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.

Wine Barrel Biofilm as a Source of Yeasts with Non-Conventional Properties.

This study investigated the main microbial groups characterizing the interior surface of oak barrels from different years (1890, 1895, 1920, 1975, 2008) used in the production of vino cotto. The yeasts were characterized for the following properties: γ-aminobutyric acid (GABA) production, antioxidant activity, air-liquid interfacial biofilm formation, and anthocyanin adsorption capacity. Community-level physiological profile analysis revealed that the microbial communities inside the barrels used the tested carbon sources in different manners. The following yeast species were identified: Millerozyma farinosa, Zygosaccharomyces bisporus, Wickerhamiella versatilis, Zygosaccharomyces bailii, Starmerella lactis-condensi, and Zygosaccharomyces rouxii. All the strains were able to produce GABA, and S. lactis-condensi, Z. bisporus and Z. rouxii were the highest producers (more than 600 mg/L). The Z. rouxii and Z. bailii strains showed the highest antioxidant activity. Only seven strains out of ten M. farinosa formed air-liquid interfacial biofilm. None of the M. farinosa strains adsorbed anthocyanins on their cell wall. The other strains adsorbed anthocyanins in a strain-dependent way, and the highest adsorption was observed for the W. versatilis strains. The yeasts isolated in this study could be used to increase the functional properties and the quality of fermented foods and beverages.

Edible insects and legumes exert an antioxidant effect on human colon mucosal cells stressed with 2,2'-azobis (2-amidinopropane)-dihydrochloride.

Introduction: Edible insects have been recognized as a more sustainable source of nutrients and bio-active compounds than animal-based products, in line with classical vegetable sources such as legumes. In this study, we assessed the antioxidant properties of four edible insects (silkworms, grasshoppers, mealworms and giant worms) and four legume seeds (lentils, chickpeas, Roveja peas and grass peas). Methods: After the aqueous extraction or in vitro simulated digestion process, selected products were assessed for: (i) in vitro antioxidant capacity through Ferric Reducing Antioxidant Power (FRAP) assay; (ii) the ability to reduce free radicals production induced by a pro-oxidant agent in cells of human colonic mucosa. Results: All the aqueous extracts and digesta of edible insects displayed significantly higher in vitro antioxidant activity than legumes. Moreover, edible insects at all tested concentrations were able to exert an antioxidant effect in the cellular model, while legumes were effective mainly at high concentrations. Discussion: Despite human trials are need to confirm and define these results in a physiological situation, here we suggest a role for edible insects in oxidative stress prevention. Since oxidative stress is strongly correlated with several intestinal pathologies, the results obtained could be interesting for the prevention and relief of the negative symptoms, offering new advantages to their already known ecological and nutritional properties.

High pressure homogenization to boost the technological functionality of native pea proteins.

Pea proteins are being increasingly used for the formulation of plant-based products, but their globular structure and the presence of aggregates can affect their technological properties. In this study, the effect of high pressure homogenization (HPH) at different intensities (60 and 100 MPa) was investigated as a pre-treatment to modulate the techno-functional properties of a pea protein isolate (IP) extracted through an alkaline extraction/isoelectric precipitation process. SDS-PAGE, circular dichroism, thermal properties, total free sulfhydryl groups, antioxidant capacity and reducing properties were evaluated along with technological indices as solubility, WHC and OHC, interfacial tension and emulsifying capacity. HPH treatments were able to unfold and modify proteins structure, leading also to a change of the relative abundance of pea protein globulins (SDS-PAGE) and of the vicilin to legumin ratio. Solubility, WHC and OHC were improved, while interfacial tension and emulsifying capacity were weakly affected. However, an enhanced physical stability over time of the emulsions prepared with the 60 MPa-treated protein was found, likely as an effect of the decreased ratio between vicilin and legumin after treatment. Results of this study will contribute to deepen the effect of the HPH technology used as pre-treatment, adding useful results and expanding knowledge about the structure and techno-functional properties of native and modified pea proteins.

A proteomic insight reveals the role of food-associated Lactiplantibacillus plantarum C9O4 in reverting intestinal inflammation.

