against ulcers and cancer . But certainly , one helicobacter is not equivalent to another helicobacter . And certainly , one faecal bacterium prausnitzii is not the same as another faecal bacterium . And definitely , one clostridium is different to another clostridium , as we know . But how we ' re sub-typing the many thousands of different species and then looking at how they exactly cause dangerous problems and toxins , and how you would differentially treat them is going to be I think not super productive . I think if you do find certain organisms like clostridium difficile , you will try and eradicate it without really being cognisant of exactly how dangerous the strain is .
Andrew : So let ' s talk a little bit about gut microbial development . You know , we used to think that the baby was sterile in-utero and that the totality of the baby ' s microbiome developed from the vagina of the mother . But then there was recent evidence , I think , University of Madrid , showing this enteromammary pathway , that the breastfeeding was actually very important in translocation , that there was active transport by monocytes of bacteria from the mother ' s gut through the lymph , through the breast milk into the baby . So what ' s the understanding now of the development of the microbiome ?
Johan : I think the understanding is that in utero , we ' re mainly like germfree animals . And then the minute the baby comes out , it ' s exposed to this universe of microbial , just extraordinary diversity . And we know , for instance , that breastfeeding changes the baby ' s microbiome , vaginal delivery changes the microbiome , home birth changes the microbiome , caesarean section has a profound effect on the microbiome . But I don ' t think we should overinterpret these data . Because I think , basically , your microbiome , by about the age two or three seems to be fairly stable , and it seems to be very similar to the siblings and the people that you grow up with . So what initiates the microbiome clearly is your first contact as you come out of the uterus . Whether that is in a hospital environment , or in a tiny house in a rural community will obviously change it . If one has to choose , let ' s say a better microbial signature , it would probably be ideal to be born perhaps having a home birth in a rural African community , those are the best microbiomes one can have .
The worst microbiome you can be born with , I would imagine would be a caesarean section microbiome where you get born into a sterile theatre , with very little variability of organisms . But that sort of evens out with diet when you get whole food , when you get weaned off the breast . And I ' m not sure that is fantastically important in the bigger picture . I think it is important exactly when babies are weaned , I think it ' s very important what diet they get . And I think the most important perhaps , is , in what sort of sterile environment babies get raised . We know that the more sterile your environment is , probably the higher chances of getting inflammatory bowel disease .
There ' s been long term data emerging that the further north you go from the equator , the higher your incidence of inflammatory bowel disease is , in particular , Crohn ' s disease . And it may be that it is simply a side effect of living in an equatorial , more developing country with a rural sort of diet , you get a fantastic microbiome . If you eat African type food , you get a great microbiome . The worst sort of food you can eat is the western-type , refined food . And the worst lifestyle you can have is the western-type , sterile-type lifestyle where you don ' t as a baby get involved in the dirt and the chickens , and the goats , and things like that .
So I think that ' s an important thing to think about . I think one has to have a varied microbiome . And that ' s achieved by eating a sort of a diet rich in fibre and rich in natural-type foods . There ' s been a very interesting study done with African Americans and African Africans and the study looked specifically at cancer . And we know that African Americans have a very high incidence of cancer and that ' s been related [ to the microbiome ]. The whole cancer thinking in bowel cancer has somewhat changed , [ in ] that it could start with inflammation . And that the inflammation could be initiated by an abnormal microbiome and the African Americans have quite a poor microbiome , they seem fairly dysbiotic . Whereas the African Africans have a fantastic microbiome . Different Africans living in different places , obviously .
If you live in a deeply urbanised environment , like Johannesburg , you ' d have a very different microbiome to someone living in Tanzania , living sort of a hunter-gatherer lifestyle or living on a small farm in Tanzania . But if the African Americans change their diets to the African-African type of diet , which is high in fibre , low in western processed foods , they can within two weeks change their microbiome into really quite a good microbiome . So microbiome changes with diet , and with exposure to things in your environment . It happens quite quickly and it can be profound . And the other side of the coin is the African Africans , when they ate McDonald ' s and drank Coke … their microbiome became horrible . I think that ' s interesting . Having a microbiome it ' s not a life sentence , you can change your microbiome .
The microbiome and autism *
Can I just quickly say something about autism . It feeds into this brain-gut axis . So we know that the brain talks to the gut , but we also know the gut talks to the brain . And we know it does it through substances that are made by the microbiome . And we know that it ' s via the vagus nerve . So the vagus nerve in a sort of a reverse communication speaks to the brain . And there ' s been some extraordinary new data looking at autism . Now , if you look at autism as a disease , it shows us how badly the medical profession has treated patients . So one of the pioneers of autism , Hans Asperger who obviously was one of the first people . But there was a man
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