Bifidobacterium longum GL001 alleviates rat intestinal ischemia-reperfusion injury by modulating gut microbiota composition and intestinal tissue metabolism.

Intestinal ischemia-reperfusion (IIR) injury leads to inflammation and oxidative stress, resulting in intestinal barrier damage. Probiotics, due to their anti-inflammatory and antioxidant properties, are considered for potential intervention to protect the intestinal barrier during IIR injury. Bifidobacterium longum, a recognized probiotic, has targeted effects on IIR injury, but its mechanisms of action are not yet understood. To investigate the mechanism of Bifidobacterium longum intervention in IIR injury, we conducted a study using a rat IIR injury model. The results showed that Bifidobacterium longum could alleviate inflammation and oxidative stress induced by IIR injury by suppressing the NF-κB inflammatory pathway and activating the Keap1/Nrf2 signaling pathway. Bifidobacterium longum GL001 also increased the abundance of the gut microbiota such as Oscillospira, Ouminococcus, Corynebacterium, Lactobacillus, and Akkermansia, while decreasing the abundance of Allobaculum, [Prevotella], Bacteroidaceae, Bacteroides, Shigella, and Helicobacter. In addition, Bifidobacterium longum GL001 reversed the changes in amino acids and bile acids induced by IIR injury and reduced the levels of DL-cysteine, an oxidative stress marker, in intestinal tissue. Spearman correlation analysis showed that L-cystine was positively correlated with Lactobacillus and negatively correlated with Shigella, while DL-proline was positively correlated with Akkermansia. Moreover, bile acids, cholic acid and lithocholic acid, were negatively correlated with Lactobacillus and positively correlated with Shigella. Therefore, Bifidobacterium longum GL001 may alleviate IIR injury by regulating the gut microbiota to modulate intestinal lipid peroxidation and bile acid metabolism.

Lactobacillus plantarum and Bifidobacterium longum Alleviate Liver Injury and Fibrosis in Mice by Regulating NF-κB and AMPK Signaling.

In a preliminary study, live biotherapeutic products (LBPs) Lactobacillus plantarum LC27 and Bifidobacterium longum LC67 inhibited the secretion of alanine transaminase (ALT) and aspartate transaminase (AST) in LPS-stimulated HepG2 cells, while Escherichia coli K1 (Ec) increased ALT and ALT secretion. Therefore, we examined the effects of LC27 and LC67 on LPS-induced liver injury and fibrosis in mice and the correlation between their biomarkers in cell and animal experiments. Orally administered LC27 or LC67 significantly decreased blood ALT, AST, γ-glutamyl transferase (γGTP), TNF-α, triglyceride (TG), total cholesterol (TCh), total bile acid, and LPS levels, liver TNF-α, toll-like receptor-4 gene (Tlr4), α-smooth muscle actin (αSMA), and collagen-1 expression and αSMA+GFAP+ and NF-κB+F4/80+ cell populations, and colonic Tlr4, TNF-α, and IL-6 expression and NF-κB-positive cell population in LPS-treated mice. Furthermore, they increased AMPKa phosphorylation in the liver and colon. However, Ec increased the expression of TNF-α and IL-6 in blood, liver, and colon. The suppression of LPS-stimulated ALT and AST secretion in HepG2 cells by LBPs was positively correlated with their ameliorating effects on LPS-induced blood γGTP, ALT, and AST levels and liver αSMA and collagen-1 expression in mice. Based on these findings, LC27 and LC67 may improve liver injury and fibrosis by regulating NF-κB and AMPK signaling pathway and a protocol that can assay the inhibitory activity of LBPs on LPS-induced ALT and AST secretion in HepG2 may be useful for guessing their antihepatitic effects in the in vivo experiments.

Exploring the Potential of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 as Promising Psychobiotics Using SHIME.

