Lactobacillus Group Research Articles

Lactobacillus Aggravate Bile Duct Ligation-Induced Liver Inflammation and Fibrosis in Mice

Lactobacillus (LAB) have been reported to exert both harmful and beneficial effects on human and animal health. Recently, it has been reported that dysbiosis and bacterial translocation contribute to liver fibrosis. However, the role of Gram-positive LAB in the situation of chronic liver diseases has not been yet elucidated. Liver injury was induced by bile duct ligation (BDL) in LAB or control-administered mice. Liver fibrosis was enhanced in LAB-administered mice compared with control-treated mice as demonstrated by quantification of Sirius-red positive area, hydroxyproline contents and fibrosis-related genes (Col1α1, Acta2, Timp1, Tgfb1). Moreover, LAB-administered mice were more susceptible to BDL-induced liver injury as shown by increased ALT and AST level of LAB group compared with control group at 5 days post BDL. Consistent with serum level, inflammatory cytokines (TNF-α, IL-6 and IL-1β) were also significantly increased in LAB-treated mice. Of note, LAB-treated liver showed increased lipoteichoic acid (LTA) expression compared with control-treated liver, indicating that LAB-derived LTA may translocate from intestine to liver via portal vein. Indeed, responsible receptor or inflammatory factor (PAFR and iNOS) for LTA were upregulated in LAB-administered group. The present findings demonstrate that administration of LAB increases LTA translocation to liver and induces profibrogenic inflammatory milieu, leading to aggravation of liver fibrosis. The current study provides new cautious information of LAB for liver fibrosis patients to prevent the detrimental effect of LAB supplements.

Statistical evaluation of beer spoilage bacteria by real-time PCR analyses from 2010 to 2016

A total of 13,802 samples over seven years were investigated using real-time PCR for the presence of beer spoilage bacteria, providing a rare large-scale overview of the incidence of individual species. At the same time, the isolation site (early stages of the brewing process = type I and late stages = type II) and the type of contaminated beer and intermediate products (bottom-fermented or top-fermented) were evaluated using chi-squared analysis. The most frequently occurring species were Lactobacillus brevis (7 year average 41.9%), Lactobacillus (para-)casei (10.4%) and Lactobacillus backii (9.5%). L. (para-)casei was found at significantly higher rates in the early stages of the brewing process, whereas Lactobacillus lindneri, the Lactobacillus [L. (para-)plantarum and L. coryniformis] and the Pectinatus (P. cerevisiiphilus, P. frisingensis and P. haikarae) groups and Megasphaera cerevisiae predominated in the later stages and in package (significance level 95%). On a significance level of 95%, Pediococcus damnosus, M. cerevisiae and L. lindneri together with the Pectinatus and Lactobacillus groups grew predominantly in bottom fermented samples. L. brevis, in contrast, was found most frequently in top fermented beers. Copyright © 2018 The Institute of Brewing & Distilling

Prebiotic index evaluation of crude laminaran of Sargassum sp. using feces of wistar rats

Today, prebiotics are often added to food. This compound is a food substance which could not be digested, yet benefiting the host by selectively stimulating the growth or activity of one or more bacteria in the colon to improve the health of the host. One of the foodstuffs derived from algae, which could not be digested is laminaran (β-Glucan). The relationship between microflora with the added prebiotics was tested by measuring their prebiotic index, which is supported by total sugars and laminaran levels. The results showed that total sugar content of Laminaran Acid Extract (LAE) (9.075 %) was higher than that of Laminaran Modified Extract (LME) (7.355 %), while the laminaran level of LME (42.23 %) was higher than that of LAE (30.92 %). HPLC test result confirmed the presence of laminaran. The obtained prebiotic index values of LAE and LME were 1.29 and 2.10, respectively, with a negative index score for LAE prebiotic, yet positive one for LME in terms of probiotic from Lactobacillus group. Laminaran extract, especially LME, deserves to be regarded as a prebiotic candidate.

Gut Microbiota in Human Systemic Lupus Erythematosus and a Mouse Model of Lupus.

