Antioxidant status and gut microbiota change in an aging mouse model as influenced by exopolysaccharide produced by Lactobacillus plantarum YW11 isolated from Tibetan kefir

Improving the Antioxidant and Anti-Inflammatory Activity of Fermented Milks with Exopolysaccharides-Producing Lactiplantibacillus plantarum Strains

Exopolysaccharides (EPSs) producing lactic acid bacteria have been claimed to confer various health benefits to the host, including the ability to face oxidative and inflammatory-related stress. This study investigated the ability of food-borne Lactiplantibacillus (Lpb.) plantarum to improve the antioxidant activity of fermented milks by producing EPSs. Two Lpb. plantarum strains, selected as lower and higher EPSs producers, have been applied in lab-scale fermented milk production, in combination with conventional starters. Antioxidant activity was investigated in vitro using DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and FRAP (ferric reducing antioxidant power) assays while the ability to modulate reactive oxygen species (ROS) level was evaluated in an intestinal healthy model, subjected to both oxidative and inflammatory stress. Furthermore, to verify whether digestion affects functionality, fermented milks were evaluated before and after in vitro-simulated INFOGEST digestion. The results showed an improved antioxidant activity of fermented milk enriched with Lpb. plantarum LT100, the highest EPSs producer. Furthermore, the data showed a different ROS modulation with a protective anti-inflammatory effect of samples enriched with Lpb. plantarum strains. Our data suggest the use of selected EPS-producing strains of Lpb. plantarum as a natural strategy to enrich the functionality of fermented milks in terms of ROS modulation and inflammatory-related stress.

Microbial dysbiosis and the aging process: a review on the potential age-deceleration role of Lactiplantibacillus plantarum

Gut microbiota dysbiosis has been a serious risk factor for several gastric and systemic diseases. Recently, gut microbiota's role in aging was discussed. Available preclinical evidence suggests that the probiotic bacteria Lactiplantibacillus plantarums (LP) may influence the aging process via modulation of the gut microbiota. The present review summarized compelling evidence of LP's potential effect on aging hallmarks such as oxidative stress, inflammation, DNA methylation, and mitochondrial dysfunction. LP gavage modulates gut microbiota and improves overall endurance in aging animal models. LP cell constituents exert considerable antioxidant potential which may reduce ROS levels directly. In addition, restored gut microbiota facilitate a healthy intestinal milieu and accelerate multi-channel communication via signaling factors such as SCFA and GABA. Signaling factors further activate specific transcription factor Nrf2 in order to reduce oxidative damage. Nrf2 regulates cellular defense systems involving anti-inflammatory cytokines, MMPs, and protective enzymes against MAPKs. We concluded that LP supplementation may be an effective approach to managing aging and associated health risks.

Antitumor effect of exopolysaccharide from Lactiplantibacillus plantarum WLPL09 on melanoma mice via regulating immunity and gut microbiota

Exopolysaccharide (EPS-09) from L. plantarum WLPL09 was systemically investigated for the antitumor effect in B16F10 melanoma bearing mice model. The results showed that administraion of EPS-09 (200 mg/kg) could sigificantly inhibit the tumor growth of melanoma bearing mice, with a inhibition rate of 42.53 %. Meanwhile, compared to the Model group, high dose of EPS-09 (200 mg/kg) administraion could increase the spleen index (P = 0.10), promote the splenic lymphocytes proliferation under the stimulation of ConA and LPS with a proliferation rate of 120.58 % and 169.88 %, respectively, enhance the amount of CD4+ and CD8+ T cells (P < 0.0001, P = 0.0149) in tumor tissue, as well as the serum content of cytokines, i.e., TNF-α, IFN-γ, IL-2 (P < 0.05) and IL-6 (P = 0.039) of B16F10 melanoma bearing mice. The transcriptional level analysis revealed that EPS-09 (200 mg/kg) administraion could sigificantly (P < 0.05) upregulate the transcription of apoptosis raleted genes, i.e., P53, Caspase-3 and Caspase-9, and the ratio of Bax/Bcl-2, downregulate the transcription of angiogenesis markers, i.e., Vegf and Fgf2 compared with Model group. Furthermore, administration of EPS-09 could increase the abundance of phylum Firmicutes, family Ruminococcaceae and Lachnospiraceae, and genus Ruminococcus, but reduce the abundance of genus Prevotella, Akkermansia and Oscillospira. Taken together, these results indicate that administration of EPS-09 can induce apoptosis of tumor cell, inhibit tumor angiogenesis, improve the immunity, regulate the intestinal microbiota composition of B16F10 melanoma bearing mice, and play positive roles in the antitumor activity against melanoma.

Effects of tandem fermentation of edible mushroom and L. plantarum on sensory, polysaccharide, vitamin C, and γ-aminobutyric acid of Rosa roxburghii Tratt and coix seed beverage

A new Rosa roxburghii Tratt (RRT) and coix seed (CS) beverage rich in multi-active ingredients was developed. Edible mushrooms and L. plantarum were selected for fermentation in stages. Some physicochemical properties, γ-aminobutyric acid (GABA), polysaccharides and sensory were studied during the T. versicolor and L. plantarum fermentation. T. versicolor increased the free amino acid through enzymatic protein digestion in the early growth stage and used these amino acids to synthesize its bacteriophage protein. T. versicolor and L. plantarum increased the polysaccharide and GABA of the fermentation broth. Vitamin C was retained as much as possible, with a slight loss occurring mainly in the aerobic fermentation stage of T. versicolor. Its less loss in exchange was for a higher value of T. versicolor polysaccharide, protein enhancement, and bitterness reduction. This study provides a reference for the deep processing of Guizhou's unique agricultural products and edible mushroom fermented beverage.

Lactic Acid Bacteria-Derived Exopolysaccharides Mitigate the Oxidative Response via the NRF2-KEAP1 Pathway in PC12 Cells

Parabiotics, including L-EPSs, have been administered to patients with neurodegenerative disorders. However, the antioxidant properties of L-EPSs against H2O2-induced oxidative stress in PC12 cells have not been studied. Herein, we aimed to investigate the antioxidant properties of the L-EPSs, their plausible targets, and their mechanism of action. We first determined the amount of L-EPSs in Lactobacillus delbrueckii ssp. bulgaricus B3 and Lactiplantibacillus plantarum GD2 using spectrophotometry. Afterwards, we studied their effects on TDH, TOS/TAS, antioxidant enzyme activities, and intracellular ROS level. Finally, we used qRT-PCR and ELISA to determine the effects of L-EPSs on the NRF2-KEAP1 pathway. According to our results, the L-EPS groups exhibited significantly higher total thiol activity, native thiol activity, disulfide activity, TAS levels, antioxidant enzyme levels, and gene expression levels (GCLC, HO-1, NRF2, and NQO1) than did the H2O2 group. Additionally, the L-EPS groups caused significant reductions in TOS levels and KEAP1 gene expression levels compared with those in the H2O2 group. Our results indicate that H2O2-induced oxidative stress was modified by L-EPSs. Thus, we revealed that L-EPSs, which regulate H2O2-induced oxidative stress, could have applications in the field of neurochemistry.

