Antioxidative effects in vivo and colonization of Lactobacillus plantarum MA2 in the murine intestinal tract

Kefir mitigates renal damage caused by zearalenone in female wistar rats by reducing oxidative stress

The estrogen-like mycotoxin zearalenone (ZEA) was popularly occurred in several food and feeds, posing threats to human and animal health. ZEA induced renal toxicity and caused oxidative stress. In the current study, the protecting effect of kefir administration against ZEA-induced renal damage in rats was explored. Rats were divided into 4 groups, each consisting of 5 animals. For the initial 7 days, they were orally administered sterile milk (200 μL/day). Subsequently, during the second week, the groups were exposed to kefir (200 μL/day), ZEA (40 mg/kg b.w./day) and a combination of kefir and ZEA. The biochemical parameters, kidney histological changes and ZEA residue were assessed. Kefir supplementation enhanced the antioxidant enzymes in the kidney, such as superoxide dismutase, catalase and glutathione peroxidase activities, which increased by 1.2, 4 and 20 folds, respectively, relative to the ZEA group. Remarkably, the concomitant administration kefir + ZEA suppressed ZEA residues in both serum and kidney. Additionally, serum levels of blood urea nitrogen, uric acid and renal malondialdehyde decreased by 22, 65 and 54%, respectively, in the kefir + ZEA group; while, the creatinine content increased by around 60%. Rats co-treated with kefir showed a normal kidney histological architecture contrary to tissues alterations mediated in the ZEA group. These results suggest that kefir may showed a protective effect on the kidneys, mitigating ZEA-induced acute toxicity in rats.

Acid-tolerant Lactiplantibacillus plantarum ZDY2013 shows a colonization niche preference and interacts with enterotoxigenic Bacillus cereus in specific-pathogen-free mice

Probiotics have long been utilized as functional food and modulate gut microbial homeostasis, but their colonization niche is mostly unclear and transient, which restrains the development of microbiome-targeted strategies. Lactiplantibacillus (L.) plantarum ZDY2013 is an allochthonous species of the human gastrointestinal tract with acid-tolerant properties. It serves as an antagonistic agent against the food-borne pathogen Bacillus (B.) cereus and a potent regulator of the gut microbiota. However, there is a knowledge gap regarding the colonization dynamics of L. plantarum ZDY2013 in the host intestine and the colonization niche of its interaction with pathogens. Here, we designed a pair of specific primers targeting L. plantarum ZDY2013 based on its whole genome sequence. We evaluated their accuracy and sensitivity with other host-derived strains and confirmed their availability with artificially spiked fecal samples from different mouse models. Additionally, the content of L. plantarum ZDY2013 was quantified by qPCR in fecal samples from BALB/c mice, followed by the analysis of its colonization niche preference. Moreover, the interactions between L. plantarum ZDY2013 and enterotoxigenic B. cereus HN001 were also elucidated. The results revealed that the newly designed primers could identify L. plantarum ZDY2013 with high specificity and were resistant to the influence of the complex fecal matrix and gut microbes from different hosts. Interestingly, the content of mixed L. plantarum ZDY2013 and B. cereus HN001 when orally administered remained higher when compared with the single strain group in BALB/c mice upon discontinuation of intragastric administration. In addition, L. plantarum ZDY2013 was mainly enriched in the large intestine during the ingestion period and maintained the highest content in the stomach after discontinuing supplementation on day 7. Moreover, L. plantarum ZDY2013 colonization neither damaged the intestine nor ameliorated the damage triggered by B. cereus in BALB/c mice. Overall, our study constructed two efficient specific primers targeting L. plantarum ZDY2013 and provided the potential to explore the underlying mechanism of competition between L. plantarum ZDY2013 and pathogens in host species.

