After eight years of research by scientists all over the world, China's discovery explains the connection between intestinal bacteria and obesity. Professor Zhao Liping, a research team from Shanghai Jiaotong University, said: "This is a very important phenomenon. This is the last evidence that bacteria caused obesity before. " Scientists discovered human bacteria related to obesity and fed them to mice, and compared their weight gain with that of mice without bacteria. Although the latter was fed high-fat food and was prevented from exercising, there were no symptoms of obesity.
Other scholars unrelated to the project quickly commented on the potential impact. Professor David Weinkove, a lecturer in biology at Durham University, said: "If obesity is caused by bacteria, it may be contagious, possibly from some unknown environmental factors or from parents. It may not have anything to do with behavior in the end. " Vinkov believes that Professor Zhao's research has paved the way for interventional therapy of obesity, and it is possible to develop therapeutic drugs. Researchers from Toronto Sick Children's Hospital found that exposure to gastrointestinal bacteria early in life can help mice prevent autoimmune diseases. This study also reveals the reasons why women are at higher risk of autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and lupus erythematosus than men. Related papers were published in the journal Science in June 5438+10/October 65438+July.
This study is the first time to clarify the difference of normal intestinal microorganisms between male and female mice raised in the same environment, and confirmed that transferring male intestinal bacteria into female mice with high genetic risk can prevent autoimmune diseases.
The second unexpected discovery is to reveal the influence of intestinal microbial therapy on sex hormones. When young female mice are exposed to normal intestinal microorganisms of adult male mice, their testosterone levels will increase. Later, scientists confirmed that this hormone is very important for intestinal microbial treatment to prevent this disease. It is found that the sex of animals determines the composition of intestinal microorganisms, which affect the level of sex hormones and then regulate an immune-mediated disease. American and French researchers found in February 20 13 that intestinal flora can also control the human body's response to cancer treatment drugs.
Researchers from the French Pasteur Institute and other institutions reported in the American journal Science that cyclophosphamide, a commonly used drug in cancer chemotherapy, can destroy the intestinal mucus layer and let intestinal bacteria enter the circulatory system. Some bacteria that reach the spleen and lymph nodes can promote the formation of immune cells, which will attack cancer cells. However, the ability of cyclophosphamide to indirectly promote immune cells will be greatly reduced when researchers kill intestinal bacteria in experimental mice with antibiotics.
Another study published by the National Cancer Institute of the United States in the same period of Science magazine showed that the researchers chose cancer experimental mice with a survival rate of 70% and killed their intestinal bacteria with antibiotics. As a result, the chemotherapy drugs ingested by these experimental mice no longer worked, and the survival rate dropped to 20% after two months.
The researchers tested oxaliplatin, a drug used to treat colon cancer. This drug works best when the intestinal bacteria of the subjects are in an ideal state. But when antibiotics are used to kill intestinal bacteria, the efficacy of oxaliplatin is greatly reduced.
Generally speaking, doctors often need to use a lot of antibiotics for cancer patients to prevent infection, but studies have found that antibiotics may affect the efficacy of anticancer drugs. These two studies also show that different kinds of intestinal bacteria contribute to different anticancer drugs. Previous studies have found that some kinds of intestinal bacteria may also promote the occurrence of intestinal cancer, and intestinal bacteria should not be blindly supplemented.