"Determining the efficacy of E.Coli Nissle 1917 (Ala-Gln) as a probiotic malnutrition treatment in an animal model"
This study set out to determine the efficacy of in-situ production of Alanyl-Glutamine by nonpathogenic E.coli Nissle 1917 as a novel approach to preventing and treating diarrheal diseases and malnutrition. Diarrheal diseases account for two million yearly deaths and millions more disability-adjusted- ife-years (DALYs). It is a disease of poverty, striking those whose access to sanitation and drinking water is limited. The highest burden of disease is on young children, who account for nearly 90% of these deaths, and the long term health outcomes of children who survive chronic diarrhea are also damaged. These repeated incidences of diarrhea in the first two years of life can result in severe malnutrition and micronutrient deficiencies, which have well documented negative effects on long term physical and mental development. Separately, E.coli Nissle 1917 (EcN) and Ala-Gln are both proven therapies for diarrhea and malnutrition. EcN has been successfully used as a probiotic treatment for diarrheal and intestinal diseases for over 80 years in central Europe, where it is available over the counter. Recent studies show that EcN induces tight junction and epithelial barrier repair, restoring function to damage caused by disease or malnutrition. Ala-Gln has been shown to work in oral rehydration therapy (ORT), where it enhances water and electrolyte absorption by the small intestine. In this study, EcN was modified to synthesize and secrete Ala-Gln in the intestines. This would combine the barrier repair functions of the Nissle with the enhanced electrolyte absorption of the Ala-Gln, potentially providing an effective means of preventing and treating the ill-effects of diarrhea and malnutrition. An ampicillin resistance marker was also inserted. Malnourished adult mice were orally gavaged with the live cultures over a seven day period. Additionally, the mice received 0.3mg/mL ampicillin in their drinking water. Upon euthanizing, ileum samples were collected and streaked on 100μg/mL ampicillin plates. Unfortunately, ampicillin resistant flora appeared to already live in the guts of the mice. In a second mini study, 4 of 6 control mice (receiving no E.coli treatment) had ampicillin resistant bacteria in their guts. Since ampicillin resistance was the only marker for confirming colonization of the Nissle strain, this study was flawed. Other limitations include invasions of ants and potential contamination between cages. A modified version of this study using neonatal mice is being continued here at UVA.