Portrait with dummy

There is so much research out there and so many claims of what cures and causes so many diseases that most of us just switch off. As I have written previously it has actually been shown that for most foods there are a roughly equal number of studies showing an increase and a decrease in rates of cancer.

So what filters can be used to start to determine what might be useful information? One is the common sense test. Knowledge which just makes sense has a better than even chance of doing just that. The other is a repeated theme in different areas.

This does not prove something is right as wrong information can feed on itself.

The blog post retraction watch keeps track of research papers, which are “retracted” or withdrawn. It is staggering how often these papers, which are found to be false, are cited in other works.

What has struck me as a useful guide over the last few years is when the same theme bobs up in unrelated areas.

And so it was that a paper looking at parents who cleaned their baby’s dummy (pacifier) by sucking it clean had children with lower rates of allergies. By itself this study proves little. There may be a number of other factors affecting the development of allergic problems in children. But hyper sterile environments and lack of exposure to bacteria and dirt keeps coming up in more and more studies.

Children from rural areas have lower allergy conditions (hay fever, asthma and eczema) rates compared to those in cities. Those in developing countries have lower rates than those in the first world. Children given courses of antibiotics in their first six months of life have higher rates. The dummy paper mentioned above showed that the children in the “suck it clean” group had bacteria in their mouths similar to their parents.

The notion of 99% germ free is nonsense. There are 10 times more bacterial cells in the human intestine than there are human cells in our entire body! And we know from other work that when these bacteria get disturbed that problems arise. The most obvious is antibiotic associated diarrhoea, which kills over 20,000 Americans each year. It comes about when antibiotics kill off good bacteria in the gut. Courses of probiotics have been shown to help ward off serious gut infections in premature babies.

We also know that the absorption of foods is affected by gut bacteria. Indeed some vitamins cannot be absorbed without them.

New work is suggesting that the link between red meat consumption and heart disease has nothing to do with cholesterol but is mediated by other inflammatory compounds, which in turn are influenced by gut bacteria.

Last year the Economist newspaper ran a cover story, which referred to the Human Ecosystem in place of the Human Body. When you consider the numbers of bacteria we host this is not a bad description.

So what is the take home message? There are some “bad “ bacteria but the vast majority are good and we need them arguably more than they need us. We need to be very judicious in our use of antibiotics and NOT use them in viral illnesses such as colds and influenza. This applies to children and adults. The notion of a course of antibiotic having no downside is false.

Let your children play in the dirt. Do not be paranoid about “germs”. You cannot get rid of them regardless of how hard you try. Consider having a course of probiotics from time to time.

Our ideas about bacteria are in the main wrong. They are far more our allies than the enemy.