(541f) An Innovative Particulate Platform for Pre-Mortem Sampling Small Intestinal Microbiota

The gastrointestinal tract (GI) tract of humans and other vertebrates exhibits profound regional distinctions, highlighting the critical need for comprehensive analysis of the entire gut microbiota during sampling. However, currently, there is a lack of commercially available systems for non-invasively surveying the upper GI tract contents and existing alternatives often involve invasive procedures and/or post-mortem analysis. Addressing this current gap holds immense potential for reshaping the landscape of human gut microbiome research, facilitating longitudinal studies, and ushering in new frontiers in GI medicine with significant implications for diagnostics and therapeutics.
We have developed an innovative method involving a novel pH-sensitive biomolecular polymer that can favorably associate with bacteria in low pH conditions, such as those in the upper GI tract regions like the stomach, duodenum, and jejunum. Preliminary investigations indicate a favorable association between the sampling polymer and Gram-positive bacterial cells, as evidenced by complexation of fluorescently tagged sampling polymer with fluorophore-labeled Gram-positive cell membranes. Specifically, we can leverage this polymer by grafting it to magnetic particles as this allows for ready separation from the rest of the fecal matter. Since stool pH is known to be 5.5 - 6.5 for most of the small intestine before increasing to 7.4 - 7.5 near the terminal ileum, a system capable of transitioning between these pH values was used to target the capture of upper GI microbiota. Overall, this innovative polymer-conjugated magnetic particle-based approach holds promise for enabling comprehensive peri-mortem sampling and analysis of the upper GI tract microbiota non-invasively, which could significantly advance human gut health research.