Lactobacillus Casei Strain Research Articles

Production of xylooligosaccharides from corncob using a crude thermostable endo-xylanase from Streptomyces thermovulgaris TISTR1948 and prebiotic properties

Production of xylooligosaccharides (XOs) from corncob using the thermostable endo-xylanase from Streptomyces thermovulgaris TISTR1948 was investigated using KOH pretreatment, followed by enzymatic hydrolysis. The optimal reaction time for production of XOs was 12 h, after which xylobiose comprised a majority of products, and a low xylose content was observed. The optimal conditions for production of XOs were studied using a central composite design. At an enzyme concentration of 129.43 U/g of substrate, 53.80°C, and pH 6.17, the yield of XOs reached 162.97 mg/g of substrate or 752.15 mg/g of hemicellulose in KOH-pretreated corncob. The prebiotic properties of XOs derived from corncob were also investigated using in vitro fermentation of those XOs with the known probiotic strains Lactobacillus casei TISTR1463, L. lactis TISTR1464, and L. plantarum TISTR1465. XOs derived from corncob were comparable to commercial XOs for an ability to enhance the growth of the specified probiotic lactobacilli.

Anticandidal activity of cell extracts from 13 probiotic Lactobacillus strains and characterisation of lactic acid and a novel fatty acid derivative from one strain

This study investigated the anti-Candida activity of methanol extracts from freeze-dried probiotic cells and the isolation of some constituents in the extracts. The MIC values of the probiotic methanol cell extracts against Candida albicans ranged between 1.25 and 5mg/ml after 48h of incubation. However, Lactococcus latics subsp. lactis strain X and Lactobacillus casei strain B extracts had an MIC of 10mg/ml after 48h of incubation. The extracts had fungistatic rather than fungicidal activity. These extracts had a much higher antifungal activity than antifungal compounds isolated from the growth medium by many other authors. This indicates that probiotics may also release antifungal compounds in their cells that could contribute to a therapeutic effect. Lactic acid (1) and 6-O-(α-D-glucopyranosyl)-1,6-di-O-pentadecanoyl-α-D-glucopyranose a novel fatty acid derivative (2) were isolated from methanol probiotic extracts and the structure of these compounds were elucidated using NMR (1 and 2D) and mass spectrometry (MS).

Generation of food-grade recombinant Lactobacillus casei delivering Myxococcus xanthus prolyl endopeptidase.

Prolyl endopeptidases (PEP) (EC 3.4.21.26), a family of serine proteases with the ability to hydrolyze the peptide bond on the carboxyl side of an internal proline residue, are able to degrade immunotoxic peptides responsible for celiac disease (CD), such as a 33-residue gluten peptide (33-mer). Oral administration of PEP has been suggested as a potential therapeutic approach for CD, although delivery of the enzyme to the small intestine requires intrinsic gastric stability or advanced formulation technologies. We have engineered two food-grade Lactobacillus casei strains to deliver PEP in an in vitro model of small intestine environment. One strain secretes PEP into the extracellular medium, whereas the other retains PEP in the intracellular environment. The strain that secretes PEP into the extracellular medium is the most effective to degrade the 33-mer and is resistant to simulated gastrointestinal stress. Our results suggest that in the future, after more studies and clinical trials, an engineered food-grade Lactobacillus strain may be useful as a vector for in situ production of PEP in the upper small intestine of CD patients.

English

Probiotics are live microbial food ingredients that have beneficial effects on consumption. The present study searched fermented food samples for potential lactobacilli that could be used for the development of novel gastrointestinal probiotics. Fifty five (55) isolates were obtained including 46 bacterial and 9 yeast isolates. On the basis of morphological and biochemical properties, 21 were identified as Lactobacillus spp. Systematic procedures were used to evaluate the probiotic properties of the Lactobacillus isolates including carbohydrate fermentation, autoaggregation, acid tolerance, bile resistance and pancreatin tolerance test. 85% of the examined Lactobacillus spp. showed the ability to form auto-aggregate, 75% can withstand bile while all the strains were able to tolerate pancreatin. Commercially available probiotic strain Lactobacillus casei was isolated and tested for functional criteria required to be a beneficial probiotics and results were compared.   Key words: Lactobacillus, probiotics, fermented food, auto-aggregation, bile tolerance.