Multi-Faceted Bioactivity Assessment of an Exopolysaccharide from Limosilactobacillus fermentum NCDC400: Antioxidant, Antibacterial, and Immunomodulatory Proficiencies

Exopolysaccharides (EPS) are acknowledged for their diverse functional and technological properties. This study presents the characterization of EPS400, an acidic exopolysaccharide sourced from the native probiotic Limosilactobacillus fermentum NCDC400. Notably, this strain has demonstrated previous capabilities in enhancing dairy food texture and displaying in vivo hypocholesterolemic activity. Our investigation aimed to unveil EPS400's potential biological roles, encompassing antioxidant, antibacterial, and immunomodulatory activities. The results underscore EPS400's prowess in scavenging radicals, including the 2,2-diphenyl-1-picrylhydrazyl radical, 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid) radical, superoxide radical, hydroxyl radical, and chelating activity targeting the ferrous ion. Furthermore, EPS400 displayed substantial antibacterial effectiveness against prevalent food spoilage bacteria such as Pseudomonas aeruginosa NCDC105 and Micrococcus luteus. Remarkably, EPS400 exhibited the ability to modulate cytokine production, downregulating pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and nitric oxide, while concurrently promoting the release of anti-inflammatory cytokine IL-10 within lipopolysaccharide-activated murine primary macrophages. Additionally, EPS400 significantly (p ≤ 0.05) enhanced the phagocytic potential of macrophages. Collectively, our findings spotlight EPS400 as a promising contender endowed with significant antioxidant, antibacterial, and immunomodulatory attributes. These characteristics propose EPS400 as a potential pharmaceutical or bioactive component, with potential applications in the realm of functional food development.

Novel Kefir Exopolysaccharides (KEPS) Mitigate Lipopolysaccharide (LPS)-Induced Systemic Inflammation in Luciferase Transgenic Mice through Inhibition of the NF-κB Pathway

A novel kefir exopolysaccharides (KEPS) derived from kefir grain fermentation were found to have a small molecular weight (12 kDa) compared to the traditionally high molecular weight (12,000 kDa) of kefiran (KE). KE has been shown to possess antioxidant, blood pressure-lowering, and immune-modulating effects. In this study, we characterized KEPS and KE and evaluated their anti-inflammatory properties in vitro using RAW264.7 macrophages. The main monosaccharide components were identified as glucose (98.1 ± 0.06%) in KEPS and galactose (45.36 ± 0.16%) and glucose (47.13 ± 0.06%) in KE, respectively. Both KEPS and KE significantly reduced IL-6 secretion in lipopolysaccharide (LPS)-stimulated macrophages. We further investigated their effects in LPS-induced systemic injury in male and female NF-κB-luciferase+/+ transgenic mice. Mice received oral KEPS (100 mg/kg) or KE (100 mg/kg) for seven days, followed by LPS or saline injection. KEPS and KE inhibited NF-κB signaling, as indicated by reduced luciferase expression and phosphorylated NF-κB levels. LPS-induced systemic injury increased luciferase signals, especially in the kidney, spleen, pancreas, lung, and gut tissues of female mice compared to male mice. Additionally, it upregulated inflammatory mediators in these organs. However, KEPS and KE effectively suppressed the expression of inflammatory mediators, including p-MAPK and IL-6. These findings demonstrate that KEPS can alleviate LPS-induced systemic damage by inhibiting NF-κB/MAPK signaling, suggesting their potential as a treatment for inflammatory disorders.

Whole Genome Sequence of Lactiplantibacillus plantarum HOM3204 and Its Antioxidant Effect on D-Galactose-Induced Aging in Mice

Lactiplantibacillus plantarum, previously named Lactobacillus plantarum, is a facultative, homofermentative lactic acid bacterium widely distributed in nature. Several Lpb. plantarum strains have been demonstrated to possess good probiotic properties, and Lpb. plantarum HOM3204 is a potential probiotic strain isolated from homemade pickled cabbage plants. In this study, whole-genome sequencing was performed to acquire genetic information and predict the function of HOM3204, which has a circular chromosome of 3,232,697 bp and two plasmids of 48,573 and 17,060 bp, respectively. Moreover, various oxidative stress-related genes were identified in the strain, and its antioxidant activity was evaluated in vitro and in vivo. Compared to reference strains, the intracellular cell-free extracts of Lpb. plantarum HOM3204 at a dose of 1010 colony-forming units (CFU)/ml in vitro exhibited stronger antioxidant properties, such as total antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl radical scavenging rate, superoxide dismutase activity, and glutathione (GSH) content. Daily administration of 109 CFU Lpb. plantarum HOM3204 for 45 days significantly improved the antioxidant function by increasing the glutathione peroxidase activity in the whole blood and GSH concentration in the livers of D-galactose-induced aging mice. These results suggest that Lpb. plantarum HOM3204 can potentially be used as a food ingredient with good antioxidant properties.

Aged gut microbiota contribute to different changes in antioxidant defense in the heart and liver after transfer to germ-free mice

Age-associated impairment in antioxidant defense is an important cause of oxidative stress, and elderly individuals are usually associated with gut microbiota (GM) changes. Studies have suggested a potential relationship between the GM and changes in antioxidant defense in aging animals. Direct evidence regarding the impact of aging-associated shifts in GM on the antioxidant defense is lacking. The heart is a kind of postmitotic tissue, which is more prone to oxidative stress than the liver (mitotic tissue). To test and compare the influence of an aged GM on antioxidant defense changes in the heart and liver of the host, in this study, GM from young adolescent (5 weeks) or aged (20 months) mice was transferred to young adolescent (5 weeks) germ-free (GF) mice (N = 5 per group) by fecal microbiota transplantation (FMT). Four weeks after the first FMT was performed, fecal samples were collected for 16S rRNA sequencing. Blood, heart and liver samples were harvested for oxidative stress marker and antioxidant defense analysis. The results showed that mice that received young or aged microbiota showed clear differences in GM composition and diversity. Mice that received aged microbiota had a lower ratio of Bacteroidetes/Firmicutes in GM at the phylum level and an increased relative abundance of four GM genera: Akkermansia, Dubosiella, Alistipes and Rikenellaceae_RC9_gut_group. In addition, GM α-diversity scores based on the Shannon index and Simpson index were significantly higher in aged GM-treated mice. Oxidative stress marker and antioxidant defense tests showed that FMT from aged donors did not have a significant influence on malondialdehyde content in serum, heart and liver. However, the capacity of anti-hydroxyl radicals in the heart and liver, as well as the capacity of anti-superoxide anions in the liver, were significantly increased in mice with aged microbiota. FMT from aged donors increased the activities of Cu/Zn superoxide SOD (Cu/Zn-SOD), catalase (CAT) and glutathione-S-transferase in the heart, as well as the activity of Cu/Zn-SOD in the liver. Positive correlations were found between Cu/Zn-SOD activity and radical scavenging capacities. On the other hand, glutathione reductase activity and glutathione content in the liver were decreased in mice that received aged GM. These findings suggest that aged GM transplantation from hosts is sufficient to influence the antioxidant defense system of young adolescent recipients in an organ-dependent manner, which highlights the importance of the GM in the aging process of the host.

