Identification of antioxidants produced by Lactobacillus plantarum

Biofunctional attributes and storage study of milk fermented by Enterococcus italicus

Lactic acid bacteria are probiotics in the intestines and have been widely used as natural antioxidants in the food industry. In this study, Enterococcus italicus FM5 with strong antioxidant ability was isolated from fresh milk. The safety evaluation showed that E. italicus FM5 was sensitive to ampicillin, chloramphenicol, erythromycin, vancomycin, rifampicin, and tetracycline, and was not hemolytic. Meanwhile, the whole genome information and biofunctional attributes of this strain were determined and analyzed. Subsequently, E. italicus FM5 was co-cultured with traditional yogurt starters (Streptococcus thermophilus and Lactobacillus bulgaricus) to make fermented milk. The results showed that the addition of E. italicus FM5 could improve the oxygen free radical scavenging ability of the fermented milk, and the scavenging rates of DPPH, ABTS, OH-, and O2- radicals reaching up to 95.54 %, 88.35 %, 93.65 %, and 60.29 %, respectively. Furthermore, the addition of E. italicus FM5 reduced the curd time and improved the water holding capacity of the fermented milk. Besides, the growth of Lb. bulgaricus was significantly promoted when co-cultured with E. italicus FM5, thus the survival cells were increased compared with the traditional fermentation processes. Therefore, this study emphasized the potential to manufacture fermented milk by the co-cultivation of E. italicus with traditional yogurt starters.

Microbial aromatic amino acid metabolism is modifiable in fermented food matrices to promote bioactivity

Ingestion of fermented foods impacts human immune function, yet the bioactive food components underlying these effects are not understood. Here, we interrogated whether fermented food bioactivity relates to microbial metabolites derived from aromatic amino acids, termed aryl-lactates. Using targeted metabolomics, we established the presence of aryl-lactates in commercially available fermented foods. After pinpointing fermented food-associated lactic acid bacteria that produce high levels of aryl-lactates, we identified fermentation conditions to increase aryl-lactate production in food matrices up to 5 × 103 fold vs. standard fermentation conditions. Using ex vivo reporter assays, we found that food matrix conditions optimized for aryl-lactate production exhibited enhanced agonist activity for the human aryl-hydrocarbon receptor (AhR) as compared to standard fermentation conditions and commercial products. Reduced microbial-induced AhR activity has emerged as a hallmark of many chronic inflammatory diseases, thus we envision strategies to enhance AhR bioactivity of fermented foods to be leveraged to improve human health.

Indole-3-Lactic Acid Derived from Lacticaseibacillus paracasei Inhibits Helicobacter pylori Infection via Destruction of Bacteria Cells, Protection of Gastric Mucosa Epithelial Cells, and Alleviation of Inflammation

Indole-3-lactic acid (ILA) has exhibited antimicrobial properties. However, its role in inhibiting Helicobacter pylori infection remains elusive. This study investigated the inhibitory effect of ILA produced by Lacticaseibacillus paracasei on H. pylori, which was further confirmed by cell and animal experiments. 5 mg/mL ILA was sufficient to directly inhibit the growth of H. pylori in vitro, with a urease inhibitory activity reaching 60.94 ± 1.03%, and the cell morphology and structure were destroyed. ILA inhibited 56.5% adhesion of H. pylori to GES-1 and significantly reduced the number of apoptotic cells. Furthermore, ILA suppresses H. pylori colonization by approximately 38% to 63%, reduced inflammation and oxidative stress in H. pylori-infected mice, and enhanced the enrichment and variety of gut microbiota, notably fostering the growth of beneficial bacteria such as Lactobacillus and Bifidobacterium strains. The results support that ILA derived from Lactobacillus can be applicated as a novel prebiotic in anti-H. pylori functional foods.

Exploring the Biogenic Transformation Mechanism of Polyphenols by Lactobacillus plantarum NCU137 Fermentation and Its Enhancement of Antioxidant Properties in Wolfberry Juice

This study investigated the transformation of polyphenols, including free and bound polyphenols during the fermentation of wolfberry juice by Lactobacillus plantarum NCU137. Results indicated that fermentation significantly increased the free polyphenols content and released bound polyphenols, enhancing the antioxidant activity. Analysis showed that there were 19 free polyphenols, mainly scopoletin, pyrogallol, and dihydroferulic acid, and 16 bound polyphenols, especially p-coumaric acid, feruloyl hexoside, and caffeic acid. A significant correlation was observed between the generation and degradation of polyphenols, and specific bound polyphenols peaked during the 24-48 h fermentation. Furthermore, reduced surface roughness and galacturonic acid content in wolfberry residue, along with increased pectinase activity, suggested substantial pectin degradation in the cell wall, which may be associated with the release of polyphenols, due to pectin serving as carriers for bound polyphenols. The fermentation also increased polyphenol oxidase and peroxidase activity, contributing to polyphenol breakdown. These findings provide insights for improving wolfberry juice production.

Influence of supplementation with iron and probiotic bacteria Lactobacillus plantarum and Lactobacillus curvatus on selected parameters of inflammatory state in rats on a high-fat iron-deficient diet

BACKGROUND

A high-fat (HF) diet, diet iron deficiency and iron supplementation may affect inflammatory parameters. Probiotics influence both iron metabolism and inflammation. We compared the inflammatory state in rats on a HF iron-deficient diet receiving oral iron, Lactobacillus plantarum and Lactobacillus curvatus in different combinations.