Nowadays, Western diets and lifestyle lead to an increasing occurrence of chronic gut inflammation that represents an emerging health concern with still a lack of successful therapies. Fermented foods, and their associated lactic acid bacteria, have recently regained popularity for their probiotic potential including the maintenance of gut homeostasis by modulating the immune and inflammatory response. Our study aims to investigate the crosstalk between the food-borne strain Lactiplantibacillus plantarum C9O4 and intestinal epithelial cells in an in vitro inflammation model. Cytokines profile shows the ability of C9O4 to significantly reduce levels of IL-2, IL-5, IL-6, and IFN-γ. Proteomic functional analysis reveals an immunoregulatory role of C9O4, able to revert the detrimental effects of IFN-γ through the JAK/STAT pathway in inflamed intestinal cells. These results suggest a promising therapeutic role of fermented food-associated microbes for the management of gastrointestinal inflammatory diseases. Data are available via ProteomeXchange with identifier PXD042175.

Exposure to Antibiotics and Neurodevelopmental Disorders: Could Probiotics Modulate the Gut-Brain Axis?

In order to develop properly, the brain requires the intricate interconnection of genetic factors and pre-and postnatal environmental events. The gut-brain axis has recently raised considerable interest for its involvement in regulating the development and functioning of the brain. Consequently, alterations in the gut microbiota composition, due to antibiotic administration, could favor the onset of neurodevelopmental disorders. Literature data suggest that the modulation of gut microbiota is often altered in individuals affected by neurodevelopmental disorders. It has been shown in animal studies that metabolites released by an imbalanced gut-brain axis, leads to alterations in brain function and deficits in social behavior. Here, we report the potential effects of antibiotic administration, before and after birth, in relation to the risk of developing neurodevelopmental disorders. We also review the potential role of probiotics in treating gastrointestinal disorders associated with gut dysbiosis after antibiotic administration, and their possible effect in ameliorating neurodevelopmental disorder symptoms.

The antiinflammatory and antifibrotic effect of olive phenols and Lactiplantibacillus plantarum IMC513 in dextran sodium sulfate-induced chronic colitis.

OBJECTIVES: After a chronic intestinal injury, several intestinal cells switch their phenotype to activated myofibroblasts, which in turn release an abnormal amount of extracellular matrix proteins, leading to the onset of the fibrotic process. To date, no resolutive pharmacological treatments are available, and the identification of new therapeutic approaches represents a crucial goal to achieve. The onset, maintenance, and progression of inflammatory bowel disease are related to abnormal intestinal immune responses to environmental factors, including diet and intestinal microflora components. This study aimed to evaluate the potential antiinflammatory and antifibrotic effect of a biologically debittered olive cream and its probiotic oral administration in an experimental model of dextran sodium sulfate (DSS)-induced chronic colitis. METHODS: Chronic colitis was induced in mice by three cycles of oral administration of 2.5% DSS (5 d of DSS followed by 7 d of tap water). Mice were randomly divided into five groups: 10 control mice fed with standard diet (SD), 20 mice receiving SD and DSS (SD+DSS), 20 mice receiving an enriched diet (ED) with olive cream and DSS (ED+DSS), 20 mice receiving SD plus probiotics (PB; Lactiplantibacillus plantarum IMC513) and DSS (SD+PB+DSS), and 20 mice receiving ED plus PB and DSS (ED+ PB+DSS). Clinical features and large bowel macroscopic, histologic, and immunohistochemical findings were evaluated. RESULTS: The simultaneous administration of ED and PB induced a significant reduction in macroscopic and microscopic colitis scores compared with the other DSS-treated groups. In addition, ED and PB led to a significant decrease in the expression of inflammatory cytokines and profibrotic molecules. CONCLUSIONS: The concomitant oral administration of a diet enriched with biologically debittered olive cream and a specific probiotic strain (Lactiplantibacillus plantarum IMC513) can exert synergistic antiinflammatory and antifibrotic action in DSS-induced chronic colitis. Further studies are needed to define the cellular and molecular mechanisms modulated by olive cream compounds and by Lactiplantibacillus plantarum IMC513.

