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This study focused on the mechanisms that fatty acid conjugating strains - Bifidobacterium breve NCIMB 702258 and Bifidobacterium breve DPC 6330 - influence lipid metabolism when ingested with α-linolenic acid (ALA) enriched diet. Four groups of BALB/c mice received ALA enriched diet (3% (w/w)) either alone or in combination with B. breve NCIMB 702258 or B. breve DPC 6330 (109 CFU/day) or unsupplemented control diet for six weeks. The overall n-3 PUFA score was increased in all groups receiving the ALA enriched diet. Hepatic peroxisomal beta oxidation increased following supplementation of the ALA enriched diet with B. breve (P c9t11 conjugated linoleic acid (CLA) was identified in adipose tissue. Furthermore, a strain specific effect of B. breve NCIMB 702258 was found on the endocannabinoid system (ECS). Liver triglycerides (TAG) were reduced following ALA supplementation, compared with unsupplemented controls (P B. breve further reduced liver TAG (P n-3 PUFA score and the ECS.

Probiotic bacteria have been associated with a reduction in cardiovascular disease risk, a leading cause of death and disability.The aim of this study was to assess the impact of dietary administration of exopolysaccharide-producing probiotic Lactobacillus cultures on lipid metabolism and gut microbiota in apolipoprotein E (apoE)-deficient mice.First, we examined lipid metabolism in response to dietary supplementation with recombinant β-glucan-producing Lactobacillus paracasei National Food Biotechnology Centre (NFBC) 338 expressing the glycosyltransferase (Gtf) gene from Pediococcus parvulus 2.6 (GTF), and naturally exopolysaccharide-producing Lactobacillus mucosae Dairy Product Culture Collection (DPC) 6426 (DPC 6426) compared with the non-β-glucan-producing isogenic control strain Lactobacillus paracasei NFBC 338 (PNZ) and placebo (15% wt:vol trehalose). Second, we examined the effects on the gut microbiota of dietary administration of DPC 6426 compared with placebo. Probiotic Lactobacillus strains at 1 × 10(9) colony-forming units/d per animal were administered to apoE(-/-) mice fed a high-fat (60% fat)/high-cholesterol (2% wt:wt) diet for 12 wk. At the end of the study, aortic plaque development and serum, liver, and fecal variables involved in lipid metabolism were analyzed, and culture-independent microbial analyses of cecal content were performed.Total cholesterol was reduced in serum (P0.001; ∼33-50%) and liver (P0.05; ∼30%) and serum triglyceride concentrations were reduced (P0.05; ∼15-25%) in mice supplemented with GTF or DPC 6426 compared with the PNZ or placebo group, respectively. In addition, dietary intervention with GTF led to increased amounts of fecal cholesterol excretion (P0.05) compared with all other groups. Compositional sequencing of the gut microbiota revealed a greater prevalence of Porphyromonadaceae (P = 0.001) and Prevotellaceae (P = 0.001) in the DPC 6426 group and lower proportions of Clostridiaceae (P0.05), Peptococcaceae (P0.001), and Staphylococcaceae (P0.01) compared with the placebo group.Ingestion of exopolysaccharide-producing lactobacilli resulted in seemingly favorable improvements in lipid metabolism, which were associated with changes in the gut microbiota of mice.

peer-reviewed The aim of this study was to investigate if dietary administration of γ-aminobutyric acid (GABA)-producing Lactobacillus brevis DPC 6108 and pure GABA exert protective effects against the development of diabetes in streptozotocin (STZ)-induced diabetic Sprague Dawley rats. In a first experiment, healthy rats were divided in 3 groups (n=10/group) receiving placebo, 2.6 mg/kg body weight (bw) pure GABA or L. brevis DPC 6108 (~109microorganisms). In a second experiment, rats (n=15/group) were randomised to five groups and four of these received an injection of STZ to induce type 1 diabetes. Diabetic and non-diabetic controls received placebo [4% (w/v) yeast extract in dH2O], while the other three diabetic groups received one of the following dietary supplements: 2.6 mg/kg bw GABA (low GABA), 200 mg/kg bw GABA (high GABA) or ~109 L. brevis DPC 6108. L. brevis DPC 6108 supplementation was associated with increased serum insulin levels (P0.05), compared with non-diabetic controls while all other diabetic groups displayed reduced diversity (P

