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A Caesar mother does get a stat of antibiotics before opening. In crash caesars this would barely have time to distribute; normal operating procedure calls for

A Caesar mother does get a stat of antibiotics before opening. In crash caesars this would barely have time to distribute; normal operating procedure calls for the dose to occur 30 min to 1 hr before skin incision though. You have a bit of a misunderstanding here - a baby does not have a microbiome in the womb - it is a sterile environment

trhway 7y ago
>You have a bit of a misunderstanding here - a baby does not have a microbiome in the womb - it is a sterile environment no. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350424/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350424/ "The first, and most important, contribution to the genesis of the microbiome is vertical transmission of maternal microbiota. Colonization of mucosa in the digestive, respiratory, urogenital tracts, as well as the skin begins at, or perhaps even before, the time of birth when a newborn is exposed to a mother’s microbiota. It was previously thought that the in utero environment was largely sterile and that a fetus was not colonized with bacteria until the time of birth. Recent studies suggest the presence of a microbiome within the placenta as well as fetal meconium, suggesting that the colonization process begins well before delivery. " And my point is that the "most important, contribution to the genesis of the microbiome" probably gets hit with the antibiotics given for C-section.
- robbiep 7y ago
  Thanks. This is new knowledge since I was at medical school. The paper you link however is not at all convincing. A better paper here: https://www.frontiersin.org/articles/10.3389/fmicb.2019.01124/full https://www.frontiersin.org/articles/10.3389/fmicb.2019.0112... Does a better job of explaining things. Interestingly the species isolated are highly homogenous - https://www.frontiersin.org/files/Articles/454989/fmicb-10-01124-HTML/image_m/fmicb-10-01124-g001.jpg https://www.frontiersin.org/files/Articles/454989/fmicb-10-0... Most samples had only a single species isolated from meconium; Controlling for sources of contamination it looks like out of the sample of 43 there were several that would meet the classification of a sterile environment. So, I was wrong; but so are you
  - trhway 7y ago
    I'm not insisting on specific source of bacteria. I mentioned it only as illustrative detail/example, and it only distracted (who knew that here would be a medical professional for whom getting such details right is naturally important - the same way like it is very distracting for coders when movies get computers related details wrong :) from the main point that baby coming out of C-section may have antibiotics in him/her which would screw with whatever gut microbiome "priming" scenario pre-/post- delivery he/she would be going through.
    - robbiep 7y ago
      I take your point but it’s not binary - in the sense that I have strong doubts that the MIC (Minimum inhibitory concentration) of antibiotics would touch much of a colonisation in a neonate should it be present. Having a single dose of abx in an adult doesn’t kill everything; the intent of a pre-surgical dose of abx is because evidence shows it significantly reduces post op infections; and the antibiotic used is active primarily against gram positives (cephazolin 1-2g) whereas Pelomonas puraquae is a gram negative anerobic rod and more than likely not going to be touched, even if the MIC is reached (and my experience of obstetric theatres is the antibiotic usually (80% of the time) goes in only minutes before skin incision. So; a couple of things: - presuming no contamination in the study, the primary coloniser of neonates appears to be a gm -ve rod - antibiotics given for caesars are active against gm +ves /aerobes So while there may be a mechanism, it’s not highly plausible in light of the other known mechanisms affecting Caesar births vs natural (ie bacterial microbiome pickup during traversal of the birth canal) about which there is significant evidence regarding immune priming

trhway 7y ago

>You have a bit of a misunderstanding here - a baby does not have a microbiome in the womb - it is a sterile environment no. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350424/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350424/ "The first, and most important, contribution to the genesis of the microbiome is vertical transmission of maternal microbiota. Colonization of mucosa in the digestive, respiratory, urogenital tracts, as well as the skin begins at, or perhaps even before, the time of birth when a newborn is exposed to a mother’s microbiota. It was previously thought that the in utero environment was largely sterile and that a fetus was not colonized with bacteria until the time of birth. Recent studies suggest the presence of a microbiome within the placenta as well as fetal meconium, suggesting that the colonization process begins well before delivery. " And my point is that the "most important, contribution to the genesis of the microbiome" probably gets hit with the antibiotics given for C-section.

robbiep 7y ago
Thanks. This is new knowledge since I was at medical school. The paper you link however is not at all convincing. A better paper here: https://www.frontiersin.org/articles/10.3389/fmicb.2019.01124/full https://www.frontiersin.org/articles/10.3389/fmicb.2019.0112... Does a better job of explaining things. Interestingly the species isolated are highly homogenous - https://www.frontiersin.org/files/Articles/454989/fmicb-10-01124-HTML/image_m/fmicb-10-01124-g001.jpg https://www.frontiersin.org/files/Articles/454989/fmicb-10-0... Most samples had only a single species isolated from meconium; Controlling for sources of contamination it looks like out of the sample of 43 there were several that would meet the classification of a sterile environment. So, I was wrong; but so are you
- trhway 7y ago
  I'm not insisting on specific source of bacteria. I mentioned it only as illustrative detail/example, and it only distracted (who knew that here would be a medical professional for whom getting such details right is naturally important - the same way like it is very distracting for coders when movies get computers related details wrong :) from the main point that baby coming out of C-section may have antibiotics in him/her which would screw with whatever gut microbiome "priming" scenario pre-/post- delivery he/she would be going through.
  - robbiep 7y ago
    I take your point but it’s not binary - in the sense that I have strong doubts that the MIC (Minimum inhibitory concentration) of antibiotics would touch much of a colonisation in a neonate should it be present. Having a single dose of abx in an adult doesn’t kill everything; the intent of a pre-surgical dose of abx is because evidence shows it significantly reduces post op infections; and the antibiotic used is active primarily against gram positives (cephazolin 1-2g) whereas Pelomonas puraquae is a gram negative anerobic rod and more than likely not going to be touched, even if the MIC is reached (and my experience of obstetric theatres is the antibiotic usually (80% of the time) goes in only minutes before skin incision. So; a couple of things: - presuming no contamination in the study, the primary coloniser of neonates appears to be a gm -ve rod - antibiotics given for caesars are active against gm +ves /aerobes So while there may be a mechanism, it’s not highly plausible in light of the other known mechanisms affecting Caesar births vs natural (ie bacterial microbiome pickup during traversal of the birth canal) about which there is significant evidence regarding immune priming