Gut microbiota dysbiosis has been observed in a number of autoimmune diseases. However, the role of the gut microbiota in systemic lupus erythematosus (SLE), a prototypical autoimmune disease characterized by persistent inflammation in multiple organs of the body, remains elusive. Here we report the dynamics of the gut microbiota in a murine lupus model, NZB/W F1, as well as intestinal dysbiosis in a small group of SLE patients with active disease. The composition of the gut microbiota changed markedly before and after the onset of lupus disease in NZB/W F1 mice, with greater diversity and increased representation of several bacterial species as lupus progressed from the predisease stage to the diseased stage. However, we did not control for age and the cage effect. Using dexamethasone as an intervention to treat SLE-like signs, we also found that a greater abundance of a group of lactobacilli (for which a species assignment could not be made) in the gut microbiota might be correlated with more severe disease in NZB/W F1 mice. Results of the human study suggest that, compared to control subjects without immune-mediated diseases, SLE patients with active lupus disease possessed an altered gut microbiota that differed in several particular bacterial species (within the genera Odoribacter and Blautia and an unnamed genus in the family Rikenellaceae) and was less diverse, with increased representation of Gram-negative bacteria. The Firmicutes/Bacteroidetes ratios did not differ between the SLE microbiota and the non-SLE microbiota in our human cohort.IMPORTANCE SLE is a complex autoimmune disease with no known cure. Dysbiosis of the gut microbiota has been reported for both mice and humans with SLE. In this emerging field, however, more studies are required to delineate the roles of the gut microbiota in different lupus-prone mouse models and people with diverse manifestations of SLE. Here, we report changes in the gut microbiota in NZB/W F1 lupus-prone mice and a group of SLE patients with active disease.

Remodelled Water Adjusted Both Proportion of Intestinal Flora and Peripheral Leukocyte Subset

Around 60% of the body weight consisted with water. So we tried to characterize the quality of the water for human physical factors. Lots of fundamental and clinical studies reported that many kind of water plays an important role in the physiological maintenance of humans as well as animals. This report was design to assess the influence of administration by remodeled water (RMW) on the development of physiological functions in human and experimental animal model. RMW was different from many other water, different from molecule itsself. RMW was proved to absorbed human odor molecule in vitro and in vivo. The animal model of experiment by immune-suppressive agent, RMW recovered the function of phagocytic cell in diabetes meritus (DM) model. In a human trial for intestinal model were shown to increased lactobacillus group other than anaerobic bacillus. More about odor factor, RMW decreased main odor elements, ammonia and hydrosulfate to decrease the odor in the exhaustive faces even after 7 days. In case of combat against infectious agent such as foreign microorganism, an active oxygen is most important in phagocytic cell. However excess level of oxygen is some time harmful for self-tissue, requiring to regulate at minimum level. Therefore, digital reliable assessment is necessary in phagocytic cells, not in in vitro system. In this report, we reported such trial by employing RMW.

Inclusion of Bacillus amyloliquefaciens strain TOA5001 in the diet of broilers suppresses the symptoms of coccidiosis by modulating intestinal microbiota.

Coccidiosis is an intestinal parasitic infection and one of the most prevalent and economically damaging diseases of chickens. Furthermore, coccidia-induced mucogenesis promotes secondary colonization by Clostridium perfringens, a major pathogen of chickens that causes necrotic enteritis. Our previous work found that supernatant of a culture of Bacillus amyloliquefaciens strain TOA5001 (BA) inhibited the growth of C. perfringens on Gifu anaerobic broth medium. Accordingly, we evaluated the effectiveness of dietary BA administration in inhibiting C. perfringens colonization of the intestine in broilers that were experimentally infected with coccidia. Ten healthy broilers from a BA-supplemented (2×105 colony-forming units/g of feed) broiler group and 10 from a non-treated group were challenged with Eimeria tenella and E. maxima (5000 oocysts of each species/chick) at 28 days old. At 36 days old, five chicks from each group were slaughtered, whereas the remaining five in each group were killed at 49 days old. Dietary BA administration into Eimeria-challenged birds reduced coccidial symptoms such as intestinal lesions. It also modified the cecal microbiota through suppressing C. perfringens and E.coli colonization, and inducing domination of Faecalibacterium prausnitzii, the Lactobacillus group and unknown Lachnospiraceae genera by bacterial DNA-based metagenome analyses. B. amyloliquefaciens TOA5001 supplementation suppressed the symptoms of coccidiosis by modulating cecal microbiota in Eimeria-challenged broilers.

