Supportive Role of Probiotic Strains in Protecting Rats from Ovariectomy-Induced Cortical Bone Loss

Osteoporosis is a major health problem that occurs as a result of an imbalance between bone formation and bone resorption. Different approaches have been established for treating osteoporosis. Recently, because of their health benefits and also low adverse reaction, probiotics have been receiving considerable attention. In this study, we compared the effectiveness of five probiotic strains, Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei, Bifidobacterium longum, and Bacillus coagulans, in protecting rats from ovariectomized (OVX)-induced bone loss. Forty-nine adult female Sprague-Dawley rats were allocated into seven groups as follows: group 1, control; group 2, OVX; group 3, OVX + Lactobacillus acidophilus; group 4, OVX + Lactobacillus casei; group 5, OVX + Bacillus coagulans; group 6, OVX + Bifidobacterium longum; and group 7, OVX + Lactobacillus reuteri. Probiotics were fed to OVX groups at the concentration of (1 × 10⁹ CFU/ml/day) for 4 weeks. Then, biochemical parameters, including vitamin D, calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP), were assessed. Dual-energy X-ray absorptiometry (DEXA) scans were used that assess bone mineral density (BMD), bone marrow concentration (BMC), and area of global, femur, spine, and tibia. Lactobacillus acidophilus and Lactobacillus casei significantly increased Ca and ALP and decreased P in treated groups. Lactobacillus casei, Lactobacillus reuteri, and Bifidobacterium longum increased vitamin D significantly. Lactobacillus acidophilus and Lactobacillus casei indicated the most effects on BMD. In terms of BMC, and bone area, Lactobacillus acidophilus, Lactobacillus reuteri, and Lactobacillus casei demonstrated the significant enhancement in OVX groups treated with. Among the probiotics used in this study, Lactobacillus acidophilus and Lactobacillus casei showed the most effects in terms of BMD, BMC, bone area, and biochemical parameters. It seems that probiotics effects on bone health are strain dependent, but further studies should be done to prove these findings.

     

Protective Effect of the Intracellular Content from Potential Probiotic Bacteria against Oxidative Damage Induced by Acrylamide in Human Erythrocytes

The aim of this study was to assess the protective effect of the intracellular content obtained from potential probiotic bacteria against acrylamide-induced oxidative damage in human erythrocytes. First, the antioxidant properties of 12 potential probiotic strains was evaluated. Two commercial probiotic bacteria were included as reference strains, namely, Lactobacillus casei Shirota and Lactobacillus paracasei 431. Data showed that the intracellular content from four strains, i.e., Lactobacillus fermentum J10, Lactobacillus pentosus J24 and J26, and Lactobacillus pentosus J27, showed higher (P < 0.05) antioxidant capacity in most methods used. Thereafter, the intracellular content of such pre-selected strains was able to prevent the disturbance of the antioxidant system of human erythrocytes exposed to acrylamide, thereby reducing cell disruption and eryptosis development (P < 0.05). Additionally, the degree of oxidative stress in erythrocytes exposed to acrylamide was significantly (P < 0.05) reduced to levels similar to the basal conditions when the intracellular content of Lact. fermentum J10, Lact. pentosus J27, and Lact. paracasei 431 were employed. Hence, our findings suggest that the intracellular contents of specific Lactobacillus strains represent a potential source of metabolites with antioxidant properties that may help reduce the oxidative stress induced by acrylamide in human erythrocytes.