In Vivo Functional Properties of Dairy Bacteria

This literature review aimed to collect investigations on the in vivo evidence for bacteria associated with fermented dairy foods to behave as probiotics with beneficial effects in the prevention and treatment of various diseases. All main bacterial groups commonly present in high numbers in fermented milks or cheeses were taken into account, namely starter lactic acid bacteria (SLAB) Lactobacillus delbrueckii subsp. bulgaricus and lactis, L. helveticus, Lactococcus lactis, Streptococcus thermophilus, non-starter LAB (NSLAB) Lacticaseibacillus spp., Lactiplantibacillus plantarum, dairy propionibacteria, and other less frequently encountered species. Only studies regarding strains of proven dairy origin were considered. Studies in animal models and clinical studies showed that dairy bacteria ameliorate symptoms of inflammatory bowel disease (IBD), mucositis, metabolic syndrome, aging and oxidative stress, cancer, bone diseases, atopic dermatitis, allergies, infections and damage caused by pollutants, mild stress, and depression. Immunomodulation and changes in the intestinal microbiota were the mechanisms most often involved in the observed effects. The results of the studies considered indicated that milk and dairy products are a rich source of beneficial bacteria that should be further exploited to the advantage of human and animal health.

Effects of microbial-derived biotics (meta/pharma/post-biotics) on the modulation of gut microbiome and metabolome; general aspects and emerging trends

Potential effects of metabiotics (probiotics effector molecules or signaling factors), pharmabiotics (pro-functional metabolites produced by gut microbiota (GMB)) and postbiotics (multifunctional metabolites and structural compounds of food-grade microorganisms) on GMB have been rarely reviewed. These multifunctional components have several promising capabilities for prevention, alleviation and treatment of some diseases or disorders. Correlations between these essential biotics and GMB are also very interesting and important in human health and nutrition. Furthermore, these natural bioactives are involved in modulation of the immune function, control of metabolic dysbiosis and regulation of the signaling pathways. This review discusses the potential of meta/pharma/post-biotics as new classes of pharmaceutical agents and their effective mechanisms associated with GMB-host cell to cell communications with therapeutic benefits which are important in balance and the integrity of the host microbiome. In addition, cutting-edge findings about bioinformatics /metabolomics analyses related to GMB and these essential biotics are reviewed.

High Antioxidant Capacity of Lacticaseibacillus paracasei TDM-2 and Pediococcus pentosaceus TCM-3 from Qinghai Tibetan Plateau and Their Function towards Gut Modulation

Probiotic supplementation is a key therapeutic strategy for promoting gut health and maintaining gut homeostasis by modulating functional microbiota. In this study, we isolated two lactic acid bacteria (LAB) strains, Pediococcus pentosaceus TCM-3 and Lacticaseibacillus paracasei TDM-2, from Qinghai-Tibetan plateau, and evaluated their probiotic properties and antioxidant bioactivity. In which, TDM-2 had higher T-AOC activity than either TCM-3 or LGG (4.10 μmol/mL vs. 3.68 and 3.53 μmol/mL, respectively, p < 0.05). These strains have shown high antioxidant activity compared to the LAB strains and were found to be acid and bile salt tolerant, confronting the safety issues of antibiotic resistance and the capability of surviving in simulated gastric and intestinal juices. In vitro fermentation experiments with human gut microbiota revealed significant differences in microbial community composition between samples supplemented with TCM-3 and TDM-2 and those without. The addition of these two strains resulted in an enrichment of beneficial taxa, such as the Pediococcus, Lactobacillus, and Clostridium_sensu_strictos at the genus level, and Firmicutes and Proteobacteria at the phylum level. Notably, the TCM-3 group exhibited higher short-chain fatty acid production than the TDM-2 group and untreated controls (acetic acid at 12 h: 4.54 mmol L^-1 vs. 4.06 mmol L^-1 and 4.00 mmol L^-1; acetic acid at 24 h: 4.99 mmol L^-1 vs. 4.90 mmol L^-1 and 4.82 mmol L^-1, p < 0.05). These findings demonstrate that LAB supplementation with high antioxidant capacity and probiotic properties can promote gut health by modulating functional microbiota and is enriching for beneficial taxa. Our study provides guidance for therapeutic strategies that use novel LAB strains to maintain gut homeostasis and functional microbiota modulation.

Biological activities and applications of exopolysaccharides produced by lactic acid bacteria: a mini-review

Exopolysaccharides (EPSs) are naturally occurring high-molecular-weight carbohydrates that have been widely studied for their biological activities, including antioxidant, immunomodulatory, anticancer and gut microbiota regulation activities. Polysaccharides are abundant in nature and can be derived from animals, plants, algae, and microorganisms, but among polysaccharides with potential uses, EPSs from microorganisms have the advantages of a short production cycle, high yield, and independence of production from season and climate and thus have broad prospects. While the safety of the producing microorganism can represent a problem in application of microbial EPSs, lactic acid bacteria (LAB) have been used by humans for thousands of years, and they and their products are generally recognized as safe. This makes LAB excellent sources for exopolysaccharides. EPS-producing LAB are readily found in nature. Through screening of strains, optimization of culture conditions, and improvement of the growth medium, the yield of EPSs from LAB can be increased and the scope of application broadened. This review summarizes EPSs from LAB in terms of structure, function and applications, as well as yield optimization, and introduces recent research on the biological activities and practical applications of LAB EPSs, aiming to provide references for researchers in related areas.

Exopolysaccharides from lactic acid bacteria, as an alternative to antibiotics, on regulation of intestinal health and the immune system

Over-use or misuse of antibiotics in livestock and poultry production contributes to the rising threat of antibiotic resistance in animals and has negative ecological effects. Exopolysaccharides from lactic acid bacteria (LAB-EPS) are a class of biological macromolecules which are secreted by lactic acid bacteria to the outside of the cell wall during their growth and metabolism. Numerous studies demonstrated that LAB-EPS have anti-inflammatory and antimicrobial activities and are able to regulate intestinal health and the immune system in livestock. They are biodegradable, nontoxic and bio-compatible, which are considered as ideal alternatives to antibiotics. This review aims to discuss and summarize recent research findings of LAB-EPS on regulation of intestinal health and the immune system in animals, and thus provide scientific justification for commercial applications of LAB-EPS in livestock.

