Study on intestinal survival and cholesterol metabolism of probiotics

Characterization of a symbiotic beverage based on water-soluble soybean extract fermented by Lactiplantibacillus plantarum ATCC 8014

The health benefits of functional foods are associated with consumer interest and have supported the growth of the market for these types of foods, with emphasis on the development of new formulations based on plant extracts. Therefore, the present study aimed to characterize a symbiotic preparation based on water-soluble soy extract, supplemented with inulin and xylitol and fermented by Lactiplantibacillus plantarum ATCC 8014. Regarding nutritional issues, the symbiotic formulation can be considered a source of fiber (2 g/100 mL) and proteins (2.6 g/100 mL), and it also has a low-fat content and low caloric value. This formulation, in terms of microbiological aspects, remained adequate to legal standards after storage for 60 days under refrigeration and also presented an adequate quantity of the aforementioned probiotic strain, corresponding to 9.11 Log CFU.mL-1. These viable L. plantarum cells proved to be resistant to simulated human gastrointestinal tract conditions, reaching the intestine at high cell concentrations of 7.95 Log CFU.mL-1 after 60 days of refrigeration. Regarding sensory evaluation, the formulation showed good acceptance, presenting an average overall impression score of 6.98, 5.98, and 5.16, for control samples stored for 30 and 60 days under refrigeration, respectively. These results demonstrate that water-soluble soy extract is a suitable matrix for fermentation involving L. plantarum ATCC 8014, supporting and providing data on the first steps towards the development of a symbiotic functional food, targeting consumers who have restrictions regarding the consumption of products of animal origin, diabetics, and individuals under calorie restrictions.

Bifidobacterium animalis subsp. lactis F1-7 Alleviates Lipid Accumulation in Atherosclerotic Mice via Modulating Bile Acid Metabolites to Downregulate Intestinal FXR

The dysfunction of intestinal microbiota and bile acid metabolism is related to the pathogenesis of atherosclerosis. This study we explored the mechanism of Bifidobacterium animalis subsp. lactis F1-7 (Bif. animalis F1-7), improving atherosclerosis by regulating the bile acid metabolism and intestinal microbiota in the ApoE-/- mice. The Bif. animalis F1-7 effectively reduced aortic plaque accumulation and improved the serum and liver lipid levels in atherosclerotic mice. The untargeted metabolomics revealed that Bif. animalis F1-7 reduced the glycine-conjugated bile acids and the levels of differential metabolite lithocholic acid (LCA) significantly. Downregulation of LCA decreased the intestinal levels of the farnesoid X-activated receptor (FXR) and regulated the bile acid metabolism through the FXR/FGF15/CYP7A1 pathway. Furthermore, the 16srRNA gene sequencing analysis revealed that structural changes in intestinal microbiota with an increase in the abundance of Bifidobacterium, Lactobacillus, Faecalibaculum, Desulfovibrio, and a decrease in Dubosiella, Clostridium_sensu_stricto_1, and Turicibacter following the Bif. animalis F1-7 intervention. Correlation analysis showed that the changes in intestinal microbiota mentioned above were significantly correlated with bile acid metabolism in atherosclerotic mice. In conclusion, this study sheds light on the mechanisms by which Bif. animalis F1-7 regulates atherosclerosis.

Safety assessment, whole genome sequence, and metabolome analysis of Streptococcus thermophilus CICC 20372 for bone cement fermentation

