ofLactobacillus Acidophilus Research Articles

The Effect Allium sativum (Garlic Extract) as Prebiotic Substance on the Activity of Probiotic Bacteria Lactobacillus acidophilus Against Some Locally Isolates of Pathogenic Bacteria

The aim of this study was to improve the growth and inhibitory activity of the selected Lactobacillus isolate.A total of twenty samples of dairy products (fresh yogurt) were collected. Seven isolates of Lactobacillusspecies . were obtained, and identified as three Lactobacillus fermentum, three Lactobacillus acidophilus andone of Lactobacillus brevis. The growth of lactobacillus acidophilus was counted , also inhibitory activity ofLactobacillus acidophilus against some pathogenic bacteria was tested) for two different incubation periodsbefore the addition of Allium sativum(garlic extract) as prebiotic substances. three different concentrationsof it were used by addition of it toDe Man, Rogosa and Sharpe agar (MRS) medium as prebiotic substances , and two incubation periods(24, 48) hour. The effect of Allium sativum on the growth of probiotic bacteria was evaluated, measurementof Lactobacillus acidophilus growth curve was done after and before adding garlic extract. For analyzinginhibitory activity of Lactobacillus acidophilus with the Allium ,results showed that Lactobacillus acidophiluspropagated in MRS fortified with 20% and 30% v/v garlic extract with incubation period 24 hr by giving thehighest inhibition zone.It was concluded that Lactobacillus.acidophilus isolate can grow well and exhibit good effect against Gramnegative bacteria in a medium containing garlic extract (that is added as a substrate supporting probioticgrowth and activity). also it was clear that filtrate of Lactobacillus .acidophilus isolate that propagatingin spesific broth fortified with 20% garlic extract at 48 hr incubation period produce antibacterial effectbetter than 10% , it was concluded that prebiotic treatment enhance the growth of Lactobacillus acidophilusespecially at 24 hr. this may due to fructooligosaccharide content in garlic , also when propagated in MRSwithout prebiotic treatment, and which may due to highly decrease in pH which cause inhibition the growthof Lactobacillus acidophillus.

In Vivo Transcriptome of Lactobacillus acidophilus and Colonization Impact on Murine Host Intestinal Gene Expression.

Lactobacillus acidophilus NCFM is a probiotic strain commonly used in dairy products and dietary supplements. Postgenome in vitro studies of NCFM thus far have linked potential key genotypes to its probiotic-relevant attributes, including gut survival, prebiotic utilization, host interactions, and immunomodulatory activities. To corroborate and extend beyond previous in vivo and in vitro functional studies, we employed a dual RNA sequencing (RNA-seq) transcriptomic approach to identify genes potentially driving the gut fitness and activities of L. acidophilus NCFM in vivo, and in parallel, examine the ileal transcriptional response of its murine hosts during monocolonization. Spatial expression profiling of NCFM from the ileum through the colon revealed a set of 134 core genes that were consistently overexpressed during gut transit. These in vivo core genes are predominantly involved in the metabolism of carbohydrates, amino acids, and nucleotides, along with mucus-binding proteins and adhesion factors, confirming their functionally important roles in nutrient acquisition and gut retention. Functional characterization of the highly expressed major S-layer-encoding gene established its indispensable role as a cell shape determinant and maintenance of cell surface integrity, essential for viability and probiotic attributes. Host colonization by L. acidophilus resulted in significant downregulation of several proinflammatory cytokines and tight junction proteins. Genes related to redox signaling, mucin glycosylation, and circadian rhythm modulation were induced, suggesting impacts on intestinal development and immune functions. Metagenomic analysis of NCFM populations postcolonization demonstrated the genomic stability of L. acidophilus as a gut transient and further established its safety as a probiotic and biotherapeutic delivery platform.IMPORTANCE To date, our basis for comprehending the probiotic mechanisms of Lactobacillus acidophilus, one of the most widely consumed probiotic microbes, was largely limited to in vitro functional genomic studies. Using a germfree murine colonization model, in vivo-based transcriptional studies provided the first view of how L. acidophilus survives in the mammalian gut environment, including gene expression patterns linked to survival, efficient nutrient acquisition, stress adaptation, and host interactions. Examination of the host ileal transcriptional response, the primary effector site of L. acidophilus, has also shed light into the mechanistic roles of this probiotic microbe in promoting anti-inflammatory responses, maintaining intestinal epithelial homeostasis and modulation of the circadian-metabolic axis in its host.

