In vitro screening and characterization of lactic acid bacteria from Lithuanian fermented food with potential probiotic properties

The present work aimed to identify probiotic candidates from Lithuanian homemade fermented food samples. A total of 23 lactic acid bacteria were isolated from different fermented food samples. Among these, only 12 showed resistance to low pH, tolerance to pepsin, bile salts, and pancreatin. The 12 strains also exhibited antimicrobial activity against Staphylococcus aureus ATCC 29213, Salmonella Typhimurium ATCC 14028, Streptococcus pyogenes ATCC 12384, Streptococcus pyogenes ATCC 19615, and Klebsiella pneumoniae ATCC 13883. Cell-free supernatants of isolate 3A and 55w showed the strongest antioxidant activity of 26.37 μg/mL and 26.06 μg/mL, respectively. Isolate 11w exhibited the strongest auto-aggregation ability of 79.96% as well as the strongest adhesion to HCT116 colon cells (25.671 ± 0.43%). The selected strains were tested for their synbiotic relation in the presence of a prebiotic. The selected candidates showed high proliferation in the presence of 4% as compared to 2% galactooligosaccharides. Among the strains tested for tryptophan production ability, isolate 11w produced the highest L-tryptophan levels of 16.63 ± 2.25 μm, exhibiting psychobiotic ability in the presence of a prebiotic. The safety of these strains was studied by ascertaining their antibiotic susceptibility, mucin degradation, gelatin hydrolysis, and hemolytic activity. In all, isolates 40C and 11w demonstrated the most desirable probiotic potentials and were identified by 16S RNA and later confirmed by whole genome sequencing as Lacticaseibacillus paracasei 11w, and Lactiplantibacillus plantarum 40C: following with the harboring plasmid investigation. Out of all the 23 selected strains, only Lacticaseibacillus paracasei 11w showed the potential and desirable probiotic properties.

Evaluation of Different Activity of Lactobacillus spp. against Two Proteus mirabilis Isolated Clinical Strains in Different Anatomical Sites In Vitro: An Explorative Study to Improve the Therapeutic Approach

Urinary tract infections (UTIs) and catheter-associated UTIs (CAUTIs) are the principal hospital-acquired infections. Between these, bacterial prostatitis is believed to be the leading cause of recurrent UTIs in men under 50 years of age and is often unresponsive to antibiotic treatment. Proteus mirabilis is more commonly associated with UTIs in these abnormalities, especially in patients undergoing catheterization. Lactobacillus spp. are an important component of the human microbiota and occur in large quantities in foods. Probiotics are proposed as an alternative to antibiotic therapy in the treatment of urinary tract infections. In addition to their ability to produce antimicrobial metabolites, they have immunomodulatory activity and do not cause side effects. For this reason, the combination of probiotic microorganisms and conventional drugs was considered. The aim of this work was to select the most active Lactobacillus strains against two clinical isolates of P. mirabilis on bladder and prostatic epithelium, potentially exploitable to improve the clinical management of UTIs.

Identification of novel lactic acid bacteria with enhanced protective effects against influenza virus

Lactic acid bacteria (LAB) exert health-beneficial effects by regulating innate immunity in the intestinal tract. Due to growing health awareness, the demand for LAB and studies have focused on identifying beneficial LAB strains is increasing, especially those that stimulate innate immunity. In this study, the LAB strain D279 (NITE_BP-03645, Latilactobacillus sakei) was isolated from among 741 LAB strains that were analyzed for their ability to induce interleukin 12 (IL-12) production and was subsequently characterized. D279 induced the highest expression of IL-12 among the screened LABs. Furthermore, D279 significantly activated antiviral genes and preferentially induced interferon (IFN)λ expression in vitro, which plays a critical role in the epithelial tissue, thereby conferring strong anti-influenza potency without inflammation. However, it decreased the IFNα levels. The administration of pasteurized D279 to mice resulted in strong anti-influenza potency, with higher natural killer (NK) cell activity and a lower viral load in the lung than in the control. Importantly, none of the D279-administered mice were sacrificed during the viral infection tests. These results suggest that D279 administration confers beneficial effects by regulating innate immunity and that it may be relevant for commercial use in the future.

The Impacts of Acidophilic Lactic Acid Bacteria on Food and Human Health: A Review of the Current Knowledge

The need to improve the safety/quality of food and the health of the hosts has resulted in increasing worldwide interest in acidophilic lactic acid bacteria (LAB) for the food, livestock as well as health industries. In addition to the use of acidophilic LAB with probiotic potential for food fermentation and preservation, their application in the natural disposal of acidic wastes polluting the environment is also being investigated. Considering this new benefit that has been assigned to probiotic microorganisms in recent years, the acceleration in efforts to identify new, efficient, promising probiotic acidophilic LAB is not surprising. One of these effots is to determine both the beneficial and harmful compounds synthesized by acidophilic LAB. Moreover, microorganisms are of concern due to their possible hemolytic, DNase, gelatinase and mucinolytic activities, and the presence of virulence/antibiotic genes. Hence, it is argued that acidophilic LAB should be evaluated for these parameters before their use in the health/food/livestock industry. However, this issue has not yet been fully discussed in the literature. Thus, this review pays attention to the less-known aspects of acidophilic LAB and the compounds they release, clarifying critical unanswered questions, and discussing their health benefits and safety.