Mucosal Vaccination with Recombinant Lactobacillus casei-Displayed CTA1-Conjugated Consensus Matrix Protein-2 (sM2) Induces Broad Protection against Divergent Influenza Subtypes in BALB/c Mice

To develop a safe and effective mucosal vaccine against pathogenic influenza viruses, we constructed recombinant Lactobacillus casei strains that express conserved matrix protein 2 with (pgsA-CTA1-sM2/L. casei) or without (pgsA-sM2/L. casei) cholera toxin subunit A1 (CTA1) on the surface. The surface localization of the fusion protein was verified by cellular fractionation analyses, flow cytometry and immunofluorescence microscopy. Oral and nasal inoculations of recombinant L. casei into mice resulted in high levels of serum immunoglobulin G (IgG) and mucosal IgA. However, the conjugation of cholera toxin subunit A1 induced more potent mucosal, humoral and cell-mediated immune responses. In a challenge test with 10 MLD50 of A/EM/Korea/W149/06(H5N1), A/Puerto Rico/8/34(H1N1), A/Aquatic bird /Korea/W81/2005(H5N2), A/Aquatic bird/Korea/W44/2005(H7N3), and A/Chicken/Korea/116/2004(H9N2) viruses, the recombinant pgsA-CTA1-sM2/L. casei provided better protection against lethal challenges than pgsA-sM2/L. casei, pgsA/L. casei and PBS in mice. These results indicate that mucosal immunization with recombinant L. casei expressing CTA1-conjugated sM2 protein on its surface is an effective means of eliciting protective immune responses against diverse influenza subtypes.

Effects of the continuous intake of a milk drink containing Lactobacillus casei strain Shirota on abdominal symptoms, fecal microbiota, and metabolites in gastrectomized subjects

Objective. This article is based on our previously reported results of irregular bowel movement and disturbances of the intestinal microbiota/environment in gastrectomized patients. A placebo-controlled, double-blind comparative study was carried out to evaluate the effects of a fermented milk beverage containing Lactobacillus casei strain Shirota (LcS) in such patients. The major evaluated factors of this article were “bowel movement” and “quality of life.” The secondary evaluated factors were “fecal microbiota” and “enteric environment.” Methods.Of the 190 gastrectomized subjects who participated in our previously reported defecation survey, 134 subjects judged as having abnormal defecation gave consent to participate in this study. These subjects continuously ingested the test beverage containing 40 billion LcS or placebo (one bottle per day, 4 weeks). Results. In the LcS-ingested group, among the 118 subjects who completed the tests, the assessments of the subjects were based on their division into groups based on their symptoms with our scoring system for constipation/diarrhea; although there was no significant ingestion effect in total, in the constipation group, LcS reduced the degree of constipation compared with that in the placebo group. In the diarrhea group, LcS ingestion improved diarrhea compared with that in the preingestion state. Fecal Staphylococcus level was decreased. Conclusions.The results suggest the possibility that the continuous consumption of LcS-fermented milk relieves irregular bowel movement in gastrectomized patients.

Lactobacillus caseistrain Shirota protects against nonalcoholic steatohepatitis development in a rodent model

Gut microbiota alterations are associated with various disorders. In this study, gut microbiota changes were investigated in a methionine-choline-deficient (MCD) diet-induced nonalcoholic steatohepatitis (NASH) rodent model, and the effects of administering Lactobacillus casei strain Shirota (LcS) on the development of NASH were also investigated. Mice were divided into three groups, given the normal chow diet (NCD), MCD diet, or the MCD diet plus daily oral administration of LcS for 6 wk. Gut microbiota analyses for the three groups revealed that lactic acid bacteria such as Bifidobacterium and Lactobacillus in feces were markedly reduced by the MCD diet. Interestingly, oral administration of LcS to MCD diet-fed mice increased not only the L. casei subgroup but also other lactic acid bacteria. Subsequently, NASH development was evaluated based on hepatic histochemical findings, serum parameters, and various mRNA and/or protein expression levels. LcS intervention markedly suppressed MCD-diet-induced NASH development, with reduced serum lipopolysaccharide concentrations, suppression of inflammation and fibrosis in the liver, and reduced colon inflammation. Therefore, reduced populations of lactic acid bacteria in the colon may be involved in the pathogenesis of MCD diet-induced NASH, suggesting normalization of gut microbiota to be effective for treating NASH.

