We’re always being told to increase the ‘friendly bacteria’ in our gut, but this leading doctor recommends a much simpler alternative instead
The bacteria living inside you are essential to your immune system
‘Probiotic’ drinks, full of bacteria, claim to have a range of health benefits
But even the experts aren’t entirely sure how helpful these yoghurts are
Dr van Tulleken decided to see how effective the fibre in oats is
After six weeks of eating tons of porridge, the results were compelling
First, a health warning: anyone eating breakfast should skip to the sports section.
In January of this year a group of doctors in Amsterdam published a study using ‘friendly bacteria’ in the most extreme way possible.
They were treating a group of patients with an infection caused by a bacterium called Clostridium difficile (C.diff) – which grows when your normal bowel bacteria are wiped out by antibiotics. It can cause severe diarrhoea and even death.
Ironically the treatment of C.diff infections is usually another strong course of antibiotics, but instead the Dutch group used the ultimate probiotic: a faecal transplantation.
The power of porridge: Dr Christoffer van Tulleken ate oats every day for six weeks to assess the impact on his gut bacteria
That’s right: they took donor faeces from healthy volunteers (screened for every imaginable disease) and infused it via a tube into the patients’ small intestines. The treatment was so effective that the trial was stopped early. It was a small trial, and not without flaws, but it should prompt research in an area of medicine where we are only just beginning to understand our ignorance: the bacteria living inside us.
You are more bacteria than you are human: for every one of your cells, you have at least ten bacteria and most of them live in your gut. For every one of your human genes, you have 200 bacterial genes.
These bacteria living inside you are called your microbiome and they’re not parasites; without them you would die.
We have outsourced some of our most vital functions to the bugs living in us and their influence extends beyond mere digestion; they help us extract up to 30  per cent of our calories from food, especially during early life, so they’re essential for brain development.
They protect us from harmful bacteria, help metabolise drugs, control inflammation and absorb essential nutrients. The bacteria in fat people even seem better able to absorb calories than those found in thin people. Every month more and more functions are found, but the one most of us have heard of is their role as having the largest immune function in the body.
It’s now thought maternal bacteria can cross the placenta, so even before birth a mother’s microbiome directly influences her baby’s. Anyone who’s watched a birth knows it’s not a clean process and babies often start to swallow bacteria from their mothers even as they are being born.
When in the gut, those bacteria start to educate the immune system. One disadvantage of having a Caesarean may be that it prevents this exposure to these vital bugs.
Modern changes in how mothers, babies and children are exposed to bacteria may be one reason for a rise in asthma, allergies and other conditions. The effect of unnecessary antibiotics on the development of this delicate system is not fully understood, but is likely to be detrimental.
Ludicrous: The idea that there could be one simple drink with one simple bug in it that could make us all feel better is farcical
I’m an infectious diseases doctor, so I’m normally interested in destroying ‘bad’ bacteria, but for the BBC2 programme Trust Me I’m A Doctor, I found out more about the ‘friendly’ ones that you have probably heard about through the vague, comforting science of ‘probiotic’ or ‘live’ yoghurt adverts.
A daily dose of these friendly bacteria is claimed to have a wide range of health benefits, but you may find it hard to buy anything called ‘probiotic’ any more because the European Union has decreed something can only be called a probiotic if it has a proven health benefit – and the criteria are very strict.
There is evidence that taking probiotics with particular species of bacteria in them will help in specific situations (such as infectious gastroenteritis, diarrhoea associated with taking antibiotics, or irritable bowel syndrome).
Even for an expert, knowing what to take can be very hard. Dr James Kinross is a surgeon at Imperial College London and is doing some of the most exciting research in this area. I met him for the programme and he summed it up by saying: ‘If you’re well it doesn’t seem like they’ll make you any better.’ But he uses probiotics when there’s a problem.
Some research shows that, in a large enough dose, bacteria can make it through the harsh conditions of your stomach acid to the large intestine where they can live more easily, so it’s plausible they could have a benefit. But, once there, it must compete with thousands of other species in a complex ecosystem. James compares the microbiome (the bacteria living in you) to a vast rainforest.
He says taking a probiotic to make it ‘generally healthier’ is like tinkering with the red squirrel population in Surrey and expecting it to have a beneficial effect on the Peruvian jungle – it’s possible we know more about the Peruvian rainforest than we do about our own insides. We each have thousands of different species in our bowels, and everyone has their own unique ecosystem. The idea there would be one simple drink with one simple bug in it that could make us all feel better is surely a bit ludicrous. What we do know is the fat and sugar found in some probiotic preparations can have negative health effects.
Ironically, this may be because of the effect fat and sugar have on gut bacteria.
Luckily, you don’t need to worry about finding precisely the right dosage and species of bacteria that’s right for you. There’s a much simpler, cheaper treatment: porridge.
‘The fat and sugar found in some probiotic preparations can have negative health effects.’
We’ve long known high-fibre foods, including oats and green leafy vegetables, have many beneficial effects on health. But, even as a doctor, my understanding of why fibre is good for you was incomplete.
I had a vague feeling that roughage worked by cleaning you out, sort of like a brush, and thus got rid of toxins. While this isn’t completely untrue it’s probably more to do with good bacteria in your gut being able to thrive on the indigestible sugars in fibre.
The sugars act as ‘prebiotics’ – a prebiotic is any substance in food which causes a health benefit by affecting gut bacteria (another term the EU are strict about using, as it implies a proven health benefit).
But I wanted to put this to the test, so I went for two weeks with no oats and then six weeks eating more oats than even the man with the caber on the oat packet seems to (a treat for me as I usually have two huge cold lumps of salty porridge per day).
I then sent stool samples to Karen Scott at the Rowett Institute in Aberdeen (the experience gave me new sympathy with patients I ask to send in a stool sample: not easy or dignified to collect . . . again, apologies if you’re reading this over breakfast).
Karen is interested in the effect of diet on the health of gut bacteria and, appropriately for her lab in Scotland, the main food she studies is oats. Karen did a genetic analysis of bacteria in my stool sample each week: as the diet went on the species changed. Some died out, others massively expanded their numbers.
The importance of fibre: Fresh green veg and oats have many beneficial effects on health, especially, as Dr van Tulleken’s experiment showed, because they feed gut bacteria
I felt great, but in larger studies Karen found these changes improve the ecology of the system immensely.
To extend the rainforest analogy: if swigging a yoghurt drink is throwing a few seeds into the forest, significantly altering your diet is like changing the soil and the weather: get it right and the good stuff will flourish.
Once fed, bacteria can perform all their functions and release beneficial compounds into your blood stream. These have wide-ranging effects from the lining of your gut to your heart and bloodstream.
For most of us, it’s the prebiotics in the food we eat which has the major effect on the health of your gut and the bacteria in it.
The reason food may be good or bad for you is because it changes the populations of bacteria and the chemicals they produce.
So while James Kinross and other groups continue to probe the frontiers of your inner universe with the most advanced molecular techniques known to man, I leave you with a conclusion that would have your grandmother saying I told you so: eat more porridge oats.
Christoffer van Tulleken is an infectious diseases doctor at University College London Hospitals, and an MRC research fellow at University College London. Trust Me I’m A Doctor is on BBC2 on Thursday at 8pm. He also presents Operation Ouch every Monday 530pm CBBC.Contact him on Twitter @DoctorChrisVT
Read more: http://www.dailymail.co.uk/health/article-2471095/Forget-trendy-probiotic-drinks–just-eat-porridge.html#ixzz2iWeIUWZj
