Influence of dietary fiber on microbial growth in vitro and bacterial translocation after burn injury in mice

Translocation of enteric bacteria from the gut to the mesenteric lymph nodes and beyond can cause life-threatening infection and multiple-organ failure in immunocompromised and traumatized patients. One of the conditions that promotes bacterial translocation is disruption of the normal gut flora, which results in bacterial overgrowth. In vitro methods were used to determine whether the fibers pectin, cellulose, chitosan, kaolin, lignin, or soy had bactericidal properties. Our results indicated that only chitosan and lignin significantly reduce microbial growth in vitro. A burned mouse model (20% total-body surface area) was used to study the effects of dietary lignin, cellulose, pectin, and chitosan on burn-induced bacterial translocation. Animals were fed a standard mouse diet containing no fiber, pectin, cellulose, lignin, or chitosan (10% of diet) for 14 days ad libitum. On day 14, all animals were burned. Four hours later the animals were killed and the mesenteric lymph nodes, spleen, liver, and cecum were aseptically harvested for determination of quantitative aerobic microbial growth. The animals which received chitosan, and lignin to a lesser extent, added to their diet had significantly lower levels of bacteria in the cecum, mesenteric lymph nodes, and liver. We suggest that addition of chitosan and possibly lignin to the diet may reduce the amount of bacterial translocation after burn injury, presumably by reducing the bacterial population of the cecum.