In experiment 1 of this study, the interleukin-12 (IL-12)-inducing ability of six Enterococcus strains was evaluated in comparison with that of five Lactobacillus strains using murine splenocytes. At the same time, the involvement of Toll-like receptor (TLR) ligands in IL-12-inducing ability was assessed using splenocytes from TLR2-, TLR4- and MyD88-deficient mice. Most Enterococcus strains, especially Enterococcus faecalis strain EC-12, exerted higher IL-12-inducing ability compared with the Lactobacillus strains evaluated. Almost the same amount of IL-12 protein was produced by all lactic acid bacteria strains in splenocytes from TLR2- and TLR4-deficient mice, whereas splenocytes from MyD88-deficient mice showed no IL-12 production against all bacteria evaluated. In experiment 2, the role of TLR7, 8 and 9 ligands of E. faecalis strain EC-12 in the induction of IL-12 production was evaluated using murine macrophage cell line J774.1. A drastic decrease in IL-12-inducing ability was observed when heat-killed E. faecalis strain EC-12 was treated with nuclease, particularly RNase. In addition, less than one-tenth of IL-12 was produced by heat-killed E. faecalis strain EC-12 when both TLR7 and 9 were antagonized. These facts indicate that the nucleic acids of E. faecalis strain EC-12, particularly its RNA, are the potent TLR7 and 9 ligands that induce IL-12 production from antigen-presenting cells.

Transcriptome analyses were conducted on the ileal mucosa of 14- to 35-day-old piglets to investigate postnatal gut development during suckling and postweaning. The transcriptome profiles of 14-day-old suckling piglets showed a considerably higher number of differentially expressed genes than did those of 21-, 28-, and 35-day olds, indicating an intensive gut development during the first 14–21 postnatal days. In addition, the analysis of biological pathways indicated that Chemotaxis Leucocyte chemotaxis was the most significantly affected pathway in suckling piglets between 14 and 21 days of age. Weaning negatively affected pathways associated with acquired immunity, but positively affected those associated with innate immunity. Interestingly, pathway Chemotaxis Leucocyte chemotaxis was found positively affected when comparing 14- and 21-day-old suckling piglets, but negatively affected in 28-day-old piglets weaned at 21 days of age, when compared with 28-day-old suckling piglets. Genes CXCL13, SLA-DOA (MHC class II), ICAM1, VAV1, and VCAM1 were involved in the pathway Chemotaxis Leukocyte chemotaxis and they were found to significantly change between 14- and 21-day-old suckling piglets and between groups of suckling and weaned piglets. The expression of these genes significantly declined after weaning at 14, 21, and 28 days of age. This decline indicated that CXCL13, SLA-DOA, ICAM1, VAV1, and VCAM1 may be involved in the development of Peyer’s patches (PP) because lower gene expression clearly corresponded with smaller areas of PP in the ileal mucosa of piglets. Moreover, weaning piglets prior to a period of intensive gut development, i.e., 14 days of age, caused significant adverse effects on the size of PP, which were not reverted even 14 days postweaning.

