Effects of long-term intake of a yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 on mice

Lactococcus G423 improve growth performance and lipid metabolism of broilers through modulating the gut microbiota and metabolites

This study aimed to explore whether Lactococcus G423 could improve growth performance and lipid metabolism of broilers by the modulation of gut microbiota and metabolites. A total of 640 1-day-old AA broilers were randomly divided into 4 groups [Control (CON), Lac_L, Lac_H, and ABX]. Average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), breast muscle, thigh muscle, and abdominal fat pad were removed and weighed at 42 days of age. Serum was obtained by centrifuging blood sample from jugular vein (10 mL) for determining high-density lipoprotein (HDL), total cholesterol (TC), low-density lipoprotein (LDL), and triglyceride (TG) using ELISA. The ileal contents were harvested and immediately frozen in liquid nitrogen for 16S rRNA and LC-MS analyses. Then, the results of 16S rRNA analysis were confirmed by quantitative polymerase chain reaction (qPCR). Compared with the CON group, FCR significantly decreased in the Lac_H group (p < 0.05) in 1-21 days; ADG significantly increased and FCR significantly decreased in the Lac_H group (p < 0.05) in 22-42 days. 42 days weight body and ADG significantly increased in the Lac_H group (p < 0.05) in 42 days. Abdominal fat percentage was significantly decreased by Lactococcus G423 (p < 0.05), the high dose of Lactococcus G423 significantly decreased the serum of TG, TC, and LDL level (p < 0.05), and the low dose of Lactococcus G423 significantly decreased the serum of TG and TC level (p < 0.05). A significant difference in microbial diversity was found among the four groups. Compared with the CON group, the abundance rates of Firmicutes and Lactobacillus in the Lac_H group were significantly increased (p < 0.05). The global and overview maps and membrane transport in the Lac_L, Lac_H, and ABX groups significantly changed versus those in the CON group (p < 0.05). The results of LC-MS demonstrated that Lactococcus could significantly improve the levels of some metabolites (6-hydroxy-5-methoxyindole glucuronide, 9,10-DiHOME, N-Acetyl-l-phenylalanine, and kynurenine), and these metabolites were involved in four metabolic pathways. Among them, the pathways of linoleic acid metabolism, phenylalanine metabolism, and pentose and glucuronate interconversions significantly changed (p < 0.05). Lactococcus G423 could ameliorate growth performance and lipid metabolism of broilers by the modulation of gut microbiota and metabolites.

Ingesting probiotic yogurt containing Lactiplantibacillus plantarum OLL2712 improves glycaemic control in adults with prediabetes in a randomized, double-blind, placebo-controlled trial

AIM

The ingestion of Lactiplantibacillus plantarum OLL2712 (OLL2712) cells has been shown to improve glucose metabolism by suppressing chronic inflammation in murine models and clinical studies. This study aimed to clarify the effect of OLL2712 on glycaemic control in healthy adults with prediabetes.

MATERIALS AND METHODS

The study was a randomized, double-blind, placebo-controlled, parallel-group design. Adult participants with prediabetes [n = 148, glycated haemoglobin (HbA1c) range: 5.6%-6.4%, age range: 20-64 years] were assigned randomly to placebo or OLL2712 groups (n = 74/group) and administered daily for 12 weeks either conventional yogurt or yogurt containing >5 × 109 heat-treated OLL2712 cells, respectively. In addition, the participants were followed for 8 weeks after the discontinuation of either yogurt. The primary outcome was the changes in HbA1c levels at weeks 12 and 16 by analysis of covariance.

RESULTS

The levels of HbA1c and glycoalbumin decreased significantly in both groups at week 12 in comparison with those at week 0, but only in the OLL2712 group at week 16. HbA1c levels decreased significantly at weeks 12 and 16 in the OLL2712 group in comparison with the placebo group (p = .014 and p = .006, respectively). No significant inter- and intragroup differences in HbA1c levels were observed at week 20.

CONCLUSIONS

The ingestion of OLL2712 prevents the deterioration of glycaemic control and maintains the HbA1c levels within the normal range in adults with prediabetes; yogurt probably exhibits similar effects, which may contribute to reducing the risk of developing type 2 diabetes.

Milk: A Natural Guardian for the Gut Barrier

The gut barrier plays an important role in health maintenance by preventing the invasion of dietary pathogens and toxins. Disruption of the gut barrier can cause severe intestinal inflammation. As a natural source, milk is enriched with many active constituents that contribute to numerous beneficial functions, including immune regulation. These components collectively serve as a shield for the gut barrier, protecting against various threats such as biological, chemical, mechanical, and immunological threats. This comprehensive review delves into the active ingredients in milk, encompassing casein, α-lactalbumin, β-lactoglobulin, lactoferrin, the milk fat globular membrane, lactose, transforming growth factor, and glycopeptides. The primary focus is to elucidate their impact on the integrity and function of the gut barrier. Furthermore, the implications of different processing methods of dairy products on the gut barrier protection are discussed. In conclusion, this study aimed to underscore the vital role of milk and dairy products in sustaining gut barrier health, potentially contributing to broader perspectives in nutritional sciences and public health.

Genetic diversity and phylogenetic relationships of Streptococcus thermophilus isolates from traditional Turkish yogurt: multilocus sequence typing (MLST)

Yogurt, a globally consumed fermented dairy product, is recognized for its taste and potential health benefits attributed to probiotic bacteria, particularly Streptococcus thermophilus. In this study, we employed Multilocus Sequence Typing (MLST) to investigate the genetic diversity and phylogenetic relationships of 13 S. thermophilus isolates from traditional Turkish yogurt samples. We also assessed potential correlations between genetic traits and geographic origins. The isolates were identified as S. thermophilus using VITEK® MALDI-TOF MS, ribotyping, and 16S rRNA analysis methods. MLST analysis revealed 13 different sequence types (STs), with seven new STs for Turkey. The most prevalent STs were ST/83 (n = 3), ST/135 (n = 2), and ST/134 (n = 2). eBURST analysis showed that these isolates mainly were singletons (n = 7) defined as sequence types (STs) that cannot be assigned to any group and differ at two or more alleles from every other ST in the sample. This information suggests that the isolates under study were genetically distinct from the other isolates in the dataset, highlighting their unique genetic profiles within the population. Genetic diversity analysis of ten housekeeping genes revealed polymorphism, with some genes showing higher allelic variation than others. Tajima's D values suggested that selection pressures differed among these genes, with some being more conserved, likely due to their vital functions. Phylogenetic analysis revealed distinct genetic diversity between Turkish isolates and European and Asian counterparts. These findings demonstrate the genetic diversity of S. thermophilus isolates in Turkish yogurt and highlight their unique evolutionary patterns. This research contributes to our understanding of local microbial diversity associated with yogurt production in Turkey and holds the potential for identifyic strains with enhanced functional attributes.