Biomaterials and Encapsulation Techniques for Probiotics: Current Status and Future Prospects in Biomedical Applications

Probiotics have garnered significant attention in recent years due to their potential advantages in diverse biomedical applications, such as acting as antimicrobial agents, aiding in tissue repair, and treating diseases. These live bacteria must exist in appropriate quantities and precise locations to exert beneficial effects. However, their viability and activity can be significantly impacted by the surrounding tissue, posing a challenge to maintain their stability in the target location for an extended duration. To counter this, researchers have formulated various strategies that enhance the activity and stability of probiotics by encapsulating them within biomaterials. This approach enables site-specific release, overcoming technical impediments encountered during the processing and application of probiotics. A range of materials can be utilized for encapsulating probiotics, and several methods can be employed for this encapsulation process. This article reviews the recent advancements in probiotics encapsulated within biomaterials, examining the materials, methods, and effects of encapsulation. It also provides an overview of the hurdles faced by currently available biomaterial-based probiotic capsules and suggests potential future research directions in this field. Despite the progress achieved to date, numerous challenges persist, such as the necessity for developing efficient, reproducible encapsulation methods that maintain the viability and activity of probiotics. Furthermore, there is a need to design more robust and targeted delivery vehicles.

Flavour by design: food-grade lactic acid bacteria improve the volatile aroma spectrum of oat milk, sunflower seed milk, pea milk, and faba milk towards improved flavour and sensory perception

BACKGROUND

The global market of plant-based milk alternatives is continually growing. Flavour and taste have a key impact on consumers' selection of plant-based beverages. Unfortunately, natural plant milks have only limited acceptance. Their typically bean-like and grassy notes are perceived as "off-flavours" by consumers, while preferred fruity, buttery, and cheesy notes are missing. In this regard, fermentation of plant milk by lactic acid bacteria (LAB) appears to be an appealing option to improve aroma and taste.

RESULTS

In this work, we systematically studied LAB fermentation of plant milk. For this purpose, we evaluated 15 food-approved LAB strains to ferment 4 different plant milks: oat milk (representing cereal-based milk), sunflower seed milk (representing seed-based milk), and pea and faba milk (representing legume-based milk). Using GC‒MS analysis, flavour changes during anaerobic fermentations were studied in detail. These revealed species-related and plant milk-related differences and highlighted several well-performing strains delivered a range of beneficial flavour changes. A developed data model estimated the impact of individual flavour compounds using sensory scores and predicted the overall flavour note of fermented and nonfermented samples. Selected sensory perception tests validated the model and allowed us to bridge compositional changes in the flavour profile with consumer response.

CONCLUSION

Specific strain-milk combinations provided quite different flavour notes. This opens further developments towards plant-based products with improved flavour, including cheesy and buttery notes, as well as other innovative products in the future. S. thermophilus emerged as a well-performing strain that delivered preferred buttery notes in all tested plant milks. The GC‒MS-based data model was found to be helpful in predicting sensory perception, and its further refinement and application promise enhanced potential to upgrade fermentation approaches to flavour-by-design strategies.

Probiotic properties and antimicrobial evaluation of silymarin-enriched Lactobacillus bacteria isolated from traditional curd

Nowadays, the increasing use of medicinal plants in the treatment and prevention of diseases has attracted the attention of researchers. The aim of this work was to investigate the probiotic properties and antibacterial and antifungal activity of silymarin-enriched Lactobacillus bacteria against several important pathogenic bacteria and also Aspergillus flavus as one of the harmful molds in the food and health industries. For this purpose, 52 g-positive and catalase-negative bacteria were isolated from 60 traditional curd samples from Ilam province. Five of the 52 bacterial strains had more than 90% viability in high bile salt and acidic conditions and were selected for further investigation. The five strains with positive results showed good hydrophobicity (≥ 50.30%), auto-aggregation (≥ 53.70%), coaggregation (≥ 28.20%), and high cholesterol removal ability (from 09.20 to 67.20%) and therefore can be considered potential probiotics. The tested strains displayed acceptable antibacterial and antifungal activity against all 12 pathogenic bacteria and A. flavus. Also, the results of the simultaneous antifungal activity of probiotic strains and silymarin showed that the combination of silymarin and probiotics has a significantly better (P < 0.05) antifungal effect than the control group or the probiotic groups alone. Interestingly, in addition to the Limosilactobacillus fermentum C3 strain, the Limosilactobacillus fermentum C18 and Lactiplantibacillus pentosus C20 strains also had significant inhibitory effects against A. flavus when used with silymarin extract in methanol. Meanwhile, silymarin extract in DMSO and PEG increased the antagonistic activity of all five potential probiotic strains.

