Common Food Preservative Has Unexpected Effects on the Gut Microbiome

Food manufacturers often add preservatives to food products to keep them fresh. A primary purpose of these preservatives is to kill microbes that could break down and otherwise spoil the food. 

Common additives like sugar, salt, vinegar and alcohol have been used as preservatives for centuries, but modern-day food labels now reveal more unfamiliar ingredients such as sodium benzoate, calcium propionate, and potassium sorbate.

Bacteria produce chemicals called bacteriocins to kill microbial competitors. These chemicals can serve as natural preservatives by killing potentially dangerous pathogens in food.

Lanthipeptides, a class of bacteriocins with especially potent antimicrobial properties, are widely used by the food industry and have become known as “lantibiotics” (a scientific portmanteau of lanthipeptide and antibiotics).

Despite their widespread use, however, little is known about how these lantibiotics affect the gut microbiomes of people who consume them in food.

Microbes in the gut live in a delicate balance, and commensal bacteria provide important benefits to the body by breaking down nutrients, producing metabolites, and — importantly — protecting against pathogens.

If too many commensals are indiscriminately killed off by antimicrobial food preservatives, opportunistic pathogenic bacteria might take their place and wreak havoc — a result no better than eating contaminated food in the first place.

A new study published in ACS Chemical Biology by scientists from the University of Chicago found that one of the most common classes of lantibiotics has potent effects both against pathogens and against the commensal gut bacteria that keep us healthy.

Nisin is a popular lantibiotic used in everything from beer and sausage to cheese and dipping sauces. It is produced by bacteria that live in the mammary glands of cows, but microbes in the human gut produce similar lantibiotics too.

The researchers found that while the different lantibiotics had varying effects, they killed pathogens and commensal bacteria alike.

Zhang and his team also studied the structure of peptides in the lantibiotics to better understand their activity, in the interest of learning how to use their antimicrobial properties for good.

They are also studying the prevalence of lantibiotic-resistant genes across different populations of people to better understand how such bacteria can colonize the gut under different conditions and diets.


Zhenrun J. Zhang, Chunyu Wu, Ryan Moreira, Darian Dorantes, Téa Pappas, Anitha Sundararajan, Huaiying Lin, Eric G. Pamer, Wilfred A. van der Donk. Activity of Gut-Derived Nisin-like Lantibiotics against Human Gut Pathogens and Commensals. ACS Chemical Biology, 2024; DOI: 10.1021/acschembio.3c00577

University of Chicago. (2024, February 2). Common food preservative has unexpected effects on the gut microbiome. ScienceDaily. Retrieved February 5, 2024 from

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