Common food additives alter gut microbes, causing inflammation, colitis, obesity and diabetes

(NaturalNews) A class of food additives used in nearly all processed foods may be partially to blame for inflammatory bowel diseases (IBD) such as Crohn's disease, and may also lead to obesity and diabetes, according to a study conducted by researchers from Cornell University, Emory University, Georgia State University and Bar-Ilan University in Israel, and published in the journal Nature on February 25.

The study was funded by the Crohn's & Colitis Foundation of America and the National Institutes of Health.

The researchers found that emulsifiers, detergent-like additives used to improve the texture of food and lengthen its shelf life, alter the composition of the gut's microbiota. This change leads to an increase in inflammation that has been linked with various health conditions.

"These results ... suggest that the broad use of emulsifying agents might be contributing to an increased societal incidence of obesity/metabolic syndrome and other chronic inflammatory diseases," the researchers wrote.

The importance of gut bacteria

The human gut is home to roughly 100 trillion bacteria of a wide variety of different species, collectively known as the microbiota or microbiome. The microbiome is known to play a key role in metabolism and immune function, and prior studies have shown that a disturbed microbiome could play a role in certain chronic inflammatory diseases. Studies have also shown that people who suffer from both IBD and metabolic syndrome have abnormal microbiota.

"A key feature of these modern plagues is alteration of the gut microbiota in a manner that promotes inflammation," said researcher Andrew T. Gewirtz.

Metabolic syndrome is a group of symptoms (such as central obesity and high fasting blood sugar) associated with an increased risk of heart disease, type 2 diabetes and liver disease. It has been linked with high levels of systemic inflammation. IBD, which includes Crohn's disease and ulcerative colitis, is a chronic and often debilitating inflammation of the digestive tract that can have serious health consequences. Both conditions have increased in prevalence dramatically since the middle of the 20th century.

"The dramatic increase in these diseases has occurred despite consistent human genetics, suggesting a pivotal role for an environmental factor," researcher Benoit Chassaing said. "Food interacts intimately with the microbiota so we considered what modern additions to the food supply might possibly make gut bacteria more pro-inflammatory."

Disrupted bacteria actually produce overeating

The addition of emulsifiers to foods roughly corresponded with the increase in both conditions. In addition, prior studies have shown that, by dissolving the mucus layer that covers the intestinal wall, emulsifiers can allow gut bacteria access to the epithelial cells lining the intestine - an area that they are normally kept out of. This bacterial migration could in turn produce inflammation of the gut.

To test this idea, the researchers fed mice the common emulsifiers polysorbate 80 and carboxymethylcellulsose at doses comparable to those found in processed foods. They found that as expected, the microbiota of the mice changed to a more pro-inflammatory makeup. In addition, the microbiota gained an increased ability to digest and penetrate the mucus layer of the intestine, and produced more pro-inflammatory chemicals.

In mice with abnormal immune systems, this led to the development of chronic colitis. In mice with normal immune systems, it led to mild intestinal inflammation and metabolic syndrome (including obesity, insulin resistance, high blood sugar and increased appetite).

When the experiment was repeated in mice lacking a microbiome, no inflammation or metabolic syndrome occurred.

"Our findings reinforce the concept suggested by earlier work that low-grade inflammation resulting from an altered microbiota can be an underlying cause of excess eating," Gewirtz said.

The findings strongly support the idea that disruption of the microbiome can produce inflammatory gut diseases. They also suggest, the researchers noted, that current food safety testing measures are inadequate, as they do not look for low-grade inflammatory effects.

(Natural News Science)

Sources:

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