Boosting the Antioxidant Potential of Polymeric Proanthocyanidins in Litchi (Litchi chinensis Sonn.) Pericarp via Biotransformation of Utilizing Lactobacillus Plantarum

In order to enhance the efficient utilization of polymeric proanthocyanidins from litchi pericarp, a process for transforming litchis' polymeric proanthocyanidins (LPPCs) by using Lactobacilli has been established for products with highly antioxidative properties. Lactobacillus plantarum was selected to enhance the transformation effect. The transformation rate of LPPCs reached 78.36%. The content of litchis' oligomeric proanthocyanidins (LOPCs) in the products achieved 302.84 μg grape seed proanthocyanidins (GPS)/mg DW, while that of total phenols was 1077.93 gallic acid equivalents (GAE) μg/mg DW. Seven kinds of substances have been identified in the products by using the HPLC-QTOF-MS/MS method, among which 4-hydroxycinnamic acid, 3,4-dihydroxy-cinnamic acid, and proanthocyanidin A2 were major components. The in vitro antioxidative activity of the products after transformation was significantly (p < 0.05) higher than those of LOPCs and LPPCs. The scavenging activity of the transformed products for DPPH free radicals was 1.71 times that of LOPCs. The rate of inhibiting conjugated diene hydroperoxides (CD-POV) was 2.0 times that of LPPCs. The scavenging activity of the products for ABTS free radicals was 11.5 times that of LPPCs. The ORAC value of the products was 4.13 times that of LPPCs. In general, this study realizes the transformation of polymeric proanthocyanidins into high-activity small-molecule substances.

The Effects of Synbiotics on Dextran-Sodium-Sulfate-Induced Acute Colitis: The Impact of Chitosan Oligosaccharides on Endogenous/Exogenous Lactiplantibacillus plantarum

In this work, Lactiplantibacillus plantarum (L. plantarum) isolated from mice feces (LP-M) and pickles (LP-P) were chosen as the endogenous and exogenous L. plantarum, respectively, which were separately combined with chitosan oligosaccharides (COS) to be synbiotics. The anti-inflammatory activity of LP-M, LP-P, COS, and the synbiotics was explored using dextran-sodium-sulfate (DSS)-induced acute colitis mice, as well as by comparing the synergistic effects of COS with LP-M or LP-P. The results revealed that L. plantarum, COS, and the synbiotics alleviated the symptoms of mice colitis and inhibited the changes in short-chain fatty acids (SCFAs), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-10, and myeloperoxidase (MPO) caused by DSS. In addition, the intervention of L. plantarum, COS, and the synbiotics increased the relative abundance of beneficial bacteria Muribaculaceae and Lactobacillus and suppressed the pathogenic bacteria Turicibacter and Escherichia-Shigella. There was no statistically difference between LP-M and the endogenous synbiotics on intestinal immunity and metabolism. However, the exogenous synbiotics improved SCFAs, inhibited the changes in cytokines and MPO activity, and restored the gut microbiota more effectively than exogenous L. plantarum LP-P. This indicated that the anti-inflammatory activity of exogenous LP-P can be increased by combining it with COS as a synbiotic.

Lactic Acid Bacteria (LAB) and Neuroprotection, What Is New? An Up-To-Date Systematic Review

BACKGROUND

In recent years, the potential role of probiotics has become prominent in the discoveries of neurotherapy against neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Lactic acid bacteria (LAB) exhibit neuroprotective properties and exert their effects via various mechanisms of actions. This review aimed to evaluate the effects of LAB on neuroprotection reported in the literature.

METHODS

A database search on Google Scholar, PubMed, and Science Direct revealed a total of 467 references, of which 25 were included in this review based on inclusion criteria which comprises 7 in vitro, 16 in vivo, and 2 clinical studies.

RESULTS

From the studies, LAB treatment alone or in probiotics formulations demonstrated significant neuroprotective activities. In animals and humans, LAB probiotics supplementation has improved memory and cognitive performance mainly via antioxidant and anti-inflammatory pathways.

CONCLUSIONS

Despite promising findings, due to limited studies available in the literature, further studies still need to be explored regarding synergistic effects, efficacy, and optimum dosage of LAB oral bacteriotherapy as treatment or prevention against neurodegenerative diseases.

Antibiotic resistance profiling and valorization of food waste streams to starter culture biomass and exopolysaccharides through fed-batch fermentations

The present study evaluated antibiotic resistance (ABR) in bacteria isolated from different food wastes viz., meat slaughterhouses, dairy and restaurants. About 120 strains isolated from the food waste were subjected to ABR screening. More than 50% of all the strains were resistant to Vancomycin, Neomycin and Methicilin, which belong to third-generation antibiotics. Two lactic acid bacteria (LAB) free of ABR were chosen to be used as starter cultures in media formulated from food waste. Food waste combination (FWC-4) was found to be on par with the nutrient broth in biomass production. The non-ABR LAB strains showed excellent probiotic properties, and in the fed-batch fermentation process, adding a nitrogen source (soya protein) enhanced the microbial biomass (3.7 g/l). Additionally, exopolysaccharide production was found to be 2.3 g/l. This study highlights the ABR incidence in food waste medium and its economic advantage for starter culture biomass production.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01222-9.

