Effects of molecular hydrogen-dissolved alkaline electrolyzed water on intestinal environment in mice

Increasing evidence indicates that molecular hydrogen-dissolved alkaline electrolyzed water (AEW) has various physiological activities such as antioxidative activity. Gut microbiota are deeply associated with our health through a symbiotic relationship. Recent reports have described that most gastrointestinal microbial species encode the genetic capacity to metabolize molecular hydrogen, meaning that molecular hydrogen might affect the gut microbial composition. Nevertheless, AEW effects on gut microbiota remain unknown. This study investigated AEW effects on the intestinal environment in mice, including microbial composition and short-chain fatty acid contents. After mice were administered AEW for 4 weeks, 16S rRNA gene sequencing analyses revealed their fecal microbiota profiles. Organic acid concentrations in cecal contents were measured using an HPLC system. Compared to the control group, AEW administration mice had significantly lower serum low-density lipoprotein cholesterol level and alanine aminotransferase activity. Organic acid concentrations of propionic, isobutyric, and isovaleric acids were higher in AEW-administered mice. Results of 16S rRNA gene sequencing analyses showed that the relative abundances of 20 taxa differed significantly in AEW-administered mice. Although the definitive role of gut microbes of AEW-administered mice remains unknown, our data demonstrate the possibility that AEW administration affects the gut microbial composition and that it has beneficial health effects in terms of cholesterol metabolism and liver protection. Higashimura Yasuki 1 Department of Food Science, Ishikawa Prefectural University, Nonoichi, Ishikawa; Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Kyoto Baba Yasunori 2 Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, Ishikawa Inoue Ryo 3 Laboratory of Animal Science, Department of Agricultural and Life Sciences, Kyoto Prefectural University, Kyoto Takagi Tomohisa 4 Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Kyoto Uchiyama Kazuhiko 5 Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Kyoto Mizushima Katsura 6 Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Kyoto Hirai Yasuko 7 Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Kyoto Ushiroda Chihiro 8 Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Kyoto Tanaka Yoshinori 9 Appliances Company, Panasonic Corporation, Shiga Naito Yuji 10 Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Kyoto Bajzer M, Seeley RJ. Physiology: obesity and gut flora. Nature. 2006;444:1009-1010. Shen J, Obin MS, Zhao L. The gut microbiota, obesity and insulin resistance. Mol Aspects Med. 2013;34:39-58. Yoshimoto S, Loo TM, Atarashi K, et al. Obesity-induced gut microbial metabolite promotes liver cancer through senescence secretome. Nature. 2013;499:97-101. Cummings JH, Macfarlane GT. The control and consequences of bacterial fermentation in the human colon. J Appl Bacteriol. 1991;70:443-459. Topping DL, Clifton PM. Short-chain fatty acids and human colonic function: roles of resistant starch and nonstarch polysaccharides. Physiol Rev. 2001;81:1031-1064. Kimura I, Inoue D, Maeda T, et al. Short-chain fatty acids and ketones directly regulate sympathetic nervous system via G protein-coupled receptor 41 (GPR41). Proc Natl Acad Sci USA. 2011;108:8030-8035. Kimura I, Ozawa K, Inoue D, et al. The gut microbiota suppresses insulin-mediated fat accumulation via the short-chain fatty acid receptor GPR43. Nat Commun. 2013;4:1829. Furusawa Y, Obata Y, Fukuda S, et al. Commensal microbe-derived butyrate induces the differentiation of colonic regulatory T cells. Nature. 