Psychobiotics are probiotics that have the characteristics of modulating central nervous system (CNS) functions or reconciled actions by the gut-brain axis (GBA) through neural, humoral and metabolic pathways to improve gastrointestinal activity as well as anxiolytic and even antidepressant abilities. The aim of this work was to evaluate the effect of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on the gut microbiota of mildly anxious adults using SHIME®. The protocol included a one-week control period and two weeks of treatment with L. helveticus R0052 and B. longum R0175. Ammonia (NH4+), short chain fatty acids (SCFAs), gamma-aminobutyric acid (GABA), cytokines and microbiota composition were determined. Probiotic strains decreased significantly throughout the gastric phase. The highest survival rates were exhibited by L. helveticus R0052 (81.58%; 77.22%) after the gastric and intestinal phase when compared to B. longum (68.80%; 64.64%). At the genus level, a taxonomic assignment performed in the ascending colon in the SHIME® model showed that probiotics (7 and 14 days) significantly (p < 0.005) increased the abundance of Lactobacillus and Olsenella and significantly decreased Lachnospira and Escheria-Shigella. The probiotic treatment (7 and 14 days) decreased (p < 0.001) NH4+ production when compared to the control period. For SCFAs, we observed after probiotic treatment (14 days) an increase (p < 0.001) in acetic acid production and total SCFAs when compared to the control period. Probiotic treatment increased (p < 0.001) the secretion of anti-inflammatory (IL-6 and IL-10) and decreased (p < 0.001) pro-inflammatory cytokines (TNF-alpha) when compared to the control period. The gut-brain axis plays an important role in the gut microbiota, producing SCFAs and GABA, stimulating the production of anti-anxiety homeostasis. The signature of the microbiota in anxiety disorders provides a promising direction for the prevention of mental illness and opens a new perspective for using the psychobiotic as a main actor of therapeutic targets.

Exercise training combined with Bifidobacterium longum OLP-01 treatment regulates insulin resistance and physical performance in db/db mice.

Type 2 diabetes mellitus (T2DM) is a prevalent chronic disease characterized by hyperglycemia and insulin resistance. Regular exercise is one of the effective lifestyle interventions for maintaining healthy weight and blood glucose levels in the normal range and lowering risk factors. Probiotics, live microorganisms that are beneficial to health, are involved in the regulation of host metabolism. We thus hypothesize that the combination of exercise training and Bifidobacterium longum OLP-01 (OLP-01) could improve insulin sensitivity, blood glucose control and body composition in db/db mice. Twenty-four C57BL/6 J db/db male mice (20-weeks old) were divided into four groups (n = 6 per group): vehicle, OLP-01 supplementation (OLP-01), exercise training (EX) and exercise training with OLP-01 supplementation (EX + OLP-01). Animals in the EX and EX + OLP-01 groups underwent strength exercise training for 6 weeks, 5 days per week. After the exercise training, we tested forelimb grip strength, exhaustive running, oral glucose tolerance test (OGTT) and serum biomarkers. Results: Combined intervention of EX and OLP-01 prevented elevation of body weight and body fat. Grip strength and exhaustive swimming time were significantly higher in the EX + OLP-01 group than in the other groups. We found that EX OLP-01 reduced glycolipid parameters (fasting blood glucose and hemoglobin A1c), improved insulin sensitivity (oral glucose tolerance test and HOMA-IR), relieved liver injury parameters (aspartate aminotransferase and alanine aminotransferase) and repaired pancreas damage. Based on our findings, we speculate that the positive effects of combining EX with OLP-01 on capacity for physical activity, blood glucose control and body composition suggest an integrative approach to treating type 2 diabetes. Altogether, the combination of EX with OLP-01 treatment might be a good candidate for preventing and treating diabetes.

Identification of the key characteristics of Bifidobacterium longum strains for the alleviation of ulcerative colitis.

Bifidobacterium longum (B. longum) species are widely used to prevent and treat ulcerative colitis (UC). In this study, phylogenetic and pan-genomic characterization of 122 B. longum strains was performed on the basis of 936 core genes; among these, four strains from different branches of the phylogenetic tree were selected for an evaluation of anti-inflammatory and immune modulatory activities in a DSS-induced colitis mouse model. Among the tested B. longum strains (B. longum FBJ20M1, B. longum FGDLZ8M1, B. longum FGSZY16M3, and B. longum FJSWXJ2M1), B. longum FGDLZ8M1 was found to most effectively alleviate colitis by reducing the expression of pro-inflammatory cytokines, restoring the colon length, and maintaining the mucosal integrity. The anti-inflammatory mechanisms of B. longum FGDLZ8M1 were related to the inhibition of NF-κB signaling. Genomic analysis indicated that these protective effects of B. longum FGDLZ8M1 may be related to specific genes associated with carbohydrate transport and metabolism and defense mechanisms (e.g., tolerance to bile salts and acids). Correlation analysis indicated that gastrointestinal transit tolerance was the most strongly associated factor. Our findings may contribute to the rapid screening of lactic acid bacterial strains with UC-alleviating effects.

