Selection of potential probiotic lactobacilli for cholesterol-lowering properties and their effect on cholesterol metabolism in rats fed a high-lipid diet

Antihyperlipidaemic effect of microencapsulated Lactobacillus plantarum LIP-1 on hyperlipidaemic rats

BACKGROUND

Previous studies have shown that Lactobacillus plantarum LIP-1 (hereafter LIP-1) has an obvious hypolipidemic effect, and microencapsulated probiotics can ensure the strains live through the gastrointestinal tract. Although there has been much research on both preparation and assessment methods for probiotics microcapsules, most assessments were made in vitro and few were validated in vivo. In this study, the protective effect of microencapsulation and the possible hypolipidemic mechanisms of probiotic LIP-1 were evaluated in rats. Treatments included rats fed on a normal diet, a high-fat diet, and a high-fat diet with an intragastric supplement of either non-microencapsulated LIP-1 cells (NME LIP-1) or microencapsulated LIP-1 (ME LIP-1). Lipid metabolism indicators were measured during the experiment and following euthanasia.

RESULTS

Microencapsulation increased survival and colonization of LIP-1 in the colon. ME LIP-1 was superior to NME LIP-1 in reducing cholesterol. The mechanisms behind the hypolipidemic effect exerted by LIP-1 are possibly due to promoting the excretion of cholesterol, improving antioxygenic potentials, enhancing recovery from the injury in the liver, cardiovascular intima and intestinal mucosa, promoting the generation of short-chain fatty acids, and improving lipid metabolism.

CONCLUSIONS

This study confirms that microencapsulation provides effective protection of LIP-1 in the digestive system and the role of LIP-1 in the prevention and cure of hyperlipidaemia, providing theoretical support for probiotics to enter clinical applications. © 2019 Society of Chemical Industry.

Probiotic Mixture of Lactobacillus plantarum Strains Improves Lipid Metabolism and Gut Microbiota Structure in High Fat Diet-Fed Mice

The global prevalence of obesity is rising year by year, which has become a public health problem worldwide. In recent years, animal studies and clinical studies have shown that some lactic acid bacteria possess an anti-obesity effect. In our previous study, mixed lactobacilli (Lactobacillus plantarum KLDS1.0344 and Lactobacillus plantarum KLDS1.0386) exhibited anti-obesity effects in vivo by significantly reducing body weight gain, Lee's index and body fat rate; however, its underlying mechanisms of action remain unclear. Therefore, the present study aims to explore the possible mechanisms for the inhibitory effect of mixed lactobacilli on obesity. C57BL/6J mice were randomly divided into three groups including control group (Control), high fat diet group (HFD) and mixed lactobacilli group (MX), and fed daily for eight consecutive weeks. The results showed that mixed lactobacilli supplementation significantly improved blood lipid levels and liver function, and alleviated liver oxidative stress. Moreover, the mixed lactobacilli supplementation significantly inhibited lipid accumulation in the liver and regulated lipid metabolism in epididymal fat pads. Notably, the mixed lactobacilli treatment modulated the gut microbiota, resulting in a significant increase in acetic acid and butyric acid. Additionally, Spearman's correlation analysis found that several specific genera were significantly correlated with obesity-related indicators. These results indicated that the mixed lactobacilli supplementation could manipulate the gut microbiota and its metabolites (acetic acid and butyric acid), resulting in reduced liver lipid accumulation and improved lipid metabolism of adipose tissue, which inhibited obesity.

Comparison of backslopping and two-stage fermentation methods for koumiss powder production based on chemical composition and nutritional properties

BACKGROUND

Koumiss is a traditional fermented beverage made from mare's milk. The traditional backslopping method for koumiss production has shortcomings in terms of microbiological diversity and nutritional characteristics. In this study, a two-stage fermentation method was established to scale up the production of koumiss powder. The chemical composition and nutritional properties of a novel two-stage fermentation koumiss powder (TKP) were compared with backslopping koumiss powder (BKP).

RESULTS

The TKP exhibited important nutritional and functional properties, including a high percentage of essential amino acids, and high polyunsaturated fatty acid, vitamin, and mineral content. The essential amino acid content of TKP was not significantly different from that of BKP. The oleic acid, linoleic acid, linolenic acid, and water-soluble vitamin content of TKP was higher than that of BKP. The Ca:P ratio of TKP was also close to the optimal Ca:P ratio in humans.

CONCLUSION

The novel method could be applied for the scaled-up production of koumiss powder with similar nutritional properties to traditional backslopping koumiss powder. The successful production of koumiss powder could also promote the development of the koumiss industry. © 2019 Society of Chemical Industry.

Can tailored nanoceria act as a prebiotic? Report on improved lipid profile and gut microbiota in obese mice

BACKGROUND

Microbiome modulation is a pillar intervention to treat metabolic syndrome, prestages, and cascade of related pathologies such as atherosclerosis, among others. Lactobacillus and Bifidobacterium probiotic strains demonstrate efficacy to reduce obesity, dyslipidemia, and improve metabolic health. Novel prebiotic substances composed with known probiotics may strongly synergize health benefits to the host. The aim of this study was to evaluate beneficial effects of Lactobacillus and Bifidobacterium strains (probiotics) if composed with nanoceria (potential prebiotic) to reduce cholesterol levels and restore gut microbiota in obese mice.

