Mikrobiologická detekce probiotických mikroorganismů ve fermentovaných mléčných výrobcích

Probiotic Bacteria: Selective Enumeration and Survival in Dairy Foods

Probiotics are living microorganisms that fall in the beneficial category, and confer health benefits for the host. Specifically, Lactic Acid Bacteria (LAB) cultures are used for the production of specific probiotic products. The aim of the present study was the isolation and categorization of probiotic bacteria from selected provincial yoghurt, and subsequently study of their probiotic properties through in vivo mice trial. A total of eight isolates were obtained from yoghurt, each two of Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus brevis, and Bifidobacterium spp. According to their physiological and biochemical assay, it was pragmatic that all the species from yoghurt were gram positive, endospore negative, catalase negative and non-motile which are the characteristics of usual probiotic bacteria. Sugar fermentation outline experiments using sixteen vital sugars ensured the presumptive identification of these four species from yoghurt samples. All species were resistant to synthetic gastric juice environment and able to endure artificial bile salts. All species from yoghurt showed good acceptance against low level of phenol and sodium chloride. Isolated probiotic bacteria also able to increase body weight, decrease blood cholesterol level and show antimicrobial activity in in vivo mice trial. The isolated and identified probiotic bacteria of present study could be further scrutinized for probiotic product development.

O leite de cabra é recomendado para pessoas intolerantes ao leite de vaca e/ou portadoras de desordens gastrintestinais. frozen yogurt elaborado a partir de iogurte de leite de cabra foi acrescido de 1% de prebiótico (inulina), 0,25% de cultura starter (Streptococcus thermophilus e Lactobacillus bulgaricus) e 0,25% de cultura probiótica (Bifidobacterium animalis e Lactobacillus acidophilus) para verificar seu potencial probiótico (após sete e 120 dias de armazenamento), sua qualidade físico-química e sua aceitação sensorial. Durante a estocagem, houve redução de células viáveis da flora microbiana, principalmente dos probióticos. Ainda assim, o produto apresenta potencialidade probiótica pela soma de B. animalis e L. acidophilus atingir o mínimo desejável até o fim do armazenamento. Os valores de extrato seco total (26,6±0,2%), proteína (3,0±0,2), gordura (2,6±0,1%), pH (5,5±0,01) e ácido láctico (0,2±0,01%) encontram-se semelhantes aos relatados em outros trabalhos para o mesmo produto. A avaliação sensorial foi realizada por 50 provadores não treinados em teste com escala hedônica de sete níveis e intenção de compra. O produto recebeu bons escores para aparência global, cor, aroma e sabor; já textura e sabor residual obtiveram menores índices de aceitação. Na intenção de compra, 61% dos avaliadores declararam que comprariam o produto, contra 39% que não comprariam. Nessas condições, demonstra-se a viabilidade de elaboração de frozen yogurt de leite caprino acrescido de pre- e probióticos.

The objective of the present work was to study probiotic fermented milks during fermentation process and cold storage.Two strains of probiotic bacteria were used: Lactobacillus acidophilus (LA) and Bifidobacterium animalis subsp.lactis (BL).The yogurt culture Lactobacillus bulgaricus (LB) was used as control.All strains were employed in coculture with the starter Streptococcus thermophilus (ST).Commercial skimmed milk powder was diluted in distilled water (12.4g100g -1 ) and heat treated.All inoculated milks were incubated for fermentation at 42°C in a water bath until pH 4.50 was reached.Chemical changes during fermentation were followed by measuring: V m (maximum acidification rate that measures the decrease of pH units per minute and the values are expressed as mUpH/min), t Vmax (time to achieve the maximum acidification rate, in h), t pH5,0 (time to achieve pH5.0, in h) and t pH4.5 (time necessary to reach pH 4.5, in h).Rheological behavior was determined at d1 and firmness, pH and viability were followed until 28 days of storage at 4ºC.Fermentation time for probiotic cultures was longer than for yogurt culture.pH decreased and firmness increased during storage.The main change occurred in the first week.Probiotic bacteria grow during fermentation.ST dominated over the other strains and remained stable during all storage period.B. lactis and L. bulgaricus attain the final storage period stable.L. acidophilus, however, decreased before 14 days of storage and at d 28 doesn't fit the minimum requirements to achieve beneficial properties to health.