Bone is a kind of meat processing by-product with high nutritional value but low in calorie, which is a typical food in China and parts of East Asian countries. Microbial fermentation by lactic acid bacteria showed remarkable advantages to increase the absorption of nutrients from bone cement by human body. Streptococcus thermophilus CICC 20372 is proven to be a good starter for bone cement fermentation. No genes encoding virulence traits or virulence factors were found in the genome of S. thermophilus CICC 20372 by a thorough genomic analysis. Its notable absence of antibiotic resistance further solidifies the safety. Furthermore, the genomic analysis identified four types of gene clusters responsible for the synthesis of antimicrobial metabolites. A comparative metabolomic analysis was performed by cultivating the strain in bone cement at 37 °C for 72 h, with the culture in de Man, Rogosa, and Sharpe (MRS) medium as control. Metabolome analysis results highlighted the upregulation of pathways involved in 2-oxocarboxylic acid metabolism, ATP-binding cassette (ABC) transporters, amino acid synthesis, and nucleotide metabolism during bone cement fermentation. S. thermophilus CICC 20372 produces several metabolites with health-promoting function during bone cement fermentation, including indole-3-lactic acid, which is demonstrated ameliorative effects on intestinal inflammation, tumor growth, and gut dysbiosis. In addition, lots of nucleotide and organic acids were accumulated at higher levels, which enriched the fermented bone cement with a variety of nutrients. Collectively, these features endow S. thermophilus CICC 20372 a great potential strain for bone food processing.

Genomic and phenotypic-based safety assessment and probiotic properties of Streptococcus thermophilus FUA329, a urolithin A-producing bacterium of human milk origin

Streptococcus thermophilus FUA329, a urolithin A-producing bacterium, is isolated from human breast milk. The complete genome sequence of FUA329 did not contain any plasmids and at least 20 proteins were related to extreme environment resistance. Phenotypic assay results demonstrated that FUA329 was susceptible to 12 kinds of antibiotics and did not exhibit any hemolytic or nitrate reductase activity. Three free radical scavenging assays revealed that FUA329 have high antioxidant capability. FUA329 exhibited a cell surface hydrophobicity of 52.58 ± 1.17% and an auto-aggregation rate of 18.69 ± 2.48%. Moreover, FUA329 demonstrated a survival rate of over 60% in strong acid and bile salt environments, indicating that FUA329 may be stable colonization in the gastrointestinal tract. Additionally, we firstly found 3 potential proteins and 11 potential genes of transforming ellagic acid to urolithins in FUA329 genome. The above results indicate that FUA329 has credible safety and probiotic properties, as well as the potential to be developed as a new generation of urolithin A-producing probiotics.

Alleviation Syndrome of High-Cholesterol-Diet-Induced Hypercholesterolemia in Mice by Intervention with Lactiplantibacillus plantarum WLPL21 via Regulation of Cholesterol Metabolism and Transportation as Well as Gut Microbiota

Probiotics are prospective for the prevention and treatment of cardiovascular diseases. Until now, systematic studies on the amelioration of hypercholesterolemia have been rare in terms of (cholesterol metabolism and transportation, reshaping of gut microbiota, as well as yielding SCFAs) intervention with lactic acid bacteria (LAB). In this study, strains of Lactiplantibacillus plantarum, WLPL21, WLPL72, and ZDY04, from fermented food and two combinations (Enterococcus faecium WEFA23 with L. plantarum WLPL21 and WLPL72) were compared for their effect on hypercholesterolemia. Comprehensively, with regard to the above aspects, L. plantarum WLPL21 showed the best mitigatory effect among all groups, which was revealed by decreasing total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels, upregulated cholesterol metabolism (Cyp27a1, Cyp7b1, Cyp7a1, and Cyp8b1) levels in the liver, cholesterol transportation (Abca1, Abcg5, and Abcg8) in the ileum or liver, and downregulated Npc1l1. Moreover, it reshaped the constitution of gut microbiota; specifically, the ratio of Firmicutes to Bacteroidetes (F/B) was downregulated; the relative abundance of Allobaculum, Blautia, and Lactobacillus was upregulated by 7.48-14.82-fold; and that of Lachnoclostridium and Desulfovibrio was then downregulated by 69.95% and 60.66%, respectively. In conclusion, L. plantarum WLPL21 improved cholesterol metabolism and transportation, as well as the abundance of gut microbiota, for alleviating high-cholesterol-diet-induced hypercholesterolemia.

