Impact of supplementation with a food-derived microbial community on obesity-associated inflammation and gut microbiota composition

Effect of Lactobacillus kefiri, in Conjunction with PENS T6 and a Hypocaloric Diet, on Weight Loss, Hypertension and Laboratory Glycemic and Lipid Profile

The pathogenesis of obesity has been linked to alterations in gut microorganisms. The aim of this study was to investigate the effect of Lactobacillus kefiri, together with PENS T6 and a hypocaloric diet, on weight loss, hypertension and laboratory glycemic and lipid profile. A prospective non-randomized study was conducted involving adult patients with a body mass index (BMI) > 30 kg/m2. Patients were divided into two groups: those undergoing PENS-T6 and hypocaloric diet (PENS-Diet Group) and those undergoing the same PENS-T6 scheme and hypocaloric diet, but additionally receiving probiotics including Lactobacillus kefiri (PENS-Diet + L. kefiri Group). Weight loss was assessed at the end of the treatment, and analytical glycemic and lipid profile, and microbiological analysis of feces were performed before and after treatment. The addition of Lactobacillus kefiri to PENS T6 and a low-calorie diet, increases weight loss and further improves the glycemic and lipid profile. L. kefiri also causes a further improvement in obesity-associated dysbiosis, mainly by increasing the muconutritive (Akkermansia muciniphila) and regulatory (Bifidobacterium spp.) microbiome, and the Phylum Bacteroidetes (Prevotella spp.) and decreasing the Firmicutes/Bacteroidetes ratio.

Composition of the intestinal microbiota and its variations between the second and third trimesters in women with gestational diabetes mellitus and without gestational diabetes mellitus

Objective

This study was designed to explore the composition of the intestinal microbiota and its longitudinal variation between the second trimester (T2) and the third trimester (T3) in women with gestational diabetes mellitus (GDM) and pregnant women with normal glucose tolerance.

Methods

This observational study was conducted at Peking Union Medical College Hospital (PUMCH). Women with GDM and pregnant women with normal glucose tolerance were enrolled in the study, and fecal samples were collected during T2 (weeks 24~28) and T3 (weeks 34~38). Fecal samples were analyzed from 49 women with GDM and 42 pregnant women with normal glucose tolerance. The 16S rRNA gene amplicon libraries were sequenced to analyze the microbiota and QIIME2 was used to analyze microbiome bioinformatics.

Results

The four dominant phyla that Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria which accomplish about 99% of the total relative abundance did not significantly change between the T2 and T3 in the GDM and healthy groups. At the genus level, the relative abundance of Scardovia (0 vs. 0.25%, P = 0.041) and Propionibacterium (0 vs. 0.29%, P = 0.041) increased significantly in the control group, but not in the GDM group. At the phylum level, the relative abundance of Firmicutes and Actinobacteria was significantly different between women with GDM and pregnant women with normal glucose tolerance in both T2 and T3. In T2 and T3, the relative abundances of unidentified_Lachnospiraceae, Blautia, and Parabacteroides were significantly higher in the GDM group than in the control group (P<0.05). The relative abundance of Bifidobacterium in the GDM group was lower than in the control group in both T2 and T3.

Conclusions

The intestinal microbiota composition was stable from T2 to T3 in the GDM and control groups; however, the intestinal microbiota composition was different between the two groups.

Interaction between gut microbiota metabolites and dietary components in lipid metabolism and metabolic diseases

Gut microbiota composition has caused perplexity in developing precision therapy to cure metabolic disorders. However, recent research has focused on using daily diet and natural bioactive compounds to correct gut microbiota dysbiosis and regulate host metabolism. Complex interactions between the gut microbiota and dietary compounds disrupt or integrate the gut barrier and lipid metabolism. In this review, we investigate the role of diet and bioactive natural compounds in gut microbiota dysbiosis and also the modulation of lipid metabolism by their metabolites. Recent studies have revealed that diet, natural compounds and phytochemicals impact significantly on lipid metabolism in animals and humans. These findings suggest that dietary components or natural bioactive compounds have a significant impact on microbial dysbiosis linked to metabolic diseases. The interaction between dietary components or natural bioactive compounds and gut microbiota metabolites can regulate lipid metabolism. Additionally, natural products can shape the gut microbiota and improve barrier integrity by interacting with gut metabolites and their precursors, even in unfavourable conditions, potentially contributing to the alignment of host physiology.

