Identification of Lactobacillus strains from breast-fed infant and investigation of their cholesterol-reducing effects

A neurotherapeutic approach with Lacticaseibacillus rhamnosus E9 on gut microbiota and intestinal barrier in MPTP-induced mouse model of Parkinson's disease

The gut microbiota plays a crucial role in neural development and progression of neural disorders like Parkinson's disease (PD). Probiotics have been suggested to impact neurodegenerative diseases via gut-brain axis. This study aims to investigate the therapeutic potential of Lacticaseibacillus rhamnosus E9, a high exopolysaccharide producer, on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced mouse model of PD. C57BL/6 mice subjected to MPTP were fed L. rhamnosus E9 for fifteen days and sacrificed after the last administration. Motor functions were determined by open-field, catalepsy, and wire-hanging tests. The ileum and the brain tissues were collected for ELISA, qPCR, and immunohistochemistry analyses. The cecum content was obtained for microbiota analysis. E9 supplementation alleviated MPTP-induced motor dysfunctions accompanied by decreased levels of striatal TH and dopamine. E9 also reduced the level of ROS in the striatum and decreased the DAT expression while increasing the DR1. Furthermore, E9 improved intestinal integrity by enhancing ZO-1 and Occludin levels and reversed the dysbiosis of the gut microbiota induced by MPTP. In conclusion, E9 supplementation improved the MPTP-induced motor deficits and neural damage as well as intestinal barrier by modulating the gut microbiota in PD mice. These findings suggest that E9 supplementation holds therapeutic potential in managing PD through the gut-brain axis.

Isolation and Characterization of a Cholesterol-Lowering Bacteria from Bubalus bubalis Raw Milk

Probiotics retrieved from animal sources have substantial health benefits for both humans and animals. The present study was designed to identify lactic acid bacteria (LAB) isolated from domestic water buffalo milk (Bubalus bubalis) and to evaluate their potential as target-based probiotics. Forty-six LAB strains were isolated and, among them, five strains (NMCC-M2, NMCC-M4, NMCC-M5, NMCC-M6, and NMCC-M7) were regarded as possible probiotics on the basis of their phenotypic and biochemical properties. These isolates were molecularly identified as Weissella confusa (NMCC-M2), Leuconostoc pseudo-mesenteroides (NMCC-M4), Lactococcus lactis Subsp. hordniae (NMCC-M5), Enterococcus faecium NMCC-M6, and Enterococcus lactis NMCC-M7. The tested bacterial strains showed significant antimicrobial activity, susceptibility to antibiotics, acid and bile tolerance, sugar fermentation, enzymatic potential, and nonhemolytic characteristics. Interestingly, NMCC-M2 displayed the best probiotic features including survival at pH 3 and 0.5% (w/v) bile salts, complete susceptibility to the tested antibiotics, high enzymatic potential, and in vitro cholesterol reduction (48.0 µg/mL for NMCC-M2) with 0.3% bile salt supplementation. Therefore, the isolated strain NMCC-M2 could be considered as a potential target-based probiotic in cholesterol-lowering fermented food products.

Effects of Lactic Acid Bacteria Isolated from Equine on Salmonella-Infected Gut Mouse Model

The aim of this study was to evaluate the antibacterial potential of lactic acid bacteria (Weissella confuse, Pediococcus acidilactici, and Ligilactobacillus equi) isolated from healthy equine in Wuhan against Salmonella Typhimurium CVCC542-induced mice model on intestinal microflora. In previous studies, these isolated strains showed good probiotic potentials in vitro. In this study, fifty healthy mice were randomly divided into five groups, the blank control group, the control group, the Pediococcus acidilactici group (1 × 10⁸ CFU/day), the Ligilactobacillus equi group (1 × 10⁸ CFU/day), and the Weissella confuse group (1 × 10⁸ CFU/day). The body weight in control group and Weissella confuse group showed significant decreased (P < 0.05, P < 0.01), while Pediococcus acidilactici group and Ligilactobacillus equi group showed good recovering after treatments. The lowest diarrhea rate was shown in Ligilactobacillus equi group after treatment. In histopathology, Ligilactobacillus equi group showed the least structural damage in duodenum, and all probiotic treatment groups showed less damage in cecum. The sequence data and optical transform unit showed that Pediococcus acidilactici group and Ligilactobacillus equi group had higher number than control group, while the diversity data showed that the control group and Weissella confuse group had lower diversity in cecum. Microbial community analysis showed increased abundance of Firmicutes, Bacteroidetes, uncultured_bacterium_f_Muribaculaceae, and Lactobacillus in treatment groups, while potential microbes that can induce intestinal diseases such as Verrucomicrobia, Akkermansia, and Lachnospiraceae_NK4A136_group decreased in the treatment groups. In conclusion, lactic acid bacteria isolated from the healthy horses could alleviate the infection of Salmonella and regulate intestinal flora.

