Eating sugar without gaining weight and having six-pack abs? This is what I dream of...

There is a joke that has been widely circulated in the scientific research community: "The mechanism is hard to find, the intestinal flora."

As research on human health becomes increasingly popular, almost all human diseases, including diabetes, various neurological diseases, and even psychological diseases such as depression, have been found to be closely related to intestinal microorganisms.

Some time ago, an article published in the journal Gastroenterology by researchers from the University of Copenhagen suggested that the reason why some Inuit (also known as Eskimos) can eat sugar without gaining weight is actually related to intestinal flora. What's going on?

"Eating sugar without getting fat" and "Eating sugar without feeling sick"

I guess everyone has fantasized about being able to enjoy all kinds of delicious candies and desserts, plus a cup of sweet milk tea, without having to worry about gaining weight or other problems.

This recent scientific report found that some Inuit people actually have this imaginary physical state, where they can take in large amounts of sugar without it being converted into fat and causing weight gain.

Image source: pexels

Behind this enviable physical condition, there is another problem, which is also the real reason why scientists started this study. That is, scientists found that some children in Greenland will have severe gastrointestinal symptoms when they consume sugar. Just like many people in daily life are lactose intolerant, but the types of sugar they are intolerant to are far more than just lactose.

Studies have shown that the source of the phenomenon of "eating sugar without getting fat" in adults and "discomfort eating sugar" in children both point to a substance called "sucrase-isomaltase".

It turns out that the frequency of loss-of-function variants of the sucrase-isomaltase gene has increased significantly among people living in Greenland. This genetic defect causes congenital sucrase-isomaltase deficiency in people.

The role of sucrase-isomaltase

Sucrase-isomaltase deficiency causes the body to be unable to break down and absorb sucrose and isomaltose normally. After consuming sugar, most people absorb it into the blood, which is then oxidized or glycolyzed and converted into glycogen or fat. After the body's energy supply is met, the excess energy will be converted into fat and stored, and weight will increase accordingly.

In people with this gene mutation, sugar cannot be broken down by sucrase-isomaltose. Although the human body cannot break it down, the intestinal flora in the body comes to the rescue. These unbreakable sugars will directly enter the intestines, where the intestinal flora will convert them into a short-chain fatty acid, acetate.

However, the intestinal flora in children is different from that in adults and cannot convert these sugars. The gastrointestinal tract that cannot process these sugars naturally "strikes", causing gastrointestinal diseases such as diarrhea, abdominal pain and bloating in children.

Acetate, which is converted by intestinal bacteria in adults, has been shown to reduce appetite, increase metabolism and enhance the immune system. This has given these Inuit people a lower body mass index (BMI), triglyceride content, cholesterol level, and more acetate. At the same time, this also makes them less fat in the abdomen, which may make it easier to get six-pack abs.

The gene-defective samples (HO) had significantly lower BMI, triglycerides, and cholesterol levels, and produced higher levels of acetate. , Source: Gastroenterology

Why did the Inuit become the "chosen ones"?

It is estimated that about 2%-3% of the Inuit carry this gene mutation, while this gene mutation is rarely found in people in other parts of the world. Why did God choose the Inuit to be able to "not gain weight"?

Scientists speculate that this relatively wide genetic variation may be due to their unique dietary habits over thousands of years.

Greenland is close to the North Pole and is extremely cold all year round. Therefore, the Inuit have very limited food choices, usually various fish, seals, reindeer, etc., and the cooking methods are relatively simple. These foods are extremely low in sugar, and their bodies hardly need to absorb sugar quickly from the blood.

Through thousands of years of this eating habit, the human body has been shaped, allowing the sucrase-isomaltase gene mutation to be inherited and expanded. The habit of not eating sugar for thousands of years has made it possible to eat sugar casually today.

Certification of scientific experiments

To verify this hypothesis, the research team then conducted an animal experiment on mice. They knocked out the sucrase-isomaltase gene in mice, making it impossible for the mice with the knocked-out gene to produce sucrase-isomaltase normally.

The results were as expected by the scientists. Compared with normal mice, the glucose level in their blood was lower, the acetate level was higher, and the weight gain was lower. After oral administration of sucrose, the levels of short-chain fatty acids, especially acetate, in the blood of mice whose sucrase-isomaltase gene was knocked out increased significantly, which also provided strong support for this hypothesis.

Mice with knockout sucrase-isomaltase gene (red line) have significantly higher acetate levels in their blood and relatively lower glucose levels in their blood. Source: Gastroenterology

The research team hopes that this research can lay the foundation for the development of new drugs for cardiovascular disease and obesity.

Just imagine, if we could obtain the ability to weaken sucrase-isomaltase through drugs, it might help more people avoid the health problems caused by excessive sugar intake, and you could also have six-pack abs more easily!

But in order to avoid becoming an Inuit child with diarrhea, you also need to have intestinal flora that can convert sugar.

The development of drugs related to intestinal flora faces very complex problems. Each person's intestinal flora varies greatly. Individual differences will lead to different individual responses to dietary fiber intervention. In addition, long-term evolution has made our organs, especially the brain, heavily dependent on blood sugar for energy. There is no solution to the current situation. At this stage, if you want to have six-pack abs, you still have to rely on yourself to exercise more and eat healthily.

END

This article was reviewed by Wang Guoyi, a postdoctoral fellow in food safety

Editor/Heart and Paper