A recent study gives support to eating a diet with real unprocessed foods and avoiding foods with additives as much as possible. The study found that the commonly used food additive known as xanthan gum (E415 in Europe) can cause disruptions to our gut microbiome.
The gut microbiome or microbiota is the community of microbes living in our intestines, and which are critical to good health. The international team of researchers found that the gut microbes changed when exposed to the additive, so as to be able to digest the xanthan gum.
Xanthan gum is used as a thickener or stabilizer in many foods, including ice cream, sweets, chocolate milk, baked goods, ready-made sauces and dressings. [Note: If present, it is listed in the ingredients on food labels.]
Bottom line: Rather than being harmless and not having any effects, food additives may have effects on or disrupt our gut microbes. Food additive effects may be minimal or can actually cause harm. For example, some emulsifiers (e.g., soy lecithin, carrageenan, polysorbate-80) can promote gut inflammation and alter the gut microbiome in a negative or harmful way
From Medical Xpress: Widely used food additive affects the human gut microbiota
Have you heard about the food additive E415? It is also known as xanthan gum. Most likely, you eat it several times a week. Xanthan gum is used in everyday foods such as baked goods, ice cream and salad dressings. The additive is also widely used as a substitute for gluten in gluten-free foods.
New research now shows that xanthan gum affects our gut microbiota.
When it was first introduced, xanthan gum was thought to not affect us as it was not digested by the human body. However, the new study shows that the additive nevertheless affects the bacteria that live in our intestines. And these bacteria are important for our health and well-being.
"The gut bacteria we have investigated show genetic changes and a rapid adaptation to enable them to digest this particular additive," explains professor Phil Pope.
The study shows that the ability to digest xanthan gum is surprisingly common in the human gut microbiota in the industrialized world and appears to depend on the activity of a single bacterium that is a member of the family Ruminococcaceae.
"The bacterium that can digest xanthan gum was found among the gut microbiota of surprisingly many people from industrialized countries," says La Rosa.
In some samples, another type of microbe was also found that interacted with the xanthan gum, this one in the species Bacteroides intestinalis. This bacterium could hijack and further break down small pieces of xanthan gum created during the digestion of the larger xanthan molecules by the Ruminococcaceae bacterium. The Bacteroides bacterium was equipped with its own special enzymes that allowed it to eat these small xanthan gum fragments.
The additive was developed in California in the sixties and was approved as safe for use in food by the U.S. Food Safety Authority in 1968. It is used today across much of the industrialized world.
However, she explains, the new study shows that gut bacteria break down xanthan gum to its constituent monosaccharides, which are subsequently fermented to produce short-chain fatty acids that can be assimilated by the human body. Short-chain fatty acids are known to supply up to 10 percent of calories to humans. This suggests xanthan gum could in fact add to a person's calorie intake.
Starting to see long-term effects
When xanthan gum was first introduced, it was thought that the additive went straight through the body without affecting the person who ate it.
Xanthan gum is a different type of carbohydrate from those that the human body is used to consume, such as starch from plant food. It has a different chemical structure. Xanthan gum is a type of complex carbohydrate that is not similar to any of the plant fibers we normally eat.
"We only see these changes in gut bacteria of people eating a 'westernized diet' where processed foods and additives make up a significant part of the food intake. For example, we do not see the same changes in indigenous people from different parts of the globe who eat limited amounts of processed foods."
What does it mean for our health?
"Based on this study, we cannot conclude if and how xanthan gum affects our health. But we can say that the additive affects the microbiota in the gut of people who consume it through food," says La Rosa.