Streptococcus mutans Displays Altered Stress Responses While Enhancing Biofilm Formation by Lactobacillus casei in Mixed-Species Consortium.

Like Streptococcus mutans, lactobacilli are commonly isolated from carious sites, although their exact role in caries development remains unclear. This study used mixed-species models to analyze biofilm formation by major groups of oral lactobacilli, including L. casei, L. fermentum, L. rhamnosus, L. salivarius ssp. salivarius, and L. gasseri. The results showed that lactobacilli did not form good biofilms when grown alone, although differences existed between different species. When grown together with S. mutans, biofilm formation by L. gasseri and L. rhamnosus was increased by 2-log (P < 0.001), while biofilms by L. fermentum reduced by >1-log (P < 0.001). L. casei enhanced biofilm formation by ~2-log when grown with S. mutans wild-type, but no such effects were observed with S. mutans deficient of glucosyltransferase GtfB and adhesin P1. Both S. mutans and L. casei in dual-species enhanced resistance to acid killing with increases of survival rate by >1-log (P < 0.001), but drastically reduced the survival rates following exposure to hydrogen peroxide (P < 0.001), as compared to the respective mono-species cultures. When analyzed by RNA-seq, more than 134 genes were identified in S. mutans in dual-species with L. casei as either up- or down-regulated when compared to those grown alone. The up-regulated genes include those for superoxide dismutase, NADH oxidase, and members of the mutanobactin biosynthesis cluster. Among the down-regulated genes were those for GtfB and alternative sigma factor SigX. These results further suggest that interactions between S. mutans and oral lactobacilli are species-specific and may have significant impact on cariogenic potential of the community.

Different Intestinal Microbial Profile in Over-Weight and Obese Subjects Consuming a Diet with Low Content of Fiber and Antioxidants.

Obesity has been related to an increased risk of multiple diseases in which oxidative stress and inflammation play a role. Gut microbiota has emerged as a mediator in this interaction, providing new mechanistic insights at the interface between fat metabolism dysregulation and obesity development. Our aim was to analyze the interrelationship among obesity, diet, oxidative stress, inflammation and the intestinal microbiota in 68 healthy adults (29.4% normal-weight). Diet was assessed through a food frequency questionnaire and converted into nutrients and dietary compounds using food composition tables. The intestinal microbiota was assessed by quantitative PCR, fecal short chain fatty acids by gas chromatography and serum biomarkers by standard protocols. Higher levels of malondialdehyde (MDA), C reactive protein (CRP), serum leptin, glucose, fat percentage and the intestinal Lactobacillus group were found in the obese people. Cluster analysis of body mass index, fat mass, glucose, LDL/HDL ratio, leptin, MDA and CRP classified the subjects into two groups. The levels of the intestinal Bacteroides-Prevotella-Porphyromonas group were lower in the cluster and linked to a higher pro-oxidant and pro-inflammatory status, whose individuals also had lower intake of fruits, dried fruits, and fish. These results could be useful for designing strategies targeted to obesity prevention.

Characterization of the peptide fraction from digested Parmigiano Reggiano cheese and its effect on growth of lactobacilli and bifidobacteria

