Does Drinking Alcohol Kill Your Gut Bacteria?

Does Drinking Alcohol Kill Your Gut Bacteria?

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

100 Replies to “Does Drinking Alcohol Kill Your Gut Bacteria?”

  1. Alcoholics never get ill, at least not until their liver packs up. But it is a thing, alcoholics never get ill, having a lot of alcohol in your body is a type of chemotherapy where everything and anything dies because of it but humans are bigger and more resistant than single-celled organisms are and so we gradually repair from alcohol damage over time or just accumulate it in our system but Johnny-bacteria snuffs it because our body is inhospitable to him.

    I've been a binge drinker for decades and I've never been ill in my life, whenever there is a bug going around it bypasses me completely while my friends and family end up with the sniffles and days off work, likely because every weekend or every other weekend I get absolutely, utterly and completely shitfaced on whatever spirit is going cheap. The last time I had a cold I think I was a teenager, I'm now 37.

    It's not big, it's not clever, but it's also not hurting me and in a way is helping, thanks to this video a suspicion I have had for years is confirmed.

  2. I'm surprised that you didn't mention the recent announcement by the oncologist association that alcohol consumption, at any level, increases cancer risk.

  3. I had H. pylori when I was about 10, and back in the 90's they didn't think kids could have problems like that so I got sent to therapy instead. By the time they figured it out my stomach was a mess (still kinda is) but i was lucky not to get an ulcer. Did find out i was allergic to penicillin tho. ……

  4. a couple of beers a day is moderate drinking? BRO, on an information channel, giving out terrible and inaccurate information.. Id love to see you drink a couple beers a day for 2 months, and tell me you're feeling good.

  5. So kids should start drinking to prevent a noroviris
    Edit: I'm not serious all I know is that a noroviris sucks and nobody wants it

  6. 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.”



  7. 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.

  8. 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)

  9. 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…

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

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

  12. 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

  13. 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.

  14. 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

  15. 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.

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

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

  18. 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

  19. '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.'

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

  21. 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."

  22. 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.

  23. 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.

  24. 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

  25. 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

  26. 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

  27. 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.

  28. 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.

  29. 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.

  30. 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

  31. 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.

  32. 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

  33. 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.

  34. 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.

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