Fermented Angelica sinensis activates Nrf2 signaling and modulates the gut microbiota composition and metabolism to attenuate D-gal induced liver aging

Aging is an inevitable physiological process associated with an imbalance in the oxidative defense system. Angelica sinensis, a kind of traditional Chinese medicine (TCM), has anti-oxidant effects and has been considered as a potential supplement in anti-aging treatment. Nevertheless, it has the disadvantages of slow efficacy and long duration of treatment. Fermentation, as an efficient biotechnological approach, is beneficial for improving the nutritional capacity of the material. Fermented TCMs are considered to be more effective. In this study, fermented Angelica sinensis (FAS) and non-fermented Angelica sinensis (NFAS) were used to investigate changes in the chemical constituents. Furthermore, the improvement effect of FAS on D-galactose-induced aging in mice and the potential mechanisms were explored. The results revealed that FAS and NFAS had different constituents under the influence of fermentation, such as 3-phenyllactic acid, L-5-hydroxytryptophan, taxifolin and methyl gallate. These elevated constituents of FAS might help increase the ability of FAS to improve aging. The aging model was established by intraperitoneal injection of D-galactose (2.5 g kg^-1 day^-1) for 44 days, and FAS (3 g kg^-1 day^-1) was administered daily by oral gavage after 2 weeks of induction with D-galactose. FAS was observed to significantly ameliorate changes associated with liver aging, such as reduction of MDA, AGEs and 8-OHdG. The contents of pro-inflammatory cytokines containing TNF-α, IL-1β and IL-6 were significantly suppressed in the FAS group. In addition, FAS activated Nrf2 signaling better than NFAS, improved the expression of Nrf2, HO-1, NQO1, GCLC, GCLM and GSS, and further increased the activities of SOD, CAT and other antioxidant enzymes in the liver. Simultaneously, it had a certain repair effect on the liver tissues of mice. The intestinal microbiota analysis showed that FAS could regulate the microbiota imbalance caused by aging, increase the ratio of Firmicutes/Bacteroidetes by 95% and improve the relative abundance of beneficial bacteria related to Nrf2 signaling, such as Lactobacillus. Besides, fecal metabolite analysis identified uric acid as an evidential metabolite, suggesting that FAS participates in purine metabolism to improve aging. Therefore, the regulation of intestinal microbiota and metabolism may be one of the important mechanisms of FAS in alleviating hepatic oxidative stress via the gut-liver axis. The results of this study could provide information for the future development of postbiotic products that may have beneficial effects on the prevention or treatment of aging.

Lacticaseibacillus rhamnosus-Derived Exopolysaccharide Attenuates D-Galactose-Induced Oxidative Stress and Inflammatory Brain Injury and Modulates Gut Microbiota in a Mouse Model

This study aimed to investigate the protective effect of a novel exopolysaccharide EPSRam12, produced by Lacticaseibacillus rhamnosus Ram12, against D-galactose-induced brain injury and gut microbiota dysbiosis in mice. The findings demonstrate that EPSRam12 increases the level of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase, total antioxidant capacity, and the level of anti-inflammatory cytokine IL-10, while decreasing malonaldehyde, nitric oxide, pro-inflammatory cytokines including TNF-α, IL-1β, IL-6, MCP-1, and the mRNA expression of cyclooxygenase-2, inducible nitric oxide synthase, and the activation of nuclear factor-kappa-B in the brain tissues of D-galactose-treated mice. Further analyses reveal that EPSRam12 improves gut mucosal barrier function and increases the levels of short-chain fatty acids (SCFAs) in the intestine while restoring gut microbial diversity by enriching the abundance of SCFA-producing microbial genera Prevotella, Clostridium, Intestinimonas, and Acetatifactor while decreasing potential pathobionts including Helicobacter. These findings of antioxidative and anti-inflammatory effects in the brain and ameliorative effects on epithelial integrity, SCFAs and microbiota in the gut, provide novel insights into the effect of EPSRam12 intervention on the gut–microbiome–brain axis and should facilitate prospective understanding of microbial exopolysaccharide for improved host health.

Resveratrol Alleviating the Ovarian Function Under Oxidative Stress by Alternating Microbiota Related Tryptophan-Kynurenine Pathway

Oxidative stress (OS) is a key factor regulating the systemic pathophysiological effects and one of the fundamental mechanisms associated with aging and fertility deterioration. Previous studies revealed that resveratrol (RV) exhibits a preventive effect against oxidative stress in the ovary. However, it remains unknown whether gut microbiota respond to resveratrol during an OS challenge. In Exp. 1, layers received intraperitoneal injection of tert-butyl hydroperoxide (tBHP) (0 or 800 μmol/kg BW) or received resveratrol diets (0 or 600 mg/kg) for 28 days. In Exp. 2, the role of intestinal microbiota on the effects of resveratrol on tBHP-induced oxidative stress was assessed through fecal microbiota transplantation (FMT). The OS challenge reduced the egg-laying rate and exhibited lower pre-hierarchical follicles and higher atretic follicles. Oral RV supplementation ameliorated the egg-laying rate reduction and gut microbiota dysbiosis. RV also reversed the tryptphan-kynurenine pathway, upregulated nuclear factor E2-related factor 2 (Nrf2) and silent information regulator 1(SIRT1) levels, and decreased the expression of forkhead box O1 (FoxO1) and P53. These findings indicated that the intestinal microbiota-related tryptophan-kynurenine pathway is involved in the resveratrol-induced amelioration of ovary oxidative stress induced by tBHP in the layer model, while SIRT1-P53/FoxO1 and Nrf2-ARE signaling pathway were involved in this process.

Effect of Chilled Storage on Antioxidant Capacities and Volatile Flavors of Synbiotic Yogurt Made with Probiotic Yeast Saccharomyces boulardii CNCM I-745 in Combination with Inulin

Fermentation of available sugars in milk by yogurt starter culture initially and later by Saccharomyces boulardii (Probiotic yeast) improves the bioavailability of nutrients and produces bioactive substances and volatile compounds that enhance consumer acceptability. The combination of S. boulardii, a unique species of probiotic yeast, and inulin, an exopolysaccharide used as a prebiotic, showed remarkable probiotic and hydrocolloid properties in dairy products. The present study was designed to study the effect of fermentation and storage on antioxidant and volatile capacities of probiotic and synbiotic yogurt by incorporation of S. boulardii and inulin at 1%, 1.5%, and 2% (w/v), compared with the probiotic and control plain yogurt. All samples were stored at 4 °C, and during these four weeks, they were analyzed in terms of their antioxidant and volatile compounds. The synbiotic yogurt samples having inulin and S. boulardii displayed significantly higher DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical activity values and more values of TPC (total phenol contents) than control plain yogurt. A total of 16 volatile compounds were identified in S5-syn2 and S4-syn1.5, while S3-syn1 and S2-P had 14, compared with the control S1-C plain yogurt samples, which had only 6. The number of volatile compounds increased with the increasing concentration of inulin throughout the storage period. Therefore, this novel synbiotic yogurt with higher antioxidant and volatile compounds, even with chilling storage conditions, will be a good choice for consumer acceptability.