METHODS

This was a two-stage experiment. In groups C (n = 8) and HF (n = 8), rats ate a control or HF diet, respectively, for 16 weeks. In the group HFDEF (n = 48), rats ate a HF iron-deficient diet for 8 weeks (first stage) and were subsequently divided into 6 groups (n = 8 each) receiving the following for a further 8 weeks (second stage): HFDEF - a HF iron-deficient diet; HFDEFFe - a HF iron-deficient diet with iron; HFDEFLp and HFDEFLc - a HF iron-deficient diet with L. plantarum or L. curvatus, respectively; and HFDEFFeLp and HFDEFFeLc - a HF iron-deficient diet with iron and L. plantarum or L. curvatus, respectively. Body composition analysis and blood sampling was performed. Markers of iron status and levels of total antioxidant status (TAS), C-reactive protein (CRP), tumour necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were measured in the blood.

RESULTS

TAS was higher in the HFDEF group (756.57 ± 489.53 ng mL-1) versus the HFDEFLc group (187.04 ± 47.84 ng mL-1; P = 0.022). No more differences were found between groups, or in TAS, CRP, TNF-α and IL-6 concentrations. Also, no differences were found between groups for alanine and aspartate aminotransferases, glucose, total cholesterol, low- and high-density lipoproteins and triglycerides. TAS level was positively correlated with ferritin concentration, IL-6 with TAS and TNF-α with hepcidin level.

CONCLUSIONS

Supplementation with L. plantarum, L. curvatus and iron in combinations exerts no influence on inflammatory status, lipid profile, hepatic function and serum fasting glucose in rats on a HF iron-deficient diet. © 2024 Society of Chemical Industry.

Modulation of chronic obstructive pulmonary disease progression by antioxidant metabolites from Pediococcus pentosaceus: enhancing gut probiotics abundance and the tryptophan-melatonin pathway

Chronic obstructive pulmonary disease (COPD), a condition primarily linked to oxidative stress, poses significant health burdens worldwide. Recent evidence has shed light on the association between the dysbiosis of gut microbiota and COPD, and their metabolites have emerged as potential modulators of disease progression through the intricate gut-lung axis. Here, we demonstrate the efficacy of oral administration of the probiotic Pediococcus pentosaceus SMM914 (SMM914) in delaying the progression of COPD by attenuating pulmonary oxidative stress. Specially, SMM914 induces a notable shift in the gut microbiota toward a community structure characterized by an augmented abundance of probiotics producing short-chain fatty acids and antioxidant metabolisms. Concurrently, SMM914 synthesizes L-tryptophanamide, 5-hydroxy-L-tryptophan, and 3-sulfino-L-alanine, thereby enhancing the tryptophan-melatonin pathway and elevating 6-hydroxymelatonin and hypotaurine in the lung environment. This modulation amplifies the secretion of endogenous anti-inflammatory factors, diminishes macrophage polarization toward the M1 phenotype, and ultimately mitigates the oxidative stress in mice with COPD. The demonstrated efficacy of the probiotic intervention, specifically with SMM914, not only highlights the modulation of intestine microbiota but also emphasizes the consequential impact on the intricate interplay between the gastrointestinal system and respiratory health.

A novel pathway of levodopa metabolism by commensal Bifidobacteria

The gold-standard treatment for Parkinson's disease is levodopa (L-DOPA), which is taken orally and absorbed intestinally. L-DOPA must reach the brain intact to exert its clinical effect; peripheral metabolism by host and microbial enzymes is a clinical management issue. The gut microbiota is altered in PD, with one consistent and unexplained observation being an increase in Bifidobacterium abundance among patients. Recently, certain Bifidobacterium species were shown to have the ability to metabolize L-tyrosine, an L-DOPA structural analog. Using both clinical cohort data and in vitro experimentation, we investigated the potential for commensal Bifidobacteria to metabolize this drug. In PD patients, Bifidobacterium abundance was positively correlated with L-DOPA dose and negatively with serum tyrosine concentration. In vitro experiments revealed that certain species, including B. bifidum, B. breve, and B. longum, were able to metabolize this drug via deamination followed by reduction to the compound 3,4-dihydroxyphenyl lactic acid (DHPLA) using existing tyrosine-metabolising genes. DHPLA appears to be a waste product generated during regeneration of NAD +. This metabolism occurs at low levels in rich medium, but is significantly upregulated in nutrient-limited minimal medium. Discovery of this novel metabolism of L-DOPA to DHPLA by a common commensal may help inform medication management in PD.

The Effect of Indole-3-Lactic Acid from Lactiplantibacillus plantarum ZJ316 on Human Intestinal Microbiota In Vitro

Microbiota-derived tryptophan metabolites are essential signals for maintaining gut homeostasis, yet the potential contribution to modulating gut microbiota has been rarely investigated. In this study, Lactiplantibacillus plantarum ZJ316 (CCTCC No. M 208077) with a high production (43.14 μg/mL) of indole-3-lactic acid (ILA) was screened. ILA with 99.00% purity was prepared by macroporous resin, Sephadex G–25 and reversed-phase high-performance liquid chromatography. Purified ILA can effectively inhibit foodborne pathogens such as Salmonella spp., Staphylococcus spp., Escherichia coli and Listeria monocytogenes. In an in vitro model of the human gut microbiota, a medium-dose ILA (172 mg/L) intervention increased the average relative abundance of phyla Firmicutes and Bacteroidota by 9.27% and 15.38%, respectively, while Proteobacteria decreased by 14.36% after 24 h fermentation. At the genus level, the relative abundance of Bifidobacterium and Faecalibacterium significantly increased to 5.36 ± 2.31% and 2.19 ± 0.77% (p < 0.01), respectively. Escherichia and Phascolarctobacterium decreased to 16.41 ± 4.81% (p < 0.05) and 2.84 ± 1.02% (p < 0.05), respectively. Intestinal short-chain fatty acids, especially butyric acid, were significantly increased (2.98 ± 0.72 µmol/mL, p < 0.05) and positively correlated with Oscillospira and Collinsella. Overall, ILA has the potential to regulate the gut microbiota, and an in-depth understanding of the relationship between tryptophan metabolites and gut microbiota is needed in the future.

