Survival of Lactobacillus casei (LC-1) adhered to prebiotic vegetal fibers

Viability and stability evaluation of microencapsulated Lactobacillus reuteri in polysaccharide-based bionanocomposite

Microencapsulation is one of the most important methods to enhance the survival of bacteria when exposed to various harsh conditions. The present study evaluated the viability of L. reuteri ATCC 23272 microencapsulated in polysaccharide-based bionanocomposite. Inulin, polydextrose, and pectin were utilized as prebiotics, and magnesium oxide nanoparticles (MgO NPs) as reinforcing agent in the microgel structure. The composition of bionanocomposite was optimized using the simplex-lattice mixture method. Bionanocomposite optimal formulation was achieved by combining 91.6 % inulin and 8.4 % pectin in the presence of MgO NPs. L. reuteri prebiotic score (1.33) and E. coli (1.08), extrusion efficiency (97.57 %), viability after drying (99.37 %), and viability in simulated gastrointestinal conditions (SGI) (91.74 %) were obtained. Not using MgO NPs in the optimal composite structure caused a decrease of 2.14 log CFU/g in SGI. During 28 days of storage of bacteria at 4 and 25 °C, respectively, a reduction of 2.56 and 3.04 log CFU/g was observed for free cells compared to encapsulated cells. SEM, FTIR, and XRD analyses were performed on ingredients and microcapsules with and without bacteria. The results exhibited that the optimal bionanocomposite could be used as a beneficial encapsulation system to improve the performance of probiotics in harsh conditions.

Proteomic Analysis of Milk Fat Globule Membrane Protein Modulation of Differently Expressed Proteins in Lactobacillus plantarum under Bile Salt Stress

Tolerance to bile stress is a crucial property for lactic acid bacteria (LAB) to survive in the gastrointestinal tract and exert their beneficial effects. Whey powder enriched with milk fat globule membrane proteins (M-WPI) as a functional component is protective for strains under stress conditions. The current study investigated the key mechanisms of action involved in Lactobacillus plantarum (L. plantarum) CGMCC 23701 survival in the presence of bile and the protective mechanism of M-WPI. According to proteomic analysis (proteomics), there could be several reasons for the greater protective effect of M-WPI. These include promoting the synthesis of fatty acids and peptidoglycans to repair the structure of the cell surface, regulating the metabolism of carbohydrates and amino acids to release energy and produce a range of precursors, enabling the expression of the repair system to repair damaged DNA, and promoting the expression of proteins associated with the multidrug efflux pump, which facilitates the exocytosis of intracellular bile salts. This study helps us to better understand the changes in proteome of L. plantarum CGMCC 23701 under bile salt stress and M-WPI protection, which will provide a new method for the protection and development of functional LAB.

The probiotic Lacticaseibacillus paracasei strain Shirota (LcS) in a fermented milk beverage survives the gastrointestinal tract of generally healthy U.S. Adults

The probiotic strain Lacticaseibacillus paracasei (previously Lactobacillus casei) strain Shirota (LcS) has demonstrated its survivability in the gastrointestinal tract across populations in different countries. The objective of this study was to validate this survivability in the United States, where evidence is lacking. Faecal samples were collected from 26 healthy individuals (age: 32.0 ± 5.9 years) at baseline, after 7 and 14 days of daily consumption of 80 mL fermented milk containing 108 colony forming units (CFU) LcS/mL, and after a subsequent 14-days of no product consumption. Live LcS counts significantly (p < 0.001) increased after 7 and 14 days of product consumption (6.37 ± 1.18 and 5.24 ± 1.81 log10 CFU/g faeces, respectively) and returned to baseline in 87% of participants. These results indicate LcS survives passage through the gastrointestinal tract of generally healthy U.S. adults, providing support for its uniquely accumulated evidence of universal survival capacity in the gastrointestinal tract.