     

In Silico Prediction and In Vitro Assessment of Multifunctional Properties of Postbiotics Obtained From Two Probiotic Bacteria

In this study, a global metabolite profile using Raman spectroscopy analysis was obtained in order to predict, by an in silico prediction of activity spectra for substance approach, the bioactivities of the intracellular content (IC) and cell wall (CW) fractions obtained from Lactobacillus casei CRL 431 and Bacillus coagulans GBI-30 strains. Additionally, multifunctional in vitro bioactivity of IC and CW fractions was also assessed. The metabolite profile revealed a variety of compounds (fatty acids, amino acids, coenzyme, protein, amino sugars), with significant probable activities (Pa > 0.7) as immune-stimulant, anti-inflammatory, neuroprotective, antiproliferative, immunomodulator, and antineoplastic, among others. Moreover, in vitro assays exhibited that both IC and CW fractions presented angiotensin-converting enzyme–inhibitory (> 90%), chelating (> 79%), and antioxidant (ca. 22–57 cellular antioxidant activity units) activities. Our findings based on in silico and in vitro analyses suggest that L. casei CRL 431 and B. coagulans GBI-30 strains appear to be promising sources of postbiotics and may impart health benefits by their multifunctional properties.

     

Improved Viability of Microencapsulated Probiotics in a Freeze-Dried Banana Powder During Storage and Under Simulated Gastrointestinal Tract

Freeze-dried banana powder represents an ideal source of nutrients and has not yet been used for probiotic incorporation. In this study, microencapsulation by freeze drying of probiotics Lactobacillus acidophilus and Lactobacillus casei was made using whey protein isolate (WPI), fructooligosaccharides (FOS), and their combination (WPI + FOS) at ratio (1:1). Higher encapsulation yield was found for (WPI + FOS) microspheres (98%). Further, microcapsules of (WPI + FOS) were used to produce a freeze-dried banana powder which was analyzed for bacterial viability under simulated gastrointestinal fluid (SGIF), stability during storage at 4 °C and 25 °C, and chemical and sensory properties. Results revealed that (WPI + FOS) microcapsules significantly increased bacteria stability in the product over 30 days of storage at 4 °C averaging (≥ 8.57 log CFU/g) for L. acidophilus and (≥ 7.61 log CFU/g) for L. Casei as compared to free cells. Bacteria encapsulated in microspheres (WPI + FOS) were not significantly affected by the SGIF, remaining stable up to 7.05 ± 0.1 log CFU/g for L.acidophilus and 5.48 ± 0.1 log CFU/g for L.casei after 90 min of incubation at pH 2 compared to free cells which showed minimal survival. Overall, encapsulated probiotics enriched freeze-dried banana powders received good sensory scores; they can therefore serve as safe probiotics food carriers.

     

The Effects of Probiotic Supplementation on Genetic and Metabolic Profiles in Patients with Gestational Diabetes Mellitus: a Randomized,Double-Blind,Placebo-Controlled Trial

This study was carried out to evaluate the effects of probiotic supplementation on genetic and metabolic profiles in patients with gestational diabetes mellitus (GDM) who were not on oral hypoglycemic agents. This randomized, double-blind, placebo-controlled clinical trial was conducted in 48 patients with GDM. Participants were randomly divided into two groups to intake either probiotic capsule containing Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum, Lactobacillus fermentum (2 × 10⁹ CFU/g each) (n = 24) or placebo (n = 24) for 6 weeks. Probiotic intake upregulated peroxisome proliferator-activated receptor gamma (P = 0.01), transforming growth factor beta (P = 0.002) and vascular endothelial growth factor (P = 0.006), and downregulated gene expression of tumor necrosis factor alpha (P = 0.03) in peripheral blood mononuclear cells of subjects with GDM. In addition, probiotic supplementation significantly decreased fasting plasma glucose (β, − 3.43 mg/dL; 95% CI, − 6.48, − 0.38; P = 0.02), serum insulin levels (β, − 2.29 μIU/mL; 95% CI, − 3.60, − 0.99; P = 0.001), and insulin resistance (β, − 0.67; 95% CI, − 1.05, − 0.29; P = 0.001) and significantly increased insulin sensitivity (β, 0.009; 95% CI, 0.004, 0.01; P = 0.001) compared with the placebo. Additionally, consuming probiotic significantly decreased triglycerides (P = 0.02), VLDL-cholesterol (P = 0.02), and total-/HDL-cholesterol ratio (P = 0.006) and significantly increased HDL-cholesterol levels (P = 0.03) compared with the placebo. Finally, probiotic administration led to a significant reduction in plasma malondialdehyde (P < 0.001), and a significant elevation in plasma nitric oxide (P = 0.01) and total antioxidant capacity (P = 0.01) was observed compared with the placebo. Overall, probiotic supplementation for 6 weeks to patients with GDM had beneficial effects on gene expression related to insulin and inflammation, glycemic control, few lipid profiles, inflammatory markers, and oxidative stress.