SummaryThe antimicrobial potential of whey protein isolate (WPI) edible films containing 1–4% (v/v) Zataria multiflora Boiss. essential oil (EO) on food‐borne pathogenic bacteria (Escherichia coli, Salmonella enteritidis, Staphylococcus aureus and Bacillus cereus) and probiotic bacteria (Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus plantarum and Lactobacillus casei subsp. casei) was evaluated. WPI films incorporated with 2% (v/v) of this EO inhibited the growth of all tested pathogenic bacteria and gram‐negative bacteria were more sensitive than gram‐positive bacteria. Incorporation of the EO at higher than 2% (v/v) showed significant antimicrobial effects (P < 0.05) for S. enteritidis and L. acidophilus. The growth of all probiotic lactic acid‐producing bacteria also inhibited when 2% of the EO was added. Comparison of an image processing‐based method with conventional method for measuring of inhibitory effects of edible films exhibited high correlations (R2 ≥ 0.876) between the two methods. These results revealed that Z. multiflora Boiss. EO is a good antimicrobial additive for some food applications when included into WPI edible films.

The aim of this study was to evaluate the changes in the lipid profile, especially in conjugated linoleic acid (CLA), in 12 cream cheese batches with different prebiotic (inulin) and probiotic (Bifidobacterium animalis and Lactobacillus acidophilus) concentrations stored for 45 days at 8 ± 0.5 °C and analyzed every 15 days. A Central Rotational Composite Design was used to establish the prebiotic and probiotic concentrations. The effect of the pre- and probiotic concentrations on CLA contents (mg g−1 of fat) was verified by plotting the response surface. The linear, quadratic, and interaction coefficients of the multiple linear regression for both prebiotic and probiotics were not significant (p > 0.05). No significant changes were observed neither in the lipid profile nor in the CLA content among the different batches, in which fatty acid composition and CLA concentrations were similar to the milk used in the preparation of the cream cheese and also to the control batch.

Inflammatory bowel disease, a dysregulated host‐microbiota interaction: Are probiotics a new therapeutic option?

Soymilk is a good source of proteins and health-promoting isoflavones, but it contains oligosaccharides that cause flatulence. Fermenting it with probiotic bacteria may reduce the oligosaccharides and enhance its health benefits.The present study determined the growth of different lactic acid bacteria (LAB) in soymilk obtained from soybean varieties grown in Rwanda and the effect of fermentation on oligosaccharides that cause flatulence (stachyose, raffinose and verbascose), and antioxidant activity of fermented soybean milk. After fermentation at 30°C for 24 hours, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus reuteri, Lactobacillus rhamnosus, Lactococcus cremoris and Lactobacillus casei attained around 8 log CFU/ml, which is sufficient for probiotic effects. However, only L. reuteri, L. brevis and L. plantarum caused sufficient drop in pH and increase in viscosity characteristic of a good fermented product. Soymilk from different soybean varieties did not show significant differences in the growth of these three LAB.These LAB reduced content of oligosaccharides and total polyphenols, but increased antioxidant activity in soymilk, which translate into health benefits of fermented soybean products.