Parmigiano Reggiano (PR) is a raw-milk, hard cooked, long-ripened cheese of high quality and nutritional value. Long ripening times allow for extensive proteolysis of milk proteins to yield a number of peptides, some of which have potential healthy bioactive properties. This study aimed to: i) determine the peptide profile of PR cheese subjected to simulated gastrointestinal transit; ii) evaluate in vitro whether the peptides could support growth of beneficial microbial groups of the gut microbiota. PR samples were subjected to in vitro digestion, simulating oral, gastric, and duodenal transit. Liquid chromatography coupled with tandem mass spectrometry revealed that digestion caused the disappearance of the serum proteins and most of the original peptides, while 71 new peptides were found, all ranging from 2 to 24 residues. The digests were given as sole nitrogen source to pure cultures of Bifidobacterium (27 strains) and Lactobacillus (30 strains), and to bioreactor batch cultures of human gut microbiota. Most of bifidobacteria and lactobacilli grew more abundantly on PR digests than on the control peptone, and exhibited strain- or species-specific peptide preferences, as evidenced by principal component analysis. Bifidobacteria generally consumed a greater amount of peptides than lactobacilli, in terms of both the mean peptide consumption and the number of peptides consumed. For bifidobacteria, peptide preferences were very diverse, but a core of 10 peptides with 4 or 5 residues were consumed by all the strains. Lactobacilli behaved more homogenously and consumed nearly only the same 6 peptides, mostly dipeptides. The peptide preferences of the different groups of bifidobacteria and lactobacilli could not be ascribed to features such as the length of the peptide or the abundance of residues with peculiar properties (hydrophobicity, polarity, charge) and likely depend on specific proteases and/or peptide transporters preferentially recognizing specific sequence motifs. The cultures of human colonic microbiota confirmed that PR digest promoted the growth of commensal bifidobacteria. This study demonstrated that peptides derived from simulated gastrointestinal digestion of PR supported the growth of most lactobacilli and bifidobacteria.

Dynamic gastrointestinal digestion of grape pomace extracts: Bioaccessible phenolic metabolites and impact on human gut microbiota

Grape pomace is a winery by-product rich in polyphenols and dietary fibre, two food constituents in whose bioaccessibility gut microbiota is implicated. To overcome the limitations of in vivo studies concerning difficult access to proximal regions of the colon, this paper reports, for the first time, the in vitro colonic digestion of grape pomace extracts (GPEs) using a dynamic gastrointestinal digestion model. Experiments consisted in the inoculation of the simgi® model with faecal microbiota from healthy volunteers, and further feeding of the system with a single (acute feeding of 700mg) and continuous (chronic feeding of 700mg/day; 14days) dose of GPE. Two independent experiments with faecal microbiota from two volunteers (#1 and #2) were carried out. Results were determined in terms of microbial functionality [phenolic metabolites, short-chain fatty acids (SCFAs) and ammonium ion] and composition (plate counting and qPCR) in the different simgi® compartments (ascending, transverse and descending colon). Different benzoic, phenylacetic and phenylpropionic acids were found as the main bioaccessible phenolic metabolites released from GPE. As an indicator of microbial fermentative activity, a significant increase (p<0.05) in the concentration of SCFAs (acetic, propionic and butyric acids) was observed after chronic feeding (19–54% increase for volunteer #1, and 83–150% increase for volunteer #2). In relation to microbial proteolytic activity, increasing trends in ammonium production (although not significant, p>0.05) were observed during chronic feeding for both experiments. Also, during the chronic feeding, the main bacteria groups increased (p<0.05) in respect to the steady state, with the highest increments being for Lactobacillus and Bacteroides groups. Additionally, a bacteria strain capable of metabolizing (−)-epicatechin gallate, a phenolic compound characteristic of grapes and wine, was isolated from the simgi® stable microbiota and was identified as Raoultella ornithinolytica or Raoultella planticola.

Analysis of microbiota in first episode psychosis identifies preliminary associations with symptom severity and treatment response

The effects of gut microbiota on the central nervous system, along its possible role in mental disorders, have received increasing attention. Here we investigated differences in fecal microbiota between 28 patients with first-episode psychosis (FEP) and 16 healthy matched controls and explored whether such differences were associated with response after up to 12months of treatment. Numbers of Lactobacillus group bacteria were elevated in FEP-patients and significantly correlated with severity along different symptom domains. A subgroup of FEP patients with the strongest microbiota differences also showed poorer response after up to 12months of treatment. The present findings support the involvement of microbiota alterations in psychotic illness and may provide the basis for exploring the benefit of their modulation on treatment response and remission.