     

Characterization,the Antioxidant and Antimicrobial Activity of Exopolysaccharide Isolated from Poultry Origin Lactobacilli

The natural antioxidant agent is urgently needed to prevent the negative effects of newly generated free radicals and chronic disorders. Recently, the microbial exopolysaccharide (EPS) is currently used as a potential biopolymer due to its unique biological characteristics. In this study, the biological potential was carried out on the EPSs produced by Lactobacillus reuteri SHA101 (EPS-lr) and Lactobacillus vaginalis SHA110 (EPS-lvg) isolated from gut cecum samples of healthy poultry birds (hen). As results, the EPS-lr and EPS-lvg showed the emulsifying activity of 37.8 ± 1.6% and 27.8 ± 0.5% after the 360 h, respectively. The scanning electron microscopy analysis of EPS-lr and EPS-lvg demonstrated a smooth surface with a compact structure. The both EPSs exhibited strong antibacterial activity against E. coli and Salmonella typhimurium in vitro. In additions, at 4 mg/mL concentration, the EPS-lr and EPS-lvg samples showed potent antioxidant activity regarding hydroxyl radical DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, superoxide anion radical and reducing power at OD_700 nm. Furthermore, the EPS-lr and EPS-lvg (600 μg/mL) possessed antitumor activity against colon cancer (Caco-2) cell after 72 h. The results suggested that these EPSs would have great potential in the application of antitumor and antioxidant foods, biomedicine, and pharmaceutics.

     

A randomized,double-blind,placebo-controlled,clinical trial on probiotic soy milk and soy milk: effects on epigenetics and oxidative stress in patients with type II diabetes

This clinical trial aimed to discover the effects of probiotic soy milk and soy milk on MLH1 and MSH2 promoter methylation, and oxidative stress among type II diabetic patients. Forty patients with type II diabetes mellitus aged 35–68 years were assigned to two groups in this randomized, double-blind, controlled clinical trial. Patients in the intervention group consumed 200 ml/day of probiotic soy milk containing Lactobacillus plantarum A7, while those in the control group consumed 200 ml/d of conventional soy milk for 8 weeks. Fasting blood samples, anthropometric measurements, and 24-h dietary recalls were collected at the baseline and at the end of the study, respectively. Probiotic soy milk significantly decreased promoter methylation in proximal and distal MLH1 promoter region (P < 0.01 and P < 0.0001, respectively) compared with the baseline values, while plasma concentration of 8-hydroxy-2′-deoxyguanosine (8-OHdG) decreased significantly compared with soy milk (P < 0.05). In addition, a significant increase in superoxide dismutase (SOD) activity was observed in probiotic soy milk group compared with baseline value (P < 0.01). There were no significant changes from baseline in the promoter methylation of MSH2 within either group (P > 0.05). The consumption of probiotic soy milk improved antioxidant status in type II diabetic patients and may decrease promoter methylation among these patients, indicating that probiotic soy milk is a promising agent for diabetes management.

Electronic supplementary material

The online version of this article (doi:10.1007/s12263-015-0503-1) contains supplementary material, which is available to authorized users.     

