BackgroundIt has been reported that the composition of human gut microbiota changes with age; however, few studies have used molecular techniques to investigate the long-term, sequential changes in gut microbiota composition. In this study, we investigated the sequential changes in gut microbiota composition in newborn to centenarian Japanese subjects.ResultsFecal samples from 367 healthy Japanese subjects between the ages of 0 and 104 years were analyzed by high-throughput sequencing of amplicons derived from the V3-V4 region of the 16S rRNA gene. Analysis based on bacterial co-abundance groups (CAGs) defined by Kendall correlations between genera revealed that certain transition types of microbiota were enriched in infants, adults, elderly individuals and both infant and elderly subjects. More positive correlations between the relative abundances of genera were observed in the elderly-associated CAGs compared with the infant- and adult-associated CAGs. Hierarchical Ward’s linkage clustering based on the abundance of genera indicated five clusters, with median (interquartile range) ages of 3 (0–35), 33 (24–45), 42 (32–62), 77 (36–84) and 94 (86–98) years. Subjects were predominantly clustered with their matched age; however, some of them fell into mismatched age clusters. Furthermore, clustering based on the proportion of transporters predicted by phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) showed that subjects were divided into two age-related groups, the adult-enriched and infant/elderly-enriched clusters. Notably, all the drug transporters based on Kyoto Encyclopedia of Genes and Genomes (KEGG) Orthology groups were found in the infant/elderly-enriched cluster.ConclusionOur results indicate some patterns and transition points in the compositional changes in gut microbiota with age. In addition, the transporter property prediction results suggest that nutrients in the gut might play an important role in changing the gut microbiota composition with age.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-016-0708-5) contains supplementary material, which is available to authorized users.

The aim of the present study was to evaluate the anti-obesity activity of a probiotic bifidobacterial strain in a mouse model with obesity induced by a high-fat diet. The mice were fed a high-fat diet supplemented with Bifidobacterium breve B-3 at 10(8) or 10(9) CFU/d for 8 weeks. B. breve B-3 supplementation dose-dependently suppressed the accumulation of body weight and epididymal fat, and improved the serum levels of total cholesterol, fasting glucose and insulin. The bifidobacterial counts in the caecal contents and feces were significantly increased with the B. breve B-3 administration. The expression of genes related to fat metabolism and insulin sensitivity in the gut and epididymal fat tissue was up-regulated by this administration. These results suggest that the use of B. breve B-3 would be effective in reducing the risk of obesity.

This study investigated the potential utilization of lacto-N-biose I (LNB) by individual strains of bifidobacteria. LNB is a building block for the human milk oligosaccharides, which have been suggested to be a factor for selective growth of bifidobacteria. A total of 208 strains comprising 10 species and 4 subspecies were analyzed for the presence of the galacto-N-biose/lacto-N-biose I phosphorylase (GLNBP) gene (lnpA) and examined for growth when LNB was used as the sole carbohydrate source. While all strains of Bifidobacterium longum subsp. longum, B. longum subsp. infantis, B. breve, and B. bifidum were able to grow on LNB, none of the strains of B. adolescentis, B. catenulatum, B. dentium, B. angulatum, B. animalis subsp. lactis, and B. thermophilum showed any growth. In addition, some strains of B. pseudocatenulatum, B. animalis subsp. animalis, and B. pseudolongum exhibited the ability to utilize LNB. With the exception for B. pseudocatenulatum, the presence of lnpA coincided with LNB utilization in almost all strains. These results indicate that bifidobacterial species, which are the predominant species found in infant intestines, are potential utilizers of LNB. These findings support the hypothesis that GLNBP plays a key role in the colonization of bifidobacteria in the infant intestine.Bifidobacteria are gram-positive anaerobic bacteria that naturally colonize the human intestinal tract and are believed to be beneficial to human health (21,30). Breastfeeding has been shown to be associated with an infant fecal microbiota dominated by bifidobacteria, whereas the fecal microbiota of infants who are consuming alternative diets has been described as being mixed and adult-like (12, 21). It has been suggested that the selective growth of bifidobacteria observed in breast-fed newborns is related to the oligosaccharides and other factors that are contained in human milk (human milk oligosaccharides [HMOs]) (3,4,10,11,16,17,34). Kitaoka et al. (15) have recently found that bifidobacteria possess a unique metabolic pathway that is specific for lacto-N-biose I (LNB; Gal␤1-3GlcNAc) and galacto-N-biose (GNB; Gal␤1-3GalNAc). LNB is a building block for the type 1 HMOs [such as lacto-N-tetraose