Fermentation Kinetics, Microbiological and Physical Properties of Fermented Soy Beverage with Acai Powder

In this study, the effects of the fermentation kinetics, determination of the number of lactic acid bacteria, texture, water holding capacity, and color of fermented soy beverages with acai powder (3 and 6% w/v) were investigated. The addition of acai powder significantly influenced the fermentation kinetics based on changes in pH, accelerating fermentation in the initial period. The results showed that the acai additive did not affect the enumeration of Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis. The presence of acai inhibited the proliferation of Streptococcus thermophilus compared to the soy beverage without acai powder added. However, the higher the acai additive, the more Streptococcus thermophilus bacteria were detected: 4.39 CFU/g for 6% acai powder sample and 3.40 CFU/g for 3% acai powder sample. The addition of acai to the soy beverage reduced its firmness, consistency, cohesiveness, and viscosity index after fermentation. A slight difference was observed in the lightness and whiteness of fermented soy beverages with 3% and 6% acai powder.

Exploring the Inhibitory Activity of Selected Lactic Acid Bacteria against Bread Rope Spoilage Agents

In this study, a wide pool of lactic acid bacteria strains deposited in two recognized culture collections was tested against ropy bread spoilage bacteria, specifically belonging to Bacillus spp., Paenibacillus spp., and Lysinibacillus spp. High-throughput and ex vivo screening assays were performed to select the best candidates. They were further investigated to detect the production of active antimicrobial metabolites and bacteriocins. Moreover, technological and safety features were assessed to value their suitability as biocontrol agents for the production of clean-label bakery products. The most prominent inhibitory activities were shown by four strains of Lactiplantibacillus plantarum (NFICC19, NFICC 72, NFICC163, and NFICC 293), two strains of Pediococcus pentosaceus (NFICC10 and NFICC341), and Leuconostoc citreum NFICC28. Moreover, the whole genome sequencing of the selected LAB strains and the in silico analysis showed that some of the strains contain operons for bacteriocins; however, no significant evidence was observed phenotypically.

A Comparative Study of Skimmed Milk and Cassava Flour on the Viability of Freeze-Dried Lactic Acid Bacteria as Starter Cultures for Yogurt Fermentation

The purpose of this study was to evaluate the survival rates and fermentation performance of three freeze-dried lactic acid bacterial cultures previously isolated from Ghanaian traditional fermented milk. LAB cultures, i.e., Lactobacillus delbrueckii, Lactococcus lactis and Leuconostoc mesenteroides, were frozen in the chamber of a Telstar (Lyoquest) laboratory freeze dryer for 10 h at -55 °C (as single and combined cultures) using skimmed milk and cassava flour as cryoprotectants held in plastic or glass cryovials. For viability during storage, freeze-dried LAB cultures were stored in a refrigerator (4 °C) and at room temperature (25 °C) for 4 weeks. The survival of freeze-dried cultures was determined by growth kinetics at 600 nm (OD600). The performance of freeze-dried LAB cultures after 4 weeks of storage was determined by their growth, acidification of milk during yogurt fermentation and consumer sensory evaluation of fermented milk using a nine-point hedonic scale. The survival rates for LAB ranged between 60.11% and 95.4% following freeze-drying. For single cultures, the highest survival was recorded for Lactobacillus delbrueckii (L12), whereas for combined cultures, the highest survival was observed for Lactococcus lactis (L3) combined with Lactobacillus delbrueckii (L12). The consumer acceptability results showed that yogurts produced from a combined starter culture of Lactococcus lactis and Lactobacillus delbrueckii or from a single culture of Lactococcus lactis were the most preferred products with Lactococcus lactis and Lactobacillus delbrueckii possessing high survival rates and high consumer acceptability in yogurt production. These findings are crucial and can be adopted for large-scale production and commercialization of yogurt.

In Vitro Evaluation of the Most Active Probiotic Strains Able to Improve the Intestinal Barrier Functions and to Prevent Inflammatory Diseases of the Gastrointestinal System

Background: The integrity of the intestinal barrier is fundamental to gut health and homeostasis; its damage can increase intestinal permeability, with translocation of bacteria and/or endotoxins from gut, and the onset of various intestinal diseases. Lactobacillus spp. is one of the most common probiotics normally found in fermented foods and dairy products and is known for its anti-inflammatory and immunomodulatory properties and for its ability to protect and enhance the intestinal barrier functions. The aim of this work was to evaluate the ability of different strains of Lactobacillus spp. to improve in vitro the integrity of the intestinal barrier, to exert anti-inflammatory and immunomodulatory activity and to prevent Salmonella Typhimurium and enteroinvasive Escherichia coli (EIEC) infections. Methods: We analyzed the cellular expression of tight junctions, antimicrobial peptide HBD-2, pro-inflammatory cytokines and the inhibition of pathogens adhesion and invasion in a model of co-cultured epithelial cells treated with Lactobacillus spp. Results: L. brevis, L. reuteri and L. rhamnosus proved to be more effective in protecting the intestinal epithelium. Conclusions: These in vitro studies can help select strains particularly active in their intended use to obtain consortia formulations that can have as much maximum yield as possible in terms of patient benefit.