Use of Highly Dispersed Silica in Biotechnology of Complex Probiotic Product Based on Bifidobacteria

Background. The probiotics immobilization technology is one of the most effective ways for controlled and continuous delivery of viable cells into the intestine. It is well known that multifaceted physiological roles of bifidobacteria are to normalize and stabilize the microbiocenosis, to form intestine colonization resistance, to synthesis amino acids, proteins and vitamins, to maintain non-specific resistance of the organism and so all. Such a wide range of positive effects on the macroorganism allows us to consider bifidobacteria as a basis for functional immobilized healthcare products development. Objective. Taxonomic position determination of the Bifidobacterium longum strain selected for immobilization, study of the viability of this bifidobacteria strain in a complex probionic product based on highly dispersed silica in simulated gastrointestinal tract's conditions and after freeze-drying. Methods. The production strain Bifidobacterium longum IMV B-7165 from the Institute of Food Resources of the National Academy of Agrarian Sciences of Ukraine collection of industrial strains has been used in the study. It was isolated from the healthy human infant's gastrointestinal tract. Commonly used bioinformatics, microbiological, biotechnological and statistical methods have been applied. Results. The best alignments for the sequence of bifidobacteria isolate "4202" 16S rRNA (it was previously deposited as Bifidobacterium longum IMV B-7165) and classic dendrograms based on these results were performed. According to the results of microscopic studies of samples of microorganisms with highly dispersed silica products ("Enterosgel", "Sillard P" and "Toxin.Net") it was found that the immobilization of the Streptococcus thermophilus and bifidobacteria cultures did not differ fundamentally. To study the immobilization effect on the bifidobacteria preservation and properties the following carriers were used: "Enterosgel", "Toxin.NET" and "Sillard P". The survival of immobilized bifidobacteria was further studied in simulated gastrointestinal conditions: immobilized cells are better protected from acid and bile, although with increasing acidity, survival decreases in both control and immobilized cells. Conclusions. The taxonomic position of a bifidobacterial isolate from the healthy human infants used in immobilization studies was clarificated (Bifidobacterium animalis subsp lactis). Under the simulated conditions of the upper gastrointestinal tract in the case of acid and bile impact, the best survival was demonstrated by immobilized cultures of bifidobacteria together with the Enterosgel sorbent (a content of 10% by weight of the culture). The survival of immobilized preparations after freeze-drying was slightly reduced in the case of immobilization on the "Enterosgel" and "Toxin.NET" samples of enterosorbents (a content from 15% to 25% by weight of the culture). The best results were observed in the case of immobilization of bifidobacteria with 5% content of the "Toxin.NET" enterosorbent (enterosgel + inulin).

Identification of WxL and S-Layer Proteins from Lactobacillus brevis with the Ability to Bind Cellulose and Xylan

Xylanase releases xylo-oligosaccharides from dietary xylan, which stimulate the growth of the gut bacteria lactobacilli. Many lactobacilli adhere to dietary fibers, which may facilitate the assimilation of xylo-oligosaccharides and help them gain competence in the gut, but the underlying mechanisms remain elusive. Herein we report, from the highly abundant transcripts of Lactobacillus brevis cultured in wheat arabinoxylan supplemented with a xylanase, the identification of genes encoding four putative cell-surface WxL proteins (Lb630, Lb631, Lb632, and Lb635) and one S-layer protein (Lb1325) with either cellulose- or xylan-binding ability. The repetitively occurring WxL proteins were encoded by a gene cluster, among which Lb630 was chosen for further mutational studies. The analysis revealed three aromatic residues (F30, W61, and W156) that might be involved in the interaction of the protein with cellulose. A homology search in the genome of Enterococcus faecium identified three WxL proteins with conserved counterparts of these three aromatic residues, and they were also found to be able to bind cellulose and xylan. The findings suggested a role of the cell-surface WxL and S-layer proteins in assisting the cellular adhesion of L. brevis to plant cell wall polysaccharides.

