Interesting new paper came out recently on “Sex Differences in the Gut Microbiome Drive Hormone-Dependent Regulation of Autoimmunity.” It is alas in Science so it is not available openly.
Anyway there are some news stories about the article where you can get the gist of it. Best one is probably the blog post by Christine Gorman: Transplanted Bacteria Turn Up Testosterone to Protect Mice against Diabetes. The story is pretty interesting.
For those who do not know I have been a bit obsessed about the connection between diabetes and the microbiome for a while. See my Ted talk for example where I discuss my own personal connection to this issue.
http://embed.ted.com/talks/jonathan_eisen_meet_your_microbes.html
But the science is not what I want to talk about here. What I want to talk about is how science press releases can just be awful. The one for this paper is like some sort of con artist’s scheme. Here it is on Science Daily: Good bacteria in the intestine prevent diabetes, study suggests. First, they lure you in with a headline that, well, fails to mention that the study was in mice. And then they keep trying to lure you with some lines about humans and their microbes. In fact, the first two and half paragraphs I think are pretty deceptive.
All humans have enormous numbers of bacteria and other micro-organisms in the lower intestine. In fact our bodies contain about ten times more bacteria than the number of our own cells and these tiny passengers are extremely important for our health. They help us digest our food and provide us with energy and vitamins. These ‘friendly’ commensal bacteria in the intestine help to stop the ‘bad guys’ such as Salmonella that cause infections, taking hold. Even the biochemical reactions that build up and maintain our bodies come from our intestinal bacteria as well as our own cells.
Pretty important that we get along with these little bacterial friends… definitely. But as in all beautiful relationships, things can sometimes turn sour. If the bacteria in the intestine become unbalanced, inflammation and damage can occur at many different locations in the body. The best known of these is the intestine itself: the wrong intestinal bacteria can trigger Crohn’s disease and ulcerative colitis. The liver also becomes damaged when intestinal bacteria are unbalanced.
Research groups led by Professor Jayne Danska at the Sick Children’s Hospital of the University of Toronto and Professor Andrew Macpherson in the Clinic for Visceral Surgery and Medicine at the Inselspital and the University of Bern have now shown that the influence of the intestinal bacteria extends even deeper inside the body to influence the likelihood of getting diabetes. In children and young people, diabetes is caused by the immune cells of the body damaging the special cells in the pancreas that produce the hormone insulin.
Yup – lots and lots of stuff about people. Which is fine. I like people. But the thing is. The paper is about mice. So lines like “have now shown that the influence of the intestinal bacteria extends even deeper inside the body to influence the likelihood of getting diabetes” are kind of misleading because so far there has been no mention of mice and that line is they only true for mice, not people. And then they wrap up this section with another line about people, clearly trying to imply that the “have now shown …” part is relevant to people.
And then, finally, they turn to mice.
By chance, 30 years ago, before the development of genetic engineering techniques, Japanese investigators noticed that a strain of NOD laboratory mice tended to get diabetes. These mice (also by chance) have many of the same genes that make some humans susceptible to the disease. With the help of the special facilities of the University of Bern and in Canada, these teams have been able to show that the intestinal bacteria, especially in male mice, can produce biochemicals and hormones that stop diabetes developing.
And then they go back to people.
Diabetes in young people is becoming more and more frequent, and doctors even talk about a diabetes epidemic. This increase in diabetic disease has happened over the last 40 years as our homes and environment have become cleaner and more hygienic. At the moment, once a child has diabetes, he or she requires life-long treatment.
“We hope that our new understanding of how intestinal bacteria may protect susceptible children from developing diabetes, will allow us to start to develop new treatments to stop children getting the disease,” says Andrew Macpherson of the University Bern.
Wow. So in a press release about a paper that is about mice, there are three sentences about mice and the rest are about people. The thing is, in case you don’t know – mice are not the same as people. Just saying. And for trying to overplay the connection of their work to humans, I am giving the writer’s of this press release my coveted Overselling the Microbiome Award.
Past posts about this award include:
Jonathan Eisen's Lab 