Lactobacillus Plantarum-derived extracellular vesicles protect against ischemic brain injury via the microRNA-101a-3p/c-Fos/TGF-β axis

Currently, the reported source of extracellular vesicles (EVs) for the treatment of ischemic stroke（IS）is limited to mammals. Moreover, these EVs are restricted to clinical translation by the high cost of cell culture. In this respect, Lactobacillus Plantarum culture is advantaged by low cost and high yield. However, it is poorly understood whether Lactobacillus Plantarum-derived EVs (LEVs) are applicable for the treatment of IS. Here, our results demonstrated that LEVs reduced apoptosis in ischemic neuron both in vivo and in vitro. As revealed by high-throughput sequencing, miR-101a-3p expression was significantly elevated by LEV treatment in OGD/R-induced neurons, as confirmed in the tMCAO mice treated with LEVs. Mechanistically, c-Fos was directly targeted by miR-101a-3p. In addition, c-Fos determined ischemia-induced neuron apoptosis in vivo and in vitro through the TGF-β1 pathway, miR-101a-3p inhibition aggravated ischemia-induced neuron apoptosis in vitro and in vivo, and miR-101a-3p overexpression produced the opposite results. Hsa-miR-101-3p was downregulated in the plasma of patients with IS but upregulated in the patients with neurological recovery after rt-PA intravenous thrombolysis. In conclusion, Our results demonstrated for the first time that LEVs might inhibit neuron apoptosis via the miR-101a-3p/c-Fos/TGF-β axis, and has-miR-101-3p is a potential marker of neurological recovery in IS patients.

The Emerging Role of the Aging Process and Exercise Training on the Crosstalk between Gut Microbiota and Telomere Length

Aging is a natural process of organism deterioration, which possibly impairs multiple physiological functions. These harmful effects are linked to an accumulation of somatic mutations, oxidative stress, low-grade inflammation, protein damage, and mitochondrial dysfunction. It is known that these factors are capable of inducing telomere shortening, as well as intestinal dysbiosis. Otherwise, among the biological mechanisms triggered by physical exercise, the attenuation of pro-inflammatory mediators accompanied by redox state improvement can be the main mediators for microbiota homeostasis and telomere wear prevention. Thus, this review highlights how oxidative stress, inflammation, telomere attrition, and gut microbiota (GM) dysbiosis are interconnected. Above all, we provide a logical foundation for unraveling the role of physical exercise in this process. Based on the studies summarized in this article, exercise training can increase the biodiversity of beneficial microbial species, decrease low-grade inflammation and improve oxidative metabolism, these factors together possibly reduce telomeric shortening.

Structure characterization, antioxidant and emulsifying capacities of exopolysaccharide derived from Tetragenococcus halophilus SNTH-8

Tetragenococcus halophilus exopolysaccharides (THPS) are metabolites released by T. halophilus SNTH-8 to resist a high-salt environment. Although many studies have investigated the mechanisms underlying salt tolerance shown by T. halophilus, structural characteristics as well as antioxidant and emulsifying capacities of THPS remain unclear. In this study, we isolated and purified two components, THPS-1 and THPS-2, from T. halophilus SNTH-8. Purified THPS-1 and THPS-2 were composed of arabinose, xylose, fucose, galactose, glucose, and glucuronic acid at a molar ratio of 1.66:38.95:2.11:26.12:29.73:1.43 and 0.46:40.3:0.54:30.8:1.36:25.54, respectively. The average molecular weights of THPS-1 and THPS-2 were 14.98 kDa and 21.03 kDa, respectively. Moreover, the structures of THPS-1 and THPS-2 were investigated via fourier-transform infrared spectroscopy(FT-IR), nuclear magnetic resonance spectroscopy(NMR), scanning electron microscopy(SEM), and methylation analysis. THPS-1 was a highly branched polysaccharide with a backbone of α-D-(1,4)-Xyl, α-D-(1,6)-Glc and α-D-Xyl as the terminal, while THPS-2 was a highly branched polysaccharide with a backbone of α-D-(1,4)-Xyl and β-D-GlcA as the terminal. The branches were identified as β-D-(1,4,6)-Gal and β-D-(1,6)-Gal. Both THPS-1 and THPS-2 exhibited high antioxidant and emulsifying capacities. Overall, our structural analysis of THPS may further enhance research on natural emulsifiers and antioxidants.

Balancing reactive oxygen species generation by rebooting gut microbiota

Reactive oxygen species (ROS; free radical form O₂ ^•‾ , superoxide radical; OH^• , hydroxyl radical; ROO^• , peroxyl; RO^• , alkoxyl and non-radical form ¹ O₂ , singlet oxygen; H₂ O₂ , hydrogen peroxide) are inevitable companions of aerobic life with crucial role in gut health. But, overwhelming production of ROS can cause serious damage to biomolecules. In this review, we have discussed several sources of ROS production that can be beneficial or dangerous to the human gut. Microorganisms, organelles and enzymes play crucial role in ROS generation, where, NOX1 is the main intestinal enzyme, which produce ROS in the intestine epithelial cells. Previous studies have reported that probiotics play significant role in gut homeostasis by checking the ROS generation, maintaining the antioxidant level, immune system and barrier protection. With current knowledge, we have critically analyzed the available literature and presented the outcome in the form of bubble maps to suggest the probiotics that help in controlling the ROS-specific intestinal diseases, such as inflammatory bowel disease (IBD) and colon cancer. Finally, it has been concluded that rebooting of the gut microbiota with probiotics, postbiotics or fecal microbiota transplantation (FMT) can have crucial implications in the structuring of gut communities for the personalized management of the gastrointestinal (GI) diseases.

Effects of Exopolysaccharides from Lactiplantibacillus plantarum JLAU103 on Intestinal Immune Response, Oxidative Stress, and Microbial Communities in Cyclophosphamide-Induced Immunosuppressed Mice

This study investigated the effects of the exopolysaccharide from Lactiplantibacillus plantarum JLAU103 (EPS103) on the intestinal immune response, oxidative stress, intestinal mucosal barrier, and microbial community in cyclophosphamide-induced immune-suppressed mice. The results showed that EPS103 promoted the secretion of cytokines and the generation of secretory immunoglobulin A and mucin-2 in the small intestine of mice, which might be related to the activation of the MAPK pathway. Additionally, EPS103 protected against oxidative stress by activating antioxidation enzymes and Nrf2/Keap1 pathways. It also improved the intestinal physical barrier functions via regulating the ratio of villous height to crypt depth and upregulating the expression of tight-junction proteins. Meanwhile, EPS103 promoted the generation of short-chain fatty acids (SCFAs) and modulated the constituents of gut microbiota. These results suggested that EPS103 may modulate the intestinal immunoresponse relying on the regulation of SCFA production and gut microbiota in immunosuppressed mice, resulting in the activation of systemic immunity.