Antigen-specific immunoglobulin (Ig) A plays a major role in host defense against infections in gut mucosal tissue. Follicular helper T (Tfh) cells are located in germinal centers and promote IgA production via interactions with germinal center B cells. Several studies have demonstrated that some lactic acid bacteria (LAB) strains activate the host’s acquired immune system, inducing IgA secretion in the intestine. However, the precise molecular mechanisms underlying the effects of LAB on IgA production and Tfh cells are not fully resolved. Lactobacillus paracasei MCC1849 is a probiotic strain isolated from the intestine of a healthy adult. In this study, we investigated the effects of orally administered heat-killed MCC1849 on IgA production in the intestine and on Tfh cell induction in vivo. We found that orally administered MCC1849 induced antigen-specific IgA production in the small intestine, serum and lungs. We also observed that MCC1849 increased the proportion of IgA+ B cells and Tfh cells in Peyer’s patches (PPs). In addition, MCC1849 increased the gene expression of IL-12p40, IL-10, IL-21, STAT4 and Bcl-6 associated with Tfh cell differentiation. These results suggest that orally administered MCC1849 enhances antigen-specific IgA production and likely affects Tfh cell differentiation in PPs.

To better understand the mechanism of plastid differentiation from chloroplast to chromoplast, we examined proteome and plastid changes over four distinct developmental stages of ‘Micro-Tom’ fruit. Additionally, to discover more about the relationship between fruit color and plastid differentiation, we also analyzed and compared ‘Micro-Tom’ results with those from two other varieties, ‘Black’ and ‘White Beauty’. We confirmed that proteins related to photosynthesis remain through the orange maturity stage of ‘Micro-Tom’, and also learned that thylakoids no longer exist at this stage. These results suggest that at a minimum there are changes in plastid morphology occurring before all related proteins change. We also compared ‘Micro-Tom’ fruits with ‘Black’ and ‘White Beauty’ using two-dimensional gel electrophoresis. We found a decrease of CHRC (plastid-lipid-associated protein) and HrBP1 (harpin binding protein-1) in the ‘Black’ and ‘White Beauty’ varieties. CHRC is involved in carotenoid accumulation and stabilization. HrBP1 in Arabidopsis has a sequence similar to proteins in the PAP/fibrillin family. These proteins have characteristics and functions similar to lipocalin, an example of which is the transport of hydrophobic molecules. We detected spots of TIL (temperature-induced lipocalin) in 2D-PAGE results, however the number of spots and their isoelectric points differed between ‘Micro-Tom’ and ‘Black’/‘White Beauty’. Lipocalin has various functions including those related to environmental stress response, apoptosis induction, membrane formation and fixation, regulation of immune response, cell growth, and metabolism adjustment. Lipocalin related proteins such as TIL and HrBP1 could be related to the accumulation of carotenoids, fruit color and the differentiation of chromoplast.

