Probiotic lactobacilli in a semi-soft cheese survive in the simulated human gastrointestinal tract

The Effect of Delivery Matrix on Bifidobacterium animalis subsp. lactis HN019 Survival through In Vitro Human Digestion

Bifidobacterium animalis subsp. lactis HN019 is a probiotic with several documented human health benefits. Interest in probiotics has led to the development of new formats that probiotics, including HN019, can be supplemented into. In this study, we looked at common HN019 formats such as frozen culture and freeze-dried powder as well as supplementing it into the following food matrices: yogurts (dairy, soy, and oat based), xanthan gum-based tablets, pulpless orange juice, whey sports drink, and dark chocolate (70% cocoa). In this work, our aim was to investigate whether the food matrix that carried HN019 via simulated human digestion (a dual model system mimicking both upper and lower gastrointestinal digestion) influenced probiotic delivery. To that end, we validated and used a real-time qPCR assay to detect HN019 after simulated digestion. In addition, we also measured the effect on a panel of metabolites. After simulated digestion, we were able to detect HN019 from all the matrices tested, and the observed changes to the metabolite profile were consistent with those expected from the food matrix used. In conclusion, this work suggests that the food matrix supplemented with HN019 did not interfere with delivery to the colon via simulated human digestion.

Fermented dairy products as delivery vehicles of novel probiotic strains isolated from traditional fermented Asian foods

The screening of novel probiotic strains from various food sources including fruits, vegetables, herbs, and traditional fermented foods, have been of growing concern recently. Most of these potential probiotic lactic acid bacteria isolates were distinguished from the commercial probiotics based on multiple therapeutic effects and functionalities. Recent in vitro and in vivo investigates have also verified the usage of probiotics to lower the risk of diseases. Application of these novel strains in fermented dairy products is also an emerging trend to improve the physical and quality characteristics, functional properties, and safety of dairy products. Moreover, since dairy products are one of the highest consumed products in the globe, the dispatch channels for fermented dairy products are already established. Therefore, incorporating novel probiotic strains into fermented dairy products might be the most feasible approach for their delivery. In this context, our aim is to discuss the feasibility of dairy products as delivery vehicles for novel probiotic strains. Thus, we summarize the scientific evidence that points to a dynamic future for the production of fermented dairy-based probiotics.

Investigations on Metabolic Changes in Beagle Dogs Fed Probiotic Queso Blanco Cheese and Identification of Candidate Probiotic Fecal Biomarkers Using Metabolomics Approaches

Intake of probiotic cheese improves the intestinal health of humans and animals. However, metabolic changes in the intestines of dogs in response to the ingestion of probiotic cheese have not been evaluated. Thus, we aimed to determine the metabolic changes in healthy beagle dogs fed queso blanco cheese with added Lactobacillus reuteri KACC 92293 and Bifidobacterium longum KACC 91563 (QCLB) and to identify potential fecal biomarkers to distinguish the metabolic changes based on intake of probiotic cheese through metabolomics approaches. The dogs were randomly divided into three groups and fed a regular diet without any cheese (control), a diet with queso blanco cheese (QC), or one with QCLB for eight weeks. The concentrations of acetic, propionic, and 4-aminobutyric acids were increased in the QCLB group compared to those in the control group. Additionally, higher levels of propionic acid and lower levels of xylose were found in the QCLB group compared to those in the QC group. This is the first report on the identification of metabolic changes in beagle dogs fed queso blanco cheese with added L. reuteri KACC 92293 and B. longum KACC 91563. We also found that metabolomics approaches can be useful for identifying potential fecal markers in dogs fed probiotic cheese.

Dose-Response Recovery of Probiotic Strains in Simulated Gastro-Intestinal Passage

The probiotic definition stipulates “adequate amounts”. Here, we investigated the metabolic output and recovery rate of probiotic strains using a simulated upper gastro-intestinal passage and colonic fermentation. Two different doses, 7 × 10⁹ colony forming units (CFU) and 7 × 10¹⁰ CFU, of a probiotic mixture (Bifidobacterium lactis Bl-04, Lactobacillus acidophilus La-14, Lactobacillus paracasei Lpc-37, and Lactobacillus plantarum Lp-115) or placebo were tested. The four strains were quantified by qPCR and the metabolites analyzed by gas chromatography. There was a dose-response in the detection of all four strains. There was a slightly larger increase between the two doses for L. paracasei Lpc-37 as compared with the other strains; this may suggest a greater robustness of this strain. Compared with the placebo, the high dose simulations generated more propionic acid and a higher total of short chain fatty acids (SCFA). Higher doses of a species are required to reach measurable increases above the baseline level of this species.