Restoration of cefixime-induced gut microbiota changes by Lactobacillus cocktails and fructooligosaccharides in a mouse model

Probiotics have been used to rebuild the antibiotic-induced dysfunction in gut microbiota, but whether the different strains of probiotics result in similar or reverse effects remains unclear. In this study, the different recovery effects of two cocktails (each contains four strains) of Lactobacillus and fructooligosaccharide against cefixime-induced change of gut microbiota were evaluated in C57BL/6J mice. The results show that the use of cefixime caused a reduction in the diversities of the microbial community and led to significantly decreasing to one preponderant Firmicutes phylum, which was difficult to restore naturally in the short term. The gut microbiota compositions of the groups treated with the probiotic cocktails were much more diverse than those of the natural recovery group. The effects of Lactobacillus cocktails against the cefixime-induced gut microbiota change may mainly be due to the beneficial SCFAs production in vivo and also be related to the good cell adhesion properties performed in vitro. Meanwhile, the restoration of the cefixime-induced gut microbiota was significantly different between two Lactobacillus groups since the Lactobacillus strains with high levels of fructooligosaccharide use and better cell adhesion properties performed considerably better than the Lactobacillus strains with high survival rates in the gastrointestinal tract. The contents of short-chain fatty acids in ceca were increased to 26.483±1.925 and 25.609±2.782μmol/g in the two probiotic cocktail groups respectively compared to 15.791±0.833μmol/g (P<0.05) in control group. Moreover, intestinal inflammation was alleviated by administration of the Lactobacillus cocktails. However, fructooligasaccharide administration showed certain effects on gut microbiota restoration (such as an increase of Akkermansia), although its effect on the entire microbiome structure is not so obvious.

The therapeutic effect of probiotics on allergic rhinitis：a Meta analysis

Objective:To systemically review the therapeutic effect of probitics on allergic rhinitis（AR).Method:Literatures about the effect of probitics on AR were searched in PubMed. The Cochrane Library, Web of Science and CNKI, WanFang Data and VIP inception to April 2016,and 2 reviewers independently screened literatures according to the inclusion and exclusion criteria, extracted data, and assessed the risk of bias of included studies. Then meta-analysis was performed using RevMan5.2 software. Result:A total of 16RCTs involving1374 patients were included in the meta-analysis, including 809 cases in the probitic group and 568 cases in the placebo group. The results of meta-analysis showed that the efficacy of probitic group was superior to the placebo group in total RQLQ,nasal RQLQ,eye RQLQ and the serum eosinophil count,the difference was statistically significant ［MD=-4.43,95%CI（-8.65~-0.20）;MD=-1.08，95%CI（-1.89~0.27）;MD=-0.95,95%CI（-1.46~-1.44）;MD=-28.40,95%CI（-43.53~-13.26）］.There was no significant difference in Serum IgE between the probitic group and the placebo group(P>0.05).There was no significant difference in the NTSS value between the lactobacillus group and the bifidobacterium group(P>0.05). Conclusion:Compared to the placebo, probitics can effectively reduce symptom scores of patients with AR;and different strains of probitics indicated no significant differences in improving nasal symptoms.

Lactobacillus intake for 60 days favors antioxidant status of human breast milk: an RCT.

This study aimed to evaluate the effects of lactobacillus supplementation on trends of breast milk antioxidant parameters. In an interventional study, 50 lactating women were randomly allocated to receive a daily supplement of lactobacillus (n=25) or a placebo (n=25) for 60 days. Daily dietary intake, anthropometric measures and breast milk antioxidant parameters were determined at the onset, and days 30 and 60 of the study. Repeated-measures ANOVA were performed to assess the change over time in the anthropometric and biochemical parameters between the two groups. The main effect of treatment was compared by using Bonferroni's procedure for CI adjustment. The significance level was set at p<0.05. There was a significant increase in breast milk total antioxidant capacity (TAC) between onset of study and day 30 (p=0.01) and day 60 (p=0.001) after lactobacillus supplementation; however, breast milk TAC level did not change significantly between days 30 and 60 (p=0.7). In the placebo group, breast milk TAC levels decreased significantly after 60 days (p=0.001). Breast milk malondialdehyde (MDA) levels decreased progressively during the study in the lactobacillus group (p=0.001); however, there was a significant increase in MDA with time in breast milk samples in the placebo group (p=0.015). Based on the findings, lactobacillus supplementation for 60 days could significantly increase breast milk TAC and decrease breast milk MDA levels, compared with baseline; however, further studies are needed to confirm these results.

