2021/06/09
Keio University Faculty of Pharmacy
A research group led by Keio University and Meiji Holdings Co., Ltd. has revealed that the intake of amino acids, particularly glutamic acid, suppresses dehydration associated with bacterial infectious diarrhea by increasing an individual's water consumption. This research is the result of a research group led by Tatsuki Kimizuka (then a master's student at the Graduate School of Pharmaceutical Sciences, Keio University), Professor Yungi Kim of the Faculty of Pharmacy, and Meiji Holdings Co., Ltd.
Infectious gastroenteritis is a disease caused by intestinal infections from viruses, bacteria, and other pathogens. It is one of the world's most significant diseases, with high mortality and morbidity rates, especially among children in developing countries. Symptoms of infectious gastroenteritis include diarrhea, vomiting, nausea, abdominal pain, and fever, and it is known that its pathology varies depending on nutritional status. Therefore, it is conceivable that diet may affect clinical symptoms, but the actual details remain unclear.
In this study, using a lethal infectious diarrhea model in mice, we found that an amino acid diet dramatically improves the survival rate after infection with intestinal pathogenic bacteria. While the amino acid diet did not suppress the colonization of intestinal pathogenic bacteria in the gut or post-infection inflammation, it strongly suppressed dehydration associated with infectious diarrhea. It was found that an increase in water consumption was one of the factors contributing to the suppression of dehydration by this amino acid diet. Amino acid analysis and 16S rDNA analysis revealed that the intake of the amino acid diet increased glutamic acid concentrations in the blood and intestines and altered the gut microbiota. Consequently, when glutamic acid was orally administered to mice, an increase in water consumption was observed, and it was possible to prevent dehydration caused by bacterial infectious diarrhea.
From the above, it has become clear that the intake of amino acids, particularly glutamic acid, can reduce the risk of dehydration by increasing daily water consumption. Furthermore, it was also suggested that this increase in water consumption may be an effect mediated by changes in the gut microbiota. The results of this study suggest that dietary intervention with amino acids and improvement of the gut microbiota may be effective not only for dehydration due to infectious diarrhea but also for "hidden dehydration" in the elderly and infants, who are prone to insufficient body fluid levels, raising expectations for future practical applications. The results of this research were published in the online edition of the international academic journal "Nutrients" on May 31, 2021 (US Eastern Time).
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