Interleukin-22 enhanced the mucosal barrier and inhibited the invasion of Salmonella enterica in human-induced pluripotent stem cell-derived small intestinal epithelial cells

Human-induced pluripotent stem cell-derived small intestinal epithelial cell (hiPSC-SIEC) monolayers are useful in vitro models for evaluating the gut mucosal barrier; however, their reactivity to cytokines, which are closely related to the regulation of mucosal barrier function, remains unclear. Interleukin (IL)-22 is a cytokine that contributes to regulate the mucosal barrier in the intestinal epithelia. Using microarray and gene set enrichment analysis, we found that hiPSC-SIEC monolayers activate the immune response and enhance the mucosal barrier in response to IL-22. Moreover, hiPSC-SIEC monolayers induced the gene expression of antimicrobials, including the regenerating islet-derived protein 3 family. Furthermore, IL-22 stimulation upregulated Mucin 2 secretion and gene expression of an enzyme that modifies sugar chains, suggesting alteration of the state of the mucus layer of hiPSC-SIEC monolayers. To evaluate its physiological significance, we measured the protective activity against Salmonella enterica subsp. enterica infection in hiPSC-SIEC monolayers and found that prestimulation with IL-22 reduced the number of viable intracellular bacteria. Collectively, these results suggest that hiPSC-SIEC monolayers enhance the mucosal barrier and inhibit infection by pathogenic bacteria in response to IL-22, as previously reported. These results can contribute to the further application of hiPSC-SIECs in evaluating mucosal barriers.

Yogurt starter strains ameliorate intestinal barrier dysfunction via activating AMPK in Caco-2 cells

Lactic acid bacteria (LAB) are commonly used probiotics that improve human health in various aspects. We previously reported that yogurt starter strains, Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131, potentially enhance the intestinal epithelial barrier function by inducing the expression of antimicrobial peptides in the small intestine. However, their effects on physical barrier functions remain unknown. In this study, we found that both strains ameliorated the decreased trans-epithelial resistance and the increased permeability of fluorescein isothiocyanate-dextran induced by tumor necrosis factor (TNF)-α and interferon (IFN)-γ in Caco-2 cells. We also demonstrated that LAB prevented a decrease in the expression and disassembly of tight junctions (TJs) induced by TNF-α and IFN-γ. To assess the repair activity of TJs, a calcium switch assay was performed. Both strains were found to promote the reassembly of TJs, and their activity was canceled by the inhibitor of AMP-activated protein kinase (AMPK). Moreover, these strains showed increased AMPK phosphorylation. These observations suggest that the strains ameliorated physical barrier dysfunction via the activation of AMPK. The activities preventing barrier destruction induced by TNF-α and IFN-γ were strain-dependent. Several strains containing L. bulgaricus 2038 and S. thermophilus 1131 significantly suppressed the barrier impairment, and L. bulgaricus 2038 showed the strongest activity among them. Our findings suggest that the intake of L. bulgaricus 2038 and S. thermophilus 1131 is a potential strategy for the prevention and repair of leaky gut.

MBROLE3: improved functional enrichment of chemical compounds for metabolomics data analysis

MBROLE (Metabolites Biological Role) facilitates the biological interpretation of metabolomics experiments. It performs enrichment analysis of a set of chemical compounds through statistical analysis of annotations from several databases. The original MBROLE server was released in 2011 and, since then, different groups worldwide have used it to analyze metabolomics experiments from a variety of organisms. Here we present the latest version of the system, MBROLE3, accessible at http://csbg.cnb.csic.es/mbrole3. This new version contains updated annotations from previously included databases as well as a wide variety of new functional annotations, such as additional pathway databases and Gene Ontology terms. Of special relevance is the inclusion of a new category of annotations, 'indirect annotations', extracted from the scientific literature and from curated chemical-protein associations. The latter allows to analyze enriched annotations of the proteins known to interact with the set of chemical compounds of interest. Results are provided in the form of interactive tables, formatted data to download, and graphical plots.

Impacts of sodium butyrate on intestinal mucosal barrier and intestinal microbial community in a weaned piglet model

Objective

Butyrate is thought to enhance intestinal mucosal homeostasis, but the detailed mechanism remains unclear. Therefore, further investigation on the mechanism of butyrate regulation of intestinal mucosal homeostasis was performed.

Materials and methods

This study used weaned piglets with similar intestinal metabolic function to humans as a research model. The dietary supplemented 0.2% sodium butyrate group (0.2% S) and negative control group (CON) were established to detect the effects of butyrate on growth performance, intestinal tissue morphology, mucosal barrier function, and intestinal microbial community structure in weaned piglets.

Results

There was an increase in average daily gain (ADG) during three different experimental periods and a reduction in average daily feed intake (ADFI) and feed-to-gain ratio (F:G) during days 1-35 and days 15-35 in 0.2% S compared with CON (P > 0.05). Furthermore, villus height in the ileum and duodenum was increased, and crypt depths in the colon and jejunum were reduced in both groups (P < 0.05). Moreover, the ratio of villus height and crypt depth (V/C) in 0.2% S both in the ileum and jejunum was significantly increased (P < 0.05) compared with CON. The relative mRNA expression of PKC, MUC1, CLDN1, and ITGB1 was upregulated in the ileum of 0.2% S compared with CON (P < 0.05). The digesta samples of 0.2% S, both in the ileum (P < 0.05) and colon, contained greater intestinal bacterial abundance and diversity of probiotics, including Lactobacillus, Streptococcus, Megasphaera, and Blautia, which promoted amino acid metabolism and energy production and conversion in the colon and the synthesis of carbon-containing biomolecules in the ileum.