A tetrapeptide from maize combined with probiotics exerted strong anti-inflammatory effects and modulated gut microbiota in DSS-induced colitis mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by recurrent gastrointestinal inflammation caused by abnormal immune response, and patients usually have intestinal flora imbalance. At present, the pathogenesis of UC is not well understood, and it appears that there is chronic activation of the immune and inflammatory cascade in genetically susceptible individuals. Some food supplements such as specific peptides and probiotics have been investigated and shown the potential for the treatment of UC. The purpose of this study is to investigate the therapeutic effect and potential mechanism of tetrapeptide from maize (TPM) and probiotic treatment on dextran sulfate sodium (DSS)-induced UC in C57BL/6J mice. Our results indicated that the therapeutic effects of TPM and probiotics are positively associated with a reduction in pro-inflammatory cytokine levels and restoration of the gut microbiota. Treatment with TPM or probiotics effectively alleviated the adverse effects of UC, including weight loss, shortened colon length, and colon and kidney tissue damage in mice. Additionally, both TPM and probiotics significantly reduced pro-inflammatory cytokine levels and oxidative stress in UC mice, and the effect was more pronounced when both were used together. Moreover, co-treatment with TPM and probiotics increased the diversity of gut microbes in UC mice, reduced the ratio of Firmicutes to Bacteroidetes (F/B) and increased the abundance of bacterial species, including Muribaculaceae, Alistipes, Ligilactobacillus and Lactobacillus, and has been shown to be beneficial for a variety of pathological conditions.

Probiotic assessment and antioxidant characterization of Lactobacillus plantarum GXL94 isolated from fermented chili

Oxidative stress is caused by an imbalance between prooxidants and antioxidants, which is the cause of various chronic human diseases. Lactic acid bacteria (LAB) have been considered as an effective antioxidant to alleviate oxidative stress in the host. To obtain bacterium resources with good antioxidant properties, in the present study, 113 LAB strains were isolated from 24 spontaneously fermented chili samples and screened by tolerance to hydrogen peroxide (H2O2). Among them, Lactobacillus plantarum GXL94 showed the best antioxidant characteristics and the in vitro antioxidant activities of this strain was evaluated extensively. The results showed that L. plantarum GXL94 can tolerate hydrogen peroxide up to 22 mM, and it could normally grow in MRS with 5 mM H2O2. Its fermentate (fermented supernatant, intact cell and cell-free extract) also had strong reducing capacities and various free radical scavenging capacities. Meanwhile, eight antioxidant-related genes were found to up-regulate with varying degrees under H2O2 challenge. Furthermore, we evaluated the probiotic properties by using in vitro assessment. It was showed that GXL94 could maintain a high survival rate at pH 2.5% or 2% bile salt or 8.0% NaCl, live through simulated gastrointestinal tract (GIT) to colonizing the GIT of host, and also show higher abilities of auto-aggregation and hydrophobicity. Additionally, the usual antibiotic susceptible profile and non-hemolytic activity indicated the safety of the strain. In conclusion, this study demonstrated that L. plantarum GXL94 could be a potential probiotic candidate for producing functional foods with antioxidant properties.

Modulation of the gut microbiota and glycometabolism by a probiotic to alleviate amyloid accumulation and cognitive impairments in AD rats

SCOPE

Regulating the gut microecology by probiotics is an efficient strategy to rational prevention and treatment of Alzheimer's disease (AD). However, there is currently a lack of well-known probiotic species in the protection against AD, and the involved mechanism has not been clearly interpreted.

METHODS AND RESULTS

Herein, Lactobacillus plantarum MA2 (MA2), a functional probiotic isolated from traditional Chinese Tibetan kefir grains, was demonstrated to improve the cognitive deficits and anxiety-like behaviors in the D-galactose/AlCl₃ induced AD rats, and attenuate the neuronal degeneration and Aβ accumulation in the brain. Moreover, we found MA2 could alleviate the intestinal mucosal impairments, and impede the activation of microglia and neuroinflammation through TLR4/MYD88/NLRP3 signaling pathway. 16S rRNA sequencing and metabolomic analysis indicated that MA2 reshaped the gut microbiota structure and composition, and remarkably modulated the glycometabolism. In that case, the EPS (exopolysaccharides) that derived from MA2 was furtherly proved with inhibitory effects on the Aβ42 aggregation and amyloid-induced cytotoxicity.

CONCLUSION

MA2 or MA2 EPS may be used as functional food and nutritional supplement for regulating the gut microbiota and metabolism disorders in AD. This study is of great significance to develop new intervention and therapeutic strategy on AD using probiotics and their metabolites. This article is protected by copyright. All rights reserved.