Effective removal of lead (II) using chitosan and microbial adsorbents: Response surface methodology (RSM).

The ability of chitosan (1% w/v), Bifidobacterium longum (108 CFU mL-1) and Saccharomyces cerevisiae (108 CFU mL-1) separately or in combination (chitosan/B. longum, chitosan/S. cerevisiae, B. longum/S. cerevisiae) was assessed for lead (II) removal from aqueous solutions. The results showed chitosan/B. longum adsorbent had higher adsorption percentage in comparison with other adsorbents (p < 0.05). It was selected as the most efficient adsorbent and the effect of process variables including initial metal concentration (0.01-5 mg L-1), contact time (5-180 min), temperature (4-37 °C) and pH (3-6) on the its removal efficiency was evaluated with a Box-Behnken design. Twenty-seven test runs were performed and the optimal conditions for metal adsorption was observed at metal concentration of 2.5 mg L-1, contact time of 180 min, temperature of 37 °C and pH 4.5. The maximum lead (II) adsorption yield under optimal conditions was 97.6%. The foreign ions didn't diminish lead (II) adsorption by chitosan/B. longum and it had high selectivity toward the lead (II). Adsorption behavior was analyzed using the Freundlich and the Langmuir isotherms. The correlation coefficients (R2) demonstrated the Langmuir model had a better description on metal adsorption process. Overall, isotherms revealed chemisorption and physisorption were probably involved in metal adsorption on adsorbent.

Interactions of Oxysterols with Atherosclerosis Biomarkers in Subjects with Moderate Hypercholesterolemia and Effects of a Nutraceutical Combination (Bifidobacterium longum BB536, Red Yeast Rice Extract) (Randomized, Double-Blind, Placebo-Controlled Study).

BACKGROUND: Oxysterol relationship with cardiovascular (CV) risk factors is poorly explored, especially in moderately hypercholesterolaemic subjects. Moreover, the impact of nutraceuticals controlling hypercholesterolaemia on plasma levels of 24-, 25- and 27-hydroxycholesterol (24-OHC, 25-OHC, 27-OHC) is unknown. METHODS: Subjects (n = 33; 18-70 years) with moderate hypercholesterolaemia (low-density lipoprotein cholesterol (LDL-C:): 130-200 mg/dL), in primary CV prevention as well as low CV risk were studied cross-sectionally. Moreover, they were evaluated after treatment with a nutraceutical combination (Bifidobacterium longum BB536, red yeast rice extract (10 mg/dose monacolin K)), following a double-blind, randomized, placebo-controlled design. We evaluated 24-OHC, 25-OHC and 27-OHC levels by gas chromatography/mass spectrometry analysis. RESULTS: 24-OHC and 25-OHC were significantly correlated, 24-OHC was correlated with apoB. 27-OHC and 27-OHC/total cholesterol (TC) were higher in men (median 209 ng/mL and 77 ng/mg, respectively) vs. women (median 168 ng/mL and 56 ng/mg, respectively); 27-OHC/TC was significantly correlated with abdominal circumference, visceral fat and, negatively, with high-density lipoprotein cholesterol (HDL-C). Triglycerides were significantly correlated with 24-OHC, 25-OHC and 27-OHC and with 24-OHC/TC and 25-OHC/TC. After intervention, 27-OHC levels were significantly reduced by 10.4% in the nutraceutical group Levels of 24-OHC, 24-OHC/TC, 25-OHC, 25-OHC/TC and 27-OHC/TC were unchanged. CONCLUSIONS: In this study, conducted in moderate hypercholesterolemic subjects, we observed novel relationships between 24-OHC, 25-OHC and 27-OHC and CV risk biomarkers. In addition, no adverse changes of OHC levels upon nutraceutical treatment were found.

Strain-Specific Effects of Bifidobacterium longum on Hypercholesterolemic Rats and Potential Mechanisms.

