Bifidobacterium lactis attenuates onset of inflammation in a murine model of colitis

Bifidobacterium improves oestrogen-deficiency-induced osteoporosis in mice by modulating intestinal immunity

Osteoporosis has become one of the major diseases that threaten the health of middle-aged and elderly people, and with the growth of an ageing population, more and more people are affected by osteoporosis these days. In recent years, intestinal flora has been found to affect the host immune system, and an overactive immune system is closely related to bone resorption. Probiotics can effectively improve bone density and strength, reduce bone loss, and improve osteoporosis, but their mechanism of action and relationship with intestinal microbiota are still unclear. In this study, two strains of Bifidobacterium (Bifidobacterium bifidum FL228.1 and Bifidobacterium animalis subsp. Lactis F1-7) that can alleviate intestinal inflammation were screened based on previous experiments. Through the construction of an ovariectomized mouse model, the improvement of osteoporosis by Bifidobacterium was detected, and the influence of Bifidobacterium on intestinal immunity was explored. The results show that Bifidobacterium treatment significantly improved bone mineral density (BMD), bone volume/total volume ratio (BV/TV), and trabecular number (Tb·N), and effectively suppressed bone loss. Furthermore, Bifidobacterium treatment could inhibit the expression of inflammatory cytokines in the gut, alleviate gut inflammation, and thus suppress excessive osteoclast generation. Its mechanism of action includes factors that protect the mucosal barrier, including occludin, ZO-1, claudin-2, and MUC2, and the reduction of pro-inflammatory M1 macrophages. B. bifidum FL228.1 increased the abundance of beneficial bacteria in the colon, including Lactobacillus and Colidextribacter. B. animalis F1-7 increased the abundance of Bifidobacterium and decreased the abundance of Desulfovibrio and Ruminococcus in the colon. These research findings expand our understanding of the gut-bone axis and provide new guidance for the development of probiotic-based therapies for osteoporosis in the future.

Pharmacological benefits of Acacia against metabolic diseases: intestinal-level bioactivities and favorable modulation of gut microbiota

CONTEXT

Obesity-associated chronic metabolic disease is a leading contributor to mortality globally. Plants belonging to the genera Acacia are routinely used for the treatment of diverse metabolic diseases under different ethnomedicinal practices around the globe.

OBJECTIVE

The current review centres around the pharmacological evidence of intestinal-level mechanisms for metabolic health benefits by Acacia spp.

RESULTS

Acacia spp. increase the proportions of gut commensals (Bifidobacterium and Lactobacillus) and reduces the population of opportunistic pathobionts (Escherichia coli and Clostridium). Acacia gum that is rich in fibre, can also be a source of prebiotics to improve gut health. The intestinal-level anti-inflammatory activities of Acacia are likely to contribute to improvements in gut barrier function that would prevent gut-to-systemic endotoxin translocation and limit "low-grade" inflammation associated with metabolic diseases.

CONCLUSION

This comprehensive review for the first time has emphasised the intestinal-level benefits of Acacia spp. which could be instrumental in limiting the burden of metabolic disease.

Screening for Lactic Acid Bacterial Strains as Probiotics Exhibiting Anti-inflammatory and Antioxidative Characteristic Via Immune Modulation in HaCaT Cell

In this study, the basic probiotic characteristics and functional properties of lactic acid bacteria (LAB) were investigated using two in vitro models of inflammation induced by lipopolysaccharide (LPS) and H2O2. Fifteen strains were prescreened out of 60 LAB candidates based on their radical scavenging activity to determine the antioxidant capacity of the strains. The top 15 candidates were further investigated to evaluate their survival rate under low pH and bile salt conditions that mimic the intestinal environment. Three strains, Levilactobacillus brevis D70 (Levilact), Lactiplantibacillus pentosus S16 (Lactipla), and Limosilactobacillus fermentum MF10 (Limosilact), were capable of scavenging free radicals and survived under artificial intestinal conditions. Therefore, Levilact. brevis D70, Lactipla. pentosus S16, and Limosilact. fermentum MF10 were selected for further antioxidant, anti-inflammation, and mitochondrial activity examinations via cell models of inflammation and oxidative stress. Among the three strains, Limosilact. fermentum MF10 showed the highest anti-inflammatory activities by significantly downregulating the relative mRNA expression levels of inflammatory biomarkers such as interleukin 8 (IL-8) and interferon-gamma (IFN-γ) induced by LPS (P < 0.05). Moreover, Limosilact. fermentum MF10 was also capable of upregulating the gene expression levels of antioxidative mediator glutathione peroxidase 4 (GPX4) induced by reactive oxygen species (ROS) in both human HT-29 epithelial cells and human HaCaT keratinocytes. Limosilact. fermentum MF10 was also capable of regulating mitochondrial membrane potential (MMP), which plays a key role in the mitochondrial activity of HaCaT cells. As a result, Limosilact. fermentum MF10 showed the highest potential for probiotic properties and impacts the immune-related gut-skin axis by altering proinflammatory cytokines, antioxidative biomarkers, and MMP.

Ameliorating inflammation in an in vitro model by screening the anti-inflammatory and immunomodulatory roles of putative probiotics in inflammatory bowel disease

IBD is considered a relapsing disease with relapsing phases. Probiotics are beneficial microorganisms that modulate inflammatory signaling pathways. Our aim was to identify the precise molecular effects of probiotics on inflammatory signaling pathways during the presence of inflammation. Evaluation of the expression of JAK/STAT and inflammatory genes after treatment of the HT -29 cell line with the sonicated pathogens and probiotics, simultaneously was performed by quantitative real-time polymerase chain reaction (qPCR) assay. The production of IL-6 and IL-1β after administration of probiotics was conducted by means of cytokine assay. The probiotic cocktail resulted in the downregulation of TIRAP, IRAK4, NEMO, and RIP genes in the NF-кB pathway compared with Sonicat-treated cells. The expression of JAK/STAT genes was various after probiotic treatment. The application of probiotics has been observed to result in a notable decrease in the production of IL-6 and IL-1β. The investigated probiotic cocktail, especially Bifidobacterium spp. showed anti-inflammatory effects on HT -29 cells via modulation of JAK/STAT and NF-кB signaling pathways. The use of probiotics with the least side effects could be considered a suitable treatment for patients with inflammatory bowel disease, even at the beginning of inflammation.

Gut Microbes Are Associated with the Vascular Beneficial Effects of Dietary Strawberry on Metabolic Syndrome-Induced Vascular Inflammation

SCOPE

Metabolic syndrome (MetS) alters the gut microbial ecology and increases the risk of cardiovascular disease. This study investigates whether strawberry consumption reduces vascular complications in an animal model of MetS and identifies whether this effect is associated with changes in the composition of gut microbes.

METHODS AND RESULTS

Seven-week-old male mice consume diets with 10% (C) or 60% kcal from fat (high-fat diet fed mice; HF) for 12 weeks and subgroups are fed a 2.35% freeze-dried strawberry supplemented diet (C+SB or HF+SB). This nutritional dose is equivalent to ≈160 g of strawberry. After 12 weeks treatment, vascular inflammation is enhanced in HF versus C mice as shown by an increased monocyte binding to vasculature, elevated serum chemokines, and increased mRNA expression of inflammatory molecules. However, strawberry supplementation suppresses vascular inflammation in HF+SB versus HF mice. Metabolic variables, blood pressure, and indices of vascular function were similar among the groups. Further, the abundance of opportunistic microbe is decreased in HF+SB. Importantly, circulating chemokines are positively associated with opportunistic microbes and negatively associated with the commensal microbes (Bifidobacterium and Facalibaculum).