Conclusion

In summary, dietary supplementation with 0.2% sodium butyrate was shown to have a tendency to improve the growth performance of weaned piglets and enhance intestinal mucosal barrier function via altering the gut microbiota.

Yogurt Benefits Bone Mineralization in Ovariectomized Rats with Concomitant Modulation of the Gut Microbiome

SCOPE

Evidence supports that gut-modulating foods potentially can suppress bone loss in postmenopausal women. This study aims to investigate the effect of milk calcium-enriched milk, yogurt, and yogurt-inulin combination on the gut-bone association.

METHODS AND RESULTS

A 6-week intervention study is conducted in ovariectomized rats. Four pastes containing milk calcium-fortified milk (M-Ca), milk calcium-fortified yogurt (Y-Ca), inulin-fortified Y-Ca (Y-I-Ca), or an isoconcentration of calcium carbonate (Ca-N), and a calcium-deficient paste are provided. M-Ca does not influence bone mineral density and content (BMD and BMC), femur mechanical strength, or femoral microstructure compared to Ca-N, but Y-Ca increases spine BMD. The serum metabolome reveals that Y-Ca modulated glycine-related pathways with reduced glycine, serine, and threonine. No additive effects of yogurt and inulin are found on bone parameters. Correlation analysis shows that increased lactobacilli and reduced Clostridiaceae members in Y-Ca is associated with an increased spine BMD. Increases in Bifidobacterium pseudolongum, Turicibacter, Blautia, and Allobaculum and gut short-chain fatty acids in Y-I-Ca are not reflected in bone parameters.

CONCLUSION

Yogurt as calcium vehicle contributes to increased spine BMD concomitant with changes in the gut microbiome and glycine-related pathways, while adding inulin to yogurt does not affect bone mineralization in ovariectomized rats.

Genomic Characterization of Lactobacillus delbrueckii Strains with Probiotics Properties

Probiotics are health-beneficial microorganisms with mainly immunomodulatory and anti-inflammatory properties. Lactobacillus delbrueckii species is a common bacteria used in the dairy industry, and their benefits to hosting health have been reported. This study analyzed the core genome of nine strains of L. delbrueckii species with documented probiotic properties, focusing on genes related to their host health benefits. For this, a combined methodology including several software and databases (BPGA, SPAAN, BAGEL4, BioCyc, KEEG, and InterSPPI) was used to predict the most important characteristics related to L. delbrueckii strains probiose. Comparative genomics analyses revealed that L. delbrueckii probiotic strains shared essential genes related to acid and bile stress response and antimicrobial activity. Other standard features shared by these strains are surface layer proteins and extracellular proteins-encoding genes, with high adhesion profiles that interacted with human proteins of the inflammatory signaling pathways (TLR2/4-MAPK, TLR2/4-NF-κB, and NOD-like receptors). Among these, the PrtB serine protease appears to be a strong candidate responsible for the anti-inflammatory properties reported for these strains. Furthermore, genes with high proteolytic and metabolic activity able to produce beneficial metabolites, such as acetate, bioactive peptides, and B-complex vitamins were also identified. These findings suggest that these proteins can be essential in biological mechanisms related to probiotics’ beneficial effects of these strains in the host.

Acids produced by lactobacilli inhibit the growth of commensal Lachnospiraceae and S24-7 bacteria

The Lactobacillaceae are an intensively studied family of bacteria widely used in fermented food and probiotics, and many are native to the gut and vaginal microbiota of humans and other animals. Various studies have shown that specific Lactobacillaceae species produce metabolites that can inhibit the colonization of fungal and bacterial pathogens, but less is known about how Lactobacillaceae affect individual bacterial species in the endogenous animal microbiota. Here, we show that numerous Lactobacillaceae species inhibit the growth of the Lachnospiraceae family and the S24-7 group, two dominant clades of bacteria within the gut. We demonstrate that inhibitory activity is a property common to homofermentative Lactobacillaceae species, but not to species that use heterofermentative metabolism. We observe that homofermentative Lactobacillaceae species robustly acidify their environment, and that acidification alone is sufficient to inhibit growth of Lachnospiraceae and S24-7 growth, but not related species from the Clostridiales or Bacteroidales orders. This study represents one of the first in-depth explorations of the dynamic between Lactobacillaceae species and commensal intestinal bacteria, and contributes valuable insight toward deconvoluting their interactions within the gut microbial ecosystem.

The genomic basis of the Streptococcus thermophilus health-promoting properties

Background

Streptococcus thermophilus is a Gram-positive bacterium widely used as starter in the dairy industry as well as in many traditional fermented products. In addition to its technological importance, it has also gained interest in recent years as beneficial bacterium due to human health-promoting functionalities. The objective of this study was to inventory the main health-promoting properties of S. thermophilus and to study their intra-species diversity at the genomic and genetic level within a collection of representative strains.

Results

In this study various health-related functions were analyzed at the genome level from 79 genome sequences of strains isolated over a long time period from diverse products and different geographic locations. While some functions are widely conserved among isolates (e.g., degradation of lactose, folate production) suggesting their central physiological and ecological role for the species, others including the tagatose-6-phosphate pathway involved in the catabolism of galactose, and the production of bioactive peptides and gamma-aminobutyric acid are strain-specific. Most of these strain-specific health-promoting properties seems to have been acquired via horizontal gene transfer events. The genetic basis for the phenotypic diversity between strains for some health related traits have also been investigated. For instance, substitutions in the galK promoter region correlate with the ability of some strains to catabolize galactose via the Leloir pathway. Finally, the low occurrence in S. thermophilus genomes of genes coding for biogenic amine production and antibiotic resistance is also a contributing factor to its safety status.