Hypercholesterolemia is an independent risk factor of cardiovascular disease, which is among the major causes of death worldwide. The aim of this study was to explore whether Bifidobacterium longum strains exerted intra-species differences in cholesterol-lowering effects in hypercholesterolemic rats and to investigate the potential mechanisms. SD rats underwent gavage with each B. longum strain (CCFM 1077, I3, J3 and B3) daily for 28 days. B. longum CCFM 1077 exerted the most potent cholesterol-lowering effect, followed by B. longum I3 and B3, whereas B. longum B3 had no effect in alleviating hypercholesterolemia. Divergent alleviation of different B. longum strains on hypercholesterolemia can be attributed to the differences in bile salt deconjugation ability and cholesterol assimilation ability in vitro. By 16S rRNA metagenomics analysis, the relative abundance of beneficial genus increased in the B. longum CCFM 1077 treatment group. The expression of key genes involved in cholesterol metabolism were also altered after the B. longum CCFM 1077 treatment. In conclusion, B. longum exhibits strain-specific effects in the alleviation of hypercholesterolemia, mainly due to differences in bacterial characteristics, bile salt deconjugation ability, cholesterol assimilation ability, expressions of key genes involved in cholesterol metabolism and alterations of gut microbiota.

Potentiated antitumor effects of APS001F/5-FC combined with anti-PD-1 antibody in a CT26 syngeneic mouse model.

APS001F is a strain of Bifidobacterium longum genetically engineered to express cytosine deaminase that converts 5-fluorocytosine (5-FC) to 5-fluorouracil. In the present study, antitumor effects of APS001F plus 5-FC (APS001F/5-FC) in combination with anti-PD-1 monoclonal antibody were investigated using a CT26 syngeneic mouse model. Both of dosing of APS001F/5-FC before and after anti-PD-1 mAb in the combination dosing exhibited antitumor effects as well as prolonged survival over the nontreated control. The survival rate in the combination therapy significantly increased over the monotherapy with APS001F/5-FC and that with anti-PD-1 mAb. Regulatory T cells among CD4+ T cells in tumor decreased in the combination therapy, while the ratio of CD8+ T cells was maintained in all groups. Taken these results together, APS001F/5-FC not only demonstrates a direct antitumor activity, but also immunomodulatory effects once localized in the hypoxic region of the tumor, which allows anti-PD-1 mAb to exert potentiated antitumor effects.

Preventive oral supplementation with Bifidobacterium longum 51A alleviates oxazolone-induced allergic contact dermatitis-like skin inflammation in mice.

Allergic contact dermatitis (ACD) is a common allergic skin disease that affects individuals subjected to different antigen exposure conditions and significantly impacts the quality of life of those affected. Numerous studies have demonstrated that probiotics suppress inflammation through immunomodulatory effects. In this study, we aimed to evaluate the effect of the probiotic Bifidobacterium longum 51A as a preventive treatment for ACD using an oxazolone-induced murine model. We demonstrated that B. longum 51A exerted a prophylactic effect on oxazolone-induced ACD-like skin inflammation via reductions in ear and dermal thickness and leucocyte infiltration. The administration of inactivated B. longum 51A did not affect oxazolone-induced ACD-like skin inflammation, suggesting that the bacteria must be alive to be effective. Given that B. longum 51A is an acetate producer, we treated mice with acetate intraperitoneally, which also prevented ear and dermal thickening. Moreover, the tissue levels of the inflammatory cytokines and chemokines interleukin (IL)-10, IL-33, tumour necrosis factor-α, chemokine (C-C motif) ligand 2/monocyte chemoattractant protein-1 and chemokine (C-C motif) ligand 5/RANTES were significantly reduced after probiotic treatment, but only IL-33 and IL-10 were reduced when the mice were treated with acetate. These results show that B. longum 51A exerted a potential prophylactic effect on skin inflammation and that acetate represents one potential mechanism. However, other factors are likely involved since these two treatments do not yield the same results.

Oral Probiotic Bifidobacterium Longum Supplementation Improves Metabolic Parameters and Alters the Expression of the Renin-Angiotensin System in Obese Mice Liver.

