Lactobacillus helveticus Prevents Periodontitis Induced by Aggregatibacter actinomycetemcomitans in Rats by Regulating ß-Defensins.

Objective: To study the preventive effect of Lactobacillus helveticus (L. helveticus) on periodontitis induced by Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in rats. Methods: Eighteen 8-week-old female rats were randomly divided into three groups: Sham group, Trehalose group, and L. helveticus SBT2171 (LH2171) group. We measured the distance of the cementoenamel junction-alveolar bone crest (CEJ-ABC) to evaluate alveolar bone resorption. Hematoxylin-eosin staining was used to observe the histopathological changes of rat hemimaxillary tissues. We detected the expression of ß-defensins, tumor necrosis factor-α (TNF-α), interleukin- (IL-) 1ß, and IL-6 and the number of A. actinomycetemcomitans in rat gingival tissues by quantitative reverse transcriptase polymerase chain reaction. The levels of IL-1ß, IL-6, and TNF-α in rat gingival tissues were also measured by enzyme-linked immunosorbent assay. Results: Compared with the Trehalose group, the distance of CEJ-ABC was prominently reduced and alveolar bone resorption was notably improved in the LH2171 group. And the infiltration of inflammatory cells in the hemimaxillary tissue decreased obviously, periodontal fibers were arranged neatly, connective tissue small blood vessels proliferated, and the number of A. actinomycetemcomitans reduced significantly in the LH2171 group. In addition, the mRNA expression and release of inflammatory factors in the gingival tissues in the LH2171 group were notably lower than those in the Trehalose group. On the 21st and 36th day, the expression of ß-defensins in the gingival tissue of the LH2171 group increased significantly. Conclusion: L. helveticus improves alveolar bone resorption and increases the expression of ß-defensins thereby inhibiting the number of A. actinomycetemcomitans and thus prevents periodontitis.

Niche-specific adaptation of Lactobacillus helveticus strains isolated from malt whisky and dairy fermentations.

Lactobacillus helveticus is a well characterized lactobacillus for dairy fermentations that is also found in malt whisky fermentations. The two environments contain considerable differences related to microbial growth, including the presence of different growth inhibitors and nutrients. The present study characterized L. helveticus strains originating from dairy fermentations (called milk strains hereafter) and malt whisky fermentations (called whisky strains hereafter) by in vitro phenotypic tests and comparative genomics. The whisky strains can tolerate ethanol more than the milk strains, whereas the milk strains can tolerate lysozyme and lactoferrin more than the whisky strains. Several plant-origin carbohydrates, including cellobiose, maltose, sucrose, fructooligosaccharide and salicin, were generally metabolized only by the whisky strains, whereas milk-derived carbohydrates, i.e. lactose and galactose, were metabolized only by the milk strains. Milk fermentation properties also distinguished the two groups. The general genomic characteristics, including genomic size, number of coding sequences and average nucleotide identity values, differentiated the two groups. The observed differences in carbohydrate metabolic properties between the two groups correlated with the presence of intact specific enzymes in glycoside hydrolase (GH) families GH1, GH4, GH13, GH32 and GH65. Several GHs in the milk strains were inactive due to the presence of stop codon(s) in genes encoding the GHs, and the inactivation patterns of the genes encoding specific enzymes assigned to GH1 in the milk strains suggested a possible diversification manner of L. helveticus strains. The present study has demonstrated how L. helveticus strains have adapted to their habitats.

The molecular mechanisms of probiotic strains in improving ageing bone and muscle of d-galactose-induced ageing rats.

