Enhanced Immunostimulating Activity of Lactobacilli-Mimicking Materials by Controlling Size.

The design and synthesis of materials capable of activating the immune system in a safe manner is of great interest in immunology and related fields. Lactobacilli activate the innate immune system of a host when acting as probiotics. Here, we constructed lactobacilli-mimicking materials in which polysaccharide-peptidoglycan complexes (PS-PGs) derived from lactobacilli were covalently conjugated to the surfaces of polymeric microparticles with a wide variety of sizes, ranging from 200 nm to 3 µm. The artificial lactobacilli successfully stimulated macrophages without cytotoxicity. Importantly, we found that the size of artificial lactobacilli strongly influenced their immunostimulating activities, and that artificial lactobacilli of 1 µm exhibited 10-fold higher activity than natural lactobacilli. One major advantage of the artificial lactobacilli is facile control of size, which cannot be changed in natural lactobacilli. These findings provide new insights into the design of materials for immunology as well as the molecular biology of lactobacillus.

Synthesis and immunestimulating activity of lactobacilli-originated polysaccharide-polymeric microparticle conjugates.

The design and synthesis of biomaterials capable of activating the immune system are of interest in immunology-related fields because of their ability to tune up the immune defenses of the host. Lactobacilli are a major constituent of normal human indigenous flora, and some specific strains are known to activate the immune system of the host as probiotics. In this study, we first fabricated novel biohybrid materials in which lactobacilli (L. casei strain Shirota, LcS)-originated polysaccharide-peptidoglycan complexes (PS-PGs) are conjugated with polymeric microparticles (MPs). PS-PGs conjugated onto polymeric MPs surfaces bound its specific antibody, suggesting that PS-PGs kept their original molecular recognition ability. The PS-PGs-based hybrid MPs with an appropriate density of conjugated PS-PGs effectively induced high levels of IL-12 production from macrophages without cytotoxicity. These results suggest that LcS-originated PS-PGs could be available bio-originated materials for developing novel biomaterials capable of activating the immune system in a safe manner.

Identification of an enzyme system for daidzein-to-equol conversion in Slackia sp. strain NATTS.

An Escherichia coli library comprising 8,424 strains incorporating gene fragments of the equol-producing bacterium Slackia sp. strain NATTS was constructed and screened for E. coli strains having daidzein- and dihydrodaidzein (DHD)- metabolizing activity. We obtained 3 clones that functioned to convert daidzein to DHD and 2 clones that converted DHD to equol. We then sequenced the gene fragments inserted into plasmids contained by these 5 clones. All of the gene fragments were contiguous, encoding three open reading frames (ORF-1, -2, and -3). Analysis of E. coli strains containing an expression vector incorporating one of the orf-1, -2, or -3 genes revealed that (i) the protein encoded by orf-1 was involved in the conversion of cis/trans-tetrahydrodaidzein (cis/trans-THD) to equol, (ii) the protein encoded by orf-2 was involved in the conversion of DHD to cis/trans-THD, and (iii) the protein encoded by orf-3 was involved in the conversion of daidzein to DHD. ORF-1 had a primary amino acid structure similar to that of succinate dehydrogenase. ORF-2 was presumed to be an enzyme belonging to the short-chain dehydrogenase/reductase superfamily. ORF-3 was predicted to have 42% identity to the daidzein reductase of Lactococcus strain 20-92 and belonged to the NADH:flavin oxidoreductase family. These findings showed that the daidzein-to-equol conversion reaction in the Slackia sp. NATTS strain proceeds by the action of these three enzymes.

Isolation and characterization of the equol-producing bacterium Slackia sp. strain NATTS.

Several kinds of carbohydrates such as sorbose, adonitol, and melezitose were found to enhance equol production from daidzein in an in vitro human fecal culture. Sorbose, one of the most effective carbohydrates, was used as a carbohydrate source for isolating the NATTS strain, which was a Gram-positive, non-spore-forming rod bacterium with high ability to convert daidzein to equol isolated from the 7th maintenance culture. The strain was found to belong to the genus Slackia family Coriobacteriaceae by 16S rRNA sequence-based analysis, and the prevalence of the Slackia sp. in Japanese adults was examined by reverse transcription-quantitative PCR (RT-qPCR), which was found to be 40% at a mean population level of 10(6) cells per gram of feces.

A case of tubulinopathy presenting with porencephaly caused by a novel missense mutation in the TUBA1A gene.

BACKGROUND: Tubulinopathies include a wide spectrum of disorders ranging from abnormal ocular movement to severe brain malformations, and typically present as diffuse agyria or perisylvian pachygyria with microcephaly, agenesis of the corpus callosum, and cerebellar hypoplasia. They are caused by the dysfunction of tubulins encoded by tubulin-related genes, and the TUBA1A gene encoding alpha-1A tubulin is most frequently responsible for this clinical entity. Porencephaly is relatively rare among patients with the TUBA1A mutations. Mild case of tubulinopathy associated with porencephaly caused by a novel TUBA1A mutation. CASE REPORT: The patient, a 10-month-old girl, presented with gross motor delay at 4 months of age and convulsions at 7 months of age. Brain magnetic resonance imaging showed porencephaly, occipital polymicrogyria, hypoplasia of the corpus callosum, volume loss of the white matter, dysgenesis of anterior limbs of internal capsules, non-separative basal ganglia, cerebellar hypoplasia, and dysplastic brainstem. We identified a novel de novo heterozygous missense mutation in the TUBA1A gene, c.381C > A (p.Asp127Glu), by whole-exome sequencing. DISCUSSION: Microtubules composed of tubulins regulate not only neuronal migration but also cell division or axon guidance. Accordingly, tubulinopathy affects the cortical lamination, brain size, callosal formation, and white matter as seen in the present case. In contrast to the previously reported cases, the present case showed milder cortical dysgenesis with a rare manifestation of porencephaly. The genotype-phenotype correlation is still unclear, and this study expands the phenotypic range of tubulinopathy.