Production of lactic acid from date juice extract with free cells of single and mixed cultures of Lactobacillus casei and Lactococcus lactis

The production of lactic acid from date juice by single and mixed cultures of Lactobacillus casei and Lactococcus lactis was investigated. In the present conditions, the highest concentration of lactic acid (60.3 g l⁻¹) was obtained in the mixed culture system while in single culture fermentations of Lactobacillus casei or Lactococcus lactis, the maximum concentration of lactic acid was 53 and 46 g l⁻¹, respectively. In the case of single Lactobacillus casei or Lactococcus lactis, the total percentage of glucose and fructose utilized were 82.2; 94.4% and 93.8; 60.3%, respectively, whereas in the case of mixed culture, the total percentage of glucose and fructose were 96 and 100%, respectively. These results showed that the mixed culture system gave better results than single cultures regarding lactic acid concentration, and sugar consumption.     

E. coli Nissle microencapsulation in alginate-chitosan nanoparticles and its effect on Campylobacter jejuni in vitro

Microencapsulation enhances the oral delivery of probiotic bacteria. In this study, the probiotic Escherichia coli Nissle 1917 (EcN) was microencapsulated using alginate and chitosan nanoparticles. The result showed 90% encapsulation yield of EcN, and the encapsulated EcN displayed significantly (P < 0.05) increased survival in low pH (1.5), high bile salt concentration (4%), and high temperature (70 °C). The most effective cryopreservatives of EcN during freezing and thawing was skim milk and sucrose. Exposure to microencapsulated EcN significantly (P < 0.05) reduced the Campylobacter jejuni growth by 2 log CFU. The rate of EcN release from microcapsule was 9.2 × 10⁵ cell min⁻¹, and the appropriate model to describe its release kinetics was zero order. Importantly, the entrapment of EcN inside the microcapsule did not eliminate the exterior diffusion of EcN produced antioxidant compounds. In addition, the EcN microcapsule efficiently adhered to intestinal HT-29 cells and the pre-treatment of HT-29 cells with EcN-microcapsule for 4 h significantly (P < 0.05) reduced the invasion (1.9 log) of C. jejuni; whereas, completely abolished the intracellular survival. Furthermore, HT-29 cells pre-treated with encapsulated EcN in PCR array showed decreased expression (> 1.5-fold) of genes encoding chemokines, toll-like receptors, interleukins, and tumor necrosis factors. In conclusion, the alginate-chitosan microcapsule can provide effectual platform to deliver probiotic EcN and thereby can reduce the Campylobacter infection in chickens and humans.

     

Efficacy of Probiotic Milk Formula on Blood Lipid and Intestinal Function in Mild Hypercholesterolemic Volunteers: A Placebo-control,Randomized Clinical Trial

Several studies have reported that probiotics could modulate host lipid metabolism via altering the intestinal microbiota. Hence, the current study was aimed to assess the efficacy of a mixture of probiotic-contained milk formula (PMF) with three different bacterial strains [Lactobacillus acidophilus (La5), Lactobacillus casei (TMC), Bifidobacterium lactis (Bb12)] on lipid profile and intestinal function in healthy mild hypercholesterolemic volunteers. Totally, 40 healthy mild hypercholesterolemic subjects (180–220 mg/dL) were randomly assigned into two groups as placebo or experimental group. All the subjects were requested to drink either PMF (experimental) or skimmed milk drink formula-placebo (30 g mixed with 200 mL of water) for 10 weeks and continued by 2 weeks of the follow-up period. Supplementation of PMF for 10 weeks significantly improved (p < 0.05) the fecal weight, fecal movement (decreased fecal gastrointestinal passing time) by improving intestinal microbiota (increasing beneficial bacterial species like Lactobacillus, Bifidobacterium spp.), and lag time of low-density lipoprotein (LDL) oxidation. Also, intake of PMF substantially reduced (p < 0.05) the levels of total cholesterol (TC; 8.1%) and low-density lipoprotein cholesterol (LDL-c; 10.4%) and thus showcasing its cardioprotective efficacy. PMF considerably improves gastrointestinal function by modulating fecal movement, intestinal microbiota, and decrease cholesterol and might be helpful in the management of hypercholesterolemia.