AIM: The aim of this study was to evaluate the molecular mechanisms of Lactobacillus strains in improving ageing of the musculoskeletal system. METHODS AND RESULTS: The anti-ageing mechanism of three probiotics strains Lactobacillus fermentum DR9, Lactobacillus paracasei OFS 0291 and L. helveticus OFS 1515 were evaluated on gastrocnemius muscle and tibia of d-galactose-induced ageing rats. Upon senescence induction, aged rats demonstrated reduced antioxidative genes CAT and SOD expression in both bone and muscle compared to the young rats (P < 0·05). Strain L. fermentum DR9 demonstrated improved expression of SOD in bone and muscle compared to the aged rats (P < 0·05). In the evaluation of myogenesis-related genes, L. paracasei OFS 0291 and L. fermentum DR9 increased the mRNA expression of IGF-1; L. helveticus OFS 1515 and L. fermentum DR9 reduced the expression of MyoD, in contrast to the aged controls (P < 0·05). Protective effects of L. fermentum DR9 on ageing muscle were believed to be contributed by increased AMPK-α2 expression. Among the osteoclastogenesis genes studied, TNF-α expression was highly elevated in tibia of aged rats, while all three probiotics strains ameliorated the expression. Lactobacillus fermentum DR9 also reduced the expression of IL-6 and TRAP in tibia when compared to the aged rats (P < 0·05). All probiotics treatment resulted in declined proinflammatory cytokines IL-1ß in muscle and bone. CONCLUSIONS: Lactobacillus fermentum DR9 appeared to be the strongest strain in modulation of musculoskeletal health during ageing. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrated the protective effects of the bacteria on muscle and bone through antioxidative and anti-inflammatory actions. Therefore, L. fermentum DR9 may serve as a promising targeted anti-ageing therapy.

Biodiversity of Lactobacillus helveticus isolates from dairy and cereal fermentations reveals habitat-adapted biotypes.

For the present study, we collected 22 Lactobacillus helveticus strains from different dairy (n = 10) and cereal (n  = 12) fermentations to investigate their biodiversity and to uncover habitat-specific traits. Biodiversity was assessed by comparison of genetic fingerprints, low-molecular-weight subproteomes, metabolic and enzymatic activities, growth characteristics and acidification kinetics in food matrices. A clear distinction between the dairy and cereal strains was observed in almost all examined features suggesting that the different habitats are domiciled by different L. helveticus biotypes that are adapted to the specific environmental conditions. Analysis of the low-molecular-weight subproteome divided the cereal isolates into two clusters, while the dairy isolates formed a separate homogeneous cluster. Differences regarding carbohydrate utilization were observed for lactose, galactose, sucrose and cellobiose as well as for plant-derived glucosides. Enzymatic differences were observed mainly for ß-galactosidase and ß-glucosidase activities. Further, growth temperature was optimal in the range from 33 to 37°C for the cereal strains, whereas the dairy strains showed optimal growth at 40°C. Taken together, adaptation of the various biotypes results in a growth benefit in the particular environment. Acidification and growth tests using either sterile skim milk or a wheat flour extract confirmed these results. Differentiation of these biotypes and their physiological characteristics enables knowledge-based starter culture development for cereal versus dairy products within one species.

The protective effects of enriched citrulline fermented milk with Lactobacillus helveticus on the intestinal epithelium integrity against Escherichia coli infection.

This study examined the protective effects of citrulline enriched-fermented milk with live Lactobacillus helveticus ASCC 511 (LH511) on intestinal epithelial barrier function and inflammatory response in IPEC-J2 cells caused by pathogenic Escherichia coli. Five percent (v/v) of fermented milk with live LH511 and 4 mM citrulline (5%LHFM_Cit-4mM) significantly stimulated the population of IPEC-J2 cells by 36% as determined by MTT assay. Adhesion level of LH511 was significantly increased by 9.2% when incubated with 5%LHFM_Cit-4mM and 5%LHFM_Cit-4mM reduced the adhesion of enterohemorrhagic (EHEC) and entero-invasive (EIEC) E. coli in IPEC-J2 cells by 35.79% and 42.74%, respectively. Treatment with 5%LHFM_Cit-4mM ameliorated lipopolysaccharide (LPS) from E. coli O55:B5 induced activated inflammatory cytokines expression (TNF-α, IL-6 and IL-8) and concentration (IL-6 and IL-8) and early apoptosis. It restored the transepithelial electrical resistance (TEER) and regulated the expression and distribution of tight junction (TJ) proteins (zonula occluden-1 (ZO-1), occludin and claudin-1), toll-like receptors (TLRs) (TLR2 and TLR4) and negative regulators of TLRs signalling pathway (A20 and IRAK-M). In conclusion, our findings suggested that 5%LHFM_Cit-4mM might have the positive effects on improving and maintaining the intestinal epithelial cell integrity and inflammatory response under both normal and pathogenic LPS-stimulated conditions.