Torquetenovirus in pregnancy: Correlation with vaginal microbiome, metabolome and pro-inflammatory cytokines

Torquetenovirus (TTV) is a negative sense, single-stranded DNA virus present in many body fluids of apparently healthy individuals. At present, it is considered a non-pathogenic endogenous virus. TTV can be detected in the vagina of pregnant women, its abundance being modulated with the extent of immune system activation. Until now, there is only scarce information regarding the association between TTV and the composition of the vaginal environment. Therefore, this study aimed to assess the presence of TTV in the vaginal ecosystem of a cohort of white women with a normal pregnancy (n = 60) at different gestational stages (first, second and third trimester) and in 9 subjects suffering a first trimester miscarriage. For each woman, we determined (i) the presence and titer of TTV, (ii) the vaginal bacterial composition by means of Nugent score and 16S rRNA gene sequencing, (iii) the vaginal metabolic profiles through ¹H-NMR spectroscopy, and (iv) the vaginal concentration of two pro-inflammatory cytokines (IL-6 and IL-8). More than one third of women were found negative for TTV at all gestational stages. Although not statistically significant, the positivity for TTV dropped from 53.3% in the first to 36.6% in the third trimester. TTV loads varied greatly among vaginal samples, ranging between 2 × 10¹ and 2 × 10⁵ copies/reaction. No difference in TTV prevalence and loads was observed between women with normal pregnancies and miscarriages. The presence of TTV was more common in women with a higher vaginal leucocyte count (p = 0.02). The levels of IL-6 (p = 0.02), IL-8 (p = 0.03), propionate (p = 0.001) and cadaverine (p = 0.006) were significantly higher in TTV-positive samples. TTV titer was positively correlated with the concentrations of 4-hydroxyphenyllactate (p < 0.0001), isoleucine (p = 0.01) and phenylalanine (p = 0.04). TTV-positive samples were characterized by a higher relative abundance of Sneathia (p = 0.04) and Shuttleworthia (p = 0.0009). In addition, a trend toward a decrease of Lactobacillus crispatus and Lactobacillus jensenii, and an increase of Lactobacillus iners was observed for TTV-positive samples. In conclusion, we found that TTV is quite common in women with normal pregnancy outcomes, representing a possible predictor of local immune status.

Tryptophan regulates bile and nitrogen metabolism in two pig gut lactobacilli species in vitro based on metabolomics study

Research has demonstrated that tryptophan (Trp) regulated the composition and metabolism of the gut microbiota. However, the detailed mode of action of Trp on the metabolism of intestinal commensal lactobacilli has not been well characterized. This study aimed to compare the effects of Trp concentration (0.2, 0.4, 0.6 mmol/L) in the media on the metabolism of Lactobacillus amylovorus and Limosilactobacillus mucosae isolated from the small intestine of piglets in vitro by high-performance liquid chromatography and metabolomics study. Results showed that increased Trp concentration increased (P < 0.05) net utilization of lysine, methionine, tryptophan, asparagine/aspartate, glutamine/glutamate, however, increased net production of glycine and taurine in Lac. amylovorus. In contrast, increased Trp concentration decreased (P < 0.05) net utilization of leucine, phenylalanine, and serine and increased (P < 0.05) net utilization of arginine and net production of ornithine and glycine in Lim. mucosae. Targeted metabolomics analysis showed that increased Trp concentration promoted (P < 0.05) the production of indole-3-lactic acid and 3-indoleacetic acid in the two lactobacilli strains. Increased concentration of Trp increased (P < 0.01) glycochenodeoxycholic acid metabolism in Lim. mucosae and glycocholic acid and taurocholic acid metabolism in Lac. amylovorus. Untargeted metabolomics analysis showed that metabolic pathways related to phenylalanine and tryptophan metabolism, and nicotinate and nicotinamide metabolism were regulated by Trp in Lim. mucosae. These findings will help develop new biomarkers and dietary strategies to maintain the functionality of the gut microbiota aiming at improving the nutrition and health of both humans and animals.

Antioxidant Activity, Microbiological Quality, and Acceptability of Spontaneously Fermented Shrimp Sausage (Litopenaeus vannamei)

Fermented shrimp sausages are prepared spontaneously with Litopenaeus vannamei as raw material. Shrimp is one of the marine sources with rich chitosan as bioactive compounds, antioxidants, vitamin E, and probiotic lactic acid bacteria (LAB) produced by fermentation processes. This study aimed to analyze the variations in antioxidant activity, vitamin E content, total LAB, total pathogenic bacteria, pH, and acceptability of shrimp sausage produced at different fermentation times. A completely randomized experimental design study was performed using four levels of exposure time, including control (0 days), 1, 2, and 3 days. The treatment was conducted spontaneously with 1.2% salt concentration, a drying temperature of 50°C for 3 h, and fermentation at 35°C. The evaluated parameters included the antioxidant activity measured with the radical 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) method, vitamin E levels by high-performance liquid chromatography, total LAB with total plate count, and Escherichia coli bacteria by the most probable number method. Salmonella sp. and Staphylococcus aureus were estimated by the identification method. A pH meter was used to assess acidity, and hedonic organoleptic testing was performed for taste, aroma, color, and texture. The results show significant differences in antioxidant activity, vitamin E, and shrimp sausage acceptability at varied fermentation times $\left(p\le 0.05\right)$ . However, the best formulation was obtained with the first-day fermented shrimp sausage, as shown by its bioactive content and the level of acceptability.

