Author
Masaki Ito
Other affiliations: Tottori University, Keio University
Bio: Masaki Ito is an academic researcher from University of Tokyo. The author has contributed to research in topics: Mobile device & Arabidopsis. The author has an hindex of 15, co-authored 65 publications receiving 913 citations. Previous affiliations of Masaki Ito include Tottori University & Keio University.
Topics: Mobile device, Arabidopsis, Participatory sensing, Visualization, Gene
Papers published on a yearly basis
Papers
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TL;DR: A novel mechanism for the MU-mediated inhibition of HA synthesis involving the glucuronidation of MU by endogenous UGT resulting in a depletion of UDP-GlcUA is proposed.
249 citations
TL;DR: It is suggested that a part of the transgalactosylated disaccharides passes into the colon, inducing changes in the colonic microflora composition, hastening carbohydrate fermentation, and depressing amino acid fermentation in the human gut.
Abstract: The effects of transgalactosylated disaccharide (TD) intake on human fecal microflora and their metabolism were investigated in 12 Japanese males. TD is a mixture of sugars, galactosyl galactose, and galactosyl glucose, synthesized from lactose through the transgalactosylation reaction of Streptococcus thermophilus beta-galactosidase. Volunteers took 15 g of the test sugar daily for 6 days. The TD ingestion increased the number of bifidobacteria and lactobacilli, but decreased the number of Bacteroidaceae and Candida spp. in the feces. The ratio of bifidobacteria to total bacteria increased from 0.28 to 0.51. TD decreased the fecal concentrations of propionic acid, isobutyric acid, isovaleric acid, and valeric acid. This sugar also lowered the fecal pH, and the concentrations of fecal ammonia, p-cresol, and indole. Moreover, a positive correlation was found between the concentration of ammonia, and that of branched-chain fatty acids (isobutyric acid and isovaleric acid), p-cresol, and indole. All of these compounds are produced from amino acids through deamination by the intestinal bacteria. The depression of amino acid fermentation by intestinal bacteria may be involved in the reduction of fecal ammonia. These results suggest that a part of the transgalactosylated disaccharides passes into the colon, inducing changes in the colonic microflora composition, hastening carbohydrate fermentation, and depressing amino acid fermentation in the human gut.
111 citations
TL;DR: The effects of galactooligosaccharides intake on fecal microflora and their metabolism were investigated in healthy volunteers, in whom the numbers of indigenous bifidobacteria are comparatively low.
Abstract: The effects of galactooligosaccharides intake on fecal microflora and their metabolism were investigated in twelve healthy volunteers, in whom the numbers of indigenous bifidobacteria are comparatively low. The galactooligosaccharides ingestion increased the number of bifidobacteria, but remarkable changes of other organisms were not observed. This sugar also lowered fecal nitroreductase activity, the concentrations of indole and isovaleric acid.
104 citations
TL;DR: Two cDNA clones encoding the E1β and E2 subunits of BCKDH, respectively, from Arabidopsis thaliana are isolated, indicating that the cellular sugar level is likely responsible for the dark-induced expression of these genes.
51 citations
13 Sep 2014
TL;DR: An integrated framework to provide ubiquitous and accurate elevation measurement using smartphones is proposed and it is revealed that this system can provide elevation with an error less than 5 meters in 90 % of the cases and less than 3 meters in 75 % ofThe cases, which is sufficient for most practical applications.
Abstract: Accurate estimation of elevation is important for many location based services. Although, it is possible to obtain altitude from GPS, its accuracy is unreliable and applicable in outdoors only. It is possible to use barometers on smartphones to estimate elevation in both indoor and outdoor scenarios. To this end, we proposed an integrated framework to provide ubiquitous and accurate elevation measurement using smartphones. Experiments conducted in both indoor and outdoor with different geographical characteristics reveal that our system can provide elevation with an error less than 5 meters in 90 % of the cases and less than 3 meters in 75 % of the cases, which is sufficient for most practical applications.