Fermented Foods in the Management of Obesity: Mechanisms of Action and Future Challenges

Fermented foods are part of the staple diet in many different countries and populations and contain various probiotic microorganisms and non-digestible prebiotics. Fermentation is the process of breaking down sugars by bacteria and yeast species; it not only enhances food preservation but can also increase the number of beneficial gut bacteria. Regular consumption of fermented foods has been associated with a variety of health benefits (although some health risks also exist), including improved digestion, enhanced immunity, and greater weight loss, suggesting that fermented foods have the potential to help in the design of effective nutritional therapeutic approaches for obesity. In this article, we provide a comprehensive overview of the health effects of fermented foods and the corresponding mechanisms of action in obesity and obesity-related metabolic abnormalities.

The Gut Microbial Signature of Gestational Diabetes Mellitus and the Association With Diet Intervention

Gestational diabetes mellitus (GDM) is a high-risk pregnancy complication that is associated with metabolic disorder phenotypes, such as abnormal blood glucose and obesity. The link between microbiota and diet management contributes to metabolic homeostasis in GDM. Therefore, it is crucial to understand the structure of the gut microbiota in GDM and to explore the effect of dietary management on the microbiota structure. In this study, we analyzed the composition of the gut microbiota between 27 GDM and 30 healthy subjects at two time points using Illumina HiSeq 2500 platform. The taxonomy analyses suggested that the overall bacteria clustered by diabetes status, rather than diet intervention. Of particular interest, the phylum Acidobacteria in GDM was significantly increased, and positively correlated with blood glucose levels. Moreover, Partial least-squares discriminant analysis (PLS-DA) revealed that certain genera in the phyla Firmicutes, Bacteroidetes, Proteobacteria, and Lentisphaerae characterized the GDM gut microbiota. Correlation analysis indicated that blood glucose levels and BMI index were correlated with the relative abundance of SCFAS-producing genera. Through the comparison between the GDM and healthy samples with or without diet intervention, we discovered that the role of short-term diet management in GDM processes is associated with the change in the Firmicutes/Bacteroidetes ratio and some specific taxa, rather than an alternative gut microbial pattern. Our study have important implications for understanding the beneficial effects of diet intervention on the specific gut microbiota and thus possibly their metabolism in pregnant women with GDM.

Effect of Continuous Feeding of Ayu-Narezushi on Lipid Metabolism in a Mouse Model of Metabolic Syndrome

Ayu-narezushi, a traditional Japanese fermented food, comprises abundant levels of lactic acid bacteria (LAB) and free amino acids. This study aimed to examine the potential beneficial effects of ayu-narezushi and investigated whether ayu-narezushi led to improvements in the Tsumura Suzuki obese diabetes (TSOD) mice model of spontaneous metabolic syndrome because useful LAB are known as probiotics that regulate intestinal function. In the present study, the increased body weight of the TSOD mice was attenuated in those fed the ayu-narezushi-comprised chow (ayu-narezushi group) compared with those fed the normal rodent chow (control group). Serum triglyceride and cholesterol levels were significantly lower in the Ayu-narezushi group than in the control group at 24 weeks of age. Furthermore, hepatic mRNA levels of carnitine-palmitoyl transferase 1 and acyl-CoA oxidase, which related to fatty acid oxidation, were significantly increased in the ayu-narezushi group than in the control group at 24 weeks of age. In conclusion, these results suggested that continuous feeding with ayu-narezushi improved obesity and dyslipidemia in the TSOD mice and that the activation of fatty acid oxidation in the liver might contribute to these improvements.