Influence of multistrain probiotic and iron supplementation on iron status in rats

OBJECTIVE

The impact of multistrain probiotics on iron (Fe) metabolism under Fe-deficient diet conditions remains unknown. The study aimed to compare the effect of 6 weeks simultaneous and exclusive oral multistrain probiotic and iron supplementation on selected parameters of Fe metabolism in rats on an Fe-deficient diet.

METHODS

Forty rats were assigned to five groups, with eight animals in each, and for 6 weeks received: the CC group- a standard diet, the DD group- an Fe-deficient diet, the DPB group- an Fe-deficient with a multispecies probiotic, the DFE group- an Fe-deficient diet supplemented with iron, the DPBFE group- an Fe-deficient diet with iron and a multispecies probiotic. The Fe content in blood and tissues; serum concentration of erythroferrone, ferritin (Ft), homocysteine, hepcidin (HEPC) and lactoferrin; liver content of divalent metal transporter 1 (DMT1), transferrin receptor protein 1 (TfR1) and 2 (TfR2) and ZRT/IRT-like protein 14 (ZIP14) and faecal microbiota were assessed.

RESULTS

In DPBFE group, unlike in DPB and DFE groups, duodenal Fe content was higher compared to DD group. Similarly, serum Ft level was higher in DPBFE group, but not in DPB and DFE groups, compared to DD group.

CONCLUSIONS

Six weeks simultaneous oral multistrain probiotic and Fe supplementation, but not exclusive probiotic or Fe intake, increases duodenal Fe absorption in rats and presents higher effectiveness in increasing tissue Fe stores.

UPLC-QTOF-MS/MS and GC-MS Characterization of Phytochemicals in Vegetable Juice Fermented Using Lactic Acid Bacteria from Kimchi and Their Antioxidant Potential

This study aims to investigate fermentative metabolites in probiotic vegetable juice from four crop varieties (Brassica oleracea var. capitata, B. oleracea var. italica, Daucus carota L., and Beta vulgaris) and their antioxidant properties. Vegetable juice was inoculated with two lactic acid bacteria (LAB) (Companilactobacillus allii WiKim39 and Lactococcus lactis WiKim0124) isolated from kimchi and their properties were evaluated using untargeted UPLC-QTOF-MS/MS and GC-MS. The samples were also evaluated for radical (DPPH^• and OH^•) scavenging activities, lipid peroxidation, and ferric-reducing antioxidant power. The fermented vegetable juices exhibited high antioxidant activities and increased amounts of total phenolic compounds. Fifteen compounds and thirty-two volatiles were identified using UPLC-QTOF-MS/MS and GC-MS, respectively. LAB fermentation significantly increased the contents of d-leucic acid, indole-3-lactic acid, 3-phenyllactic acid, pyroglutamic acid, γ-aminobutyric acid, and gluconic acid. These six metabolites showed a positive correlation with antioxidant properties. Thus, vegetable juices fermented with WiKim39 and WiKim0124 can be considered as novel bioactive health-promoting sources.

Differential Distribution of Tryptophan-Metabolites in Fetal and Maternal Circulations During Normotensive and Preeclamptic Pregnancies

Preeclampsia (PE) is a hypertensive pregnancy, which is a leading cause of maternal and fetal morbidity and mortality during pregnancy. L-Tryptophan (Trp) is an essential amino acid, which can be metabolized into various biologically active metabolites. However, the levels of many circulating Trp-metabolites in human normotensive pregnancies (NT) and PE are undetermined. This study quantified the levels of Trp-metabolites in maternal and umbilical vein sera from women with NT and PE. Paired maternal and umbilical blood samples were collected from singleton pregnant patients. Twenty-five Trp-metabolites were measured in serum samples using liquid chromatography with tandem mass spectrometry. The effects of L-kynurenine (Kyn) and indole-3-lactic acid (ILA), on function of human umbilical vein endothelial cells (HUVECs), were also determined. Twenty Trp-metabolites were detected. The levels of 9 Trp-metabolites including Kyn and ILA were higher (P < 0.05) in umbilical vein than maternal serum, whereas 2 (5-hydroxy-L-tryptophan and serotonin) were lower (P < 0.05) in umbilical vein compared to maternal serum. PE significantly (P < 0.05) elevated ILA levels in maternal and umbilical vein sera. Kyn dose-dependently decreased (P < 0.05) cell viability. Kyn and ILA dose- and time-dependently (P < 0.05) increased monolayer integrity in HUVECs. These data suggest that these Trp-metabolites are important in regulating endothelial function during pregnancy, and the elevated ILA in PE may antagonize increased endothelial permeability occurring in PE.

Lactobacillus rhamnosus GG modifies the metabolome of pathobionts in gnotobiotic mice

Background

Lactobacillus rhamnosus GG (LGG) is the most widely used probiotic, but the mechanisms underlying its beneficial effects remain unresolved. Previous studies typically inoculated LGG in hosts with established gut microbiota, limiting the understanding of specific impacts of LGG on host due to numerous interactions among LGG, commensal microbes, and the host. There has been a scarcity of studies that used gnotobiotic animals to elucidate LGG-host interaction, in particular for gaining specific insights about how it modifies the metabolome. To evaluate whether LGG affects the metabolite output of pathobionts, we inoculated with LGG gnotobiotic mice containing Propionibacterium acnes, Turicibacter sanguinis, and Staphylococcus aureus (PTS).