Advancements in the Use of Fermented Fruit Juices by Lactic Acid Bacteria as Functional Foods: Prospects and Challenges of Lactiplantibacillus (Lpb.) plantarum subsp. plantarum Application

Lactic acid fermentation of fresh fruit juices is a low-cost and sustainable process, that aims to preserve and even enhance the organoleptic and nutritional features of the raw matrices and extend their shelf life. Selected Lactic Acid Bacteria (LAB) were evaluated in the fermentation of various fruit juices, leading in some cases to fruit beverages, with enhanced nutritional and sensorial characteristics. Among LAB, Lactiplantibacillus (Lpb.) plantarum subsp. plantarum strains are quite interesting, regarding their application in the fermentation of a broad range of plant-derived substrates, such as vegetables and fruit juices, since they have genome plasticity and high versatility and flexibility. L. plantarum exhibits a remarkable portfolio of enzymes that make it very important and multi-functional in fruit juice fermentations. Therefore, L. plantarum has the potential for the production of various bioactive compounds, which enhance the nutritional value and the shelf life of the final product. In addition, L. plantarum can positively modify the flavor of fruit juices, leading to higher content of desirable volatile compounds. All these features are sought in the frame of this review, aiming at the potential and challenges of L. plantarum applications in the fermentation of fruit juices.

The Microbial Diversity and Biofilm-Forming Characteristic of Two Traditional Tibetan Kefir Grains

In this study, a high-throughput sequencing technique was used to analyze bacterial and fungal diversity of two traditional Tibetan kefir grains from Linzhi (K1) and Naqu (K2) regions. Comparative bioinformatic analyses indicated that Lactobacillus kefiranofaciens, L. kefiri and Kluyveromyces marxianus were the main dominant strains in K1 and K2. In order to research the relationship of the growth of kefir grains, the biofilm and the extracellular polysaccharides (EPS) produced by microorganisms, the proliferation rate of kefir grains, the yield and chemical structure of EPS and the optimal days for biofilm formation were determined. The results showed that the growth rate, the yield of EPS and the biofilm formation ability of K1 were higher than K2, and the optimal day of their biofilm formation was the same in 10th day. Additionally, the live cells, dead cells and EPS in biofilm formation of K1 and K2 were observed by fluorescence microscope to clarify the formation process of kefir grains. To determine the influence of microbial interactions on biofilm and the formation of kefir grains, the essential role of microbial quorum sensing needs further attention.

Exopolysaccharides from a Scandinavian fermented milk viili increase butyric acid and Muribaculum members in the mouse gut

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Bioactivity of viili exopolysaccharide (VEPS) were determined in young male mice.

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Mice drank daily tap water supplemented with VEPS, stressless administration.

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A low dose VEPS modified mildly but significantly the gut microbiota.

Starter culture of viili contains lactic acid bacteria belonging to Lactococcus lactis. These bacteria secrete large polysaccharides (EPSs) into milk, resulting in a ropy texture of viili. In mouse experiments, a large dose of EPS (5–140 mg/day) has been shown to alleviate severity of artificially induced illness through modulation of the gut microbiota. The present study investigated whether supplementary amounts of EPS affects the gut microbiota of normal mouse. EPS with high glucosamine content (VEPS) was isolated from home-made viili. C57BL/6J male mice fed ordinary diet took 49 ± 1 μg VEPS/day for 28 days by drinking ad libitum tap water containing 8 μg/mL VEPS. The relative abundance of Muribaculum increased significantly by VEPS supplementation. The relative abundance of fecal butyric acid decreased in control mice, and VEPS prevented this decrease. These findings indicated that the gut microbiota can be modulated by a small dose of VEPS.

Bioactive Compounds from Kefir and Their Potential Benefits on Health: A Systematic Review and Meta-Analysis

Despite evidence of health benefits from kefir administration, a systematic review with meta-analysis on bioactive compounds associated with these benefits is still absent in the literature. Kefir is fermented milk resulting from the metabolism of a complex microbiota in symbiosis. Recent researches have investigated the bioactive compounds responsible for the preventive and therapeutic effects attributed to kefir. However, differences in functional potential between industrial and artisanal kefir are still controversial. Firstly, we identified differences in the microbial composition among both types of kefir. Available evidence concerning the action of different bioactive compounds from kefir on health, both from in vitro and in vivo studies, was subsequently summarized to draw a primary conclusion of the dose and the intervention time for effect, the producer microorganisms, the precursor in the milk, and the action mechanism. Meta-analysis was performed to investigate the statistically significant differences (P < 0.05) between intervention and control and between both types of kefir for each health effect studied. In summary, the bioactive compounds more commonly reported were exopolysaccharides, including kefiran, bioactive peptides, and organic acids, especially lactic acid. Kefir bioactive compounds presented antimicrobial, anticancer, and immune-modulatory activities corroborated by the meta-analysis. However, clinical evidence is urgently needed to strengthen the practical applicability of these bioactive compounds. The mechanisms of their action were diverse, indicating that they can act by different signaling pathways. Still, industrial and artisanal kefir may differ regarding functional potential-OR of 8.56 (95% CI: 2.27-32.21, P ≤ .001)-according to the observed health effect, which can be associated with differences in the microbial composition between both types of kefir.

Anti-Helicobacter pylori Activity of a Lactobacillus sp. PW-7 Exopolysaccharide

Helicobacter pylori is a cause of gastric cancer. We extracted the exopolysaccharide (EPS) of Lactobacillus plajomi PW-7 for antibacterial activity versus H. pylori, elucidating its biological activity and structural characteristics. The minimum inhibitory concentration (MIC) of EPS against H. pylori was 50 mg/mL. Disruption of the cell membranes of pathogenic bacteria by EPS was indicated via the antibacterial mechanism test and confirmed through electron microscopy. EPS also has antioxidant capacity. The IC₅₀ of EPS for 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical, superoxide anions, and hydroxyl radicals were 300 μg/mL, 180 μg/mL, and 10 mg/mL, respectively. The reducing power of EPS was 2 mg/mL, equivalent to 20 μg/mL of ascorbic acid. EPS is a heteropolysaccharide comprising six monosaccharides, with an approximate molecular weight of 2.33 × 10⁴ Da. Xylose had a significant effect on H. pylori. EPS from L. plajomi PW-7 showed potential as an antibacterial compound and antioxidant, laying a foundation for the development of EPS-based foods.

Antiaging Potential of Peptides from Underused Marine Bioresources

Aging is a biological process that occurs under normal conditions and in several chronic degenerative diseases. Bioactive natural peptides have been shown to improve the effects of aging in cell and animal models and in clinical trials. However, few reports delve into the enormous diversity of peptides from marine organisms. This review provides recent information on the antiaging potential of bioactive peptides from underused marine resources, including examples that scavenge free radicals in vitro, inhibit cell apoptosis, prolong the lifespan of fruit flies and Caenorhabditis elegans, suppress aging in mice, and exert protective roles in aging humans. The underlying molecular mechanisms involved, such as upregulation of oxidase activity, inhibition of cell apoptosis and MMP-1 expression, restoring mitochondrial function, and regulating intestinal homeostasis, are also summarized. This work will help highlight the antiaging potential of peptides from underused marine organisms which could be used as antiaging foods and cosmetic ingredients in the near future.