MATERIALS AND METHODS

Two lines of mice were used in the study: BALB/c mice (6-8 weeks, 18-24 g) and CBA mice (11-12 months, 20-26 g); experimental animals were fed by fat-enriched diet 3 weeks before the evaluation. Animals were divided into groups to test probiotic strains and nanoceria. All groups received probiotic strains orally and cerium dioxide orally or intravenously in various composition. A group of untreated animals was used as a control. Cholesterol level and gut microbiota of mice were studied.

RESULTS

Cerium dioxide nanoparticles, probiotic strain L. casei ІМV В-7280, and composition B. animalis VKB/B. animalis VKL applied separately and in different combinations all reduced at different levels free and bound cholesterol in blood serum of mice fed by fat-enriched diet. The combination of 0.01 M nanoceria and probiotic strain L. casei ІМV В-7280 resulted in the fastest cholesterol level decrease in both young and mature animals. Oral administration of CeO2 applied alone reduced the number of microscopic fungi in the gut of mice and Gram-positive cocci (staphylococci and/or streptococci). Application of L. casei IMV B-7280 as a probiotic strain increased most significantly the number of lactobacilli and bifidobacteria in the gut of mice. The most significant normalization of gut microbiota was observed after oral administration of alternatively either L. casei IMV B-7280 + 0.1 M CeO2 or L. casei IMV B-7280 + 0.01 M CeO2.

CONCLUSION

Dietary application of nanoceria combined with probiotic strains L. casei IMV B-7280, B. animalis VKB, and B. animals VKL has significantly reduced both free and bound cholesterol levels in serum. Simultaneous administration of probiotics and cerium nanoparticles as a prebiotic, in various combinations, significantly enhanced positive individual effects of them on the gut microbiota spectrum. The presented results provide novel insights into mechanisms behind nutritional supplements and open new perspectives for application of probiotics combined with substances demonstrating prebiotic qualities benefiting, therefore, the host health. Follow-up translational measures are discussed to bring new knowledge from lab to the patient. If validated in a large-scale clinical study, this approach might be instrumental for primary and secondary prevention in obese individual and patients diagnosed with diabetes. To this end, individualized prediction and treatments tailored to the person are strongly recommended to benefit the health condition of affected individuals.

The Cholesterol-Lowering Effect of Oats and Oat Beta Glucan: Modes of Action and Potential Role of Bile Acids and the Microbiome

Consumption of sufficient quantities of oat products has been shown to reduce host cholesterol and thereby modulate cardiovascular disease risk. The effects are proposed to be mediated by the gel-forming properties of oat β-glucan which modulates host bile acid and cholesterol metabolism and potentially removes intestinal cholesterol for excretion. However, the gut microbiota has emerged as a major factor regulating cholesterol metabolism in the host. Oat β-glucan has been shown to modulate the gut microbiota, particularly those bacterial species that influence host bile acid metabolism and production of short chain fatty acids, factors which are regulators of host cholesterol homeostasis. Given a significant role for the gut microbiota in cholesterol metabolism it is likely that the effects of oat β-glucan on the host are multifaceted and involve regulation of microbe-host interactions at the gut interface. Here we consider the potential for oat β-glucan to influence microbial populations in the gut with potential consequences for bile acid metabolism, reverse cholesterol transport (RCT), short-chain fatty acid (SCFA) production, bacterial metabolism of cholesterol and microbe-host signaling.

Probiotic Enterococcus faecalis AG5 effectively assimilates cholesterol and produces fatty acids including propionate

Probiotics are known for their health-promoting abilities through the production of various metabolites, and also benefits are membrane associated. Probiotic Enterococcus faecalis AG5 has been previously assessed for its probiotic properties and this study further strengthens that claim. Strain AG5 was inoculated with 0.3% sodium glychocholate (glycine conjugated) and bile salt mixture for different time periods. The percentage assimilation of cholesterol ranged from 14% to 33.1% in the bile salt mixture, but was slightly higher, ranging from 16.55% to 53.1%, in sodium thioglycocholate alone. Similarly, the bile salt hydrolysis activity was measured in terms of cholic acid release at different intervals. The overall range of cholic acid released ranged from 70.4 to 479 µg/mL. Fatty acid production is also an important criterion for a probiotic selection and it was found that the strain produced several long-chain fatty acids (LCFA) such as tetradecanoic acid, hexadecanoic acid, octadecanoic acid and bis(6-methylheptyl) phthalate. Besides LCFA, AG5 produced short-chain fatty acids (SCFA) such as propionic acid, which was estimated comparing liquid chromatography and mass spectrometry with standard SCFA. Thus the ability of deconjugation of bile salt and SCFA production is a value-added property of probiotic AG5, with the promise of being beneficial for human health.

Colonization and Gut Flora Modulation of Lactobacillus kefiranofaciens ZW3 in the Intestinal Tract of Mice

This study evaluated the distribution and colonization of Lactobacillus kefiranofaciens ZW3 and determined its capacity to modulate the gut microbiota in an animal model. Based on (1) fluorescence imaging, (2) flow cytometry, and (3) qPCR, we found that ZW3 successfully adhered to mouse mucous tissue and colonized the mouse ileum. Gut microbiota profiling was performed using high-throughput sequencing. After continuous intubation with ZW3 for 1 week, the proportion of Lachnospiraceae, a family of butyric acid-producing bacteria, increased at day 7 (11.9% at day 0 versus 18.4% at day 7). In addition, Lactobacillaceae showed an increasing trend (4% at day 0 versus 13% at day 7) that was accompanied by an observable decline in the Rikenellaceae family (1.58% at day 7, 0.14% at day 14, and 0.75% at day 21) in the tested mouse. The results demonstrate that ZW3 could successfully adhere to and colonize the mouse gut throughout the course of the experiment. The profiling analysis of the gut microbiota also provided evidence supporting the function of ZW3 in improving the intestinal flora of mice.

