Effects of heat-killed Lactobacillus casei subsp. casei 327 intake on defecation in healthy volunteers: a randomized, double-blind, placebo-controlled, parallel-group study.

Lactobacillus casei subsp. casei 327 (L. casei 327) was isolated from brown rice. A preliminary study showed that intake of 50 mg of heat-killed L. casei 327 is effective in improving defecation. In this study, we conducted a randomized, double-blind, placebo-controlled, parallel-group trial to investigate the effect of intake of heat-killed L. casei 327 (25 mg: approximately 5 × 1010 bacteria) on defecation in healthy volunteers with relatively low defecation frequencies. We selected 104 healthy Japanese adults with relatively low defecation frequencies (approximately 3-5 times a week) by screening and pretrial tests. Subjects (n=52 in each group) were randomly given a tablet containing L. casei 327 (group A) or a placebo tablet (group P) daily for 2 weeks. After eliminating data for 9 subjects who met the exclusion criteria for efficacy analysis, data for 95 subjects were analyzed. The defecation frequency and number of defecation days during the intake period and their changes from the pretrial period were significantly higher in group A than in group P. The fecal volume during the intake period was higher in group A than group P, but the difference was not statistically significant. However, the change from the pretrial period was significantly higher in group A than in group P. There were no significant differences between groups in the values of fecal shape, color, odor, and feeling after defecation. These results suggested that intake of L. casei 327 improves defecation in healthy adults who have relatively low defecation frequencies.

Long-Term Diet Supplementation with Lactobacillus paracasei K71 Prevents Age-Related Cognitive Decline in Senescence-Accelerated Mouse Prone 8.

This study aimed to assess the suppressive effect of long-term diet supplementation with Lactobacillus strains on cognitive decline in the senescence-accelerated mouse prone 8 (SAMP8) model. For 43 weeks, fourteen-week-old female SAMP8 mice were fed a standard diet containing 0.05% (w/w) Lactobacillus casei subsp. casei 327 (L. 327) or Lactobacillusparacasei K71 (L. K71) derived from rice grains and sake lees, respectively. SAMP8 mice that were fed a L. K71-supplemented diet had better cognitive performance compared with the control and L. 327 groups in the Barnes maze and passive avoidance tests. An ELISA analysis revealed that the levels of serotonin were elevated in the serum and brain tissue of L. K71-fed mice. The protein expression levels of brain-derived neurotrophic factor (BDNF), cAMP response element binding protein (CREB), and phosphorylated CREB were evaluated using western blot. Long-term administration of L. K71 resulted in increased protein expression of BDNF and CREB phosphorylation in the hippocampus. These results suggest that prolonged intake of a diet supplemented with a Lactobacillus strain derived from sake lees may prevent age-dependent cognitive decline by upregulating BDNF expression in the hippocampus.

Effects of intake of Lactobacillus casei subsp. casei 327 on skin conditions: a randomized, double-blind, placebo-controlled, parallel-group study in women.

Lactic acid bacteria are gut flora that play key roles in intestinal homeostasis, which may affect a variety of physiological functions. Our preliminary double-blind, placebo-controlled, parallel-group trials have suggested that intake of heat-killed Lactobacillus casei subsp. casei 327 (designated L. K-1) is effective for improving skin conditions. The aim of this study was to confirm the effect of L. K-1 intake in a randomized, double-blind, placebo-controlled, parallel-group study in healthy female volunteers. Sixty-four subjects were allocated to either the placebo food group (group P, n=32) or active food group (group A, n=32), in which subjects consumed lactobacillus K-1 50 mg (approximately 1 × 1011 bacteria) daily for 8 weeks. After excluding subjects who declined to participate (n=1), violated restrictions (n=4), or were judged ineligible by the principal investigators (n=1), data obtained with 58 subjects (30 in group A and 28 in group P) were analyzed for efficacy by comparing differences from pretrial levels between the two groups. When the level of transepidermal water loss (TEWL) was measured at the arm, the level of TEWL at week 4 of the intake period was significantly lower in group A than group P (p=0.021), suggesting an improvement of skin barrier function. Analysis of skin condition questionnaire data revealed a significant reduction in skin flakiness on the face (week 4). No adverse events were associated with intake of the test foods. The safety of L. K-1 was also confirmed in an independent open-label trial in 11 healthy subjects who consumed excessive amounts of L. K-1 250 mg (approximately 5 × 1011 bacteria). Intake of L. K-1 may therefore be beneficial to skin condition improvement.

Randomized, double-blind, placebo-controlled, parallel-group study of the effect of Lactobacillus paracasei K71 intake on salivary release of secretory immunoglobulin A.