Probiotic Properties of Lactobacillus helveticus and Lactobacillus plantarum Isolated from Traditional Pakistani Yoghurt.

Probiotic bacteria are of utmost importance owing to their extensive utilisation in dairy products and in the prevention of various intestinal diseases. The objective of this study was to assess the probiotic properties of bacteriocin-producing isolates of Lactobacillus helveticus and Lactobacillus plantarum isolated from traditional Pakistani yoghurt. In this study, ten bacteriocin-producing isolates were selected to screen for the probiotic property. The isolates showed resistance to acidic pH (6-6.5), bile salt (0.01-1%), and 1-7% NaCl salt and showed good growth at acidic pH and antibacterial activity against ten different foodborne pathogens. Interestingly, these isolates were proved to be effective against Actinobacter baumannii but least effective against Klebsiella pneumoniae and Pseudomonas aeruginosa. A few isolates were found to be resistant to some antibiotics like vancomycim, gentamycin, erythromycin, streptomycin, and clindamycin. Our results provide strong evidence in favour of traditional Pakistani yoghurts as a potential source of bacteriocin-producing bacteria with an added benefit of the probiotic property. Specifically, LBh5 was considered a good probiotic isolate as compared to other isolates used in the study. Further extensive research should be done on isolation and characterisation of probiotic isolates from local fermented foods, and then, these isolates should be used in the development of probiotic enriched food supplements in Pakistan.

Lactobacillus helveticus R0052 alleviates liver injury by modulating gut microbiome and metabolome in D-galactosamine-treated rats.

The liver is an important digestive gland, and acute liver failure results in high mortality. Probiotics are considered potential adjuvant therapies for liver disease. This study aimed to investigate the beneficial effects of Lactobacillus helveticus R0052 on acute liver injury and the underlying mechanisms. Sprague-Dawley rats were gavaged with L. helveticus R0052 suspensions (3 × 109 CFU) for 1 week. Subsequently, acute liver injury was induced by intraperitoneal D-galactosamine injection on the eighth day. After 24 h, samples (blood, liver, ileum, faeces) were collected and assessed for histological injury, inflammation, intestinal barrier, gut microbiome and metabolome. L. helveticus R0052 alleviated aminotransferase, bilirubin and total bile acid elevation and histological hepatic injuries. Additionally, L. helveticus R0052 exhibited anti-inflammatory properties by downregulating Toll-like receptors, tumour necrosis factor-α and nuclear factor-κb transcription in liver samples and decreasing proinflammatory cytokine plasma concentrations. Additionally, L. helveticus R0052 ameliorated intestinal abnormalities and regulated Toll-like receptors, claudin2 and mucin3 gene transcription in the intestine. These effects were associated with gut microbiome and metabolome modulation by L. helveticus R0052. Probiotic pretreatment enriched Lactobacillus and Bacteroides and depleted Flavonifractor and Acetatifactor in the gut microbiome. Meanwhile, L. helveticus R0052 improved carbohydrate and fatty acid metabolism and reduced lithocholic acid levels. These results indicate that L. helveticus R0052 is promising for alleviating acute liver injury and provide new insights regarding the correlations among the microbiome, the metabolome, the intestinal barrier and liver disease.

Lactobacillus helveticus SBT2171 upregulates the expression of ß-defensin and ameliorates periodontal disease caused by Porphyromonas gingivalis.