     

Probiotic Lactobacillus casei Expressing Human Lactoferrin Elevates Antibacterial Activity in the Gastrointestinal Tract

In this study, Lactobacillus casei was used to deliver and express human lactoferrin (hLF) to protect the host against bacterial infection. Full-length hLF cDNA was cloned into a Lactobacillus-specific plasmid to produce the L. casei transformants (rhLF/L. casei). Antimicrobial activity of recombinant hLF was examined in inhibition of bacteria growth in vitro. A mouse model was established to test in vivo antibacterial activity and protective effect of orally-administered probiotic L. casei transformant in the gastrointestinal tract. Trials were conducted in which animals were challenged with E. coli ATCC25922. E. coli colony numbers in duodenal fluid from the group fed with rhLF/L. casei were significantly lower than those of the group fed with wild-type L. casei or placebo (P < 0.01). Histopathological analyses of the small intestine, showed both decreased intestinal injury and increased villi length were observed in the mice fed with rhLF/L. casei as compared with the control groups (P < 0.01). Our results demonstrate that L. casei expressing hLF exhibited antibacterial activity both in in vitro and in vivo. It also provides a potentially large-scale production of hLF as applications for treatment of infections caused by clinically relevant pathogens.     

Efficient production and secretion of bovine β-lactoglobulin by <Emphasis Type="Italic">Lactobacillus casei</Emphasis>

Background  

Lactic acid bacteria (LAB) are attractive tools to deliver therapeutic molecules at the mucosal level. The model LAB Lactococcus lactis has been intensively used to produce and deliver such heterologous proteins. However, compared to recombinant lactococci, lactobacilli offer some advantages such as better survival in the digestive tract and immunomodulatory properties. Here, we compared different strategies to optimize the production of bovine β-lactoglobulin (BLG), a major cow's milk allergen, in the probiotic strain Lactobacillus casei BL23.     

Bacterial diversity and community structure during fermentation of Chinese sauerkraut with Lactobacillus casei 11MZ‐5‐1 by Illumina Miseq sequencing

The bacterial diversity and community structure involved in Chinese sauerkraut is one of the most important factors shaping the final characteristics of traditional foods. In this research, Lactobacillus casei 11MZ‐5‐1 was applied in Chinese sauerkraut fermentation as a starter culture. Illumina Miseq sequencing analysis was used to reveal the bacterial diversity and community structure during Chinese sauerkraut fermentation. A total of 177 283 high‐quality reads of 16S rRNA V4 regions were obtained. The inoculation of L. casei 11MZ‐5‐1 decreased considerably the bacterial richness and bacterial diversity. This inoculum led to the replacement of Lactococcus by Lactobacillus. The levels of Pseudomonas and Enterobacter bacteria decreased. These findings reveal the evolution of important bacterial groups that are involved in fermentation and will facilitate improvements in the Chinese sauerkraut fermentation process.

Significance and Impact of the Study

This research thoroughly revealed the effects of Lactobacillus casei 11MZ‐5‐1 starter cultures on bacterial communities during Chinese sauerkraut fermentation. Illumina Miseq sequencing was effective technique to monitor the bacterial diversity and community structure. The inoculation of L. casei 11MZ‐5‐1 led to the decline of bacterial richness and diversity together with a consistent predominance of Lactobacillus during spontaneous fermentation. The result collectively suggested L. casei 11MZ‐5‐1 is a promising starter in Chinese sauerkraut manufacturing.     