Effects of Lactobacillus acidophilus and Lactobacillus helveticus on biofilm formation by ESBL-producing uropathogenic Escherichia coli

Background: Uropathogenic E. coli (UPEC) are important clinical pathogens and are considered as one of the major causes of urinary tract infection. Unfortunately, the treatment of UPEC infections is becoming more difficult because isolates are increasingly resistant to commonly used antimicrobial agents. The potential ability of UPEC to form biofilm might explain its outstanding antibiotic resistance and survival properties. Objectives: We aimed to assess the effect of cell free supernatants (CFS) of Lactobacillus acidophilus La-5 and Lactobacillus helveticus B-734 on the ability of ESBL-producing UPEC isolates to form biofilm in vitro and to eradicate the already formed biofilm of UPEC isolates. Methodology: A total of 50 isolates of ESBLproducing UPEC, were recovered from different private laboratories, then subcultured on MacConkey’s medium and identified by conventional microbiological methods. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method and confirmed for ESBL production. The ability of UPEC to produce biofilm was determined using Congo red agar (CRA) method and tissue culture plate (TCP) method. CFS of L.acidophilus La-5 and L. helveticus B-734 were prepared and used to assess its effect on the ability of ESBL-producing UPEC isolates to form biofilm in vitro and the eradicationof the already formed biofilm. Results: Biofilm formation was found in 28% of theisolates. Furthermore, the strong biofilm-forming category was detected in 10% of the isolates, whereas the moderate biofilm-forming category was detected in 18%. CFS of L. acidophilus La-5 was more effective (91.12%) in inhibiting the formation of E. coli biofilm than CFS of L. helveticus B-734 (76.44%), while it was almost the same efficacy (83%) regarding eradication of E. coli biofilm. All ESBL- producing UPEC isolates were sensitive to cefoxitin (100%) followed by nitrofurantoin (98%) and imipenem (94%). Conclusion: L. acidophilus La-5 and L. helveticus B-734 may be a new therapeutic options for UTI caused by UPEC.

Whole-cell detection of live lactobacillus acidophilus on aptamer-decorated porous silicon biosensors.

This work describes the design of optical aptamer-based porous silicon (PSi) biosensors for the direct capture of Lactobacillus acidophilus. Aptamers are oligonucleotides (single-stranded DNA or RNA) that can bind their targets with high affinity and specificity, making them excellent recognition elements for biosensing applications. Herein, aptamer Hemag1P, which specifically targets the important probiotic L. acidophilus, was utilized for direct bacteria capture onto oxidized PSi Fabry-Pérot thin films. Monitoring changes in the reflectivity spectrum (using reflective interferometric Fourier transform spectroscopy) allows for bacteria detection in a label-free, simple and rapid manner. The performance of the biosensor was optimized by tuning the PSi nanostructure, its optical properties, as well as the immobilization density of the aptamer. We demonstrate the high selectivity and specificity of this simple "direct-capture" biosensing scheme and show its ability to distinguish between live and dead bacteria. The resulting biosensor presents a robust and rapid method for the specific detection of live L. acidophilus at concentrations relevant for probiotic products and as low as 10(6) cells per mL. Rapid monitoring of probiotic bacteria is crucial for quality, purity and safety control as the use of probiotics in functional foods and pharmaceuticals is becoming increasingly popular.

