# When an infant is born, is there air in his stomach and intestines? **URL:** \ **Category:** Factual Questions\ **Created:** [September 3, 2022, 10:02pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903 "2022-09-03T22:02:36Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [September 3, 2022, 10:02pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/1 "2022-09-03T22:02:36Z")
I’m talking about the open spaces that in children and adults are filled with air. But that doesn’t seem likely for a being that’s conceived in an essentially liquid environment. How does it happen that the lumen is not filled with some liquid? Or is it? Is that what meconium is? Similar to the question of how does a pumpkin grow with a body filled with air? ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [September 3, 2022, 10:22pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/2 "2022-09-03T22:22:53Z")
Meconium is fetal stool, formed from swallowed amniotic fluid which mixes with fetal intestinal secretions (which are chock-full of shed cells). Amniotic fluid also fills the lungs and many other potential air spaces. No air is present in fetal lungs/bowels etc as a rule, unless some sort of gas-forming process is occurring, usually a deadly infection. Passage thru the birth canal during delivery squeezes out the fluid in the lungs and prepares the newborn to refill the lungs with air. C-section babies tend to need more vigorous respiratory stimulation at birth due to their lungs tending to have more fluid in them. I’ve not delivered any pumpkins so can’t comment there. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [September 3, 2022, 10:37pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/3 "2022-09-03T22:37:28Z")
The GI tract is also supposed to be sterile; it takes several days for the gut to colonize with bacteria that aids in the digestion of milk and the production of vitamin K. The bacteria is obtained through breathing room air, and also from the nipple, whether it’s Mom’s or one attached to a bottle. This is true for mammals in general, and since Qadgop mentioned c-sections, animals delivered that way have a very high risk of death for precisely that reason. I follow several kitten rescue cams, and this is only a very last resort. ---
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [September 3, 2022, 10:37pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/4 "2022-09-03T22:37:44Z")
> [@Qadgop\_the\_Mercotan](#): > > I’ve not delivered any pumpkins so can’t comment there. Bang! Thread winner in one! You sure? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [September 3, 2022, 11:15pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/5 "2022-09-03T23:15:39Z")
> [@CC](#): > > Similar to the question of how does a pumpkin grow with a body filled with air? I don’t know if this is a sub-question you wanted answered, but: Pumpkins grow Pumpkins are not completely airtight ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [September 4, 2022, 1:30pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/6 "2022-09-04T13:30:09Z")
Not too much to add except to point out that it doesn’t take very long for the air to get there after birth. By ten minutes or so there is air in the stomach, within a few hours the small intestines have bubbles and the large intestines by half a day. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 4, 2022, 3:11pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/7 "2022-09-04T15:11:41Z")
> [@CC](#): > > I’m talking about the open spaces that in children and adults are filled with air. That would be the lungs. And so far as I know, only the lungs. Why would the stomach and intestines be filled with air, instead of just empty? ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [September 4, 2022, 4:25pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/8 "2022-09-04T16:25:56Z")
> [@DSeid](#): > > and the large intestines by half a day. I thought large intestines have obligate anaerobes, and the large intestine in general is anaerobic ! ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [September 4, 2022, 5:42pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/9 "2022-09-04T17:42:39Z")
Even the fetus has gut bacteria [and it’s transmitted from the mother](https://www.sciencedaily.com/releases/2019/10/191023132145.htm#:~:text=A%20study%20in%20humans%20and,is%20transmitted%20from%20the%20mother.) ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [September 4, 2022, 6:49pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/10 "2022-09-04T18:49:26Z")
More response than you may be looking for - First the gas that is in the large intestine within hours is passed down from above. And there is that gas in the large intestine in adults as well as kids. It is however a fairly low oxygen environment, especially in the lumen, with relatively higher oxygen levels near the mucosa. Second the mature microbiome of the large intestine has obligate anaerobes … 90% roughly … 10% is not, The microbiome itself helps to regulate the oxygen level. Third, the newborn large intestine is seeded with aerobic and facultative anaerobic bacteria. These consume oxygen, creating the relatively hypoxic environment that leads to obligate anaerobes predominating later. The process takes several years. > [@Qadgop\_the\_Mercotan](#): > > Even the fetus has gut bacteria [and it’s transmitted from the