Therapeutic Prospective of a Spore-Forming Probiotic—Bacillus clausii UBBC07 Against Acetaminophen-Induced Uremia in Rats

To screen Bacillus clausii UBBC07 as a putative probiotic strain and to examine the protective effect of probiotic—B. clausii UBBC07 spore on uremia on rats induced by acetaminophen. In vitro tests performed to screen potential probiotic strains were gastric and bile acid resistance and ability to reduce pathogen adhesion to surfaces. An in vivo study was performed on rats (n = 18) which were randomly divided into three groups: group I, control—receives normal food and water, groups II and III receive acetaminophen i.p. at the dose of 550 mg/kg/day for 10 days, groups III was treated with B. clausii UBBC07 at a dose of 1 × 10⁹ CFU/day for 15 days. Urea, creatinine, malondialdehyde (MDA), and GSH levels and antioxidant enzymes like super oxide dismutase (SOD) and catalase activity were considered to analyze renal failure. Plasma urea and creatinine levels (p < 0.05) significantly increase and SOD, catalase, and GSH activity level significantly decrease in group II as compared with the control group. After treatment with probiotic, there was a significant increase in SOD and catalase (p < 0.05) and a significant decrease in serum urea, creatinine, and MDA (p < 0.05) in group III in response to group II. The results also revealed that probiotic was able to tolerate pH 3.0–9.0 and 0.3% bile salt. The present study suggests that B. clausii UBBC07 could be used as a novel alternative natural therapy for uremia, a major syndrome of CKD.

     

Lactobacillus reuteri KT260178 Supplementation Reduced Morbidity of Piglets Through Its Targeted Colonization,Improvement of Cecal Microbiota Profile,and Immune Functions

Supplementing suckling piglets with Lactobacillus reuteri isolated from a homologous source improves L. reuteri colonization number in the gastrointestinal tract, which can have health benefits. This study investigated dietary L. reuteri supplementation on the growth and health—including immune status—of piglets, as well as its colonization. A total of 60 sows with similar parity and body weight were allocated into one of three groups after secretion (n = 20 each, with 10 neonatal piglets of each): untreated control, L. reuteri supplementation, and antibiotic treatment. The experimental duration was 28 days, from birth of piglets to their group transferred. For the first 7 days after birth, all neonatal piglets were fed by sows. Piglets in the L. reuteri supplementation group were administered with 1.0 ml L. reuteri fermentation broth containing 5.0 × 10⁷ CFU. From 7 to 28 days, piglets were given basal feed (control), basal feed supplemented with L. reuteri (1.0 × 10⁷ CFU/g), or aureomycin (150 mg/kg). L. reuteri colonization in the distal jejunum and ileum was increased in piglets in the L. reuteri-supplemented as compared to the control group after 28 days, as determined by fluorescence in situ hybridization and real-time PCR analysis. Total Lactobacillus and Bifidobacterium counts in the cecum were higher whereas total aerobic bacteria (Escherichia coli and Staphylococcus) counts were lower in the L. reuteri as compared to the control group. L. reuteri supplementation also improved body antioxidant status and immune function relative to control animals. Strain-specific L. reuteri administered to piglets colonizes the intestinal mucosa and improves cecal microbiota profile and whole-body antioxidant and immune status, leading to better growth and lower morbidity and mortality rates.

     

Effects of Lactobacillus rhamnosus ATCC 7469 on Different Parameters Related to Health Status of Rainbow Trout (Oncorhynchus mykiss) and the Protection Against Yersinia ruckeri