49 citations
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TL;DR: The future use of prebiotics may allow species-level changes in the microbiota, an extrapolation into genera other than the bifidobacteria and lactobacilli, and allow preferential use in disease-prone areas of the body.
Abstract: Prebiotics are non-digestible (by the host) food ingredients that have a beneficial effect through their selective metabolism in the intestinal tract. Key to this is the specificity of microbial changes. The present paper reviews the concept in terms of three criteria: (a) resistance to gastric acidity, hydrolysis by mammalian enzymes and gastrointestinal absorption; (b) fermentation by intestinal microflora; (c) selective stimulation of the growth and/or activity of intestinal bacteria associated with health and wellbeing. The conclusion is that prebiotics that currently fulfil these three criteria are fructo-oligosaccharides, galacto-oligosaccharides and lactulose, although promise does exist with several other dietary carbohydrates. Given the range of food vehicles that may be fortified by prebiotics, their ability to confer positive microflora changes and the health aspects that may accrue, it is important that robust technologies to assay functionality are used. This would include a molecular-based approach to determine flora changes. The future use of prebiotics may allow species-level changes in the microbiota, an extrapolation into genera other than the bifidobacteria and lactobacilli, and allow preferential use in disease-prone areas of the body.
2,312 citations
TL;DR: The probiotic concept is confined to effects exerted by viable microorganisms but is applicable independent of the site of action and route of administration, and may include sites such as the oral cavity, the intestine, the vagina, and the skin.
1,418 citations
TL;DR: The develop-ment of functional foods for the gut is in its infancy and will be successful only if more fundamental research is done on digestive physiology, the gut microflora, immune system and mucosal function.
Abstract: The gut is an obvious target for the development of functional foods, acting as it does as the interface between diet and the metabolic events which sustain life. The key processes in digestive physiology which can be regulated by modifying diet are satiety, the rate and extent of macronutrient breakdown and absorption from the small bowel, sterol metabolism, the colonic microflora, fermentation, mucosal function and bowel habit, and the gut immune system. The intestinal microflora is the main focus of many current functional foods. Probiotics are foods which contain live bacteria which are beneficial to health whilst prebiotics, such as certain non-digestible oligosaccharides which selectively stimulate the growth of bifidobacteria in the colon, are already on the market. Their claimed benefits are to alleviate lactose maldigestion, increase resistance to invasion by pathogenic species of bacteria in the gut, stimulate the immune system and possibly protect against cancer. There are very few reports of well-designed human intervention studies with prebiotics as yet. Certain probiotic species have been shown to shorten the duration of rotavirus diarrhoea in children but much more work is needed on the mechanism of immunomodulation and of competitive exclusion and microflora modification. The development of functional foods for the gut is in its infancy and will be successful only if more fundamental research is done on digestive physiology, the gut microflora, immune system and mucosal function.
1,416 citations
TL;DR: A prebiotic is a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-being and health and the "dose argument" is not supported by the scientific data: it is misleading for consumers and should not be allowed.
Abstract: A prebiotic is "a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-being and health." Today, only 2 dietary nondigestible oligosaccharides fulfill all the criteria for prebiotic classification. The daily dose of the prebiotic is not a determinant of the prebiotic effect, which is mainly influenced by the number of bifidobacteria/g in feces before supplementation of the diet with the prebiotic begins. The ingested prebiotic stimulates the whole indigenous population of bifidobacteria to growth, and the larger that population, the larger is the number of new bacterial cells appearing in feces. The "dose argument" is thus not supported by the scientific data: it is misleading for consumers and should not be allowed. A prebiotic index is proposed, defined as "the increase in the absolute number of bifidobacteria expressed divided by the daily dose of prebiotic ingested."
1,353 citations
TL;DR: Natural product and natural product-derived compounds that are being evaluated in clinical trials or are in registration (as at 31st December 2007) have been reviewed, as well as natural products for which clinical trials have been halted or discontinued since 2005.
976 citations