The Bacteria Dot

Intestinal DistressedFor the title’s context, please see yesterday’s post, “The Microbiome—More Dots to Connect.”

Colonies of bacteria live inside us and carry out their agendas. The first big question is how they impact obesity. The second biggest question is how obesity impacts them. There are a thousand more questions. If the bugs don’t like it when we are fat, what do they do about it? If they do like us to be fat, how do they encourage it? What if we have some of each kind, and they are slugging it out, inside of us, in an apocalyptic battle for possession of the host body?

Can we get better bugs? If we can, will that help, or will we overcome their good intentions by the sheer power of our bad habits? Some of the people interested in these questions are in the Molecular Epidemiology of Chronic Diseases field at Maastricht University. Here is brand-new news, published in the journal Obesity, from the Netherlands (which is the “second largest exporter of agro & food products next to the USA”):

Methanobrevibacter smithii, or M. smithii, is an ancient bacteria that is commonly found in the gastrointestinal tract. The presence of this bacteria has recently been linked to obesity…They found that the bacteria was present to some degree in eighty percent of the children, with twenty percent showing no signs of the bacteria at all.

That alone raises a question. Living in the same part of the world, in the same age group, doing pretty much the same things, it seems that people would have the same bacteria, even if only a little bit of it. But this source says “no signs of the bacteria at all” in part of the population. How can that be, and what does it mean?

The single-celled M. smithii belongs to the ancient family called archaea, and the press release says they “usually tend to occur under extreme circumstances, such as heat, cold or high pressure.” It seems that we must either re-define the word “usually” to include a normal human gastrointestinal tract, or admit that life inside a human is extreme.

The subjects in this study were 500 children, ages six to ten, who were weighed and measured for several years. The kids who had higher concentrations of M. smithii were more likely to be obese. The presence of large numbers of this bacteria in the microbiome could as much as triple the risk. The researchers have no idea why; they know only that, like other species of gut bacteria, M. smithii help to break down dietary fibers that our bodies alone can’t handle. They do a needed job, but apparently contribute to obesity in some yet-to-be-discovered way. Prof. Ilja Arts says:

We suspect that obesity is more than just the result of eating too much and exercising too little. Other factors, such as microorganisms in the gastrointestinal tract, likely play a role as well. They may also contribute to obesity-related complications.

Of course, the first question the general public will ask is, “How do we get rid of these fattening M. smithii? We don’t want them. We don’t want to be fat.” Even though the scientists admit that they don’t know much about the gut microbiome, one thing they begin to suspect is that blindly messing around with it, unarmed with reliable knowledge, can be detrimental.

In the interests of full disclosure, we learn that this research is part of the KOALA study, under the aegis of Maastricht University and several partnering research institutes. KOALA is a birth cohort study that focuses on lifestyle and genetic constitution. Within that, there is a more general interest in growth and development, and a specific interest in allergies and asthma.

The M. smithii study was sponsored by TI Food and Nutrition, which promotes “an integrated approach in which science and industry, supported by government, share their knowledge and expertise.” TI Food and Nutrition does “precompetitive strategic research” and its website shows 27 corporate logos.

Your responses and feedback are welcome!

Source: “Ancient gut bacteria linked to childhood obesity,”, 12/01/15
Source: “A collective effort,”, undated
Image by Orin Zebest

Leave a Reply

Your email address will not be published. Required fields are marked *

FAQs and Media Requests: Click here…

Profiles: Kids Struggling with Weight

Profiles: Kids Struggling with Obesity top bottom

The Book

OVERWEIGHT: What Kids Say explores the obesity problem from the often-overlooked perspective of children struggling with being overweight.

About Dr. Robert A. Pretlow

Dr. Robert A. Pretlow is a pediatrician and childhood obesity specialist. He has been researching and spreading awareness on the childhood obesity epidemic in the US for more than a decade.
You can contact Dr. Pretlow at:


Dr. Pretlow’s invited presentation at the American Society of Animal Science 2020 Conference
What’s Causing Obesity in Companion Animals and What Can We Do About It

Dr. Pretlow’s invited presentation at the World Obesity Federation 2019 Conference:
Food/Eating Addiction and the Displacement Mechanism

Dr. Pretlow’s Multi-Center Clinical Trial Kick-off Speech 2018:
Obesity: Tackling the Root Cause

Dr. Pretlow’s 2017 Workshop on
Treatment of Obesity Using the Addiction Model

Dr. Pretlow’s invited presentation for
TEC and UNC 2016

Dr. Pretlow’s invited presentation at the 2015 Obesity Summit in London, UK.

Dr. Pretlow’s invited keynote at the 2014 European Childhood Obesity Group Congress in Salzburg, Austria.

Dr. Pretlow’s presentation at the 2013 European Congress on Obesity in Liverpool, UK.

Dr. Pretlow’s presentation at the 2011 International Conference on Childhood Obesity in Lisbon, Portugal.

Dr. Pretlow’s presentation at the 2010 Uniting Against Childhood Obesity Conference in Houston, TX.

Food & Health Resources