Soy extract and maltodextrin as microencapsulating agents for Lactobacillus acidophilus: a model approach

The present study aimed to optimise the microencapsulation of Lactobacillus acidophilus La-05 by spray drying, using soy extract and maltodextrin as encapsulants. Air inlet temperature, maltodextrin/soy extract ratio and feed flow rate were investigated through Central Composite Rotational Design (CCRD). Probiotic viability increased with increasing the proportion of soy extract. Temperature and feed flow rate had a negative effect. Particle diameter ranged from 4.97 to 8.82 μm, water activity from 0.25 to 0.52 and moisture from 2.30 to 7.01 g.100g-1 Particles produced following the optimised conditions (air temperature of 87 °C, maltodextrin/soy extract ratio of 2:3 w.w-1, feed flow rate of 0.54 L.h-1) reached Encapsulation yield (EY) of 83%. Thermogravimetry and FTIR analysis suggested that microcapsules could protect L. acidophilus cells against dehydration and heating. During storage, microencapsulated probiotic had high cell viability (reductions ranged between 0.12 and 1.72 log cycles). Soy extract/maltodextrin presented well-encapsulating properties of Lactobacillus acidophilus La-05.

Lactic acid bacteria with cholesterol-lowering properties for dairy applications: In vitro and in situ activity

Cholesterol-lowering activity is one of the most promising properties of lactic acid bacteria with probiotic characteristics. In the present study, 58 potentially probiotic lactic acid bacteria were tested for their ability to survive in vitro digestion and reduce cholesterol in a medium containing cholesterol and bile acids. The best-performing strains (Lactobacillus casei VC199, Lactobacillus paracasei ssp. paracasei SE160 and VC213, Lactobacillus plantarum VS166 and VS513, Enterococcus faecium VC223, and Enterococcus lactis BT161) resulted in a 42 to 55% reduction of the cholesterol level in broth and were further tested in cheese manufacture. The cholesterol content in all the cheeses decreased with ripening. All the strains were present in the cheese at levels higher than 10⁷ cfu/g until 60 d of ripening, the highest reductions (up to 23%) being obtained when Lb. paracasei ssp. paracasei VC213 and E. lactis BT161 were added during the cheese-making. The adjunct cultures had no negative effect on the sensory characteristics of the cheese. Thus, these strains with proven in vitro properties are good candidates for novel probiotic-containing formulations and could be used to functionalize foods such as dairy fermented products.

Gut Microbiome Associates With Lipid-Lowering Effect of Rosuvastatin in Vivo

Background: Statin has been widely used to treat hyperlipidemia because of its high potency in decreasing cholesterol levels. The present study aimed to examine the lipid-lowering effect of rosuvastatin and the composition, diversity and species abundance of gut microbiome in association with rosuvastatin efficacy. Trial registration: ChiCTR-ORC-17013212 at the First Affiliated Hospital of Dalian Medical University, November 2, 2017.

Results: Totally 64 patients with hyperlipidemia were treated with 10 mg/day of rosuvastatin for 4–8 weeks. Blood lipid indicators triglycerides (TG), total cholesterol (TC), high density lipoprotein (HDL), low-density lipoprotein cholesterol (LDL-C) were measured before and after the treatment. Stool samples were collected right after the treatment. Following total DNA extraction and PCR amplification of 16S rRNA gene, Illumina sequencing was performed for gut microbiome identification, classification and characterization. All the patients showed a significant blood lipid reduction after the treatment. The patients were grouped according to parallel manner design. Group I had 33 patients whose blood lipid levels dropped to the normal levels from week 4, with 58.5% reduction in LDL-C and 26.6% reduction in TC. Group II had 31 patients whose blood lipid levels were still above the normal levels after 8 weeks therapy, but with 41.9% reduction in LDL-C and 31.2% reduction in TC. Based on Operational Taxonomic Unit data, Alpha-diversity by Shannon Index was different between the two groups, and beta-diversity by Principle Component Analysis exhibited separated patterns of the two groups. The differences were also observed in the relative-abundance at phylum, family, and genus levels of the two groups. Linear discriminate analysis illustrated that the abundance of 29 taxa was higher in group I, while the abundance of other 13 taxa was higher in group II. Phyla Firmicutes and Fusobacteria had negative correlation to LDL-C level, but Cyanobacteria and Lentisphaerae had a positive correlation to LDL-C level. Moreover, gender and age were also found somehow correlated to microbial community composition.

Conclusion: Rosuvastatin therapy had different blood lipid-lowering effect on hyperlipidemia. The gut microbiota exhibited variation in community composition, diversity and taxa in association to rosuvastatin hypolipidemic effect. These results indicate that modulation of gut microflora, especially the negative/positive correlated species might strengthen statin efficacy in statin-inadequate patients.