Results

16S rRNA sequencing of fecal samples by Ion Torrent and MinION platforms showed colonization of germ-free mice by PTS or by PTS plus LGG (LTS). Although the body weights and feeding rates of mice remained similar between PTS and LTS groups, co-associating LGG with PTS led to a pronounced reduction in abundance of P. acnes in the gut. Addition of LGG or its secretome inhibited P. acnes growth in culture. After optimizing procedures for fecal metabolite extraction and metabolomic liquid chromatography-mass spectrometry analysis, unsupervised and supervised multivariate analyses revealed a distinct separation among fecal metabolites of PTS, LTS, and germ-free groups. Variables-important-in-projection scores showed that LGG colonization robustly diminished guanine, ornitihine, and sorbitol while significantly elevating acetylated amino acids, ribitol, indolelactic acid, and histamine. In addition, carnitine, betaine, and glutamate increased while thymidine, quinic acid and biotin were reduced in both PTS and LTS groups. Furthermore, LGG association reduced intestinal mucosal expression levels of inflammatory cytokines, such as IL-1α, IL-1β and TNF-α.

Conclusions

LGG co-association had a negative impact on colonization of P. acnes, and markedly altered the metabolic output and inflammatory response elicited by pathobionts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02178-2.

Metabolome and Microbiota Analysis Reveals the Conducive Effect of Pediococcus acidilactici BCC-1 and Xylan Oligosaccharides on Broiler Chickens

Xylan oligosaccharides (XOS) can promote proliferation of Pediococcus acidilactic BCC-1, which benefits gut health and growth performance of broilers. The study aimed to investigate the effect of Pediococcus acidilactic BCC-1 (referred to BBC) and XOS on the gut metabolome and microbiota of broilers. The feed conversion ratio of BBC group, XOS group and combined XOS and BBC groups was lower than the control group (P < 0.05). Combined XOS and BBC supplementation (MIX group) elevated butyrate content of the cecum (P < 0.05) and improved ileum morphology by enhancing the ratio of the villus to crypt depth (P < 0.05). The 16S rDNA results indicated that both XOS and BBC induced high abundance of butyric acid bacteria. XOS treatment elevated Clostridium XIVa and the BBC group enriched Anaerotruncus and Faecalibacterium. In contrast, MIX group induced higher relative abundance of Clostridiaceae XIVa, Clostridiaceae XIVb and Lachnospiraceae. Besides, MIX group showed lower abundance of pathogenic bacteria such as Campylobacter. Metabolome analysis showed that all the 3 treatment groups (XOS, BBC and MIX) showed lower concentrations of sorbitol and both XOS and BBC group had higher concentrations of pyridoxine levels than CT group. Besides, XOS and BBC groups enhanced the content of hydroxyphenyl derivatives 4-hydroxyphenylpyruvate 1 and 3-(3-hydroxyphenyl) propionic acid, respectively (P < 0.05). Notably, MIX group enhanced both 4-hydroxyphenylpyruvate 1 and 3-(3-hydroxyphenyl) propionic acid (P < 0.05). Thus, XOS and BBC may have a synergistic role to improve the performance of broilers by modulating gut microbiota and metabolome.

The impact of indole-3-lactic acid on immature intestinal innate immunity and development: a transcriptomic analysis

An excessive intestinal inflammatory response may have a role in the pathogenesis of necrotizing enterocolitis (NEC) in very preterm infants. Indole-3-lactic acid (ILA) of breastmilk tryptophan was identified as the anti-inflammatory metabolite involved in probiotic conditioned media from Bifidobacteria longum subsp infantis. This study aimed to explore the molecular endocytic pathways involved in the protective ILA effect against inflammation. H4 cells, Caco-2 cells, C57BL/6 pup and adult mice were used to compare the anti-inflammatory mechanisms between immature and mature enterocytes in vitro and in vivo. The results show that ILA has pleiotropic protective effects on immature enterocytes including anti-inflammatory, anti-viral, and developmental regulatory potentials in a region-dependent and an age-dependent manner. Quantitative transcriptomic analysis revealed a new mechanistic model in which STAT1 pathways play an important role in IL-1β-induced inflammation and ILA has a regulatory effect on STAT1 pathways. These studies were validated by real-time RT-qPCR and STAT1 inhibitor experiments. Different protective reactions of ILA between immature and mature enterocytes indicated that ILA's effects are developmentally regulated. These findings may be helpful in preventing NEC for premature infants.

Lactic Acid Fermentation of Arthrospira platensis (Spirulina) in a Vegetal Soybean Drink for Developing New Functional Lactose-Free Beverages

The main objective of this study was to evaluate the suitability of Arthrospira platensis F&M-C256 (spirulina) biomass in a vegetal soybean drink or in water, as substrate for lactic acid fermentation by the probiotic bacterium Lactiplantibacillus plantarum ATCC 8014 (LAB8014) and to evaluate the fermented products in terms of bacteria content and organic acids content, biochemical composition, total phenolics, and phycocyanin content, in vitro digestibility, in vitro and in vivo antioxidant activity. After 72 h of fermentation, a bacterial concentration of about 10.5 log CFU mL^–1 in the broths containing the soybean drink + spirulina + LAB8014 (SD + S + LAB8014) or water + spirulina + LAB8014 (W + S + LAB8014) was found. Lactic acid concentration reached similar values (about 1.7 g L^–1) in the two broths, while a different acetic acid concentration between SD + S + LAB8014 and W + S + LAB8014 broths was observed (7.7 and 4.1 g L^–1, respectively). A. platensis biomass was shown to be a suitable substrate for LAB8014 growth. After fermentation, both broths contained a high protein content (>50%). In both broths, total phenolics, in vitro and in vivo antioxidant activity increased after fermentation (+35, +20, and +93% on average, respectively), while phycocyanin content decreased (−40% on average). Digestibility of W + S + LAB8014 broth statistically improved after fermentation. This study highlights the potential of A. platensis F&M-C256 biomass as a substrate for the production of new functional lactose-free beverages.

