of tequila and felt better the next day, was pretty shocked

  • Reply Barry McCockener April 24, 2018 at 11:04 pm

    i got food poisoning a few years ago and since then my stomach gets sick the day after I drink alcohol. my doctor said well don't drink.

  • Reply Joe Morrow April 28, 2018 at 8:56 am

    I mix all alcohol during the week, Red wine, Whisky, Beer, but always eat while I drink,,,love the blue cheese crumbles,,??????4,27,18

  • Reply Otto is not My real Name May 16, 2018 at 3:46 am

    When are scientists going to do a study to show the benefits binge drinking? Just drink your weekly beers all at once, I think it's much more efficient than drinking every day.

  • Reply Kiran M May 28, 2018 at 8:25 am

    Now I am proud Man who drinks alcohol

  • Reply Aaron Wright July 4, 2018 at 2:07 pm

    antibiotics dont mess to much with them, Gut brain axis ya know kill your gut kill youself haha

  • Reply Matthew July 5, 2018 at 6:49 am

    higher ABV alcohols can also dehydrate the bacterial cells, thus killing them. This is the mechanism behind isopropyl alcohol being in hand sanitizer.

  • Reply Money seeker July 6, 2018 at 4:02 pm

    Comments in this video cancerous

  • Reply xxX Xxx July 14, 2018 at 5:42 pm

    Millennials are annoying. Lose the gages they were cool in 2007, they're dead now.

  • Reply Austra Robust July 30, 2018 at 11:46 pm

    Drink your orange juice

  • Reply Sietze van de Burgt August 16, 2018 at 12:13 am

    An aquintance of mine did actually drink a lot had to stop and than after stopping a liver cancer developed !!!

  • Reply Matthew Soroko October 7, 2018 at 1:27 am

    I can't drink alcohol every day. I would get grumpy.

  • Reply knocknockify November 2, 2018 at 5:03 am

    Y’all asking questions I never knew I wanted to ask

  • Reply Derp herd November 7, 2018 at 5:22 pm

    after a heavy night of drinking i get a epic session on the toilet XD,

  • Reply roland kamugisha November 16, 2018 at 7:58 pm

    Be careful with what you tell the public. research is not definitive and some papers have dubious claims. make sure to research your information from respected journals or you run the risk of being sued when some thing goes

  • Reply Corey November 23, 2018 at 3:21 am

    So drinking is good for you this week?

  • Reply LeoCrossChaos December 5, 2018 at 4:39 am

    there are recent studies from the british NHS that suggest that there is NO safe amount of alcohol consumption.

  • Reply Andreas Ranthe December 12, 2018 at 6:59 pm

    'Beer by the way is the worst thing you can ever drink, it's in no way healthy and also people get the munchies when they drink pints(in small amounts) hence the beer belly. people feel sluggish even after one glass of red(in small amounts) the next day, just look at this video The heart benefits of red wine for young people(20s-30s) are marginal, Not big. Some people think alcohol is a sleep aid, it helps you to sleep(temporarily) but then when the effect wears off, you become restless. It affects your body's natural sleeping pattern,.it steals a precious chemical in your body called 'the human growth hormone.'

  • Reply you dxb January 10, 2019 at 7:49 am

    Yessss sure alcohol kill everything in your body execpt bacteria :).
    your kidney. Liver. Teeth. Brain. Sex…… and more

  • Reply brian mundacruz February 11, 2019 at 12:30 pm

    i show this video to my wife everytime i need to go out with my friends

  • Reply Greg Camp February 21, 2019 at 9:20 am

    As the joke goes:

    Teacher pours water into one glass and whisky into another and then drops a worm in each. The worm in water swims around, while the worm in alcohol dies. The teacher asks the class what lesson this offers

    Johnny in the back of the room raises his hand and says, "If you drink liquor, you won't get worms."

