Widely used food additive promotes colitis, obesity and metabolic syndrome, research shows

Widely used food additive promotes colitis, obesity and metabolic syndrome, research shows
This photo shows bacteria that are present deeper in the mucus layer that lines the intestine and closer to the epithelium than they should be. Credit: Dr. Benoit Chassaing

Emulsifiers, which are added to most processed foods to aid texture and extend shelf life, can alter the gut microbiota composition and localization to induce intestinal inflammation that promotes the development of inflammatory bowel disease and metabolic syndrome, new research shows.

The research, published Feb. 25 in Nature, was led by Georgia State University Institute for Biomedical Sciences' researchers Drs. Benoit Chassaing and Andrew T. Gewirtz, and included contributions from Emory University, Cornell University and Bar-Ilan University in Israel.

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, afflicts millions of people and is often severe and debilitating. Metabolic syndrome is a group of very common obesity-related disorders that can lead to type-2 diabetes, cardiovascular and/or liver diseases. Incidence of IBD and metabolic syndrome has been markedly increasing since the mid-20th century.

The term "gut microbiota" refers to the diverse population of 100 trillion bacteria that inhabit the intestinal tract. Gut microbiota are disturbed in IBD and metabolic syndrome. Chassaing and Gewirtz's findings suggest emulsifiers might be partially responsible for this disturbance and the increased incidence of these diseases.

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

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

Addition of emulsifiers to food seemed to fit the time frame and had been shown to promote bacterial translocation across epithelial cells. Chassaing and Gewirtz hypothesized that emulsifiers might affect the gut microbiota to promote these inflammatory diseases and designed experiments in mice to test this possibility.

The team fed mice two very commonly used emulsifiers, polysorbate 80 and carboxymethylcellulsose, at doses seeking to model the broad consumption of the numerous emulsifiers that are incorporated into almost all processed foods. They observed that emulsifier consumption changed the species composition of the and did so in a manner that made it more pro-inflammatory. The altered microbiota had 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.

Such changes in bacteria triggered chronic colitis in mice genetically prone to this disorder, due to abnormal immune systems. In contrast, in mice with normal immune systems, emulsifiers induced low-grade or mild intestinal inflammation and metabolic syndrome, characterized by increased levels of food consumption, obesity, hyperglycemia and insulin resistance.

The effects of emulsifier consumption were eliminated in germ-free mice, which lack a microbiota. Transplant of microbiota from emulsifiers-treated mice to germ-free mice was sufficient to transfer some parameters of low-grade inflammation and metabolic syndrome, indicating a central role for the microbiota in mediating the adverse effect of emulsifiers.

The team is now testing additional emulsifiers and designing experiments to investigate how emulsifiers affect humans. If similar results are obtained, it would indicate a role for this class of food additive in driving the epidemic of obesity, its inter-related consequences and a range of diseases associated with chronic gut inflammation.

While detailed mechanisms underlying the effect of on metabolism remain under study, the team points out that avoiding excess food consumption is of paramount importance.

"We do not disagree with the commonly held assumption that over-eating is a central cause of obesity and ," Gewirtz says. "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."

The team notes that the results of their study suggest that current means of testing and approving food additives may not be adequate to prevent use of chemicals that promote diseases driven by low-grade inflammation and/or which will cause disease primarily in susceptible hosts.


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Healthy gut microbiota can prevent metabolic syndrome, researchers say

More information: Nature DOI: 10.1038/nature14232
Journal information: Nature

Citation: Widely used food additive promotes colitis, obesity and metabolic syndrome, research shows (2015, February 25) retrieved 19 October 2019 from https://medicalxpress.com/news/2015-02-widely-food-additive-colitis-obesity.html
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Feb 25, 2015
Why not feed mice some McDonald's food and see how long it takes before they explode? O.O

Feb 25, 2015
Whole foods or bust. The processed industry is a scourge. Ban it all already.

Feb 25, 2015
Over eating may not be the cause of metabolic syndrome, but it is the cause of obesity.

You cannot gain mass without consuming it. Everyone here knows this. Emulsifiers may increase your desire to eat, or reduce your metabolic rate, but in either case, eating more mass/energy than you expend is still the cause of obesity.

If you weigh too much, eat less, period.

Feb 25, 2015
Over eating may not be the cause of metabolic syndrome, but it is the cause of obesity.

You cannot gain mass without consuming it. Everyone here knows this. Emulsifiers may increase your desire to eat, or reduce your metabolic rate, but in either case, eating more mass/energy than you expend is still the cause of obesity.

If you weigh too much, eat less, period.


If your going to make such sweeping claims you need to back it up with some peer reviewed empirical evidence. For much of my life I would have agreed with you but science trumps intuition everytime.

Feb 25, 2015
Whole foods or bust. The processed industry is a scourge. Ban it all already.


I'll agree that processed foods should be avoided but without a massive and persuasive educational effort demonstrating healthful meals can be prepared as easily and as cheaply as hamburger helper it isn't going to happen.

Feb 26, 2015
More poisoned fruit from the abomination of corporate agribusiness. Most of this garbage was dumped into our food after WW2; you see the result. Before that, most Americans were fit. All these additives should be outlawed.

Feb 26, 2015
Polysorbate 80 has been linked to infertility. It should not be in our food.

Feb 26, 2015
If we had a sane policy on extending shelf life of food, we would irradiate it. But thanks to Hollywood, policymakers are like lemmings.

Feb 26, 2015
If one takes into account many people's behavior with respect to e.g. smoking, I'm not buying this quote:

I'll agree that processed foods should be avoided but without a massive and persuasive educational effort demonstrating healthful meals can be prepared as easily and as cheaply as hamburger helper it isn't going to happen.


Feb 26, 2015
@Nattydread

Polysorbate 80 has been linked to infertility. It should not be in our food.


There should be more of it in everyone's food.

https://en.wikipe...pulation

Mar 02, 2015
anyone who thinks all mass or calories is equal in its impact on obesity needs to see this

https://www.youtu...niua6-oM

Mar 03, 2015
If you weigh too much, eat less, period.


There's just no way around good old physics.


Mar 03, 2015
I would really want to know in which way a rodent's guts and rodent physiology is similar to a the guts of an omnivorous simian evolved to digest cooked food.

It is BTW not the first they they utterly f***k it up comparing mice to humans, just recall the case of mustard oil, deadly to mice but consumed by billions in Asia.

But well, I agree that scientists are human too and have a right to amuse themselves vivisecting some critters ;)

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