Human immunodeficiency virus (HIV) infection is no longer a fatal condition, thanks to newer medications inhibiting the retrovirus, but a puzzling phenomenon has surfaced among these patients non-AIDS complications. Scientists at Case Western Reserve University School of Medicine have resolved the mystery with their discovery of the leaky gut as the offender. Bacterial products seep out of the colon, trigger inflammation throughout the body and set into motion the processes of cardiovascular, neurodegenerative, chronic kidney and metabolic diseases, and cancer. Their findings appear in an edition this summer of PLOS Pathogens.
"Because the space inside the colon (the lumen) contains the highest concentration of bacteria in the body, we provide evidence that bacterial products are leaking out of the colon into the bloodstream of these patients," said senior author, Alan D. Levine, PhD, professor of medicine, pharmacology, pathology, molecular biology and microbiology, and pediatrics, Case Western Reserve University School of Medicine. "The immune system responds by launching an attack on these bacterial products, activating inflammation throughout the body that never stops."
Bacteria can induce serious illness, but bacterial products are harmless remnants of dead bacteria. However, the immune system does not easily distinguish between live bacteria and bacterial products. Therefore, an immune attack is launched when bacterial products enter the bloodstream. In an HIV infection, tight junctions within the colon become the weak link providing an entryway for bacterial products to leak out.
Tight junctions are small, indented areas along the epithelial surface of the colon, something like the interior folds of a partially inflated accordion. Tight junctions form a barrier within the colon by sealing adjacent epithelial cells, and each tight junction seals the gut lumen (colon interior) from the colon exterior. Epithelial (or sur
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Case Western Reserve University