A new isolate of Streptomyces lateritius (Z1-26) with antibacterial activity against fish pathogens and immune enhancement effects on crucian carp (Carassius auratus)

The Streptomyces lateritius Z1-26 was isolated from soil samples which showed broad-spectrum antibacterial activity against a broad range of fish pathogens. The In Vivo Imaging System (IVIS) monitored that strain Z1-26 could survive and colonize in the gills and abdomen of crucian carp. The effects of dietary supplementation with strain Z1-26 were evaluated with respect to the growth performance, antioxidant capacity, and immune response of crucian carp. The results showed that the Z1-26-fed fish had a significantly higher growth rate than the fish fed the control diet. The immune and antioxidant parameters revealed that the non-specific immune indicators (AKP, SOD, and LZM) of the serum, the expression of immune-related genes (IgM, C3, and LZM), and antioxidant-related genes (Nrf2 and Keap1) of the immune organs were significantly increased, whereas the expression of pro-inflammatory factors (IL-1β, IL-8, and TNF-α) of the immune organs was significantly down-regulated in crucian carp fed strain Z1-26 compared with fish fed a control diet. Moreover, fish fed with Z1-26 supplemented diets showed a significantly improved survival rate after Aeromonas hydrophila infection. In addition, the whole genome analysis showed that strain Z1-26 possesses 28 gene clusters, including 6 polyketide synthetase (PKS), 4 non-ribosomal peptide-synthetase (NRPS), 1 bacteriocin, and 1 lantipeptide. In summary, these results indicated that strain Z1-26 could improve the growth performance and disease resistance in crucian carp, and has the potential to be developed as a candidate probiotics for the control of bacterial diseases in aquaculture.

The intestinal microbiome associated with lipid metabolism and obesity in humans and animals

Intestinal microbiota is considered to play an integral role in maintaining health of host by modulating several physiological functions including nutrition, metabolism and immunity. Accumulated data from human and animal studies indicate that intestinal microbes can affect lipid metabolism in host through various direct and indirect biological mechanisms. These mechanisms include the production of various signalling molecules by the intestinal microbiome, which exert a strong effect on lipid metabolism, bile secretion in the liver, reverse transport of cholesterol and energy expenditure and insulin sensitivity in peripheral tissues. This review discusses the findings of recent studies suggesting an emerging role of intestinal microbiota and its metabolites in regulating lipid metabolism and the association of intestinal microbiota with obesity. Additionally, we discuss the controversies and challenges in this research area. However, intestinal micro-organisms are also affected by some external factors, which in turn influence the regulation of microbial lipid metabolism. Therefore, we also discuss the effects of probiotics, prebiotics, diet structure, exercise and other factors on intestinal microbiological changes and lipid metabolism regulation.

Screening and Probiotic Potential Evaluation of Bacteriocin-Producing Lactiplantibacillus plantarum In Vitro

Probiotics are gaining attention due to their functions of regulating the intestinal barrier and promoting human health. The production of bacteriocins is one of the important factors for probiotics to exert beneficial properties. This study aimed to screen bacteriocin-producing Lactiplantibacillus plantarum and evaluate the probiotic potential in vitro. It was found that L. plantarum Q7, L. plantarum F3-2 and L. plantarum YRL45 could produce bacteriocins and inhibit common intestinal pathogens. These three strains had probiotic potential with tolerance to the gastrointestinal environmental and colonization in the gut, and exhibited various degrees of anti-inflammatory activity and tight junction function in the intestinal barrier. Particularly, L. plantarum YRL45 could significantly (p < 0.05) reduce the increase in nitric oxide (NO), prostaglandin E2 (PGE2), necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) induced by lipopolysaccharide (LPS), thereby easing inflammatory response. L. plantarum F3-2 could remarkably (p < 0.05) up-regulate the expression levels of ZO-1, Occludin and Claudin-1 in intestinal epithelial injured cells, which was conducive to protecting the intestinal barrier. These findings provided fundamental information about the probiotic properties of bacteriocin-producing L. plantarum, which suggested that L. plantarum Q7, L. plantarum F3-2 and L. plantarum YRL45 had the potential to be used as novel probiotic strains.