Antimicrobial peptides play important roles in the innate immune system of various organisms, and they may also be considered to prevent the organisms from infections. In particular, ß-defensins, mainly produced in epithelial cells, are recognized as one of the major antimicrobial peptides in mammals, including humans. In this study, we showed that Lactobacillus helveticus SBT2171 (LH2171), one of the several species of lactic acid bacteria, upregulates the production of ß-defensins in oral epithelial cells in vitro. Moreover, LH2171 reduced the increase of proinflammatory cytokine expression, induced by Porphyromonas gingivalis stimulation, in gingival epithelial cells. These data suggested that LH2171 suppresses P. gingivalis-induced inflammation by upregulating the expression of ß-defensins in gingival epithelial cells. We subsequently investigated the effects of LH2171 in vivo and revealed that ß-defensin expression was increased in the oral cavities of LH2171-fed mice. Furthermore, LH2171 decreased alveolar bone loss, gingival inflammation, and amounts of P. gingivalis-specific 16S ribosomal RNA in the gingiva of P. gingivalis-inoculated mice. Taken together, our results showed that LH2171 upregulates the expression of ß-defensins in oral cavity, thereby decreasing the number of P. gingivalis consequently ameliorating the experimental periodontal disease.

Heat-killed Lactobacillus helveticus strain MCC1848 confers resilience to anxiety or depression-like symptoms caused by subchronic social defeat stress in mice.

The gut microbiota is involved in the pathogenesis of stress-related disorders. Probiotics can benefit the central nervous system via the microbiota-gut-brain axis, which raises the possibility that probiotics are effective in managing depression. In the present study, we examined the effects of heat-killed Lactobacillus helveticus strain MCC1848 in subchronic and mild social defeat stress (sCSDS) model mice (a widely used animal model of depression). MCC1848 supplementation significantly enhanced the interaction time in the social interaction test and sucrose preference ratio in the sucrose preference test, suggesting that MCC1848 improved anxiety- or depressive-like behaviors in sCSDS mice. The gene expression profile analysis of the nucleus accumbens, which plays an important role in stress resilience, indicated that MCC1848 ameliorated sCSDS-induced gene expression alterations in signal transduction or nervous system development. These findings suggest that MCC1848 supplementation is useful as a preventive strategy for chronic-stress-induced depression.

Effect of Dietary Probiotic Lactobacillus helveticus on Growth Performance, Antioxidant Levels, and Absorption of Essential Trace Elements in Goldfish (Carassius auratus).

In this study, we have investigated the effect of probiotic Lactobacillus helveticus CD6 supplemented into simple laboratory fish feed (LFF) and complex, multi-ingredient market fish feed (MFF) on growth performance, antioxidant levels, and essential trace element absorption in goldfish (Carassius auratus). Twenty-four healthy goldfish (average weight 3-4 g) were acclimatized and divided into four experimental diets supplemented with 3 × 107 CFU/g of probiotic (LFF + Pro, MFF + Pro) and without probiotic (LFF, MFF) for 14 weeks. Fish fed with probiotic were healthy, active, and intense orange-gold as compared to control (without probiotic). At 14 weeks, fish fed with MFF + Pro/LFF + Pro showed 91/47% weight gain as compared to 34/- 12% weight observed with MFF/LFF. The average weight gain differences recorded between probiotic and control diets were not significant. No mortality to report when fish fed with probiotic. In contrast, fish fed without probiotic showed mortalities (LFF, two fish; MFF, one fish) during the trial. DPPH activity revealed high levels of antioxidants into the intestine of probiotic-fed fish. Trace element analysis showed that probiotic colonization enhanced diet-dependent absorption of Fe and Zn. The in vitro antimicrobial activity was exhibited by probiotic L. helveticus CD6 against infected fish isolate Aeromonas spp. JA showed an ability to protect fish from infections. Moreover, complex, multi-ingredient feed had a highest impact on viability of probiotic during storage. In conclusion, L. helveticus CD6 did not significantly enhance growth performance; however, it improved health and reduced mortalities in goldfish (C. auratus) regardless of the composition of the diet.

