Our intestinal tracts are hotbeds of bacterial activity, some of which are dangerous. It can be very dangerous to consume some of these bacteria by mouth, which is why we are taught to be careful about personal hygiene.
If there are dangerous bacteria living in our intestinal tracts as a matter of course, how did they get there to begin with? Were they bequeathed to us in the womb by our mothers? Do we all have early bouts of food poisoning that “impregnate” us with these bacteria?
The quick and dirty (highly simplified) answer here is that you swallow the bacteria that your intestinal tract needs. Newborns don’t have the bacteria to produce vitamin K at first, so they get a Vit K injection soon after birth. By the time the baby’s body needs more Vitamin K, the bacteria are in place.
That makes sense to me as to bacteria that are not dangerous when consumed by mouth. But what about the dangerous ones?
Or, perhaps I am mistaken in my belief that such dangerous bacteria reside in our guts as a matter of course. (That would help explain why my dog doesn’t necessarily get ill when he gets a little “confused” about what is and is not an appropriate food.)
I gave a Vitamin K injection to a newborn yesterday. It’s standard in my area. Of course, parents can refuse but I haven’t seen it. YMMV.
It might be useful to define what you mean by ‘dangerous’. All the micro-organisms living on or in our bodies have the potential to be ‘dangerous’, it just depends where they are. E. coli (the normal non-haemorrhagic/toxigenic/invasive type) is perfectly safe for us to have in the gut, you would expect to find it there in most healthy people. However, get some of those same ‘harmless’ E. coli in the blood or csf, and you’ve got a potentially fatal illness, in the urinary tract and you’ve got an unpleasant and potentially serious infection.
You’ll probably find most of the bacteria we have in our gut are present in food, or are commonly found in the environment. As babies we put almost everything we come into contact with into our mouths, and this is how we inoculate our guts.
E. coli is exactly what I was thinking about. I understand we have it in our guts and, as long as it stays there, it is harmless. But it is considered dangerous when consumed by mouth. So how did the E. coli bacteria get into my gut to begin with? Is it because it is generally safe to consume E. coli because it will not generally migrate into the bloodstream or cerebrospinal fluid (had to look “csf” up!), and I “safely” consumed some when I was a baby?
E. coli (the non-pathogenic type) isn’t dangerous to consume by mouth.
What you want to avoid is consuming any of the pathogenic types (ETEC, EIEC, EPEC and EHEC) which have nasty virulence factors (exotoxins and such).
The majority of the E. coli that you encounter in the environment is going to be the non-pathogenic variety, but because the effects of the pathogenic types are so severe, we try to minimise our exposure to all types of it (e.g. by washing our hands after using the loo, and before eating).
Got it. So would it be fair to say that all of the bacteria that live in our gut as a matter of course (non-pathogenic) are safe to consume by mouth, and that’s how they got there?
Pretty much. As far as “safe to consume by mouth”, I wouldn’t be drinking a culture of any of them, but swallowing a few won’t kill you.
Many ‘dangerous’ bacteria are indeed essential bacteria. Sometimes someone else’s essential bacteria is consumed by you, and your body reacts to this invader and you get sick. Your body is then immune to it.
People living together can become immune to eachother’s bacteria after initial exposure.
One of the reasons anibiotics can make you suffer digestive trouble is because they can wipe out too many bacteria, such as those key to digestion. Sometimes ‘probiotics’ are needed to replace the bacteria that were wiped out.
No.
The antibiotics will affect the gut flora, and often cause imbalances (the flora of the gut is like an ecosystem, it’s a very delicate balance between a number of species) that allow pathogenic bacteria to gain a foothold where they would have previously been out competed by the commensal organisms (that is the organism that should be there).
The loss of bacteria itself doesn’t cause the problems, it’s what replaces them.
As for replacing them using ‘probiotics’, it’s been found that the concentrations of bacteria in ‘probiotic’ drinks varies so greatly, and in some cases is so low as to make them worthless.
No. No single type of bacteria live in our gut as “a matter of course.” I’ve seen estimates of 40 - 200 species at any given time. Which ones are exclusively a matter of your diet and your environmental exposure (which includes exposure to other people). Their number and makeup change constantly, probably with every meal. That’s why unexpected symptoms, like diarrhea, seem to come out of nowhere and disappear just as fast.
There are many strains of E. Coli and every other type of bacteria. They are constantly changing, adapting and mutating, which makes it difficult for our systems to combat them effectively. A new strain could make you sick whether or not you’ve been exposed repeatedly before.
Bacteria play next to no role in digestion. You may get some extra vitamins from them, and they may cause symptoms from undigested sugars from dairy and legumes, but digestion is almost exclusively a function of the digestive enzymes made in the gut, with the vast majority of digestion (defined as breaking fats, sugars and proteins down to their basic components) taking place in the small intestine. (Absorption continues in the large intestine but that’s mostly water.) A bit of an overgeneralization but close enough.
Antibiotics do wipe out intestinal bacteria, but that does nothing at all to digestion. It may cause symptoms because some of the beneficial bacteria that digest the sugars are absent, but that’s a very different physiological function. Probiotics can replace these bacteria. So can cultured products like yogurt. I’ve no doubt that some probiotics are worthless but they’re so cheap and easy to make that finding useful ones is as easy as going to a store.
Try replacing your ‘No’, with “Allow me to elaborate”.
Wow, you talk about pushing it. Let’s see, certain flora gain a foothold because others are reduced in numbers. Okay, that jives with my original overview.
Sorry… it wasn’t meant the way I think you interpreted it.
Additionally,if there’s E. coli there may be some other truly pathenogenic microbes present, especially if the source was human, um, waste. That’s a big reason why we look for fecal coliform bacteria (which include E. coli) in drinking water, near beaches and other places. It’s not that the coliform are so bad, but they usually indicate raw sewage, which could have all kinds of horrible little beasties in it at lower concentrations (but enough to make you sick if you ingest them).