Influence of a cholesterol-lowering strain Lactobacillus plantarum LP3 isolated from traditional fermented yak milk on gut bacterial microbiota and metabolome of rats fed with a high-fat diet

L. plantarum LP3 isolated from traditinal fermented Tibetan yak milk has been identified as a potential probiotic candidate strain with high cholesterol-lowering activity. In this study, thirty Sprague-Dawley (SD) rats were randomly divided into three groups, including normal diet (NC), high-fat diet (HC), and high-fat diet + L. plantarum LP3 (HLp). The effects of L. plantarum LP3 on plasma lipid profile, gut bacterial microbiota, and metabolome induced by high-fat diet in rats were investigated. Results shown that L. plantarum LP3 administration was found to reduce the levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol (LDL-C) and atherogenic index in the serum of high-fat diet rats. It also controlled the decrease of Bacteroidetes and increase of Firmicutes at the phylum level in gut microbiota induced by high-fat diet in SD rats and increased the diversity and relative abundance of intestinal flora in obese rats. In particular, the LP3 strain controlled the changes induced by the high-fat diet in the abundance of for Lachnospiraceae and Erysipelotrichaceae. We also further observed the beneficial regulatory effects of L. plantarum LP3 on changes in the levels of obesity-related metabolites. The biosynthesis of fatty acids, steroids, and bile acids and metabolism of linoleic acid, linolenic acid, and arachidonic acid were the main metabolic pathways adjusted by L. plantarum LP3 in obese rats, and the metabolic rates were similar to those observed in normal diet rats levels. The findings of this study provided useful information on the mechanism underlying the hypocholesterolemic effects of L. plantarum LP3 in the high-fat induced SD rat model with the perspective of modulation of gut microbiota and metabolites.

Histamine and cholesterol lowering abilities of lactic acid bacteria isolated from artisanal Pico cheese

AIMS

This study was designed to select lactic acid bacteria with histamine- and cholesterol-reducing abilities to be used as potential probiotics.

METHODS AND RESULTS

Thirty strains of lactic acid bacteria isolated from an artisanal raw milk cheese were screened for their abilities to degrade histamine, reduce cholesterol and hydrolyse bile salts. Strains were also screened for safety and probiotic traits, such as resistance to gastrointestinal conditions, adhesion to Caco-2 cells, resistance to antibiotics and presence of virulence genes. Two Lactobacillus paracasei strains presented high cholesterol- and histamine-lowering abilities, tested negative for the presence of virulence genes and showed susceptibility to most important antibiotics. These strains were also shown to possess desirable in vitro probiotic properties, revealed by tolerance to gastrointestinal conditions and high adhesion to intestinal cells.

CONCLUSIONS

Among the screened strains, Lb. paracasei L3C21M6 revealed the best cholesterol and histamine reducing abilities together with desirable probiotic and safety features to be used in food applications.

SIGNIFICANCE AND IMPACT OF THE STUDY

The strain L3C21M6 is a good candidate for use as a probiotic with histamine-degrading activity and cholesterol lowering effect. In addition, this strain could be use in dairy foods to prevent histamine food poisoning.