Effect of Inoculation with Probiotics and Ageing Time on Selected Functional Properties and Oxidation of Proteins in Dry-Cured Pork Loins

The effect of inoculation with a probiotic strain Lactobacillus casei ŁOCK 0900 on changes in selected functional properties and protein oxidation of dry-cured pork loins during ageing was studied. The protein carbonyls content tended to increase significantly (p < 0.05) throughout ageing to reach a maximum level which was approximately two-fold the initial level in both samples. No statistically significant differences (p < 0.05) in carbonyl content were found between the control sample and sample inoculated with L. casei. The passage of ageing time was coupled with a statistically significant (p < 0.05) increase in the trichloroacetic acid soluble peptides concentration in examined loins. Inoculation with a probiotic strain did not have an influence on trichloroacetic acid soluble peptides concentration during the shortest ageing period. Results of measurements carried out for the control sample after 21 and 28 days of ageing were significantly lower (p < 0.05) than those obtained for the sample inoculated with L. casei ŁOCK 0900. Free α-amino acids content in both samples increased continuously with increasing ageing time (p < 0.05). Inoculation of loins with a probiotic strain Lactobacillus casei ŁOCK 0900 resulted in significantly higher peptides and free amino acids content. These differences might affect their organoleptic characteristics that need further investigations.

In vitro assessment of agave fructans (Agave salmiana) as prebiotics and immune system activators

The prebiotic effect of agave fructans (Agave salmiana) was evaluated through the growth of two lactic acid bacterial (LAB) strains (Lactobacillus casei and Bifidobacterium lactis). The immune system was activated through the stimulation of peripheral blood mononuclear cells (PBMC) of healthy subjects testing fructans, LAB or a mixture of these compounds at different concentrations. Immune responses, such as early cell activation (CD69), cell cycle progression, nitric oxide (NO) production and the expression of transcription factors for lymphocyte differentiation, were analyzed. Compared with other fructans, the extracted agave fructans showed the highest prebiotic activity and increased levels of CD69 expression, proliferative activity and NO production when administered with the probiotic L. casei. The Th1 lymphocyte differentiation produced through LAB stimulation was greatly diminished after the incorporation of agave fructans. In conclusion, these types of fructans (A. salmiana) are involved in the activation and selective differentiation of cells of the immune system through interactions with probiotics. Thus, agave fructans represent a novel immunomodulator that might benefit the functional food industry.

Injection of Lactobacillus casei strain Shirota affects autonomic nerve activities in a tissue-specific manner, and regulates glucose and lipid metabolism in rats.

Previously, it was observed that long-term ingestion of a probiotic strain Lactobacillus casei Shirota (LcS) ameliorates insulin resistance and glucose intolerance in rats fed a high-fat diet. In the present study, we examined its possible role in the autonomic nervous system during LcS-induced modulations in glucose and lipid metabolism or cardiovascular functions. The present study examined the effects of intragastric (IG) LcS injection on autonomic nerve tones in anesthetized rats by electrophysiological method. We found that an IG injection of LcS suppressed neural activity of sympathetic nerves supplying the white adipose tissue of urethane-anesthetized rats in a dose-dependent manner, whereas sympathetic nerve outflow to brown adipose tissue was not affected by the IG LcS injection. Furthermore, the IG LcS injection reduced efferent sympathetic nerve outflow to the adrenal gland and liver, but did not alter gastric vagal nerve activity, renal sympathetic nerve activity, as well as mean arterial pressure. To test the involvement of afferent vagal nerves and the abdominal organs, we examined the adrenal sympathetic response to an LcS injection in rats with ablated afferent vagal nerves, and found that the adrenal sympathetic nerve response to LcS was inhibited in vagotomized rats. In addition, we found that oral ingestion of LcS attenuated the hyperglycemic response to glucose loading and blood glycerol levels in conscious rats. Our data suggest that LcS might affect tissue-specific autonomic nerves through the afferent vagal nerve pathway to modulate glucose and lipid metabolism.

The effect of a commercial probiotic drink containing Lactobacillus casei strain Shirota on oral health in healthy dentate people.