BACKGROUND: Obesity and non-alcoholic fatty liver disease (NAFLD) have been increasing at an alarming rate worldwide. Bifidobacterium longum (BL), a common member of the human gut microbiota, has important health benefits through several mechanisms. OBJECTIVES: We evaluated the BL supplementation effects on body metabolism and renin-angiotensin components hepatic expression in mice fed a high-fat diet. METHODS: Thirty-two male mice were divided into four groups: standard diet + placebo (ST), standard diet + Bifidobacterium longum (ST + BL), high-fat diet + placebo (HFD) and high-fat diet + Bifidobacterium longum (HFD + BL). Following the obesity induction period, the ST + BL and HFD + BL groups were supplemented with Bifidobacterium longum for 4 weeks. Then, body, biochemical, histological and molecular parameters were evaluated. RESULTS: HFD + BL mice had a significant decrease in adipose tissue mass and blood glucose levels, as well as a significant reduction in blood glucose during an intraperitoneal glucose tolerance test. The treatment also resulted in reduced levels of total cholesterol and hepatic fat accumulation. Moreover, we observed an increase in angiotensin converting enzyme 2 (ACE2) and Mas receptor (MASR) expression levels in BL-treated obese mice. CONCLUSIONS: These data demonstrate that BL may have the potential to prevent obesity and NAFLD by modulating the mRNA expression of renin-angiotensin system components.

Bifidobacterium longum counters the effects of obesity: Partial successful translation from rodent to human.

BACKGROUND: The human gut microbiota has emerged as a key factor in the development of obesity. Certain probiotic strains have shown anti-obesity effects. The objective of this study was to investigate whether Bifidobacterium longum APC1472 has anti-obesity effects in high-fat diet (HFD)-induced obese mice and whether B. longum APC1472 supplementation reduces body-mass index (BMI) in healthy overweight/obese individuals as the primary outcome. B. longum APC1472 effects on waist-to-hip ratio (W/H ratio) and on obesity-associated plasma biomarkers were analysed as secondary outcomes. METHODS: B. longum APC1472 was administered to HFD-fed C57BL/6 mice in drinking water for 16 weeks. In the human intervention trial, participants received B. longum APC1472 or placebo supplementation for 12 weeks, during which primary and secondary outcomes were measured at the beginning and end of the intervention. FINDINGS: B. longum APC1472 supplementation was associated with decreased bodyweight, fat depots accumulation and increased glucose tolerance in HFD-fed mice. While, in healthy overweight/obese adults, the supplementation of B. longum APC1472 strain did not change primary outcomes of BMI (0.03, 95% CI [-0.4, 0.3]) or W/H ratio (0.003, 95% CI [-0.01, 0.01]), a positive effect on the secondary outcome of fasting blood glucose levels was found (-0.299, 95% CI [-0.44, -0.09]). INTERPRETATION: This study shows a positive translational effect of B. longum APC1472 on fasting blood glucose from a preclinical mouse model of obesity to a human intervention study in otherwise healthy overweight and obese individuals. This highlights the promising potential of B. longum APC1472 to be developed as a valuable supplement in reducing specific markers of obesity. FUNDING: This research was funded in part by Science Foundation Ireland in the form of a Research Centre grant (SFI/12/RC/2273) to APC Microbiome Ireland and by a research grant from Cremo S.A.

Antidiabetic effects of selenium-enriched Bifidobacterium longum DD98 in type 2 diabetes model of mice.

Both selenium and probiotics have shown antidiabetic effects in a type 2 diabetes model. The objective of this study is to investigate the alleviating effects of selenium-enriched Bifidobacterium longum DD98 (Se-B. longum DD98) on diabetes in mice and explore the possible underlying mechanism. A type 2 diabetes model was established using a high-fat diet and streptozotocin (STZ) injection in mice. To investigate the beneficial effects of Se-B. longum DD98, diabetic mice were then treated with B. longum DD98, Se-B. longum DD98, or sodium selenite (Na2SeO3) for three weeks. The results suggested that all three treatments could reduce the levels of fasting blood glucose (FBG), glycated hemoglobin (HbA1c), insulin and leptin, improve glucose tolerance, regulate lipid metabolism, and protect against the impairment of the liver and pancreas, while Se-B. longum DD98 showed a greater effect on relieving the above mentioned symptoms of type 2 diabetes in mice. Furthermore, this effect was associated with butyrate production and inflammatory response. Se-B. longum DD98 better increased the level of butyrate in feces and decreased the levels of proinflammatory cytokines in the pancreas compared with B. longum DD98 and Na2SeO3, leading to ameliorative insulin resistance. Se-B. longum DD98 also improved the glucagon like peptide-1 (GLP-1) level in serum and intestinal cells, which protected the pancreatic ß-islet cells from damage induced by type 2 diabetes. These results demonstrated that Na2SeO3, B. longum DD98, or Se-B. longum DD98 could alleviate the progression of type 2 diabetes in mice. Se-B. longum DD98 showed greater antidiabetic effects than the other two treatments, and could be considered as a promising candidate for treating type 2 diabetes.

