New discoveries | intestinal flora can affect obesity!

Obesity is a global public health issue. Some research predicts that in 2030, the global obesity population will reach 1.12 billion. Obesity not only brings changes in appearance, but also an important risk factor for metabolic syndrome (MS), diabetes and other diseases. Gut Microbiota maintains symbiotic relationships with host, affecting the body's nutrition, metabolism, and inflammatory response. A number of studies have confirmed that intestinal flora is closely related to metabolic diseases.

But is it a metabolic disease caused by intestinal flora disorders? Or does the metabolic disease cause intestinal flora disorders? The causal relationship between the two is not clear.

Recently, the study published in The Lancet Diabetes and Endocrinology reported on the study of large horizontal cutting surfaces in Norway, confirming that Ruminococcus GNAVUS (RG) was related to multiple metabolic syndrome characteristics, and the weight index (BMI) (BMI) With C-reactive protein does not affect tumor gastric bacteria, there is no reverse causal relationship. These discoveries provide insights on prediction or treatment of metabolic diseases through intestinal flora.

Screenshot source: The Lancet Diabetes and Endocrinology

Researchers issued a total of 55561 questionnaires and stool collection tools, and finally effectively recovered 13268 copies, divided into discovery queues (n = 2875) and two copies (n = 999 and n = 1341). Whether intestinal microorganisms and body fat rates are associated, and possible causal relationships between them.

α diversity and β diversity are common indicators to evaluate the ecology of the flora. The higher α diversity indicates that the number of community species is more, and the number of β diversity represents the number and distribution of species in different communities. The results showed that in the 2875 people's discovery queue, the diversity of flora alpha was negatively related to the body fat rate, that is, the higher the body fat rate, the lower the diversity of the flora alpha. A macroex group and serum metabolic group studies of the intestinal flora of obesity or normal weight of the Chinese population also have similar conclusions. It is found that the diversity of alpha diversity of obesity subjects has decreased, and the diversity of β diversity has increased.

▲ Figure 1: Discover the alpha and β diversity in the queue (Screenshot Source: Reference [7])

In this study, the relative abundance of 11 microorganisms is also related to the body fat rate. It can be seen that the correlation between tumor gastroinus and body fat rate is the strongest, and the correlation between the other two independent queues has also been verified.

▲ Figure 2: The relative abundance of microorganisms in the queue group is found to be related to body fat rate (Screenshot Source: References [7])

Considering that the intestinal microorganisms are easily affected by the mixed factors such as age, gender, diet, drinking, and drugs, researchers have specially corrected mixed factors such as chronic diseases and drugs this time, and found that correlations still exist.

▲ Figure 3: Before and after adjusting the mixed factors, the relationship between the relative abundance of gastrococococcteria and the body fat rate (Screenshot Source: Reference [7])

In the past research, high fat and metabolic syndrome and inflammatory reactions were associated. Is the gastroinus bacteria play a related role?

Researchers have selected fat amounts, weight indexes, waist circumferences, C-Reactive Protein (CRP), and triglyceride as indicators, and found that they are associated with tumor gastrocococi.

The final result of Mendel's randomized analysis shows that the weight index and C-reactive protein do not affect the lively tumor gastrococococcus, and there is no reverse causal relationship. In other words, the abundance of Tumorbacter coccus can cause changes in the weight index and C-reactive protein.

▲ Figure 4: Double sample Mendel randomly analyzes the relationship between BMI and CRP as an ending as exposure and tumor gastric bacteria (Screenshot Source: References 7)

In addition, the genetic risk score (GRS) of the gastrocye and the weight index can independently and superimposed the metabolic characteristics such as the amount of fat volume independent and superimposed. Compared with people who have no tumor -free gastobacteria and the weight index of weight index are lower than those with medium numbers, the genetic risk scores with a gastrocococcterie and the weight index are higher than the median, and the fat content increases by 4.8 kg. Moreover, tumor gastroinus is more correlated with triglyceride and C-reactive protein.

▲ Figure 5: The genetic risk score of the gastrocococcteries and the weight index is the independent and superposition predictive factors of the body fat rate (screenshot source: reference [7])

However, this study did not use the depth macroscopic group sequencing excavation to metabolic syndrome -related specific genes, pathways, and tumor gastric strains, and further research is still needed. The research team hopes that in the future, research can explore whether Tumorbacter can predict cardiac metabolic diseases, and whether the relevant pathway of this flora can be used as the target of metabolic diseases.

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