Lactobacillus casei triggers a TLR mediated RACK-1 dependent p38 MAPK pathway in Caenorhabditis elegans to resist Klebsiella pneumoniae infection

In the present study, the effect of Lactic Acid Bacteria (LAB) was investigated at the molecular level using the model organism Caenorhabditis elegans against Klebsiella pneumoniae. Out of the 13 LAB screened, Lactobacillus casei displayed excellent protective efficacy by prolonging the survival of K. pneumoniae-infected nematodes. Pretreatment with L. casei significantly decreased bacterial colonization and rescued K. pneumoniae-infected C. elegans from various physiological impairments. The concomitant upregulation of key immune genes that regulate the TLR, RACK-1 as well as the p38 MAPK pathway rather than the IIS and ERK pathway suggested that the plausible immunomodulatory mechanism of L. casei could be by triggering the TLR, RACK-1 and p38 MAPK pathway. Furthermore, the hyper-susceptibility of L. casei treated loss-of-function mutants of the tol-1, RACK-1 and p38 MAPK pathway (sek-1 and pmk-1) to K. pneumoniae infection and gene expression analysis suggested that L. casei triggered a TLR mediated RACK-1 dependent p38 MAPK pathway to increase host resistance and protect nematodes against K. pneumoniae infection.

Probiotic Properties of Exopolysaccharide-Producing Lactobacillus Strains Isolated from Tempoyak

Tempoyak is a functional Malaysian food (an acid-fermented condiment) which is produced from the pulp of the durian (Durio zibethinus) fruit. The current study aimed to isolate and identify potential exopolysaccharide (EPS)-producing Lactobacillus strains from tempoyak for potential use as probiotics. Seven isolates (DUR2, DUR4, DUR5, DUR8, DUR12, DUR18, and DUR20) out of 44 were able to produce EPS, and exhibited resistance to acid and bile salt compared to the reference strains Lactobacillus rhmnosus (ATCC53103) and L. plantarum (ATCC8014). The seven isolated strains belonged to five different species-L. plantarum, L. fermentum, L. crispatus, L. reuteri, and L. pentosus-which were identified using API 50 CHL and 16S rRNA gene sequences (Polymerase chain reaction, PCR - based). The seven strains displayed different ability to produce EPS (100-850 mg/L). Isolates exhibited a high survivability to acid (pH 3.0), bile salts (0.3%), and gastrointestinal tract model (<70%). Results showed that the auto-aggregation and cell surface hydrophobicity ranged from 39.98% to 60.09% and 50.80% to 80.53%, respectively, whereas, the highest co-aggregation value (66.44%) was observed by L. fermentum (DUR8) with Pseudomonas aeruginosa. The isolates showed good inhibitory activity against tested pathogens, high antioxidant activity (32.29% to 73.36%), and good ability to reduce cholesterol (22.55% to 75.15%). Thus, the seven tested strains have value as probiotics.

Bifidobacteria and lactobacilli in the gut microbiome of children with non-alcoholic fatty liver disease: which strains act as health players?

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD), considered the leading cause of chronic liver disease in children, can often progress from non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH). It is clear that obesity is one of the main risk factors involved in NAFLD pathogenesis, even if specific mechanisms have yet to be elucidated. We investigated the distribution of intestinal bifidobacteria and lactobacilli in the stools of four groups of children: obese, obese with NAFL, obese with NASH, and healthy, age-matched controls (CTRLs).

MATERIAL AND METHODS

Sixty-one obese, NAFL and NASH children and 54 CTRLs were enrolled in the study. Anthropometric and metabolic parameters were measured for all subjects. All children with suspected NASH underwent liver biopsy. Bifidobacteria and lactobacilli were analysed in children's faecal samples, during a broader, 16S rRNA-based pyrosequencing analysis of the gut microbiome.

RESULTS

Three Bifidobacterium spp. (Bifidobacterium longum, Bifidobacterium bifidum, and Bifidobacterium adolescentis) and five Lactobacillus spp. (L. zeae, L. vaginalis, L. brevis, L. ruminis, and L. mucosae) frequently recurred in metagenomic analyses. Lactobacillus spp. increased in NAFL, NASH, or obese children compared to CTRLs. Particularly, L. mucosae was significantly higher in obese (p = 0.02426), NAFLD (p = 0.01313) and NASH (p = 0.01079) than in CTRLs. In contrast, Bifidobacterium spp. were more abundant in CTRLs, suggesting a protective and beneficial role of these microorganisms against the aforementioned diseases.

CONCLUSIONS

Bifidobacteria seem to have a protective role against the development of NAFLD and obesity, highlighting their possible use in developing novel, targeted and effective probiotics.

Comparative study of probiotic effects of Lactobacillus and Bifidobacteria strains on cholesterol levels, liver morphology and the gut microbiota in obese mice

BACKGROUND

Microbiome-modulating interventions are promising for treatment and prevention of metabolic syndrome. The number of probiotic strains demonstrated ability to decrease cholesterol level in vivo, however, it was poorly confirmed in a clinical setting. The aim was to study the effects of L. acidophilus IMV B-7279, L. casei IMV B-7280, B. animalіs VKL and B. animalіs VKB separately and in various compositions on the level of serum cholesterol, gut microbiota contents and liver morphology on a high-calorie-induced obesity model in BALB/c mice.

MATERIALS AND METHODS

We used for the study female BALB/c mice 6-8 weeks old (18-24 g). Experimental animals were fed by a fat-enriched diet (FED), and 8 experimental groups were formed (12 mice in each group) to test strains of probiotic bacteria L. delbrueckii subsp. bulgaricus IMV B-7281, L. casei IMV B-7280, B. animalіs VKL and B. animalіs VKB and compositions. We used ultrasound for in vivo assessment of the liver and visceral (mesenteric) fat size. In the blood serum of the obese mice, the level of cholesterol was estimated. The liver morphology and gut microbiota of obese mice were studied.