CONCLUSION

Dietary strawberry decreases the abundance of opportunistic microbe and this is associated with a decrease in vascular inflammation resulting from MetS.

Effect of Crohn's disease mesenteric mesenchymal stem cells and their extracellular vesicles on T-cell immunosuppressive capacity

Crohn's disease (CD) is a chronic inflammatory disease of the gastrointestinal intestinal tract and has characteristic hypertrophic adipose changes observed in the mesentery. To better understand the role of the mesentery in the pathophysiology of Crohn's disease (CD), we evaluated the immunomodulatory potential of mesenchymal stem cells (MSCs) and their secreted extracellular vesicles (EVs) derived from Crohn's patients. MSCs and EVs were isolated from the mesentery and subcutaneous tissues of CD patients and healthy individuals subcutaneous tissues, and were analysed for differentiation, cytokine expression, self‐renewal and proliferation. The varying capacity of these tissue‐derived MSCs and EVs to attenuate T‐cell activation was measured in in vitro and an in vivo murine model. RNA sequencing of inflamed Crohn's disease mesentery tissue revealed an enrichment of T‐cell activation compared to non‐inflamed subcutaneous tissue. MSCs and MSC‐derived EVs isolated from Crohn's mesentery lose their ability to attenuate DSS‐induced colitis compared to subcutaneous tissue‐derived cell or EV therapy. We found that treatment with subcutaneous isolated MSCs and their EV product compared to Crohn's mesentery MSCs or EVs, the inhibition of T‐cell proliferation and IFN‐γ, IL‐17a production increased, suggesting a non‐inflamed microenvironment allows for T‐cell inhibition by MSCs/EVs. Our results demonstrate that Crohn's patient‐derived diseased mesentery tissue MSCs lose their immunosuppressive capacity in the treatment of colitis by distinct regulation of pathogenic T‐cell responses and/or T‐cell infiltration into the colon.

Beneficial effects of Lactococcus lactis subsp. cremoris LL95 treatment in an LPS-induced depression-like model in mice

Clinical evidence suggests that neuroinflammation, activation of the immune system, and the composition of the intestinal microbiota are involved in the pathology of depression. This study evaluated the effectiveness of a probiotic intervention using Lactococcus lactis subsp. cremoris LL95 in ameliorating mood disorders in a lipopolysaccharide (LPS)-induced depression-like mouse model. C57BL/6 mice were randomly divided into four groups and treated with 5 mg/kg LPS via intraperitoneal injection to induce depression-like symptoms, followed by oral administration of LL95 for one week (1 × 109 CFU/mouse). The animals were then subjected to a series of behavioral assessments, including open field, sucrose preference, and forced swimming tests. In addition, we evaluated the levels of reactive oxygen species, tumor necrosis factor-α, and interleukin-1β in the hippocampal tissues of these animals, and also determined their fecal lactic acid bacteria (LAB) content. LL95 intervention improved LPS-induced depression-like behaviors in mice, including decreased sucrose preference and increased immobility time in the forced swim test. LL95 treatment reversed the LPS-induced increase in hippocampal levels of reactive oxygen species and tumor necrosis factor-α, and of interleukin-1β to a lesser extent. Furthermore, LL95 intervention increased the fecal LAB content in these animals, suggesting changes in the gut microbiota. These findings suggest that LL95 exerts antidepressant-like effects in LPS-induced depression, which may be attributed to modulation of the oxidative status and pro-inflammatory cytokine expression in the hippocampus and alteration in the LAB content of the gut microbiota.

Dietary Blueberry Ameliorates Vascular Complications in Diabetic Mice Possibly through NOX4 and Modulates Composition and Functional Diversity of Gut Microbes

SCOPE

In diabetes, endothelial inflammation and dysfunction play a pivotal role in the development of vascular disease. This study investigates the effect of dietary blueberries on vascular complications and gut microbiome in diabetic mice.

METHODS AND RESULTS

Seven-week-old diabetic db/db mice consume a standard diet (db/db) or a diet supplemented with 3.8% freeze-dried blueberry (db/db+BB) for 10 weeks. Control db/+ mice are fed a standard diet (db/+). Vascular inflammation is assessed by measuring monocyte binding to vasculature and inflammatory markers. Isometric tension procedures are used to assess mesenteric artery function. db/db mice exhibit enhanced vascular inflammation and reduced endothelial-dependent vasorelaxation as compared to db/+ mice, but these are improved in db/db+BB mice. Blueberry supplementation reduces the expression of NOX4 and IκKβ in the aortic vessel and vascular endothelial cells (ECs) isolated from db/db+BB compared to db/db mice. The blueberry metabolites serum reduces glucose and palmitate induced endothelial inflammation in mouse aortic ECs. Further, blueberry supplementation increases commensal microbes and modulates the functional potential of gut microbes in diabetic mice.

CONCLUSION

Dietary blueberry suppresses vascular inflammation, attenuates arterial endothelial dysfunction, and supports the growth of commensal microbes in diabetic mice. The endothelial-specific vascular benefits of blueberries are mediated through NOX4 signaling.

Bifidobacterium lactis BL-99 protects mice with osteoporosis caused by colitis via gut inflammation and gut microbiota regulation

Patients diagnosed with inflammatory bowel disease or related conditions also frequently suffer from osteoporosis as a consequence of changes in the intestinal microenvironment and consequent dysbiosis. We hypothesized that anti-inflammatory probiotic treatment would be sufficient to alleviate intestinal inflammation and thereby prevent the development of osteoporosis. To that end, the ability of Bifidobacterium lactis BL-99 administration to protect against bone loss in an experimental model of dextran sodium sulfate-induced ulcerative colitis (UC) was analyzed, and the underlying molecular mechanisms were interrogated in detail. The results of these analyses revealed that BL-99 administration suppressed colitis-associated weight loss (P < 0.05), disease activity index scores, and the production of proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-17) (P < 0.05). Colon tissue pathological sections similarly revealed BL-99-mediated reductions in tissue injury severity. Micro-computed tomography (Micro-CT) analyses further exhibited significant improvements in percent bone volume (BV/TV) as well as trabecular number and thickness in BL-99-treated animals (P < 0.05). Such probiotic supplementation also resulted in pronounced changes in the composition of the gut microbiota. Moreover, BL-99 intervention markedly increased the expression of intestinal barrier-related proteins (Claudin-1, MUC2, ZO-1, and Occludin). Together, these results suggest that BL-99 can be utilized as a beneficial probiotic preparation to prevent the incidence of osteoporosis in UC patients owing to its ability to shape the intestinal microflora and to suppress inflammatory cytokine production.

Maternal Lactobacillus reuteri supplementation shifts the intestinal microbiome in mice and provides protection from experimental colitis in female offspring

The purpose of our experiment was to explore how stochastic (inter-individual variation) gut microbiome composition may link to inflammatory bowel disease (IBD) susceptibility and guide the development of a perinatal preventative probiotic. Dextran sodium sulfate (DSS) was introduced to C57BL/BJ mice to induce acute colitis as a model of IBD. Potentially protective bacteria were identified using a discovery-validation cohort approach toward stochastic DSS susceptibility. Lactobacilli (two different cocktails of L. reuteri and L. johnsonii strains) or control media were supplemented by mouth to dams prior to delivery and during lactation (i.e., perinatal probiotic). The pups were evaluated for DSS susceptibility at young adulthood. Fecal Lactobacillus was increased in the DSS-resistant mice in both the discovery and validation cohorts. Maternal supplementation of female offspring with an L. reuteri cocktail (strains 6798-1, 6798-jm, and 6798-cm) induced progressive microbiome separation and protection against colitis by young adulthood. Maternal supplementation of L. reuteri could confer protection against DSS colitis in young adult female mice. This work is the first to exploit stochastic mammalian microbiome variation to guide microbial therapeutic identification. Our findings underscore neonatal microbiome plasticity and set the stage for the potential development of perinatally deliverable protective probiotics against human IBD.

