Overselling the microbiome award: Time Magazine & Martin Blaser for "antibiotics are extinguishing our microbiome"

Well, alas, Time magazine turned what could have been a story about the spread of antibiotic resistance into what appears to be a promotion for Martin Blaser’s new book: Antibiotic-Resistant Bacteria Are Now In Every Part of the World | TIME.com.

The article starts of OK – reporting on the new WHO report on antibiotic resistance.  But then it gets into the microbiome and what antibiotics supposedly do to it.  Some quotes:

“But even more concerning, say experts like Dr. Martin Blaser, director of the human microbiome program at the New York University Langone Medical Center and author of Missing Microbes, is how these antibiotics are affecting the makeup of both good and bad bacteria that live within us – our microbiome. The first big cost of antibiotics is resistance,” he says. “But the other side of the coin is [the fact that] antibiotics are extinguishing our microbiome and changing human development.

Extinguishing our microbiome?  Really?  The evidence simply does not support such a claim.  I personally think antibiotics may be contributing to messing up the microbiome in many people and that this in turn might be contributing to the increase in a variety of human ailments (e.g., I mentioned this issue in my TED talk and many many times here and elsewhere).  But “extinguishing”?  Not even close.  In fact, many of the published sutdies done so far suggest that the human microbiome is pretty resilient in response to antibiotics.  Really serious overselling of the impact of antiobitcs by Blaser.

And “changing human development?”  Not sure what the evidence for that is either.  Most likely this refers to the role the microbiome plays in immune system development but I am not aware of strong evidence that antibiotics lead to changes in human devleopment.

They then quote Blaser again:

If I prescribe a heart medicine for a patient, that heart medicine is going to affect that patient,” says Blaser. “But if I prescribe an antibiotic, that antibiotic will affect the entire community to some degree. And the effect is cumulative.

Yes antibiotics can affect more than one person because microbes (and resistance) can spread.  But “the effect is cumulative”?  I do not think that has been shown.

Finally, Time (well, Alice Park, the author) states (in relation to limiting overuse of antibiotics)

That may also help to protect our microbiomes, which in turn could slow the appearance of chronic diseases such as obesity, cancer and allergies.

What?  Now antibiotics cause obesity?  And allergies?  And cancer? Sure – there is good reason to think that antibiotic usage plays a role in obesity and allergies.  The evidence is not yet completely overwhelming but it is certainly a reasonable notion.  But how did cancer get thrown in here?

I note – as I assume many know – I think the microbiome is critical to many human functions and phenotypes.  And screwing with it via excessive use of antibiotics seems like a very very bad idea.  The precautionary principle says to me we should avoid any antimicrobials unless absolutely necessary.  But do we really need to overstate what we know in order to effect change?  Do we need to say things like “antibiotics are extinguishing our microbiome” which is simply untrue?  I don’t think we do.  I think we can be more careful, not mislead people, and still have an impact.  And thus, I am giving out today’s “Overselling the microbiome” award to Time magazine and Martin Blaser.

UPDATE 5/1 – some links of interest

Other Overselling the Microbome Awards:

Some papers of relevance on antibioics and the microbiome

Ancestral human microbiome

UPDATE 5/3/4

Some papers that offer a more tempered view of the role of the microbiome in causing various disease:

  • Disturbed gut colonisation patterns have been associated with allergic disease, but whether microbial variation is the cause or effect of these diseases is still under investigation. We are far from understanding what constitutes a “healthy gut microbiome” that promotes tolerance. This remains a major limitation and might explain some of the inconsistency in human intervention studies with prebiotics and probiotics. Multidisciplinary integrative approaches with researchers working in networks, using harmonised outcomes and methodologies are needed to advance our understanding in this field.
  • Such data suggest that bona fide associations may exist between microbiota and obesity in humans, although causality remains to be addressed. Whether these associations will hold up to large-scale replication has yet to be determined. This situation is reminiscent of genetic association studies done in the pre-genome-wide association scan era, during which many candidate associations were found using sample sizes which at the time were considered large, but were rather small in retrospect [54]. Very few of these earlier associations have held up to replication in the modern era, where the threshold for association is more stringent and requires sample sizes orders of magnitude larger [55]. It seems reasonable to postulate that causal contributions from the gut microbiome to the development of human obesity have effect sizes on the order of common genetic variations implicated in complex diseases. If this is the case, much larger studies will be necessary before we have clear evidence of association.  
  • This review considers the nature of the evidence supporting a relationship between the microbiota and the predisposition to disease as associative, correlative, or causal. Altogether, indirect or associative support currently dominates the evidence base, which now suggests that the intestinal microbiome can be linked to a growing number of over 25 diseases or syndromes. While only a handful of cause-and-effect studies have been performed, this form of evidence is increasing. 
  • Talk by Rob Knight on “From Correlation to Causation in Human Microbiome Studies”

Update 5/4 #2.  I would also recommend people check out the Helicobacter foundation web site. which has some useful background information on the organism and the diseases it causes.