The gut microbiota is a complex ecosystem consisting of a diverse population of prokaryotes that has a symbiotic relationship with its host; thus it plays a vital role for the host's health. Our understanding of the effect of the gut microbiome in health and disease has grown substantially over the past 2 decades, mostly because of recent advances in sequencing and other high-throughput technologies. Given its high metabolic potential, close proximity to the intestinal mucosa, and interaction with the immune system, it is not surprising that the gut microbiome is an important partaker in human health. Evidence to the importance of the gut microbiome in human health and disease is the growing number of conditions now linked to changes in the resident gut microbiota, including recurrent Clostridium difficile infections, inflammatory bowel disease, irritable bowel syndrome, colorectal cancer, allergies, neurological diseases, and metabolic diseases. Research into this field of the association of the gut microbiome with health and disease continues to expand at a rapid pace as we come to accept the gut microbiome as our "second genome." Targeting the gut microbiome to restore/modulate its composition with the use of antibiotics, probiotics, prebiotics, and even fecal microbiota transplantation is considered a promising future strategy for the development of new solutions in the treatment of various diseases associated with an imbalance in microbiota composition and functioning.

The infant gut microbiota undergoes dramatic changes during the first 2 years of life. The acquisition and development of this population can be influenced by numerous factors, and antibiotic treatment has been suggested as one of the most significant. Despite this, however, there have been relatively few studies which have investigated the short-term recovery of the infant gut microbiota following antibiotic treatment. The aim of this study was to use high-throughput sequencing (employing both 16S rRNA and rpoB -specific primers) and quantitative PCR to compare the gut microbiota of nine infants who underwent parenteral antibiotic treatment with ampicillin and gentamicin (within 48 h of birth), 4 and 8 weeks after the conclusion of treatment, relative to that of nine matched healthy controls. The investigation revealed that the gut microbiota of the antibiotic-treated infants had significantly higher proportions of Proteobacteria ( P = 0.0049) and significantly lower proportions of Actinobacteria ( P = 0.00001) (and the associated genus Bifidobacterium [ P = 0.0132]) as well as the genus Lactobacillus ( P = 0.0182) than the untreated controls 4 weeks after the cessation of treatment. By week 8, the Proteobacteria levels remained significantly higher in the treated infants ( P = 0.0049), but the Actinobacteria , Bifidobacterium , and Lactobacillus levels had recovered and were similar to those in the control samples. Despite this recovery of total Bifidobacterium numbers, rpoB -targeted pyrosequencing revealed that the number of different Bifidobacterium species present in the antibiotic-treated infants was reduced. It is thus apparent that the combined use of ampicillin and gentamicin in early life can have significant effects on the evolution of the infant gut microbiota, the long-term health implications of which remain unknown.

Background: We previously showed that microbial metabolism in the gut influences the composition of bioactive fatty acids in host adipose tissue. Objective: This study compared the effect of dietary supplementation for 8 wk with human-derived Bifidobacterium breve strains on fat distribution and composition and the composition of the gut microbiota in mice. Methods: C57BL/6 mice (n = 8 per group) received B. breve DPC 6330 or B. breve NCIMB 702258 (10 9 microorganisms) daily for 8 wk or no supplement (controls). Tissue fatty acid composition was assessed by gas-liquid chromatography while 16S rRNA pyrosequencing was used to investigate microbiota composition. Results: Visceral fat mass and brain stearic acid, arachidonic acid, and DHA were higher in mice supplemented with B. breve NCIMB 702258 than in mice in the other 2 groups (P , 0.05). In addition, both B. breve DPC 6330 and B. breve NCIMB 702258 supplementation resulted in higher propionate concentrations in the cecum than did no supplementation (P , 0.05). Compositional sequencing of the gut microbiota showed a tendency for greater proportions of Clostridiaceae (25%, 12%, and 18%; P = 0.08) and lower proportions of Eubacteriaceae (3%, 12%, and 13%; P = 0.06) in mice supplemented with B. breve DPC 6330 than in mice supplemented with B. breve NCIMB 702258 and unsupplemented controls, respectively. Conclusion: The response of fatty acid metabolism to administration of bifidobacteria is strain-dependent, and strain-strain differences are important factors that influence modulation of the gut microbial community by ingested microorganisms. Am J Clin Nutr 2012;95:1278‐87.