Evidence of MHC class I and II influencing viral and helminth infection via the microbiome in a non-human primate

Until recently, the study of major histocompability complex (MHC) mediated immunity has focused on the direct link between MHC diversity and susceptibility to parasite infection. However, MHC genes can also influence host health indirectly through the sculpting of the bacterial community that in turn shape immune responses. We investigated the links between MHC class I and II gene diversity gut microbiome diversity and micro- (adenovirus, AdV) and macro- (helminth) parasite infection probabilities in a wild population of non-human primates, mouse lemurs of Madagascar. This setup encompasses a plethora of underlying interactions between parasites, microbes and adaptive immunity in natural populations. Both MHC classes explained shifts in microbiome composition and the effect was driven by a few select microbial taxa. Among them were three taxa (Odoribacter, Campylobacter and Prevotellaceae-UCG-001) which were in turn linked to AdV and helminth infection status, correlative evidence of the indirect effect of the MHC via the microbiome. Our study provides support for the coupled role of MHC diversity and microbial flora as contributing factors of parasite infection.

The selective pressure of the major histocompatibility complex (MHC) on microbial communities, and the potential role of this interaction in driving parasite resistance has been largely neglected. Using a natural population of the primate Microcebus griseorufus, we provide correlative evidence of two outstanding findings: that MHCI and MHCII diversity shapes the composition of the gut microbiota; and that select taxa associated with MHC diversity predicted adenovirus and helminth infection status. Our study highlights the importance of incorporating the microbiome when investigating parasite-mediated MHC selection.

Anti-inflammatory and Anti-osteoporotic Potential of Lactobacillus plantarum A41 and L. fermentum SRK414 as Probiotics

This study involves an investigation on the probiotic properties of lactic acid bacteria and their potential applications in an in vitro model of lipopolysaccharide (LPS)-stimulated inflammation and dexamethasone-induced osteoporosis. Nine strains were pre-screened from 485 lactic acid bacteria based on their survival at a low pH and in a solution containing bile salts. All candidates were capable of surviving in an environment with low pH and with bile salts and could successfully colonize the intestine. Furthermore, their functional properties, such as anti-oxidation and anti-inflammation, were evaluated. Of the nine probiotic candidates, Lactobacillus plantarum A41 and L. fermentum SRK414 exhibited the highest anti-oxidative capacity. Moreover, only L. plantarum A41 and L. fermentum SRK414 could increase gut barrier function by upregulating the mRNA expression of tight junction proteins and inhibit the expression of inflammatory mediators induced by LPS-stimulated inflammation. Interestingly, these two strains were also capable of regulating several bone metabolism-related markers playing a role in bone homeostasis and osteoblast differentiation. In brief, L. plantarum A41 and L. fermentum SRK414 exhibited high probiotic potential and potentially impact immune-related bone health by modulating pro-inflammatory cytokines and bone metabolism-related markers.

Nicotinamide Ameliorates Dextran Sulfate Sodium-Induced Chronic Colitis in Mice through Its Anti-Inflammatory Properties and Modulates the Gut Microbiota

Vitamin B (nicotinamide (NAM)), one of the most important nutritional components for humans, exerts anti-inflammatory activity. This study was aimed at investigating the effect of NAM on the gut microbiota and short-chain fatty acids (SCFAs) in mice with chronic colitis. Colitis was induced in C57BL/6 male mice by administration of 1.5% dextran sulfate sodium (DSS), and the mice were intraperitoneally injected with normal saline (NS) or NAM. NAM treatment ameliorated weight loss and changes in colon length, disease activity index (DAI) score, and histologic scores. Moreover, enzyme-linked immunosorbent assay (ELISA) analysis of LPL cells revealed that the level of interleukin- (IL-) 6, IL-12p70, IL-1β, tumor necrosis factor- (TNF-) α, interferon- (IFN-) γ, IL-21, and IL-17A was increased, while IL-10 was reduced, in the chronic colitis group compared to the control group, but the levels of all these factors were restored after NAM treatment. Then, 16S rRNA sequencing of the large intestinal content was performed, and analysis of alpha diversity and beta diversity showed that the richness of the gut microbiota was decreased in the DSS group compared to the control group and restored after NAM treatment. In addition, NAM modulated specific bacteria, including Odoribacter, Flexispira, and Bifidobacterium, in the NAM+chronic colitis group. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis indicated that NAM treatment restored disruptions in the functions of the gut microbiota (replication and repair, cell motility) in mice with DSS-induced colitis. Furthermore, NAM also restored the reduction in valeric acid in mice with DSS-induced chronic colitis. Our results suggest that NAM treatment could alleviate DSS-induced chronic colitis in mice by inhibiting inflammation and regulating the composition and function of gut microbiota.

Study on the additive protective effect of PGLYRP3 and Bifidobacterium adolescentis Reuter 1963 on severity of DSS-induced colitis in Pglyrp3 knockout (Pglyrp3 -/-) and wild-type (WT) mice

BACKGROUND AND AIMS

Pglyrp3 is a bactericidal innate immunity protein known to sustain the habitual gut microbiome and protect against experimental colitis. Intestinal inflammation and metaflammation are commonly associated with a marked reduction of commensal bifidobacteria. Whether Pglyrp3 and bifidobacteria interact synergistically or additively to alleviate metaflammation is unknown. We investigated the extent to which Pglyrp3 and bifidobacteria regulate metaflammation and gut bacterial dysbiosis in DSS-induced mouse models of intestinal inflammation.

MATERIAL & METHODS

8-10 weeks old male mice were used. In both WT and Pglyrp3 -/- experiments, the mice were randomly divided into three groups of 16 mice per group: (1) a control group receiving sterile tap water, (2) an experimental group receiving sterile tap water supplemented with only 5% DSS, and (3) an experimental group receiving sterile tap water supplemented with 5% DSS and 1 × 10⁹ CFU/ml of Bifidobacterium adolescentis (B.a.) for 7 days. Wild-type (WT) littermates of the respective gene (i.e. Pglyrp3) were used as controls throughout the study. Clinical signs of general health and inflammation were monitored daily. Faecal pellet samples were analysed by qRT-PCR for microbial composition. Histology of relevant organs was carried out on day 8. Metabolic parameters and liver inflammation were determined in serum samples.

RESULTS

Intestinal inflammation in mice of group 2 were significantly increased compared to those of control group 1. There was a significant difference in mean scores for inflammation severity between DSS-treated WT and DSS-treated Pglyrp3 -/- mice. Buildup of key serum metabolic markers (cholesterol, triglyceride and glucose) was set off by colonic inflammation. qRT-PCR quantification showed that DSS significantly decreased the Clostridium coccoides and Bifidobacterium cell counts while increasing those of Bacteroides group in both WT and Pglyrp3 -/- mice. These manifestations of DSS-induced dysbiosis were significantly attenuated by feeding B.a. Both the local and systemic ill-being of the mice alleviated when they received B.a.

DISCUSSION

This study shows that Pglyrp3 facilitates recognition of bifidobacterial cell wall-derived peptidoglycan, thus leading additively to a reduction of metaflammation through an increase in the number of bifidobacteria, which were able to mitigate intestinal immunopathology in the context of Pglyrp3 blockade.

