When it comes to obesity, many people's first reactions are "heredity", "unreasonable diet" and "lack of exercise". It is true that familial obesity, high-sugar and high-fat diet and lack of exercise are the main causes of obesity, but some recent studies have shown that some bacteria lurking in the human intestine play a vital role in the production of obesity.

This research comes from Professor Zhao Liping of Shanghai Jiaotong University, who published an article in ISME Daily, reporting a bacterium that may be directly related to obesity.

In 2006, Professor Jeffrey Gordon of the University of Washington in the United States showed through experiments that mice with normal flora ate less than mice without bacteria in their intestines, but accumulated more fat. However, after the intestinal flora of normal mice was introduced into the intestines of sterile mice, the sterile mice that were originally "not fat after eating too much" became "fat after drinking water" uncharacteristically. This result shows that intestinal flora can really affect the body's ability intake and metabolic level. It has become an urgent problem that which members of intestinal flora cause the metabolic changes in mice.

In order to solve this problem, Zhao Liping found an obese patient with a weight of 175 kg and a body mass index as high as 58.78 (the standard body mass index of normal men is generally 24[3]), and gave him diet intervention and drug treatment to reduce his weight. Regularly detect the composition of intestinal flora while losing weight.

"Obese bacteria" Enterobacter cloacae

After 23 weeks' intervention, the patient lost nearly 52 kilograms, and the symptoms of hyperinsulinemia, hyperglycemia, hypertension with obesity were also obviously improved. At the same time, the detection of intestinal flora of patients showed that Enterobacter cloacae, which initially accounted for 30% of the total flora, was almost undetectable in the intestinal flora after intervention treatment. This remarkable change makes people realize that Enterobacter cloacae is likely to have an important connection with this patient's obesity.

Therefore, Zhao Liping and other members of the research group isolated Enterobacter cloacae from patients' intestines and introduced it into the intestines of sterile mice. Then these mice were divided into two groups: one group was fed with ordinary feed, the other group was fed with high-fat and high-sugar feed, and sterile mice were used as control. The results showed that mice fed with Enterobacter cloacae and high-fat and high-sugar diet gained weight rapidly, accumulated more fat in various organs, and developed obesity-related symptoms such as insulin resistance. These phenomena indicate that Enterobacter cloacae may be the cause of obesity and other metabolic abnormalities in mice.

In order to further explore how Enterobacter cloacae makes mice obese, Zhao Liping and members of the research group analyzed the plasma components of mice. The results showed that the protein content of lipopolysaccharide endotoxin which can bind to bacteria secretion in the serum of mice fed with Enterobacter cloacae and fed with high fat and high sugar was significantly higher than that of the other three groups, indicating that the mice in this group ingested more endotoxin. At the same time, the serum amyloid level of the mice in this group increased significantly, and the adiponectin level decreased significantly. These two indicators show that the metabolism of this group of mice is indeed abnormal and in an inflammatory state.

Enterobacter cloacae is the only bacterium that produces lipopolysaccharide endotoxin in the intestines of this group of mice. Lipopolysaccharide endotoxin can cause inflammatory reaction in the body, and then lead to metabolic problems by changing the expression of metabolism-related genes. It can be seen that Enterobacter cloacae is the direct cause of metabolic problems in mice. Similarly, the metabolic problem of the obese patient treated by Professor Zhao is largely due to the abnormal increase of Enterobacter cloacae in the intestine.

Reasonable diet+exercise is king

However, although Enterobacter cloacae is an important factor leading to obesity, if we find a solution to obesity as advertised by some media, it is to catch sesame seeds and lose watermelon. Because the Enterobacter cloacae discovered by people is actually just one of the "accomplices", and the real "mastermind" is the self who lacks exercise and unreasonable diet.

Therefore, friends who want to lose weight, as well as MM who are in normal health and just want to be slimmer, should not pin their hopes entirely on "sterilization and weight loss", but should eat reasonably and exercise more.