Growth-Promoting Effect of Cava Lees on Lactic Acid Bacteria Strains: A Potential Revalorization Strategy of a Winery By-Product

The growing trend of circular economy has prompted the design of novel strategies for the revalorization of food industry by-products. Cava lees, a winery by-product consisting of non-viable cells of Saccharomyces cerevisiae rich in β-glucans and mannan-oligosaccharides, can be used as a microbial growth promoter, with potential food safety and health applications. The aim of this study was to assess in vitro the effect of cava lees on the growth of 21 strains of lactic acid bacteria (LAB) species commonly used as starter cultures and/or probiotics. Firstly, 5% of cava lees was selected as the most effective amount for enhancing microbial counts. After screening different LAB, statistically significantly (p < 0.05) higher microbial counts were found in 12 strains as a consequence of cava lees supplementation. Moreover, a greater and faster reduction in pH was observed in most of these strains. The growth-promoting effects of cava lees on LAB strains supports the potential revalorization of this winery by-product, either to improve the safety of fermented products or as a health-promoting prebiotic that may be selectively fermented by probiotic species.

KAVITA. A Study on Suitable Non Dairy Food Matrix for Probiotic Bacteria - A Systematic Review

Fermentation by probiotic lactic acid bacteria makes food beneficial to the gut and has thepotential to be therapeutic. Most probiotic products in the market are dairy based even asthere is a growing demand for vegan probiotic foods. Though many studies on plant foods as a medium for probiotics havebeen carried out, only a few have been successful. Hence a systematic review of plant based probiotic products was conducted to identify the most suitable and acceptable plant foods medium for probiotic bacteria. For this, studies published and indexed in Google scholar between2002-2017 were manually searched and analyzed. The study includes substrates from different food groups and combinations: cereals (22%), pulses (3%), cereal-pulse mix (5%), vegetables (19%), fruits (32%), combination (16%) and unconventional foods (3%). Soymilk was found to be the most promising among pulse-based substrates. The shelf life and viability of probiotics varied from 7 days to 4 weeks based on the initial count, temperature, time, strain of bacteria and substrate. Though a majority of the studies were carried out with fruit substrates, good probiotic count, improvements in nutritional properties, better acceptability and quicker fermentation time was found incereal based products. Hence, it is concluded that cereal based products is more suitable for the production of non-dairy probiotic products.

The functional and organoleptic characterization of a dairy-free dessert containing a novel probiotic food ingredient

New eating habits and diversification of tastes in consumers have led to the scientific community and the food industry expanding the range of probiotic foods and novel probiotic ingredients.

Effect of Non-Dairy Food Matrices on the Survival of Probiotic Bacteria during Storage

The viability of probiotics in non-dairy food products during storage is required to meet content criteria for probiotic products. This study investigated whether non-dairy foods could be matrices for probiotics. Selected probiotic bacteria were coated on non-dairy foods under two storage conditions, and viabilities were assessed. The non-dairy foods were coated with 5-7 log cfu g-1 of Lactobacillus acidophilus ATCC4356T, Lactobacillus plantarum RC30, and Bifidobacterium longum ATCC15707T. The coated non-dairy foods were stored at 20 °C and 20% relative humidity (RH) or 30 °C and 50% RH. Viability of probiotic bacteria was determined after 0, 2, and 4 weeks of storage. B. longum showed the highest survival at week 4 of 6.5-6.7 log cfu g-1 on wheat bran and oat, compared with 3.7-3.9 log cfu g-1 of L. acidophilus and 4.2-4.8 log cfu g-1 of L. plantarum at 20 °C 20% RH. Under the storage conditions of 30 °C 50% RH, survival of 4.5 log cfu g-1 of B. longum was also found on oat and peanut. This was two and four times higher than the population of L. acidophilus and L. plantarum, respectively. The results suggest that probiotics can survive on non-dairy foods under ambient storage conditions. However, the storage conditions, food matrices, and probiotic strains should be carefully chosen to maximize probiotic bacteria survival.