Krill Oil Combined with Bifidobacterium animalis subsp. lactis F1-7 Alleviates the Atherosclerosis of ApoE-/- Mice

There has been an increasing number of studies on the interaction between active substances and probiotics to improve disease. Both krill oil (KO) and probiotics have the effect of improving atherosclerotic cardiovascular disease, but the combined effect has not been explored. Therefore, the purpose of this study was to explore the improvement effect of KO combined with probiotics on atherosclerosis. The atherosclerotic plaque area of ApoE^−/− mice was detected after the intervention of KO, Bifidobacterium animalis subsp. lactis F1-7 (Bif. animalis F1-7), and KO combined with Bif. animalis F1-7. The results showed that Bif. animalis F1-7, KO, and KO combined with Bif. animalis F1-7 could significantly reduce the area of atherosclerotic plaque and improve the levels of serum lipids and inflammatory factors. They could regulate the farnesoid X receptor (FXR)/cholesterol 7-alpha hydroxylase (CYP7A1) pathway to reduce lipid accumulation. The intervention groups could also improve the inflammatory response by downregulating the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) pathway. The anti-inflammatory effect of the interaction group was significantly better than that of KO. It proved that Bif. animalis F1-7 might play a synergistic effect in the improvement of inflammation by KO to the alleviation of atherosclerosis.

Potential probiotics Lactobacillus casei K11 combined with plant extracts reduce markers of type 2 diabetes mellitus in mice

AIMS

Probiotics and plant extracts have been used to prevent the development of type 2 diabetes mellitus (T2DM). The study aimed to explore the effect of the interaction between potential probiotics and bitter gourd extract (BGE) or mulberry leaf extract (MLE) on T2DM.

METHODS AND RESULTS

Potential probiotics were tested for their gastrointestinal tract viability and growth situation combined with BGE and MLE in vitro. The diabetes model was constructed in C57BL/6 mice, and the potential effect and mechanism of regulating blood glucose were verified. Hematoxylin-eosin staining (HE), gas chromatography (GC), ELISA, and RT-PCR were also used for analysis. The results showed that Lactobacillus casei K11 had outstanding gastrointestinal tract viability and growth situation with plant extracts. Administration of L. casei K11 combined with BGE and MLE significantly reduced blood glucose levels and ameliorated insulin resistance in diabetic mice than the administration of Lactobacillus paracasei J5 combined with BGE and MLE. Moreover, in L. casei K11 combined with BGE and MLE groups, lipid metabolism, oxidative stress, and proinflammatory cytokine levels were regulated. Furthermore, the results indicated that L. casei K11 combined with BGE and MLE improved free fatty acid receptor 2 (FFAR2) upregulation, glucagon-like peptide-1 (GLP-1) secretion, and short-chain fatty acid (SCFA) levels.

CONCLUSIONS

These findings showed that L. casei K11 combined with BGE and MLE modified the SCFA-FFAR2-GLP-1 pathway to improve T2DM.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study identified a new modality for evaluating interactions between potential probiotics and plant extracts. Our findings revealed that L. casei K11 combined with BGE and MLE significantly promoted the SCFA-FFAR2-GLP-1 pathway to inhibit T2DM.

Diverse conditions contribute to the cholesterol-lowering ability of different Lactobacillus plantarum strains