Impacts of gut microbiota on gestational diabetes mellitus: a comprehensive review

BACKGROUND

Gestational diabetes mellitus (GDM) is a condition that seriously threatens mother and child health. The incidence of GDM has increased worldwide in the past decades. In addition, the complications of GDM such as type 2 diabetes (T2DM) and neonatal malformations could negatively affect the living quality of mothers and their children.

AIM

It has been widely known that the imbalance of gut microbiota or called 'gut dysbiosis' plays a key role in the development of insulin resistance and chronic low-grade inflammation in T2DM patients. However, the impacts of gut microbiota on GDM remain controversial. Here, we aim to comprehensively review the alterations of gut microbiota in GDM mothers and their offspring.

RESULTS

The alterations of Firmicutes/Bacteroidetes (F/B) ratio, short-chain fatty acid (SCFA)-producing bacteria, bacteria with probiotics properties and gram-negative lipopolysaccharide (LPS)-producing bacteria play a vital role in the development of GDM. The beneficial roles of gut microbiota modification (probiotics, synbiotics and lifestyle modification) as a treatment of GDM were found in some, but not all studies.

CONCLUSION

In the near future, gut microbiota modification may be considered as one of the standard treatments for GDM. Moreover, further studies regarding the specific gut microbiota that are associated with the early development of GDM are required. This may contribute to the novel diagnostic markers for early stages of GDM.

Toxic effects of the food additives titanium dioxide and silica on the murine intestinal tract: Mechanisms related to intestinal barrier dysfunction involved by gut microbiota

This study aimed to compare the effects of three food-grade particles (micro-TiO₂, nano-TiO₂, and nano-SiO₂) on the murine intestinal tract and to investigate their potential mechanisms of action. A 28-day oral exposure murine model was established. Samples of blood, intestinal tissues and colon contents were collected for detection. The results showed that all three particles could cause inflammatory damage to the intestine, with nano-TiO₂ showing the strongest effects. Exposure also led to changes in gut microbiota, especially mucus-associated bacteria. Our results suggest that the toxic effects on the intestine were due to reduced intestinal mucus barrier function and an increase in metabolite lipopolysaccharides which activated the expression of inflammatory factors downstream. In mice exposed to nano-TiO₂, the intestinal PKC/TLR4/NF-κB signalling pathway was activated. These findings will raise awareness of toxicities associated with the use of food-grade TiO₂ and SiO₂.

Addition of Probiotics to Anti-Obesity Therapy by Percutaneous Electrical Stimulation of Dermatome T6. A Pilot Study

Obesity is becoming a pandemic and percutaneous electrical stimulation (PENS) of dermatome T6 has been demonstrated to reduce stomach motility and appetite, allowing greater weight loss than isolated hypocaloric diets. However, modulation of intestinal microbiota could improve this effect and control cardiovascular risk factors. Our objective was to test whether addition of probiotics could improve weight loss and cardiovascular risk factors in obese subjects after PENS and a hypocaloric diet. A pilot prospective study was performed in patients (n = 20) with a body mass index (BMI) > 30 kg/m2. Half of them underwent ten weeks of PENS in conjunction with a hypocaloric diet (PENS-Diet), and the other half was treated with a PENS-Diet plus multistrain probiotics (L. plantarum LP115, B. brevis B3, and L. acidophilus LA14) administration. Fecal samples were obtained before and after interventions. The weight loss and changes in blood pressure, glycemic and lipid profile, and in gut microbiota were investigated. Weight loss was significantly higher (16.2 vs. 11.1 kg, p = 0.022), whereas glycated hemoglobin and triglycerides were lower (-0.46 vs. -0.05%, p = 0.032, and -47.0 vs. -8.5 mg/dL, p = 0.002, respectively) in patients receiving PENS-Diet + probiotics compared with those with a PENS-Diet. Moreover, an enrichment of anti-obesogenic bacteria, including Bifidobacterium spp, Akkermansia spp, Prevotella spp, and the attenuation of the Firmicutes/Bacteroidetes ratio were noted in fecal samples after probiotics administration. In obese patients, the addition of probiotics to a PENS intervention under a hypocaloric diet could further improve weight loss and glycemic and lipid profile in parallel to the amelioration of gut dysbiosis.