Lactobacillus kefiranofaciens ZW18 from Kefir enhances the anti-tumor effect of anti-programmed cell death 1 (PD-1) immunotherapy by modulating gut microbiota

The research of probiotics assisting PD-1 inhibitors in anti-tumor has attracted widespread attention. Therefore, it is significative to find new probiotic strains with PD-1 inhibitors promoting effect. This study aims...

Lactobacillus plantarum MA2 Ameliorates Methionine and Choline-Deficient Diet Induced Non-Alcoholic Fatty Liver Disease in Rats by Improving the Intestinal Microecology and Mucosal Barrier

Non-alcoholic fatty liver disease (NAFLD) has become a highly concerned health issue in modern society. Due to the attentions of probiotics in the prevention of NAFLD, it is necessary to further clarify their roles. In this study, the methionine and choline-deficient (MCD) diet induced NAFLD rats model were constructed and treated with strain L. plantarum MA2 by intragastric administration once a day at a dose of 1 × 10⁸ cfu/g.bw. After 56 days of the therapeutic intervention, the lipid metabolism and the liver pathological damage of the NAFLD rats were significantly improved. The content of total cholesterol (TC) and total triglyceride (TG) in serum were significantly lower than that in the NAFLD group (p < 0.05). Meanwhile, the intestinal mucosal barrier and the structure of intestinal microbiota were also improved. The villi length and the expression of claudin-1 was significantly higher than that in the NAFLD group (p < 0.05). Then, by detecting the content of LPS in the serum and the LPS-TLR4 pathway in the liver, we can conclude that Lactobacillus plantarum MA2 could reduce the LPS by regulating the gut microecology, thereby inhibit the activation of LPS-TLR4 and it downstream inflammatory signaling pathways. Therefore, our studies on rats showed that L. plantarum MA2 has the potential application in the alleviation of NAFLD. Moreover, based on the application of the strain in food industry, this study is of great significance to the development of new therapeutic strategy for NAFLD.

Effects of Bacillus amyloliquefaciens Instead of Antibiotics on Growth Performance, Intestinal Health, and Intestinal Microbiota of Broilers

The aim of this study was to evaluate the dietary effects of Bacillus amyloliquefaciens SC06 (SC06) instead of antibiotics on the growth performance, intestinal health, and intestinal microbiota of broilers. A total of 360 30-day-old Lingnan yellow broilers were randomly allocated into two groups with six replicates per group (30 birds per replicate). The broilers were fed either a non-supplemented diet or a diet supplemented with 10⁸ colony-forming units lyophilized SC06 per kilogram feed for 30 days. Results showed that SC06 supplementation had no effect on the growth performance compared with that of the control group. SC06 treatment significantly (P <0.05) increased the total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD) activity in the liver, and the activities of trypsin, α-amylase (AMS), and Na⁺K⁺-ATPase in the ileum, whereas it decreased (P < 0.05) lipase, gamma glutamyl transpeptidase (γ-GT), and maltase activities in the ileum. Meanwhile, SC06 treatment also improved the immune function indicated by the significantly (P < 0.05) increased anti-inflammatory cytokine [interleukin (IL)-10] level and the decreased (P < 0.05) pro-inflammatory cytokine [IL-6 and tumor necrosis factor (TNF)-α] levels in the ileum. Furthermore, we also found that SC06 enhanced the intestinal epithelial intercellular integrity (tight junction and adhesion belt) in the ileum. Microbial analysis showed that SC06 mainly increased the alpha diversity indices in the jejunum, ileum, and cecum. SC06 treatment also significantly (P < 0.05) increased the abundances of Bacteroidetes, Bacteroidales, Bacteroides, Fusobacteria, Clostridiaceae, and Veillonellaceae in the cecum and simultaneously decreased the abundances of Planococcaceae in the duodenum, Microbacteriaceae in the jejunum, and Lachnospiraceae, [Ruminococcus] and Ruminococcus in cecum. In conclusion, these results suggested that B. amyloliquefaciens instead of antibiotics showed a potential beneficial effect on the intestinal health of broilers.

