By Julia Haimovich, Accredited Practicing Dietitian.
Preservatives in food play a crucial role in maintaining food safety and extending shelf life by inhibiting microbial growth, preventing spoilage, and reducing the risk of foodborne illnesses. However, concerns have been raised regarding their potential impact on human health, particularly their effects on physiology, metabolism, and biology within the human body. 1
When ingested, food preservatives encounter various physiological processes within the human body. For instance, sodium benzoate, a commonly used preservative, is metabolised in the liver, where it is converted to benzoic acid and eventually eliminated via urine.
However, high levels of sodium benzoate intake have been linked to adverse health effects, including allergic reactions, asthma, and hyperactivity, especially in susceptible individuals. 2
Similarly, sulphites, another group of preservatives commonly used to prevent browning and microbial growth in foods like dried fruits and wine, can trigger allergic reactions in sensitive individuals. These reactions may manifest as respiratory symptoms, gastrointestinal disturbances, or skin irritation due to sulphite sensitivity or intolerance. 3
The metabolism of preservatives can vary depending on factors such as individual genetics, dietary habits, and gut microbiota composition. The gut microbiota, comprising trillions of microorganisms inhabiting the gastrointestinal tract, plays a crucial role in metabolising dietary components, including food additives and preservatives. Recent research has highlighted the interplay between gut microbiota composition and host health, suggesting that alterations in microbial diversity and function may influence susceptibility to certain diseases and metabolic disorders. 4
In contrast to synthetic preservatives, gut-derived nisin-like lantibiotics offer a natural alternative for combating harmful bacteria in the food and the gut while preserving beneficial gut flora. Nisin, a well-studied lantibiotic produced by Lactococcus lactis, exhibits potent antimicrobial activity against a broad spectrum of gram-positive bacteria, including several pathogens commonly associated with foodborne illnesses, such as Listeria monocytogenes. 5
The mechanism of action of nisin involves disrupting bacterial cell membrane integrity, leading to leakage of intracellular contents and, ultimately, cell death. Importantly, nisin selectively targets certain pathogenic bacteria while sparing beneficial commensal microbes, such as Lactobacillus and Bifidobacterium species, which play key roles in maintaining gut homeostasis and host health. 5
Moreover, recent studies have identified gut-derived nisin-like lantibiotics produced by commensal bacteria within the human gut microbiota. These endogenous antimicrobial peptides, synthesised by resident bacteria such as Streptococcus, Enterococcus, and Lactobacillus species, contribute to the defence against invading pathogens and the regulation of microbial populations within the gut ecosystem. 5
The discovery of gut-derived nisin-like lantibiotics underscores the importance of symbiotic interactions between the host and its indigenous microbial community in shaping gut health and immunity. Harnessing the therapeutic potential of these endogenous antimicrobial peptides may offer novel strategies for modulating the gut microbiota composition and combating gastrointestinal infections without disrupting the delicate balance of the microbiome. 5
In summary, while synthetic preservatives are important in food preservation, their potential health risks warrant careful consideration, especially for individuals with sensitivities or intolerances. Gut-derived nisin-like lantibiotics represent a promising avenue for addressing microbial imbalances in the gut and mitigating the risks associated with synthetic preservative consumption. Further research is needed to elucidate synthetic and natural preservatives’ physiological effects and long-term implications on human health and gut microbiota dynamics.
1. Sambu S, Hemaram U, Murugan R, Alsofi AA. Toxicological and Teratogenic Effect
of Various Food Additives: An Updated Review [retracted in: Biomed Res Int. 2024
Jan 9;2024:9792751]. Biomed Res Int. 2022;2022:6829409. Published 2022 Jun 24.
doi:10.1155/2022/6829409
2. Sambu S, Hemaram U, Murugan R, Alsofi AA. Toxicological and Teratogenic Effect
of Various Food Additives: An Updated Review [retracted in: Biomed Res Int. 2024
Jan 9;2024:9792751]. Biomed Res Int. 2022;2022:6829409. Published 2022 Jun 24.
doi:10.1155/2022/6829409
3. Dordevic D, Capikova J, Dordevic S, Tremlová B, Gajdács M, Kushkevych I. Sulfur
content in foods and beverages and its role in human and animal metabolism: A
scoping review of recent studies. Heliyon. 2023;9(4):e15452. Published 2023 Apr 13.
doi:10.1016/j.heliyon.2023.e15452
4. Zhou X, Qiao K, Wu H, Zhang Y. The Impact of Food Additives on the Abundance
and Composition of Gut Microbiota. Molecules. 2023;28(2):631. Published 2023 Jan
7. doi:10.3390/molecules28020631
5. ACS Chem. Biot. 2024, 19, 2, 357–369 Publication Date:January 31, 2024