Insights into the reason of Human-Residential Bifidobacteria (HRB) being the natural inhabitants of the human gut and their potential health-promoting benefits

Members of Bifidobacterium are among the first microbes to colonise the human gut, and certain species are recognised as the natural resident of human gut microbiota. Their presence in the human gut has been associated with health-promoting benefits and reduced abundance of this genus is linked with several diseases. Bifidobacterial species are assumed to have coevolved with their hosts and include members that are naturally present in the human gut, thus recognised as Human-Residential Bifidobacteria (HRB). The physiological functions of these bacteria and the reasons why they occur in and how they adapt to the human gut are of immense significance. In this review, we provide an overview of the biology of bifidobacteria as members of the human gut microbiota and address factors that contribute to the preponderance of HRB in the human gut. We highlight some of the important genetic attributes and core physiological traits of these bacteria that may explain their adaptive advantages, ecological fitness, and competitiveness in the human gut. This review will help to widen our understanding of one of the most important human commensal bacteria and shed light on the practical consideration for selecting bifidobacterial strains as human probiotics.

Hepcidin and Erythroferrone Correlate with Hepatic Iron Transporters in Rats Supplemented with Multispecies Probiotics

The influence of probiotic supplementation on iron metabolism remains poorly investigated. However, a range of studies, especially on Lactobacillus plantarum 299v (Lp229v), have indicated a possible positive impact of probiotics on iron absorption. The aim of the study was to determine the effect of multistrain probiotic supply on iron balance. Thirty Wistar rats were randomized into three groups: placebo (KK group), and multistrain probiotic per os in a daily dose of 2.5 × 10⁹ colony forming units (CFU) (PA group) or 1 × 10¹⁰ CFU (PB group). Multistrain probiotic consisted of nine bacterial strains: Bifidobacterium bifidum W23, B. lactis W51, B. lactis W52, Lactobacillus acidophilus W37, L. brevis W63, L. casei W56, L. salivarius W24, Lactococcus lactis W19, and Lc. lactis W58, in equal proportions. After six weeks, blood and organ samples were collected. No differences were found between the three groups in terms of serum concentrations of hepcidin (HEPC), lactoferrin (LTF), homocysteine (HCY), ferritin (Ft), or erythroferrone (ErFe), or in liver content of divalent metal transporter 1 (DMT1), transferrin receptors 1 and 2 (TfR), or ZRT/IRT-like protein 14 (ZIP14) proteins. In the overall sample, positive correlations were noted between the serum concentrations of hepcidin and lactoferrin, and hepcidin and ferritin; serum concentration of hepcidin and DMT1 and TfR1 in the liver; and serum concentration of erythroferrone and TfR2 in the liver. The correlations of serum hepcidin and erythroferrone with liver DMT1 and TfR represent significant mechanisms of Fe homeostasis. Our study has shown that multistrain probiotic supplementation used in the experiment did not disrupt the biochemical and hepatic regulatory processes of Fe balance and did not demonstrate significant influence on selected parameters of Fe metabolism.

Potential Effects of Indole-3-Lactic Acid, a Metabolite of Human Bifidobacteria, on NGF-induced Neurite Outgrowth in PC12 Cells

Gut microbiota-derived tryptophan metabolites such as indole derivatives are an integral part of host metabolome that could mediate gut-brain communication and contribute to host homeostasis. We previously reported that infant-type Human-Residential Bifidobacteria (HRB) produced higher levels of indole-3-lactic acid (ILA), suggesting the former might play a specific role in microbiota-host crosstalk by producing ILA in human infants. Nonetheless, the biological meaning of bifidobacteria-derived ILA in infant health development remains obscure. Here, we sought to explore the potential role of ILA in neuronal differentiation. We examined the neurite outgrowth and acetylcholinesterase (AchE) activity of PC12 cells following exposure to ILA and NGF induction. We found that ILA substantially enhanced NGF-induced neurite outgrowth of PC12 cells in a dose-dependent manner, and had the most prominent effect at 100 nM. Significant increases in the expression of TrkA receptor, ERK1/2 and CREB were observed in ILA-treated PC12 cells, suggesting ILA potentiated NGF-induced neurite outgrowth through the Ras/ERK pathway. Additionally, ILA was found to act as the aryl hydrocarbon receptor (AhR) agonist and evoked NGF-induced neurite outgrowth in an AhR-mediated manner. These new findings provide clues into the potential involvement of ILA as the mediator in bifidobacterial host-microbiota crosstalk and neuronal developmental processes.

The Facilitating Effect of Tartary Buckwheat Flavonoids and Lactobacillus plantarum on the Growth Performance, Nutrient Digestibility, Antioxidant Capacity, and Fecal Microbiota of Weaned Piglets

Simple Summary

There has been a growing interest in the use of flavonoids and probiotics as alternatives of antibiotics in livestock production and as natural products for human health benefit. The effect of tartary buckwheat flavonoid supplementation in the diet has not been clearly investigated. The supplementation of tartary buckwheat flavonoids or Lactobacillus plantarum improved the growth performance, nutrient digestibility, and antioxidant capacity of weaned piglets. In combination, they exhibited a synergistic effect on nutrient digestibility.