Comparison of Activity of Commercial Protective Cultures and Thermophilic Lactic Acid Bacteria against Listeria monocytogenes: A New Perspective to Improve the Safety of Sardinian PDO Cheeses

Listeria monocytogenes contamination that occurs during and post-processing of dairy products is a serious concern for consumers, and bioprotective cultures can be applied to control the growth of the pathogen in sheep milk cheeses. However, to respect specifications provided for protected designation of origin (PDO) cheeses, only autochthonous microorganisms can be used as bioprotective cultures in these products. This in vitro study aimed to evaluate thermophilic lactic acid bacteria (LAB) isolated from sheep milk as bio-preservative agents to control L. monocytogenes growth in PDO cheese. Results were compared with those obtained with a commercial protective culture (cPC) composed of a Lactiplantibacillus plantarum bacteriocin producer designed to inhibit L. monocytogenes growth in cheese. The in vitro antilisterial activities of n.74 autochthonous LAB and a cPC were tested against 51 L. monocytogenes strains using an agar well diffusion assay. In addition, 16S rRNA sequencing of LAB isolates with antilisterial activity was conducted and strains of Lactobacillus helveticus, Lactobacillus delbrueckii subsp. indicus, Lactobacillus delbrueckii subsp. sunkii, Lactobacillus delbrueckii subsp. lactis and Enterococcus faecalis were identified. In this study, 33.6% (74/220) bacterial strains isolated from milk had characteristics compatible with thermophilic LAB, of which 17.6% (13/74) had in vitro antilisterial activity. These results demonstrate that raw sheep milk can be considered an important source of autochthonous thermophilic LAB that can be employed as protective cultures during the manufacturing of Sardinian PDO cheeses to improve their food safety. The use of bioprotective cultures should be seen as an additional procedure useful to improve cheese safety along with the correct application of good hygienic practices during manufacturing and the post-processing stages.

Identification and Selection of Prospective Probiotics for Enhancing Gastrointestinal Digestion: Application in Pharmaceutical Preparations and Dietary Supplements

Our study investigated the effectiveness of 446 strains of lactic acid bacteria (LAB) belonging to different species and isolated from diverse sources (food, human, and animal) as potential probiotic candidates, with the perspective of producing dietary supplements or pharmacological formulations suitable for enhancing gastrointestinal digestion. The survival capability of all the isolates under harsh gastrointestinal tract conditions was evaluated, in which only 44 strains, named high-resistant, were selected for further food digestibility investigations. All 44 strains hydrolyzed raffinose and exhibited amino and iminopeptidase activities but at various extents, confirming species- and strain-specificity. After partial in vitro digestion mimicking oral and gastric digestive phases, food matrices were incubated with single strains for 24 h. Fermented partially digested matrices provided additional functional properties for some investigated strains by releasing peptides and increasing the release of highly bio-accessible free phenolic compounds. A scoring procedure was proposed as an effective tool to reduce data complexity and quantitively characterize the probiotic potential of each LAB strain, which could be more useful in the selection procedure of powerful probiotics.

Influence of anaerobic biotransformation process of agro-industrial waste with Lactobacillus acidophilus on the rheological parameters: case of study of pig manure

This study evaluated the rheological behavior of the pig waste biotransformation process to produce lactic acid (LA) and biomass with Lactobacillus acidophilus in a stirred reactor. In addition, cell growth, carbohydrate consumption, and LA production were measured at three different agitation speeds, 100, 150, and 200 rpm at 37 °C, with a reaction time of 52 h. During the development of the process, the kinetic and rheological parameters were obtained using the logistic, Gompertz, generalized Gompertz, Ostwald de Waele, and Herschel-Bulkley mathematical models, respectively. The substrate used was pig manure, to which molasses was added at 12% v/v to increase the concentration of carbohydrates. The results suggest that mass exchange is favorable at low agitation speeds. Nevertheless, the presence of molasses rich in carbohydrates as a carbon source modifies the characteristics of the fluid, dilatant (n > 1) at the beginning of the process to end up as pseudoplastic (n < 1) due to the addition of exopolysaccharides and the modification of the physical structure of the substrate. This effect was confirmed by the Herschel-Bulkley model, which presented a better fit to the data obtained, in addition to finding a direct relationship between viscosity and pH that can be used as variables for the control of bioconversion processes of pig manure into biomass rich in Lactobacillus acidophilus.

Probiotic fermented whey-milk beverages: Effect of different probiotic strains on the physicochemical characteristics, biological activity, and bioactive peptides

The effect of probiotic strains (Lactobacillus acidophilus La-03 (La-03); Lactobacillus acidophilus La-05 (La-05); Bifidobacterium Bb-12 (Bb-12) or Lacticaseibacillus casei-01 (L. casei-01)) on the characteristics of fermented whey-milk beverages during storage (4 °C, 30 days) was evaluated. The products were assessed for biological and antioxidant activities, physicochemical characteristics, and bioactive peptides. Probiotic addition increased α-amylase and α-glucosidase inhibition and antioxidant activities, mainly at 15 days of storage. L. casei-01 showed higher metabolic activity (higher titratable acidity and lower pH values) and the presence of anti-hypertensive peptides, while La-5 and Bb-12 showed higher α-glucosidase inhibition, improvements in the high saturated hypercholesterolemic index, and peptides with ACE-inhibitory, antimicrobial, immunomodulatory, and antioxidant activities. Our findings suggest that probiotic fermented whey-milk beverages may exert antidiabetic and antioxidant properties, being suggested La-5 or Bb-12 as probiotics and 15 days of storage.