Anti-atherosclerotic effects of Lactobacillus plantarum ATCC 14917 in ApoE-/- mice through modulation of proinflammatory cytokines and oxidative stress

Atherosclerosis is a chronic inflammatory disease mediated by monocyte infiltration and cholesterol deposition into the subendothelial area, resulting in foam cell development. Probiotics are live bacteria that are beneficial for health when administered orally in adequate amounts. In this study, 8-week-old atherosclerosis-prone apolipoprotein E-deficient (ApoE^-/-) mice were fed with or without Lactobacillus plantarum ATCC 14917 per day for 12 weeks. Serum was collected to analyse the lipid profile, oxidative status and proinflammatory cytokines. The heart was isolated to quantify the atherosclerotic lesion size in the aortic arch. Quantitative real-time polymerase chain reaction was performed to determine the expression levels of tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-1β in the aorta. The proteins extracted from the aorta were used for Western blot analysis to assess the expression levels of nuclear factor kappa B (NF-κB) and inhibitor of NF-κB (IκBα). The composition of gut microbiota was also examined through high-throughput sequencing. Results showed that the daily consumption of L. plantarum ATCC 14917 had no effect on body weight and lipid profile. L. plantarum ATCC 14917 treatment significantly inhibited atherosclerotic lesion formation. In addition, the oxLDL, MDA, TNF-α and IL-1β levels were significantly reduced, whereas the SOD level was induced in the bacteria + high-fat diet group. Furthermore, the administration of L. plantarum ATCC 14917 significantly attenuated IκBα protein degradation and inhibited the translocation of P65 subunits of NF-κB. L. plantarum ATCC 14917 treatment also modulated the composition of gut microbiota in ApoE^-/- mice. Our findings showed that L. plantarum ATCC 14917 supplementation decreases the progression of atherosclerotic lesion formation by alleviating the inflammatory process and lowering oxidative stress.

Probiotics and dietary intervention modulate the colonic mucosa-associated microbiota in high-fat diet populations

BACKGROUND/AIMS

Alterations in the gut microbiota due to a high-fat diet and diet-induced illness have been found in both mouse models and humans. Observational studies suggest that probiotic administration and diet shifts may treat diet-related diseases. However, the effect of these interventions on the colonic mucosa has not yet been elucidated. This study investigated the efficacy of probiotic supplementation and dietary intervention as prophylactic tools under high-fat diet conditions.

MATERIALS AND METHODS

A total of 36 volunteers that normally consumed a high-fat diet were enrolled and treated with either a control diet, a low-fat dietary intervention, Bifidobacterium triple viable capsule therapy, or a combination of a low-fat diet and Bifidobacterium triple viable capsule therapy. Pyrosequencing of the V3 and V4 regions of the 16S rRNA genes was conducted to determine the extent to which probiotics and dietary intervention altered the mucosal microbiota.

RESULTS

This study demonstrated that interventional treatment with probiotics and a low-fat diet increased the diversity of the mucosal microbes, dietary intervention alone produced the most significant effect, whereas the combined intervention exhibited no synergetic improvement. Pyrosequencing demonstrated that probiotics and dietary intervention significantly elevated the abundance of some bacterial taxa assigned to the phylum Firmicutes and the beneficial genera Prevotella, Gemmiger, Coprococcus, and Faecalibacterium and reduced some harmful bacterial taxa assigned to the phylum Proteobacteria and genus Streptophyta.

CONCLUSION

The results of this study suggested that the addition of probiotics and dietary intervention could improve the composition of the colonic mucosal microbiota in high-fat diet populations.