Health-Promoting Role of Lactiplantibacillus plantarum Isolated from Fermented Foods.

Fermentation processes have been used for centuries for food production and preservation. Besides the contribution of fermentation to food quality, recently, scientific interest in the beneficial nature of fermented foods as a reservoir of probiotic candidates is increasing. Fermented food microbes are gaining attention for their health-promoting potential and for being genetically related to human probiotic bacteria. Among them, Lactiplantibacillus (Lpb.) plantarum strains, with a long history in the food industry as starter cultures in the production of a wide variety of fermented foods, are being investigated for their beneficial properties which are similar to those of probiotic strains, and they are also applied in clinical interventions. Food-associated Lpb. plantarum showed a good adaptation and adhesion ability in the gastro-intestinal tract and the potential to affect host health through various beneficial activities, e.g., antimicrobial, antioxidative, antigenotoxic, anti-inflammatory and immunomodulatory, in several in vitro and in vivo studies. This review provides an overview of fermented-associated Lpb. plantarum health benefits with evidence from clinical studies. Probiotic criteria that fermented-associated microbes need to fulfil are also reported.

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.

Genotypic and phenotypic characterization of food-associated Lactobacillus plantarum isolates for potential probiotic activities.

Lactic acid bacterium, Lactobacillus plantarum, has been applied, for centuries, for food and drink fermentations. Given the benefits associated with fermented products, Lb. plantarum strains have captured considerable industrial and scientific interest, so that they are included as fundamental components of functional foods. Indeed, some strains are marketed as probiotics. In the present study, food- and gut-associated Lb. plantarum isolates were genetically characterized by multilocus sequence typing (MLST) and phenotypically characterized for properties that could influence their probiotic potential. MLST and phylogenetic analysis stratified 22 Lb. plantarum isolates into six lineages. The isolates were further phenotypically characterized by an in vitro assay to assess their potential gut community influence via a limited number of assays including acidification activity, strain displacement activity and their intrinsic range of antibiotic resistance. Given growing recognition of the benefits of fermented foods, and the prevalence of Lb. plantarum in these applications, this study highlights analysis of a subset of preliminary important strain-specific features. These features are of interest to all stakeholders, to inform isolate comparison and selection for current functional food associations, and that can serve as a basis for future strain and food-microbe fermentation product development.

Food-borne Lactiplantibacillus plantarum protect normal intestinal cells against inflammation by modulating reactive oxygen species and IL-23/IL-17 axis.

Food-associated Lactiplantibacillus plantarum (Lpb. plantarum) strains, previously classified as Lactobacillus plantarum, are a promising strategy to face intestinal inflammatory diseases. Our study was aimed at clarifying the protective role of food-borne Lpb. plantarum against inflammatory damage by testing the scavenging microbial ability both in selected strains and in co-incubation with normal mucosa intestinal cells (NCM460). Here, we show that Lpb. plantarum endure high levels of induced oxidative stress through partially neutralizing reactive oxygen species (ROS), whereas they elicit their production when co-cultured with NCM460. Moreover, pre-treatment with food-borne Lpb. plantarum significantly reduce pro-inflammatory cytokines IL-17F and IL-23 levels in inflamed NCM460 cells. Our results suggest that food-vehicled Lpb. plantarum strains might reduce inflammatory response in intestinal cells by directly modulating local ROS production and by triggering the IL-23/IL-17 axis with future perspectives on health benefits in the gut derived by the consumption of functional foods enriched with selected strains.

Probiotic antigenotoxic activity as a DNA bioprotective tool: a minireview with focus on endocrine disruptors.