Conclusions

The natural intra-species diversity of S. thermophilus, therefore, represents an interesting source for innovation in the field of fermented products enriched for healthy components that can be exploited to improve human health. A better knowledge of the health-promoting properties and their genomic and genetic diversity within the species may facilitate the selection and application of strains for specific biotechnological and human health-promoting purpose. Moreover, by pointing out that a substantial part of its functional potential still defies us, our work opens the way to uncover additional health-related functions through the intra-species diversity exploration of S. thermophilus by comparative genomics approaches.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08459-y.

Identification of Potential Biomarkers of Type 2 Diabetes Mellitus-Related Immune Infiltration Using Weighted Gene Coexpression Network Analysis

Background

Type 2 diabetes mellitus (T2DM) is characterized by chronic low-grade inflammation, showing an increasing trend. The infiltration of immune cells into adipose tissue has been shown to be an important pathogenic cause of T2DM. The purpose of this study is to use the relevant database to identify some abnormally expressed or dysfunctional genes related to diabetes from the perspective of immune infiltration.

Methods

Weighted gene coexpression network analysis (WGCNA) was employed to systematically identify the coexpressed gene modules and hub genes associated with T2DM development based on a microarray dataset (GSE23561) from the Gene Expression Omnibus (GEO) database. The key genes in modules highly related to clinical features were calculated and screened by using R software, and their participation in T2DM was determined by gene enrichment analysis. The mRNA levels of CSF1R, H2AFV, LCK, and TLR9 in pre-T2DM mice and normal wild-type mice were detected by WGCNA screening and real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR).

Results

We constructed 14 coexpressed gene modules, and the brown module was shown to be significantly related to T2DM. Through verification of the protein-protein interaction (PPI) network, four upregulated hub genes, CSF1R, H2AFV, LCK, and TLR9, were screened from the brown module and successfully distinguishedT2DM patients from healthy people. These hub genes may be used as biomarkers and important indicators for patient diagnosis. Enrichment analysis showed that these hub genes were highly associated with IL-6-related inflammatory metabolism, immune regulation, and immune cell infiltration. Finally, we verified the hub genes CSF1R, LCK, and TLR9 in a T2DM animal model and found that their mRNA levels were significantly higher in animals with T2DM than in control group mice (NC).

Conclusions

In summary, our results suggest that these hub genes (CSF1R, LCK, and TLR9) can serve as biomarkers and immunotherapeutic targets for T2DM.

Ovariectomy-Induced Dysbiosis May Have a Minor Effect on Bone in Mice

We determined the bone mineral density (BMD) and the expression of serum bone formation marker (procollagen type I N-terminal propeptide: PINP) and bone resorption marker (C-terminal telopeptide of collagen: CTX) by ELISA to evaluate ovariectomy-induced osteoporosis in ovariectomized (OVX) mice. The intestinal microbiota of the mice was assessed using 16S rRNA gene sequencing. OVX mice exhibited a lower BMD of 87% with higher serum levels of CTX and PINP compared to sham-operated (sham) mice. The cecum microbiome of OVX mice showed lower bacterial diversity than that of sham mice. TNFα mRNA levels in the colon were 1.6 times higher, and zonula occludens-1 mRNA and protein expression were lower in OVX mice than in sham mice, suggesting that ovariectomy induced inflammation and increased intestinal permeability. Next, we used antibiotic treatment followed by fecal microbiota transplantation (FMT) to remodel the gut microbiota in the OVX mice. A decrease in PINP was observed in antibiotic-treated mice, while there was no change in BMD or CTX between mice with and without antibiotic treatment. Oral transplantation of the luminal cecal content of OVX or sham mice to antibiotic-treated mice did not affect the BMD or PINP and CTX expression. Additionally, transplantation of the luminal contents of OVX or sham mice to antibiotic-treated OVX mice had similar effects on BMD, PINP, and CTX. In conclusion, although ovariectomy induces dysbiosis in the colon, the changes in the gut microbiota may only have a minor role in ovariectomy-induced osteoporosis.

Microbiota Targeted Interventions of Probiotic Lactobacillus as an Anti-Ageing Approach: A Review

With the implementation of modern scientific protocols, the average human lifespan has significantly improved, but age-related problems remain a challenge. With the advent of ageing, there are alterations in gut microbiota and gut barrier functions, weak immune responses, increased oxidative stress, and other age-related disorders. This review has highlighted and discussed the current understanding on the significance of gut microbiota dysbiosis and ageing and its inherent effects against age-related oxidative stress as well as on the gut health and gut-brain axis. Further, we have discussed the key mechanism of action of Lactobacillus strains in the longevity of life, alleviating gut dysbiosis, and improving oxidative stress and inflammation to provide an outline of the role of Lactobacillus strains in restoration of gut microbiota dysbiosis and alleviating certain conditions during ageing. Microbiota-targeted interventions of some characterized strains of probiotic Lactobacillus for the restoration of gut microbial community are considered as a potential approach to improve several neurological conditions. However, very limited human studies are available on this alarmed issue and recommend further studies to identify the unique Lactobacillus strains with potential anti-ageing properties and to discover its novel core microbiome-association, which will help to increase the therapeutic potential of probiotic Lactobacillus strains to ageing.

