During stress, opportunistic bacteria break through intestinal barriers. This study evaluated the ability of a high-molecular-weight (HMW) polyethylene glycol to protect the intestinal epithelium against Pseudomonas aeruginosa. An in vitro study had already shown that a polyethylene glycol 15-20 compound (PEG 15-20) protected cultured cells. Thus, a mouse model of gut-derived sepsis was used to test in vivo capabilities. The mice had 30% of their livers removed surgically, and a solution of PEG 15-20 was injected into the cecum. A solution of P. aeruginosa was also introduced into the cecum. The PEG 15-20 protected the mice against lethal sepsis due to P. aeruginosa. One of the functions of the intestinal mucus is to cause the bacteria to clump and to stop colonization and invasion of the intestinal epithelium. The PEG 15-20 affected the clumping pattern of the bacteria and seemed to prevent the P. aeruginosa from coming near the intestinal epithelium.
COMMENTARY: Most nosocomial infections can be reduced or eliminated by simple procedures such as hand washing, yet they persist, perhaps because of the frenetic pace of medicine. How many of our readers can honestly say that they thoroughly wash their hands after seeing every patient? Endogenous infections are another and equally serious problem. The intestine has been described as a cross between a sewer and a brewery: The gut does not produce alcohol to any great extent but its teeming microbes are important to the health of the host in a spectrum of ways. In the healthy patient the contents of the intestinal "sewer" are prevented from being absorbed by the intestinal mucosal barrier, a complex physicochemical combination of mucus, complex chemicals, and antibodies. In sepsis, shock, trauma, and a variety of severe and chronic diseases this barrier is disrupted to allow translocation of bacteria, bacterial toxins, and other luminal contents into the submucosa and from there into the systemic circulation. Many critically ill patients thus die from their own absorbed bacteria. In this paper the authors provide a glimpse into the future: it may be possible to preserve the physical portion of the barrier by simple replacement with HMW PEG. If these observations hold true in vivo and later, in clinical trials, we will witness another significant decrease in morbidity and mortality of hospitalized patients. Meanwhile there is no substitute for hand washing and common sense.