Adaptational changes in physiological and transcriptional responses of Bifidobacterium longum involved in acid stress resistance after successive batch cultures.

Bifidobacterium inhabiting the human and animal intestinal tract is known for its health-promoting effect. Tolerance to acid stress is crucial for bifidobacteria to survive and then exert their beneficial effects in the gut. A long-term adaptation in successive batch cultures was used as evolutionary engineering strategy to improve acid stress tolerance in an industrial probiotic strain, B. longum JDM301. Its derivative, JDM301AR showed higher resistance to several stress conditions, including acid stress than the parental strain, JDM301. To better understand bifidobacterial acid stress response, the changes of fatty acid (FA) in cell membrane of these two strains were determined. A shift in the production of FA in cell membrane, characterized by increased C14:0 was found, when JDM301AR was exposed to low-pH environment. It was implied that the increased production of C14:0 is associated with the acquisition of acid-tolerant phenotype for JDM301AR. High-throughput RNA-sequencing was performed to analyze the changes of gene expression profile after acid-exposure. The transcriptional profiles of JDM301AR and JDM301 under normal condition and acid stress were compared to reveal the different acid response between them. A total of 5 genes involved in FA metabolism were upregulated and no downregulated genes were found in response to acid stress in JDM301AR. The up-regulated BLJ_0565 and BLJ_1105 may play important roles in the modification of membrane FA composition of JDM301AR after acid exposure. Overall, these results suggested that successive batch cultures induced the acid stress tolerance of B. longum involved in transcriptional and physiological responses, including modification of cell wall and cell membrane, metabolism of amino acid and neutralization of internal pH by strengthening NH3 production and transport.

Oral Administration of Microencapsulated B. Longum BAA-999 and Lycopene Modulates IGF-1/IGF-1R/IGFBP3 Protein Expressions in a Colorectal Murine Model.

The Insulin-like growth factor-I/Insulin-like growth factor-I receptor (IGF-1/IGF-1R) system is a major determinant in colorectal cancer (CRC) pathogenesis. Probiotics (Bifidobacterium longum, BF) and lycopene (LYC) have been individually researched for their beneficial effects in the prevention of CRC. However, the effect of a combined treatment of microencapsulated BF and LYC on IGF-1/IGF-1R/IGFBPs (Insulin-like growth factor-binding proteins) expression in an azoxymethane (AOM)-dextran sulfate sodium (DSS)-induced CRC model have not been demonstrated. BF was microencapsulated by the spray drying technique, with high viability, and daily gavaged with LYC for 16 weeks to CD-1 mice in an AOM-DSS model. The results indicated that BF- and BF + LYC-treated groups had significantly lower inflammation grade, tumor incidence (13-38%) and adenocarcinoma (13-14%) incidence compared to the AOM + DSS group (80%), whereas LYC treatment only protected against inflammation grade and incidence. Caecal, colonic and fecal pH and ß-glucuronidase (ß-GA) values were significantly normalized by BF and LYC. Similarly, BF and BF + LYC treatments significantly reduced both the positive rate and expression grade of IGF-1 and IGF-1R proteins and normalized Insulin-like growth factor-binding protein-3 (IGFBP3) expression. Based on intestinal parameters related to the specific colon carcinogenesis in an AOM-DSS-induced model, LYC and microencapsulated BF supplementation resulted in a significant chemopreventive potential through the modulation of IGF-1/IGF-1R system.