Mice gut microbiota programming by using the infant food profile. The effect on growth, gut microbiota and the immune system

During the complementary feeding (CF) period, nutritional imbalances can have negative consequences not only on a child's health in the short term but also later in adulthood, as a phenomenon known as "nutritional programming" takes place. The aim of this study was to evaluate the possible changes in body growth, gut microbiota (GM) and the immune system in mice fed with two different commercial sterilized baby foods in jars (BFJs) for CF. Mice fed with different BFJs (A and B groups) showed an accelerated growth from the fifth week of life when compared with the control (C) group. Group A showed a higher BMI, post-weaning growth rate, and IL-10 levels and a decrease in the Lactobacillus group. Group B showed a significant decrease in the total bacterial count, Lactobacillus group, Enterococcus spp. and Bacteroidetes-Prevotella. The Bifidobacterium genus tended to be lower in groups A and B. Akkermansia muciniphila was more frequently detected in group C. The results obtained from groups A and B can be attributed to the BFJ fatty acid profile, rich in UFAs. This study demonstrates for the first time that the commercial BFJ composition during CF might be a "programming" factor for body growth, GM and the immune system.

Dietary resin acid composition as a performance enhancer for broiler chickens

SummaryResin acid composition (RAC) has previously been shown to inhibit the growth of the Gram-positive bacterial species Clostridium perfringens in vitro and to modulate the ileal microbiota of broiler chickens. The following trials examined the effect of RAC on broiler chickens in two experiments. In experiment 1, 1400 one-day-old Ross 308 broilers were divided into two coccidiostat treatments: chemical (CC) and ionophore (IC), which were further divided into two RAC dosages: 0 and 0.5 g/kg. All diets were supplemented with xylanase, β-glucanase and phytase feed enzymes. The birds were raised in a commercial-type environment without additional microbial challenge during the 42-day trial. RAC improved the body weight gain by 3.3% and feed conversion ratio by 5.7% with CC, and improved footpad lesion scores with IC but had no effect on the litter quality. Experiment 2 was a 35-day subclinical necrotic enteritis (NE) challenge trial with 510 male Ross 308 chickens. The dietary treatments included a non-challenged, non-supplemented control and four NE challenged treatments with dietary RAC supplementation at 0, 1, 2, and 3 g/kg. The birds were challenged with Eimeria maxima on day nine and C. perfringens on day 14. While RAC at 1 g/kg significantly increased bird weight gain during the challenge, it did not affect the microbial or short chain fatty acid (SCFA) profiles. In contrast, RAC at 3 g/kg reduced the abundance of the Lactobacillus group and tended to reduce the abundance of genus Bifidobacterium and the total numbers of eubacteria. These experiments suggest that dietary RAC at a moderate dose positively affected broiler performance. However, changes in caecal microbiota populations may not have influenced the observed performance effects of RAC.

Lactobacillus plantarum isolated from kimchi suppress food allergy by modulating cytokine production and mast cells activation

Commensal bacteria interact with mucosal immune or epithelial cells to modulate the immune system. Probiotics have been proposed as a novel preventive or therapeutic method for immunological diseases because of their ability to alter intestinal microflora. Herein, lactobacilli isolated from kimchi were tested for their capacity to modulate intestinal allergy in mice. Lactic acid bacteria suppressed IL-4, IL-5, IL-13, and IL-17A cytokine production in splenocytes from OVA-sensitized mice in vitro. In a mouse model of food allergy, lactobacilli significantly inhibited the expression of Th2-associated gene products such as GATA3, IL-4, IL-5, IL-9, and IL-13 in the small intestine. Moreover, pro-inflammatory cytokine levels were lower in the lactobacillus group. Lactic acid bacteria also modulated mast cell infiltration and activation. Serum IgE/IgG2a and IgG1/IgG2a ratios were altered to alleviate Th2 responses. In conclusion, lactobacilli from kimchi effectively regulated intestinal allergy by suppressing Th2 responses and modulating mast cell function and recruitment.