Diet change affects intestinal microbiota restoration and improves vertical sleeve gastrectomy outcome in diet-induced obese rats

Purpose

Obesity, a worldwide health problem, is linked to an abnormal gut microbiota and is currently most effectively treated by bariatric surgery. Our aim was to characterize the microbiota of high-fat fed Sprague–Dawley rats when subjected to bariatric surgery (i.e., vertical sleeve gastrectomy) and posterior refeeding with either a high-fat or control diet. We hypothesized that bariatric surgery followed by the control diet was more effective in reverting the microbiota modifications caused by the high-fat diet when compared to either of the two factors alone.

Methods

Using next-generation sequencing of ribosomal RNA amplicons, we analyzed and compared the composition of the cecal microbiota after vertical sleeve gastrectomy with control groups representing non-operated rats, control fed, high-fat fed, and post-operative diet-switched animals. Rats were fed either a high-fat or control low-fat diet and were separated into three comparison groups after eight weeks comprising no surgery, sham surgery, and vertical sleeve gastrectomy. Half of the rats were then moved from the HFD to the control diet. Using next-generation sequencing of ribosomal RNA amplicons, we analyzed the composition of the cecal microbiota of rats allocated to the vertical sleeve gastrectomy group and compared it to that of the non-surgical, control fed, high-fat fed, and post-operative diet-switched groups. Additionally, we correlated different biological parameters with the genera exhibiting the highest variation in abundance between the groups.

Results

The high-fat diet was the strongest driver of altered taxonomic composition, relative microbial abundance, and diversity in the cecum. These effects were partially reversed in the diet-switched cohort, especially when combined with sleeve gastrectomy, resulting in increased diversity and shifting relative abundances. Several highly-affected genera were correlated with obesity-related parameters.

Conclusions

The dysbiotic state caused by high-fat diet was improved by the change to the lower fat, higher fiber control diet. Bariatric surgery contributed significantly and additively to the diet in restoring microbiome diversity and complexity. These results highlight the importance of dietary intervention following bariatric surgery for improved restoration of cecal diversity, as neither surgery nor change of diet alone had the same effects as when combined.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02190-8) contains supplementary material, which is available to authorized users.

Anti-Obesity Effects of Lactobacillus fermentum CQPC05 Isolated from Sichuan Pickle in High-Fat Diet-Induced Obese Mice through PPAR-α Signaling Pathway

Sichuan pickle is a traditional fermented food in China which is produced by the spontaneous fermentation of Chinese cabbage. In this study, the anti-obesity effects of a new lactic acid bacterium (Lactobacillus fermentum CQPC05, LF-CQPC05) isolated from Sichuan pickles were assessed in vivo. An obese animal model was established in mice by inducing obesity with high-fat diet. Both serum and tissues were collected from the mice, and then subjected to qPCR and Western blot analyses. The results showed that LF-CQPC05 could decrease the values of hepatosomatic, epididymal fat, and perirenal fat indices that were induced by a high-fat diet in mice. Moreover, LF-CQPC05 reduced the levels of alanine aminotransferase (ALT), aspartate aminotransaminase (AST), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C), and increased the level of high-density lipoprotein cholesterol (HDL-C) in both serum samples and liver tissues of obese mice fed with a high-fat diet. Pathological observations demonstrated that LF-CQPC05 could alleviate the obesity-induced pathological changes in the liver tissue of mice, and reduce the degree of adipocyte enlargement. The results of qPCR and Western blot analyses further indicated that LF-CQPC05 upregulated the mRNA and protein expression levels of lipoprotein lipase (LPL), PPAR-α: peroxisome proliferator-activated receptor-alpha (PPAR-α), (cholesterol 7 alpha-hydroxylase) CYP7A1, and carnitine palmitoyltransferase 1 (CPT1A), and downregulated the expression levels of peroxisome proliferator-activated receptor-gamma (PPAR-γ) and CCAAT enhancer-binding protein alpha (C/EBP-α) in both liver tissue and epididymal adipose tissue. Taken altogether, this study reveals that LF-CQPC05 can effectively inhibit high-fat diet-induced obesity. Its anti-obesity effect is comparable to that of l-carnitine, and is superior to that of Lactobacillus delbrueckii subsp. bulgaricus, a common strain used in the dairy industry. Therefore, LF-CQPC05 is a high-quality microbial strain with probiotic potential.

