Emulsifiers act by binding two opposites together. Normally oil and water separate; however, the emulsifier contains both a water-loving hydrophilic head and an oil-loving hydrophobic tail. The addition of an emulsifier to certain substances prevents separation of two opposing products and generates a stable food product.
A new study published in the Nature journal, highlights that emulsifiers can alter your gut bacteria producing intestinal inflammation allowing the development of inflammatory bowel disease and metabolic syndrome.
Millions of people are affected by inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis. Metabolic syndrome is a recent term developed to describe obesity-related disorders that can lead to type-2 diabetes, cardiovascular and/or liver diseases.
The researchers investigated the role of emulsifiers as the number of people afflicted by metabolic syndrome and inflammatory disease has been steadily increasing over the years.
“A key feature of these modern plagues is alteration of the gut microbiota in a manner that promotes inflammation,” said Dr. Andrew Gewirtz one of the lead researchers of the study at the Georgia State University Institute for Biomedical Sciences.
“The dramatic increase in these diseases has occurred despite consistent human genetics, suggesting a pivotal role for an environmental factor,” said Dr. Bennoit Chassaing, the second study author. “Food interacts intimately with the microbiota so we considered what modern additions to the food supply might possibly make gut bacteria more pro-inflammatory.”
The study consisted of feeding mice two very commonly used emulsifiers, polysorbate 80 and carboxymethylcellulsose. The doses given to the mice were designed to mimic the broad consumption of the numerous emulsifiers that are incorporated into almost all processed foods. It was observed that emulsifierconsumption changed the species composition of the gut bacteria in a way that increased inflammation. The altered bacteria had an enhanced capacity to digest and infiltrate the dense mucus layer that lines the intestine, which is normally, largely devoid of bacteria. Alterations in bacterial species resulted in bacteria expressing more flagellin and lipopolysaccharide, which can activate pro-inflammatory gene expression by the immune system.
It was observed that mice developed chronic colitis due to an abnormal immune system. In direct contrast mice with normal immune systems, who were fed emulsifiers, developed low-grade or mild intestinal inflammation and metabolic syndrome, characterized by increased levels of food consumption, obesity, hyperglycemia and insulin resistance.
“We do not disagree with the commonly held assumption that over-eating is a central cause of obesity and metabolic syndrome,” said Gewirtz. “Rather, 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.”
Benoit Chassaing, Omry Koren, Julia K. Goodrich, Angela C. Poole, Shanthi Srinivasan, Ruth E. Ley, Andrew T. Gewirtz. Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature, 2015; DOI: 10.1038/nature14232