Mining genome traits that determine the different gut colonization potential of Lactobacillus and Bifidobacterium species

Although the beneficial effects of probiotics are likely to be associated with their ability to colonize the gut, little is known about the characteristics of good colonizers. In a systematic analysis of the comparative genomics, we tried to elucidate the genomic contents that account for the distinct host adaptability patterns of Lactobacillus and Bifidobacterium species. The Bifidobacterium species, with species-level phylogenetic structures affected by recombination among strains, broad mucin-foraging activity, and dietary-fibre-degrading ability, represented niche conservatism and tended to be host-adapted. The Lactobacillus species stretched across three lifestyles, namely free-living, nomadic and host-adapted, as characterized by the variations of bacterial occurrence time, guanine-cytosine (GC) content and genome size, evolution event frequency, and the presence of human-adapted bacterial genes. The numbers and activity of host-adapted factors, such as bile salt hydrolase and intestinal tissue-anchored elements, were distinctly distributed among the three lifestyles. The strains of the three lifestyles could be separated with such a collection of colonization-related genomic content (genes, genome size and GC content). Thus, our work provided valuable information for rational selection and gut engraftment prediction of probiotics. Here, we have found many interesting predictive results for bacterial gut fitness, which will be validated in vitro and in vivo.

Gut Colonization Mechanisms of Lactobacillus and Bifidobacterium: An Argument for Personalized Designs

Lactobacillus and Bifidobacterium spp. are best understood for their applications as probiotics, which are often transient, but as commensals it is probable that stable colonization in the gut is important for their beneficial roles. Recent research suggests that the establishment and persistence of strains of Lactobacillus and Bifidobacterium in the gut are species- and strain-specific and affected by natural history, genomic adaptability, and metabolic interactions of the bacteria and the microbiome and immune aspects of the host but also regulated by diet. This provides new perspectives on the underlying molecular mechanisms. With an emphasis on host–microbe interaction, this review outlines how the characteristics of individual Lactobacillus and Bifidobacterium bacteria, the host genotype and microbiome structure,diet, and host–microbe coadaptation during bacterial gut transition determine and influence the colonization process. The diet-tuned and personally tailored colonization can be achieved via a machine learning prediction model proposed here.

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.

Pediococcus pentosaceus ZJUAF-4 relieves oxidative stress and restores the gut microbiota in diquat-induced intestinal injury

Lactic acid bacteria (LAB) play a key role in promoting health and preventing diseases because of their beneficial effects, such as antimicrobial activities, modulating immune responses, maintaining the gut epithelial barrier and antioxidant capacity. However, the mechanisms with which LAB relieve oxidative stress and intestinal injury induced by diquat in vivo are poorly understood. In the present study, Pediococcus pentosaceus ZJUAF-4 (LAB, ZJUAF-4), a selected probiotics strain with strong antioxidant capacities, was appointed to evaluate the efficiency against oxidative stress in diquat-induced intestinal injury of mice. Alanine transaminase (ALT) and aspartate aminotransferase (AST) were analyzed to estimate the liver injury. The intestinal permeability was evaluated by 4 kDa fluorescein isothiocyanate (FITC)-dextran (FD4), D-lactate (DLA), and diamine oxidase (DAO) levels. Jejunum reactive oxygen species (ROS) production was examined by dihydroethidium (DHE) staining. Western blotting was used to detect the expression of nuclear factor (erythroid-derived-2)-like 2 (Nrf2) and its downstream genes in jejunum. The gut microbiota was analyzed by high-throughput sequencing method based on the 16S rRNA genes. The results showed that ZJUAF-4 pretreatment was found to protect the intestinal barrier function and maintain intestinal redox homeostasis under diquat stimulation. Moreover, oral administration of ZJUAF-4 increased the expression of Nrf2 and its downstream genes. High-throughput sequencing analysis indicated that ZJUAF-4 contributed to restoring the gut microbiota influenced by diquat. Our results suggested that ZJUAF-4 protected the intestinal barrier from oxidative stress-induced damage by modulating the Nrf2 pathway and gut microbiota, indicating that ZJUAF-4 may have potential applications in preventing and treating oxidative stress-related intestinal diseases. KEY POINTS: • ZJUAF-4 exerted protective effects against diquat-induced intestinal injury. • Activation of Nrf2 and its downstream targets towards oxidative stress. • ZJUAF-4 administration restoring gut microbiota.