It has been reported that Lactobacillus can remove cholesterol and thus might play an important role in lowering cholesterol in humans, but the underlying mechanism is still controversial. To confirm whether different strains have different cholesterol-lowering mechanisms, we explored the cholesterol-lowering abilities of different Lactobacillus plantarum strains, and the factors influencing their abilities. We found that all nine strains reduced the cholesterol concentration to some extent, but there were significant differences among them. In MRS broth, L. plantarum AR113 and AR171 showed the greatest cholesterol-lowering abilities of 27.89% and 19.90%, respectively, but AR501 and AR300 only showed reductions of 0.34% and 0.91%, respectively. Upon addition of 0.1% ox bile, the cholesterol-removal capability of most strains increased. L. plantarum AR511 showed the highest cholesterol removal rate, which increased from 5.8% to 37.14%, i.e., by a factor of approximately 6.4, but there was no significant change in the cholesterol removal rate of AR171. These results suggested that the effect of ox bile on the cholesterol-lowering ability was strain-specific. Except for the strains AR171, AR237 and AR495, the cholesterol-removal ability of the remaining six strains was positively correlated with the amount of free bile acid released. The addition of a bile salt hydrolase inhibitor had some effect on the cholesterol-removal ability of the six strains of bacteria other than AR171, AR237 and AR495, but little influence on the latter three. The effect of BSH was strain-specific. Similarly, the effect of pH was also strain-specific. Taken together, these results suggest that different strains of L. plantarum have different cholesterol-lowering capacities and different influencing factors. Therefore, further research is needed to explore the exact mechanism by which different strains lower cholesterol.

Weissella: An Emerging Bacterium with Promising Health Benefits

Weissella strains have been the subject of much research over the last 5 years because of the genus' technological and probiotic potential. Certain strains have attracted the attention of the pharmaceutical, medical, and food industries because of their ability to produce antimicrobial exopolysaccharides (EPSs). Moreover, Weissella strains are able to keep foodborne pathogens in check because of the bacteriocins, hydrogen peroxide, and organic acids they can produce; all listed have recognized pathogen inhibitory activities. The Weissella genus has also shown potential for treating atopic dermatitis and certain cancers. W. cibaria, W. confusa, and W. paramesenteroides are particularly of note because of their probiotic potential (fermentation of prebiotic fibers) and their ability to survive in the gastrointestinal tract. It is important to note that most of the Weissella strains with these health-promoting properties have been shown to be save safe, due to the absence or the low occurrence of virulence or antibiotic-resistant genes. A large number of scientific studies continue to report on and to support the use of Weissella strains in the food and pharmaceutical industries. This review provides an overview of these studies and draws conclusions for future uses of this rich and previously unexplored genus.

Anti-obesity effect of Lactobacillus plantarum CQPC01 by modulating lipid metabolism in high-fat diet-induced C57BL/6 mice

Lactic acid bacteria (LAB) are an important group of microorganisms in the food industry. LAB with health benefits are considered natural elements promoting consumer health. The study investigated the anti-obesity effects of Lactobacillus plantarum CQPC01 (LP-CQPC01) on high-fat diet-induced mice. Liver morphology, liver function indexes, lipid indexes, and inflammatory factors in the serum and liver were determined. Expressions of lipid metabolism-related gene were also detected by qPCR. LP-CQPC01 slowed the HFD-induced increase in body weight, decreased the organ indexes, alleviated hepatic lipid accumulation, and inhibited the increased adipose cell volume. LP-CQPC01 decreased lipid levels of serum and liver, and the contents of pro-inflammatory factors, and increased the IL-4 and IL-10 contents. LP-CQPC01 downregulated the expressions of the C/EBP-α and PPARγ mRNA and upregulated CYP7A1, CPT1, LPL, CAT, SOD1, and SOD2 mRNA. Our results indicated that LP-CQPC01 is a potential probiotic for preventing or alleviating high-energy intake-related lipid conditions. PRACTICAL APPLICATIONS: Obesity is a factor of a variety of cardiovascular diseases. Therefore, it is necessary to suppress the occurrence of fat accumulation in time. This study investigated the effect of LP-CQPC01 on lipid regulation in mice fed a high-fat diet (HFD) and clarified the mechanism of strain to alleviate obesity by enhancing the decomposition of cholesterol and detoxification of fat. LP-CQPC01 reduced fat accumulation without oxidative damage, and was confirmed by the attenuated pathological changes of liver. This research can serve as a significant reference for future research, prevention, and treatment of high-energy intake-related lipid conditions, and the development of functional foods with anti-obesity activity.

