A common preservative used in food products, from beer to sausages and cheese, has the potential to interact with the human gut microbiome in unexpected and perhaps harmful ways, according to a new study.
These latest findings, from researchers at the University of Chicago and the University of Illinois at Urbana-Champaign, raise more questions about whether or not preservatives intended to kill pathogens in food could also be harming our internal mix of bacteria.
“Nisin “It is, in essence, an antibiotic that has been added to our foods for a long time, but how it might affect our gut microbes has not been well studied,” says microbiologist Zhenrun Zhang, from the University of Chicago.
“Although it could be very effective in preventing food contamination, it could also have a greater impact on our human gut microbes.”
Belonging to a class of preservatives called lantibiotics, nisin is a protein that contains unusual amino acids that affect microbial function without directly harming animals. Here, Zhang and his colleagues referenced genetic databases to prepare six nisin-like substances, which were then tested in a laboratory against beneficial and harmful bacteria in the human intestine.
Each lantibiotic produced different results, but all were observed to affect both. dangerous bacteria (pathogens) and microbes that help maintain a healthy intestine (commensal bacteria).
We’re still a long way from being able to say that food preservatives are harmful to our stomachs, but research shows that these chemicals have the potential to interfere with a healthy gut microbiome in ways we may not have anticipated.
“This study is one of the first to demonstrate that gut commensals are susceptible to lantibiotics and are sometimes more sensitive than pathogens.” says Zhang.
“With the levels of lantibiotics currently present in foods, it is very likely that they also affect our intestinal health.”
Over the years, additives such as salt or alcohol have been replaced by more exotic ingredients as ways to keep foods fresh and shelf-stable for longer, essentially stopping bacteria and mold spreads easily and spoils food.
And there is a growing amount of recent research suggesting that the way we treat and process our food is doing our health no good. At the very least, it’s worth taking a closer look at the balance between good and bad bacteria.
Note that nisin-like lantibiotics also occur naturally in the human intestine, but it remains to be seen whether the higher amounts provided by processed foods are indirectly causing harm.
“It seems that lantibiotics and lantibiotic-producing bacteria are not always good for health, so we are looking for ways to counteract the possible bad influence while taking advantage of their more beneficial antimicrobial properties.” says Zhang.
The research has been published in ACS Chemistry Biology.