The Effect of Oxidative Stress on the Chicken Ovary: Involvement of Microbiota and Melatonin Interventions

The poultry ovary is used as a classic model to study ovarian biology and ovarian cancer. Stress factors induced oxidative stress to cause follicle atresia, which may be a fundamental reason for the reduction in fertility in older laying hens or in aging women. In the present study, we set out to characterize the relationships between oxidative stress and ovarian function. Layers (62 weeks of age; BW = 1.42 ± 0.12 kg) were injected with tert-butyl hydroperoxide (tBHP) at 0 (CON) and 800 μmol/kg BW (oxidative stress group, OS) for 24 days and the role of melatonin (Mel) on tBHP-induced ovary oxidative stress was assessed through ovary culture in vitro. The OS (800 μmol/kg BW tert-butyl hydroperoxide) treatment decreased the reproduction performance and ovarian follicle numbers. OS decreased the expression of SIRT1 and increased the P53 and FoxO1 expression of the ovary. A decreased Firmicutes to Bacteroidetes ratio, enriched Marinifilaceae (family), Odoribacter (genus) and Bacteroides_plebeius (species) were observed in the cecum of the OS group. Using Mel in vitro enhanced the follicle numbers and decreased the ovary cell apoptosis induced by tBHP. In addition, it increased the expression of SIRT1 and decreased the P53 and FoxO1 expression. These findings indicated that oxidative stress could decrease the laying performance, ovarian function and influence gut microbiota and body metabolites in the layer model, while the melatonin exerts an amelioration the ovary oxidative stress through SIRT1-P53/FoxO1 pathway.

Lactic Acid Bacteria Exopolysaccharides Producers: A Sustainable Tool for Functional Foods

Lactic acid bacteria (LAB) used in the food industry, mainly for the production of dairy products, are able to synthetize exopolysaccharides (EPS). EPS play a central role in the assessment of rheological and sensory characteristics of dairy products since they positively influence texture and organoleptic properties. Besides these, EPS have gained relevant interest for pharmacological and nutraceutical applications due to their biocompatibility, non-toxicity and biodegradability. These bioactive compounds may act as antioxidant, cholesterol-lowering, antimicrobial and prebiotic agents. This review provides an overview of exopolysaccharide-producing LAB, with an insight on the factors affecting EPS production, their dairy industrial applications and health benefits.

Effect of Different Kefir Source on Fermentation, Aerobic Stability, and Microbial Community of Alfalfa Silage

Simple Summary

Minimizing silage additives cost while increasing silage quality is important for a sustainable livestock enterprise, especially in undeveloped and developing countries. In this study, therefore, commercially available kefir yeast (CK) and homemade kefir culture (HK), as a low-cost additive, was applied at untreated a common control (CON) and three different application doses (5.0, 5.7, and 6.0 log cfu g⁻¹) on wilted alfalfa and evaluated with the fermentation characteristics and aerobic stability. The addition of HK with an application dose greater than 5.0 log cfu g⁻¹ prevents mold formation and inhibits yeast counts in silages. Indeed, both CK and HK improve the silage quality and aerobic stability of alfalfa even with low water-soluble carbohydrate content.

Abstract

The present study has been one of the first attempts to thoroughly examine the effects of different kefir sources on fermentation characteristics, aerobic stability, and microbial communities of alfalfa silages. The effects of commercial kefir (CK) and homemade kefir culture (HK) applied with untreated a common control (CON) and three different application doses (5.0, 5.7, and 6.0 log cfu g⁻¹) on wilted alfalfa and stored at an ambient temperature of 25–30 °C are studied. After 45 days of ensiling, fermentation characteristics and aerobic stability of silages were measured, and bacterial diversity was investigated by 16S ribosomal RNA gene sequencing using the GenomeLab™ GeXP platform. Both CK and HK accelerate more lactic acid production and reduced ammonia nitrogen concentration. Factor analysis of kefir sources suggests that the addition of kefir improves the aerobic stability of silages, even the initial water-soluble carbohydrate (WSC) content is inadequate via its antimicrobial effect on yeast and mold formation. Enterococcus faecium, Pediococcus pentosaceous and Lactobacillus brevis were dominant bacterial species among the treated groups at silo opening, while Lactobacillus plantarum and Lactobacillus brevis became dominant bacterial species after 7 days of aerobic exposure. In conclusion, the application of kefir on alfalfa silages improves fermentation quality and aerobic stability even with low WSC content.

Probiotics Fermentation Technology, a Novel Kefir Product, Ameliorates Cognitive Impairment in Streptozotocin-Induced Sporadic Alzheimer's Disease in Mice

Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive impairment. Gut microbiota dysfunction (dysbiosis) is implicated in the pathology of AD and is associated with several detrimental consequences, including neurotransmitter depletion, oxidative stress, inflammation, apoptosis, and insulin resistance, which all contribute to the onset of AD. The objective of this study was to assess the effectiveness of Probiotics Fermentation Technology (PFT), a kefir product, in alleviating AD symptoms via regulation of the gut microbiota using a streptozotocin- (STZ-) induced AD mouse model and to compare its activity with simvastatin, which has been proven to effectively treat AD. Mice received one intracerebroventricular injection of STZ (3 mg/kg). PFT (100, 300, 600 mg/kg) and simvastatin (20 mg/kg) were administered orally for 3 weeks. PFT supplementation mitigated STZ-induced neuronal degeneration in the cortex and hippocampus, restored hippocampal acetylcholine levels, and improved cognition in a dose-dependent manner. These effects were accompanied by reductions in oxidative damage, proinflammatory cytokine expression, apoptosis, and tau hyperphosphorylation. Moreover, PFT hindered amyloid plaque accumulation via the enhancement of insulin-degrading enzyme. These beneficial effects were comparable to those produced by simvastatin. The results suggest that PFT can alleviate AD symptoms by regulating the gut microbiota and by inhibiting AD-related pathological events.

Health-Promoting Properties of Lactobacilli in Fermented Dairy Products

Bacteria of the genus Lactobacillus have been employed in food fermentation for decades. Fermented dairy products, such as cheese and yogurt, are products of high value known as functional food and widely consumed due to their positive health impact. Fermentation was originally based on conversion of carbohydrate into organic acids, mostly lactic acid, intended to preserve nutrient in milk, but then it develops in other disclosure of capabilities associates with health benefit. It is expected that during the manufacture of fermented dairy products, some bioactive peptides from milk protein are released through proteolysis. Lactobacilli have been recognized and received increasing attention as probiotics by balancing gut microbial population. Information of molecular mechanisms of genome sequence focusing on the microbial that normally inhabit gut may explain as to how these bacteria positively give impact on improving host health. Recent post-biotics concept revealed that health benefit can also be associated after bacterial lysis. This mini review focuses on the contribution of lactobacilli in dairy fermentation with health-promoting properties on human health.