Lactobacillus paracasei K71 was shown to be effective in alleviating the severity of atopic dermatitis in a randomized controlled trial, and a preliminary open-label trial suggested that strain K71 intake enhanced secretory immunoglobulin A (sIgA) release in the saliva. This study investigated the effect of K71 on sIgA release in a randomized, double-blind, placebo-controlled, parallel-group trial. The trial included 62 Japanese subjects aged 20-64 years with relatively low rates of salivary sIgA release. Subjects (n=31 in each group) were randomly given a tablet containing 100 mg (approximately 2 × 1011 bacteria) of K71 or a placebo tablet daily for 12 weeks. After eliminating data for eight subjects (four in each group) who met the exclusion criteria for efficacy analysis, data for 54 subjects were analyzed. The change in the rate of salivary sIgA release 8 weeks after initiation of the study compared with baseline was significantly higher in the K71 tablet group (105.5 ± 119.0 µg/min) than in the placebo group (52.7 ± 62.6 µg/min; p=0.047). There were no adverse events associated with intake of tablets containing K71. The safety of intake of L. paracasei K71 was also confirmed in an independent open-label trial with 20 healthy subjects who consumed excessive amounts of K71-containing food. L. paracasei K71 intake may therefore have some benefits in promoting mucosal immune function.

Complementary effect of oral administration of Lactobacillus paracasei K71 on canine atopic dermatitis.

BACKGROUND: Atopic dermatitis is a common skin disease encountered in dogs. Glucocorticoids are commonly recommended for symptomatic therapy and well-tolerated adjunctive therapies may help to reduce the necessary dose and associated risks of chronic glucocorticoid use. HYPOTHESIS/OBJECTIVES: The purpose of this study was to evaluate the complementary efficacy of oral administration of Lactobacillus paracasei K71 in canine atopic dermatitis (cAD). ANIMALS: Forty one dogs with mild to moderate cAD were recruited by19 animal hospitals. METHODS: Dogs were assigned to receive either the investigational agent (K71 group; n = 20) or cetirizine hydrochloride (control group; n = 21). Previously prescribed medications were allowed to be continued during the 12 week trial. Dogs were assessed by the investigators using the cAD Extent and Severity Index (CADESI) and a medication scoring system. Pet owners assessed their dogs using a visual analog scale (VAS) and pruritus scores. RESULTS: The CADESI scores, VAS and pruritus scores in both groups at 12 weeks were improved compared with their baselines. The CADESI and pruritus scores in the K71 group were slightly lower than those in the control group and the reduction of medication scores in the K71 group was significantly lower compared with the control group (P < 0.05; Student's t-test). CONCLUSIONS AND CLINICAL IMPORTANCE: Oral administration of K71 can be useful in dogs with cAD as a complementary therapy, by providing a steroid-sparing effect.

Rice protein ameliorates the progression of diabetic nephropathy in Goto-Kakizaki rats with high-sucrose feeding.

The effect of rice protein (RP) on diabetic nephropathy in non-obese, spontaneous type 2 diabetic Goto-Kakizaki (GK) rats was investigated.GK rats at 7 weeks of age were fed 20% RP or casein (C) in standard or high-sucrose diets for 10 weeks. Plasma total cholesterol,TAG, alkaline phosphatase (ALP), adiponectin, creatinine and urinary albumin excretion (UAE) were measured and renal histology was evaluated. Compared with C, RP lowered plasma TAG and improved plasma adiponectin levels in GK rats fed the standard diet (P<0·05), and also lowered total cholesterol and ALP in high-sucrose-fed GK rats (P<0·05). RP markedly suppressed the sharp increase in UAE when GK rats were fed high-sucrose diets (P<0·05), and prevented glomerular mesangial matrix expansion in the deep renal cortex near the corticomedullary junction (P<0·05). These results strongly indicate that dietary RP can ameliorate the progression of diabetic nephropathy at an early stage compared with C.

Beneficial effect of a diet containing heat-killed Lactobacillus paracasei K71 on adult type atopic dermatitis.

The purpose of this study was to investigate the clinical effect of a supplementary diet containing heat-killed lactic acid bacterium Lactobacillus paracasei K71 (LAB diet) on adult patients with atopic dermatitis (AD). A randomized, double-blind, placebo-controlled study was conducted in 34 adult type AD subjects who were treated with conventional topical corticosteroid and tacrolimus. LAB diet or placebo was added over 12 weeks. The primary end-point was the clinical severity of AD which was evaluated by a severity scoring system proposed by the guideline of the Japanese Dermatological Association. The effect was also secondarily evaluated by itch scores of visual analog scales (VAS), quality-of-life (QOL) impairment scores of Skindex 16 and consumption amounts of topical therapeutics. Data on these four assessment variables were collected at baseline and at week 4, 8 and 12. Within the study population, the skin severity scores were significantly decreased from baseline at week 8 (P<0.05) and at week 12 (P<0.01) in the LAB diet group but not in the placebo group. Influence of LAB diet on itch scores or QOL impairment scores was not evident. The consumption of topical therapeutics in the placebo group was 1.9-times greater in total amount compared with the corresponding value in the LAB diet group during the intervention period, although there was no significant difference. No LAB diet- or placebo-related adverse events were observed. We concluded that the LAB diet may have some benefits as a complementary therapy for adult AD patients who are managed with the conventional treatment.

Improvement in the in vivo digestibility of rice protein by alkali extraction is due to structural changes in prolamin/protein body-I particle.