Are Fermented Foods Effective against Inflammatory Diseases?

Fermented foods have been used over the centuries in various parts of the world. These foods are rich in nutrients and are produced naturally using various biological tools like bacteria and fungi. Fermentation of edible foods has been rooted in ancient cultures to keep food for preservation and storage for a long period of time with desired or enhanced nutritional values. Inflammatory diseases like rheumatoid arthritis, osteoarthritis, and chronic inflammatory pain are chronic disorders that are difficult to treat, and current treatments for these disorders fail due to various adverse effects of prescribed medications over a long period of time. Fermented foods containing probiotic bacteria and fungi can enhance the immune system, improve gastrointestinal health, and lower the risk of developing various inflammatory diseases. Foods prepared from vegetables by fermentation, like kimchi, sauerkraut, soy-based foods, or turmeric, lack proper clinical and translational experimental studies. The current review has focused on the effectiveness of various fermented foods or drinks used over centuries against inflammation, arthritis, and oxidative stress. We also described potential limitations on the efficacies or usages of these fermented products to provide an overarching picture of the research field.

Molecular evolution and population genetics of glutamate decarboxylase acid resistance pathway in lactic acid bacteria

Glutamate decarboxylase (GAD) pathway (GDP) is a major acid resistance mechanism enabling microorganisms' survival in low pH environments. We aimed to study the molecular evolution and population genetics of GDP in Lactic Acid Bacteria (LAB) to understand evolutionary processes shaping adaptation to acidic environments comparing species where the GDP genes are organized in an operon structure (Levilactobacillus brevis) versus lack of an operon structure (Lactiplantibacillus plantarum). Within species molecular population genetic analyses of GDP genes in L. brevis and L. plantarum sampled from diverse fermented food and other environments showed abundant synonymous and non-synonymous nucleotide diversity, mostly driven by low frequency changes, distributed throughout the coding regions for all genes in both species. GAD genes showed higher level of replacement polymorphism compared to transporter genes (gadC and YjeM) for both species, and GAD genes that are outside of an operon structure showed even higher level of replacement polymorphism. Population genetic tests suggest negative selection against replacement changes in all genes. Molecular structure and amino acid characteristics analyses showed that in none of the GDP genes replacement changes alter 3D structure or charge distribution supporting negative selection against non-conservative amino acid changes. Phylogenetic and between species divergence analyses suggested adaptive protein evolution on GDP genes comparing phylogenetically distant species, but conservative evolution comparing closely related species. GDP genes within an operon structure showed slower molecular evolution and higher conservation. All GAD and transporter genes showed high codon usage bias in examined LAB species suggesting high expression and utilization of acid resistance genes. Substantial discordances between species, GAD, and transporter gene tree topologies were observed suggesting molecular evolution of GDP genes do not follow speciation events. Distribution of operon structure on the species tree suggested multiple independent gain or loss of operon structure in LABs. In conclusion, GDP genes in LABs exhibit a dynamic molecular evolutionary history shaped by gene loss, gene transfer, negative and positive selection to maintain its active role in acid resistance mechanism, and enable organisms to thrive in acidic environments.

Fermented Supernatants of Lactobacillus plantarum GKM3 and Bifidobacterium lactis GKK2 Protect against Protein Glycation and Inhibit Glycated Protein Ligation

With age, protein glycation in organisms increases continuously. Evidence from many studies shows that the accumulation of glycated protein is highly correlated with biological aging and the development of aging-related diseases, so developing a dietary agent to attenuate protein glycation is very meaningful. Previous studies have indicated that lactic acid bacteria-fermented products have diverse biological activities especially in anti-aging, so this study was aimed to investigate the inhibitory effect of the fermented supernatants of Lactobacillus plantarum GKM3 (GKM3) and Bifidobacterium lactis GKK2 (GKK2) on protein glycation. The results show that GKM3- and GKK2-fermented supernatants can significantly inhibit protein glycation by capturing a glycation agent (methylglyoxal) and/or protecting functional groups in protein against methylglyoxal-induced responses. GKM3- and GKK2-fermented supernatants can also significantly inhibit the binding of glycated proteins to the receptor for advanced glycation end products (RAGE). In conclusion, lactic acid bacteria fermentation products have the potential to attenuate biological aging by inhibiting protein glycation.