Nowadays, the interest in the role of dietary components able to influence the composition and the activity of the intestinal microbiota and, consequently, to modulate the risk of genotoxicity and colon cancer is increasing in the scientific community. Within this topic, the microbial ability to have a protective role at gastrointestinal level by counteracting the biological activity of genotoxic compounds, and thus preventing the DNA damage, is deemed important in reducing gut pathologies and is considered a new tool for probiotics and functional foods. A variety of genotoxic compounds can be found in the gut and, besides food-related mutagens and other DNA-reacting compounds, there is a group of pollutants commonly used in food packaging and/or in thousands of everyday products called endocrine disruptors (EDs). EDs are exogenous substances that alter the functions of the endocrine system through estrogenic and anti-estrogenic activity, which interfere with normal hormonal function in human and wildlife. Thus, this paper summarizes the main applications of probiotics, mainly lactobacilli, as a bio-protective tool to counteract genotoxic and mutagenic agents, by biologically inhibiting the related DNA damage in the gut and highlights the emerging perspectives to enlarge and further investigate the microbial bio-protective role at intestinal level.

Table Olives More than a Fermented Food.

Table olives are one of the oldest vegetable fermented foods in the Mediterranean area. Beside their economic impact, fermented table olives represent also an important healthy food in the Mediterranean diet, because of their high content of bioactive and health-promoting compounds. However, olive fermentation is still craft-based following traditional processes, which can lead to a not fully predictable final product with the risk of spontaneous alterations. Nowadays, food industries have to face consumer demands for safe and healthy products. This review offers an overview about the main technologies used for olive fermentation and the role of lactic acid bacteria and yeasts characterizing this niche during the fermentation. Particular attention is offered to the selection and use of microorganisms as starter cultures to fasten and improve the safety of table olives. The development and implementation of multifunctional starter cultures in order to obtain heath-oriented table olives is also discussed.

Beneficial bile acid metabolism from Lactobacillus plantarum of food origin.

Bile acid (BA) signatures are altered in many disease states. BA metabolism is an important microbial function to assist gut colonization and persistence, as well as microbial survival during gastro intestinal (GI) transit and it is an important criteria for potential probiotic bacteria. Microbes that express bile salt hydrolase (BSH), gateway BA modifying enzymes, are considered to have an advantage in the gut. This property is reported as selectively limited to gut-associated microbes. Food-associated microbes have the potential to confer health benefits to the human consumer. Here, we report that food associated Lactobacillus plantarum strains are capable of BA metabolism, they can withstand BA associated stress and propagate, a recognised important characteristic for GIT survival. Furthermore, we report that these food associated Lactobacillus plantarum strains have the selective ability to alter BA signatures in favour of receptor activation that would be beneficial to humans. Indeed, all of the strains examined showed a clear preference to alter human glycol-conjugated BAs, although clear strain-dependent modifications were also evident. This study demonstrates that BA metabolism by food-borne non-pathogenic bacteria is beneficial to both microbe and man and it identifies an evolutionary-conserved characteristic, previously considered unique to gut residents, among food-associated non-pathogenic isolates.

Corrigendum: Changes in Polyphenolic Concentrations of Table Olives (cv. Itrana) Produced Under Different Irrigation Regimes During Spontaneous or Inoculated Fermentation.

[This corrects the article DOI: 10.3389/fmicb.2018.01287.].

Adhesion Properties of Food-Associated Lactobacillus plantarum Strains on Human Intestinal Epithelial Cells and Modulation of IL-8 Release.

Food-associated microbes can reach the gut as viable cells and interact with the human host providing potential health benefits. In this study, we evaluated the impact on cell viability and the adhesion ability of 22 Lactobacillus plantarum strains, mainly isolated from fermented foods, on a Normal-derived Colon Mucosa cell line. Furthermore, due to the presence of mucus layer on the gut epithelium, we also investigated whether the mucin could affect the microbial adhesion property. Our results demonstrated that all the strains displayed a strong ability to adhere to host cells, showing a strain-dependent behavior with preference for cell edges, that resulted not to be affected by the presence of mucin. Based on interleukin-8 release of intestinal cells induced by some Lb. plantarum strains, our data suggest a potential cross-talk with the host immune system as unconventional property of these food-associated microbes.

Changes in Polyphenolic Concentrations of Table Olives (cv. Itrana) Produced Under Different Irrigation Regimes During Spontaneous or Inoculated Fermentation.