BackgroundIn the past decade, the use of probiotic-containing products has been explored as a potential alternative in oral health therapy. A widely available probiotic drink, Yakult, was evaluated for oral health applications in this longitudinal study. Selected oral health parameters, such as levels and composition of salivary and tongue plaque microbiota and of malodorous gases, in dentate healthy individuals were investigated for changes. The persistence of the probiotic strain in the oral cavity was monitored throughout the study period.MethodsA three-phase study (7 weeks) was designed to investigate simultaneously the effect of 4-week consumption of the probiotic-containing milk drink Yakult on the microbiota of saliva and dorsum tongue coating in healthy dentate people (n = 22) and levels of volatile sulphur compounds (VSCs) in morning breath. Study phases comprised one baseline visit, at which ‘control’ levels of oral parameters were obtained prior to the probiotic product consumption; a 4-week period of daily consumption of one 65 ml bottle of Yakult, each bottle containing a minimum of 6.5×109 viable cells of Lactobacillus casei strain Shirota (LcS); and a 2-week washout period. The microbial viability and composition of saliva and tongue dorsum coating were assessed using a range of solid media. The presence of LcS in the oral cavity was investigated using a novel selective medium, ‘LcS Select’. Portable sulphur monitors Halimeter® and OralChromaTM were used to measure levels of VSCs in morning breath.ResultsUtilization of the LcS Select medium revealed a significant (p < 0.05) but temporary and consumption-dependent presence of LcS in saliva and tongue plaque samples from healthy dentate individuals (n = 19) during the probiotic intervention phase. LcS was undetectable with culture after 2 weeks of ceasing its consumption. Morning breath scores measured with Halimeter and OralChroma were not significantly affected throughout the trial, except in a small number of individual cases where Halimeter scores were significantly reduced during the probiotic intervention period. Natural fluctuations in resident acidogenic populations, and numbers of Candida and anaerobic species, including malodourous Gram-negative anaerobes, were unaffected.ConclusionWhile no broad ecological changes in the mouth were induced by consumption of Yakult in healthy dentate individuals, findings of this study confirm the temporary and intake-dependent presence of LcS. Future studies could focus on subjects at greater risk of oral infection, where ill-defined microbiota (e.g. an increased presence of periopathogens) or clinically diagnosed halitosis might be significantly affected by consumption of this probiotic.

Impact of Lactose Starvation on the Physiology of Lactobacillus casei GCRL163 in the Presence or Absence of Tween 80

The global proteomic response of the nonstarter lactic acid bacteria Lactobacillus casei strain GCRL163 under carbohydrate depletion was investigated to understand aspects of its survival following cessation of fermentation. The proteome of L. casei GCRL163 was analyzed quantitatively after growth in modified MRS (with and without Tween 80) with different levels of lactose (0% lactose, starvation; 0.2% lactose, growth limiting; 1% lactose, non-growth-limited control) using gel-free proteomics. Results revealed that carbohydrate starvation lead to suppression of lactose and galactose catabolic pathways as well as pathways for nucleotide and protein synthesis. Enzymes of the glycolysis/gluconeogenesis pathway, amino acid synthesis, and pyruvate and citrate metabolism become more abundant as well as other carbohydrate catabolic pathways, suggesting increased optimization of intermediary metabolism and scavenging. Tween 80 did not affect growth yield; however, proteins related to fatty acid biosynthesis were repressed in the presence of Tween 80. The data suggest that L. casei adeptly switches to a scavenging mode, using both citrate and Tween 80, and efficiently adjusts energetic requirements when carbohydrate starved and thus can sustain survival for weeks to months. Explaining the adaptation of L. casei during lactose starvation will assist efforts to maintain viability of L. casei and extend its utility as a beneficial dietary adjunct and fermentation processing aid.

Effect of three Lactobacillus strains on lipid metabolism in rats fed a high-cholesterol diet

Probiotics are known as functional foods and have been recommended as dietary adjuncts to hypercholesterolemic subjects. The objective of the present study was to evaluate the effect of three Lactobacillus strains on lipid metabolism in rats fed a high-cholesterol diet. The results showed that Lactobacillus acidophilus CH5, Lactobacillus casei strain Shirota and L. acidophilus NCFM were able to deconjugate bile acids in vitrobut the same species did not significantly alter the serum levels of cholesterol, triglycerides and bile acids of rats fed a high cholesterol diet, showing that the three probiotic species administered, although they were able to deconjugate bile acids, did not influence the lipid metabolism of the experimental animals. Key words: Probiotic, functional food, health claim, bile salt hydrolase, lactic acid bacteria.