In the current study, we investigated the effect of a probiotic bacterium (Lactobacillus rhamnosus ATCC 7469) microencapsulated with alginate and hi-maize starch and coated with chitosan on improving growth factors, body composition, blood chemistry, and the immune response of rainbow trout (initial weight: 18.41 ± 0.32 g). Four experimental diets were formulated to feed fish for 60 days. They were control diet without any additive (C), diet added with beads without probiotic (E), a probiotic sprayed to the diet (L.r), and encapsulated probiotic supplemented diet (E-L.r). The results indicated that feeding with E-Lr significantly improved weight gain (84.98 g) and feed conversion ratio (0.95) compared to the other groups (P < 0.05). Also, fish fed E-Lr diet had a significantly higher value of whole-body protein (17.51%), total protein in the blood (4.98 g/dL), lysozyme (30.66 U/mL), alternative complement pathway hemolytic activity (134 U/mL), superoxide dismutase (203 U/mg protein), and catalase (528.33 U/mg protein) (P < 0.05) as compared to those fed the control diet. Similarly, a higher relative expression of immune-related genes such as interleukin-1 (Il-1) and tumor necrosis factor-alpha (TNF-1α) were reported in those fed E-L.r and L.r diets respectively. Interestingly, the fish fed dietary E-L.r had a significantly lower value of lipid in the whole body (4.82%) and cholesterol in the blood (160.67%) in comparison with those fed the control diet (P < 0.05). At the end of the experiment, all groups were challenged by Yersinia ruckeri where the survival rate of rainbow trout fed dietary E-L.r (70.36%) was statistically higher than that of the others (P < 0.05). Overall, the results suggested that encapsulated probiotic Lact. rhamnosus ATCC 7469 acted better than unencapsulated probiotic and has a potential to improve growth performance, flesh quality, and the immune response of rainbow trout.

     

A practical random mutagenesis system for probiotic Lactobacillus casei using Tn5 transposition complexes

Aims: Despite the fact that the entire genome sequence of probiotic Lactobacillus casei has recently been available, their mechanisms of beneficial effects are poorly clarified, probably because of the lack of an efficient mutagenesis system. The aim of this study was to establish a practical random mutagenesis system of L. casei using the Tn5 transposome complexes. Methods and Results: We optimized the conditions for transformation using a plasmid pUCYIT356‐1‐Not2 and then transposition reaction using Tn5 transposome system for L. casei ATCC 27139. Tn5 insertion library of this strain being consisted of 9408 mutants was constructed by repeating the mutagenesis procedure. To examine the utility of this mutagenesis system, we screened a panel of insertion mutants for nutrient requirements. Six auxotrophic mutants were isolated and their Tn5 insertion sites were determined by inverse PCR, which demonstrated that insertions occur randomly throughout the whole bacterial genome. Conclusions: Tn5 transposome system functioned efficiently to generate transposon insertion mutants of L. casei and enabled to construct useful L. casei Tn5 insertion library at optimized conditions for transformation and transposition. Significance and Impact of the Study: The availability of this system facilitates the study of the mechanisms of beneficial effects of L. casei for human health.     

The Effect of Lactobacillus casei Consumption in Improvement of Obsessive–Compulsive Disorder: an Animal Study

Obsessive–compulsive disorder (OCD) is an important neuropsychiatric disorder worldwide. Common treatments of OCD include serotonergic antidepressants, which can cause potentially serious side effects. We assessed the effects of Lactobacillus casei (L. casei) Shirota consumption in an animal model of OCD. OCD-like symptoms were induced in rats by the chronic injection of the D2/D3 dopamine agonist quinpirole hydrochloride. Rats were classified into five groups of 6 rats. Four groups were injected chronically with quinpirole (0.5 mg/kg, twice weekly for 5 weeks). They were fed with L. casei Shirota (10⁹ CF/g, daily for 4 weeks) (group 1), fluoxetine (10 mg/kg, daily for 4 weeks) (group 2), combination of L. casei Shirota and fluoxetine (group 3), and normal saline (positive control group). The last group did not receive dopamine agonist and was only injected with saline (negative control group). Expression levels of brain-derived neurotrophic factor (Bdnf), solute carrier family 6 member 4 (Slc6a4), and 5-hydroxytryptamine receptor type 2A (Htr2a) were assessed in orbitofrontal cortex tissues of all rats. Behavioral tests showed improvement of OCD signs in rats treated with L. casei Shirota, fluoxetine, and a combination of drugs. Quantitative PCR analysis showed a remarkable decrease in the expression of Bdnf and an increase in the expression of Htr2a in quinpirole-treated rats. After treatment with L. casei Shirota and fluoxetine, the expression level of Bdnf was increased remarkably, whereas Htr2a expression was decreased. The current study showed the effectiveness of L. casei Shirota in the treatment of OCD in a rat model. The beneficial effects of this probiotic are possibly exerted through the modulation of serotonin-related genes expression.