Evaluation of the Anticancer and Probiotic Potential of Autochthonous (Wild) Lacticaseibacillus paracasei Strains from New Ecological Niches as a Possible Additive for Functional Dairy Foods

Probiotics such as Lactobacillus spp. could modulate the intestinal microbiota composition, supporting gastrointestinal tract barrier function and benefiting human health. To evaluate the anticancer and probiotic properties of potentially active autochthonous Lacticaseibacillus paracasei strains on proliferating and differentiated enterocytes, human colon adenocarcinoma cell line HT29 was used as a model. The lactic acid bacteria (LAB) were isolated from new ecological niches—mountain anthills populated by redwood ants (Formica rufa L.). Human colorectal adenocarcinoma cells (HT29, ATCC, HTB-38™) were treated for twenty-four hours with supernatants (SNs) derived from four strains of Lacticaseibacillus paracasei: P4, C8, C15 and M2.1. An MTT assay, alkaline phosphatase activity, IAP, Bax and Bcl-2 gene expression analysis (RT-qPCR) and the Bax/Bcl-2 ratio were evaluated. The MTT assay revealed that the observed effects varied among groups. However, 10% neutralized supernatants from P4, C8, C15 and M2.1 strains did not show cytotoxic effects. In contrast to non-differentiated cells, a significant (p < 0.001) rise in ALP activity in all treatments, with an average of 18%, was established in differentiated cells. The IAP expression was remarkably downregulated in the differentiated M2.1 group (p < 0.05) and upregulated in the non-differentiated P4 (p < 0.05) and M2.1 (p < 0.05) groups. The Bax/Bcl-2 quantity expression ratio in P4 was significantly (p < 0.05) upregulated in proliferating cancer cells, but in P4- and M2.1-differentiated cells these values were downregulated (p < 0.05). The obtained results indicate that the isolated L. paracasei strains possess anticancer and probiotic properties and could be used as additives for functional dairy foods and thus benefit human health.

Recent development in the preservation effect of lactic acid bacteria and essential oils on chicken and seafood products

Chicken and seafood are highly perishable owing to the higher moisture and unsaturated fatty acids content which make them more prone to oxidation and microbial growth. In order to preserve the nutritional quality and extend the shelf-life of such products, consumers now prefer chemical-free alternatives, such as lactic acid bacteria (LAB) and essential oils (EOs), which exert a bio-preservative effect as antimicrobial and antioxidant compounds. This review will provide in-depth information about the properties and main mechanisms of oxidation and microbial spoilage in chicken and seafood. Furthermore, the basic chemistry and mode of action of LAB and EOs will be discussed to shed light on their successful application in chicken and seafood products. Metabolites of LAB and EOs, either alone or in combination, inhibit or retard lipid oxidation and microbial growth by virtue of their principal constituents and bioactive compounds including phenolic compounds and organic acids (lactic acid, propionic acid, and acetic acid) and others. Therefore, the application of LAB and EOs is widely recognized to extend the shelf-life of chicken and seafood products naturally without altering their functional and physicochemical properties. However, the incorporation of any of these agents requires the optimization steps necessary to avoid undesirable sensory changes. In addition, toxicity risks associated with EOs also demand the regularization of an optimum dose for their inclusion in the products.

Exploring the Core Microbiota of Four Different Traditional Fermented Beverages from the Colombian Andes

Fermentation is an ancient process used to prepare and preserve food. Currently, fermented beverages are part of the culture of people living in the Colombian Andean Region, and they are a vital part of their cosmology and ancestral vision. Chicha, Forcha, Champús, and Masato are some of the most common Colombian Andes region’s traditional fermented beverages. These drinks come from the fermentation of maize (Zea maize), but other cereals such as wheat or rye, could be used. The fermentation is carried out by a set of bacteria and yeasts that provide characteristic organoleptic properties of each beverage. In this work, the information collected from the metagenomics analyses by sequencing ITS 1-4 (Internal Transcriber Spacer) and the 16S ribosomal gene for fungi and the V3-V4 region of the rDNA for bacteria allowed us to identify the diversity present in these autochthonous fermented beverages made with maize. The sequencing analysis showed the presence of 39 bacterial and 20 fungal genera. In addition, we determined that only nine genera of bacteria and two genera of fungi affect the organoleptic properties of smell, colour, and flavour, given the production of compounds such as lactic acid, alcohol, and phenols, highlighting the critical role of these microorganisms. Our findings provide new insights into the core microbiota of these beverages, represented by Lactobacillus fermentum, Acetobacter pasteurianus, and Saccharomyces cerevisiae.

In vivo functional effects of Weissella confusa VP30 exopolysaccharides on loperamide-induced constipation in rats

In this work, the in vivo functionalities of milk fermented with Weissella confusa VP30 (VP30-EPS) and purified exopolysaccharide (pEPS) from the milk fermented with Weissella confusa VP30 were evaluated for their effect on constipation using an experimental constipated rat model. Rats were randomly divided into four groups: (i) control group (PBS administered normal group), (ii) loperamide treated group (constipation group), (iii) constipation with loperamide plus VP30-EPS (1 g/kg), and (iv) constipation with loperamide plus pEPS (0.6 g/kg) groups. Loperamide treatment induced animal constipation and significantly reduced the frequency of defecation, intestinal transit ratio, and water content of feces. However, all four fecal parameters were improved in both the loperamide plus VP30-EPS and pEPS administered groups as compared to the loperamide group. These results suggest that the addition of VP30-EPS potentially improves the functional laxative effects of commercial products. This study suggests the possibility that VP30-EPS can be applied to fermented and/or functional foods to relieve constipation.