Study on the Intervention Effect of Qi Gong Wan Prescription on Patients with Phlegm-Dampness Syndrome of Polycystic Ovary Syndrome Based on Intestinal Flora

Objective

This was a population-based cohort study, to compare the type and structure of intestinal flora in patients with polycystic ovary syndrome (PCOS) with phlegm-dampness syndrome, nonphlegm-dampness syndrome, and normal population. Besides, changes in the intestinal flora and the clinical curative effects of Jiawei Qi Gong Wan on phlegm-dampness syndrome in patients with polycystic ovary syndrome (PCOS) were evaluated. Patients and Methods. A total of 22 patients with PCOS with phlegm-dampness syndrome, 21 PCOS patients with nonphlegm-dampness syndrome, and 20 control volunteers were selected for this study. The general index, sex hormone index, fasting blood glucose (FPG), and serum fasting insulin (FINS) were determined in each of the groups. The intestinal flora of each group was determined by the 16s rDNA high-throughput sequencing technique. Besides, the PCOS with phlegm-dampness syndrome group was treated with Jiawei Qi Gong Wan, and the changes in TCM syndrome, sex hormone index, BMI, WHR, FPG, FINS, HOMA-IR, and intestinal flora were determined before and after treatment.

Results

PCOS patients with phlegm-dampness syndrome showed characteristics of obesity and insulin resistance. There were several differences in both structure and function of the intestinal flora between PCOS patients with phlegm-dampness syndrome, PCOS patients with nonphlegm-dampness syndrome, and the control group. An imbalance in the intestinal flora may be a key factor in the pathogenesis of PCOS with phlegm-dampness syndrome and also has a specific influence on glucose and lipid metabolism, obesity, and the menstrual cycle in PCOS patients with phlegm-dampness syndrome. Besides, the imbalance is associated with a decrease in the number of butyrate-producing bacteria, an increase in the number of lipopolysaccharide-producing bacteria, and an increase in proinflammatory bacteria. The intestinal flora in PCOS patients with phlegm-dampness syndrome was found to be linked to obesity, impaired glucose tolerance, and hyperandrogenemia. Treatment with Jiawei Qi Gong Wan was found to increase the diversity of intestinal flora, increase the number of intestinal probiotics, and improve the structure and functional genes of intestinal flora which improved the state of insulin resistance, regulated endocrine metabolism, and improved the overall symptoms.

Conclusions

Intestinal flora imbalance is a key factor in the pathogenesis of PCOS with phlegm-dampness syndrome. Besides, Jiawei Qi Gong Wan improves insulin resistance which is linked to the status of the intestinal flora in PCOS patients with phlegm-dampness syndrome.

Synbiotic Effect of Bifidobacterium lactis CNCM I-3446 and Bovine Milk-Derived Oligosaccharides on Infant Gut Microbiota

BACKGROUND

This study evaluated the impact of Bifidobacterium animalis ssp. lactis CNCM I-3446, Bovine Milk-derived OligoSaccharides (BMOS) and their combination on infant gut microbiota in vitro. In addition, a novel strategy consisting of preculturing B. lactis with BMOS to further enhance their potential synbiotic effects was assessed.

METHOD

Short-term fecal batch fermentations (48 h) were used to assess the microbial composition and activity modulated by BMOS alone, B. lactis grown on BMOS or dextrose alone, or their combinations on different three-month-old infant microbiota.

RESULTS

BMOS alone significantly induced acetate and lactate production (leading to pH decrease) and stimulated bifidobacterial growth in 10 donors. A further in-depth study on two different donors proved B. lactis ability to colonize the infant microbiota, regardless of the competitiveness of the environment. BMOS further enhanced this engraftment, suggesting a strong synbiotic effect. This was also observed at the microbiota activity level, especially in a donor containing low initial levels of bifidobacteria. In this donor, preculturing B. lactis with BMOS strengthened further the early modulation of microbiota activity observed after 6 h.

CONCLUSION

This study demonstrated the strong synbiotic effect of BMOS and B. lactis on the infant gut microbiota, and suggests a strategy to improve its effectiveness in an otherwise low-Bifidobacterium microbiota.

Intestinal Dysbiosis and the Developing Lung: The Role of Toll-Like Receptor 4 in the Gut-Lung Axis

Background

In extremely premature infants, postnatal growth restriction (PNGR) is common and increases the risk of developing bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH). Mechanisms by which poor nutrition impacts lung development are unknown, but alterations in the gut microbiota appear to play a role. In a rodent model, PNGR plus hyperoxia causes BPD and PH and increases intestinal Enterobacteriaceae, Gram-negative organisms that stimulate Toll-like receptor 4 (TLR4). We hypothesized that intestinal dysbiosis activates intestinal TLR4 triggering systemic inflammation which impacts lung development.

Methods

Rat pups were assigned to litters of 17 (PNGR) or 10 (normal growth) at birth and exposed to room air or 75% oxygen for 14 days. Half of the pups were treated with the TLR4 inhibitor TAK-242 from birth or beginning at day 3. After 14 days, pulmonary arterial pressure was evaluated by echocardiography and hearts were examined for right ventricular hypertrophy (RVH). Lungs and serum samples were analyzed by western blotting and immunohistochemistry.

Results

Postnatal growth restriction + hyperoxia increased pulmonary arterial pressure and RVH with trends toward increased plasma IL1β and decreased IκBα, the inhibitor of NFκB, in lung tissue. Treatment with the TLR4 inhibitor attenuated PH and inflammation.

Conclusion

Postnatal growth restriction induces an increase in intestinal Enterobacteriaceae leading to PH. Activation of the TLR4 pathway is a promising mechanism by which intestinal dysbiosis impacts the developing lung.

The Epigenetic Connection Between the Gut Microbiome in Obesity and Diabetes

Metabolic diseases are becoming an alarming health issue due to elevated incidences of these diseases over the past few decades. Various environmental factors are associated with a number of metabolic diseases and often play a crucial role in this process. Amongst the factors, diet is the most important factor that can regulate these diseases via modulation of the gut microbiome. The gut microbiome participates in multiple metabolic processes in the human body and is mainly responsible for regulation of host metabolism. The alterations in function and composition of the gut microbiota have been known to be involved in the pathogenesis of metabolic diseases via induction of epigenetic changes such as DNA methylation, histone modifications and regulation by noncoding RNAs. These induced epigenetic modifications can also be regulated by metabolites produced by the gut microbiota including short-chain fatty acids, folates, biotin and trimethylamine-N-oxide. In addition, studies have elucidated the potential role of these microbial-produced metabolites in the pathophysiology of obesity and diabetes. Hence, this review focuses on the interactions between the gut microbiome and epigenetic processes in the regulation and development of obesity and diabetes, which may have potential as a novel preventive or therapeutic approach for several metabolic and other human diseases.

Research progress in the relationship between type 2 diabetes mellitus and intestinal flora

Type 2 diabetes mellitus (T2DM) is a common clinical chronic disease, while its pathogenesis is still inconclusive. Intestinal flora, the largest micro-ecological system in the human body, is involved in, meanwhile has a major impact on the body's material and energy metabolism. Recent studies have shown that in addition to obesity, genetics, and islet dysfunction, the disturbance of intestinal flora may partly give rise to diabetes. In this paper, we summarized the current research on the correlation between T2DM and intestinal flora, and concluded the pathological mechanisms of intestinal flora involved in T2DM. Moreover, the ideas and methods of prevention and treatment of T2DM based on intestinal flora were proposed, providing theoretical basis and literature reference for the treatment of T2DM and its complications based on the regulation of intestinal flora.

Probiotics and the prevention of necrotizing enterocolitis

BACKGROUND

Immaturity of the host immune system and alterations in the intestinal microbiome appear to be key factors in the pathogenesis of necrotizing enterocolitis (NEC). The aim of this paper is to weigh the evidence for the use of probiotics to prevent NEC in premature infants.