Lactobacillus plantarum Y44 alleviates oxidative stress by regulating gut microbiota and colonic barrier function in Balb/C mice with subcutaneous d-galactose injection

Probiotics have been proved to ameliorate the symptoms of the host induced by oxidative stress. In this study, the protective effects of Lactobacillus plantarum Y44 on Balb/C mice injured by d-galactose (d-gal)-injection were examined. Six weeks of continuous subcutaneous d-gal injection caused liver and colon injury of the Balb/C mice. L. plantarum Y44 administration significantly reversed the injury by modulating hepatic protein expressions related to the Nrf-2/Keap-1 pathway, and enhancing expressions of colonic tight junction proteins. L. plantarum Y44 administration restored the d-gal injection-induced gut microbiota imbalance by manipulating the ratio of Firmicutes/Bacteroidetes (F/B) and Proteobacteria relative abundance at the phylum level, and manipulating relative abundances of Lactobacillaceae, Muribaculaceae, Ruminococcaceae, Desulfovibrionaceae, and Prevotellaceae at the family level. Moreover, the d-gal injection-induced glycerophospholipid metabolism disorder was ameliorated, evidenced by the decline of phosphatidyl ethanolamine (PE), phosphatidylcholine (PC), phosphatidyl serine (PS), and lysophosphatidyl choline (LysoPC) levels in the serum of the mice after the L. plantarum Y44 administration. Spearman correlation analysis revealed a significant correlation between changes in gut microbiota composition, glycerophospholipid levels, and oxidative stress-related indicators. In summary, L. plantarum Y44 administration ameliorated d-gal injection-induced oxidative stress in Balb/C mice by manipulating gut microbiota and intestinal barrier function, and further influenced the glycerophospholipid metabolism and hepatic Nrf-2/Keap-1 pathway-related protein expressions.

Lactobacillus fermentum JX306 Restrain D-galactose-induced Oxidative Stress of Mice through its Antioxidant Activity

Oxidative stress-induced series of related degenerative diseases have received widespread attention. To screen new lactic acid bacteria (LAB) strains to resist oxidative stress, traditional Chinese fermented vegetables were used as a resource library to screen of LAB. The Lactobacillus fermentum JX306 strain, which showed high scavenging activity of DPPH free radical and hydrogen radical, and a strong lipid peroxidation inhibition rate in vitro was selected. L. fermentum JX306 was also examined for its antioxidant capacity in D-galactose-induced aging mice. The results showed that L. fermentum JX306 could significantly decrease malondialdehyde (MDA) levels and improve the activity of glutathione peroxidase (GSH-Px), and total antioxygenic capacity (TOC) in the serum, kidney, and liver. Meanwhile, the strain could remarkably upregulate the transcriptional level of the antioxidant-related enzyme genes, such as peroxiredoxin1 (Prdx1), glutathione reductase (Gsr), glutathione peroxidase (Gpx1), and thioredoxin reductase (TR3) encoding genes in the liver. Besides, histopathological observation proves that this probiotic strain could effectively inhibit oxidative damage to the liver and kidney in aging mice. Therefore, this unique antioxidant strain may have a high application value in the functional food industry and medicine industry.

Lyophilized Probiotic Lactic Acid Bacteria Viability in Potato Chips and Its Impact on Oil Oxidation

To produce a new probiotic-containing food product, potato chips, as the most preferred fast food, were chosen. Preferably, it should be preserved for a long period without oxidation. The presented study aimed to compare potato chips containing two lyophilized probiotic lactic acid bacteria (Bifidobacterium longum ATCC 15708 and Lactobacillus helveticus LH-B02) in order to retard lipid oxidation. Lyophilization of probiotics was carried out into two cryoprotective media-skim milk (SM) and gelatin/glycerol (GG) as lactose-free medium. Results revealed that GG and SM media were the most suitable for lyophilization of B. longum and L. helveticus, respectively. . The lyophilized live cells were incorporated in potato chips, packed and their effect on oil oxidation was assessed. . Results showed that the lyophilized B. longum in SM remained alive at 6.5 log CFU/g for 4 months at 30 °C. Interestingly, potato chip bags containing B. longum lyophilized in SM medium exhibited a decrease in peroxide value (PV) and acid value (AV) of the extracted oil by 40.13% and 25%, respectively, compared to the control bags. The created probiotic potato chips containing B. longum fulfill the criteria of the probiotic product besides the prime quality and sensory attributes.