Interaction of the Exopolysaccharide from Lactobacillus plantarum YW11 with Casein and Bioactivities of the Polymer Complex

There has been an increased application of exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) in fermented dairy products, but interactions between EPS and casein (CAS), and bioactivities of their complex are poorly studied. In this study, EPS produced by Lactobacillus plantarum YW11 (EPS-YW11) was studied for interactions with CAS in a simulated fermentation system acidified by D-(+)-gluconic acid δ-lactone. The results showed that there was interaction between EPS-YW11 and CAS when EPS (up to 1%, w/v) was added to the casein solution (3%, w/v) as observed with increased viscoelasticity, water holding capacity, ζ-potential and particle size of EPS-YW11/CAS complex compared with CAS alone. Microstructural analysis showed that a higher concentration of EPS facilitated more even distribution of CAS particles that were connected through the polysaccharide chains. Infrared spectroscopy further confirmed interactions between EPS and CAS by intermolecular hydrogen bonding, electrostatic and hydrophobic contacts. Further evaluation of the bioactivities of EPS-YW11/CAS complex revealed significantly increased antibiofilm, antioxidation, and bile acids binding capacity. The present study provides further understanding on the mechanism of interactions between EPS produced by LAB and CAS, which would benefit potential applications of EPS in fermented dairy products with enhanced functionality.

Screening of folate-producing lactic acid bacteria and modulatory effects of folate-biofortified yogurt on gut dysbacteriosis of folate-deficient rats

Folate deficiency is accompanied by gut dysbacteriosis. To understand dietary intervention in folate deficiency, a folate-deficient rat model was used to evaluate the modulatory effects of folate-producing lactic acid bacteria (LAB) and biofortified yogurt on gut dysbacteriosis. The high folate-producing strain was screened from 12 LABs, and its variant, namely Lactobacillus plantarum GSLP-7 V, with folate productivity in yogurt at 3.72 μg mL-1, was obtained by stressing with 5.0 mg L-1 methotrexate and 100.00 mg L-1 Ca2+. To our knowledge, this is the highest folate productivity in yogurt by LAB strains ever reported. To further examine the folate supplement effect in vivo, a folate-deficient rat model was established and fed a folate-free diet for 8 weeks. Also, the effects of L. plantrum GSLP-7 V, yogurt fermented with L. plantrum GSLP-7 V, plain yogurt, and chemical folic acid on folate deficiency and gut dysbacteriosis were examined. Analysis of the change in gut microbiota showed that the gut dysbacteriosis was significantly correlated with folate deficiency. Administration of L. plantrum GSLP-7 V and its fermented yogurt for 10 days restored the disrupted gut microbiota and recovered the serum folate and homocysteine to normal levels, while chemical folic acid worsened the gut dysbacteriosis. Chemical folic acid only enriched Akkermansia, while L. plantrum GSLP-7 V and its fermented yogurt modulated the gut microbiota comprehensively through 7 and 10 key genera, respectively. This study confirmed the effectiveness of dietary intervention with folate-biofortified yogurt through modulating gut microbiota, suggesting the potential of the folate-producing LAB as an agent for the treatment of folate-deficiency related diseases.

Invited review: Effect of antihypertensive fermented milks on gut microbiota

Hypertension is a risk factor for the development of other cardiovascular diseases and remains one of the leading causes of death worldwide. Although genetic and environmental factors are associated with the development of hypertension, it has been recently recognized that gut microbiota (GM) may also have an effect on human health. In this sense, gut dysbiosis (a marked decrease in richness and diversity of GM) has been linked to different metabolic diseases, such as hypertension. Therefore, different studies have been pursued to reduce gut dysbiosis and diminish hypertension. Different strategies to maintain a balanced GM, particularly through diet and the use of probiotics, are being evaluated. Most recently, the effect of antihypertensive fermented milks on GM has been addressed. New evidence suggests that antihypertensive fermented milks may modulate GM. Thus, the aim of this review is to present available information related to the effect of antihypertensive fermented milks on gut microbiota.

Heat-Treated Bifidobacterium longum CECT-7347: A Whole-Cell Postbiotic with Antioxidant, Anti-Inflammatory, and Gut-Barrier Protection Properties

Non-viable preparations of probiotics, as whole-cell postbiotics, attract increasing interest because of their intrinsic technological stability, and their functional properties, such as immune system modulation, gut barrier maintenance, and protection against pathogens. However, reports on Bifidobacteria-derived postbiotics remain scarce. This study aims to demonstrate the functional properties of a heat-treated (HT), non-viable, Bifidobacterium longum strain, CECT-7347, a strain previously selected for its anti-inflammatory phenotype and ability to improve biomarkers of intestinal integrity in clinical trials. The study used the nematode Caenorhabditis elegans and HT-29 cell cultures as eukaryotic model systems. Our results show that HT-CECT-7347 preserves the capacity to protect against oxidative stress damage, while it also reduces acute inflammatory response and gut-barrier disruption, and inhibits bacterial colonization, by activating pathways related to innate immune function. These findings highlight the interest of the ingredient as a novel postbiotic and pave the way to broaden the range of HT-CECT-7347 applications in gut health.

In Vitro Modulatory Effect of Stevioside, as a Partial Sugar Replacer in Sweeteners, on Human Child Microbiota

The effect of stevioside on human health is still insufficiently highlighted by recent research. The total or partial replacement of sugar with sweeteners influences the general state of health, especially the human microbiota's response as a determining factor in the onset of type 2 diabetes. The present study aimed to present the long-term (one-year) in vitro effect that regular stevioside consumption had on children's pattern microbiota. A metabolomic response was established by determining the synthesis of organic acids and a correlation with antioxidant status. An increase in the number of bacterial strains and the variation of amount of butyrate and propionate to the detriment of lactic acid was observed. The effect was evidenced by the progressive pH increasing, the reduction of acetic acid, and the proliferation of Escherichia coli strains during the simulations. Synthesis of the main short-chain fatty acids (SCFAs) was interpreted as a response (adaptation) of the microbiota to the stevioside, without a corresponding increase in antioxidant status. This study demonstrated the modulatory role of stevioside on the human microbiota and on the fermentation processes that determine the essential SCFA synthesis in maintaining homeostasis. The protection of the microbiota against oxidative stress was also an essential aspect of reducing microbial diversity.

Lactobacillus plantarum 69-2 Combined with Galacto-Oligosaccharides Alleviates d-Galactose-Induced Aging by Regulating the AMPK/SIRT1 Signaling Pathway and Gut Microbiota in Mice

Probiotics and prebiotics for preventing and alleviating the degenerative changes associated with aging have received extensive attention. In the present work, Lactobacillus plantarum (L. plantarum) 69-2 with the highest antioxidant capacity combined with galacto-oligosaccharide (GOS) was used in aging model mice to evaluate the effect on aging and the regulation of gut microbiota. The combination of L. plantarum 69-2 and GOS supplementation could significantly (P < 0.05) improve liver function, antioxidant capacity, and inflammation accompanied by regulating the gut microbiota, increasing the short chain fatty acid (SCFA) levels, and activating the hepatic AMPK/SIRT1 regulatory pathway. The results showed that L. plantarum 69-2 and GOS could activate the hepatic AMPK/SIRT1 signaling pathway by regulating the gut microbiota and metabolites through the liver-gut axis to restore hepatic antioxidant activity to alleviate aging. The study provided a new insight for targeting the gut microbiota to relieve aging through the gut-liver axis.