RESULTS

We revealed that after treatment with all of the studied probiotic bacteria and compositions of B. animalis VKL/B. animalis VKB/L. casei IMV B-7280, the weight of obese mice decreased, and cholesterol and its fraction levels in serum were reduced. The size of the liver slightly decreased after treatment with L. delbrueckii subsp. bulgaricus IMV B-7281, B. аnimalis VKB or probiotic compositions; we observed reduction of the mesenteric fat size after injection of all these probiotic bacteria (separately) and probiotic compositions. We defined the strain-dependent effects on serum lipid profiles, liver morphology and the gut microbiota. The B. animalis VKL/B. animalis VKB/L. casei IMV B-7280 composition effectively recovered the liver morphological structure of obese mice. The number of Lactobacillus spp., Bifidobacterium spp. and coliform bacteria increased, the number of staphylococci and streptococci reduced, and the number of microscopic fungi significantly decreased in the gut of obese mice after treatment with L. casei IMV B-7280, L. delbrueckii subsp. bulgaricus IMV B-7281, B. animalis (separately) or their compositions.

CONCLUSION

L. casei IMV B-7280 (separately) and a composition of B. animalis VKL/B. animalis VKB/L. casei IMV B-7280 are effective at decreasing the weight of obese mice, decreasing cholesterol level, restoring the liver morphology and beneficially modulating the gut microbiome in high-calorie-induced obesity.

Effects of microencapsulated Lactobacillus plantarum LIP-1 on the gut microbiota of hyperlipidaemic rats

The in vivo effects of administering free and microencapsulated Lactobacillus plantarum LIP-1 cells (2·0×109 colony-forming units/d) were evaluated in high-fat-diet-induced hyperlipidaemic rats. Results from real-time quantitative PCR targeting to LIP-1 cells showed a higher colon colonisation count of LIP-1 in the rats receiving microencapsulated cells compared with free cells (P<0·05). Moreover, the microencapsulated LIP-1 treatment resulted in a more obvious lipid-lowering effect (P<0·05). Meanwhile, their faecal samples had significantly less lipopolysaccharide-producing bacteria (especially Bilophila, Sutterella and Oscillibacter) and mucosa-damaging bacteria (Bilophila and Akkermansia muciniphila), whereas significantly more SCFA-producing bacteria (P<0·05) (namely Lactobacillus, Alloprevotella, Coprococcus, Eubacterium and Ruminococcus) and bacteria that potentially possessed bile salt hydrolase activity (Bacteroides, Clostridium, Eubacterium and Lactobacillus), and other beneficial bacteria (Alistipes and Turicibacter). Further, Spearman's correlation analysis showed significant correlations between some of the modulated gut bacteria and the serum lipid levels. These results together confirm that microcapsulation enhanced the colon colonisation of LIP-1 cells, which subsequently exhibited more pronounced effects in improving the gut microbiota composition of hyperlipidaemic rats and lipid reduction.

Gut Microbiota and Nonalcoholic Fatty Liver Disease: Insights on Mechanisms and Therapy

The gut microbiota plays critical roles in development of obese-related metabolic diseases such as nonalcoholic fatty liver disease (NAFLD), type 2 diabetes(T2D), and insulin resistance(IR), highlighting the potential of gut microbiota-targeted therapies in these diseases. There are various ways that gut microbiota can be manipulated, including through use of probiotics, prebiotics, synbiotics, antibiotics, and some active components from herbal medicines. In this review, we review the main roles of gut microbiota in mediating the development of NAFLD, and the advances in gut microbiota-targeted therapies for NAFLD in both the experimental and clinical studies, as well as the conclusions on the prospect of gut microbiota-targeted therapies in the future.

Dietary lipid content reorganizes gut microbiota and probiotic L. rhamnosus attenuates obesity and enhances catabolic hormonal milieu in zebrafish

In the present study, we explored whether dietary lipid content influences the gut microbiome in adult zebrafish. Diets containing three different lipid levels (high [HFD], medium [MFD], and low [LFD]) were administered with or without the supplementation of Lactobacillus rhamnosus (P) to zebrafish in order to explore how the dietary lipid content may influence the gut microbiome. Dietary lipid content shifted the gut microbiome structure. The addition of L. rhamnosus in the diets, induced transcriptional reduction of orexigenic genes, upregulation of anorexigenic genes, and transcriptional decrease of genes involved in cholesterol and triglyceride (TAG) metabolism, concomitantly with lower content of cholesterol and TAG. Probiotic feeding also decreased nesfatin-1 peptide in HFD-P and attenuated weight gain in HFD-P and MFD-P fed zebrafish, but not in LFD-P group. Intestinal ultrastructure was not affected by dietary fat level or probiotic inclusion. In conclusion, these findings underline the role of fat content in the diet in altering gut microbiota community by shifting phylotype composition and highlight the potential of probiotics to attenuate high-fat diet-related metabolic disorder.

Effects of Bifidobacterium animalis subsp. lactis BB-12® on the lipid/lipoprotein profile and short chain fatty acids in healthy young adults: a randomized controlled trial

Background

Some probiotics have hypocholesterolemic effects in animal studies, which are mediated, in part, by increases in fecal short chain fatty acids (SCFAs). Clinical trials of probiotics on lipids/lipoproteins are inconsistent.

