The paper is about a very specific substance of white blood cells called leukocytes that
you can only find at intra-epithelial lymphocytes that is the skin and your intestine for example
and the main message of the paper is that these cells, the ones in the intestine that
is, need a very specific compound to survive and these component you can find in green
vegetables and so the central message of the paper that eating your green vegetables is
very important for your intestine immune system.
There are several types of immune cells in the intestine and there are several layers
of them.
The first layers are called intra-epithelial lymphocytes and that what destroys the gut.
The exact function is not really known but they are important in maintaining the intra-epithelial
they have an interaction with the intra-epithelial cells and make them grow, that is, the little
structures in your intestines, they constantly turn over because when you digest food they
get damaged and these cells are important in replenishing new cells.
Secondly they are immune cells after all, and they keep some unwanted bacteria at bay
so they don't invade your tissues and cause inflammation.
All the experiments were performed on mice and what we did was feeding mice their standard
diet and looked at the amount of intra-epithelial lymphocytes they harbor in the intestine then
we gave the same very healthy mice a different diet that doesn't contain any vegetable components
and to our surprise all the intra-epithelial lymphocytes or almost all disappeared.
This immune chemistry pictures of part of the intestine and the stain is for immune
cells which are shown in red and we show the epithelial barrier which is shown in green
and we see the wall type from the control mouse and the cells that are there and the
cells are very closely interacting with the intra-epithelial lymphocytes cells and the
next imagine we showed in the absence of vegetables, or in the absence of the hydro carbon cell.
All of these cells have not only disappeared from the epithelial barrier but they are not
visible at all.
The intra-epithelial lymphocytes we studied are very particular sub-set of cells they
are made in the embryo already so the theory maybe their development was affected which
turns out not to be case or their migrations they move from a central organ to the intestine
we actually find the cells are migrating properly and they arrive in the organ but they then
disappear so it turns out that the green vegetable component is necessary for the survival of
these cells without them they die.
This is our model this is a graphical representation of the gut the finger like structure you see
on the left in the gut you have intra-epithelial lymphocytes highlighted here in blue and these
are the cells which express the aryl hydrocarbon receptor.
This receptor gets stimulated by the compound found in green vegetables and as a consequence
these cells perform their function they provide growth factors for the epithelial cells to
turnover and they do the immune surveyance and as a consequence of that you have few
but sufficient amount of bacteria here surrounding the intestine.
The absence of green vegetables the intra-epithelial lymphocytes arrive in the guts but they die
as a consequence the finger like structures are healthy looking these is no epithelial
surveillance so the build up of bacterial is much greater so you see all these little
things around the ville structure and to keep those bacteria at bay we get other white blood
cells called t-cells migrating into the ville and providing an inflammatory environment.
Well the intestine is full with bacteria with very good bacteria and less good bacteria
and one of the things we see in ageing people is that the amount of risk of infection goes
up.
This intra-epithelial lymphocytes are very important in maintaining the balance between
good bacteria and not go good bacteria so we think eating your 5 portions of green vegetables
a day would really help maintaining a very healthy intestinal flora and that will be
very beneficial for a long life.
The research was carried out at the National Institute for Medical Research with funding
from the Medical Research Council all the Welsh work was performed there in addition
the second part of the project was performed at the Babraham Institute in Cambridge which
gets its funding from the BBSRC.
The Babraham Institute, near Cambridge, in the UK undertakes innovating, world-leading,
life-sciences research to generate new knowledge of the biological mechanisms underpinning
ageing, development and the maintenance of health.
The Institute is at the heart of the Babraham Research Campus, which is also home to around
thirty early-stage bioscience companies, underscoring BBSRC's and Babraham's commitment to support
innovation, knowledge exchange and wealth creation in the UK.