Lactobacillus helveticus KLDS1.8701 alleviates d-galactose-induced aging by regulating Nrf-2 and gut microbiota in mice.

Aging is commonly associated with chronic oxidative stress and mild inflammation that can cause a variety of degenerative diseases. Lactic acid bacteria (LAB) provide several health benefits to the host including antioxidant activity and immune system regulation. However, there is a lack of information regarding the antioxidant mechanisms of probiotics in vivo. Therefore, the aim of this study was to elucidate the possible mechanisms for the preventive effect of LAB on aging. First, 25 LAB strains were screened for finding potential probiotics with high antioxidant capacity using in vitro methods. Second, d-galactose was administered by subcutaneous injection once daily for 8 weeks to establish an aging mouse model to investigate the protective effects and underlying mechanisms of the potential probiotic strain Lactobacillus helveticus KLDS1.8701, identified from the screening. The results in vitro showed that L. helveticus KLDS1.8701 had a better property with remarkable free radical scavenging activity. In vivo, L. helveticus KLDS1.8701 supplementation significantly ameliorated aging-related changes such as decreased organic index, liver injury and increased endotoxin. L. helveticus KLDS1.8701 supplementation reduced hepatic oxidative stress by modulating the Nrf-2 pathway. Notably, L. helveticus KLDS1.8701 supplementation restored the gut microbiota composition to that of the control group, resulting in increased butyrate production and decreased endotoxin production. These findings indicated that L. helveticus KLDS1.8701 supplementation manipulated gut microbiota and its metabolites could attenuate hepatic oxidative stress via the gut-liver axis.

A Mixture of Five Bacterial Strains Attenuates Skin Inflammation in Mice.

BACKGROUND: There is a growing interest in the effects of probiotics for the prevention and treatment of skin diseases due to their immunomodulatory and antiinflammatory properties. OBJECTIVE: To assess a mixture of five bacterial strains in the prevention of chronic skin inflammation in mice. METHODS: Hairless SKH-1 mice received daily oral treatment with the probiotic mixture at the dose of 1x109 Colony-Forming Unit (CFU)/day (or vehicle) for three weeks. Chronic skin inflammation was induced by repeated applications of 12-O-tetradecanoylphorbol-13- acetate (TPA; control mice received acetone). Macroscopic and microscopic evaluations of skin lesions were performed and serum levels of interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF)-α, IL-17, IL-22, IL-10 and IL-4 measured at the end of the study. RESULTS: Treatment with the probiotic mixture significantly limited the induced chronic skin inflammation at both the macroscopic and microscopic levels. This limitation was consistent with downregulated levels of pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α, IL- 17 and IL-22) and up-regulated levels of the anti-inflammatory cytokines, IL-10 and IL-4. CONCLUSION: The results suggest that the probiotic mixture tested could help in preserving skin integrity and homeostasis and that its use could be beneficial in dermatological conditions such as atopic dermatitis and psoriasis.

Characterization of volatile compounds produced by Lactobacillus helveticus strains in a hard cheese model.

Starter cultures of Lactobacillus helveticus used in hard cooked cheeses play an important role in flavor development. In this work, we studied the capacity of three strains of L. helveticus, two autochthonous (Lh138 and Lh209) and one commercial (LhB02), to grow and to produce volatile compounds in a hard cheese extract. Bacterial counts, pH, profiles of organic acids, carbohydrates, and volatile compounds were analyzed during incubation of extracts for 14 days at 37 ℃. Lactobacilli populations were maintained at 106 CFU ml-1 for Lh138, while decreases of approx. 2 log orders were found for LhB02 and Lh209. Both Lh209 and LhB02 slightly increased the acetic acid content whereas mild increase in lactic acid was produced by Lh138. The patterns of volatiles were dependent on the strain which reflect their distinct enzymatic machineries: LhB02 and Lh209 produced a greater diversity of compounds, while Lh138 was the least producer strain. Extracts inoculated with LhB02 and Lh 209 were characterized by ketones, esters, alcohols, aldehydes, and acids, whereas in the extracts with Lh138 the main compounds belonged to aromatic, aldehydes, and ketones groups. Therefore, Lh209 and LhB02 could represent the best cheese starters to improve and intensify the flavor, and even a starter composed by combinations of LhB02 or Lh209 with Lh138 could also be a strategy to diversify cheese flavor.

