Where do bacteria in our body come from?

In summary, gut bacteria come from the environment and are beneficial if they are introduced early enough in life. They get attacked by our immune system, depending on what they do to trigger it.
  • #1
hivesaeed4
217
0
We know that a lot of bacteria are present in our body like in our stomach etc. Where do they come from? It's hard to think that at fertilization there is information stored somewhere in the fertilized egg that these bacteria are to be produced which will help in digestion. In other words they probably have to come through the environment. Thoughts?

By the way if they do come through the environment, why are'nt they attacked by the immune system?
 
Biology news on Phys.org
  • #2
I believe (not sure about this) that the initial inoculation of gut bacteria comes from your mother. We were told that this is one of the advantages of breast-feeding. After a population of bacteria is introduced, of course they multiply in your gut. I think your immune system doesn't start up immediately after birth, so these beneficial bacteria can get classified by your immune system as part of "self". I'd be interested to hear other comments on whether this is correct.
 
  • #3
Is this a chicken-and-egg question?

The symbiotic fauna/flora/things (for example) in our bodies do get attacked by our immune system - depending on what they do to trigger it. They enter our bodies in the womb or soon after we are born and during birth itself.

These organisms have evolved with us into a symbiotic relationship over a very long time. If they were not good at getting into us, and living there, they would not be symbiotic.

@phyzguy: babies immune systems get supercharged just after birth - it's just not all their own. Their own system has to learn to recognize new threats and respond properly but is already capable of responding to a wide range of challenges - including controlling their own gut bacteria.

I keep reading, but having trouble confirming, that gut bacteria is often transferred from the mother's anus during a vaginal birth. It is certainly what all the newborn health books said when we had our son.

Antibodies also cross the placenta and linger for some months after birth. They also get a regular top-up of antibodies and lymphocytes in the breast milk.
 
Last edited:
  • #4
hivesaeed4 said:
We know that a lot of bacteria are present in our body like in our stomach etc. Where do they come from? It's hard to think that at fertilization there is information stored somewhere in the fertilized egg that these bacteria are to be produced which will help in digestion. In other words they probably have to come through the environment. Thoughts?

By the way if they do come through the environment, why are'nt they attacked by the immune system?

My understanding is that gut flora primarily get there from eating. And yes, those bacteria have to survive the passage. Lactobacillus acidophilus is a common dietary supplement, for example.
 
  • #5
Thanks.
 
  • #6
Yes, this is what advertisers of probiotic yoghurt like to call ‘friendly’ bacteria. But that isn’t quite the correct understanding. As Simon Bridge said, the correct term is ‘symbiotic’ relationship, which basically just means mutually beneficial. The enzymes the bacteria produce to allow them to access certain nutrients in the food we eat, also help us to access nutrients as well. But it wasn’t ever thus. There were some generations of what Sean Carroll calls an ‘evolutionary arms race’ that took place between our ancestors and those of the bacteria before it settled down into a symbiotic relationship. And that doesn’t mean the bacteria can’t harm us. The same enzymes they produce that help us when produced in our bowel make us very sick if produced in our stomach. The bacteria do not have a direct route from the bowel to the stomach. Enough said about their usual route to get there if I say, make sure you wash your hands properly after using the toilet!
 

1. Where do bacteria in our body come from?

Bacteria in our body can come from a variety of sources, including the environment, other humans, animals, and even our own body. Some bacteria are introduced into our bodies through the food we eat, the air we breathe, or the surfaces we touch. Others are naturally present in our bodies, such as the bacteria in our gut that help with digestion.

2. Are all bacteria harmful to our body?

No, not all bacteria are harmful to our body. In fact, many bacteria are beneficial and necessary for our health. These include the bacteria in our gut that help with digestion and the bacteria on our skin that protect us from harmful pathogens. However, some bacteria can cause infections and make us sick, so it's important to maintain a balance of good bacteria in our body.

3. How do bacteria enter our body?

Bacteria can enter our body through various routes, such as the mouth, nose, eyes, and cuts or wounds on the skin. They can also be transmitted through direct contact with an infected person or by consuming contaminated food or water. In some cases, bacteria can also enter our body through the air we breathe.

4. How do our bodies fight off harmful bacteria?

Our bodies have a natural defense system to fight off harmful bacteria. This includes our immune system, which produces antibodies to target and destroy harmful bacteria. Our skin also acts as a physical barrier to prevent bacteria from entering our body. Additionally, good bacteria in our body can compete with harmful bacteria for resources and limit their growth.

5. Can we get rid of all bacteria in our body?

No, it is not possible or desirable to completely get rid of all bacteria in our body. As mentioned earlier, some bacteria are necessary for our health and well-being. Additionally, our body has a natural balance of good and bad bacteria, and disrupting this balance can lead to health issues. It's important to maintain good hygiene practices and a healthy lifestyle to keep the bacteria in our body in check.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
4
Views
337
  • Biology and Medical
Replies
14
Views
5K
  • Biology and Medical
Replies
2
Views
3K
Replies
1
Views
1K
Replies
2
Views
890
  • Biology and Medical
Replies
1
Views
2K
  • Biology and Medical
Replies
9
Views
2K
  • Biology and Medical
Replies
21
Views
3K
  • Biology and Medical
Replies
19
Views
2K
  • Biology and Medical
Replies
2
Views
1K
Back
Top