Objective

We examined the effects of Bifidobacterium animalis subsp. lactis BB-12^® (BB-12^®) (3.16 × 10⁹ CFUs/day) on lipids and lipoproteins and fecal excretion of SCFAs in healthy adults.

Methods

In a randomized, partially blinded, 4-period, crossover study, 30 adults (11 men, 19 women) aged 18–40 years were randomly assigned to: 1) yogurt smoothie with no BB-12^® (YS), 2) yogurt smoothie with BB-12^® added pre-fermentation (PRE), 3) yogurt smoothie with BB-12^® added post-fermentation (POST), 4) BB-12^® containing capsule (CAP). We measured serum lipids/lipoproteins, glucose, insulin, C-reactive protein (CRP), and fecal SCFAs at baseline and after each treatment period.

Results

Total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), and triglycerides (TGs) did not differ after the PRE, POST, and CAP periods versus the YS or between treatments. Compared to baseline, fecal acetate was significantly increased after the YS (Δ = 211.89 ± 75.87 μg/g, P = 0.007) and PRE (Δ = 204.98 ± 75.70 μg/g, P = 0.009) periods. The percent increase in fecal acetate was significantly greater after the YS versus the POST period (52.2 ± 13.2% vs. 24.5 ± 13.2%, P = 0.023). Fecal total SCFAs, propionate and butyrate did not differ between treatment periods. Fecal total SCFAs were negatively associated with TC (r = -0.22, P = 0.01), LDL-C (r = -0.24, P = 0.004), age (r = -0.33, P < 0.001), and waist circumference (r = -0.25, P = 0.003).

Conclusions

BB-12^® supplementation did not improve lipids, lipoproteins and total and individual fecal SCFAs. Fecal SCFAs were negatively associated with TC, LDL-C, age, and waist circumference.

Trial registration

This trial was registered at clinicaltrials.gov as NCT01399996.

Selection of Cholesterol-Lowering Lactic Acid Bacteria and its Effects on Rats Fed with High-Cholesterol Diet

High cholesterol level in serum is a major factor of influence for coronary heart disease. The cholesterol-lowering ability of lactic acid bacteria (LAB) without side effects makes them more and more attractive. Seventy-nine strains of LAB isolated from fermented food were screened in vitro for their ability to assimilate cholesterol. Then, ten strains which exhibited higher ability of cholesterol assimilation were investigated with the characteristics of acidic resistance, bile salt tolerance, and cell adhesion. According to the results, the best strain LP96 was picked out, and used to evaluate its effects on the high-cholesterol diet-fed rats. The results demonstrated that the levels of serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol, and liver TC and TG were reduced significantly in the groups that received the strain LP96 solution compared with the model group, and that the serum high-density lipoprotein cholesterol levels were increased without any significant difference. Furthermore, LP96 also showed good antioxidative activity and improvement of intestinal microbial balance in the rats. Thus, LP96 may be a promising probiotics with potential cholesterol-lowering ability.

Characterization of Selected Lactobacillus Strains for Use as Probiotics

The aim of this study was to evaluate the functional properties of lactic acid bacteria from various sources and to identify strains for use as probiotics. Ten Lactobacillus strains were selected and their properties such as bile tolerance, acid resistance, cholesterol assimilation activity, and adherence to HT-29 cells were assessed to determine their potential as probiotics. Lactobacillus sp. JNU 8829, L. casei MB3, L. sakei MA9, L. sakei CH8, and L. acidophilus M23 were found to show full tolerance to the 0.3% bile acid. All strains without L. acidophilus M23 were the most acid-tolerant strains. After incubating the strains at pH 2.5 for 2 h, their viability decreased by 3 Log cells. Some strains survived at pH 2.5 in the presence of pepsin and 0.3% bile acid. Lactobacillus sp. JNU 8829, L. acidophilus KU41, L. acidophilus M23, L. fermentum NS2, L. plantarum M13, and L. plantarum NS3 were found to reduce cholesterol levels by >50% in vitro. In the adhesion assay, Lactobacillus sp. JNU 8829, L. casei MB3, L. sakei MA9, and L. sakei CH8 showed higher adhesion activities after 2 h of co-incubation with the intestinal cells. The results of this comprehensive analysis shows that this new probiotic strain named, Lactobacillus sp. JNU 8829 could be a promising candidate for dairy products.

Effect of different calcium salts and methods for triggering gelation on the characteristics of microencapsulated Lactobacillus plantarum LIP-1

Probiotic Lactobacillus plantarum isolate LIP-1 was microencapsulated in milk protein matrices by means of rennet-induced gelation combined with an emulsification technique.

Exopolysaccharide-producing probiotic Lactobacilli reduce serum cholesterol and modify enteric microbiota in ApoE-deficient mice

BACKGROUND

Probiotic bacteria have been associated with a reduction in cardiovascular disease risk, a leading cause of death and disability.

OBJECTIVES

The aim of this study was to assess the impact of dietary administration of exopolysaccharide-producing probiotic Lactobacillus cultures on lipid metabolism and gut microbiota in apolipoprotein E (apoE)-deficient mice.