  • Reply W S February 22, 2019 at 1:42 am

    which source is it that says alcohol can help prevent getting hepatitis A?

  • Reply Christophe Abiel February 25, 2019 at 3:15 pm

    I'm trash and greatly hated.

  • Reply Marissa van Eck February 26, 2019 at 6:29 am

    It's not worth it. Cook with and consume ginger, garlic, onions, turmeric, and so forth. Alcohol is horribly hard on your liver, which has to detoxify it in preference even to fructose, which is also basically a metabolic poison.

  • Reply Juan Mena March 1, 2019 at 2:03 pm

    I might start to drink booze now.
    I have 26 years old, and I've drank just 6 beers in my entire life.

  • Reply Darrell Cole March 1, 2019 at 9:27 pm

    In 1 Timothy 5:23 Paul tells Timothy to forsake drinking so much water, and to drink a little wine for the stomach's sake and your frequent illnesses. Paul says in another verse to do all things in moderation.

  • Reply 50 Pct Amused March 2, 2019 at 4:26 am

    I quit drinking after learning about cirrhosis.

  • Reply Shane Montgomery March 2, 2019 at 9:18 am

    I learn every time you talk
    Nice jacket

  • Reply E1337Jerk March 4, 2019 at 10:54 am

    Is it just me or is there a glare in his hair

  • Reply GG March 5, 2019 at 6:41 pm

    30 cans every 3-4 days seems to be just right for me. ??

  • Reply Ivan Ooze March 6, 2019 at 11:51 am

    Take it from me, after stomach bleeding cirrhosis sepsis and 2 hip replacements shitting blood and rehab, oh yeah im 28 years young. Just don’t drink to much, you don’t go to Vegas every night don’t drink even a little every night

  • Reply Aries Rogue March 8, 2019 at 5:01 pm

    Dayum……he's fkn Cute??????‍♂️

  • Reply Good Bye March 8, 2019 at 8:33 pm

    Drinking for years now. Haven’t been sick in the past year and a half while all my family and friends get sick year round. Go figure

  • Reply BlueSteel March 10, 2019 at 4:03 am

    I'm beginning to notice that the typography isn't as good as it used to be… still great vid.

  • Reply vidyaWolf March 11, 2019 at 8:53 pm

    HA! I knew my alcohol addiction would save my life one day!

  • Reply LetsPlayCrazy March 15, 2019 at 6:48 pm

    2:43 "[…]refers to moderate drinking[…]a couple of beers a day"
    yeees… "moderate" 😀

  • Reply Jarden Howard March 16, 2019 at 8:30 am

    Honestly at this age I wonder why I even still bother youtubieing things. I already knew the answer and all you did was ramble on about the semantics which for the most part were obvious to begin with. I think I rely on youtube too much over my own knowledge and education. Good video, not hating just saying maybe my generation is addicted to youtubing an answer they may already know #1992

  • Reply antiisocial March 16, 2019 at 1:22 pm

    Yeah alcohol!

  • Reply Erwin Hun March 16, 2019 at 10:08 pm

    Alcohol is harmful. I'm not radically against it, but I think we need to stop fueling the myth that alcohol has health benefits. This is a "doctors for cigarettes" situation where an industry fund research that is supposed to put their products in a beneficial light, while independent research agrees that it is harmful both to your health and to society.

  • Reply Virginia Hansen March 17, 2019 at 8:37 pm

    But why is there hair around my gut bacteria?

  • Reply geekbaritone March 20, 2019 at 6:46 am

    True while in Mexico city I got sick drinking tap water which I did not know you're not supposed to drink was in my mid-teens I had a stomach ache was really bad and diarreah. My host mother gave me 2 shots of straight tequila fixed it right up within minutes.

  • Reply Thomas Wilding March 20, 2019 at 1:23 pm

    Interesting, thanks. I find a beer or wine, with food, puts me off my food. So I don't eat as much. I wonder if the observed benefits of a wine or beer with food is to reduce your calory intake? So it would be beneficial because it messes with digestion.