mother](https://www.sciencedaily.com/releases/2019/10/191023132145.htm#:~:text=A%20study%20in%20humans%20and,is%20transmitted%20from%20the%20mother.) Very interesting. Following the link to the article it appears that the fetal microbiome mostly serves an immune training function and is apparently mostly or completely gone by term, with the gut then seeded after birth, primed for it by this earlier exposure. > [@](#): > > The composition and predicted source of the fetal gut microbiota shifted between mid- and late gestation. Cultivatable bacteria in the fetal intestine were found during mid-gestation but not late gestation. … > > … In summary, we describe the presence of bacterial DNA and viable bacteria in the in utero environment. Although complex mechanisms have evolved to protect the developing mammalian fetus from exposure to pathogens and toxins, the discovery of bacterial signatures in the in utero environment in humans and mice suggests the coexistence of refined mechanisms for controlled fetal exposure to the maternal microbiota. Even transient exposure to bacterial antigens in the fetal environment may provide important evolutionary advantages for early immune maturation Cool! ---
**Author:** ![Arcite](https://avatars.discourse-cdn.com/v4/letter/a/67e7ee/32.png) [@Arcite](https://boards.straightdope.com/u/Arcite)\ **Post date:** [September 4, 2022, 7:42pm UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/11 "2022-09-04T19:42:49Z")
Our stomachs and intestines aren’t filled with air. It would be easy to get that impression looking at anatomical diagrams in which these structures are depicted as appearing “full,” but in reality, when they’re empty, they’re just collapsed on themselves, like a balloon. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [September 5, 2022, 12:12am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/12 "2022-09-05T00:12:48Z")
> [@Mangetout](#): > > Pumpkins are not completely airtight Apparently they are watertight because I’ve seen videos of them being used as [boats](https://youtu.be/a4YlHzBF07k). ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [September 5, 2022, 12:37am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/13 "2022-09-05T00:37:07Z")
But that’s over a few minutes. Would water make it through over the course of a few months? Better question: Would a pumpkin grown underwater be filled with air or water (presuming it could actually grow underwater)? ---
**Author:** ![Euphonious\_Polemic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/euphonious_polemic/32/3002_2.png) [@Euphonious\_Polemic](https://boards.straightdope.com/u/Euphonious_Polemic)\ **Post date:** [September 5, 2022, 12:45am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/14 "2022-09-05T00:45:28Z")
What if you put the pumpkin on a treadmill? Underwater? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [September 5, 2022, 1:40am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/15 "2022-09-05T01:40:56Z")
Serious musing: does the air inside a pumpkin originate from outside or by way of cellular respiration, both of the plant’s cells and of commensurate organisms? I suspect the latter. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [September 5, 2022, 1:53am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/16 "2022-09-05T01:53:09Z")
Trying to answer my own musing I found this for a different but likely comparable hollow fruit, bell pepper. [http://www.madsci.org/posts/archives/2006-07/1152918612.Bt.r.html](http://www.madsci.org/posts/archives/2006-07/1152918612.Bt.r.html) The gas composition inside the fruit is different than outside air, significantly higher in CO2, produced by cellular respiration. The inside of a fruit in fact is fairly air tight! That underwater pumpkin would be filled with air. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [September 5, 2022, 1:59am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/17 "2022-09-05T01:59:59Z")
> [@Arcite](#): > > Our stomachs and intestines aren’t filled with air. It would be easy to get that impression looking at anatomical diagrams in which these structures are depicted as appearing “full,” but in reality, when they’re empty, they’re just collapsed on themselves, like a balloon. I was with you until the analogy with a balloon… 🙂 ---
**Author:** ![Arcite](https://avatars.discourse-cdn.com/v4/letter/a/67e7ee/32.png) [@Arcite](https://boards.straightdope.com/u/Arcite)\ **Post date:** [September 5, 2022, 2:16am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/18 "2022-09-05T02:16:17Z")
Well, I thought of a whoopee cushion too, but felt that given that we’re already talking about intestines, the resultant fart jokes would be too distracting. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [September 5, 2022, 7:41am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/19 "2022-09-05T07:41:17Z")
Not sure the conclusion necessarily follows there. My car isn’t airtight, but if I fill it with people who consume the oxygen, the CO2 level will rise inside. All that is necessary for that to happen is that the rate of respiration is out of pace with the rate at which gas is exchanged with the outside. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [September 5, 2022, 10:55am UTC](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903/20 "2022-09-05T10:55:51Z")
Fair point. [Next page](https://boards.straightdope.com/t/when-an-infant-is-born-is-there-air-in-his-stomach-and-intestines/970903.md?page=2)