METHODS

First, we examined lipid metabolism in response to dietary supplementation with recombinant β-glucan-producing Lactobacillus paracasei National Food Biotechnology Centre (NFBC) 338 expressing the glycosyltransferase (Gtf) gene from Pediococcus parvulus 2.6 (GTF), and naturally exopolysaccharide-producing Lactobacillus mucosae Dairy Product Culture Collection (DPC) 6426 (DPC 6426) compared with the non-β-glucan-producing isogenic control strain Lactobacillus paracasei NFBC 338 (PNZ) and placebo (15% wt:vol trehalose). Second, we examined the effects on the gut microbiota of dietary administration of DPC 6426 compared with placebo. Probiotic Lactobacillus strains at 1 × 10(9) colony-forming units/d per animal were administered to apoE(-/-) mice fed a high-fat (60% fat)/high-cholesterol (2% wt:wt) diet for 12 wk. At the end of the study, aortic plaque development and serum, liver, and fecal variables involved in lipid metabolism were analyzed, and culture-independent microbial analyses of cecal content were performed.

RESULTS

Total cholesterol was reduced in serum (P < 0.001; ∼33-50%) and liver (P < 0.05; ∼30%) and serum triglyceride concentrations were reduced (P < 0.05; ∼15-25%) in mice supplemented with GTF or DPC 6426 compared with the PNZ or placebo group, respectively. In addition, dietary intervention with GTF led to increased amounts of fecal cholesterol excretion (P < 0.05) compared with all other groups. Compositional sequencing of the gut microbiota revealed a greater prevalence of Porphyromonadaceae (P = 0.001) and Prevotellaceae (P = 0.001) in the DPC 6426 group and lower proportions of Clostridiaceae (P < 0.05), Peptococcaceae (P < 0.001), and Staphylococcaceae (P < 0.01) compared with the placebo group.

CONCLUSION

Ingestion of exopolysaccharide-producing lactobacilli resulted in seemingly favorable improvements in lipid metabolism, which were associated with changes in the gut microbiota of mice.

Cholesterol-lowering potentials of lactic acid bacteria based on bile-salt hydrolase activity and effect of potent strains on cholesterol metabolism in vitro and in vivo

This study collected different probiotic isolates from animal and plant sources to evaluate the bile-salt hydrolase activity of probiotics in vitro. The deconjugation potential of bile acid was determined using high-performance liquid chromatography. HepG2 cells were cultured with probiotic strains with high BSH activity. The triglyceride (TG) and apolipoprotein B (apo B) secretion by HepG2 cells were evaluated. Our results show that the BSH activity and bile-acid deconjugation abilities of Pediococcus acidilactici NBHK002, Bifidobacterium adolescentis NBHK006, Lactobacillus rhamnosus NBHK007, and Lactobacillus acidophilus NBHK008 were higher than those of the other probiotic strains. The cholesterol concentration in cholesterol micelles was reduced within 24 h. NBHK007 reduced the TG secretion by 100% after 48 h of incubation. NBHK002, NBHK006, and NBHK007 could reduce apo B secretion by 33%, 38%, and 39%, respectively, after 24 h of incubation. The product PROBIO S-23 produced a greater decrease in the total concentration of cholesterol, low-density lipoprotein, TG, and thiobarbituric acid reactive substance in the serum or livers of hamsters with hypercholesterolemia compared with that of hamsters fed with a high-fat and high-cholesterol diet. These results show that the three probiotic strains of lactic acid bacteria are better candidates for reducing the risk of cardiovascular disease.

Effects of lactic acid bacteria isolated from fermented mustard on lowering cholesterol

OBJECTIVE

To evaluate the ability of lactic acid bacteria (LAB) strains isolated from fermented mustard to lower the cholesterol in vitro.

METHODS

The ability of 50 LAB strains isolated from fermented mustard on lowering cholesterol in vitro was determined by modified o-phtshalaldehyde method. The LAB isolates were analyzed for their resistance to acid and bile salt. Strains with lowering cholesterol activity, were determined adherence to Caco-2 cells.

RESULTS

Strain B0007, B0006 and B0022 assimilated more cholesterol than BCRC10474 and BCRC 17010. The isolated strains showed tolerance to pH 3.0 for 3 h despite variations in the degree of viability and bile-tolerant strains, with more than 10(8) CFU/mL after incubation for 24 h at 1% oxigall in MRS. In addition, strain B0007 and B0022 identified as Lactobacillus plantarum with 16S rDNA sequences were able to adhere to the Caco-2 cell lines.

CONCLUSIONS

These strains B0007 and B0022 may be potential functional sources for cholesterol-lowering activities as well as adhering to Caco-2 cell lines.

Molecular characterization of lactobacilli isolated from fermented idli batter

Lactic acid bacteria are non pathogenic organism widely distributed in nature typically involved in a large number of spontaneous food fermentation. The purpose of this study was to characterize the bacteriocinogenic lactobacilli from fermented idli batter which can find application in biopreservation and biomedicine. Eight most promising lactobacilli were chosen from twenty two isolates based on their spectrum of activity against other lactic acid bacteria and pathogens. The eight lactobacilli were characterized based on the various classical phenotypic tests, physiological tests and biochemical tests including various carbohydrate utilization profiles. All isolates were homo fermentative, catalase, and gelatin negative. Molecular characterization was performed by RAPD, 16S rRNA analysis, 16S ARDRA, and Multiplex PCR for species identification. RAPD was carried out using the primer R2 and M13. Five different clusters were obtained based on RAPD indicating strain level variation. 16S rRNA analysis showed 99 to 100% homology towards Lactobacillus plantarum. The restriction digestion pattern was similar for all the isolates with the restriction enzyme AluI. The subspecies were identified by performing Multiplex PCR using species specific primer. Among the five clusters, three clusters were clearly identified as Lactobacillus plantarum subsp. plantarum, Lactobacillus pentosus, and Lactobacillus plantarum subsp. argentoratensis.

