August 27, 2024 - Cláudia Marques, Ph.D., Binghamton University

Please note that the seminar begins at the 26:00 minute mark in the recording

Cláudia Marques, Ph.D.

Associate Professor

Department of Biological Sciences

Binghamton University

Effects of Metal Oxide Food Additive on a ‘Synthetic’ Small Intestine Microbiome

Abstract

A Western diet includes engineered nanoparticles (NP) on the order of 1012 to 1014 per day. These NP are present mostly in the form of metal oxides which are commonly used for their preservative, anticaking, and colorizing properties. Although they are widely used, currently not much is known on the effect of these NP on the gut microbiome, more specifically on the small intestine, where the food is processed. The overall human gut microbiome plays vital and wide-ranging roles in human health, immunity, and metabolic regulation. In our group we have developed a synthetic microbial community composed of Bifidobacterium bifidum, Lacticaseibacillus rhamnosus, Streptococcus salivarius, and Enterococcus faecalis which consist of four of the six main genera found in the upper gut. Once the community was established and reached a stable bacterial ratio, it was challenged with physiologically relevant concentrations of six of the most used NP in food processing and packaging - aluminum dioxide (Al2O3), iron oxide (Fe2O3), magnesium dioxide (MgO), silicon dioxide (SiO2), titanium dioxide (TiO2), and zinc oxide (ZnO). The NP challenge mimicked acute (4 hours) and chronic (24 hours) exposures. Microbial population was determined by qPCR to establish overall biomass and alterations of bacterial ratios. In addition, the effects of exposure to NP on bacterial SOS response was also quantified for the synthetic microbiota to establish whether NPs induce bacterial stress. In addition, to further mimic the small intestine, the established synthetic microbiome was transposed onto a mammalian small intestine model composed of Caco-2/HT-29 cells to develop a small intestine on a chip where the top open chamber houses the epithelial and bacterial cells (simulating the gut lumen), and the bottom chamber recirculates (simulating blood vessels). We were able to maintain the system with an intact monolayer for 96 hours and used it to assess nutrient transport of glucose and proteins. This novel small intestine model can relay information and significantly expand our knowledge on the effects of NP on gut microbiome, dysbiosis, nutrition, and disease.

Speaker Biography

Dr. Marques is currently an Associate Professor in the Department of Biological Sciences at Binghamton. Her research focus includes microbial communities, interspecies biofilms, microbial control, bacterial persister cells, and how the microorganisms interact with the host to cause infections or how they can be beneficial to the host. Current projects include: effect of gut microbiome on intestinal permeability and food adsorption recognition of persister cells by the host and their ability to initiate an infection, the influence of Staphylococcus aureus and Staphylococcus epidermidis on atopic dermatitis, infections of bronchial epithelial cells with dual-species biofilms of S. aureus and Pseudomonas aeruginosa, reversion of the bacterial persister cell state of P. aeruginosa and Staphylococcus aureus.