Regulating effect of Lactobacillus plantarum CQPC03 on lipid metabolism in high-fat diet-induced obesity in mice

Probiotics are regard as safety approaches for preventing and treating some chronic diseases. This study investigated the regulating effect of Lactobacillus plantarum CQPC03 (LP-CQPC03) on lipid metabolism in high-fat diet (HFD)-induced obesity in mice. The results showed that administration of LP-CQPC03 at a concentration of 1.0 × 10⁹  CFU/kg body weight inhibits HFD-induced obesity and improves lipid metabolism in the liver and serum. LP-CQPC03 intervention attenuated obesity-induced hepatic tissue damage, led decreases in hepatic triglyceride (42.02 mmol/gprot), total cholesterol (3.85 mmol/gprot), and LDL-C (1.03 mmol/gprot), and an increase in HDL-C (1.07 mmol/gprot). The same tendencies were observed in serum of HFD-fed mice. LP-CQPC03 intervention led a decrease in serum levels of aspartic transaminase, alanine transaminase, and alkaline phosphatase. LP-CQPC03 alleviated inflammation by increasing the level of interleukin (IL)-4 and IL-10, and decreasing the levels of pro-inflammatory factors, including IL-6, IL-1β, tumor necrosis factor-α, and interferon-γ. LP-CQPC03 also increased activities of SOD and GSH-Px in liver significantly and dropped the hepatic malondialdehyde (MDA) level from 3.39 nmol/gprot to 1.90 nmol/gprot. RT-qPCR results showed that the lipid metabolism-improving effect of LP-CQPC03 was performed by upregulating the expression of carnitine palmitoyltransferase 1, lipoprotein lipase, catalase, and superoxide dismutase 1. This study indicates that L. plantarum CQPC03 might be a potential probiotic that can help mitigate the adverse effects of excessive lipids on the liver, and prevent or alleviate high-energy intake-related obesity. PRACTICAL APPLICATIONS: Intaking high-energy foods is a potential risk of lipid metabolic disorder. Therefore, it is necessary to seek an effective and safe approach for preventing the obesity-related disease. This study found that LP-CQPC03 limited the rate of increase in body weight of mice fed on HFD, maintained normal hepatic tissue morphology, and exhibited a strong regulating effect on lipid metabolism. And the threshold concentration of LP-CQPC03 for the lipid-lowering effect was 1.0 × 10⁹  CFU/kg body weight. Therefore, LP-CQPC03 is a potential probiotic for preventing or alleviating high-energy intake-related obesity.

Probiotic characterization of Pediococcus strains isolated from Iranian cereal-dairy fermented product: Interaction with pathogenic bacteria and the enteric cell line Caco-2

In present study, we investigated the probiotic potential of three Pediococcus spp. isolated from Iranian traditional fermented cereal-dairy product, Tarkhineh. These 3 strains were identified as Pediococcus acidilactici VKU2, P. acidilactici IAH-5 and P. pentosaceus DHR005 by 16S rRNA gene sequencing. All the strain were found tolerate to pH 3 and 0.3% oxall for 3 h as well as simulated gastric and intestinal juice. P. acidilactici IAH-5 showed the highest cholesterol removal (67.52%), hydroxyl radical scavenging activity (58.32%), hydrophobicity (40.3%) and auto-aggregation (48%). Pediococcus spp. inhibited the growth of tested pathogens (Escherichia coli ATCC 25922, Pseudomonas aeruginosa PTCC 1707, Salmonella typhimurium PTCC 1609, and Staphylococcus aureus ATCC 25923) which the most susceptible strain was S. aureus. In competition assay, P. acidilactici IAH-5 was able to inhibited adhesion of 67.3% of S. typhimurium and in inhibition assay 45.8% of the pathogenic adhesion to Caco-2 cells were decreased. P. acidilactici VKU2 and P. acidilactici IAH-5 showed 16.32 and 12.25% adhesion to simulated epithelial cell line which were also confirmed by scanning electron microscopy. Pediococcus spp. did not showed DNase production or hemolytic activity which confirm its safety aspects. Our findings suggested that the P. acidilactici IAH-5 has the best properties with probiotic features and cholesterol assimilation for its application as novel bio-therapeutic and bio-preservation agents.