Abstract

Natural plant extracts and probiotics has been proved as the most preferred and effective alternatives for antibiotics in animal feeding. The current study aimed to investigate the facilitating effect of tartary buckwheat flavonoids and Lactobacillus plantarum on the growth performance, nutrient digestibility, antioxidant capacity, and microbiota of weaned piglets. Fifty 35-day-old weaned piglets (7.85 ± 0.67 kg) were randomly divided into five treatments with 10 piglets per treatment. Piglets in the negative control (NC) group were fed a basal diet, and others were fed basal diets supplemented with 40 mg/kg of colistin sulfate (positive control, PC), 10⁹ CFU/kg Lactobacillus plantarum (LP), 40 mg/kg of tartary buckwheat flavonoids (BF), and a combination of 10⁹ CFU/kg Lactobacillus plantarum and 40 mg/kg of tartary buckwheat flavonoids (LB). Supplementation of BF increased the average daily gain of piglets in the BF group (p < 0.05). The nutrient digestibility of piglets in the NC group was lower than that in other groups, while the digestibility of gross energy, dry matter, organic matter, and phosphorus of piglets in the LB group was higher than the other four groups (p < 0.05). Compared with the NC and pC group, supplementation of Lp increased the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-px), and catalase (CAT), while the BF increased the content of IgA and IgM (p < 0.05). Supplementation of colistin sulfate decreased the alpha diversity index, including chao and observed species, while the addition of Lp or combination of Lp and BF increased the abundance of Selenomonas or Mitsuokella in fecal samples, respectively. The results indicated that supplementation of Lactobacillus plantarum can improve the antioxidant capacity, while tartary buckwheat flavones can increase the growth performance and immune ability of weaned piglets. Moreover, in combination, they promote nutrient digestibility.

Production of Indole-3-Lactic Acid by Bifidobacterium Strains Isolated fromHuman Infants

Recent studies have shown that metabolites produced by microbes can be considered as mediators of host-microbial interactions. In this study, we examined the production of tryptophan metabolites by Bifidobacterium strains found in the gastrointestinal tracts of humans and other animals. Indole-3-lactic acid (ILA) was the only tryptophan metabolite produced in bifidobacteria culture supernatants. No others, including indole-3-propionic acid, indole-3-acetic acid, and indole-3-aldehyde, were produced. Strains of bifidobacterial species commonly isolated from the intestines of human infants, such as Bifidobacterium longum subsp. longum, Bifidobacterium longum subsp. infantis, Bifidobacterium breve, and Bifidobacterium bifidum, produced higher levels of ILA than did strains of other species. These results imply that infant-type bifidobacteria might play a specific role in host-microbial cross-talk by producing ILA in human infants.

The effect of multistrain probiotic supplementation in two doses on iron metabolism in obese postmenopausal women: a randomized trial

Obesity leads to detrimental abnormalities of iron (Fe) metabolism. So far, studies have shown that single-strain probiotic supplementation ameliorates the gut microbiota quality disrupted in the obese and improves Fe homeostasis. The effect of multistrain probiotic supplementation and its dose-dependence in obese postmenopausal women remain unknown. The study aimed to investigate the effect of multistrain probiotic supplementation in two doses on selected parameters of Fe metabolism in obese postmenopausal female patients. Three groups of obese postmenopausal women, 30 subjects each, received nine-strain oral probiotic supplement at a daily dose of 2.5 × 10⁹ CFU (LD group), 1 × 10¹⁰ CFU (HD group), or placebo for 12 weeks (ClinicalTrails.gov no: NCT03100162). After the intervention, the hair Fe content was lower in both supplemented groups compared to the baseline, the serum zinc (Zn) concentration was higher in the LD group and lower in the HD group vs. the baseline, and the serum erythroferrone (FAM) concentration was lower in the HD group and serum ferritin (FE) concentration was higher in the LD group vs. the baseline. In the whole study population after the completion of the intervention hair Zn correlated positively with serum HEPC and FAM and negatively with serum FE. Hair Fe correlated negatively with serum FE. It is concluded that multistrain probiotic supplementation may influence iron metabolism in obese postmenopausal female patients.

Antioxidant capacity of soymilk yogurt and exopolysaccharides produced by lactic acid bacteria

Reactive oxygen species (ROS), such as hydroxyl and superoxide anion radicals, are highly reactive molecules derived from the metabolism of oxygen. ROS play positive roles in cell physiology, but they may also damage cell membranes and DNA, inducing oxidation that causes membrane lipid peroxidation and decreases membrane fluidity. Soymilk yogurt, which is soymilk fermented using lactic acid bacteria (LAB), is an excellent food item with numerous functional substances with antioxidant effects. In this study, the antioxidative activities of soymilk yogurt were investigated. Sixteen of the 26 tested LAB strains solidified soymilk. In antioxidant capacity tests for bacterial cells, Leuconostoc mesenteroides MYU 60 and Pediococcus pentosaceus MYU 759 showed the highest values in the oxygen radical antioxidant capacity (ORAC) and hydroxyl radical antioxidant capacity (HORAC) tests, respectively. The supernatant of soymilk yogurt made with Lactobacillus gasseri MYU 1 showed the highest ORAC and HORAC values. L. mesenteroides MYU 60, Lactobacillus plantarum MYU 74, Lactobacillus reuteri MYU 220, and P. pentosaceus MYU 759 showed significantly high N-acetylcysteine equivalent values compared with the control in a total ROS reducing assay (p<0.05). These strains were selected, and a comet assay was performed, which exhibited decreased values in all selected strains compared with the control, indicating DNA protection. An acidic exopolysaccharide produced by P. pentosaceus MYU 759 showed high antioxidant capacity. The antioxidant substances produced by LAB fermentation may be exopolysaccharides, antioxidant peptides, and isoflavone aglycones. Soymilk yogurt can be used as a functional food useful for various diseases related to oxidation.