Irrigation is widely used for the production of table olives because it increases fruit size and yield. However, irrigation also determines less accumulation of total phenols, an increase in water content, a decrease of firmness, lower concentrations of soluble sugars in the mesocarp, thus positively or negatively affecting the fermentation process for the production of table olives. In this study we tested the hypothesis that green fruits of cultivar Itrana obtained by different irrigation regimes had different phenolic concentration that responded differentially to spontaneous or inoculated fermentation. Fruits were harvested from two orchards in the Latina province of Latium, Italy, which had been irrigated with different volumes of water during the growing season to compare the evolution of spontaneous and inoculated fermentation processes. We measured fruit characteristics at harvest, changes in the concentrations of secoiridoids and lignans, and main microbial groups abundance during fermentation. At harvest and during fermentation the concentration of phenolic compounds was higher in fruits sampled from trees that had received less water in the field. Differences were observed between spontaneous and inoculated fermentations, with a prevalence of lactic acid bacteria (LAB) in inoculated samples. In particular, oleuropein concentration completely disappeared only from samples inoculated with the two selected strains used as starters. The inoculum with selected LAB positively influenced the fermentation process of green olives, whereas the irrigation regime previously experienced by trees did not alter fermentation.

Food-Associated Lactobacillus plantarum and Yeasts Inhibit the Genotoxic Effect of 4-Nitroquinoline-1-Oxide.

Lactic acid bacteria and yeasts, representing the prevailing microbiota associated with different foods generally consumed without any cooking, were identified and characterized in vitro for some functional properties, such as acid-bile tolerance and antigenotoxic activity. In particular, 22 Lactobacillus plantarum strains and 14 yeasts were studied. The gastro-intestinal tract tolerance of all the strains was determined by exposing washed cell suspensions at 37°C to a simulated gastric juice (pH 2.0), containing pepsin (0.3% w/v) and to a simulated small intestinal juice (pH 8.0), containing pancreatin (1 mg mL-1) and bile extract (0.5%), thus monitoring changes in total viable count. In general, following a strain-dependent behavior, all the tested strains persisted alive after combined acid-bile challenge. Moreover, many strains showed high in vitro inhibitory activity against a model genotoxin, 4-nitroquinoline-1-oxide (4-NQO), as determined by the short-term method, SOS-Chromotest. Interestingly, the supernatants from bacteria- or yeasts-genotoxin co-incubations exhibited a suppression on SOS-induction produced by 4-NQO on the tester strain Escherichia coli PQ37 (sfiA::lacZ) exceeding, in general, the value of 75%. The results highlight that food associated microorganisms may reach the gut in viable form and prevent genotoxin DNA damage in situ. Our experiments can contribute to elucidate the functional role of food-associated microorganisms general recognized as safe ingested with foods as a part of the diet.

Bacterial Composition, Genotoxicity, and Cytotoxicity of Fecal Samples from Individuals Consuming Omnivorous or Vegetarian Diets.

This study analyzes the composition of viable fecal bacteria and gut toxicology biomarkers of 29 healthy volunteers, who followed omnivorous, lacto-ovo-vegetarian, or vegan diets. In particular, the research was focused on the prevalence of some representative viable bacteria from the four dominant phyla (Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria) commonly present in human feces, in order to evaluate the relationship between microorganisms selected by the habitual dietary patterns and the potential risk due to fecal water (FW) genotoxicity and cytotoxicity, considered as biomarkers for cancer risk and protective food activity. The relative differences of viable bacteria among dietary groups were generally not statistically significant. However, compared to omnivores, lacto-ovo-vegetarians showed low levels of total anaerobes. Otherwise, vegans showed total anaerobes counts similar to those of omnivores, but with lower number of bifidobacteria and the highest levels of bacteria from the Bacteroides-Prevotella genera. FW genotoxicity of lacto-ovo-vegetarians resulted significantly lower either in relation to that of omnivores and vegans. Lacto-ovo-vegetarians also showed the lowest levels of cytotoxicity, while the highest were found for vegans. These results highlighted that lacto-ovo-vegetarian diet was particularly effective in a favorable modulation of microbial activity, thus contributing to a significant reduction of the genotoxic and cytotoxic risk in the gut.