Characterization of cottage cheese using Weissella cibaria D30: Physicochemical, antioxidant, and antilisterial properties

This study aimed to evaluate the potential of Weissella cibaria D30 as an adjunct culture in cottage cheese, including an assessment of antioxidant, antilisterial, and compositional parameters. Cottage cheese samples were manufactured using a commercial starter culture and probiotic strains Lactobacillus rhamnosus GG (GG) or W. cibaria D30 (W) and without probiotic (control). Samples were stored at 4 ± 1°C for 28 d. Bacterial cell counts (log cfu/g) of control, GG, and W samples were counted at 0, 7, 14, 21, and 28 d. Counts of W. cibaria D30 in the W samples remained at 6.85 log cfu/g after 28 d. Total solids, fat, protein, ash, and pH were measured and no significant differences were observed in compositional parameters or pH after 28 d of storage in all cheeses except those inoculated to Listeria monocytogenes. To measure the antilisterial effect, Listeria monocytogenes was inoculated into the cottage cheese samples and bacterial cell counts were obtained at 0, 6, 12, 24, 48, 72, 96, 120, and 144 h. Listeria monocytogenes counts were less than the analytical limit of detection (<10 cfu/g) in the inoculated GG and W samples, whereas the counts of L. monocytogenes in the inoculated control sample remained at 3.0 log cfu/g after 144 h. We used the DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging activity assays to assess antioxidant activity: GG and W samples exhibited significant increases in antioxidant activity compared with the control sample. These results indicate that W. cibaria D30 has potential as an adjunct culture in the dairy industry.

Simulating colonic survival of probiotics in single-strain products compared to multi-strain products

Background: Probiotic formulations can be single- or multi-strain. Commercially, multi-strain preparations have been suggested to have improved functionality over single-strain cultures. Probiotics are often tested as single-strain preparations but may subsequently be commercially formulated as multi-strain products.

Objective: The aim of this study was to determine what happens at the site of action, the intestine, with probiotics as single- compared to multi-strain preparations. The human gastrointestinal tract contains a broad mixture of different microbes which may affect the survival of different probiotics in different ways.

Design: The current study was performed to evaluate, in an in vitro colon simulation, whether probiotics influence each other’s survival when they are taken as a combination of several strains (HOWARU Restore; Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, Bifidobacterium lactis Bl-04 and B. lactis Bi-07) compared to the strains as single preparations.

Results: All strains could be detected after the colon simulations and there were no substantial differences in levels of the same strain when comparing single- and multi-strain products.

Conclusions: It can be concluded that probiotics do not have an antagonistic effect on each other’s survival when used in a multi-strain product compared to a single-strain product, at least within a microbiota in a simulated colonic environment.

Probiotic Strains Influence on Infant Microbiota in the In Vitro Colonic Fermentation Model GIS1

The main goal of our study was to evaluate the effect of the individual administration of five lyophilized lactic acid bacteria strains (Lactobacillus fermentum 428ST, Lactobacillus rhamnosus E4.2, Lactobacillus plantarum FCA3, Lactobacillus sp. 34.1, Weissella paramesenteroides FT1a) against the in vitro simulated microbiota of the human colon using the GIS1 system. The influence on the metabolic activity was also assessed by quantitative determination of proteins and polysaccharides at each segment of human colon. The obtained results indicated that the lactic acid bacteria L. rhamnosus E4.2 and W. paramesenteroides FTa1 had better efficiency in synthesising exopolysaccharides and also a better probiotic potential and therefore could be recommended for use in probiotics products or food industry.

Immunomodulatory activity of two potential probiotic strains in LPS-stimulated HT-29 cells

The relative expression of mucin, pro- and anti-inflammatory genes besides other signaling molecules in HT-29 cells by two test probiotic strains of Lactobacillus plantarum Lp9 and Lp91 and the reference strain L. plantarum 5276 was evaluated by RT-qPCR using Relative Expression Software Tool qBase-Plus under in vitro simulated gut conditions. Ten house keeping genes were evaluated by using geNorm 3.4 excel based application. The most stable genes were RPL27, ACTB and B2M which were subsequently used for calculating the normalization factor. Under pretreatment conditions (4 h probiotic treatment, followed by lipopolysaccharide challenge for 3 h), all the three strains evoked downregulation of IL-8 expression by ~100 %, while in case of TNF-α, the downregulation of the relative gene expression was at the rate of 98.2, 93.8 and 98.0 % with Lp5276, Lp9 and Lp91, respectively, under the same set of conditions. Lp91 evoked maximum downregulation of IL12p35 and IFN-γ with corresponding fold reduction in relative expression of the two genes by 96.5 and 96.7 % during pre-treatment conditions. However, IL-10 and IFN-α were significantly upregulated to the extent of 8.13 ± 0.36 and 2.62 ± 0.14 fold by Lp91 under the same conditions. Lp9 and Lp91 were also quite effective in inducing the expression of Cox-1 and Cox-2 in HT-29 cells as can be reflected from their ratios, i.e., 5.90 and 6.50 (under pretreatment conditions); 3.79 and 4.36 (under co-culture conditions). Thus, the two putative indigenous L. plantarum strains Lp9 and Lp91 demonstrated immunomodulating functions in HT-29 cells at significant levels under different experimental conditions.

