Link between Gut Bacteria and Body Weight

Earlier research has proposed that weight may be stimulated by genes. A recent study develops on this concept, showing that our genetic makeup shapes what kind of bacteria live in the gut, which may impact how heavy we are.

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The results come from a twin study performed by investigators from Cornell University in Ithaca and King’s College London in the.

The study team, which includes Prof. Tim Spector, head of the Department of Twin Research and Genetic Epidemiology, says the outcomes may open the entrance to personalized probiotic therapies that could decrease the threat of obesity and its relevant diseases.

For their research, presented in the journal Cell, the scientists sequenced the genes of microbes existing in over 1,000 fecal samples obtained from 416 pairs of twins who were part of the Twins UK data registry.

Of these twins, 171 pairs were similar and 245 were non-similar. Identical twins share 100% of their genes, while non-identical twin babies share about 50% of their genes.

Raising specific strain of bacteria in the gut ‘could decrease, prevent obesity’

Outcomes of the research exposed that identical twin babies had a similar variety of particular types of gut bacteria, in comparison with non-identical twins. The group says this signifies that genes influence the kind of bacteria present in the gut.

What is more, the scientists identified that the existence of a class of bacteria known as Christensenellaceae was most affected by genes. A specific strain of this bacteria – Christensenellaceae minuta – was identified to be more common among people of a low body weight.

On adding this bacteria to the guts of mice, the group identified the animals obtained less weight than those that didn’t to receive the bacteria. This indicates that raising the amount of Christensenellaceae minuta bacteria in the gut could help to decrease or protect against obesity, the experts say.

Leaving comments on their outcomes, Prof. Spector says:

“Our discoveries show that particular groups of microbes living in our gut could be protective against obesity – and that their abundance is affected by our genes. The human microbiome shows an interesting new target for dietary modifications and therapies aimed at combating obesity.”

Senior author Ruth Ley, notes that this research is the initial to identify that particular gut microbes are heritable and that the difference of these microbes is not completely affected by diet, environment, lifestyle and health.

Other ways in which gut bacteria may perform a role in obesity

Several other researches have revealed on the association between obesity and gut bacteria, but all of them have various theories.

The scientists of that research, from Washington State University, describe that the fibers and polyphenols existing in Granny Smith apples are unscathed when they arrive at the colon, even after exposure to stomach acid and digestive enzymes. The bacteria in the colon then ferment these substances, generating butyric acid that activates the growth of good gut bacteria.

Another research, claimed in July, detailed the creation of a probiotic that scientists say could prevent obesity.

Senior study author Sean Davies, of Vanderbilt University in Nashville, TN, and co-workers genetically modified a strain of bacteria that colonizes the human gut – Escherichia coli Nissle 1917 – to generate a substance known as N-acyl-phosphatidylethanolamine (NAPE), which can reduce food intake.

On giving this bacteria to mice fed a high-fat diet plan for 8 weeks, the team identified that it considerably decreased their food consumption, body fat and occurrence of hepatosteatosis (fatty liver), in comparison with control mice.