The overall purpose of this study was to examine the lactobacilli and bifidobacteria microbiota in the human ileum at a very early stage of life. Ileostomy effluents from two infants, taken at different time points, were plated on Lactobacillus selective agar and cys-MRS containing mupirocin to select for bifidobacteria. In one case, a stool sample following ileostomy reversal was subsequently analyzed microbiologically. Pulse-field gel electrophoresis and 16S rRNA sequencing was used to investigate the cultivable population of bifidobacteria and lactobacilli and denaturing gradient gel electrophoresis (DGGE) to examine the non-cultivable population. The probiotic strain, Lactobacillus paracasei NFBC 338, was recovered at both time points from one of the infants and dominated in the small intestine for a period of over 3 weeks. Moreover, the probiotic strain, B. animalis subsp. lactis Bb12, was obtained from the other infant. This study shows the presence of two known probiotic strains in the upper intestinal tract at an early stage of human life and thus provides some evidence for their ability to colonize the infant small intestine.

The objective of this study was to investigate the cultivable Lactobacillus population in adult and infant faecal material to identify strains shared across a number of individuals. A range of lactobacilli isolated on Lactobacillus-selective agar from faeces of 16 infants and 11 adults were genetically fingerprinted and further characterized by 16S rRNA gene sequencing. The relatedness of all the Lactobacillus strains isolated to known species was also determined both genetically and phenotypically. This study revealed that the human intestine is initially colonized by only a few (1-2) different cultivable strains whereas in adults the pattern becomes more complex with a higher diversity of strains. The adult samples contained three genetically distinct Lactobacillus strains in some cases, while infant samples generally harboured only one dominant Lactobacillus strain. Moreover, the species in general appeared to differ with Lactobacillus rhamnosus and Lactobacillus casei/paracasei found mainly in adults, whereas Lactobacillus gasseri and Lactobacillus salivarius were more commonly isolated in infant samples. The data reaffirm the differences in Lactobacillus populations both between individual subjects and between the infant and adult, with an overall change in the diversity and complexity from early stages of life to adulthood.

We have previously demonstrated that oral administration of a metabolically activeBifidobacterium brevestrain, with ability to formcis-9,trans-11 conjugated linoleic acid (CLA), resulted in modulation of the fatty acid composition of the host, including significantly elevated concentrations ofc9,t11 CLA and omega-3 (n-3) fatty acids in liver and adipose tissue. In this study, we investigated whether a recombinant lactobacillus expressing linoleic acid isomerase (responsible for production oft10,c12 CLA) fromPropionibacterium acnes(PAI) could influence the fatty acid composition of different tissues in a mouse model. Linoleic-acid-supplemented diets (2 %, w/w) were fed in combination with either a recombinantt10,c12 CLA-producingLactobacillus paracaseiNFBC 338 (Lb338), or an isogenic (vector-containing) control strain, to BALB/c mice for 8 weeks. A third group of mice received linoleic acid alone (2 %, w/w). Tissue fatty acid composition was assessed by GLC at the end of the trial. Ingestion of the strain expressing linoleic acid isomerase was associated with a 4-fold increase (Pt10,c12 CLA in adipose tissues of the mice when compared with mice that received the isogenic non-CLA-producing strain. The livers of the mice that received the recombinant CLA-producing Lb338 also contained a 2.5-fold (albeit not significantly) higher concentration oft10,c12 CLA, compared to the control group. These data demonstrate that a single gene (encoding linoleic acid isomerase) expressed in an intestinal microbe can influence the fatty acid composition of host fat.

Recently, we reported that administration of Bifidobacteria resulted in increased concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in murine adipose tissue [1]. The objective of this study was to assess the impact of co-administration of Bifidobacterium breve NCIMB 702258 and the substrate for EPA, alpha-linolenic acid, on host fatty acid composition. alpha-Linolenic acid-supplemented diets (1%, wt/wt) were fed to mice (n = 8), with or without B. breve NCIMB 702258 (daily dose of 10(9) microorganisms) for 8 weeks. Two further groups received either supplement of B. breve alone or unsupplemented diet. Tissue fatty acid composition was assessed by gas liquid chromatography. Dietary supplementation of alpha-linolenic acid resulted in higher (P < 0.05) alpha-linolenic acid and EPA concentrations in liver and adipose tissue and lower (P < 0.05) arachidonic acid in liver, adipose tissue and brain compared with mice that did not receive alpha-linolenic acid. Supplementation with B. breve NCIMB 702258 in combination with alpha-linolenic acid resulted in elevated (P < 0.05) liver EPA concentrations compared with alpha-linolenic acid supplementation alone. Furthermore, the former group had higher (P < 0.05) DHA in brain compared with the latter group. These results suggest a role for interactions between fatty acids and commensals in the gastrointestinal tract. This interaction between administered microbes and fatty acids could result in a highly effective nutritional approach to the therapy of a variety of inflammatory and neurodegenerative conditions.