The Foodborne Strain Lactobacillus fermentum MBC2 Triggers pept-1-Dependent Pro-Longevity Effects in Caenorhabditis elegans

Lactic acid bacteria (LAB) are involved in several food fermentations and many of them provide strain-specific health benefits. Herein, the probiotic potential of the foodborne strain Lactobacillus fermentum MBC2 was investigated through in vitro and in vivo approaches. Caenorhabditis elegans was used as an in vivo model to analyze pro-longevity and anti-aging effects. L. fermentum MBC2 showed a high gut colonization capability compared to E. coli OP50 (OP50) or L.rhamnosus GG (LGG). Moreover, analysis of pumping rate, lipofuscin accumulation, and body bending showed anti-aging effects in L. fermentum MBC2-fed worms. Studies on PEPT-1 mutants demonstrated that pept-1 gene was involved in the anti-aging processes mediated by this bacterial strain through DAF-16, whereas the oxidative stress protection was PEPT-1 independent. Moreover, analysis of acid tolerance, bile tolerance, and antibiotic susceptibility were evaluated. L. fermentum MBC2 exerted beneficial effects on nematode lifespan, influencing energy metabolism and oxidative stress resistance, resulted in being tolerant to acidic pH and able to adhere to Caco-2 cells. Overall, these findings provide new insight for application of this strain in the food industry as a newly isolated functional starter. Furthermore, these results will also shed light on C. elegans molecular players involved in host-microbe interactions.

Regulation, Communication, and Functional Roles of Adipose Tissue-Resident CD4+ T Cells in the Control of Metabolic Homeostasis

Evidence accumulated over the past few years has documented a critical role for adipose tissue (AT)-resident immune cells in the regulation of local and systemic metabolic homeostasis. In the lean state, visceral adipose tissue (VAT) is predominated by anti-inflammatory T-helper 2 (Th2) and regulatory T (Treg) cell subsets. As obesity progresses, the population of Th2 and Treg cells decreases while that of the T-helper 1 (Th1) and T-helper 17 (Th17) cells increases, leading to augmented inflammation and insulin resistance. Notably, recent studies also suggest a potential role of CD4⁺ T cells in the control of thermogenesis and energy homeostasis. In this review, we have summarized recent advances in understanding the characteristics and functional roles of AT CD4⁺ T cell subsets during obesity and energy expenditure. We have also discussed new findings on the crosstalk between CD4⁺ T cells and local antigen-presenting cells (APCs) including adipocytes, macrophages, and dendritic cells (DCs) to regulate AT function and metabolic homeostasis. Finally, we have highlighted the therapeutic potential of targeting CD4⁺ T cells as an effective strategy for the treatment of obesity and its associated metabolic diseases.

Association study of gut flora in Wilson's disease through high-throughput sequencing