Safety and efficacy of using heat-killed Lactobacillus plantarum L-137: High-dose and long-term use effects on immune-related safety and intestinal bacterial flora

Heat-killed Lactobacillus plantarum L-137 (HK L-137) promotes immune function in animals. In healthy people, T-cell proliferation was shown to be enhanced by taking 10 mg HK L-137 daily for 12 weeks. However, the safety and efficacy of higher doses or longer treatments have not yet been investigated in humans. To investigate the high-dose and long-term use effects of HK L-137 on immune-related safety and on host intestinal bacterial flora, 15 healthy volunteers took a daily HK L-137 (50 mg) preparation for 4 weeks. An additional 29 participants who regularly visited a clinic for health care took HK L-137 (10 mg) daily for 12 months. Measures for anthropometrics, hematology, biochemistry, and urinalysis were taken at scheduled timepoints for all participants. Stool and blood samples were also collected and evaluated for microbes and short-chain fatty acids (SCFA); isolated T-cells were assessed for levels of proliferation induced by phytohemagglutinin in the long-term study. Adverse events or shifts in clinical measures from normal ranges due to the dietary intervention were not observed in the high-dose or long-term studies. Long-term intake also did not result in immune exhaustion due to any chronic immunostimulation; ex vivo T-cell proliferation was significantly greater at 12 months than at baseline (p < 0.01). In addition, the Firmicutes/Bacteroidetes ratio in stool samples was significantly lower at 12 months than at baseline (p < 0.05) due to the long-term intake of the HK L-137. Lastly, fecal SCFA concentrations were significantly greater (p < 0.05) at 6 months than at baseline. From these data, it can be concluded that the efficacy of HK L-137 is maintained with no overt adverse effects as a result of high-dose and/or long-term consumption.

Dairy consumption and hepatocellular carcinoma risk

This review provides epidemiological and translational evidence for milk and dairy intake as critical risk factors in the pathogenesis of hepatocellular carcinoma (HCC). Large epidemiological studies in the United States and Europe identified total dairy, milk and butter intake with the exception of yogurt as independent risk factors of HCC. Enhanced activity of mechanistic target of rapamycin complex 1 (mTORC1) is a hallmark of HCC promoted by hepatitis B virus (HBV) and hepatitis C virus (HCV). mTORC1 is also activated by milk protein-induced synthesis of hepatic insulin-like growth factor 1 (IGF-1) and branched-chain amino acids (BCAAs), abundant constituents of milk proteins. Over the last decades, annual milk protein-derived BCAA intake increased 3 to 5 times in Western countries. In synergy with HBV- and HCV-induced secretion of hepatocyte-derived exosomes enriched in microRNA-21 (miR-21) and miR-155, exosomes of pasteurized milk as well deliver these oncogenic miRs to the human liver. Thus, milk exosomes operate in a comparable fashion to HBV- or HCV- induced exosomes. Milk-derived miRs synergistically enhance IGF-1-AKT-mTORC1 signaling and promote mTORC1-dependent translation, a meaningful mechanism during the postnatal growth phase, but a long-term adverse effect promoting the development of HCC. Both, dietary BCAA abundance combined with oncogenic milk exosome exposure persistently overstimulate hepatic mTORC1. Chronic alcohol consumption as well as type 2 diabetes mellitus (T2DM), two HCC-related conditions, increase BCAA plasma levels. In HCC, mTORC1 is further hyperactivated due to RAB1 mutations as well as impaired hepatic BCAA catabolism, a metabolic hallmark of T2DM. The potential HCC-preventive effect of yogurt may be caused by lactobacilli-mediated degradation of BCAAs, inhibition of branched-chain α-ketoacid dehydrogenase kinase via production of intestinal medium-chain fatty acids as well as degradation of milk exosomes including their oncogenic miRs. A restriction of total animal protein intake realized by a vegetable-based diet is recommended for the prevention of HCC.

Lactobacillus delbrueckii alleviates depression-like behavior through inhibiting toll-like receptor 4 (TLR4) signaling in mice

Background

The intestinal flora can influence behavior through the microbiota-gut-brain axis and is closely related to the occurrence and development of nervous system diseases such as depression. Probiotics like Lactobacillus may regulate the balance of the intestinal flora and play an active role in preventing and treating depression.

Methods

Eight-week-old C57BL/6J mice (n=32) were randomly and equally divided into a normal control group, a control + Lac group, a model group, and a model + Lac group. The model and model + Lac groups were intraperitoneally injected with 1.2 mg/kg lipopolysaccharide for 7 days, and the behavior of the mice was assessed 24 hours later. The normal and model groups received intragastric administration of saline daily, while the control + Lac and model + Lac groups were given 10⁹ cfu Lac intragastrically daily for 7 days. The inhibitory effect of Lac and its fermentation products on depression-related bacteria were examined in vitro.

Results

Lac effectively inhibited the production of depression-like behaviors in mice. The expression levels of zonula occludens-1 (ZO-1) and E-cadherin in the small intestine in the model group were significantly decreased, but Lac abrogated this effect. Overactivation of microglia and decreased expression of dopamine transporter (DAT) in brain tissues, which are closely related to depression, were also abrogated by Lac treatment. Furthermore, the expression of toll-like receptor 4 (TLR4) and nod-like receptor protein-3 (NLRP3), as well as the level of interleukin-1 beta (IL-1β) in the intestine and brain, were all significantly increased; however, these effects were subsequently abrogated by Lac. Moreover, Lac inhibited dysbiosis through its metabolites.

Conclusions

Lac has a remarkable antidepressant function, which it performs through the inhibition of dysbiosis (via its metabolites) and pattern recognition receptor TLR4 signaling.

Age-specific microbiota in altering host inflammatory and metabolic signaling as well as metabolome based on the sex

Background

Metabolism is sex-different, and the direct link between gut microbiota and aging-associated metabolic changes needs to be established in both sexes.

Methods

Gene expression, metabolic and inflammatory signaling, gut microbiota profile, and metabolome were studied during aging and after fecal microbiota transplantation (FMT) in mice of both sexes.

Results

Our data revealed young female mice and aged male mice were the most insulin sensitive and resistant group, respectively. In addition, aging reduced sex difference in insulin sensitivity. Such age- and sex-dependent metabolic phenotypes were accompanied by shifted gut microbiota profile and altered abundance of bacterial genes that produce butyrate, propionate, and bile acids. After receiving feces from the aged males (AFMT), the most insulin-resistant group, recipients of both sexes had increased hepatic inflammation and serum endotoxin. However, AFMT only increased insulin resistance in female mice and abolished sex difference in insulin sensitivity. Additionally, such changes were accompanied by narrowed sex difference in metabolome. Metabolomics data revealed that age-associated insulin resistance in males was accompanied by increased sugar alcohols and dicarboxylic acids as well as reduced aromatic and branched-chain amino acids. Further, receiving feces from the young females (YFMT), the most insulin-sensitive group, reduced body weight and fasting blood glucose in male recipients and improved insulin sensitivity in females, leading to enhanced sex differences in insulin sensitivity and metabolome.