     

Evaluation of the Impacts of Long-Term Enriched Artemia with Bacillus subtilis on Growth Performance,Reproduction, Intestinal Microflora,and Resistance to Aeromonas hydrophila of Ornamental Fish Poecilia latipinna

The present study investigated the effect of enriched Artemia with Bacillus subtilis on growth performance, reproductive factors, proximate composition, intestinal microflora, and resistance to Aeromonas hydrophila of ornamental fish, Poecilia latipinna. Using a completely randomized design, the experiment included three groups. The first group was fed with commercial food without any probiotic. The second group was fed with unenriched Artemia, and the last group consumed long-time enriched Artemia with Bacillus subtilis. The bacteria B. subtilis with a density of 1 × 10⁵ CFU mL⁻¹ was added daily to Artemia culture medium. The total microflora and Bacillus subtilis counts were significantly increased in enriched Artemia compared to the unenriched group (P < 0.05). In fish fed groups, growth factors did not show any significant difference (P > 0.05). The maximum relative fecundity (28.65 ± 2.52 egg number g⁻¹), fry production (62.93 ± 4.6 individual per female), and fry survival (70.97 ± 1.56%) obtained in the third group were found to be significantly more than those in the first and the second groups. Moreover, intestinal bacterial count for Bacillus revealed that the higher concentration of bacteria was significantly related to the third group (6.24 ± 0.11 log CFU g⁻¹) (P < 0.05). Maximum protein and fat contents were observed in fish fed with Bacillus-enriched Artemia; however, no significant difference was found between control and unenriched Artemia groups (P > 0.05). The highest amount of ash was observed in fish fed with commercial food without any probiotic (P < 0.05). At the end of the feeding period, each of the three groups along with positive group (oxytetracycline 100 mg kg⁻¹ of commercial food) was exposed to A. hydrophila (BCCM5/LMG3770) bacteria intraperitoneally. Based on the results, the lowest cumulative mortality was significantly found in group three (68.75 ± 3.6%) and positive group (62.5 ± 7.0%) compared to control and unenriched Artemia groups (P < 0.05). Hence, B. subtilis with a concentration of 1 × 10⁵ CFU mL⁻¹ during the period of Artemia culturing can improve the reproductive parameters, intestinal microflora, and resistance to pathogenic bacteria of Poecilia latipinna.

     

An In Vitro Study on Bacterial Growth Interactions and Intestinal Epithelial Cell Adhesion Characteristics of Probiotic Combinations

The aims of this study were to examine long-term growth interactions of five probiotic strains (Lactobacillus casei 01, Lactobacillus plantarum HA8, Lactobacillus rhamnosus GG, Lactobacillus reuteri ATCC 55730 and Bifidobacterium lactis Bb12) either alone or in combination with Propionibacterium jensenii 702 in a co-culture system and to determine their adhesion ability to human colon adenocarcinoma cell line Caco-2. Growth patterns of probiotic Lactobacillus strains were not considerably affected by the presence of P. jensenii 702, whereas lactobacilli exerted a strong antagonistic action against P. jensenii 702. In the co-culture of Bif. lactis Bb12 and P. jensenii 702, a significant synergistic influence on growth of both bacteria was observed (P < 0.05). The results of adhesion assay showed that when probiotic strains were tested in combination, there was evidence of an associated effect on percentage adherence. However, in most cases these differences were not statistically significant (P < 0.05). Adhesion percentage of Lb. casei 01 and Lb. rhamnosus GG both decreased significantly in the presence of P. jensenii 702 compared to their adhesion levels when alone (P < 0.05). These results show that the survival and percentage adhesion of some probiotic strains may be influenced by the presence of other strains and this should be considered when formulating in the probiotic products.