  • Reply Otizzle babe April 11, 2019 at 8:10 am

    You look too young to know anything so your saying alcohol is good for stomach ulcers because i was drinking every day and had to have surgery and to stop drinking. So what are you reall saying

  • Reply Otizzle babe April 11, 2019 at 8:11 am

    Asinine info from a kid

  • Reply Mermaid Melodie April 12, 2019 at 4:10 pm

    But now, researchers are saying that for women, moderate drinking (one drink a day) could increase your overall lifetime risk for breast cancer by 5%.

    Which is it? Good for you in small amounts or none at all? Honestly, I'm not a drinker, but I wish they would make up their minds what they truly want the public to know about alcohol and disease risk.

  • Reply Ryan Air 001 April 14, 2019 at 6:22 am

    Why am I drunk?

  • Reply fds fds April 18, 2019 at 11:30 pm

    I didn't watch the 2nd half but it sounds like I'm benefitting my microbiome heavily every day starting from the moment I wake up

  • Reply Landon Van Arsdale May 12, 2019 at 11:23 pm

    Okay, so just eat more grapes

  • Reply Holl E. H. May 25, 2019 at 1:27 pm

    So you're saying that drinking can help prevent liver disease? That's a first.

  • Reply Roman Vega June 4, 2019 at 2:27 am

    Best alcoholic concentration is between 60 to 90%

    So I'm going to get that Bacardo 151. (75%) ?

  • Reply Hypro escalier June 7, 2019 at 12:57 pm

    drinking 1 bottle of vodka plus 10% = 50% bacteria thanos snap

  • Reply Bears 25 June 10, 2019 at 8:30 am

    It's like taking antibiotics plus drinking sugar bad idea

  • Reply Matfen815 July 19, 2019 at 4:48 am

    Alcoholic apologist

  • Reply Auror Muharremi August 21, 2019 at 8:47 pm

    This is video is not for muslims

  • Reply Zesty Lemon Zach August 24, 2019 at 1:39 am

    0:16 This assumption is way too generalized. Alcohol is totally indifferent to weather or not one of the millions of different strains of bacteria are beneficial to us or not. It has no reason to kill or spare harmful bacteria any more than it has helpful bacteria, you are just picking and choosing to speak of the specific instances where alcohol kills bad bacteria.

  • Reply MINDYWAAAA September 6, 2019 at 11:42 pm

    okay i just want to say that you can obtain more Polyphenols in chocolate, pomegranates and other dark veggies and fruits, (even green tea!). You don't need to drink wine, which can have a higher degree of negative effects on health.

  • Reply Sam S September 7, 2019 at 6:51 pm

    Yeah so….food in excess can cause premature death… anyone for foregoing food?

  • Reply Soldier 1357 September 7, 2019 at 7:33 pm

    Probiotic beer or meade? Very simple use Saccharomyces Boulardii yeast. NO HOPS!

  • Reply A. M. September 23, 2019 at 11:36 am

    Great video!

  • Reply Armando Zessar September 25, 2019 at 12:49 am

    Looks, beer are good to fight bacrerias just because containing yeast, wine instead, are good for driving Colloidal Silver or any antibiotics inside your body, because Bacterias or Mycotoxins likes wine ! In a bad case, adding a bit of grapes spirit , remember don't drive after this.

  • Reply Charlene Downes September 26, 2019 at 9:46 am

    Alcohol kills bacteria? I’m filling my
    Bidet with whiskey. ?

  • Reply Alex Rydin October 2, 2019 at 6:49 pm

    How’d they do a gut health episode without Hank?

  • Reply Heal-Thy Life October 4, 2019 at 11:09 am

    All I know is I'm here bc I had this one drink at a restraurant and my stomach started killing me lol! It disturbed some kinda flora and I have been paying for it for 5 days lol

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