Conclusions

Aging systemically affected inflammatory and metabolic signaling based on the sex. Gut microbiome is age and sex-specific, which affects inflammation and metabolism in a sex-dependent manner.

Ingesting Yogurt Containing Lactobacillus plantarum OLL2712 Reduces Abdominal Fat Accumulation and Chronic Inflammation in Overweight Adults in a Randomized Placebo-Controlled Trial

BACKGROUND

Chronic inflammation and insulin resistance are factors that are related to obesity. We have suggested that the administration of heat-treated Lactobacillus plantarum OLL2712 (OLL2712) cells can improve glucose and lipid metabolism by suppressing chronic inflammation in mouse models and a preliminary clinical study.

OBJECTIVE

The aim of this study was to investigate whether ingesting OLL2712 cells can reduce body fat accumulation and improve metabolic risk factors, in overweight, healthy adults.

METHODS

This study was a randomized, double-blind, placebo-controlled, parallel-group trial conducted at a single center in Japan. The study participants included 100 overweight (BMI range, ≥25 to <30 kg/m2) adults aged 20-64 y. They were randomly assigned to either the placebo or OLL2712 group (n = 50 each) and were administered conventional yogurt or yogurt containing >5 × 109 heat-treated OLL2712 cells, respectively, daily for 12 wk. The primary outcome was the 12-wk change in the abdominal fat area, as assessed by computed tomography, and the secondary outcomes were glucose and lipid metabolism-related parameters and chronic inflammation markers, which were analyzed using a linear mixed model.

RESULTS

The 12-wk change of abdominal fat area (difference: 8.5 cm2; 95% CI: 0.3, 16.6 cm2; P = 0.040) and fasting plasma glucose (difference: 3.2 mg/dL; 95% CI: 0.8, 5.6 mg/dL; P = 0.021) were significantly less in the OLL2712 group than the placebo group. The overall trend of serum IL-6 was significantly decreased in the OLL2712 group compared with baseline and the placebo group.

CONCLUSIONS

The ingestion of heat-treated OLL2712 cells reduces body fat accumulation and the deterioration of glycemic control and chronic inflammation, in overweight, healthy adults. We hypothesize that OLL2712 cells may prevent obesity by regulating chronic inflammation. This trial was registered at the University Hospital Medical Information Network Clinical Trials Registry as UMIN000027709.

Dietary Montmorillonite Improves the Intestinal Mucosal Barrier and Optimizes the Intestinal Microbial Community of Weaned Piglets

The study investigated the impact of dietary montmorillonite on the growth performance, intestinal mucosal barrier, and microbial community in weaned piglets with control group (CON) and dietary supplementation of 0.2% montmorillonite (0.2% M). Compared with the CON group, 0.2% M feed in the diet increased the average daily gain (ADG) on days 15-35 and day 1-35 and the average daily feed intake on days 1-35 (ADFI) (0.05 < P < 0.1). Besides, higher villus height of the duodenum and jejunum and lower crypt depth of duodenum and colon were revealed in the 0.2% M group than in the CON group (P < 0.05). Moreover, the V/C (ratio of the villus height and crypt depth) in the 0.2% M group was increased compared to that in the CON group both from the duodenum and ileum (P < 0.05). The relative mRNA expression of mucin-1, ITGB1 (β1-integrins), and PKC (protein kinase C) of ileum in the 0.2% M group were upregulated (P < 0.05) compared to that in the CON group. The digesta sample of ileum from piglets in the 0.2% M group contained greater (P < 0.05) intestinal bacterial diversity and abundances of probiotics, such as Streptococcus, Eubacterium_rectale_group, and Lactobacillus, which could promote the synthesis of carbon-containing biomolecules. Overall, dietary supplementation of 0.2% M was shown to have a tendency to improve the growth performance of weaned piglets and may enhance their intestinal mucosal barrier function via altering the gut microbiota.

Proton pump inhibitors enhance intestinal permeability via dysbiosis of gut microbiota under stressed conditions in mice

BACKGROUND

Intestinal permeability and psychological stress are considered the key mechanism(s) in functional dyspepsia (FD). Although proton pump inhibitors (PPIs) are commonly used for the treatment of FD, the effect of PPIs on intestinal permeability has not been elucidated. This study investigated the effect of PPI on intestinal permeability under stressed conditions.

METHODS

C57BL/6J mice were subjected to water avoidance stress (WAS) and administered rabeprazole (40 mg/kg) or vehicle treatment (VT). We then evaluated intestinal permeability both in vivo and ex vivo using plasma fluorescein isothiocyanate-dextran and by assessing the paracellular permeability and transepithelial electrical resistance (TEER) in an Ussing chamber, respectively. Furthermore, we evaluated the effect of PPI-treated fecal microbiota transplant (FMT) on intestinal permeability in vivo. Microbiota profiles of donor feces were assessed by 16S rRNA gene analysis using MiSeq and QIIME2.

KEY RESULTS

In the WAS treatment, PPI significantly enhanced intestinal permeability in vivo compared to that in VT. Moreover, PPI significantly increased paracellular permeability and decreased TEER in the duodenum and jejunum, respectively, compared to those in VT under stressed conditions. Moreover, both vasoactive intestinal peptide (VIP) receptor antagonist and ketotifen significantly reversed the effect of PPI on intestinal permeability. Furthermore, PPI-treated FMT significantly increased the intestinal permeability in vivo compared to that in vehicle-treated FMT. Proton pump inhibitors treatment altered the gut microbiota composition, indicating that PPI induced dysbiosis.

