The "entanglement" between intestinal microorganisms and type 2 diabetes

Intestinal microflora is the largest micro ecosystem of human body. The results showed that there was a certain correlation between intestinal microorganisms and the occurrence, development and prognosis of type 2 diabetes.

Intestinal microflora is the largest micro ecosystem of human body. The results showed that there was a certain correlation between intestinal microorganisms and the occurrence, development and prognosis of type 2 diabetes.

Huge intestinal microecology

The intestine is the body’s largest immune organ and a diverse microbial ecosystem. The human body contains 10 to 100 trillion microbiota, which is more than 10 times the number of human cells, which means that the human body is equivalent to 10% cells and 90% microbiota.

The flora in the intestinal lumen includes the following 3 biological layers:

the deep layer is the genus Membrane, which belongs to the beneficial bacteria; the middle layer is the anaerobic bacteria, such as faecal bacteria, digestive streptococcus, etc .;The surface layer is the bacterial flora [1]. The intestinal flora is mainly classified into 9 phylums, including thick-walled phylum, Bacteroides, actinomycetes, Clostridium, Proteus, Warthophytes, Cyanobacteria , Spirochete door and Vadin BE97. Among the gastrointestinal bacteria in healthy humans, Pachyphyte and Bacteroides account for more than 90%, which are the dominant flora.

Type 2 diabetes and its hazards

Diabetes has become the third leading killer after cardiovascular diseases and tumors. There are currently more than 400 million diabetic patients worldwide, and type 2 diabetes accounts for more than 90% in China. Complications such as cardiovascular disease and renal failure caused by diabetes seriously threaten human health and quality of life. At present, the etiology and pathogenesis of diabetes have not been clearly defined, and it is believed to be related to host genes, environment and diet structure. In addition, many studies have found that the type and abundance of intestinal flora and their metabolites and immune regulation have a certain correlation with type 2 diabetes.

Structure of intestinal flora in patients with type 2 diabetes is different from normal population

Some researchers have tested and analyzed the fecal composition of diabetics and healthy people. The number of thick-walled bacteria in the intestinal flora of type 2 diabetes patients decreased significantly, while the number of Gram-negative flora increased. A recent study of the Chinese intestinal flora revealed that compared with normal people, patients with type 2 diabetes have increased numbers of proteobacteria and Enterococcus faecalis, and levels of Plasmodium and Macromonas are higher than normal people. . The number of bifidobacteria and bacilli was reduced, and the reduction of streptococcus was more obvious.

Other studies have found that the concentration of beta proteobacteria increased significantly during diabetes and was positively correlated with blood glucose [3]. Diabetic patients have reduced butyrate-producing bacteria and increased opportunistic bacteria in the intestinal flora [4].

The mechanism of intestinal flora involved in type 2 diabetes

In the mechanism between intestinal flora and type 2 diabetes, It is of great concern that intestinal microorganisms affect regulation mechanism of glucose and energy metabolism through short chain fatty acids.

There are many carbohydrates that the human body cannot digest and decompose. The intestinal flora, especially Bacteroides, Bifidobacterium, Clostridium, Lactobacillus, can produce rich glycoside hydrolase and polysaccharide lyase, which can be used to Carbohydrate hydrolysis is a short-chain fatty acid that is an end product of metabolism. These short-chain fatty acids can strengthen the protective effect of the intestinal barrier, affect the permeability of intestinal epithelial cells and the movement of the upper intestine; increase satiety [5]

Regulation of probiotics on intestinal flora in patients with type 2 diabetes

Studies have found that single probiotics such as Bifidobacterium longum, Bifidobacterium adolescent, and Lactobacillus rhamnosus all have beneficial effects on improving metabolism. Feeding rats with a diet containing a variety of probiotics such as Lactobacillus acidophilus and Lactobacillus casei can significantly improve hyperglycemia, hyperinsulinemia, dyslipidemia, and oxidative stress responses in T2DM rats induced by high fructose, thereby reducing Risk of diabetes and its complications. It was also found that the intake of the probiotic strain Enterococcus faecium EP1 can increase the number of butyrate-producing bacteria (Clostridium Plasmodium), promote the production of mucosal immunoglobulin SIgA and reduce the expression of proinflammatory factors, thereby exerting anti-inflammatory effects .

These research results have shown that regulating the intestinal flora can improve insulin resistance, increase insulin sensitivity, and play a role in regulating blood sugar [6].

In conclusion, there are still many unknown factors in the pathogenesis of diabetes, but there are intestinal flora disorders in patients with type 2 diabetes, which has been supported by a lot of experimental data. It may be one of the ways to prevent and treat diabetes in the future by changing diet structure and using microecological agents to intervene intestinal flora.


[1] Li Xiaoping, Wang Qiaomin, Chu Yuan, et al. Analysis of intestinal target flora in patients with diarrhea type irritable bowel syndrome [J]. Journal of Anhui Medical University, 2014, 49 (5): 655-657

[2]Larsen N, Vogensen FK, Van Den Berg F, et al. Gut Microbiota in Human Adults with Type 2 Diabetes Differs from Non-Diabetic Adults. PLoS One, 2010, 5(2): e9085

[3]Karlsson FH, Tremaroli V, Nookaew, et al. Gut metagenome in European women with normal, impaired and diabetic glucose control [J]. Nature, 2013, 498 (7452): 99-103

[4 ] Qin J, Li Y, Cai Z, et al. A metagenome-wide association study of gut microbiota in type 2 diabetes [J]. Nature. 2012, 490(7418): 55-60

[5] Tian Jiaxing, Li Min, Tong Xiaolin. Research progress on the relationship between intestinal microecology and type II diabetes [J]. Chinese Journal of diabetes, 2018, 26 (08): 688-691

[6] Li Xuelin, Gu Yanyun, Zhang Yifei. Mechanism of probiotics improving type II diabetes [J]. Journal of Shanghai Jiaotong University (Medical Edition), 2017, 37 (09): 1309-1314+1308