New fermented functional product based on soy milk and sea buckthorn syrup

The possibility of producing beverages based on soy milk–sea buckthorn syrup, fermented by Lactobacillus casei ssp. paracasei strain was examined. Our results show that the viable cell counts and acidity increased, while water holding capacity of the fermented samples decreased with the increase in sea buckthorn syrup concentration from 5 to 20%. Lactobacillus casei strain had a good survival (1.3 × 1011 CFU mL−1 for the beverages with 20.0% sea buckthorn syrup fermented at 37°C) in ready to serve beverage when stored at 4°C and may survive the passage through the human gastro-intestinal tract. In case of the sample with 5% sea buckthorn syrup, the total number of L. casei cells surviving after 120 min of gastric and intestinal conditions was 23 and 24% for the fermentation temperatures of 30 and 37°C, respectively. Therefore, the soy milk-based beverages tested in the present study can be successfully classified as probiotic products.

Decreased duration of acute upper respiratory tract infections with daily intake of fermented milk: A multicenter, double-blinded, randomized comparative study in users of day care facilities for the elderly population

There is insufficient evidence of preventive effect of probiotics on upper respiratory tract infections (URTIs) in an elderly population. We conducted a multicenter, double-blinded, randomized, placebo-controlled parallel group study. Elderly persons had participated who used day care at 4 facilities in Tokyo. We used fermented milks containing Lactobacillus casei strain Shirota (LcS) and placebo drinks as test drinks. A total of 154 subjects was analyzed. The number of persons diagnosed with an acute URTIs was almost identical in both groups (LcS: 31, placebo: 32), whereas the number of acute URTIs events (LcS: 68, placebo: 51) and the symptom score (LcS: 425, placebo: 396) were both higher in the LcS group. Permutation tests performed using the total number of acute URTIs infection events/total days of observation and the total symptom score/total days of observation found no statistically significant difference respectively (P values of .89 and .64, respectively). Comparing the mean duration of infection per infection event found a shorter mean duration in the LcS group (LcS: 3.71 days, placebo: 5.40 days), and the difference was statistically significant. The results suggest that fermented milk containing LcS probably reduces the duration of acute URTIs.

Compound(s) secreted by Lactobacillus casei strain Shirota YIT9029 irreversibly and reversibly impair the swimming motility of Helicobacter pylori and Salmonella enterica serovar Typhimurium, respectively

We conducted experiments in order to examine whether the probiotic Lactobacillus casei strain Shirota YIT9029 (LcS) in vitro and in vivo antagonism of Helicobacter pylori and Salmonella, involves inhibition of the swimming motility of these pathogens. We report the irreversible inhibition of the swimming motility of H. pylori strain 1101 and reversible inhibition of Salmonella enterica serovar Typhimurium (S. Typhimurium) strain SL1344 by compound(s) secreted by LcS. In H. pylori 1101, irreversible inhibition results in the helical cells being progressively replaced by cells with 'c'-shaped and coccoid morphologies, accompanied by a loss of FlaA and FlaB flagellin expression. In S. Typhimurium SL1344, transient inhibition develops after membrane depolarization and without modification of expression of FliC flagellin. The inhibitory activity of strain LcS against both S. Typhimurium and H. pylori swimming motilities is linked with a small sized, heat-sensitive, and partially trypsin-sensitive, secreted compound(s), and needed the cooperation of the secreted membrane permeabilizing lactic acid metabolite. The inhibition of S. Typhimurium SL1344 swimming motility leads to delayed cell entry into human enterocyte-like Caco-2/TC7 cells and a strong decrease of cell entry into human mucus-secreting HT29-MTX cells.

Comparative genome analysis of Lactobacillus casei strains isolated from Actimel and Yakult products reveals marked similarities and points to a common origin