Safety and tolerance of three probiotic strains in healthy infants: a multi-centre randomized, double-blind, placebo-controlled trial.

Some strains of species belonging to the genera Bifidobacterium and Lactobacillus are used in order to maintain health. Although these organisms have a long record of safe use, it is important to assess their safety and tolerance in potentially vulnerable populations, such as infants. The objective of this study was to evaluate the safety and tolerance of three probiotic strains (Bifidobacterium longum subsp. infantis R0033, Bifidobacterium bifidum R0071 and Lactobacillus helveticus R0052) in healthy infants aged 3 to 12 months. A multi-centre randomized, double-blind, placebo-controlled intervention study with 221 healthy full-term infants was conducted. Infants received either a placebo or one of the 3 probiotic strains (3×109 cfu) daily during an 8 week intervention period. Growth (weight, height and head circumference), adverse events (AEs)/serious adverse events (SAEs), concentrations of D-lactic acid in urine samples, characteristics of the stools and use of medication were collected for safety evaluation. All 4 groups were homogeneous with respect to age, gender, feeding type, ethnicity, height, weight and head circumference at the start of the study. The results showed that changes in growth (weight, height and head circumference) were equivalent in all 4 groups. No SAEs were reported. Total number of AEs recorded was equivalent in all groups. Thus, the use of B. infantis R0033, L. helveticus R0052 and B. bifidum R0071 in infancy is safe, and well tolerated.

In vitro and in vivo antagonistic activity of new probiotic culture against Clostridium difficile and Clostridium perfringens.

BACKGROUND: Genus Clostridium accompanies more than 200 known species and at least 30 among them are associated with human and animal diseases. At the moment, the treatment of clostridial infections is based on use of antibiotics. However, due to the European ban on the use of antibiotics in livestock production, novel therapeutic strategies for treatment of these hardly curable infections have been evaluated. Hence, in this study the antimicrobial effect of newly designed probiotic culture consisted of natural isolates Lactobacillus helveticus BGRA43, Lactobacillus fermentum BGHI14 and Streptococcus thermophilus BGVLJ1-44 against Clostridium difficile and Clostridium perfringens was analyzed. RESULTS: The probiotic culture showed strong in vitro antimicrobial effect on C. difficile (human clinical isolate). In addition, individual strains and the probiotic combination exhibited immunomodulatory activity. The probiotic combination significantly increased the proliferation of GALT lymphocytes. At the other hand, none of the bacterial treatments (individual strains and the combination) induced the production of proinflammatory cytokines IL-6 and IL-1ß by intestinal epithelial cells, Caco-2. Interestingly, Caco-2 cells exposed to the probiotic combination produced significantly elevated amount of TGFß pointing to potential protecting effect of the probiotic. In addition, the results of field trial on spontaneously infected goats revealed reduction of C. perfringens in goats (below the detection threshold) after the probiotic treatment. CONCLUSIONS: The results of this study indicated that the novel probiotic deserves to be further investigated as a promising antimicrobial agent against C. difficile and C. perfringens.

Randomized clinical trial: efficacy of a food supplement, TRANSITECH, on healthy individuals with mild intermittent constipation.