The effects of two Lactobacillus plantarum strains on rat lipid metabolism receiving a high fat diet

The aim of our study was to evaluate the effects of the different probiotic strains, Lactobacillus plantarum LS/07 and Lactobacillus plantarum Biocenol LP96, on lipid metabolism and body weight in rats fed a high fat diet. Compared with the high fat diet group, the results showed that Lactobacillus plantarum LS/07 reduced serum cholesterol and LDL cholesterol, but Lactobacillus plantarum Biocenol LP96 decreased triglycerides and VLDL, while there was no change in the serum HDL level and liver lipids. Both probiotic strains lowered total bile acids in serum. Our strains have no significant change in body weight, gain weight, and body fat. These findings indicate that the effect of lactobacilli on lipid metabolism may differ among strains and that the Lactobacillus plantarum LS/07 and Lactobacillus plantarum Biocenol LP96 can be used to improve lipid profile and can contribute to a healthier bowel microbial balance.

Hypocaloric diet supplemented with probiotic cheese improves body mass index and blood pressure indices of obese hypertensive patients--a randomized double-blind placebo-controlled pilot study

Background

Gut lactobacilli can affect the metabolic functions of healthy humans. We tested whether a 1500 kcal/d diet supplemented with cheese containing the probiotic Lactobacillus plantarum TENSIA (Deutsche Sammlung für Mikroorganismen, DSM 21380) could reduce some symptoms of metabolic syndrome in Russian adults with obesity and hypertension.

Methods

In this 3-week, randomized, double-blind, placebo-controlled, parallel pilot study, 25 subjects ingested probiotic cheese and 15 ingested control cheese. Fifty grams of each cheese provided 175 kcal of energy. Blood pressure (BP), anthropometric characteristics, markers of liver and kidney function, metabolic indices (plasma glucose, lipids, and cholesterol), and urine polyamines were measured. Counts of fecal lactobacilli and L. plantarum TENSIA were evaluated using molecular methods. The data were analyzed by t-test for independent samples and Spearman’s partial correlation analysis.

Results

The probiotic L. plantarum TENSIA was present in variable amounts (529.6 ± 232.5 gene copies) in 16/25 (64%) study subjects. Body mass index (BMI) was significantly reduced (p = 0.031) in the probiotic cheese group versus the control cheese group. The changes in BMI were closely associated with the water content of the body (r = 0.570, p = 0.0007) when adjusted for sex and age. Higher values of intestinal lactobacilli after probiotic cheese consumption were associated with higher BMI (r = 0.383, p = 0.0305) and urinary putrescine content (r = 0.475, p = 0.006). In patients simultaneously treated with BP-lowering drugs, similar reductions of BP were observed in both groups. A positive association was detected between TENSIA colonization and the extent of change of morning diastolic BP (r = 0.617, p = 0.0248) and a trend toward lower values of morning systolic BP (r = −0.527, p = 0.0640) at the end of the study after adjusting for BMI, age, and sex.

Conclusion

In a pilot study of obese hypertensive patients, a hypocaloric diet supplemented with a probiotic cheese helps to reduce BMI and arterial BP values, recognized symptoms of metabolic syndrome.

Trial registration

Current Controlled Trials ISRCTN76271778

Probiotic properties of Lactobacillus strains isolated from Tibetan kefir grains

The objective of this study was to evaluate the functional properties of lactic acid bacteria (LAB) isolated from Tibetan kefir grains. Three Lactobacillus isolates identified as Lactobacillus acidophilus LA15, Lactobacillus plantarum B23 and Lactobacillus kefiri D17 that showed resistance to acid and bile salts were selected for further evaluation of their probiotic properties. The 3 selected strains expressed high in vitro adherence to Caco-2 cells. They were sensitive to gentamicin, erythromycin and chloramphenicol and resistant to vancomycin with MIC values of 26 µg/ml. All 3 strains showed potential bile salt hydrolase (BSH) activity, cholesterol assimilation and cholesterol co-precipitation ability. Additionally, the potential effect of these strains on plasma cholesterol levels was evaluated in Sprague-Dawley (SD) rats. Rats in 4 treatment groups were fed the following experimental diets for 4 weeks: a high-cholesterol diet, a high-cholesterol diet plus LA15, a high-cholesterol diet plus B23 or a high-cholesterol diet plus D17. The total cholesterol, triglyceride and low-density lipoprotein cholesterol levels in the serum were significantly (P<0.05) decreased in the LAB-treated rats compared with rats fed a high-cholesterol diet without LAB supplementation. The high-density lipoprotein cholesterol levels in groups B23 and D17 were significantly (P<0.05) higher than those in the control and LA15 groups. Additionally, both fecal cholesterol and bile acid levels were significantly (P<0.05) increased after LAB administration. Fecal lactobacilli counts were significantly (P<0.05) higher in the LAB treatment groups than in the control groups. Furthermore, the 3 strains were detected in the rat small intestine, colon and feces during the feeding trial. The bacteria levels remained high even after the LAB administration had been stopped for 2 weeks. These results suggest that these strains may be used in the future as probiotic starter cultures for manufacturing novel fermented foods.