Enzymatically Modified Starch Favorably Modulated Intestinal Transit Time and Hindgut Fermentation in Growing Pigs.

Aside from being used as stabilizing agents in many processed foods, chemically modified starches may act as functional dietary ingredients. Therefore, development of chemically modified starches that are less digestible in the upper intestinal segments and promote fermentation in the hindgut receives considerable attention. This study aimed to investigate the impact of an enzymatically modified starch (EMS) on nutrient flow, passage rate, and bacterial activity at ileal and post-ileal level. Eight ileal-cannulated growing pigs were fed 2 diets containing 72% purified starch (EMS or waxy cornstarch as control) in a cross-over design for 10 d, followed by a 4-d collection of feces and 2-d collection of ileal digesta. On d 17, solid and liquid phase markers were added to the diet to determine ileal digesta flow for 8 h after feeding. Reduced small intestinal digestion after the consumption of the EMS diet was indicated by a 10%-increase in ileal flow and fecal excretion of dry matter and energy compared to the control diet (P<0.05). Moreover, EMS feeding reduced ileal transit time of both liquid and solid fractions compared to the control diet (P<0.05). The greater substrate flow to the large intestine with the EMS diet increased the concentrations of total and individual short-chain fatty acids (SCFA) in feces (P<0.05). Total bacterial 16S rRNA gene abundance was not affected by diet, whereas the relative abundance of the Lactobacillus group decreased (P<0.01) by 50% and of Enterobacteriaceae tended (P<0.1) to increase by 20% in ileal digesta with the EMS diet compared to the control diet. In conclusion, EMS appears to resemble a slowly digestible starch by reducing intestinal transit and increasing SCFA in the distal large intestine.

The effect of probiotic bacteria (Lactobacillus acidophilus and Bifidobacterium lactis) on the accumulation of lead in rat brains.

Lead is a toxic metal present in different concentrations in a wide variety of food products. Exposure to lead, even to low levels, causes acute and chronic toxicities. Lead can cross the blood-brain barrier and accumulate in the nervous system. Probiotics are live microorganisms that, when used in adequate amounts, confer a health benefit on the host. Although a recent study demonstrated that the studied bacteria have a protective effect against acute lead toxicity, no research has been found that shows the long-term impact of these bacteria in vivo. The current study surveyed the protective effects of two species of probiotics, Lactobacillus acidophilus LA-5 and Bifidobacterium lactis BB-12, that are most widely used in many functional foods against oral lead exposure (4weeks) in rat brains. The results revealed that, at the end of the second week of chronic exposure to lead and probiotic bacteria, the lowest level of lead belonged to the Lactobacillus group. At the end of the fourth week, the lowest amount of lead was related to the group receiving both types of probiotics. With the physiological benefits of probiotic consumption, the bacterial solution in this study did not show high efficacy in reducing brain lead concentrations.

Bioactive compounds from regular diet and faecal microbial metabolites.

Short-chain fatty acids (SCFAs) formation by intestinal bacteria is regulated by many different factors, among which dietary fibre is currently receiving most attention. However, since fibre-rich foods are usually good dietary sources of phenolic compounds, which are also known to affect the microbiota, authors hypothesize that the regular intake of these bioactive compounds could be associated with a modulation of faecal SCFA production by the intestinal microbiota. In this work, food intake was recorded by means of a validated Food Frequency Questionnaire. Fibres were determined using Marlett food composition tables, and phenolic compounds were obtained from Phenol-Explorer Database. Analysis of SCFA was performed by gas chromatography-flame ionization/mass spectrometry and quantification of microbial populations in faeces by quantitative PCR. Klason lignin and its food contributors, as predictors of faecal butyrate production, were directly associated with Bacteroides and Bifidobacterium levels, as well as lignans with Bacteroides. Also, anthocyanidins, provided by strawberries, were associated with faecal propionate and inversely related to Lactobacillus group. These results support the hypothesis we put forward regarding the association between some vegetable foods (strawberries, pasta, lentils, lettuce and olive oil) and faecal SCFA. More studies are needed in order to elucidate whether these associations have been mediated by the bacterial modulatory effect of the bioactive compounds, anthocyanins, lignans or Klason lignin, present in foodstuffs.