BACKGROUND: Constipation is a common disorder in the general population and can be observed in healthy individuals. A natural product leading to an increase in bowel movements and decrease in colonic transit time (CTT), without bloating, could be useful for the patient's care. OBJECTIVES: To investigate the effects of TRANSITECH, a food supplement composed of plants and lactic ferments, on bowel movements, CTT and bloating. METHODS: A total of 100 healthy participants, presenting two to five stools per week, were selected and followed over a 6-day baseline period. They were randomly assigned to receive daily two tablets of TRANSITECH or placebo during 10 days. They were then followed up over 28 days after intervention. Participants daily recorded in a home questionnaire the characteristics of stools (frequency and consistency), and the importance of bloating during the preintervention period (from D-6 to D0), the intervention period (from D0 to D10) and the postintervention period (from D10 to D38). Their CTTs were also evaluated by following the propagation of radiopaque markers at D0 and D10. RESULTS: At D10, the food supplement group showed, compared with the placebo group, higher daily stool emission (0.95±0.50, 0.70±0.20, P<0.001), softer stool consistency (2.5±0.6 vs. 3.0±0.8, P<0.001) and lower CTT (33.8±28.2 vs. 56.4±36.2 h, P=0.01). The active group also showed a sustained increase in daily stool emissions observed at D38 compared with D0 (P=0.03). CONCLUSION: TRANSITECH is an efficient natural solution for the treatment of constipation. It increases the number of bowel movements, decreases the oroanal and segmental CTT, is well tolerated, and presents sustained effects after treatment completion.

Compromised Lactobacillus helveticus starter activity in the presence of facultative heterofermentative Lactobacillus casei DPC6987 results in atypical eye formation in Swiss-type cheese.

Nonstarter lactic acid bacteria are commonly implicated in undesirable gas formation in several varieties, including Cheddar, Dutch-, and Swiss-type cheeses, primarily due to their ability to ferment a wide variety of substrates. This effect can be magnified due to factors that detrimentally affect the composition or activity of starter bacteria, resulting in the presence of greater than normal amounts of fermentable carbohydrates and citrate. The objective of this study was to determine the potential for a facultatively heterofermentative Lactobacillus (Lactobacillus casei DPC6987) isolated from a cheese plant environment to promote gas defects in the event of compromised starter activity. A Swiss-type cheese was manufactured, at pilot scale and in triplicate, containing a typical starter culture (Streptococcus thermophilus and Lactobacillus helveticus) together with propionic acid bacteria. Lactobacillus helveticus populations were omitted in certain vats to mimic starter failure. Lactobacillus casei DPC6987 was added to each experimental vat at 4 log cfu/g. Cheese compositional analysis and X-ray computed tomography revealed that the failure of starter bacteria, in this case L. helveticus, coupled with the presence of a faculatively heterofermentative Lactobacillus (L. casei) led to excessive eye formation during ripening. The availability of excess amounts of lactose, galactose, and citrate during the initial ripening stages likely provided the heterofermentative L. casei with sufficient substrates for gas formation. The accrual of these fermentable substrates was notable in cheeses lacking the L. helveticus starter population. The results of this study are commercially relevant, as they demonstrate the importance of viability of starter populations and the control of specific nonstarter lactic acid bacteria to ensure appropriate eye formation in Swiss-type cheese.

Health-promoting properties exhibited by Lactobacillus helveticus strains.

Many strains belonging to lactobacilli exert a variety of beneficial health effects in humans and some of the bacteria are regarded as probiotic microorganisms. Adherence and capabilities of colonization by Lactobacillus strains of the intestinal tract is a prerequisite for probiotic strains to exhibit desired functional properties. The analysis conducted here aimed at screening strains of Lactobacillus helveticus possessing a health-promoting potential. The molecular analysis performed, revealed the presence of a slpA gene encoding the surface S-layer protein SlpA (contributing to the immunostimulatory activity of L. helveticus M 92 probiotic strain) in all B734, DSM, T80, and T105 strains. The product of gene amplification was also identified in a Bifidobacterium animalis ssp. lactis BB12 probiotic strain. SDS-PAGE of a surface protein extract demonstrated the presence of a protein with a mass of about 50 kDa in all strains, which refers to the mass of the S-layer proteins. These results are confirmed by observations carried with transmission electron microscopy, where a clearly visible S-layer was registered in all the strains analyzed. The in vitro study results obtained indicate that the strongest adhesion capacity to epithelial cells (HT-29) was demonstrated by L. helveticus B734, while coaggregation with pathogens was highly diverse among the tested strains. The percentage degree of coaggregation was increasing with the incubation time. After 5 h of incubation, the strongest ability to coaggregate with Escherichia coli was expressed by T104. The T80 strain demonstrated a significant ability to co-aggregate with Staphylococcus aureus, while DSM with Bacillus subtilis. For B734, the highest values of co-aggregation coefficient was noted in samples with Salmonella. The capability of autoaggregation, antibiotic susceptibility, resistance to increasing salt concentrations, and strain survival in simulated small intestinal juice were also analyzed.

