Dose-Dependent Relationship between Protection of Thioacetamide-Induced Acute Liver Injury and Hyperammonemia and Concentration of Lactobacillus salivarius Li01 in Mice

This research investigated the relationship between the concentration of Lactobacillus salivarius Li01 and its impact on mice that had a thioacetamide-induced acute liver injury and hyperammonemia. These findings could provide new insights into the effective, proper, and safe use of probiotics.

In Vitro Antimicrobial Activity and Aggregation Abilities of Probiotic Lactobacillus casei and Lactobacillus salivarius Against Oral Pathogens

The antagonistic effect of probiotics against oral pathogens merits exploration because these bacteria are beneficial to the host’s health. The antimicrobial activity of two probiotic strains, Lactobacillus casei and Lactobacillus salivarius, as well as L. casei and L. salivarius combination (1:1), was investigated against Streptococcus mutans, Streptococcus sobrinus, Candida albicans, Candida glabrata and Candida tropicalis using agar-well diffusion, auto-aggregation and coaggregation assays. L. salivarius cell-free supernatant (CFS) alone exhibited greater inhibitory effect against Streptococci spp. compared to L. casei CFS alone and the combination. However, no inhibition was observed for Candida spp. L. salivarius alone exhibited significantly stronger auto-aggregation than L. casei alone (p ≤ 0.05) and L. casei and L. salivarius combination. L. salivarius exhibited strong coaggregation ability with Candida spp., followed by Streptococci spp. while L. casei exhibited coaggregation only with Streptococci spp. However, L. casei and L. salivarius combination did not display any coaggregation with all strains. L. salivarius alone exhibited a stronger antagonistic effect on the tested organisms than L. casei alone or in combination. Based on the results, both probiotic strains showed good antimicrobial activities against oral pathogens and should be further studied for their human health benefits.

Effect of inulin and oat flour on viability of probiotics and physicochemical properties of reduced fat synbiotic ice cream

PurposeThe purpose of this study is to investigate the viability of probiotics, physicochemical and sensory properties of reduced fat synbiotic ice cream.Design/methodology/approachThe treatments were as follows: control was made by the addition of Lactobacillus salivarius NBIMCC 1589 and Lactobacillus crispatus NBIMCC 2451 (1:1). The treatments (T1, T2 and T3) were made with the addition of L. salivarius NBIMCC 1589 and L. crispatus NBIMCC 2451 (1:1) + 2% oat flour, 2% inulin and 4% oat flour + inulin (1:1). Physiochemical parameters (pH, moisture, fat, protein, fibre, ash, overrun, first dripping time and melting rate) were determined.FindingsThe ice cream with inulin and oat flour had lower moisture content, which was recorded 70.41, 69.88 and 68.82% for T1, T2 and T3, respectively. While the protein, fat and ash content of treated samples increased. The highest acidity (0.43%) was recorded in T3. The overrun increased by around 43% in T3 compared with control. The viable counts of probiotics were significantly (p = 0.05) decreased by two or three log cycles. Finally, T3 received the highest sensory score, which could be due to the combination between oat flour and inulin.Originality/valueA novel ice cream was produced using a combination of inulin and oat flour, which enhanced the viability of added probiotics. Reduced fat synbiotic ice cream was a good carrier for probiotics, which facilitates the production of healthy dairy products.

Alterations of Suckling Piglet Jejunal Microbiota Due to Infection With Porcine Epidemic Diarrhea Virus and Protection Against Infection by Lactobacillus salivarius

The high mortality of neonatal piglets due to porcine epidemic diarrhea virus (PEDV) infection has caused huge economic losses to the pig industry. The intestinal microbiota is an important barrier against invaders entering the gastrointestinal route. In this study, we examined the differences between intestinal microbiota of PEDV-infected and healthy piglets. According to the viral copy numbers, 16 crossbred (Landrace-Yorkshire) piglets were divided into three groups: uninfected, low virus load, and high virus load groups. Next, 16S rRNA sequencing was performed to determine the microbiota composition in jejunal content and jejunal mucosal samples from the three groups. PEDV infection induced an imbalance in the microbiota of both jejunal content and jejunal mucosa. The abundance of phylum Firmicutes was higher in uninfected piglets than in infected piglets, whereas the abundance of Proteobacteria was lower in uninfected piglets. Principal coordinate analysis showed significant separation of jejunal microbiota between different groups. Linear discriminant analysis (LDA) effect size (LEfSe) identified Lactobacillus salivarius as a potential biomarker among three groups at the level of species. Then, in vitro, L. salivarius was able to suppress the infection of PEDV to IPEC-J2 cells and decreased the expression of GRP78 (Glucose-regulating protein 78). In addition, we detected the mRNA expression of genes involved in the FAK/PI3K/Akt signaling pathway. When IPEC-J2 cells were treated with L. salivarius before PEDV infection, the mRNA expression levels of ITGA1, ITGA5, ITGB5, FAK, PIK3R1, PIK3CA and AKT1 were significantly higher than those in the control cells (without treatment) at different times post-infection, indicating that L. salivarius may upregulate the FAK/PI3K/Akt signaling pathway in IPEC-J2 cells to resist PEDV infection. In summary, PEDV infection altered microbial communities in both jejunal content and jejunal mucosa. L. salivarius has a protective effect against PEDV infection in IPEC-J2 cells. This study provides a potentially effective strategy to prevent the occurrence and control the spread of PED in the pig production.

