Amino acids and glutamate levels in the blood interact with gut microbiota, affect risk of obesity

Certain amino acids in the blood are linked to both obesity and the composition of the gut microbiome, a new study from Lund University in Sweden has revealed. The study, published in the Journal of Clinical Endocrinology and Metabolism, looked at how metabolites in the blood were associated to obesity (the state of having a high body mass index, or BMI) and discover how these obesity-linked metabolites influence the composition of bacterial flora in stool samples.

The gut – rather, the gut microbiome – is a subject that is still ripe for further exploration. Scientists have revealed that the data they currently have is still too little and that most animal studies do not necessarily apply to humans. It is also unique for each person: There is no one-size-fits-all gut microbiome composition, and what may be a healthy bacterial flora composition for one may not necessarily be as healthy for another.

Still, many studies have emerged showing that our gut microbiota has an important function of influencing our overall health, affecting our metabolism and determining our tendency to acquire such diseases as cardiovascular ailments, obesity, insulin resistance, and Type 2 diabetes. This is because the gut microbiota, which includes short-chain fatty acids and amino acids, play an important part in modulating the factors that might contribute to the development of these diseases.

Gut bacteria can change the number of amino acids in the body with how they use amino acids coming from alimentary and endogenous proteins. Furthermore, the disruption of gut microbiota can contribute to an increased risk of – aside from obesity and Type 2 diabetes – chronic inflammatory diseases like inflammatory bowel disease and colorectal cancer.

In this particular study, blood plasma and stool samples were studied from 674 study participants in the Malmo Offspring Study by the research team. They were then able to determine 19 different metabolites that could be related to the person’s BMI. Of these metabolites, branched-chain and aromatic amino acids (BCAA) and glutamate were found to be strongly connected to obesity.

The researchers also discovered that the obesity-related metabolites had an association with four different intestinal bacteria: Blautia, Dorea, and Ruminococcus in the Lachnospiraceae family, and SHA98.

“The differences in BMI were largely explained by the differences in the levels of glutamate and BCAA. This indicates that the metabolites and gut bacteria interact, rather than being independent of each other,” Lund University professor of genetic epidemiology Marju Orho-Melander said.

The researchers also pointed out the fact that previous studies have already linked glutamate to obesity, and BCAA has been looked at as the basis for prediction of the future onset of cardiovascular disease and Type 2 diabetes.

“This means that future studies should focus more on how the composition of gut bacteria can be modified to reduce the risk of obesity and associated metabolic diseases and cardiovascular disease. To get there, we first need to understand what a healthy floral gut looks like, and what factors impact the bacterial composition,” Orho-Melander added.

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Sources include:

Science.news

AlphaGalileo.org

NCBI.NLM.NIH.gov