Lactobacillus helveticus SBT2171 inhibits lymphocyte proliferation by regulation of the JNK signaling pathway.

Lactobacillus helveticus SBT2171 (LH2171) is a lactic acid bacterium with high protease activity and used in starter cultures in the manufacture of cheese. We recently reported that consumption of cheese manufactured using LH2171 alleviated symptoms of dextran sodium sulfate (DSS)-induced colitis in mice. In this study, we have examined whether LH2171 itself exerts an inhibitory effect on the excessive proliferation of lymphocytes. We found that LH2171 inhibited the proliferation of LPS-stimulated mouse T and B cells, and the human lymphoma cell lines, Jurkat and BJAB. Cell cycle analysis showed an accumulation of LH2171-treated BJAB cells in the G2/M phase. Further, phosphorylation of c-Jun N-terminal kinase (JNK) and c-Jun was reduced by LH2171 in BJAB cells. Subsequently, expression of cell division cycle 2 (CDC2), regulated by the JNK signaling pathway and essential for G2/M phase progression, was inhibited by LH2171. It was also demonstrated that intraperitoneal administration of LH2171 strongly alleviated symptoms of collagen-induced arthritis (CIA) in mice. These findings suggest that LH2171 inhibits the proliferation of lymphocytes through a suppression of the JNK signaling pathway and exerts an immunosuppressive effect in vivo.

Impact of emergency department probiotic treatment of pediatric gastroenteritis: study protocol for the PROGUT (Probiotic Regimen for Outpatient Gastroenteritis Utility of Treatment) randomized controlled trial.

BACKGROUND: The burden of acute gastroenteritis on children and their families continues to be enormous. Probiotics, defined as viable microbial preparations that have a beneficial effect on the health of the host, represent a rapidly expanding field. Although clinical trials in children with gastroenteritis have been performed, most have significant flaws, and guidelines do not consistently endorse their use. METHODS/DESIGN: PROGUT is a randomized, placebo-controlled, double-blind, five-center, Canadian, emergency department trial. Children aged 3 months to 48 months who present between November 2013 and June 2017 with <72 hours of gastroenteritis symptoms will be assessed for eligibility. A total of 886 children will be randomized (1:1 allocation via an internet based, third party, randomization service) to receive 5 days of a combination probiotic agent (Lactobacillus rhamnosus and L. helveticus) or placebo. All participants, caregivers, and outcome assessors will be blinded to group assignment. The study includes three key outcomes: 1) clinical - the development of moderate to severe disease following an emergency department (ED) evaluation that employs a validated clinical score (Modified Vesikari Scale); 2) safety - side effect; and 3) mechanism - fecal secretory immunoglobulin A levels. DISCUSSION: Definitive data are lacking to guide the clinical use of probiotics in children with acute gastroenteritis. Hence, probiotics are rarely prescribed by North American physicians. However, the following current trends obligate an urgent assessment: 1) probiotics are sold as food supplements, and manufacturers can encourage their use while their relevance has yet to be established; 2) North American and European government agencies remain concerned about their value and safety; 3) some institutions are now recommending the routine use of probiotics; and 4) parents of affected children are often providing probiotics. With probiotic consumption increasing in the absence of solid evidence, there is a need to conduct this definitive trial to overcome the limitations of prior work in this field. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01853124; first registered 9 May 2013.