Scientists have created a groundbreaking technology that allows for the efficient separation of a specific group of gut bacteria from fecal samples, which are recognized by IgA antibodies. These ‘IgA-coated’ bacteria are linked to various diseases, and this innovative technology could help uncover how these relationships work, potentially leading to new treatment options.
Researchers at UMC Utrecht have invented a method that efficiently isolates a distinct group of gut bacteria found in fecal samples, specifically those identified by IgA antibodies. These ‘IgA-coated’ bacteria are linked to a variety of diseases, and this new technology may help in understanding the underlying mechanisms behind these associations, paving the way for innovative therapeutic approaches.
The gut microbiota, which consists of the vast array of microorganisms residing in our intestines, plays a vital role in guiding our immune system’s response to external threats. Consequently, it is essential for how our bodies react to different diseases. Antibodies are critical in mediating interactions between immune cells and microbes, with immunoglobulin A (IgA) being the most prevalent antibody type in the intestine. Once released, IgA identifies and binds to particular gut bacteria, with healthy individuals having approximately 35 percent of their gut bacteria coated in IgA.
Function of IgA-coated bacteria
In contrast, individuals with intestinal inflammatory conditions exhibit a higher percentage of IgA-coated bacteria, and changes to this subset’s composition have been noted in disorders such as allergies, asthma, irritable bowel syndrome, multiple sclerosis, and inflammatory bowel disease (IBD). While connections have been established between these microbes and the diseases mentioned, the specific biological roles of IgA-coated bacteria in both health and illness remain largely unexplored, as do the underlying mechanisms. Insight into these factors is crucial for devising strategies to combat these diseases. Unfortunately, current methods for studying IgA-coated bacteria are inefficient, slow, and costly.
Isolating IgA-coated bacteria
This prompted microbiologist Marcel de Zoete, PhD, and gastroenterologist Prof. Bas Oldenburg, MD PhD, at UMC Utrecht to develop a technology that enables quicker and more effective isolation of IgA-coated bacteria from human fecal samples. Their approach involved using tiny magnetic beads to attach to the IgA antibodies present on the bacteria. When the bacteria are exposed to a magnet, the IgA-coated bacteria are drawn in, allowing for the easy washing away of all other bacteria.
While this new method offers more efficient and high-throughput identification and isolation of IgA-coated bacteria, how does it compare to traditional techniques? Extensive control experiments conducted by post-doctoral researcher Merel Van Gogh, PhD (Department of Medical Microbiology), and PhD candidate Jonas Louwers, MD (Department of Gastroenterology & Center for Translational Immunology), demonstrated that this innovative method, termed next-generation IgA-SEQ, retains similar qualitative results as traditional methods but provides several benefits, including faster analysis of large sample sizes and high-quality sequencing of total bacterial DNA.
Significant contribution
Principal investigator Marcel de Zoete stated, “Next-generation IgA-SEQ is a significant addition to our scientific toolkit that can enhance our understanding of the role played by IgA-coated bacteria in health and disease. For instance, we can now identify specific immunostimulatory bacterial strains linked to the worsening or easing of IBD symptoms. Utilizing this technology will improve our comprehension of the microbiota’s role in both intestinal and systemic inflammatory disorders and could lead to new treatment avenues in the future.”