Lactobacillus acidophilussupplementation in human subjects and their resistance to enterotoxigenicEscherichia coliinfection

To assess the effect of Lactobacillus acidophilus (American Type Culture Collection (ATCC) 700396) on enterotoxigenic Escherichia coli (ETEC) infection, in the present study, a parallel, double-blind, placebo-controlled 4-week intervention was performed in healthy males. The subjects largely consumed their habitual diet, but had to abstain from consuming dairy foods generally high in Ca. The subjects were randomised into the L. acidophilus (dose 10⁹ colony-forming units twice daily; n 20) or the placebo (n 19) group. After an adaptation period of 2 weeks, the subjects were orally infected with a live, but attenuated, ETEC vaccine, able to induce mild, short-lived symptoms. Before and after the challenge, the subjects recorded stool consistency, bowel habits, and frequency and severity of gastrointestinal complaints. The ETEC challenge led to a significant increase in faecal output on the 2nd day and a concomitant increase in Bristol stool scale scores. Likewise, abdominal pain, bloating, flatulence, fever, headache and nausea peaked 1 d after the oral challenge. The concentrations of faecal calprotectin and IgA peaked 2 d after and that of serum IgM peaked 9 and 15 d after the oral challenge. The concentrations of serum IgA and IgG were unaffected. The ETEC challenge led to a reduction in the number of Bacteroides-Prevotella, Bifidobacterium, Clostridium cluster XIVab and total faecal bacteria. Probiotic treatment was associated with a larger increase in Bristol stool scale scores and more fever, headache and nausea after the ETEC challenge compared with the placebo treatment. These differences were, however, small and with substantial variation within the groups. Oral application of an attenuated live ETEC vaccine provides a useful model for food-borne infections. Supplementation with L. acidophilus ATCC 700396, however, was ineffective in reducing ETEC infection symptoms in healthy men.

Long-Term Use of Probiotic-Containing Yogurts Is a Safe Way to PreventHelicobacter pylori: Based on a Mongolian Gerbil's Model

Background. The suppression of Helicobacter pylori (H. pylori) decreases H. pylori-related diseases. The probiotics have an inhibitory effect on H. pylori. Aim. We investigated the effects of long-term use of yogurt on H. pylori based on Mongolian gerbils' model. Materials and Methods. Yogurt (containing a supplement of Lactobacillus acidophilus, Bifidobacterium lactis, etc.) was used. Forty-six gerbils were divided into five groups. All groups were inoculated with H. pylori for 5 to 8 weeks. The yogurt was given as follows: Group (Gr.) A: from 1st to 4th week; Gr. B from 5th to 8th week; Gr. C: from 17th week to sacrifice; Gr. D: from 5th week to sacrifice. Gerbils were sacrificed on the 52nd week. Histology was evaluated according to the Sydney system. Results. The positive rates of H. pylori were 60% (Gr. A), 75% (Gr. B), 67% (Gr. C), 44% (Gr. D), and 100% (Gr. E). Gr. D showed lower inflammatory score. Only Gr. E (60%) had intestinal metaplasia. Gr. D showed higher IL-10 and lower TNF-α expression than Gr. E. Conclusion. Long-term intake of yogurt could decrease H. pylori infection. The long-term use of yogurt would be an alternative strategy to manage H. pylori infection.

D-Fagomine lowers postprandial blood glucose and modulates bacterial adhesion

D-Fagomine is an iminosugar originally isolated from seeds of buckwheat (Fagopyrum sculentum Moench), present in the human diet and now available as a pure crystalline product. We tested D-fagomine for activities connected to a reduction in the risk of developing insulin resistance, becoming overweight and suffering from an excess of potentially pathogenic bacteria. The activities were: intestinal sucrase inhibition in vitro (rat mucosa and everted intestine sleeves), modulation of postprandial blood glucose in rats, bacterial agglutination and bacterial adhesion to pig intestinal mucosa. When ingested together with sucrose or starch, D-fagomine lowered blood glucose in a dose-dependent manner without stimulating insulin secretion. D-Fagomine reduced the area under the curve (0-120 min) by 20 % (P < 0·01) and shifted the time to maximum blood glucose concentration (Tmax) by 15 min at doses of 1-2 mg/kg body weight when administered together with 1 g sucrose/kg body weight. Moreover, D-fagomine (0·14 mm) agglutinated 60 % of Enterobacteriaceae (Escherichia coli, Salmonella enterica serovar Typhimurium) populations (P < 0·01), while it did not show this effect on Bifidobacterium spp. or Lactobacillus spp. At the same concentration, d-fagomine significantly (P < 0·001) inhibited the adhesion of Enterobacteriaceae (95-99 % cells in the supernatant) and promoted the adhesion of Lactobacillus acidophilus (56 % cells in the supernatant) to intestinal mucosa. D-Fagomine did not show any effect on bacterial cell viability. Based on all this evidence, D-fagomine may be used as a dietary ingredient or functional food component to reduce the health risks associated with an excessive intake of fast-digestible carbohydrates, or an excess of potentially pathogenic bacteria.