Suppression of gut dysbiosis by Bifidobacterium longum alleviates cognitive decline in 5XFAD transgenic and aged mice.

To understand the role of commensal gut bacteria on the progression of cognitive decline in Alzheimer's disease via the microbiota-gut-brain axis, we isolated anti-inflammatory Bifidobacterium longum (NK46) from human gut microbiota, which potently inhibited gut microbiota endotoxin production and suppressed NF-κB activation in lipopolysaccharide (LPS)-stimulated BV-2 cells, and examined whether NK46 could simultaneously alleviate gut dysbiosis and cognitive decline in male 5xFAD-transgenic (5XFAD-Tg, 6 months-old) and aged (18 months-old) mice. Oral administration of NK46 (1 × 109 CFU/mouse/day for 1 and 2 months in aged and Tg mice, respectively) shifted gut microbiota composition, particularly Proteobacteria, reduced fecal and blood LPS levels, suppressed NF-κB activation and TNF-α expression, and increased tight junction protein expression in the colon of 5XFAD-Tg and aged mice. NK46 treatment also alleviated cognitive decline in 5XFAD-Tg and aged mice. Furthermore, NK46 treatment suppressed amyloid-ß, ß/γ-secretases, and caspase-3 expression and amyloid-ß accumulation in the hippocampus of 5XFAD-Tg mice. NK46 treatment also reduced Iba1+, LPS+/CD11b+, and caspase-3+/NeuN+ cell populations and suppressed NF-κB activation in the hippocampus of 5XFAD-Tg and aged mice, while BDNF expression was increased. These findings suggest that the suppression of gut dysbiosis and LPS production by NK46 can mitigate cognitive decline through the regulation of microbiota LPS-mediated NF-κB activation.

Lactobacillus plantarum NK3 and Bifidobacterium longum NK49 Alleviate Bacterial Vaginosis and Osteoporosis in Mice by Suppressing NF-κB-Linked TNF-α Expression.

Excessive expression of TNF-α worsens bacterial vaginosis (BV) and osteoporosis. Therefore, to understand whether probiotics could alleviate vaginosis and osteoporosis, we isolated anti-inflammatory Lactobacillus plantarum NK3 and Bifidobacterium longum NK49 from kimchi and human fecal lactic acid bacteria collection and examined their effects on Gardnerella vaginalis (GV)-induced vaginosis and ovariectomy-induced osteoporosis in female mice. Oral gavage of NK3 and/or NK49 significantly alleviated GV-induced vaginosis; these inhibited NF-κB activation and TNF-α expression in the vagina and uterus, and decreased the GV population in the vagina. Furthermore, treatment with NK3 and/or NK49 alleviated ovariectomy-induced osteoporosis and obesity; these increased blood calcium, phosphorus, and osteocalcin levels and suppressed body weight. GV-induced vaginosis and ovariectomy increased colonic myeloperoxidase activity, TNF-α expression, and fecal Proteobacteria population. NK3 and/or NK49 treatments reduced TNF-α expression and NF-κB activation in the colon. NK3 and NK49 treatment also restored GV- or ovariectomy-disrupted gut microbiota composition. In conclusion, NK3 and NK49 may simultaneously alleviate BV and osteoporosis by suppressing NF-κB-linked TNF-α expression through the regulation of gut microbiota population.

In vitro modulation of human gut microbiota composition and metabolites by Bifidobacterium longum BB-46 and a citric pectin.