METHODS

Animal studies, randomized controlled trials, observational cohort studies and meta-analyses involving administration of probiotic products for the prevention of NEC were reviewed. This review of the evidence summarizes the available preclinical and clinical data.

RESULTS

In animal models probiotic microbes alter the intestinal microbiome, decrease inflammation and intestinal permeability and decrease the incidence and severity of experimental NEC. In randomized, placebo-controlled trials and cohort studies of premature infants, probiotic microbes decrease the risk of NEC, death and sepsis.

CONCLUSION

Evidence is strong for the prevention of NEC with the use of combination probiotics in premature infants who receive breast milk. The potential risks and benefits of probiotic administration to premature infants should be carefully reviewed with parents.

TYPE OF STUDY

Therapeutic.

LEVEL OF EVIDENCE

I.

Dietary supplementation with strawberry induces marked changes in the composition and functional potential of the gut microbiome in diabetic mice

Gut microbiota contributes to the biological activities of berry anthocyanins by transforming them into bioactive metabolites, and anthocyanins support the growth of specific bacteria, indicating a two-way relationship between anthocyanins and microbiota. In the present study, we tested the hypothesis that strawberry supplementation alters gut microbial ecology in diabetic db/db mice. Control (db/+) and diabetic (db/db) mice (7 weeks old) consumed standard diet or diet supplemented with 2.35% freeze-dried strawberry (db/db + SB) for 10 weeks. Colon contents were used to isolate bacterial DNA. V4 variable region of 16S rRNA gene was amplified. Data analyses were performed using standardized pipelines (QIIME 1.9 and R packages). Differences in predictive metagenomics function were identified by PICRUSt. Principal coordinate analyses confirmed that the microbial composition was significantly influenced by both host genotype and strawberry consumption. Further, α-diversity indices and β-diversity were different at the phylum and genus levels, and genus and operational taxonomical units levels, respectively (P<.05). At the phylum level, strawberry supplementation decreased the abundance of Verrucomicrobia in db/db + SB vs. db/db mice (P<.05). At the genus level, db/db mice exhibited a decrease in the abundance of Bifidobacterium, and strawberry supplementation increased Bifidobacterium in db/db + SB vs. db/db mice (P<.05). PICRUSt revealed significant differences in 45 predicted metabolic functions among the 3 groups. Our study provides evidence for marked changes in the composition and functional potential of the gut microbiome with strawberry supplementation in diabetic mice. Importantly, strawberry supplementation increased the abundance of beneficial bacteria Bifidobacterium which play a pivotal role in the metabolism of anthocyanins.

Influence of Maternal Inulin-Type Prebiotic Intervention on Glucose Metabolism and Gut Microbiota in the Offspring of C57BL Mice

Scope: Maternal obesity leads to glucose intolerance in the offspring. Changes in the gut microbiota are being increasingly implicated in the pathogenesis of diabetes. We hypothesized that inulin intervention during gestation and lactation improves glucose metabolism disorders in mouse offspring from high-fat diet (HD)-fed dams. Procedures: Female C57BL mice were fed a control diet or HD for 4 weeks before mating. After mating, pregnant mice were randomly divided into three groups through gestation and lactation: control diet (CD) group, HD group, and HD treated with inulin (HD-inulin) group. At weaning, glucose metabolic status was assessed. Gut microbial DNA from offspring cecal contents was isolated and processed for metagenomic shotgun sequencing, and taxonomic and functional profiling were performed. Results: Offspring from dams in the HD-inulin groups demonstrated reduced fasting blood glucose, decreased blood glucose area under the curve during the oral glucose tolerance test, and reduced fasting serum insulin and HOMA-IR compared to offspring from dams in the HD group. Nineteen differentially abundant bacterial species were identified between the HD-inulin and HD groups. The HD-inulin group displayed significantly greater abundances of Bacteroides_acidifaciens, Eubacterium_sp_CAG_786, Clostridium_sp_CAG_343, and Bifidobacterium_breve species and lower abundances of Oscillibacter_sp_1_3, Ruminococcus_gnavus_CAG_126, and Bacteroides_massiliensis species. Differentially abundant bacterial species among the three groups were involved in 38 metabolic pathways, including several glucose and lipid metabolism pathways. Conclusion: Our results show that early inulin intervention in HD-fed mouse dams moderates offspring glucose metabolism and gut dysbiosis.

Using murine colitis models to analyze probiotics-host interactions

Probiotics are defined as 'live microorganisms which when administered in adequate amounts confer a health benefit on the host'. So, to consider a microorganism as a probiotic, a demonstrable beneficial effect on the health host should be shown as well as an adequate defined safety status and the capacity to survive transit through the gastrointestinal tract and to storage conditions. In this review, we present an overview of the murine colitis models currently employed to test the beneficial effect of the probiotic strains as well as an overview of the probiotics already tested. Our aim is to highlight both the importance of the adequate selection of the animal model to test the potential probiotic strains and of the value of the knowledge generated by these in vivo tests.

Probiotic and anti-inflammatory potential of Lactobacillus rhamnosus 4B15 and Lactobacillus gasseri 4M13 isolated from infant feces

A total of 22 Lactobacillus strains, which were isolated from infant feces were evaluated for their probiotic potential along with resistance to low pH and bile salts. Eight isolates (L. reuteri 3M02 and 3M03, L. gasseri 4M13, 4R22, 5R01, 5R02, and 5R13, and L. rhamnosus 4B15) with high tolerance to acid and bile salts, and ability to adhere to the intestine were screened from 22 strains. Further, functional properties of 8 Lactobacillus strains, such as anti-oxidation, inhibition of α-glucosidase activity, cholesterol-lowering, and anti-inflammation were evaluated. The properties were strain-specific. Particularly, two strains of L. rhamnosus, 4B15 (4B15) and L. gasseri 4M13 (4M13) showed considerably higher anti-oxidation, inhibition of α-glucosidase activity, and cholesterol-lowering, and greater inhibition of nitric oxide production than other strains. Moreover, the two selected strains substantially inhibited the release of inflammatory mediators such as TNF-α, IL-6, IL-1β, and IL-10 stimulated the treatment of RAW 264.7 macrophages with LPS. In addition, whole genome sequencing and comparative genomic analysis of 4B15 and 4M13 indicated them as novel genomic strains. These results suggested that 4B15 and 4M13 showed the highest probiotic potential and have an impact on immune health by modulating pro-inflammatory cytokines.

Mesenchymal stromal cells modulate gut inflammation in experimental colitis

Inflammatory bowel diseases (IBDs) affect millions of people worldwide and their frequencies in developed countries have increased since the twentieth century. In this context, there is an intensive search for therapies that modulate inflammation and provide tissue regeneration in IBDs. Recently, the immunomodulatory activity of adipose tissue-derived mesenchymal stromal cells (ADMSCs) has been demonstrated to play an important role on several immune cells in different conditions of inflammatory and autoimmune diseases. In this study, we explored the immunomodulatory potential of ADMSC in a classical model of DSS-induced colitis. First, we found that treatment of mice with ADMSC ameliorated the severity of DSS-induced colitis, reducing colitis pathological score and preventing colon shortening. Moreover, a prominent reduction of pro-inflammatory cytokines levels (i.e., IFN-γ, TNF-α, IL-6 and MCP-1) was observed in the colon of animals treated with ADMSC. We also observed a significant reduction in the frequencies of macrophages (F4/80⁺CD11b⁺) and dendritic cells (CD11c⁺CD103⁺) in the intestinal lamina propria of ADMSC-treated mice. Finally, we detected the up-regulation of immunoregulatory-associated molecules in intestine of mice treated with ADMSCs (i.e., elevated arginase-1 and IL-10). Thus, this present study demonstrated that ADMSC modulates the overall gut inflammation (cell activation and recruitment) in experimental colitis, providing support to the further development of new strategies in the treatment of intestinal diseases.