Relationship of serum levels and dietary intake of isoflavone, and the novel bacterium Slackia sp. strain NATTS with the risk of prostate cancer: a case-control study among Japanese men.

PURPOSE: Isoflavones may play a role in the prevention of hormone-related cancers. Equol is an isoflavone metabolized from daidzein in the presence of certain intestinal bacteria. Slackia sp. strain NATTS, a newly identified equol-producing bacterium, was recently isolated from human feces in Japan. We investigated the association of serum levels and dietary intake of isoflavones and Slackia sp. strain NATTS with the risk of prostate cancer in a case-control study among Japanese men. METHODS: Fifty-six patients with newly diagnosed prostate cancer and 56 hospital controls were enrolled in this study. Isoflavones were assessed by measurement of serum levels and administration of a food frequency questionnaire. Slackia sp. strain NATTS in feces was also measured. The odds ratios (ORs) and 95 % confidence intervals (CIs) for prostate cancer were then determined using a logistic regression model. RESULTS: The adjusted ORs for prostate cancer in comparison with the highest to lowest categories were 0.06 (95 % CI 0.02-0.24) for serum genistein, 0.18 (95 % CI 0.06-0.52) for daidzein, 0.16 (95 % CI 0.06-0.46) for glycitein, 0.52 (95 % CI 0.22-1.22) for equol, 0.86 (95 % CI 0.30-2.48) for dietary genistein, and 0.80 (95 % CI 0.28-2.28) for dietary daidzein. The adjusted OR for prostate cancer in comparison with values above versus below the median was 0.95 (95 % CI 0.42-2.16) for Slackia sp. strain NATTS. CONCLUSION: Our study findings suggest that high serum levels of genistein, daidzein, and glycitein are significantly associated with a decreased risk of prostate cancer among Japanese men.

Counts of Slackia sp. strain NATTS in intestinal flora are correlated to serum concentrations of equol both in prostate cancer cases and controls in Japanese men.

BACKGROUND: Isoflavones, which are included in soybeans, have been suggested to protect against prostate cancer. Equol, one of isoflavones, is an intestinally derived bacterial metabolite of daidzein. A newly identified equol-producing bacterium, Slackia sp. strain NATTS, with a high equol-producing activity was isolated from human feces in Japanese adults. Counts of Slackia sp. strain NATTS in intestinal flora have not been assessed with regard to prostate cancer risk. In this study, we investigated the association of serum isoflavones and counts of Slackia sp. strain NATTS with prostate cancer risk in a case-control study. MATERIALS AND METHODS: Concentrations of isoflavones and counts of Slackia sp. strain NATTS in feces were measured from 44 patients with prostate cancer and 28 hospital controls. The risk of prostate cancer was evaluated in terms of odds ratios (ORs) and 95% confidence intervals (CIs) by the logistic regression analysis. RESULTS: The detection proportions of Slackia sp. strain NATTS in cases and controls were 34.1% and 25.0%, respectively. Counts of Slackia sp. strain NATTS were significantly correlated with serum concentrations of equol both in cases and controls (Spearman correlation coefficients, rs=0.639 and rs=0.572, p<0.01, respectively). Serum concentrations of genistein, daidzein, glycitein, and equol were not significantly associated with risk of prostate cancer. CONCLUSIONS: This study found that counts of Slackia sp. strain NATTS correlated with serum concentrations of equol both in prostate cancer cases and controls, but serum isoflavone concentrations were not associated with risk of prostate cancer in our patients.

Effects of a probiotic fermented milk beverage containing Lactobacillus casei strain Shirota on defecation frequency, intestinal microbiota, and the intestinal environment of healthy individuals with soft stools.

The effects of drinking a fermented milk beverage that contains Lactobacillus casei strain Shirota (LcS) at 40 billion bacterial cells/bottle for 4 weeks (probiotics, 1 bottle/day) on defecation frequency, intestinal microbiota and the intestinal environment of healthy individuals with soft stools were evaluated. Thirty-four healthy adults who had soft stools were randomised into 2 groups, and the effects of a regular 4-week intake of probiotics were evaluated by a placebo-controlled, double-blind, parallel-group comparative design. Defecation frequency significantly decreased after the 4-week intake period compared with before the probiotic treatment. The stool quality significantly improved (hardened) compared to the placebo. Also, the water content of the stools was lower in the probiotic group than in the placebo group. Live LcS was recovered at 6.9 ± 1.3 and 7.2 ± 0.8 log(10) CFU per 1g of stool after 2 and 4 weeks, respectively, of probiotic treatment. The number of bifidobacteria in the stools also increased significantly compared with the level before starting the probiotics. The organic acid levels (total, acetic acid, propionic acid, and butyric acid) significantly increased compared with the level before intake in both the probiotic and placebo groups, but they returned to the original levels after the end of the intake period. These results suggest that probiotic fermented milk beverage has an intestine-conditioning effect by improving the frequency of defecation and stool quality and increasing the intrinsic bifidobacteria in healthy individuals with soft stool.