Does Our Gut Microbiome Adapt to Food Preservatives?
All of us are paying closer attention to the food we eat, where it’s sourced, what’s in it, and how it’s made. Additives and preservatives are something we rarely think about as they seem to be invisible. There’s also incredible attention being paid to the bacteria in our gut (microbiome). However, can the additives in our food impact that microbiome?
3,000 Food Additives and Counting
If there is one thing we don’t have a short supply of in the U.S., it’s food additives, including food preservatives. The FDA currently has a list of over 3,000 approved food additives. So why do we add things to our food, and what exactly are we adding?
We add things to our food for many reasons: because it spoils, because our modern tongue likes everything a little sweeter, because food its prettier if its green is greener or its red is redder, because turbocharging our juice with enhanced vitamins and minerals helps fill in our nutritional gaps, and the list goes on.
Food additives can be found in everything from fresh produce to processed foods, jarred and canned foods, cereal, cured and processed meats, breads, cheeses, soft drinks, juices, and so much more. You may not know what preservatives are used on your fresh produce; however, turn over a box of any packaged food, and you’ll likely see the long list of food additives. A few of the approved 3,000 include the following:
- Preservatives (e.g., ascorbic acid and benzoate)
- Sweeteners (e.g., high fructose corn syrup, sucrose, aspartame)
- Dyes (e.g., FD&C Green No. 3, caramel color, Citrus Red No. 2)
- Flavorings—(e.g., “natural flavoring” or “artificial flavors added”)
- Flavor enhancers (e.g., monosodium glutamate [MSG], disodium guanylate)
- Fat additives (e.g., olestra, xantham gum, modified food starch)
- Nutrients (e.g., riboflavin, beta carotene, vitamin D)
In addition to these, there are additives that emulsify, thicken, leaven, firm, carbonate, modify proteins and fats, and so much more.
So while these additives may be making our foods prettier and sweeter and extending their shelf life, are they doing our body any favors? The answer really depends on each individual additive. A new study, however, does suggest one food preservative may be disrupting our gut microbiome…at least temporarily. We’ll take a look at the study in a minute; first, let’s review the gut microbiome.
Our Gut Microbiome
Our gut microbiome is the environment inside our gut. It consists heavily of bacteria, but other microbes live there as well, such as parasites and yeasts. Don’t confuse gut bacteria with an infection. While you can indeed acquire an infection in your gut, what we are talking about today is both the good and bad gut bacteria that must be balanced and diverse for our gut to properly function. Our goal is to feed and grow the good bacteria while at the same time taming and minimizing the bad. Why? There are many, many reasons, but a few follow:
- Parkinson’s disease may actually start in the gut.
- Bad gut bacteria may damage your stem cells; good gut bacteria may be beneficial to stem cells.
- A healthy diet and the right gut bacteria may help you lose weight.
- Artificial sugars (a food additive) can disturb gut bacteria, causing an increase in insulin secretion.
Study on One Food Preservative Highlights the Possibility of Gut Resiliency
The focus of the new study was specifically to study the effects of an antimicrobial preservative on the gut. Antimicrobial food additives preserve food by either killing or slowing the growth of microorganisms such as bacteria and mold. Antimicrobials delay spoilage. The antimicrobial used in the study was polylysine.
Eighty young mice were randomly divided into four separate groups. One group (the control group) was given maltodextrin (an artificial sweetener). The second group was given maltodextrin with polylysine (the antimicrobial preservative). The third group was given maltodextrin and pectin (a thickening additive). And the fourth group was given maltodextrin, polylysine, and pectin. The feces of the mice were studied at weeks one, five, and nine.
The results? Researchers found that polylysine disturbed the bacterial diversity in the gut. This effect was, however, temporary, and by the end of the study, the conditions in the gut had surprisingly returned to normal. In effect, the gut seemed to adapt to the ongoing consumption of polylysine. The effect on health during this disruption in the gut was not within the scope of this study, and human follow-up would need to be done, but researchers contrasted this result with the lack of gut resiliency to antibiotics, which can heavily disturb the gut microbiota throughout the duration of and following antibiotic use.
The upshot? The bad news, polylysine messes with a rat’s microbiome, but the gut bacteria is able to recover. How it impacts a human microbiome remains to be seen. In the meantime, I know I’ll be checking food labels for this stuff!