CONCLUSIONS AND INFERENCES

Under stressed conditions, PPI enhances intestinal permeability via dysbiosis of gut microbiota. Vasoactive intestinal peptide and mast cells are also implicated in the underlying mechanisms.

Effects of 12-Week Ingestion of Yogurt Containing Lactobacillus plantarum OLL2712 on Glucose Metabolism and Chronic Inflammation in Prediabetic Adults: A Randomized Placebo-Controlled Trial

The ingestion of Lactobacillus plantarum OLL2712 (OLL2712) cells improved glucose metabolism by suppressing chronic inflammation in mouse models and in a preliminary clinical study. We aimed to clarify the effect of OLL2712 on glucose metabolism and chronic inflammation for healthy adults. Prediabetic adults (n = 130, age range: 20–64 years) were randomly assigned to either the placebo or OLL2712 groups (n = 65 each) and were administered conventional yogurt or yogurt containing more than 5 × 10⁹ heat-treated OLL2712 cells, respectively, daily for 12 weeks. Reduced HbA1c levels after 12 weeks of treatment were observed in both groups compared to those at baseline; however, the 12-week reduction of HbA1c levels was significantly greater in the OLL2712 group than in the placebo group. Increased chronic inflammation marker levels and insulin-resistant index (HOMA-IR) occurred in the placebo group but not in the OLL2712 group. Fasting blood glucose (FBG) levels did not change significantly in both groups; however, in subgroup analyses including participants with higher FBG levels, FBG levels were significantly reduced only in the OLL2712 group compared to baseline. These results suggest that OLL2712 cell ingestion can reduce HbA1c levels and can prevent the aggravation of chronic inflammation and insulin resistance.

Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 Induce the Expression of the REG3 Family in the Small Intestine of Mice via the Stimulation of Dendritic Cells and Type 3 Innate Lymphoid Cells

Accumulating evidence clarifies that intestinal barrier function, for example, by the mucus layer, antimicrobial peptides, immune systems, and epithelial tight junctions, plays crucial roles in maintaining our health. We reported previously that yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 induced the gene expression of the regenerating family member 3 (REG3) family, which encodes antimicrobial peptides in the small intestine, although it was unclear how the yogurt activated the intestinal cells related to it. Here, we evaluated the cytokine production from the intestinal immune cells stimulated by these strains in vitro and in vivo to elucidate the mechanism for the induction of the REG3 family by the yogurt. The results showed that stimulation by both strains induced interleukin (IL)-23 production from bone marrow-derived dendritic cells (DCs) and IL-22 production from small intestinal lamina propria (LP) cells. In addition, oral administration of these strains to mice increased IL-23p19+ LPDCs and IL-22+ type 3 innate lymphoid cells and induced the expression of Reg3g in small intestinal tissue. Moreover, we showed that the activities for the induction of IL-23 by DCs were strain dependent on L. bulgaricus and S. thermophilus and that S. thermophilus 1131, which is the predominant species in the yogurt, exhibited relatively higher activity compared to the other strains of S. thermophilus. Our findings suggested that these yogurt starter strains, L. bulgaricus 2038 and S. thermophilus 1131, have the potential to maintain and improve intestinal barrier function by stimulating immune cells in the LP.

High-fat diet-mediated dysbiosis exacerbates NSAID-induced small intestinal damage through the induction of interleukin-17A

Non-steroidal anti-inflammatory drugs (NSAIDs) cause damage in the small intestine in a bacteria-dependent manner. As high-fat diet (HFD) is a potent inducer of gut dysbiosis, we investigated the effects of HFD on bacterial flora in the small intestine and NSAID-induced enteropathy. 16S rRNA gene analysis revealed that the population of Bifidobacterium spp. significantly decreased by fold change of individual operational taxonomic units in the small intestine of mice fed HFD for 8 weeks. HFD increased intestinal permeability, as indicated by fluorescein isothiocyanate-dextran absorption and serum lipopolysaccharide levels, accompanied by a decrease in the protein expressions of ZO-1 and occludin and elevated mRNA expression of interleukin (IL)-17A in the small intestine. HFD-fed mice exhibited increased susceptibility to indomethacin-induced damage in the small intestine; this phenotype was observed in normal diet-fed mice that received small intestinal microbiota from HFD-fed mice. Administration of neutralizing antibodies against IL-17A to HFD-fed mice reduced intestinal permeability and prevented exacerbation of indomethacin-induced damage. Thus, HFD-induced microbial dysbiosis in small intestine caused microinflammation through the induction of IL-17A and increase in intestinal permeability, resulting in the aggravation of NSAID-induced small intestinal damage.

Diet-Induced Obese Mice and Leptin-Deficient Lepob/ob Mice Exhibit Increased Circulating GIP Levels Produced by Different Mechanisms

As glucose-dependent insulinotropic polypeptide (GIP) possesses pro-adipogenic action, the suppression of the GIP hypersecretion seen in obesity might represent a novel therapeutic approach to the treatment of obesity. However, the mechanism of GIP hypersecretion remains largely unknown. In the present study, we investigated GIP secretion in two mouse models of obesity: High-fat diet-induced obese (DIO) mice and leptin-deficient Lep^ob/ob mice. In DIO mice, plasma GIP was increased along with an increase in GIP mRNA expression in the lower small intestine. Despite the robust alteration in the gut microbiome in DIO mice, co-administration of maltose and the α-glucosidase inhibitor (α-GI) miglitol induced the microbiome-mediated suppression of GIP secretion. The plasma GIP levels of Lep^ob/ob mice were also elevated and were suppressed by fat transplantation. The GIP mRNA expression in fat tissue was not increased in Lep^ob/ob mice, while the expression of an interleukin-1 receptor antagonist (IL-1Ra) was increased. Fat transplantation suppressed the expression of IL-1Ra. The plasma IL-1Ra levels were positively correlated with the plasma GIP levels. Accordingly, although circulating GIP levels are increased in both DIO and Lep^ob/ob mice, the underlying mechanisms differ, and the anti-obesity actions of α-GIs and leptin sensitizers may be mediated partly by the suppression of GIP secretion.