Intestinal virome changes precede autoimmunity in type I diabetes-susceptible children

Viruses have long been considered potential triggers of autoimmune diseases. Here we defined the intestinal virome from birth to the development of autoimmunity in children at risk for type 1 diabetes (T1D). A total of 220 virus-enriched preparations from serially collected fecal samples from 11 children (cases) who developed serum autoantibodies associated with T1D (of whom five developed clinical T1D) were compared with samples from controls. Intestinal viromes of case subjects were less diverse than those of controls. Among eukaryotic viruses, we identified significant enrichment of Circoviridae-related sequences in samples from controls in comparison with cases. Enterovirus, kobuvirus, parechovirus, parvovirus, and rotavirus sequences were frequently detected but were not associated with autoimmunity. For bacteriophages, we found higher Shannon diversity and richness in controls compared with cases and observed that changes in the intestinal virome over time differed between cases and controls. Using Random Forests analysis, we identified disease-associated viral bacteriophage contigs after subtraction of age-associated contigs. These disease-associated contigs were statistically linked to specific components of the bacterial microbiome. Thus, changes in the intestinal virome preceded autoimmunity in this cohort. Specific components of the virome were both directly and inversely associated with the development of human autoimmune disease.

The commensal microbiota exacerbate infectious colitis in stressor-exposed mice

Exposure to a prolonged restraint stressor disrupts the colonic microbiota community composition, and is associated with an elevated inflammatory response to colonic pathogen challenge. Since the stability of the microbiota has been implicated in the development and modulation of mucosal immune responses, we hypothesized that the disruptive effect of the stressor upon the microbiota composition directly contributed to the stressor-induced exacerbation of pathogen-induced colitis. In order to establish a causative role for stressor-induced changes in the microbiota, conventional mice were exposed to prolonged restraint to change the microbiota. Germfree mice were then colonized by microbiota from either stressor-exposed or non-stressed control mice. One day after colonization, mice were infected with the colonic pathogen, Citrobacter rodentium. At six days post-infection, mice that received microbiota from stressor-exposed animals had significant increases in colonic pathology and pro-inflammatory cytokine (e.g. IL-1β) and chemokine (e.g. CCL2) levels after C. rodentium infection in comparison with mice that received microbiota from non-stressed mice. 16S rRNA gene sequencing revealed that microbial communities from stressed mice did not have any detectable Bifidobacterium present, a stark contrast with the microbial communities from non-stressed mice, suggesting that stressor-induced alterations in commensal, immunomodulatory Bifidobacterium levels may predispose to an increased inflammatory response to pathogen challenge. This study demonstrates that the commensal microbiota directly contribute to excessive inflammatory responses to C. rodentium during stressor exposure, and may help to explain why gastrointestinal disorders are worsened during stressful experiences.

Insulin resistance is associated with specific gut microbiota in appendix samples from morbidly obese patients

Alterations in intestinal microbiota composition could promote a proinflammatory state in adipose tissue that is associated with obesity and insulin resistance. Our aim was to identify the gut microbiota associated with insulin resistance in appendix samples from morbidly obese patients classified in 2 groups, high (IR-MO) and low insulin-resistant (NIR-MO), and to determine the possible association between these gut microbiota and variables associated with insulin resistance and the expression of genes related to inflammation and macrophage infiltration in adipose tissue. Appendix samples were obtained during gastric bypass surgery and the microbiome composition was determined by 16S rRNA pyrosequencing and bioinformatics analysis by QIIME. The Chao and Shannon indices for each study group suggested similar bacterial richness and diversity in the appendix samples between both study groups. 16S rRNA pyrosequencing showed that the IR-MO group had a significant increase in the abundance of Firmicutes, Fusobacteria, Pseudomonaceae, Prevotellaceae, Fusobacteriaceae, Pseudomonas, Catenibacterium, Prevotella, Veillonella and Fusobacterium compared to the NIR-MO group. Moreover, in the IR-MO group we found a significant positive correlation between the abundance of Prevotella, Succinovibrio, Firmicutes and Veillonella and the visceral adipose tissue expression level of IL6, TNF alpha, ILB1 and CD11b respectively, and significant negative correlations between the abundance of Butyricimonas and Bifidobacterium, and plasma glucose and insulin levels, respectively. In conclusion, an appendix dysbiosis occurs in IR-MO patients, with a loss of butyrate-producing bacteria, essential to maintenance of gut integrity, together with an increase in mucin-degrading bacteria and opportunistic pathogens. The microbiota present in the IR-MO group were related to low grade inflammation in adipose tissue and could be useful for developing strategies to control the development of insulin resistance.

Probiotics and Innate and Adaptive Immune Responses in Premature Infants

Premature infants are at increased risk for morbidity and mortality due to necrotizing enterocolitis (NEC) and sepsis. Probiotics decrease the risk of NEC and death in premature infants; however, mechanisms of action are unclear. A wide variety of probiotic species have been evaluated for potential beneficial properties in vitro, in animal models, and in clinical trials of premature infants. Although there is variation by species and even strain, common mechanisms of protection include attenuation of intestinal inflammation, apoptosis, dysmotility, permeability, supplanting other gut microbes through production of bacteriocins, and more effective use of available nutrients. Here, we review the most promising probiotics and what is known about their impact on the innate and adaptive immune response.

Consumption of Bifidobacterium animalis subsp. lactis BB-12 in yogurt reduced expression of TLR-2 on peripheral blood-derived monocytes and pro-inflammatory cytokine secretion in young adults

PURPOSE

Probiotic bacteria modulate immune parameters and inflammatory outcomes. Emerging evidence demonstrates that the matrix used to deliver probiotics may influence the efficacy of probiotic interventions in vivo. The aims of the current study were to evaluate (1) the effect of one species, Bifidobacterium animalis subsp. lactis BB-12 at a dose of log10 ± 0.5 CFUs/day on immune responses in a randomized, partially blinded, 4-period crossover, free-living study, and (2) whether the immune response to BB-12 differed depending on the delivery matrix.

METHODS

Healthy adults (n = 30) aged 18-40 years were recruited and received four treatments in a random order: (A) yogurt smoothie alone; smoothie with BB-12 added (B) before or (C) after yogurt fermentation, or (D) BB-12 given in capsule form. At baseline and after each 4-week treatment, peripheral blood mononuclear cells (PBMCs) were isolated, and functional and phenotypic marker expression was assessed.

RESULTS

BB-12 interacted with peripheral myeloid cells via Toll-like receptor 2 (TLR-2). The percentage of CD14⁺HLA-DR⁺ cells in peripheral blood was increased in male participants by all yogurt-containing treatments compared to baseline (p = 0.0356). Participants who consumed yogurt smoothie with BB-12 added post-fermentation had significantly lower expression of TLR-2 on CD14⁺HLA-DR⁺ cells (p = 0.0186) and reduction in TNF-α secretion from BB-12- (p = 0.0490) or LPS-stimulated (p = 0.0387) PBMCs compared to baseline.

CONCLUSIONS

These findings not only demonstrate a potential anti-inflammatory effect of BB-12 in healthy adults, but also indicate that the delivery matrix influences the immunomodulatory properties of BB-12.

