The food additive butylated hydroxyanisole minimally affects the human gut microbiome ex vivo

Authors: Scarino Lemons, Johanna; Narrowe, Adrienne; Firrman, Jenni; Mahalak, Karley; Liu, Lin; HIGGINS, STEPHANIE - Children'S Hospital - Philadelphia, Pennsylvania; MOUSTAFA, AHMED - Children'S Hospital - Philadelphia, Pennsylvania; BAUDOT, AURELIEN - Cryptobiotix; DEYAERT, STEF - Cryptobiotix; VAN DEN ABBEELE, PIETER - Cryptobiotix

Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: The world’s population is steadily rising and is expected to reach 9 billion by 2050. Ensuring global food security for this growing population is an ongoing challenge that will require increased sustainable food production and reduced food loss via food preservation techniques. For these techniques to be accepted by consumers, and benefit the growing population, they must be safe. A widely used food preservative that continues to raise consumer concern, was analyzed for negative impact on gut microbiota health in individuals across the lifespan. While the preservative did cause small but significant decreases in the abundance of some gut bacteria, these changes were not large enough to alter community composition or function for any age group. Previous research demonstrated that this preservative was capable of interfering with cellular respiration machinery and our study revealed that bacteria with this machinery were more likely to be negatively affected than those without it. The preservative dose used in this study was designed to be ten times higher than the recommended amount and even at this dose, the effects on the gut microbiome were minimal.

Technical Abstract: The synthetic antioxidant butylated hydroxyanisole (BHA) continues to raise consumer concern due to its status as a “possible carcinogen” even though the U.S. Food and Drug Administration, and other regulatory bodies, consider BHA safe when below a regulated amount. Because BHA is ingested along with the foods it is added to and it is known to survive digestion and enter the colon, an investigation into its effect on the human gut microbiome was undertaken. Fermentation parameters (pH, gas, short-chain fatty acids) were monitored and the composition of the gut community were assessed after ex vivo incubation of fecal material from 24 donors with and without BHA treatment. A BHA dose of 0.35g/L elicited no statistically significant changes in the functional outputs or community structure for any age group, as measured by alpha and beta diversity metrics. Although not large enough to affect the overall community composition, there were a few significant decreases at the phylum level for Proteobacteria among toddlers and for Bacteroidota for adults. When all age groups are considered together, the list of phyla that significantly decrease lengthens to also include Verrucomicrobiota, Firmicutes C, Actinobacteriota and Desulfobacterota I. Among the genes that are most significantly affected by treatment with BHA across age groups are those involved in lipopolysaccharide synthesis and bacterial electron transport which are encoded by mostly gram-negative species within the Bacteroidota, Proteobacteria and Verrucomicrobiota phyla. In the context of what is already known about the intracellular activity of BHA from other studies, these genes may also provide a clue as to the mechanism behind its evident, but minimally detrimental, effects on the gut microbiota.