Angiotensin-converting enzyme inhibitory peptides from Lactobacillus delbrueckii QS306 fermented milk

Angiotensin-converting enzyme inhibitory peptides were isolated and identified from milk fermented using Lactobacillus delbrueckii QS306. The peptide with the highest angiotensin-converting enzyme inhibitory activity (C5) was purified using ultrafiltration with 10 and 3 kDa molecular mass cut-off membranes, Sephadex G-15 (Sigma-Aldrich, St. Louis, MO) gel filtration chromatography, reversed-phase HPLC, and Orbitrap Elite (Thermo Fisher Scientific Inc., Waltham, MA) liquid chromatography-tandem mass spectrometry. We obtained peptide LPYPY by microbial fermentation, which was derived from κ-casein f (AA 77-81). We synthesized LPYPY using an Fmoc solid-phase synthesis method and explored the secondary structure of the pentapeptide. The half maximal inhibitory concentration for the angiotensin-converting enzyme inhibitory activity of LPYPY was 12.87 μg/mL. The results provide additional information for ongoing research and the development of functional foods having antihypertensive effects.

In vitro Organic Acid Production and In Vivo Food Pathogen Suppression by Probiotic S. thermophilus and L. bulgaricus

Foodborne pathogens are a major source of morbidity and mortality worldwide. For this cause, exploring various effective ways of suppressing their spread is at the forefront of many research projects. The current study aims to investigate the in vitro organic acid production of S. thermophilus KLDS 3.1003 and L. bulgaricus KLDS 1.0207 strains, their in vivo suppression of and immuno-modulatory effects against E. coli ATCC 25922 and S. aureus ATCC 25923 pathogens. First, lactic and acetic acid production using three carbon sources – 1% glucose (control), 1% sucrose, and 1% fructo-oligosaccharides (FOS) – was determined by HPLC. For the in vivo section, a total of 40 BALB/c mice were purchased and divided into 10 treatment groups (control and nine treatments). Animals were given 1 week to acclimatize and then fed treatment diets for 14 days. Afterward, hematological (RBC, WBC, HB, PLT, Neutrophils, Eosinophils, Lymphocytes, and Monocytes) and histopathological analyses were carried out. All analyses were done in triplicate. Results show that lactic and acetic acid productions for both strains increased with supplementation and were highest after 1% FOS addition. Regardless of carbon source, L. bulgaricus KLDS 1.0207 produced higher (P < 0.05) amounts of lactic and acetic acids than S. thermophilus KLDS 3.1003. Also, generally better hematological parameters in probiotic groups than the control (P < 0.05) were observed. In some instances, mice in probiotic treatment groups had better immunity levels (lymphocytes, monocytes, neutrophils, eosinophils) than those in the control and pathogen groups. Histopathological studies showed that no anomalies were associated with S. thermophilus KLDS 3.1003 and L. bulgaricus KLDS 1.0207 administration. In conclusion, S. thermophilus KLDS 3.1003 and L. bulgaricus KLDS 1.0207 strains are not only probiotic candidates but can have therapeutic applications.

Lactobacillus Dominate in the Intestine of Atlantic Salmon Fed Dietary Probiotics

Probiotics, the live microbial strains incorporated as dietary supplements, are known to provide health benefits to the host. These live microbes manipulate the gut microbial community by suppressing the growth of certain intestinal microbes while enhancing the establishment of some others. Lactic acid bacteria (LAB) have been widely studied as probiotics; in this study we have elucidated the effects of two fish-derived LAB types (RII and RIII) on the distal intestinal microbial communities of Atlantic salmon (Salmo salar). We employed high-throughput 16S rRNA gene amplicon sequencing to investigate the bacterial communities in the distal intestinal content and mucus of Atlantic salmon fed diets coated with the LABs or that did not have microbes included in it. Our results show that the supplementation of the microbes shifts the intestinal microbial profile differentially. LAB supplementation did not cause any significant alterations in the alpha diversity of the intestinal content bacteria but RIII feeding increased the bacterial diversity in the intestinal mucus of the fish. Beta diversity analysis revealed significant differences between the bacterial compositions of the control and LAB-fed groups. Lactobacillus was the dominant genus in LAB-fed fish. A few members of the phyla Tenericutes, Proteobacteria, Actinobacteria, and Spirochaetes were also found to be abundant in the LAB-fed groups. Furthermore, the bacterial association network analysis showed that the co-occurrence pattern of bacteria of the three study groups were different. Dietary probiotics can modulate the composition and interaction of the intestinal microbiota of Atlantic salmon.

Low-fat yogurt alleviates the pro-inflammatory cytokine IL-1β-induced intestinal epithelial barrier dysfunction

Yogurt is a source of bioactive compounds and probiotic microorganisms that modify immunity and metabolism to benefit human health beyond nutrition. In this study, we examined the capacity of yogurt to prevent epithelial barrier disruption in vitro. Different preparations of yogurt were added apically to Caco-2 monolayers before IL-1β exposure. Dulbecco's modified Eagle medium containing 25% (vol/vol) low-fat yogurt prevented cytokine-induced transepithelial resistance reduction and increases to paracellular permeability measured with fluorescein isothiocyanate-dextran (4 kDa), whereas nonfat yogurt was unable to decrease paracellular permeability to fluorescein isothiocyanate-dextran. Moreover, the concentration of IL-8 in low-fat-yogurt-treated inflamed cells was decreased to 252.40 ± 27.24 pg/mL, which was lower than that of untreated, inflamed cells (407.20 ± 50.05 pg/mL), further indicating the anti-inflammatory roles of low-fat yogurt. The low-fat yogurt was able to downregulate the transcription of myosin light-chain kinase (MLCK) gene, but upregulate the expression of tight junction protein ZO-1 (TJP1). These findings indicate that low-fat yogurt can maintain intestinal barrier integrity better than nonfat yogurt after pro-inflammatory cytokine exposure.