New lactic acid bacteria for skin health via oral intake of heat-killed or live cells

Lactic acid bacteria play an essential role in the food industry in the manufacture of many fermented products (cheese, yogurt, fermented vegetables, etc.). Application of these organisms is now being extended to the area of health improvement, as their probiotic activities become known. Probiotics are defined as viable microorganisms that exert a beneficial effect on the health of the host when they are ingested in sufficient quantity. Lactic acid bacteria and bifidobacteria isolated from the human intestine are the most common probiotics used for human consumption. The development of new probiotics with new beneficial effects is eagerly awaited in the food industry. This review introduces Lactococcus, which are one of the genera of lactic acid bacteria and are mainly isolated from dairy products and fermented vegetables, as new probiotics, focusing especially on Lactococcus lactis H61, which improves skin status in Japanese women with oral intake of heat‐killed or live cells. The deduced mechanisms associated with the beneficial effects of strain H61 are also discussed.

Study on the chemical and microbial composition and probiotic characteristics of dominant lactic acid bacteria in fermented poultry slaughterhouse waste

This study aimed to evaluate the quality of fermented poultry slaughterhouse waste and isolate and identify the probiotic bacteria present in it. Poultry slaughterhouse waste samples supplemented with 5% starter culture and 0.2% propionic acid received one of four experimental treatments, which consisted of further supplementation with: (1) 10% molasses (M10); (2) 15% molasses (M15); (3) 10% molasses with 200ppm butylated hydroxytoluene (MB10); and (4) 15% molasses with 200ppm butylated hydroxytoluene (MB15). All experimental treatments (silages) were fermented for 6days with sampling before fermentation (day 1) and at the end of days 3 and 6. The pH of the silages decreased during the fermentation as it was lower on days 3 and 6 than day 1 (P<0.05). On day 6 of the experiment, the number of lactic acid bacteria in MB15 was significantly (P<0.05) higher than in MB10. The percentage of non-protein nitrogen increased (P<0.05) on days 3 and 6 of fermentation. The amount of malondialdehyde indicated that the peroxidation ratio decreased (P<0.05) with increasing the fermentation time. Among the 23 lactic acid bacteria detected in MB15, nine isolates (39.1%) belonged to the species Lactobacillus plantarum, ten (43.5%) belonged to the species Lactobacillus rhamnosus, and four (43.5%) belonged to the species Lactobacillus fermentum. The isolates LPL9, LRH25, and LFE26 were identified as the strain of L. plantarum, L. ramnosus, and L. fermentum, respectively, that demonstrated the best characteristics for use as a probiotic. The results of this experiment indicated that the fermentation is an advisable method for reusing the nutrients of poultry slaughterhouse waste and producing a probiotic supplement.

Identification of the key excreted molecule by Lactobacillus fermentum related to host iron absorption

We have taken a vital step towards understanding why probiotic bacteria increase iron absorption in the gastrointestinal tract. We show here that Lactobacillus fermentum, one of the main probiotics of the microbiota, exhibits an extraordinary ferric-reducing activity. This activity is predominantly due to an excreted molecule: p-hydroxyphenyllactic acid (HPLA). Reduction of Fe(III) to Fe(II) is essential for iron absorption in the gastrointestinal tract. By reducing Fe(III), HPLA boosts Fe(II) absorption through the DMT1 channels of enterocytes. An in vitro experiment tested and confirmed this hypothesis. This discovery opens new avenues for the treatment of iron deficiency in humans, one of the most common and widespread nutritional disorders in the world.

Isolation and antioxidative activity of amino acid derivatives produced by Leuconostoc mesenteroides

One new phenyl lactic acid derivative, N-(5-amino-2-hydroxy-1-oxopentyl)-tyrosine (2), and three known metabolites [(S)-8-hydroxy-4-hydroxy-phenylpropanoic acid (1), (S)-8-hydroxy-phenylpropanoic acid (3), and indole-(S)-3-lactic acid (4)] were isolated from the culture medium of Leuconostoc mesenteroides guided with DPPH radical-scavenging assay. The chemical structures of the isolated compounds were determined by NMR and electrospray ionization mass spectroscopy. The isolated four compounds were assumed to be metabolites formed by the transformation of amino acids. The DPPH radical-scavenging activities of 1 and 2 were significantly higher than those of 3 and 4. This result may provide meaningful information of antioxidative metabolites from lactic acid bacteria.

Latifolicinin A from a Fermented Soymilk Product and the Structure-Activity Relationship of Synthetic Analogues as Inhibitors of Breast Cancer Cell Growth

The functional components in soymilk may vary depending upon the fermentation process. A fermented soymilk product (FSP) obtained by incubation with the microorganisms of intestinal microflora was found to reduce the risk of breast cancer. Guided by the inhibitory activities against breast cancer cells, two cytotoxic compounds, daidzein and (S)-latifolicinin A, were isolated from the FSP by repetitive extraction and chromatography. Latifolicinin A is the n-butyl ester of β-(4-hydroxyphenyl)lactic acid (HPLA). A series of the ester and amide derivatives of (S)-HPLA and L-tyrosine were synthesized for evaluation of their cytotoxic activities. In comparison, (S)-HPLA derivatives exhibited equal or superior inhibitory activities to their L-tyrosine counterparts, and (S)-HPLA amides showed better cytotoxic activities than their corresponding esters. In particular, (S)-HPLA farnesyl amide was active to triple-negative MDA-MB-231 breast cancer cells (IC50 = 27 μM) and 10-fold less toxic to Detroit-551 normal cells.