SummaryThe members of the Lactobacillus genus are widely used in the food and feed industry and show a remarkable ecological adaptability. Several Lactobacillus strains have been marketed as probiotics as they possess health-promoting properties for the host. In the present study, we used two complementary next-generation sequencing technologies to deduce the genome sequences of two Lactobacillus casei strains LcA and LcY, which were isolated from the products Actimel and Yakult, commercialized as probiotics. The LcA and LcY draft genomes have, respectively, an estimated size of 3067 and 3082 Mb and a G+C content of 46.3%. Both strains are close to identical to each other and differ by no more than minor chromosomal re-arrangements, substitutions, insertions and deletions, as evident from the verified presence of one insertion-deletion (InDel) and only 29 single-nucleotide polymorphisms (SNPs). In terms of coding capacity, LcA and LcY are predicted to encode a comparable exoproteome, indicating that LcA and LcY are likely to establish similar interactions with human intestinal cells. Moreover, both L. casei LcA and LcY harboured a 59.6 kb plasmid that shared high similarities with plasmids found in other L. casei strains, such as W56 and BD-II. Further analysis revealed that the L. casei plasmids constitute a good evolution marker within the L. casei species. The plasmids of the LcA and LcY strains are almost identical, as testified by the presence of only three verified SNPs, and share a 3.5 kb region encoding a remnant of a lactose PTS system that is absent from the plasmids of W56 and BD-II but conserved in another smaller L. casei plasmid (pLC2W). Our observations imply that the results obtained in animal and human experiments performed with the Actimel and Yakult strains can be compared with each other as these strains share a very recent common ancestor.Funding Information The present work was supported by the Center of Excellence in Microbial Food Safety Research (Academy of Finland, Grant 141140), Grant ERC 250172 – Microbes Inside from the European Research Council and Grants 137389 and 141130 from the Academy of Finland. F.P.D. was funded by a postdoctoral research fellowship (Academy of Finland, Grant 252123).

Effects of a probiotic fermented milk on functional constipation: A randomized, double‐blind, placebo‐controlled study

Evidence suggests that probiotics reduce certain constipation-related symptoms. Lactobacillus casei strain Shirota has never been tested as treatment for functional constipation in otherwise-healthy subjects. To evaluate the efficacy of this probiotic among adults with functional constipation was aimed. Subjects with functional constipation (Rome II-defined) were randomized to intake L. casei strain Shirota fermented milk or placebo once daily for 4 weeks under double-blind condition. Primary outcomes were constipation severity and stool frequency; secondary outcomes were stool consistency and quantity. In intent-to-treat population, compared with baseline, constipation severity and stool frequency improved in both probiotic (n = 47) and control groups (n = 43), but improvements were comparable in both groups at week 4 (α = 5% level). In probiotic group, stool consistency and quantity at week 4 improved significantly versus baseline but not versus control. Considering that the study agent is non-pharmaceutical and the purpose of supplementation is for long-term effect, re-evaluation at α = 10% was conducted, which showed significant improvement in constipation severity at week 4 (P = 0.058). Magnitude of the probiotic effect on stool consistency was small but grew over time, d = 0.19, 95% confidence interval 0.00-0.35 (Week 4), d = 0.29, 95% confidence interval 0.11-0.52 (postintervention). Post-hoc exploratory analysis suggests incomplete evacuation may decrease with probiotic intake. Four-week administration of L. casei strain Shirota did not alleviate constipation severity or stool frequency, consistency, and quantity when compared with control. With re-evaluation at α = 10% level, improvement in constipation severity was significant at week 4. To obtain conclusive results, further studies with longer intervention are warranted.

PTH-004 Prevention of Relapse following Clostridium Difficile Infection using Probiotics: A Retrospective Case-Control study

IntroductionClostridium difficile infection is an important hospital acquired infection causing significant healthcare burden. Once patients have had C diff diarrhoea, recurrence rates are high with 44.8% of patients having a...

Monitoring survival of Lactobacillus casei ATCC 393 in probiotic yogurts using an efficient molecular tool

The aim of the present study was to monitor the survival of the probiotic strain Lactobacillus casei ATCC 393 during refrigerated storage of natural regular yogurts compared with Lactobacillus delbrueckii ssp. bulgaricus. Both free and immobilized cells on supports of high industrial interest, such as fruits and oat pieces, were tested. Microbiological and strain-specific multiplex PCR analysis showed that both free and immobilized Lb. casei ATCC 393 were detected in the novel products at levels required to confer a probiotic effect (at least 6logcfu/g) for longer periods than required by the dairy industry (≥30d) during storage at 4°C. In contrast, the viable bacterial density of Lb. delbrueckii ssp. bulgaricus decreased to levels <6logcfu/g after 14d of cold storage. Of note, the final pH of all products was 4.2 to 4.3. Acid resistance or cold tolerance of Lb. casei ATCC 393 apparently allows for increased survival compared with Lb. delbrueckii ssp. bulgaricus in these yogurt formulations.