Influence of sunflower oil on conjugated linoleic acid production byLactobacillus acidophilus andLactobacillus casei

This study was conducted to test the conjugated linoleic acid (CLA) producing potential ofLactobacillus acidophilus NCDC-14 andLactobacillus casei NCDC-19, where sunflower oil (a rich source of linoleic acid) was used as a substrate for CLA production in skim milk at varying concentrations ranging from 0.25–1.0%.Lactobacillus casei produced higher amount of CLA i.e. 11.0 mg/g of fat at a concentration of 1.0% sunflower oil, whereasL. acidophilus produced only 2.73 mg/g of fat. However, at the lower concentration of sunflower oil (0.25%), there was no considerable difference (i.e. 6.92 and 6.73 mg/g of fat forL. casei andL. acidophilus, respectively) in the CLA producing ability of both the cultures, indicating that the increased amount of oil in the medium led to the inhibition of either the growth ofL. acidophilus or the CLA conversion. Hence,L. casei may extend a possibility to be used in the preparation of different fermented milk products for enhanced CLA content.

Preliminary characterisation of bacteriocin produced byLactobacillus acidophilus TS1 isolated from traditional dahi

Antimicrobial activity of 79 strains ofLactobacillus isolated from indigenous dahi were tested against the indicator strains of food pathogens (Escherichia coli, Streptococcus faecalis, Staphylococcus aureus, Salmonella typhi). Among these only eleven isolates produced inhibition zones of variable size against indicator microorganisms. Later on, only one strain ofLactobacillus acidophilus (TS1) was found to produce a wider zone of inhibition against all indicator microorganisms. The antimicrobial activity of this strain was inactivated by the proteolytic enzyme proteinase K and trypsin but not by α-amylase and lipase thus confirming its proteinaceous nature. It also showed a wide range of thermostability from 70–121°C for 15 min and retained their antimicrobial activity over a wide range of pH (3–10). The addition of bacteriocin to the earlier growth phase showed pronounced inhibition againstE. coli, andStreptococcus faecalis, as compared toStaphylococcus aureus, andSalmonella typhi. The molecular weight of the substance was in the range of 7.5 kDa. This result suggested that bacteriocin might be useful as a biopreservative in different food commodities.

Isolation and identification of dominant microorganisms involved in naturally fermented goat milk in Haixi region of Qinghai, China

Based upon morphological, physiological and biochemical analysis, 33 strains of lactic acid bacteria were isolated and identified from 11 samples of traditional natural fermented goat milk collected from different individual households in Haixi region of Qinghai. The counts of lactic acid bacteria were 2.5×108}3.0×109 CFU/mL, while yeasts were 2.6×106}1.6×108 CFU/mL. Strains were identified as follows: 7 strains ofLactobacillus delbrueckii susp.lactis, 4 strains ofLactobacillus delbrueckii subsp.bulgaricus, 3 strains ofLactobacillus acidophilus, 1 strain ofLactobacillus coryniformis subsp.coryniformis, 12 strains ofStreptococcus thermophilus, 1 strain ofLeuconostoc mesenteroides subsp.mesenteroides, 3 strains ofPediococcus acidilactici, and 2 strains ofAerococcus urinaeequi comb. nov.

Lactic acid fermentation of Chinese yam (Dioscorea batatas Decne) flour and its pharmacological effect on gastrointestinal function in rat model