Isolation of lactic acid bacteria capable of reducing environmental alkyl and fatty acid hydroperoxides, and the effect of their oral administration on oxidative-stressed nematodes and rats

Reinforcement of the hydroperoxide-eliminating activity in the small and large intestines should prevent associated diseases. We previously isolated a lactic acid bacterium, Pediococcus pentosaceus Be1 that facilitates a 2-electron reduction of hydrogen peroxide to water. In this study, we successfully isolated an alternative lactic acid bacterium, Lactobacillus plantarum P1-2, that can efficiently reduce environmental alkyl hydroperoxides and fatty acid hydroperoxides to their corresponding hydroxyl derivatives through a 2-electron reduction. Each strain exhibited a wide concentration range with regard to the environmental reducing activity for each hydroperoxide. Given this, the two lactic acid bacteria were orally administered to an oxygen-sensitive short-lived nematode mutant, and this resulted in a significant expansion of its lifespan. This observation suggests that P. pentosaceus Be1 and L. plantarum P1-2 inhibit internal oxidative stress. To determine the specific organs involved in this response, we performed a similar experiment in rats, involving induced lipid peroxidation by iron-overloading. We observed that only L. plantarum P1-2 inhibited colonic mucosa lipid peroxidation in rats with induced oxidative stress.

Analysis of Health Benefits Conferred by Lactobacillus Species from Kefir

Lactobacilli are among the most common microorganisms found in kefir; a traditional fermented milk beverage produced locally in many locations around the world. Kefir has been associated with a wide range of purported health benefits; such as antimicrobial activity; cholesterol metabolism; immunomodulation; anti-oxidative effects; anti-diabetic effects; anti-allergenic effects; and tumor suppression. This review critically examines and assesses these claimed benefits and mechanisms with regard to particular Lactobacillus species and/or strains that have been derived from kefir; as well as detailing further potential avenues for experimentation.

In vitro selection and in vivo confirmation of the antioxidant ability of Lactobacillus brevis MG000874

AIMS

This study aimed at isolating a probiotic strain from a collection of lactic acid bacteria (LAB) with the high antioxidant property and confirms its potential in d-gal-induced oxidative stress (OS) murine model.

METHODS AND RESULTS

The in vitro antioxidant ability of 16 LAB strains was determined in the cell-free supernatant of 3- to 5-day-old culture, intact cells and cell lysates using three different methods for determining the reactive oxygen species scavenging activity and inhibition of lipid peroxidation. The strain, An28, presented the best antioxidant activity and was identified as Lactobacillus brevis MG000874 on the basis of 16 sRNA gene sequencing. The antioxidant potential of L. brevis MG000874 was confirmed in an OS murine model. Albino mice were exposed to d-galactose at a dose of 150 mg kg^-1 BW and fed with L. brevis MG000874 (0·2 ml of 10¹⁰ CFU per ml cell suspension per animal per day). Antioxidant enzymes were quantified spectrophotometrically in the liver, kidney and serum. Subcutaneous administration of d-gal resulted in decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) and increase in glutathione-S-transferase (GST) levels in animals. The L. brevis MG000874-treated animals displayed improvement in SOD, CAT and GST in all tissues and GSH in the liver and serum. The safety assessment of L. brevis MG000874 was performed by comparing liver and renal function tests. None of the selected indicators was significantly different from the negative control group.

CONCLUSIONS

The antioxidant potential of 16 strains was noticed to be strain specific and in vivo performance of L. brevis MG000874 was found satisfactory in a d-gal murine model.

