From the New Scientist, 5/4/2017 (excerpt)
How we can make friends with harmful bacteria - Drew Smith.
Antibiotics are among the safest drugs. Indeed, doctors even prescribe them for viral infections, knowing they are useless, on the grounds that “it can’t hurt”.
Except that it can. And not just because it leads bacteria to develop resistance to the drugs. Antibiotic-associated diarrhoea and allergic reactions commonly send people to hospital. And antibiotic use is almost always the cause of diarrhoea associated with Clostridium difficile, which kills nearly 30,000 Americans every year.
But people who study the microbiome suggest the toll may be far higher. One study in Denmark, for example, revealed that people who redeemed five or more antibiotic prescriptions over the course of a 15-year period were much more likely to develop type 2 diabetes compared with those who took antibiotics once or less during this time.
Beyond diabetes, changes in the balance of bacteria in our guts are now associated with obesity, inflammatory and autoimmune disorders and even depression. Antibiotic use, especially in childhood, has been found to be a risk factor for all of these.
In some sense, links to obesity shouldn’t be news. Antibiotics have been used to fatten livestock since the 1940s. The first study showing a similar effect in people dates to 1955. But the mechanism was a mystery and there was little interest in follow-up. Germs were our enemy, antibiotics got rid of germs, so antibiotics were good, right?
Until the last decade, few imagined that gut bacteria might be needed for the development of our immune, metabolic and nervous systems. But it’s becoming clearer as links between the use of antibiotics and an increased risk of diabetes, psychosis, anxiety, depression and obesity steadily grow.
There is a lot that we still don’t know about the balance of bacteria in our bodies, but we now know enough to understand that constantly disrupting it is imprudent, even dangerous. Even if the rise of antibiotic resistance did not drive a need for alternative therapies, the need to preserve our health does.
1 in 3 - Number of unnecessary prescriptions for antibiotics
25,000 - People in the European Union who die from antibiotic resistant infections each year
99 per cent - The proportion of bacteria in or on our bodies that do us no harm