Rice prolamin, constituting type-I protein body (PB-I), is indigestible and causes deterioration of rice protein nutritional quality. In this study, the in vivo digestibility of rice protein isolates was investigated by tracing their intraluminal transit in the gastrointestinal (GI) tract of rats by western blotting and by observing the structures excreted in the feces by electron microscopy. Two types of rice protein isolates, produced by alkali extraction (AE-RP) and by starch degradation (SD-RP), were compared. The protein patterns in the isolates were similar, but their digestion in the GI-tract showed striking differences. In the AE-RP group, 13-kDa prolamin (13P) quickly disappeared in the lower GI tract and was not excreted in the feces. By contrast, in the SD-RP group, 13P accumulated massively and nearly intact PB-Is were excreted. These results indicate that the in vivo digestibility of prolamin can be improved by alkali extraction through structural changes to it.

Superiority of alkali-extracted rice protein in bioavailability to starch degraded rice protein comes from digestion of prolamin in growing rats.

The rice protein prepared from alkaline extraction (AE-RP) has high digestibility compared to that obtained from starch degradation (SD-RP) in in vitro digestion experiments, and alterations in the protein body (PB) structures were observed in AE-RP in the previous study. The improvement in the digestibility of AE-RP is probably a result of the structural change of PB. The present study was carried out to elucidate the superiority of AE-RP compared to SD-RP in bioavailability in growing rats. There were no major differences between AE-RP and SD-RP in polypeptide compositions according to SDS-PAGE and their amino acid compositions. The equivalent body weight gain and similar growth curves in both AE-RP and casein (control) groups were obtained during the feeding period of 28 d, and their values were significantly higher compared to the SD-RP group (p<0.05). The protein efficiency ratio (PER) of the SD-RP (1.73) group was significantly lower than those of the AE-RP (1.87) and casein (1.84) groups (p<0.05). The plasma lysine concentrations at the last stage of the feeding period in the AE-RP and SD-RP groups were approximate levels and were appreciably lower, compared to that of the casein group (p<0.001). Portal plasma amino acid concentrations were determined after single administration (4 g/kg) of two rice proteins in non-anaesthetized rats. All the amino acid concentrations in the 2 groups reached a maximum level at 30 min or 1 h and decreased to the pre-administration levels 6 h after the start of administration. The total amounts of three amino acids, leucine, valine and arginine, which appeared in the portal blood during the 6 h period after the start of administration of AE-RP, were higher than those of SD-RP (p<0.05). Furthermore, 13 kDa prolamin was detected with Western-blot analysis only in the feces of rats fed SD-RP. Consequently, these results indicate that the bioavailability of rice protein containing prolamin was improved by alkaline extraction.

Effects of rice proteins from two cultivars, Koshihikari and Shunyo, on cholesterol and triglyceride metabolism in growing and adult rats.

The effect and mechanism of two types of rice protein, one from regular japonica rice Koshihikari and another from rice cultivar Shunyo, with low glutelin and high prolamin content, on cholesterol and triglyceride metabolism were compared by feeding casein and soy protein to male Wistar strain rats 7 and 20 weeks old ad libitum for 2 weeks. The results in adult rats clearly indicated that both rice proteins had cholesterol-lowering effects in the plasma and the liver, comparable to soy protein, and the effects were accompanied with TG-lowering effects in the liver. Similar effects were also observed in growing rats when the diets were supplemented with cholesterol. The mechanism of the cholesterol-lowering effects by these rice proteins cannot be explained solely by fecal steroid excretion, but the results indicate that not only regular rice protein but also Shunyo rice protein possesses improving effects on lipid metabolism, especially in the adult period.

Production of rice protein by alkaline extraction improves its digestibility.

Rice seed endosperm has two types of protein bodies (PB). Type I protein body (PB-I) accumulates prolamin and is hard to digest, while type II protein body (PB-II) mainly consists of glutelin, an easily digestible protein. A simple method to process rice protein and improve its digestibility was tested from the viewpoint of its application to food manufacturing. Rice protein prepared by alkaline extraction followed by neutralization sedimentation (AE-RP) was compared with that prepared by starch degradation by alpha-amylase (SD-RP). The crude protein content of AE-RP and SD-RP was 84.7% and 78.2%, respectively. There were no major differences in protein composition among AE-RP, SD-RP and rice flour by SDS-PAGE, except 16 kDa polypeptide. With respect to amino acids, all the groups showed quite similar compositions, although cysteine and methionine were lower in AE-RP. In an in vitro digestion study with pepsin and pancreatin, both the SDS-PAGE analysis of protein pattern and the crude protein content of undigested residue clearly demonstrated that AE-RP has a higher digestibility than SD-RP. To find the cause of the difference in digestibility, the structural property of protein bodies by two production methods was compared using electron microscopy. PB-II of AE-RP was transformed into small, amorphous granules, while that of SD-RP was still kept partial protein body structures. PB-I of AE-RP kept its protein body structure, but produced double layers. From the finding that glutelin-gold was detected by immunochemistry not only in small, amorphous granules but also in PB-I, mainly the cortex layer, in AE-RP, it became clear that PB-I was swollen and fragile as a result of alkali treatment. These results strongly indicate that the improvement in digestibility of AE-RP is a result of the structural change of PB-I and -II caused by alkaline extraction.