The relationship between the structural characteristics of lactobacilli-EPS and its ability to induce apoptosis in colon cancer cells in vitro

Colon cancer is one of the most common cancer around the world. Exopolysaccharides (EPSs) produced by lactobacilli as potential prebiotics have been found to have an anti-tumor effect. In this study, lyophilized EPSs of four Lactobacillus spp. for their impact on apoptosis in colon cancer cells (HT-29) was evaluated using flow cytometry. The relationship between capability of a lactobacilli-EPS to induce apoptosis and their monosaccharide composition, molecular weight (MW), and linkage type was investigated by HPLC, SEC, and NMR, respectively. Changes in apoptotic-markers were examined by qPCR and Western Blotting. EPSs were capable of inhibiting proliferation in a time-dependent manner and induced apoptosis via increasing the expression of Bax, Caspase 3 and 9 while decreasing Bcl-2 and Survivin. All EPSs contained mannose, glucose, and N-acetylglucosamine with different relative proportions. Some contained arabinose or fructose. MW ranged from 102-104Da with two or three fractions. EPS of L. delbrueckii ssp. bulgaricus B3 having the highest amount of mannose and the lowest amount of glucose, showed the highest apoptosis induction. In conclusion, lactobacilli-EPSs inhibit cell proliferation in HT-29 via apoptosis. Results suggest that a relationship exists between the ability of EPS to induce apoptosis and its mannose and glucose composition.

Determining the probiotic potential of cholesterol-reducing Lactobacillus and Weissella strains isolated from gherkins (fermented cucumber) and south Indian fermented koozh

This study sought to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from traditionally fermented south Indian koozh and gherkin (cucumber). A total of 51 LAB strains were isolated, among which four were identified as Lactobacillus spp. and three as Weissella spp. The strains were screened for their probiotic potential. All isolated Lactobacillus and Weissella strains were capable of surviving under low pH and bile salt conditions. GI9 and FKI21 were able to survive at pH 2.0 and 0.50% bile salt for 3 h without losing their viability. All LAB strains exhibited inhibitory activity against tested pathogens and were able to deconjugate bile salt. Higher deconjugation was observed in the presence of sodium glycocholate (P < 0.05). Strain FKI21 showed maximum auto-aggregation (79%) and co-aggregation with Escherichia coli MTCC 1089 (68%). Exopolysaccharide production of LAB strains ranged from 68.39 to 127.12 mg/L (P < 0.05). Moreover, GI9 (58.08 μg/ml) and FKI21 (56.25 μg/ml) exhibited maximum cholesterol reduction with bile salts. 16S rRNA sequencing confirmed GI9 and FKI21 as Lactobacillus crispatus and Weissella koreensis, respectively. This is the first study to report isolation of W. koreensis FKI21 from fermented koozh and demonstrates its cholesterol-reducing potential.

Isolation of potential probiotic Lactobacillus oris HMI68 from mother's milk with cholesterol-reducing property

The objective of this study was to evaluate the probiotic properties of Lactobacillus strains isolated from mother's milk and their effects on cholesterol assimilation. In this study 120 isolates from mother's milk were phenotypically and genotypically characterized. Among these, only 6 predominant strains were identified as Lactobacillus spp. The following parameters were selected as important test variables in model stomach passage survival trials: acid and bile tolerance, antimicrobial activity, antibiotic susceptibility and cholesterol reduction. Results showed that the considerable variation existed among six strains. Moreover, the strain HMI68 is the most acid-tolerant and the HMI28 and HMI74 is the most acid-sensitive of all strains tested. HMI118 did not grow at 0.5% and 1% bile concentration after 5 h but the HMI68 and HMI43 showed some tolerance to such bile concentration. The differences found in the growth rate were not significant (P > 0.05). HMI68 showed resistance to most of the antibiotics as well as antagonistic activity against the tested pathogens. The amount of cholesterol reduction is increased when the media supplemented with bile salts. HMI68 assimilate 61.05 ± 0.05 μg/ml cholesterol with the presence of 0.3% bile salt this could be significantly decreased by 25.41 ± 1.09 μg/ml without bile salt. HMI68 was identified to be Lactobacillus oris HMI68 and 16S rRNA sequence was deposited in the National Center for Biotechnological Information (GenBank). For the first time the cholesterol-reducing property of L. oris isolated from mother's milk were investigated in this study. Therefore the effective L. oris HMI68 strain was regarded as a candidate probiotic.