Comparative Genomic Analysis Determines the Functional Genes Related to Bile Salt Resistance in Lactobacillus salivarius

Lactobacillus salivarius has drawn attention because of its promising probiotic functions. Tolerance to the gastrointestinal tract condition is crucial for orally administrated probiotics to exert their functions. However, previous studies of L. salivarius have only focused on the bile salt resistance of particular strains, without uncovering the common molecular mechanisms of this species. Therefore, in this study, we expanded our research to 90 L. salivarius strains to explore their common functional genes for bile salt resistance. First, the survival rates of the 90 L. salivarius strains in 0.3% bile salt solutions were determined. Comparative genomics analysis was then performed to screen for the potential functional genes related to bile salt tolerance. Next, real-time polymerase chain reaction and gene knockout experiments were conducted to further verify the tolerance-related functional genes. The results indicated that the strain-dependent bile salt tolerance of L. salivarius was mainly associated with four peptidoglycan synthesis-related genes, seven phosphotransferase system-related genes, and one chaperone-encoding gene involved in the stress response. Among them, the GATase1-encoding gene showed the most significant association with bile salt tolerance. In addition, four genes related to DNA damage repair and substance transport were redundant in the strains with high bile salt tolerance. Besides, cluster analysis showed that bile salt hydrolases did not contribute to the bile salt tolerance of L. salivarius. In this study, we determined the global regulatory genes, including LSL_1568, LSL_1716 and LSL_1709, for bile salt tolerance in L. salivarius and provided a potential method for the rapid screening of bile salt-tolerant L. salivarius strains, based on PCR amplification of functional genes.

Antioxidants Bioaccessibility and Lactobacillus salivarius (CECT 4063) Survival Following the In Vitro Digestion of Vacuum Impregnated Apple Slices: Effect of the Drying Technique, the Addition of Trehalose, and High-Pressure Homogenization

To benefit the health of consumers, bioactive compounds must reach an adequate concentration at the end of the digestive process. This involves both an effective release from the food matrix where they are contained and a high resistance to exposure to gastrointestinal conditions. Accordingly, this study evaluates the impact of trehalose addition (10% w/w) and homogenization (100 MPa), together with the structural changes induced in vacuum impregnated apple slices (VI) by air-drying (AD) and freeze-drying (FD), on Lactobacillus salivarius spp. salivarius (CECT 4063) survival and the bioaccessibility of antioxidants during in vitro digestion. Vacuum impregnated apple slices conferred maximum protection to the lactobacillus strain during its passage through the gastrointestinal tract, whereas drying with air reduced the final content of the living cells to values below 10 cfu/g. The bioaccessibility of antioxidants also reached the highest values in the VI samples, in which the release of both the total phenols and total flavonoids to the liquid phase increased with in vitro digestion. The addition of trehalose and homogenization at 100 MPa increased the total bioaccessibility of antioxidants in FD and AD apples and the total bioaccessibility of flavonoids in the VI samples. Homogenizing at 100 MPa also increased the survival of L. salivarius during in vitro digestion in FD samples.

Anti-salmonella potential and antioxidant activity of fermented fruit-based juice by lactic acid bacteria and its biotransformation

Background: Lactic acid bacteria-based fermentation clearly contributes to improving nutritional value and exhibits various health benefits. The demand for non-dairy functional beverages, such as fruit beverages, as an alternative vehicle for probiotics is increasing because of lifestyle choices or health conditions. Therefore, the objective of this study was to evaluate the anti-Salmonella potential and antioxidant activity of fermented fruit-based juice by lactic acid bacteria and its biotransformation. Methods: In this study, to produce the fermented fruit-based juice (FFJ), the mixed fruit juice (MFJ) was fermented by Lactobacillus plantarum TISTR 1465 and Lactobacillus salivarius TIST 1112 for 72 hrs. The potential function, anti-Salmonella by the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiofilm activities of FFJ against Salmonella Typhi DMST 22842 was evaluated. The antioxidative capacity was determined by DPPH and FRAP assay. The active volatile compounds were identified by GC-MS. Results: A novel functional FFJ showed excellent growth capacity with 8 log CFU/mL of probiotics Lactobacillus plantarum TISTR 1465 and Lactobacillus salivarius TIST 1112. MIC and MBC values in the FFJ were 500 mg/mL after 72 hrs of fermentation. After 48hrs of fermentation, biofilm formation inhibition was significant (p < 0.05) with 95.27% ± 2.26% inhibition; biofilm metabolic activity inhibition was also significant (p < 0.05) with 89.25% ± 0.18% inhibition. The volatile compounds present in the FFJ were fruity flavors and aromas, most of have antimicrobial and antioxidant properties. These compounds comprise various classes, including alcohols, organic acid, ester, and ketone. In both LAB fermentations, the most abundant volatile alcohol was isoamyl alcohol, followed by 1-hexanol and 2,3-Butanolone; acetic acid was only present in L. plantarum fermentation. In addition, DPPH radical scavenging and FRAP assay showed the mixed fruit juice had dramatically increased antioxidant activity after 48 hrs of fermentation.Conclusion: The findings of this work indicate that the obtained fermented fruit-based juice (FFJ) showed excellent growth capacity of probiotics, Lactobacillus plantarum TISTR 1465 and Lactobacillus salivarius TIST 1112, and produced the volatile compounds from biotransformation. This not only improved fruit flavor and aroma, but also influenced antibacterial activity against the pathogen Salmonella Typhi DMST 22842, as well as increased antioxidant activity. Therefore, the FFJ could be a novel functional fermented drink for vegan and non-diary consumption.Keywords: Lactic acid bacteria, Probiotics, Biotransformation, Non-dairy functional beverage, Anti-Salmonella