Biochemical Engineering Approaches for Increasing Viability and Functionality of Probiotic Bacteria

The literature presents a growing body of evidence demonstrating the positive effect of probiotics on health. Probiotic consumption levels are rising quickly in the world despite the fluctuation of their viability and functionality. Technological methods aiming at improving probiotic characteristics are thus highly wanted. However, microbial metabolic engineering toolbox is not available for this kind of application. On the other hand, basic microbiology teaches us that bacteria are able to exhibit adaptation to external stresses. It is known that adequately applied sub-lethal stress, i.e., controlled in amplitude and frequency at a given stage of the culture, is able to enhance microbial robustness. This property could be potentially used to improve the viability of probiotic bacteria, but some technical challenges still need to be overcome before any industrial implementation. This review paper investigates the different technical tools that can be used in order to define the proper condition for improving viability of probiotic bacteria and their implementation at the industrial scale. Based on the example of Bifidobacterium bifidum, potentialities for simultaneously improving viability, but also functionality of probiotics will be described.

Potentially synbiotic fermented beverage with aqueous extracts of quinoa (Chenopodium quinoa Willd) and soy

The aim of this study was to develop a potentially synbiotic beverage fermented with Lactobacillus casei LC-1 based on aqueous extracts of soy and quinoa with added fructooligosaccharides (FOS). Five formulations with differing proportions of soy and quinoa extracts were tested. The viability of the microorganism, the pH, and the acidity of all formulations were monitored until the 28th day of storage at 5 ℃. The chemical composition of the extracts and beverages and the rheological and sensory properties of the final products were analyzed. Although an increase in acidity and a decrease in pH were observed during the 28 days of storage, the viability of the probiotic microorganism was maintained at 108 CFU·mL−1 in all formulated beverages throughout the storage period. An increase in viscosity and consistency in the formulations with higher concentrations of quinoa (F1 and F2) was observed. Formulation F4 (70% soy and 30% quinoa extracts) showed the least hysteresis. Formulations F4 and F5 (100% soy extract) had the best sensory acceptance while F4 resulted in the highest intention to purchase from a group of 80 volunteers. For chemical composition, F3 (50% soy and 50% quinoa extracts) and F4 showed the best results compared to similar fermented beverages. The formulation F4 was considered the best beverage overall.

Effect of the consumption of a new symbiotic shake on glycemia and cholesterol levels in elderly people with type 2 diabetes mellitus

BACKGROUND

The consumption of foods containing probiotic and prebiotic ingredients is growing consistently every year, and in view of the limited number of studies investigating their effect in the elderly.

OBJECTIVE

The objective of this study was to evaluate the effect of the consumption of a symbiotic shake containing Lactobacillus acidophilus, Bifidobacterium bifidum and fructooligosaccharides on glycemia and cholesterol levels in elderly people.

METHODS

A randomized, double-blind, placebo-controlled study was conducted on twenty volunteers (ten for placebo group and ten for symbiotic group), aged 50 to 60 years. The criteria for inclusion in the study were: total cholesterol > 200 mg/dL; triglycerides > 200 mg/dL and glycemia > 110 mg/dL. Over a total test period of 30 days, 10 individuals (the symbiotic group) consumed a daily dose of 200 mL of a symbiotic shake containing 10(8) UFC/mL Lactobacillus acidophilus, 10(8) UFC/mL Bifidobacterium bifidum and 2 g oligofructose, while 10 other volunteers (the placebo group) drank daily the same amount of a shake that did not contain any symbiotic bacteria. Blood samples were collected 15 days prior to the start of the experiment and at 10-day intervals after the beginning of the shake intake. The standard lipid profile (total cholesterol, triglycerides and HDL cholesterol) and glycemia, or blood sugar levels, were evaluated by an enzyme colorimetric assay.

RESULTS

The results of the symbiotic group showed a non-significant reduction (P > 0.05) in total cholesterol and triglycerides, a significant increase (P < 0.05) in HDL cholesterol and a significant reduction (P < 0.05) in fasting glycemia. No significant changes were observed in the placebo group.

CONCLUSION

The consumption of symbiotic shake resulted in a significant increase in HDL and a significant decrease of glycemia.