Comparative analysis of the gene expression profile of probiotic Lactobacillus casei Zhang with and without fermented milk as a vehicle during transit in a simulated gastrointestinal tract

Studies have found that the survival of probiotics could be strongly enhanced with dairy products as delivery vehicles, but the molecular mechanism by which this might occur has seldom been mentioned. In this study, microarray technology was used to detect the gene expression profile of Lactobacillus casei Zhang with and without fermented milk used as a delivery vehicle during transit in simulated gastrointestinal juice. Numerous genes of L. casei Zhang in strain suspension were upregulated compared to those from L. casei Zhang in fermented milk. These data might indicate that L. casei Zhang is stimulated directly without the protection of fermented milk, and the high-level gene expression observed here may be a stress response at the transcriptional level. A large proportion of genes involved in translation and cell division were downregulated in the bacteria that were in strain suspension during transit in simulated intestinal juice. This may impede protein biosynthesis and cell division and partially explain the lower viability of L. casei Zhang during transit in the gastrointestinal tract without the delivery vehicle.

Probiotic cheese containing Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus NCFM® modifies subpopulations of fecal lactobacilli and Clostridium difficile in the elderly

Aging is associated with alterations in the intestinal microbiota and with immunosenescence. Probiotics have the potential to modify a selected part of the intestinal microbiota as well as improve immune functions and may, therefore, be particularly beneficial to elderly consumers. In this randomized, controlled cross-over clinical trial, we assessed the effects of a probiotic cheese containing Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus NCFM on the intestinal microbiota and fecal immune markers of 31 elderly volunteers and compared these effects with the administration of the same cheese without probiotics. The probiotic cheese was found to increase the number of L. rhamnosus and L. acidophilus NCFM in the feces, suggesting the survival of the strains during the gastrointestinal transit. Importantly, probiotic cheese administration was associated with a trend towards lower counts of Clostridium difficile in the elderly, as compared with the run-in period with the plain cheese. The effect was statistically significant in the subpopulation of the elderly who harbored C. difficile at the start of the study. The probiotic cheese was not found to significantly alter the levels of the major microbial groups, suggesting that the microbial changes conferred by the probiotic cheese were limited to specific bacterial groups. Despite that the administration of the probiotic cheese to the study population has earlier been shown to significantly improve the innate immunity of the elders, we did not observe measurable changes in the fecal immune IgA concentrations. No increase in fecal calprotectin and β-defensin concentrations suggests that the probiotic treatment did not affect intestinal inflammatory markers. In conclusion, the administration of probiotic cheese containing L. rhamnosus HN001 and L. acidophilus NCFM, was associated with specific changes in the intestinal microbiota, mainly affecting specific subpopulations of intestinal lactobacilli and C. difficile, but did not have significant effects on the major microbial groups or the fecal immune markers.

Synbiotic effects of lactitol and Lactobacillus acidophilus NCFM™ in a semi-continuous colon fermentation model

The effects of Lactobacillus acidophilus NCFM™, lactitol, and the combination of lactitol and L. acidophilus NCFM™ were studied with a semi-continuous colon fermentation simulation; consisting of compartments mimicking, ascending, transverse, descending and sigmoid colon and their conditions with faecal inoculation. L. acidophilus NCFM™ was detected throughout the colon simulator. Lactitol was utilised early on by the microbes in the proximal part of the simulator. Lactitol increased the total numbers of microbes and bifidobacteria, and decreased clostridia cluster IV, while L. acidophilus NCFM™ alone decreased the numbers of clostridia cluster XIV. Combination treatment increased the numbers of bifidobacteria. Furthermore, concentrations of acetic acid, butyric acid and the sum of total short-chain fatty acids were increased by both lactitol-including treatments. The treatment with L. acidophilus NCFM™ alone increased the concentration of propionic acid and butyric acid. L. acidophilus NCFM™ tended to increase the total concentrations of biogenic amines, while lactitol suppressed production of biogenic amines also in the presence of L. acidophilus NCFM™. True synergistic effects are suggested in stimulation of the production of butyrate, an important microbial metabolite for colon health. In conclusion, lactitol as well as the combination of lactitol and L. acidophilus NCFM™ were found to exhibit complementary beneficial effects on the colon microbial composition and activity.

Probiotics and immunosenescence: cheese as a carrier

Oral intake of specific probiotics has been reported to enhance the immunity of the elderly. Earlier studies have used milk or yoghurt as a probiotic carrier. We chose a commercial probiotic cheese to evaluate its potential as a probiotic food. Thirty-one healthy elderly volunteers (21 female, 10 male) aged from 72 to 103 (median 86) consumed a commercial probiotic cheese containing approximately 10(9) CFU day(-1) of Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus NCFM. The 4-week probiotic intervention was preceded by a 2-week consumption of probiotic-free cheese (run-in) and followed by a 4-week wash-out period with the same control cheese. The cytotoxicity of peripheral blood mononuclear cells (PBMCs), the relative numbers of natural killer (NK) and NKT cells in the total PBMCs, and phagocytic activity were assessed. Consumption of the probiotic cheese significantly increased the cytotoxicity of NK cells. A significant increase in phagocytosis was observed for both the control and the probiotic cheese. Cheese was found to be an effective carrier for the study of probiotics, and daily consumption of the probiotic enhanced parameters of innate immunity in elderly volunteers. It remains to be determined whether this enhancement correlates with a beneficial effect on the health of the elderly population.