Posted on Obesity

Some guts are better than others at harvesting energy

Associate professor Henrik Roager


Associate professor Henrik Roager in the lab. CREDIT University of Copenhagen.

New research from the University of Copenhagen suggests that a portion of the Danish population has a composition of gut microbes that, on average, extracts more energy from food than do the microbes in the guts of their fellow Danes. The research is a step towards understanding why some people gain more weight than others, even when they eat the same.

Unfair as it, some of us seem to put on weight just by looking at a plate of Christmas cookies, while others can munch away with abandon and not gain a gram. Part of the explanation could be related to the composition of our gut microbes. This, according to new research conducted at the University of Copenhagen’s Department of Nutrition, Exercise and Sports.

Researchers studied the residual energy in the faeces of 85 Danes to estimate how effective their gut microbes are at extracting energy from food. At the same time, they mapped the composition of gut microbes for each participant.

The results show that roughly 40 percent of the participants belong to a group that, on average, extracts more energy from food compared to the other 60 percent. The researchers also observed that those who extracted the most energy from food also weighed 10 percent more on average, amounting to an extra nine kilograms.

“We may have found a key to understanding why some people gain more weight than others, even when they don’t eat more or any differently. But this needs to be investigated further,” says Associate Professor Henrik Roager of the University of Copenhagen’s Department of Nutrition, Exercise and Sports.

May increase the risk of obesity

The results indicate that being overweight might not just be related to how healthily one eats or the amount of exercise one gets. It may also have something to do with the composition of a person’s gut microbes. 

Participants were divided into three groups, based on the composition of their gut microbes. The so-called B-type composition (dominated by Bacteroides bacteria) is more effective at extracting nutrients from food and was observed in 40 percent of the participants.

Following the study, the researchers suspect that a portion of the population may be disadvantaged by having gut bacteria that are a bit too effective at extracting energy. This effectiveness may result in more calories being available for the human host from the same amount of food.

“The fact that our gut bacteria are great at extracting energy from food is basically a good thing, as the bacteria’s metabolism of food provides extra energy in the form of, for example, short-chain fatty acids , which are molecules that our body can use as energy-supplying fuel. But if we consume more than we burn, the extra energy provided by the intestinal bacteria may increase the risk of obesity over time,” says Henrik Roager.

Short travel time in the gut surprises

From mouth to esophagus, stomach, duodenum and small intestine, large intestine and finally to rectum, the food we eat takes a 12-to-36-hour journey, passing several stations along the way, before the body has extracted all the food’s nutrients.

The researchers also studied the length of this journey for each participant, all of whom had similar dietary patterns. Here, the researchers hypothesized that those with long digestive travel times would be the ones who harvested the most nutrition from their food. But the study found the exact opposite.

“We thought that there would be a long digestive travel time would allow more energy to be extracted. But here, we see that participants with the B-type gut bacteria that extract the most energy, also have the fastest passage through the gastrointestinal system, which has given us something to think about,” says Henrik Roager.

Confirms previous study in mice

The new study in humans confirms earlier studies in mice. In these studies, it was found that germ-free mice that received gut microbes from obese donors gained more weight compared to mice that received gut microbes from lean donors, despite being fed the same diet.

Even then, the researchers proposed that the differences in weight gain could be attributable to the fact that the gut bacteria from obese people were more efficient at extracting energy from food. This is the theory now being confirmed in the new study by the Department of Nutrition, Exercise and Sports.

“It is very interesting that the group of people who have less energy left in their stool also weigh more on average. However, this study doesn’t provide proof that the two factors are directly related. We hope to explore this more in the future,” says Henrik Roager. 

About gut bacteria:

  • Everyone has a unique composition of gut bacteria – shaped by genetics, environment, lifestyle and diet.
  • The collection of gut bacteria, called the gut microbiota, is like an entire galaxy in our gut, with a staggering 100 billion of them per gram of stool.
  • Gut bacteria in the colon serve to break down food parts that our body’s digestive enzymes can’t, e.g., dietary fibre.
  • Humans can be divided into three groups based on the presence and abundance of three main groups of bacteria that most of us have: B-type (Bacteroides), R-type (Ruminococcaceae) and P-type (Prevotella).
Posted on Rheumatoid arthritis

Treating Rheumatoid Arthritis with a Whole Food, Plant-Based diet in 21 days

Healthy eating as a vegan
Healthy eating as a vegan


With the GreenFare 21 Day Kickstart program, an easy path to reversing most chronic illnesses is provided: show up for class and eat the food!