SIGNIFICANCE AND IMPACT OF THE STUDY

Lactobacillus brevis MG000874 was identified for its admirable antioxidant property. This strain or/and its metabolites could be further investigated for possible applications in humans and veterinary fields.

Probiotic Properties and Cellular Antioxidant Activity of Lactobacillus plantarum MA2 Isolated from Tibetan Kefir Grains

Lactobacillus plantarum MA2 was isolated from traditional Chinese Tibetan kefir grains. Its antioxidant properties had been demonstrated in vitro and in vivo previously. In the present study, the probiotic characteristics of this strain were further evaluated by investigating its acid and bile salt tolerances, cell surface hydrophobicity, and autoaggregation, respectively. In addition, the cellular antioxidant activity (CAA) assay was applied to test the antioxidant capacity of the isolate in different growth phases. Same method was also used to evaluate the antioxidant capacity of its fermentation supernatant, cell-free extract, and intact cell quantitatively. The results of probiotic characteristic tests showed that MA2 could survive at pH 2.5 and 0.3% bile salt. Meanwhile, the measurements of cell surface hydrophobicity and autoaggregation were 45.29 ± 2.15 and 6.30 ± 0.34%, respectively. The results of cellular antioxidant activity tests indicated that MA2 had high antioxidant potential. The CAA value of logarithmic phase cell-free extract of MA2 (39,450.00 ± 424.05 μmol quercetin equivalents/100 g sample) was significantly higher than that in stationary phase cell-free extract (3395.98 ± 126.06 μmol quercetin equivalents/100 g sample) and that of fermentation supernatant in logarithmic phase (2174.41 ± 224.47 μmol quercetin equivalents/100 g sample) (p < 0.05). The CAA method was successively applied to evaluate the antioxidant capacity of MA2 in this study, which suggests that it could be used as a useful method for lactic acid bacteria antioxidant potential evaluation.

Improving effect of a probiotic mixture on memory and learning abilities in d-galactose-treated aging mice

The aim of this study was to evaluate the antiaging effect of a probiotic mixture using an in vivo mouse model in which aging was induced with d-galactose. Results of the Morris water maze test indicated that long-term administration of the probiotic mixture improved memory and learning abilities and ameliorated the apoptosis pattern in the hippocampus of aging mice treated with d-galactose. An antioxidation experiment indicated that administration of the probiotic mixture could restore activities of the antioxidant enzymes superoxide dismutase and catalase and inhibit the production of malondialdehyde. The antioxidant-related proteins nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were upregulated in liver after treatment of d-galactose-treated aging mice with probiotics. Finally, the probiotic treatment did affect the production of short-chain fatty acids in d-galactose-treated aging mice. Our results highlighted a possible antioxidative effect triggered by short-chain fatty acids that contributed to improving the memory and learning abilities following treatment with the probiotic mixture and suggested that probiotics could serve as a therapy to modulate physiological function.

Lactic Acid Bacteria With Antioxidant Activities Alleviating Oxidized Oil Induced Hepatic Injury in Mice

In order to screening new Lactic acid bacteria (LAB) strains to alleviating liver injury induced by oxidized oil, we isolated and screened LAB from Chinese fermented foods. Lactobacillus plantarum AR113, Pediococcus pentosaceus AR243, and Lactobacillus plantarum AR501 showed higher scavenging activity of α, α-Diphenyl-β-Picrylhydrazyl (DPPH) free radical and hydrogen radical, stronger inhibition of lipid peroxidation, and better protective effect on yeast cells in vitro. In vivo, oral administration of L. plantarum AR501 improved the antioxidant status of injury mice induced by oxidized oil including decreasing lipid peroxidation, recovering activities of antioxidant enzymes. Meanwhile, the gene expression of Nuclear factor erythroid 2-related factor 2 (Nrf2) of L. plantarum AR501 group was markedly elevated, and several antioxidant genes such as glutathione S-transferase (GSTO1), heme oxygenase-1 (HO-1), Glutamate cysteine ligase (GCL), and NAD(P)H:quinone oxidoreductase-l (NQO1) were subsequently up regulated in mice liver. Therefore, L. plantarum AR501 could be considered as potential candidates for production of functional foods that can alleviate the oxidative damage induced by oxidized oil.