Update 5/4 #3.  Some recent papers by Martin Blaser worth looking at

UPDATE 5/4/#4. Martin Blaser on Dr. Oz show where Dr. Oz and Blaser both make some statements that are a seriously over the top.

History of studies of the affect of antibiotics on human health

Oh – and Barry Marshall – winner of the Nobel Prize for discovering how H. pylori causes ulcers and cancer – chimed in on Twitter:

//platform.twitter.com/widgets.js Other Tweets of relevance






UPDATE 5/4 – Caesarian Section Risk notes

A related question I have been thinking about involves Caesarian sections and whether they lead to an increased risk of any ailments that might have a microbial connection (e.g., obesity, allergy, autoimmune diseases). I started digging into the literature on this for my TED talk and then again when I posted something from the Smithsonian Genomics Exhibit that suggested there were no risks associated with C-sections.

Some papers on the topic suggest there may be some risks from C-sections related to these topics but that they are very very small:

UPDATE 5/5 Diabetes

Increase in type 1 and type 2 diabetes rates in children reported – is this connected to antibiotic usage or microbiomes?

Microbes and obesity – more connections

A couple of recent papers on weight-loss surgery and microbes have gotten a lot of attention to the idea that obesity and microbes have a more than just coincidental connection.

Some of the news stories on the topic are below. A few of them are a bit over the top but the new work seems pretty sound so this is definitely worth a look.

I can’t keep up so here are some unfiltered links on obesity and microbiomes

I just can’t keep up.  These seem like they might be worth reading.  But no time to blog about them.  So here are some possible things to look at if you care about obesity and its possible connection to the microbiome.


News stories:

And I am sure there is a lot more ….

Overselling the microbiome award: MedicalDaily on Effects of Sugary Drink

There is a news article of possible interest in Medical Daily: Sugary Drinks Increase Bad Bacteria in Gut, Risk of Diabetes : Consumer News  This article reports on a paper in Obesity Reviews.  Alas the paper is not freely available. But the PhD thesis from one of the authors is.  The thesis is fascinating – I have read much of it now and skimmed other parts and it has the article as Chapter 2.  There are a few differences in the abstract – for example the Obesity Reviews paper does not start off with “The saying “you are what you eat” is no longer pure folklore but is scientifically substantiated by recognition of host-microbe interactions promoting digestion, absorption and metabolism.” which is in the thesis chapter.  But my guess is the published article is very similar to the thesis chapter.

The news article really goes overboard in hyping what appears to be little more than a correlation.  Among the issues I have:

  • Title:  Sugary Drinks Increase Bad Bacteria in Gut, Risk of Diabetes
    • Whew.  It is a doozy.  No evidence that the bacteria found are “bad” as far as I can tell.  No evidence that sugary drinks specifically cause the increase.  The paper is a review paper outlining a lot of prior work and some theories hypothesizing connections between fructose and sweeteners and the microbiome and obesity.  But I don’t see any evidence of specific increases in bad bacteria in the gut.
  • Byline: Sugary drinks help bad microbes grow in the human gut. This increase leads to many health complications like obesity and metabolic syndrome, raising risk of diseases associated with metabolic syndrome like diabetes.
    • Wow.  Even worse than the title.  Sugary drinks help the bad microbes grow.  And this leads to many health complications.  No evidence is presented for this.

In this case it is certainly much better to go to the source than to read the news story since the source (the PhD thesis and presumably the review paper) is quite thorough and interesting.  It has some fascinating ideas about sugar and sugar substitutes and their potential effects.

Mind you, I think microbes play a role in obesity too.  But the simple “sugary drinks CAUSE growth of bad bacteria which CAUSES health problems” well, if only it were so.  So for their overselling the effects of sugar and the microbiome without evidence I am giving the Medical Daily a highly coveted “overselling the microbiome award“.