2013;504:446-450. Koyama K, Tanaka Y, Saihara Y, Ando D, Goto Y, Katayama A. Effect of hydrogen saturated alkaline electrolyzed water on urinary oxidative stress makers after an acute severe exercise: a randomized controlled trial. Anti Aging Med. 2008;4:117-122. Fujita R, Tanaka Y, Saihara Y, Yamakita M, Ando D, Koyama K. Effect of molecular hydrogen saturated alkaline electrolyzed water on disuse muscle atrophy in gastrocnemius muscle. J Physiol Anthropol. 2011;30:195-201. Shimamura Y, Shinke M, Hiraishi M, Tsuchiya Y, Masuda S. The application of alkaline and acidic electrolyzed water in the sterilization of chicken breasts and beef liver. Food Sci Nutr. 2016;4:431-440. Wolf PG, Biswas A, Morales SE, Greening C, Gaskins HR. H2 metabolism is widespread and diverse among human colonic microbes. Gut Microbes. 2016;7:235-245. Tanaka Y. Structure and function of alkaline ionized water apparatus. J Funct Water. 2017;12:29-34. Ushida K, Sakata T. Effect of pH on oligosaccharide fermentation by porcine cecal digesta. Anim Sci Technol. 1998;69:100-107. Matsumoto M, Inoue R, Tsuruta T, Hara H, Yajima T. Long-term oral administration of cows' milk improves insulin sensitivity in rats fed a high-sucrose diet. Br J Nutr. 2009;102:1324-1333. Nishino K, Nishida A, Inoue R, et al. Analysis of endoscopic brush samples identified mucosa-associated dysbiosis in inflammatory bowel disease. J Gastroenterol. 2018;53:95-106. Caporaso JG, Kuczynski J, Stombaugh J, et al. QIIME allows analysis of high-throughput community sequencing data. Nat Methods. 2010;7:335-336. Edgar RC. Search and clustering orders of magnitude faster than BLAST. Bioinformatics. 2010;26:2460-2461. DeSantis TZ, Hugenholtz P, Larsen N, et al. Greengenes, a chimera-checked 16S rRNA gene database and workbench compatible with ARB. Appl Environ Microbiol. 2006;72:5069-5072. Al-Lahham SH, Peppelenbosch MP, Roelofsen H, Vonk RJ, Venema K. Biological effects of propionic acid in humans; metabolism, potential applications and underlying mechanisms. Biochim Biophys Acta. 2010;1801:1175-1183. Higashimura Y, Naito Y, Takagi T, Uchiyama K, Mizushima K, Yoshikawa T. Propionate promotes fatty acid oxidation through the up-regulation of peroxisome proliferator-activated receptor alpha in intestinal epithelial cells. J Nutr Sci Vitaminol (Tokyo). 2015;61:511-515. Hansen MK, McVey MJ, White RF, et al. Selective CETP inhibition and PPARalpha agonism increase HDL cholesterol and reduce LDL cholesterol in human ApoB100/human CETP transgenic mice. J Cardiovasc Pharmacol Ther. 2010;15:196-202. Sakamoto M, Takagaki A, Matsumoto K, Kato Y, Goto K, Benno Y. Butyricimonas synergistica gen. nov., sp. nov. and Butyricimonas virosa sp. nov., butyric acid-producing bacteria in the family 'Porphyromonadaceae' isolated from rat faeces. Int J Syst Evol Microbiol. 2009;59:1748-1753. Bolotin A, de Wouters T, Schnupf P, et al. Genome sequence of 'Candidatus Arthromitus' sp. Strain SFB-Mouse-NL, a commensal bacterium with a key eole in postnatal maturation of gut immune functions. Genome Announc. 2014;2:e00705-00714. Pinheiro I, Robinson L, Verhelst A, et al. A yeast fermentate improves gastrointestinal discomfort and constipation by modulation of the gut microbiome: results from a randomized double-blind placebo-controlled pilot trial. BMC Complement Altern Med. 2017;17:441. Ndongo S, Lagier JC, Fournier PE, Raoult D, Khelaifia S. 'Ihubacter massiliensis': a new bacterium isolated from the human gut. New Microbes New Infect. 2016;13:104-105. Xue J, Shang G, Tanaka Y, et al. Dose-dependent inhibition of gastric injury by hydrogen in alkaline electrolyzed drinking water.