Lactobacillus plantarum CCFM10 alleviating oxidative stress and restoring the gut microbiota in d-galactose-induced aging mice

Oxidative stress and its correlation with degenerative diseases have been attracting wide attention. In the present study, Lactobacillus plantarum (L. plantarum) CCFM10 and RS15-3 were examined for their abilities to resist oxidative stress in d-galactose (d-gal)-exposed mice. Both strains significantly reversed the changes of hepatic total antioxidant capacity, catalase activity and glutathione content induced by d-gal. The antioxidative abilities of CCFM10 were higher than those of RS15-3. Moreover, the composition of the mice microbiota was changed by d-gal injection, which was characterized by the up-regulated ratio of Firmicutes/Bacteroidetes. At the genus level, the relative abundance of Lactobacillus reduced and the proportion of one genus of Clostridiales increased. However, in probiotic groups, the composition of the microbiota was similar to that of the control group at the phylum and the genus levels, suggesting that probiotic administration can restore the microbiota. Our study suggests that the protective effects of L. plantarum strains on the host microbiota could be one of the mechanisms of their resistance to oxidative stress. Besides this, through comparing the antioxidative capacity of two strains, we also found that the antioxidative capacity of L. plantarum might be strain-specific.

Inhibition of oxidative stress in cholinergic projection neurons fully rescues aging-associated olfactory circuit degeneration in Drosophila

Loss of the sense of smell is among the first signs of natural aging and neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Cellular and molecular mechanisms promoting this smell loss are not understood. Here, we show that Drosophila melanogaster also loses olfaction before vision with age. Within the olfactory circuit, cholinergic projection neurons show a reduced odor response accompanied by a defect in axonal integrity and reduction in synaptic marker proteins. Using behavioral functional screening, we pinpoint that expression of the mitochondrial reactive oxygen scavenger SOD2 in cholinergic projection neurons is necessary and sufficient to prevent smell degeneration in aging flies. Together, our data suggest that oxidative stress induced axonal degeneration in a single class of neurons drives the functional decline of an entire neural network and the behavior it controls. Given the important role of the cholinergic system in neurodegeneration, the fly olfactory system could be a useful model for the identification of drug targets.

Lactobacillus helveticus KLDS1.8701 alleviates d-galactose-induced aging by regulating Nrf-2 and gut microbiota in mice

We first revealed a close association between probiotic-manipulated gut microbiota and hepatic Nrf-2 dependent mechanisms to suppress d-galactose-induced aging.

Effects of probiotic Bacillus as a substitute for antibiotics on antioxidant capacity and intestinal autophagy of piglets

The objective of this study was to evaluate effects of probiotic Bacillus amyloliquefaciens (Ba) as a substitute for antibiotics on growth performance, antioxidant ability and intestinal autophagy of piglets. Ninety piglets were divided into three groups: G1 (containing 150 mg/Kg aureomycin in the diet); G2 (containing 75 mg/Kg aureomycin and 1 × 10⁸ cfu/Kg Ba in the diet); G3 (containing 2 × 10⁸ cfu/Kg Ba in the diet without any antibiotics). Each treatment had three replications of ten pigs per pen. Results showed that Ba replacement significantly increased the daily weight gain of piglets. Moreover, improved antioxidant status in serum and jejunum was noted in Ba-fed groups as compared with aureomycin group. Increased gene expression of antioxidant enzymes and elevated nuclear factor erythroid 2 related factor 2 (Nrf2) in jejunum was also observed in Ba-fed groups. Besides, Ba replacement significantly decreased jejunal c-Jun N-terminal kinase (JNK) phosphorylation compared with antibiotic group. Western blotting results also revealed that replacing all antibiotics with Ba initiated autophagy in the jejunum as evidenced by increased microtubule-associated protein 1 light chain 3 II (LC3-II) abundance. Taken together, these results indicate that replacing aureomycin with Ba can improve growth performance and antioxidant status of piglets via increasing antioxidant capacity and intestinal autophagy, suggesting a good potential for Ba as an alternative to antibiotics in feed.