Emulsifiers may disrupt gut bacteria
Emulsifiers May Disrupt Gut Bacteria
A recent report shows that emulsifiers disrupt
intestinal bacteria in mice to cause inflammation
and weight gain (Nature, Feb 25, 2015). Emulsifiers
are added to many foods, such as ice cream, salad
dressing, pastas, bread and cookies, to prolong
shelf life and keep ingredients from separating. If
these same results are found in humans, emulsifers
may be shown to increase risk for inflammation,
ulcerative colitis, Crohn’s disease, weight gain,
central obesity, insulin insensitivity, and
Researchers fed the emulsifiers
carboxymethylcellulose and polysorbate-80, at doses
comparable to what humans eat in processed foods, to
mice for 12 weeks. The mice's gut bacteria
penetrated into the intestinal lining, instead of
staying on the surface where they belong. This
turned on their immunity against these bacteria, as
demonstrated by making proteins that are signs of an
overactive immunity (inflammation). They also gained
a lot of extra weight. Another group of mice that
had been treated to have no gut bacteria had none of
these effects when fed the emulsifiers. When
researchers transplanted bacteria from the original
group of mice into the group with no previous
bacteria or symptoms, the recipient mice developed
all the same changes exhibited in the original
group, which showed that the emulsifiers had changed
the gut bacteria.
Application of This Study to Humans
Your intestines contain more than 100 trillion
bacteria (about four pounds). The bacteria are
prevented from piercing your intestines by a thick
mucus layer that covers the entire inner lining.
Emulsifiers are detergent-like molecules that can
break down this thick mucous layer and allow the
bacteria to penetrate the inner linings of your
intestines. Your immune system responds to these
invading bacteria by producing all the chemicals
that it uses to kill germs and prevent infections.
This overactive immunity, called inflammation, may
be the cause of the marked increase in inflammatory
bowel diseases (ulcerative colitis and Crohn’s
disease) that has occurred in the last 70 years.
Emulsifiers can also cause blood sugars to rise to
high levels and increase the absorption of foods.
The emulsifiers made the mice fat (particularly in
their bellies), prevented them from responding to
insulin and caused them to develop diabetes. We do
not yet know whether the same results occur in
What are Emulsifiers?
Emulsifiers hold food ingredients together.
Mayonnaise without emulsifiers would separate into
an oily top layer and a thick white bottom layer.
Foods that may contain emulsifiers include
margarine, mayonnaise, salad dressings, creamy
sauces, candies, ice cream, fast-food shakes, baked
goods and many other processed foods. Emulsifiers
are also found in a large number of the prescription
and over-the-counter drugs on the market today. They
are used to improve the consistency of gel capsules,
make pills dissolve in the stomach, and keep
medication suspended in liquid form.
What Does This Mean for You?
This is a well done study that should make you
think about eating processed foods that have lots of
added chemicals, many of which have never been
tested for consequences in humans. If future studies
confirm this one, you will want to avoid
emulsifiers. In general, it is more healthful to eat
foods as they are found in nature, such as fruits,
vegetables, nuts, beans and other seeds, and to
restrict foods that have been processed with added