Host lysozyme-mediated lysis of Lactococcus lactis facilitates delivery of colitis-attenuating superoxide dismutase to inflamed colons

Beneficial microbes that target molecules and pathways, such as oxidative stress, which can negatively affect both host and microbiota, may hold promise as an inflammatory bowel disease therapy. Prior work showed that a five-strain fermented milk product (FMP) improved colitis in T-bet(-/-) Rag2(-/-) mice. By varying the number of strains used in the FMP, we found that Lactococcus lactis I-1631 was sufficient to ameliorate colitis. Using comparative genomic analyses, we identified genes unique to L. lactis I-1631 involved in oxygen respiration. Respiration of oxygen results in reactive oxygen species (ROS) generation. Also, ROS are produced at high levels during intestinal inflammation and cause tissue damage. L. lactis I-1631 possesses genes encoding enzymes that detoxify ROS, such as superoxide dismutase (SodA). Thus, we hypothesized that lactococcal SodA played a role in attenuating colitis. Inactivation of the sodA gene abolished L. lactis I-1631's beneficial effect in the T-bet(-/-) Rag2(-/-) model. Similar effects were obtained in two additional colonic inflammation models, Il10(-/-) mice and dextran sulfate sodium-treated mice. Efforts to understand how a lipophobic superoxide anion (O2 (-)) can be detoxified by cytoplasmic lactoccocal SodA led to the finding that host antimicrobial-mediated lysis is a prerequisite for SodA release and SodA's extracytoplasmic O2 (-) scavenging. L. lactis I-1631 may represent a promising vehicle to deliver antioxidant, colitis-attenuating SodA to the inflamed intestinal mucosa, and host antimicrobials may play a critical role in mediating SodA's bioaccessibility.

Interleukin-10 gene-carrying bifidobacteria ameliorate murine ulcerative colitis by regulating regulatory T cell/T helper 17 cell pathway

Ulcerative colitis (UC) is a chronic inflammatory bowel disease suggested to be closely related to the imbalance of regulatory T cell/T helper 17 cell (Treg/Th17) signaling. Previously, we constructed an interleukin-10 (IL-10) expression vector, BL-hIL-10, and proved that it ameliorates dextran sulfate sodium-induced intestinal inflammation in mice. In this study, we further explored the mechanisms underlying BL-hIL-10 treatment from the Treg/Th17 imbalance perspective. Our results showed that the oral administration of BL-hIL-10 reduced the UC inflammation in mice significantly, which was assessed by disease activity index, spleen index, and pathological changes in colon tissue. Moreover, the mice after BL-hIL-10 treatment had increased proportion of Treg cells while Th17 cells decreased greatly, leading to the reconstruction of Treg/Th17 balance. Furthermore, the Th17 cell-secreted factors, such as IL-6, IL-17, and IL-23, were reduced, but the Treg-related factors, IL-10 and Transforming growth factor-β1 (TGF-β1), were elevated accordingly. Finally, Western blot confirmed the inhibition of nuclear hypoxia-inducible factor-1α (HIF-1α) and cytoplasmic mechanistic target of rapamycin (mTOR) and signal transducer and activator of transcription 3 (STAT3) in intestinal tissues. In conclusion, oral administration of BL-hIL-10 can alleviate the inflammation responses of UC in murine model through the restoration of Treg/Th17 imbalance, which might be at least partially due to the inhibition of hypoxia-mTOR-HIF-1α-Th17 axis as well as IL-6-STAT3-HIF-1α-Th17 pathway.

Gazing into the crystal ball: future considerations for ensuring sustained growth of the functional food and nutraceutical marketplace

Over the last decade the concept of functional foods and nutraceuticals (FFN) has gained support from various stakeholders including the food industry, scientific and academic community, government institutions or regulators, producers and consumers. However, as one begins to evaluate the global FFN industry, several issues emerge including (i) a lack of consensus across jurisdictions for acknowledging safe and efficacious FFN, (ii) challenges regarding the classification of novel food-derived bioactives as FFN or drugs, and (iii) a disconnect between nutrient requirements and dosages of FFN required to facilitate health benefits. The objectives of the present review are to discuss the role of existing stakeholders within the FFN marketplace and identify performance indicators for growth within the FFN sector. In addition, the following report provides feasible resolutions to present and future challenges facing the global FFN industry to ensure sustained long-term growth.

Gut microbiota in children with type 1 diabetes differs from that in healthy children: a case-control study

BACKGROUND

A recent study using a rat model found significant differences at the time of diabetes onset in the bacterial communities responsible for type 1 diabetes modulation. We hypothesized that type 1 diabetes in humans could also be linked to a specific gut microbiota. Our aim was to quantify and evaluate the difference in the composition of gut microbiota between children with type 1 diabetes and healthy children and to determine the possible relationship of the gut microbiota of children with type 1 diabetes with the glycemic level.

METHODS

A case-control study was carried out with 16 children with type 1 diabetes and 16 healthy children. The fecal bacteria composition was investigated by polymerase chain reaction-denaturing gradient gel electrophoresis and real-time quantitative polymerase chain reaction.

RESULTS

The mean similarity index was 47.39% for the healthy children and 37.56% for the children with diabetes, whereas the intergroup similarity index was 26.69%. In the children with diabetes, the bacterial number of Actinobacteria and Firmicutes, and the Firmicutes to Bacteroidetes ratio were all significantly decreased, with the quantity of Bacteroidetes significantly increased with respect to healthy children. At the genus level, we found a significant increase in the number of Clostridium, Bacteroides and Veillonella and a significant decrease in the number of Lactobacillus, Bifidobacterium, Blautia coccoides/Eubacterium rectale group and Prevotella in the children with diabetes. We also found that the number of Bifidobacterium and Lactobacillus, and the Firmicutes to Bacteroidetes ratio correlated negatively and significantly with the plasma glucose level while the quantity of Clostridium correlated positively and significantly with the plasma glucose level in the diabetes group.

CONCLUSIONS

This is the first study showing that type 1 diabetes is associated with compositional changes in gut microbiota. The significant differences in the number of Bifidobacterium, Lactobacillus and Clostridium and in the Firmicutes to Bacteroidetes ratio observed between the two groups could be related to the glycemic level in the group with diabetes. Moreover, the quantity of bacteria essential to maintain gut integrity was significantly lower in the children with diabetes than the healthy children. These findings could be useful for developing strategies to control the development of type 1 diabetes by modifying the gut microbiota.

Nutritional and probiotic supplementation in colitis models

In vitro and animals models have long been used to study human diseases and identify novel therapeutic approaches that can be applied to combat these conditions. Ulcerative colitis and Crohn's disease are the two main entities of inflammatory bowel disease (IBD). There is an intricate relationship between IBD features in human patients, in vitro and animal colitis models, mechanisms and possible therapeutic approaches in these models, and strategies that can be extrapolated and applied in humans. Malnutrition, particularly protein-energy malnutrition and vitamin and micronutrient deficiencies, as well as dysregulation of the intestinal microbiota, are common features of IBD. Based on these observations, dietary supplementation with essential nutrients known to be in short supply in the diet in IBD patients and with other molecules believed to provide beneficial anti-inflammatory effects, as well as with probiotic organisms that stimulate immune functions and resistance to infection has been tested in colitis models. Here we review current knowledge on nutritional and probiotic supplementation in in vitro and animal colitis models. While some of these strategies require further fine-tuning before they can be applied in human IBD patients, their intended purpose is to prevent, delay or treat disease symptoms in a non-pharmaceutical manner.

Anti-inflammatory effects of Lacto-Wolfberry in a mouse model of experimental colitis

AIM: To investigate the anti-inflammatory properties of Lacto-Wolfberry (LWB), both in vitro and using a mouse model of experimental colitis.

METHODS: The effects of LWB on lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) and interleukin (IL)-6 secretion were assessed in a murine macrophage cell line. in vitro assessment also included characterizing the effects of LWB on the activation of NF-E2 related 2 pathway and inhibition of tumor necrosis factor-α (TNF-α)-induced nuclear factor-κB (NF-κB) activation, utilizing reporter cell lines. Following the in vitro assessment, the anti-inflammatory efficacy of an oral intervention with LWB was tested in vivo using a preclinical model of intestinal inflammation. Multiple outcomes including body weight, intestinal histology, colonic cytokine levels and anti-oxidative measures were investigated.