One of the primary risk factors for cardiovascular diseases (CVDs) that caused deaths is hypercholesterolemia, which can be identified by high levels of total cholesterol, low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL). Dietary interventions, involving the consumption of soy protein, have been indicated to be effective in reducing LDL cholesterol levels. Edamame, a kind of soybean, is a potential source of soy protein that could be processed into functional foods. The aim of the research was to evaluate the chemical and sensory properties of edamame yoghurt fermented with lactic acid bacteria and probiotic bacteria, potentially contributing to a cholesterol-lowering benefit. The research methodology was a two-factor Randomized Block Design (RBD). The edamame yoghurt was made by combining edamame juice, skim milk powder, and sugar, followed by heat (80-85 °C for 15 minutes), and cooling to 45 °C. The mixture was then inoculated with a combination of lactic acid bacteria (Lactobacillus bulgaricus and Streptococcus thermophilus) and probiotic bacteria (Bifidobacterium bifidum and Lactobacillus acidophilus). Fermentation proceeded at 37 °C for 7 hours. The pH, total titratable acidity, lactic acid bacteria count, and soluble protein content were analysed. Sensory properties were evaluated using preference and hedonic tests. The results exhibited that the combination of bacterial cultures significantly affected (p<0.05) pH, total soluble protein, and sensory properties of the yoghurt. Bifidobacterium bifidum led to higher acidity pH (3.73-3.78), while Lactobacillus acidophilus resulted in the lowest titratable acidity (0.55-0.63%). The combination of Lactobacillus bulgaricus and Streptococcus thermophilus improved flavor, texture, and fermentation efficiency. The yoghurt’s texture was smooth due to proteolytic activity by lactic acid bacteria. Edamame yoghurt's green color fades during fermentation, and its aroma is less favoured according to panelists, but its creamy texture and mildly acidic taste make it appealing overall. Edamame yoghurt, a source of soy protein fermented with lactic acid and probiotic bacteria, shows potential for cholesterol reduction.

An easy and robust method of preparation of capsules for delivering probiotic bacteria by a 3D bioprinting

Probiotic lactic acid bacteria (Lactobacillus acidophilus HN017, Lactobacillus rhamnosus HN001 and Bifidobacterium lactis HN019) have no adverse effects on the health of mice

Introduction: Supplementation of probiotics, and supplementation of zinc, during acute gastroenteritis in children has positive effects on diarrhea duration and severity. Our study aim was to evaluate the effectiveness of a new diet enriched with zinc and probiotic bacteria in the treatment of acute gastroenteritis in young children. Methods: In a double blind prospective study, 65 children aged 6–12 months were randomized to receive 6 ×109 of streptococcus Thermophilus, Bifidobacterium Lactis, Lactobacillus Acidophilus (2 ×109 of each strain), 10 mg of Zinc/day and 0.3 grams of fructo-oligosaccharides in the supplemented group (n=33) or placebo (n=32) given as the same amount and composition of a soy protein based rice cereal. For each child age, sex, weight, degree of dehydration, the presence of fever or vomiting, stool frequency and consistency were recorded daily until diarrhea resolution. Results: Diarrhea resolution occurred after 1.43 ± 0.71 days in the supplemented group vs. 1.96 ± 1.24 in the control group (p=0.017). In the subset of children who presented with vomiting, time to vomiting resolution was 0.27±0.59 vs. 0.81±0.91 days in the supplemented and controlgroups respectively (p=0.06). On day 3, there was only 1 child with wattery stools in the supplemented group compared with 10 children in the control group (p=0.02). However, there was no difference in stool frequency between the study groups. Conclusion: The supplementation of a cereal containg streptococcus Thermophilus, Bifidobacterium Lactis, Lactobacillus Acidophilus and zinc shortens the severity and duration of acute gastroenteritis in children six to twelve months of age.

The aim of the present study was to investigate the phenotypic and genotypic antimicrobial resistance and the transferability of resistance markers in 87 lactic acid bacterial strains recovered from fermented milk products obtained from different areas of China. The isolates were identified as 21 Lactobacillus bulgaricus, 8 Lactobacillus casei, 6 Lactobacillus rhamnosus, 3 Lactobacillus paracasei, 2 Lactobacillus acidophilus, and 47 Streptococcus thermophilus strains. High levels of intrinsic resistance were revealed among the tested species. The following resistance genes were detected in strains isolated from fermented milk products: tet(M) in two L. bulgaricus and two S. thermophilus isolates, strA and strB in nine and seven S. thermophilus isolates, respectively; sul1 in six L. bulgaricus and seven S. thermophilus isolates, sul2 in one S. thermophilus isolate, aac(6')-aph(2″) in two L. bulgaricus isolates, and aph(3″)-II and aph(3″)-III in one S. thermophilus and two L. bulgaricus isolates, respectively. Transfer of the monitored antibiotic resistance genes was not observed in the filter mating assays of this study. To our knowledge, the strA, strB, sul1, sul2, and aph(3″)-II genes in S. thermophilus, and the sul1 and aac(6')-aph(2″) genes in L. bulgaricus were identified for the first time. These results indicate the potential risks posed by lactic acid bacteria (LAB) in fermented milk products in expanding the antibiotic resistance gene reservoir and transferring antibiotic resistance genes among bacteria. Further investigations are required to identify the potential sources of contamination and the dissemination routes of antibiotic resistance genes among LAB in fermented milk products.

