NutriClayZn binds aflatoxin B1 and suppresses pathogenic, antimicrobial resistant bacteria across the food supply chain

Authors: JACKSON, STEVEN - TEXAS A&M UNIVERSITY; ANDREWS, KATHLEEN - Kate; DROLESKEY, ROBERT - Bob; BANZ, WILLIAM - SOUTHERN ILLINOIS UNIVERSITY; APGAR, GARY - SOUTHERN ILLINOIS UNIVERSITY; RIVENBARK, KELLY - TEXAS A&M UNIVERSITY; WANG, MEICHEN - TEXAS A&M UNIVERSITY; ANDERSON, ROBIN; HARVEY, ROGER; PHILLIPS, TIMOTHY - TEXAS A&M UNIVERSITY

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/13/2025
Publication Date: 3/18/2025
Citation: Jackson, S.J., Andrews, K., Droleskey, R.E., Banz, W.J., Apgar, G.A., Rivenbark, K.J., Wang, M., Anderson, R.C., Harvey, R.B., Phillips, T.D. 2025. NutriClayZn binds aflatoxin B1 and suppresses pathogenic, antimicrobial resistant bacteria across the food supply chain. Journal of Food Science. 88(5). Article 100486. https://doi.org/10.1016/j.jfp.2025.100486.
DOI: https://doi.org/10.1016/j.jfp.2025.100486

Interpretive Summary: NutriClay and zinc oxide have traditionally been used as a feed additive to control reduced microbiological toxins produced in feed and control harmful fungi and bacteria thereby supporting the health and growth of farm animals. Moreover, some human populations such as those deployed in military situations are at high risk for contracting bacterial diarrhea from eating contaminated food or drinking contaminated water. However, the current industry practice of feeding zinc oxide to food animals at levels above and beyond the nutritional requirement is under regulatory scrutiny due to concerns of high amounts of zinc being excreted with manure into the environment. Consequently, acceptable alternative ways of feeding zinc oxide are sought to retain its bacterial control properties but with lower amounts of zinc being released to the environment. This experiment tested a new product, called NutriClayZn, that combines NutroClay with zinc oxide, the latter at concentrations much lower than when fed alone. This new product significantly inhibited the growth of bacterial pathogens such as Salmonella typhimurium, Staphylococcus aureus and Escherichia coli while retaining the toxin-removing capacity of the clay component. These findings suggest that NutriClayZn could serve as a dual-purpose dietary substance, binding microbiological toxins and suppressing the growth of pathogenic bacteria that can compromise the food supply. Ultimately, this research will provide an alternative strategy to safely feed NutriClay and zinc oxide thereby helping farmers and ranchers continue to produce safe and wholesome foods for the American consumer.

Technical Abstract: Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli represent foodborne pathogens that can trigger diarrhea and diminish weight gains in livestock, as well as cause gastroenteritis in humans. Although prophylactic antibiotics have been used historically on the farm to limit bacterial pathogens and promote animal growth, this practice may also foster antimicrobial resistant (AMR) strains of bacteria and deplete our arsenal of effective antibiotic therapies. Incorporation of free-chemical zinc oxide (ZnO) into animal feed, at doses far above nutritional requirements, has largely replaced prophylactic antibiotics; however, environmental concerns are mounting around unabsorbed zinc (excreted in feces) impacting soil microbes and thereby contributing to the AMR threat. Here, NutriClayZn is introduced as a novel analogue of montmorillonite (MMT) clay with potent efficacy against foodborne bacterial pathogens and slow release of low concentrations of zinc. Bacterial propagation was assessed in culture experiments using NutriClayZn dosages aligned with current dietary MMT clay practices for the control of aflatoxin in production animals. Zinc release was quantified by inductively coupled plasma mass spectrometry. Significant (p<0.05) growth reduction of Salmonella typhimurium was observed following NutriClayZn exposures releasing less zinc than that contained within free-chemical ZnO positive controls. Moreover, NutriClayZn clearly displayed robust, dose-dependent efficacy against AMR strains of both Staphylococcus aureus and Escherichia coli O157:H7, while binding aflatoxin B1 with kinetics similar to its parent MMT clay. These findings suggest that NutriClayZn could serve as a dual-purpose dietary substance, binding aflatoxin B1 and suppressing enterotoxigenic AMR bacteria that can compromise the food supply.