A new protein crystallization method has been developed using a simplified counter‐diffusion method for optimizing crystallization condition. It is composed of only a single capillary, the gel in the silicon tube and the screw‐top test tube, which are readily available in the laboratory. The one capillary can continuously scan a wide range of crystallization conditions (combination of the concentrations of the precipitant and the protein) unless crystallization occurs, which means that it corresponds to many drops in the vapor‐diffusion method. The amount of the precipitant and the protein solutions can be much less than in conventional methods. In this study, lysozyme and alpha‐amylase were used as model proteins for demonstrating the efficiency of this method. In addition, one‐dimensional (1D) simulations of the crystal growth were performed based on the 1D diffusion model. The optimized conditions can be applied to the initial crystallization conditions for both other counter‐diffusion methods with the Granada Crystallization Box (GCB) and for the vapor‐diffusion method after some modification.

Plasma immunoreactive insulin-like growth factor-l/somatomedin C (IR-IGF-I) was determined in rats fed for 1 week on a protein-free diet, or diets containing gluten, gluten supplemented with lysine and threonine, maize-gluten meal (with arginine), maize-gluten meal (with arginine) supplemented with tryptophan and lysine, or casein. IR-IGF-1 concentration was higher in the arterial plasma of rats fed on a diet containing casein at 120 g/kg diet (4-8 U/ml) than in rats fed on a protein-free or a low-casein (SO g/kg diet) diet (15-2 U/ml). The plasma of rats fed on gluten or maize-gluten meal as the protein source showed intermediate values. However, giving a diet containing an amino acid mixture as recommended by the National Research Council (1978) but deprived of lysine or tryptophan did not affect significantly the plasma IR-IGF-1 concentration. Total IGF-1 concentration (which was measured immunologically after extraction of the plasma with acid-ethanol) was also lower in the rats fed on the protein-free diet than in those fed on the casein (120 g/kg diet) diet. The ratio IR-IGF-I: total IGF-1 was higher in the rats fed on the casein diet (120 g casein/kg diet) than in those fed on the protein-free diet. The results suggest an important influence of IR-IGF-1 or IR-IGF-1:total IGF-1 ratio on protein anabolism and nutrition. IR-IGF-1 and total IGF-1 were found in the fractions of molecular weights 40 kDa and 150 kDa after gel filtration of rat plasma. A larger amount of IGF-1 was recovered in the fraction of 150 kDa in the rats fed on the casein diet. '"I-IGF-I added to the plasma of rats fed on the protein-free diet was found mainly in the fraction of 40 kDa after gel-filtration. On the other hand, '251-IGF-1 added to the plasma of rats fed on the gluten or casein diets was mainly recovered in the free IGF-I fraction. The results suggest that 1GF-binding protein@) of molecular weight about 40 kDa was not saturated with IGF-1 in the rats fed on the protein-free diet. The results indicate the important role of IGF-1 and its binding proteins in the regulation of protein metabolism in rats.

It has been shown that the disruption of the α-subunit gene of heterotorimeric G-proteins (Gα) results in dwarf traits, the erection of leaves and the setting of small seeds in rice. These mutants are called d1. We have studied the expression profiles of the transcripts and translation products of rice Gα in ten alleles of d1 including five additional alleles newly identified. By RT-PCR, the transcripts of the Gα gene were detected in the all d1 alleles. By western blot, the Gα proteins were not detected in the plasma membrane fractions of the d1 alleles with the exception of d1-4. In d1-4, one amino acid change in the GTP-binding box A of the Gα protein was occurred and even in this case the Gα protein was only just detectable in the plasma membrane fraction. Given that the Gα protein did not accumulate in the plasma membrane fraction in d1-8 which has a deletion of just a single amino acid in the Gα protein, it is likely that a proper conformation of the Gα is necessary for accumulation of Gα protein in the plasma membrane. Nine alleles of d1 showed a severer phenotype whilst d1-4 exhibited a mild phenotype with respect to seed size and elongation pattern of internodes. As brassinosteroid signaling was known to be partially impaired in d1s, the sensitivity to 24-epibrassinolide (24-epiBL) was compared among d1 alleles in a T65 genetic background. Only d1-4 showed responses similar to wild type rice. The results show that the d1-4 mutant is a mild allele in terms of the phenotype and mild hyposensitivity to the exogenously applied 24-epiBL.