To develop a health-aid preparation of Chinese yam (Dioscorea batatas Decne), lactic acid fermentation was attempted using a mixed starter comprising ofLactobacillus acidophilus, Streptococcus thermophilus, andBifidobacterium bifidus. The anaerobic fermentation of a 5% Chinese yam flour suspension gave a uniform suspension of pH 4.35, containing 7.76×106 CFU/mL lactic acid bacteria (LAB), and which was found to be acceptable to the panel from a sensory assessment. During the administration of the lactic acid fermented (LAF) Chinese yam to Sprague Dawley rats for 6 weeks, a smaller body weight gain, but greater excretion of feces were observed, implying the creation of a healthy gastrointestine on the administration of LAF Chinese yam, which was also confirmed by the gastrointestinal motility of the feed in rats fed on LAF Chinese yam. The constipation induced by loperamide was further suppressed in a rat group fed on a LAF Chinese yam diet, which was qualified from healthy gastrointestinal flora established by LAB. A serochemical analysis revealed a slight improvement in the blood glucose, neutral lipid and total cholesterol concentrations on administration of LAF Chinese yam, suggesting LAF Chinese yam could be served as a healthy-aid preparation, even for hyperglycemia or hyperlipidemia patients.

English

Albino rats (Rattus norvegicus) were orogastrically dosed with faecal strains ofLactobacillus acidophilus&nbsp;and simultaneously infected with&nbsp;Escherichia coli, while the control was challenged with&nbsp;E. coli&nbsp;alone. The treatment was repeated the second day and post ingestion period of 18 days follow. It was observed that rats dosed with&nbsp;L. acidophilus&nbsp;and simultaneously challenged with&nbsp;E. coli&nbsp;treatments have better performances when compared with the control for daily weight gain, total weight gain and feed conversion rate. Faecal materials of rats dosed and challenged do not show sign of diarrhoea which was observed in the&nbsp;E. coli&nbsp;only treated rats. &nbsp; Key words:&nbsp;Rats, orogastric,&nbsp;Lactobacillus acidophilus.

Molecular analysis of the microbial diversity present in the colonic wall, colonic lumen, and cecal lumen of a pig.

Random clones of 16S ribosomal DNA gene sequences were isolated after PCR amplification with eubacterial primers from total genomic DNA recovered from samples of the colonic lumen, colonic wall, and cecal lumen from a pig. Sequences were also obtained for cultures isolated anaerobically from the same colonic-wall sample. Phylogenetic analysis showed that many sequences were related to those of Lactobacillus or Streptococcus spp. or fell into clusters IX, XIVa, and XI of gram-positive bacteria. In addition, 59% of randomly cloned sequences showed less than 95% similarity to database entries or sequences from cultivated organisms. Cultivation bias is also suggested by the fact that the majority of isolates (54%) recovered from the colon wall by culturing were related to Lactobacillus and Streptococcus, whereas this group accounted for only one-third of the sequence variation for the same sample from random cloning. The remaining cultured isolates were mainly Selenomonas related. A higher proportion of Lactobacillus reuteri-related sequences than of Lactobacillus acidophilus- and Lactobacillus amylovorus-related sequences were present in the colonic-wall sample. Since the majority of bacterial ribosomal sequences recovered from the colon wall are less than 95% related to known organisms, the roles of many of the predominant wall-associated bacteria remain to be defined.

Survival Rate and Enzyme Activities ofLactobacillus acidophilusFollowing Frozen Storage

The ability of two strains ofLactobacillus acidophilus, CRL 640 and CRL 800, to survive and retain their biological activities under frozen storage was determined. Freezing and thawing, as well as frozen storage, damaged the cell membrane, rendering the microorganisms sensitive to sodium chloride and bile salts. Both lactic acid production and proteolytic activity were depressed after 21 days at −20°C, whereas β-galactosidase activity per cell unit was increased. Cell injury was partially overcome after repair in a salt-rich medium.

Effect of Intestinal Bacteria on Formation of Azoxymethane-Induced Aberrant Crypt Foci in the Rat Colon

The effect of intestinal bacteria on formation of azoxymethane (AOM)-induced aberrant crypt foci (ACF) and DNA adducts in the rat colon was investigated. Male Sprague-Dawley rats were administered cultures ofLactobacillus acidophilus, Bifidobacterium adolescentis, Bacteroides fragilis, Escherichia coliandClostridium perfringensfor five weeks and given injections of AOM at 15 mg/kg body weight at the first and second weeks. The number of ACF five weeks after the start of the experiment was decreased in the rats treated with the cultures or culture supernatants ofL. acidophilusandC. perfringens.The half-life ofO6-methylguanine (O6-meG) in theL. acidophilusgroup was shorter than that in the GAM broth group. The half-life of 7-methylguanine did not differ among the groups. These results suggest that the metabolite(s) ofL. acidophilusandC. perfringensinhibit(s) the ACF formation in rats treated with AOM and that the inhibitory effect ofL. acidophilusis due to the enhanced removal ofO6-meG from the colon mucosal DNA.