RESULTS: LWB reduced the LPS-mediated induction of ROS production [+LPS vs 1% LWB + LPS, 1590 ± 188.5 relative luminescence units (RLU) vs 389 ± 5.9 RLU, P < 0.001]. LWB was more effective than wolfberry alone in reducing LPS-induced IL-6 secretion in vitro (wolfberry vs 0.5% LWB, 15% ± 7.8% vs 64% ± 5%, P < 0.001). In addition, LWB increased reporter gene expression via the anti-oxidant response element activation (wolfberry vs LWB, 73% ± 6.9% vs 148% ± 28.3%, P < 0.001) and inhibited the TNF-α-induced activation of the NF-κB pathway (milk vs LWB, 10% ± 6.7% vs 35% ± 3.3%, P < 0.05). Furthermore, oral supplementation with LWB resulted in a reduction of macroscopic (-LWB vs +LWB, 5.39 ± 0.61 vs 3.66 ± 0.59, P = 0.0445) and histological scores (-LWB vs +LWB, 5.44 ± 0.32 vs 3.66 ± 0.59, P = 0.0087) in colitic mice. These effects were associated with a significant decrease in levels of inflammatory cytokines such as IL-1β (-LWB vs +LWB, 570 ± 245 μg/L vs 89 ± 38 μg/L, P = 0.0106), keratinocyte-derived chemokine/growth regulated protein-α (-LWB vs +LWB, 184 ± 49 μg/L vs 75 ± 20 μg/L, P = 0.0244), IL-6 (-LWB vs +LWB, 318 ± 99 μg/L vs 117 ± 18 μg/L, P = 0.0315) and other pro-inflammatory proteins such as cyclooxygenase-2 (-LWB vs +LWB, 0.95 ± 0.12 AU vs 0.36 ± 0.11 AU, P = 0.0036) and phosphorylated signal transducer and activator of transcription-3 (-LWB vs +LWB, 0.51 ± 0.15 AU vs 0.1 ± 0.04 AU, P = 0.057). Moreover, antioxidant biomarkers, including expression of gene encoding for the glutathione peroxidase, in the colon and the plasma anti-oxidant capacity were significantly increased by supplementation with LWB (-LWB vs +LWB, 1.2 ± 0.21 mmol/L vs 2.1 ± 0.19 mmol/L, P = 0.0095).

CONCLUSION: These results demonstrate the anti-inflammatory properties of LWB and suggest that the underlying mechanism is at least in part due to NF-κB inhibition and improved anti-oxidative capacity.

Probiotic factors partially prevent changes to caspases 3 and 7 activation and transepithelial electrical resistance in a model of 5-fluorouracil-induced epithelial cell damage

The potential efficacy of a probiotic-based preventative strategy against intestinal mucositis has yet to be investigated in detail. We evaluated supernatants (SN) from Escherichia coli Nissle 1917 (EcN) and Lactobacillus rhamnosus GG (LGG) for their capacity to prevent 5-fluorouracil (5-FU)-induced damage to intestinal epithelial cells. A 5-day study was performed. IEC-6 cells were treated daily from days 0 to 3, with 1 mL of PBS (untreated control), de Man Rogosa Sharpe (MRS) broth, tryptone soy roth (TSB), LGG SN, or EcN SN. With the exception of the untreated control cells, all groups were treated with 5-FU (5 μM) for 24 h at day 3. Transepithelial electrical resistance (TEER) was determined on days 3, 4, and 5, while activation of caspases 3 and 7 was determined on days 4 and 5 to assess apoptosis. Pretreatment with LGG SN increased TEER (p < 0.05) compared to controls at day 3. 5-FU administration reduced TEER compared to untreated cells on days 4 and 5. Pretreatment with MRS, LGG SN, TSB, and EcN SN partially prevented the decrease in TEER induced by 5-FU on day 4, while EcN SN also improved TEER compared to its TSB vehicle control. These differences were also observed at day 5, along with significant improvements in TEER in cells treated with LGG and EcN SN compared to healthy controls. 5-FU increased caspase activity on days 4 and 5 compared to controls. At day 4, cells pretreated with MRS, TSB, LGG SN, or EcN SN all displayed reduced caspase activity compared to 5-FU controls, while both SN groups had significantly lower caspase activity than their respective vehicle controls. Caspase activity in cells pretreated with MRS, LGG SN, and EcN SN was also reduced at day 5, compared to 5-FU controls. We conclude that pretreatment with selected probiotic SN could prevent or inhibit enterocyte apoptosis and loss of intestinal barrier function induced by 5-FU, potentially forming the basis of a preventative treatment modality for mucositis.

Oral administration of Lactobacillus plantarum K68 ameliorates DSS-induced ulcerative colitis in BALB/c mice via the anti-inflammatory and immunomodulatory activities

Many different kinds of fermented food are consumed daily in Taiwan, such as stinky tofu, suan-tsai, and fu-tsai. We have previously reported the diversity of lactic acid bacteria (LAB) at different stages of fermentation in the production of suan-tsai and fu-tsai. In this study, the anti-inflammatory and immunomodulatory activities of Lactobacillus plantarum K68 (K68) isolated from fu-tsai were evaluated. K68 significantly inhibited the production of tumor necrosis factor-α (TNF-α) and prostaglandin E(2) (PGE(2)) in lipopolysaccharide (LPS)-induced murine macrophage RAW 264.7 cells and stimulated interferon-γ (IFN-γ) production in human peripheral blood mononuclear cells (hPBMCs). Additionally, orally administered K68 ameliorated dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in BALB/c mice. Both the disease activity index (DAI) and histological scores (HIS) showed that the severity of UC was significantly reduced by oral administration of K68. Furthermore, the production of pro inflammatory cytokines TNF-α, interleukin-1β (IL-1β), and interleukin-6 (IL-6) was significantly reduced in K68-administered group. Colonic mRNA expression levels of TNF-α, cyclooxygenase-2 (COX-2), forkhead box P3 (Foxp3), suppressors of cytokine signaling 3 (SOCS3), and toll like receptor 4 (TLR4), were also reduced in the K68-administered group. These results suggest that K68 exhibits anti-inflammatory and immunomodulatory activities that ameliorate DSS-induced experimental colitis.

Gut microbiota interactions with obesity, insulin resistance and type 2 diabetes: did gut microbiote co-evolve with insulin resistance?

PURPOSE OF REVIEW

The prevalence of obesity, insulin resistance and type 2 diabetes has steadily increased in the last decades. In addition to the genetic and environmental factors, gut microbiota may play an important role in the modulation of intermediary phenotypes leading to metabolic disease.

RECENT FINDINGS

Obesity and type 2 diabetes are associated with specific changes in gut microbiota composition. The mechanisms underlying the association of specific gut microbiota and metabolic disease include increasing energy harvest from the diet, changes in host gene expression, energy expenditure and storage, and alterations in gut permeability leading to metabolic endotoxemia, inflammation and insulin resistance. In some studies, the modifications of gut microbiota induced by antibiotics, prebiotics and probiotics led to improved inflammatory activity in parallel to amelioration of insulin sensitivity and decreased adiposity. However, these effects were mainly observed in animal models. Their extrapolation to humans awaits further studies.

SUMMARY

The fascinating role of gut microbiota on metabolic disease opens new avenues in the treatment of obesity, insulin resistance and type 2 diabetes. A co-evolutionary clue for microbiota and insulin resistance is suggested.