Several clinical studies have shown that isoflavones and Lactobacillus casei Shirota (LcS) have beneficial effects on skin condition and the gut microbiota, respectively. Thus, we investigated the effects of consecutive intake of fermented soymilk (FSM) with LcS on skin condition and the gut microbiota, as well as isoflavone bioavailability, in a randomised, double-blind, placebo-controlled trial as a pilot study. Sixty healthy premenopausal Japanese women received FSM containing a moderate level of isoflavone aglycones and a probiotic LcS, or soymilk (SM) containing neither of them, twice a day for 8 weeks. Skin condition was assessed by a subjective questionnaire for face and morphological analysis of the stratum corneum on the inner forearm. Faecal microbiota and urinary isoflavone were analysed by 16S rRNA gene amplicon sequencing and high-performance liquid chromatography tandem mass spectrometry, respectively. Both the FSM and SM groups had improved skin condition as assessed from scores of overall satisfaction, dryness, moisture, elasticity, coarseness, pigmentation and/or stratum corneum morphology, as well as significantly increased levels of urinary isoflavones during the intake period compared with the pre-intake period, although there were no significant differences between the two groups. There was a significant positive correlation between urinary isoflavone levels and skin questionnaire scores. In contrast, the relative abundance levels of Lactobacillaceae significantly increased and those of Bifidobacteriaceae tended to increase during the intake period compared with the pre-intake period. For the after-intake period they only decreased significantly in the FSM group. The levels of Enterobacteriaceae and Porphyromonadaceae significantly decreased during the intake period in the FSM group. These findings suggest that daily intake of FSM, as well as SM, provides health benefits that improve skin condition via increased levels of isoflavone absorption in the body, and that only FSM beneficially modifies the gut microbiota in premenopausal healthy women.

This study aimed to investigate the bioavailability of serum isoflavones after the intake of soymilk fermented by Lactobacillus casei strain Shirota containing 32.5% isoflavone aglycones (FSM) or placebo soymilk containing no isoflavone aglycones (SM). In a double-blind, placebo-controlled, single-dose, crossover trial, 7 healthy premenopausal Japanese women (mean age: 35.3 ± 11.0) consumed FSM or SM on day 1 and crossed over to the other soymilk after a 6-day washout period. Serum isoflavones in blood samples collected at 0, 1, 2, 3, 4, and 5 hr after intake were analyzed by liquid chromatography coupled with tandem mass spectrometry. The area under the curve (AUC) values for the serum concentrations of genistein and total isoflavones were significantly higher, by about 1.4-fold, up to 5 hr after FSM intake compared with SM intake (each p<0.05), and that of daidzein tended to be higher after FSM intake. In addition, AUC analysis of total isoflavones for individual subjects revealed that 5 out of 7 subjects had higher AUC values after FSM intake compared with SM intake and that the 2 remaining subjects had similar AUC values. These 2 subjects had higher AUC values after SM intake (mean, 2,502 ± 348) than those of the other subjects (mean, 1,158 ± 269). These results indicate that the bioavailability of isoflavones, especially genistein, is enhanced after the intake of FSM containing 32.5% isoflavone aglycones compared with intake of SM containing no isoflavone aglycones and that the enhancement is observed in healthy premenopausal Japanese women whose isoflavone absorption capacity is low after SM intake.

This study aimed to examine whether daily intake of citrus juice containing heat-killed Lactobacillus plantarum YIT 0132 (LP0132-fermented juice) alleviates symptoms of atopic dermatitis. This was a natural extension of our previous study in which LP0132 was shown to enhance IL-10 production in vitro and LP0132-fermented juice was found to alleviate symptoms and enhance quality of life (QOL) in patients with Japanese cedar pollinosis. In two open trials, Trial 1 and Trial 2, 32 and 18 adult patients with mild to moderate atopic dermatitis consumed LP0132-fermented juice for 8 weeks. Skin conditions and QOL were subjectively evaluated using Skindex-16 before intake of the juice (Pre-treatment), 8 weeks after starting intake (Treatment) and 8 weeks after termination of intake (Post-treatment). Blood parameters were also analyzed. Comparison of the Treatment and Post-treatment time points with the Pre-treatment time point revealed significant reductions in the Skindex-16 overall score and the 3 domain subscores (symptoms, emotions, and functioning domains) in both trials. Moreover, blood levels of eosinophil cationic protein (ECP), total immunoglobulin E (IgE) and specific IgEs for Japanese cedar and cypress pollen were significantly attenuated in Trial 2. The findings suggest that daily intake of citrus fermented juice containing heat-killed LP0132 has beneficial effects on symptoms and QOL in patients with mild to moderate atopic dermatitis due to an immunomodulatory effect via attenuation of IgE and ECP.