Effects of three microbial probiotics on postprandial portoarterial concentration differences of glucose, galactose and amino-nitrogen in the young pig

Postprandial kinetics of porto-arterial concentration differences of glucose (G), galactose (Gal), L-lactic acid (LA) and amino-N (AN) were studied in the piglet after the ingestion of 10(7) colony-forming units (cfu) Sporolactobacillus P44 (SP), or 10(6) cfu Bacillus cereus IP5832 (AC), or 10(6) cfu of a combination of Lactobacillus acidophilus, L. fermentum and L. brevis (AB)/g feed. Sixteen fistulated piglets (portal vein and brachiocephalic trunk; mean body weight 22 (SD 2) kg) were used. The diet was based on skimmed milk (320 g/kg), barley (300 g/kg), wheat bran (110 g/kg), maize (100 g/kg) and lactose (70 g/kg). The postprandial blood kinetics, four measurements per animal at 1-week intervals, were studied for 6 h after the ingestion of test meals of 400 g basal diet (BD) or this diet supplemented with the bacteria (SP, AC and AB respectively). Areas of porto-arterial concentration differences (APACD) of G, Gal and LA were not influenced by the bacteria supplements. APACD of AN was significantly higher after the ingestion of the SP diet than that estimated for BD.

Tomato juice as a protective agent forLactobacillus acidophilus

The extent of protection afforded by tomato juice, to two strains ofLactobacillus acidophilus during heat shock (80°C) in skimmed milk medium was studied. Presence of tomato juice or its fractions assured a higher survival of both cultures. Strain LB1H3 was more resistant than strain LACH to heat shock. Sediments gave the highest protective effect, followed by tomato juice and serum.

Survival of orally administered isolated intestinalLactobacillus acidophilus in different parts of gastrointestinal tract of mice

A strain ofLactobacillus acidophilus (Strain HF) was isolated from human faeces. A chloramphenicol resistant strain (HFCm) and a strain (HFCmSm) restant to both chloramphenicol and streptomycin were developed from the isolated strain (HF). All the three strains showed similarin vitro susceptibility against host defence factors like gastric acid, bile salts and volatile as well as non-volatile fatty acids.In vivo tests were done by feeding these strains to mice. When the resistant strains were orally administered along with the antibiotic(s) they were stable up to 72 h

A yoghurt-like product made by fermenting ultrafiltered milk containing elevated whey proteins withLactobacillus acidophilus

SUMMARYA fermented milk with typical yoghurt flavour and aroma was prepared using a human strain ofLactobacillus acidophilus. Growth of the lactobacillus was stimulated when the whey proteins of the ultrafiltered skim-milk substrate were increased by addition of ultrafiltered Cheddar cheese whey. Fermentation, which was carried out at 37 °C, was accelerated by addition of lactase. The resulting product had a smooth consistency, a pH of 4⋅2, acetaldehyde levels up to 15 p.p.m. and no off-flavours.L. acidophilusremained viable at a level of approx. 108colony forming units/ml, with no impairment of quality, for up to 14 d at 4 °C.

Death of Lactobacillus acidophilus caused by incorporated 3H-thymine during incubation without amino acids.

Of the cells of Lactobacillus acidophilus R-26 incorporated 3H-thymine (specific radioactivity 1.57 Ci/mmol or 3.15 Ci/mmol), their transfer to a medium without essential amino acids resulted in their death. This death may be interpreted in such a way that cell damage caused by disintegration of tritium cannot be effectively repaired under conditions of amino acid deprivation. The experimental eonditions make it possible to explain this death either as a result of inhibition of protein or RNA synthesis or as a result of the absence of amino acids. These possibilities were tested in experiments, in which the synthesis of proteins and RNA was inhibited by specific inhibitors in the presence of amino acids. Under these conditions no death of cells was detected, thus indicating that free amino acids play a role in the repair of radiation damage.