The gut microbiota composition and its metabolites have high impact on human health. Exploitation of prebiotics and probiotics for modulation of gut microbiota can lead to promising outcomes. This study aimed to evaluate the effects of the probiotic strain Bifidobacterium longum BB-46 alone and in combination with a citric pectin from lemon on the gut microbiota from healthy adults using the Simulator of Human Intestinal Microbial Ecosystem (SHIME®). Changes in microbiota composition and in metabolic activity were assessed by the 16S rRNA gene sequencing and by analyses of short-chain fatty acids (SCFAs) and ammonium ions (NH4+). An increase in the relative abundances of Firmicutes (especially the members of Lachnospiraceae and Lactobacillaceae families) and Bacteroidetes was observed during treatment with B. longum BB-46 alone in all compartments of the colon. Treatment with B. longum BB-46 and pectin stimulated an increase in the proportions of genera Faecalibacterium, Eubacterium and Lactobacillus, as well as in the Ruminococcaceae family in the transverse and descending colons. Concurrently, the butyrate levels increased in these two compartments. Additionally, the combination of B. longum BB-46 and pectin reduced the abundance of proteolytic bacteria Bacteroides, Clostridium, Peptoniphilus, and Streptococcus, along with decreased NH4+ production. No significant changes could be observed on NH4+ production by treatment with B. longum BB-46, nor did it increase the amount of SCFAs. In this study, we observed that although each treatment was able to modulate the microbiota, the combination of B. longum BB-46 and pectin was more efficient in decreasing the intestinal NH4+ levels and in increasing butyric acid-producing bacteria. These findings indicate that B. longum BB-46, especially when combined with the specific citric pectin, might have beneficial impact on human health.

Bifidobacterium longum R0175 attenuates post-myocardial infarction depressive-like behaviour in rats.

Caspase-3 activation in the limbic system and depressive-like symptoms are observed after an acute myocardial infarction (MI) and studies suggest that inflammation may play a significant role. Combined treatment with the probiotic strains Bifidobacterium longum and Lactobacillus helveticus in rats has been shown to attenuate caspase-3 activation and depressive-like behaviour together with a reduction in pro-inflammatory cytokines. The present study was designed to determine the respective contribution of these two strains on caspase-3 activity in the limbic system and on depressive-like behaviour. Sprague-Dawley rats were assigned to one of four groups: Vehicle, L. helveticus R0052, B. longum R0175 and L. salivarius HA-118, administered orally for 14 days (109CFU daily) before inducing MI by occlusion of the left anterior descending artery for 40 min followed by 14 days of reperfusion. Animals were then tested for socialisation, passive avoidance and forced swim test to assess depressive-like behaviour. At day 18 the animals were sacrificed; infarct size was estimated, plasma C-reactive protein concentration and brain caspase-3 activity were measured. Results indicated that infarct size did not vary across the different treatments. Rats treated with B. longum spent more time socializing, learned more rapidly the passive avoidance test and spent less time immobile in the forced swim test compared to the vehicle groups. Caspase-3 activity and plasma C-reactive protein concentrations were reduced in the lateral and medial amygdala as well as in the dentate gyrus of B. longum-supplemented animals. The only significant effect in the two groups receiving Lactobacilli compared to vehicle was that rats receiving L. salivarius learned more rapidly in the step-down passive avoidance test. In conclusion, most of the beneficial effects that we previously reported with the combination of two probiotic strains in our experimentation regarding post-myocardial infarction depression are related to Bifidobacterium longum.

Bifidobacterium longum IM55 and Lactobacillus plantarum IM76 alleviate allergic rhinitis in mice by restoring Th2/Treg imbalance and gut microbiota disturbance.

This study aimed to examine whether probiotics, which suppressed the differentiation of splenic T cells into type 2 helper T (Th2) cells and induced into regulatory T cells in vitro, alleviate allergic rhinitis (AR) and gut microbiota disturbance. We isolated Bifidobacterium longum IM55 and Lactobacillus plantarum IM76 from human faecal microbiota and kimchi, respectively, and examined their effects on ovalbumin (OVA)-induced AR and gut microbiota disturbance in mice. Treatment with IM55, IM76, or their probiotic mixture (PM) significantly reduced OVA-induced allergic nasal symptoms and blood immunoglobulin E (IgE) levels in mice. These also reduced OVA-induced interleukin (IL)-4 and IL-5 levels in nasal tissues and bronchoalveolar lavage fluid (BALF) but increased OVA-suppressed IL-10 levels. Treatment with IM55, IM76, or PM reduced OVA-induced increase in the populations of mast cells, eosinophils, and Th2 cells and increased OVA-suppressed population of regulatory T cells in the BALF. Treatment with IM55, IM76, or PM also inhibited OVA-induced expression of IL-5 in lung and colon tissues and restored OVA-disturbed composition of gut microbiota Proteobacteria, Bacteroidetes, and Actinobacteria. These results suggest that IM55 and IM67 can alleviate AR by restoring Th2/Treg imbalance and gut microbiota disturbance.