Posted on Autism

Autism: An evolutionary perspective, Professor Simon Baron-Cohen, 1st Symposium of EPSIG, 2016

Autism: An evolutionary perspective, Professor Simon Baron-Cohen, 1st Symposium of EPSIG, 2016 - YouTube


First Symposium of the Evolutionary Psychiatry Special Interest Group of the Royal College of Psychiatrists, Oct 4th 2016 in London. Lecture by Professor Simon Baron-Cohen from Cambridge University Autism Research Centre.

Posted on Autism

This model explains how autism many arise. Interesting, but I’m not convinced. What about you?

Pyramid model illustration


The three factors have different weights, and jointly build up to the diagnosis of autism. CREDIT University of Gothenburg

The development of autism may now become easier to understand, thanks to an explanatory model presented in a thesis from University of Gothenburg, Sweden. This model provides new insights into how various risk factors give rise to autism and why there is such great variability between individuals.

Autism, a neurodevelopmental condition, affects how people perceive the world around them and how they interact and communicate with others. Among individuals with autism, there are major differences in terms of personal traits and manifestations alike. The disorder is therefore usually described as a spectrum, with numerous subtle variations.

The new explanatory model is theoretical but simultaneously practical in application, since its various components are measurable through, for example, questionnaires, genetic mapping, and psychological tests. The model describes various contributing factors and how they combine to prompt an autism diagnosis and cause other neurodevelopmental conditions.

Three contributing factors

The model links three contributing factors. Together, these result in a pattern of behavior that meets the criteria for an autism diagnosis:

1. Autistic personality — hereditary common genetic variants that give rise to an autistic personality.

2. Cognitive compensation — intelligence and executive functions, such as the capacity to learn, understand others, and adapt to social interactions.

1. Exposure to risk factors — for example, harmful genetic variants, infections, and other random events during gestation and early childhood that adversely affect cognitive ability.

“The autistic personality is associated with both strengths and difficulties in cognition but does not, as such, mean that diagnostic criteria are fulfilled. Still, exposure to risk factors that inhibit people’s cognitive ability may affect their capacity to tackle difficulties, which contributes to individuals being diagnosed with autism,” says Darko Sarovic, physician and postdoctoral researcher at Sahlgrenska Academy, University of Gothenburg, who wrote the thesis.

The model makes it clear that it is the many different risk factors combined that bring about the major differences among individuals on the spectrum. The various components of the model are supported by results from previous research.

Adaptive ability

High executive functioning skills may enable people to compensate for their impairment in such a way as to mitigate the symptoms, which reduces their risk of meeting the diagnostic criteria for autism. This may explain why, at group level, researchers observe a lower degree of intelligence among people diagnosed with autism, as well as other neurodevelopmental conditions. It also affords an understanding of why intellectual disability is more common among these groups. Thus, the model indicates that low cognitive ability is not part of the autistic personality but, rather, a risk factor that leads to diagnostic criteria being met.

“The autistic personality is associated with various strengths. For example, parents of children with autism are overrepresented among engineers and mathematicians. The parents themselves have probably been able to compensate for their own autistic personality traits and thus not met the criteria for an autism diagnosis. The impact of the disorder has then become more noticeable in their children owing, for instance, to an exposure to risk factors and relatively low cognitive ability,” Sarovic says.

Difference between girls and boys

The diagnosis of autism is more common among boys than girls, and girls often get their diagnosis later in life. Some girls reach adulthood before being diagnosed, after many years of diffuse personal difficulties.

“Girls’ symptoms are often less evident to other people. It’s well known that girls generally have more advanced social skills, which probably means that they’re better at compensating for their own difficulties. Girls also tend to have fewer autistic traits and be less susceptible to the effects of risk factors. Accordingly, the model can help to answer questions about the gender gap,” Sarovic says.

Research and diagnostics

The model also proposes ways of estimating and measuring the three factors (autistic personality, cognitive compensation and exposure to risk factors). This makes it possible to use the model in the planning of research studies and interpretation of their results.

Diagnostics is another conceivable area of ​​use. In a pilot study in which 24 participants had been diagnosed with autism and 22 controls had not, measuring the three factors of the model enabled more than 93 percent to be correctly assigned to the right category. The model can also be used to explain the inception of other neurodevelopmental disorders, such as schizophrenia.