In this study, we analyzed the difference of intestinal flora polymorphisms between Wilson's disease (WD) patients and healthy people by high-throughput sequencing technology, and explored the correlation between WD and intestinal flora polymorphism.A total of 22 cases of WD patients and 22 healthy persons as control were recruited. The total DNA was extracted from the fecal specimens of all the subjects, V4 high variable region of 16S rRNA gene was amplified and sequenced by high-throughput sequencing. The sequencing results were analyzed by α diversity and β diversity. The unweighted UniFrac distance matrices were calculated and trees were built by unweighted-pair group method with arithmetic mean (UPGMA).A total of 2,548,262 sequences were obtained after the data are optimized, the average sequences in the WD group was 36,836 ± 4104 and it was 35,051 ± 3075 in the normal control group, there was no significant difference in the average sequence number between the 2 groups. OTU analysis showed that 2663 OTU were obtained in WD group, and 3271 OTU were obtained in the control group, of which 941 were common OTU. Colony diversity analysis showed that the intestinal flora of WD group and control group belonged to 5 phyla, they were Bacteroidetes, Firmicutes, Proteobacteria, Fusobacteria, and Tenericutes, respectively. In WD group, the abundance of Bacteroidetes was significantly lower than that of the control group (67.19% vs 76.75%, P < .001), and the abundance of Firmicutes (26.18% vs 19.83%, P < .001), Proteobacteria (4.31% vs 3.09%, P < .05), Fusobacteria (1.88% vs 0.04%, P < .001) were significantly higher than that of control group. Compared with the control group at the level of the genus, the abundance of Bacteroides (4.85% vs 4.6%, P < .05), Faecalibacterium (2.92% vs 2.13%, P < .05), Megamonas (0.84% vs 0.22%, P < .001), Lachnospira (0.16% vs 0.09%, P < .001) significantly increased in WD group, while the abundance of Prevotella (1.63% vs 2.48%, P < .001), Roseburia (0.75% vs 1.39%, P < .001) and Phascolarctobacterium (1.72% vs 2.45%, P < .001) significantly decreased in WD group. PCoA and UPGMA tree analysis showed that there were significant differences of gut microbial compositions between the 2 groups.The diversity and composition of intestinal flora in the WD patients were significantly lower than those in the healthy controls, and the diversity of intestinal flora may be associated with the presence of WD.

In Vitro and in Vivo Selection of Potentially Probiotic Lactobacilli From Nocellara del Belice Table Olives

Table olives are increasingly recognized as a vehicle as well as a source of probiotic bacteria, especially those fermented with traditional procedures based on the activity of indigenous microbial consortia, originating from local environments. In the present study, we report characterization at the species level of 49 Lactic Acid Bacteria (LAB) strains deriving from Nocellara del Belice table olives fermented with the Spanish or Castelvetrano methods, recently isolated in our previous work. Ribosomal 16S DNA analysis allowed identification of 4 Enterococcus gallinarum, 3 E. casseliflavus, 14 Leuconostoc mesenteroides, 19 Lactobacillus pentosus, 7 L. coryniformis, and 2 L. oligofermentans. The L. pentosus and L. coryniformis strains were subjected to further screening to evaluate their probiotic potential, using a combination of in vitro and in vivo approaches. The majority of them showed high survival rates under in vitro simulated gastro-intestinal conditions, and positive antimicrobial activity against Salmonella enterica serovar Typhimurium, Listeria monocytogenes and enterotoxigenic Escherichia coli (ETEC) pathogens. Evaluation of antibiotic resistance to ampicillin, tetracycline, chloramphenicol, or erythromycin was also performed for all selected strains. Three L. coryniformis strains were selected as very good performers in the initial in vitro testing screens, they were antibiotic susceptible, as well as capable of inhibiting pathogen growth in vitro. Parallel screening employing the simplified model organism Caenorhabditis elegans, fed the Lactobacillus strains as a food source, revealed that one L. pentosus and one L. coryniformis strains significantly induced prolongevity effects and protection from pathogen-mediated infection. Moreover, both strains displayed adhesion to human intestinal epithelial Caco-2 cells and were able to outcompete foodborne pathogens for cell adhesion. Overall, these results are suggestive of beneficial features for novel LAB strains, which renders them promising candidates as starters for the manufacturing of fermented table olives with probiotic added value.

Influence of diet and dietary nanoparticles on gut dysbiosis

Human gut comprises of a huge mixture of microorganisms as they had co-existed for millions of years. The change in co-existence of microbial genera leads to dysbiosis, which creates several disorders in humans. Diet and diet associated agents can have a considerable influence on host health by regulating the gut microbiome, which can thereby maintain the homeostasis of the gut. Analysis of the gut microbiome and the agents that can have an influence on the gut need a profound understanding, which is the need of the hour. The current review therefore focuses on the influence of diet and dietary nanoparticles on the gut microbiota and their positive or adverse effect.