Glycosphingolipids (GSL) are part of intestinal epithelial cell (IEC) membranes and are composed by a sugar moiety attached to ceramide. GSL contributes to many cellular functions, including protein sorting, cell adhesion, cell‐cell signaling and apoptosis.Probiotics are commensal bacteria with the ability to modify cellular processes in a beneficial way. We have shown that a probiotic preparation, S. thermophilus (ST) and L. acidophilus (LA), has the ability in vitro and in vivo to decrease chloride secretion and diarrhea by regulating kinase signaling and levels of ion transport proteins in IEC. Our ST strain expresses bacterial sphyngomyelinase , whereas LA does not. We hypothesized that ST/LA may regulate chloride secretion by altering GSL signaling in IEC. T84 and HT29/cl.19A cells were infected with enteroinvasive E.coli (EIEC) and S.dublin (SD), and were treated with wild type probiotics or mutated ST and/or LA. While wild type ST/LA, LA and ST alone were able to reverse the effects of EIEC and SD on chloride secretion in IEC, a ST strain carrying a mutation of the SMase gene and SMase‐negative commensal Streptococci had no effect on the dysregulated ion transport after pathogens infection. This effect was mediated by ERK1,2 and JNK, as shown by kinases inhibitors treatment. Moreover, we observed significantly altered CFTR and NKCC1 function and cellular distribution after treatment with ST/LA and LA and ST alone after EIEC and SD infection. Our findings provide insight on mechanisms of probiotics effects and on GSL cell signaling in the gut.

Background/AimsWe aim to evaluate the differences in the microbiome of responders and non-responders, as well as predict the response to probiotic therapy, based on fecal microbiome data in patients with diarrhea-predominant irritable bowel syndrome (IBS-D).MethodsA multi-strain probiotics that contains Lactobacillus acidophilus (KCTC 11906BP), Lactobacillus plantarum (KCTC11867BP), Lactobacillus rhamnosus (KCTC 11868BP), Bifidobacterium breve (KCTC 11858BP), Bifidobacterium lactis (KCTC 11903BP), Bifidobacterium longum (KCTC 11860BP), and Streptococcus thermophilus (KCTC 11870BP) were used. Patients were categorized into probiotic and placebo groups, and fecal samples were collected from all patients before and at the end of 8 weeks of treatment. The probiotic group was further divided into responders and non-responders. Responders were defined as patients who experienced adequate relief of overall irritable bowel syndrome symptoms after probiotic therapy. Fecal microbiota were investigated using Illumina MiSeq and analyzed using the EzBioCloud 16S database and microbiome pipeline (https://www.EZbiocloud.net).ResultsThere was no significant difference in the alpha and beta diversity between the responder and non-responder groups. The abundances of the phylum Proteobacteria and genus Bacteroides significantly decreased after probiotic treatment. Bifidobacterium bifidum, Pediococcus acidilactici, and Enterococcus faecium showed a significantly higher abundance in the probiotic group after treatment compared to the placebo group. Enterococcus faecalis and Lactococcus lactis were identified as biomarkers of non-response to probiotics. The abundance of Fusicatenibacter saccharivorans significantly increased in the responders after treatment.ConclusionsProbiotic treatment changes some composition of fecal bacteria in patients with IBS-D. E. faecalis and L. lactis may be prediction biomarkers for non-response to probiotics. Increased abundance of F. sccharivorans is correlated to symptom improvement by probiotics in patients with IBS-D.