Isolation and Characterization of Lactobacillus paracasei 85 and Lactobacillus buchneri 93 to Absorb and Biotransform Zearalenone

As one of the most prevalent estrogenic mycotoxins in cereals and animal feed, zearalenone (ZEN) can cause serious reproductive disorders. ZEN control in food and feed commodities has been an imperative area of research. In this study, 87 lactic acid bacteria (LAB) were isolated from pickles and their ZEN (5 mg/L) removal abilities ranged from 0% to 68.4%. Then, five strains with potent ZEN removal ability (>50%) were identified: Lactobacillus plantarum 22, L. plantarum 37, L. plantarum 47, L. paracasei 85, and L. buchneri 93. Under optimization conditions (48 h, pH 4.0, 37 °C, and 5 mg/L), the highest ZEN removal abilities of L. paracasei 85 and L. buchneri 93 reached 77.7% and 72.8%, respectively. Moreover, the two lactic acid bacteria decreased the toxicity of ZEN, because the levels of β-zearalenol (β-ZOL) transformed from ZEN were more than two-fold higher than α-zearalenol (α-ZOL). Additionally, cell free supernatant and pellet biotransformation of ZEN to α-ZOL and β-ZOL in LAB were detected for the first time. Furthermore, chemical and enzymatical treatments combined with Fourier-transform infrared spectroscopy analysis indicated that exopolysaccharides, proteins, and lipids on the cell wall could bond to ZEN through hydrophobic interactions. Scanning electron microscopy indicated that cell structure damage occurred during the ZEN clearance to L. buchneri 93, but it did not with L. paracasei 85. In addition, various organic acids, alcohols, and esters of the two LAB participated in ZEN removal. Hence, L. paracasei 85 and L. buchneri 93 can be considered as potential detoxification agents for ZEN removal for food and feedstuff.

Comparison on Protein Bioaccessibility of Soymilk Gels Induced by Glucono-δ-Lactone and Lactic Acid Bacteria

In this study, the protein bioaccessibility of soymilk gels produced by the addition of glu-cono-δ-lactone (GDL) and fermentation with lactic acid bacteria (LAB) was examined using an in vitro gastrointestinal simulated digestion model. The in vitro protein digestibility, soluble protein content, free amino acids contents, degree of hydrolysis, electrophoretic patterns, and peptide content were measured. The results suggested that acid-induced soymilk gel generated by GDL (SG) showed considerably reduced in vitro protein digestibility of 75.33 ± 1.00% compared to the soymilk gel induced by LAB (SL) of 80.57 ± 1.53% (p < 0.05). During the gastric digestion stage, dramatically higher (p < 0.05) soluble protein contents were observed in the SG (4.79−5.05 mg/mL) than that of SL (4.31−4.35 mg/mL). However, during the later intestinal digestion phase, the results were the opposite. At the end of the gastrointestinal digestion phase, the content of small peptides was not significantly different (p > 0.05) between the SL (2.15 ± 0.03 mg/mL) and SG (2.17 ± 0.01 mg/mL), but SL showed higher content of free amino acids (20.637 g/L) than that of SG (19.851 g/L). In general, soymilk gel induced by LAB had a higher protein bioaccessibility than the soymilk gel coagulated by GDL.

Nitrogen source: an effective component for the growth and viability of Lactobacillus delbrueckii subsp. bulgaricus

In this study, we developed and optimized a growth media by evaluating various nitrogen sources for the cultivation of Lactobacillus bulgaricus, a probiotic and an important dairy starter culture. We modified the composition of deMan, Rogosa and Sharpe (MRS) culture media and substituted the nitrogen content with alternative nitrogen sources X-Seed KAT, X-Seed Carbo Max and X-Seed Nucleo Max in various blends of 5 g/l and 10 g/l respectively. Results showed that bacterial growth was significantly higher when the nitrogen source blend KCMax (10/10) was used. The optical density (OD610 nm) of the Lactobacillus bulgaricus strains were higher (1.34 and 1.79) in the KCMax (10/10) medium than in the MRS medium (0.89 and 1.42) (P < 0.05). There was no significant difference in the bacterial counts for both the MRS medium and the KCMax (10/10) medium, and all bacterial counts were estimated at 8 log CFU/ml. The buffering capacity of KCMax (10/10) was also tested and supplemented with l-histidine and was significantly different (P < 0.05) than that of the MRS control medium. Calcium supplemented in the KCMax (10/10) also served as a cryoprotectant for the cells during freezing and freeze-drying. Bacterial counts of the recovered calcium-treated freeze-dried cells were statistically significant (P < 0.05). We hypothesized that alternative nitrogen sources such as selected yeast extracts from the X-Seed brand of complex nitrogen sources could efficiently support the viability of Lb. bulgaricus. Our results thus suggested the growth of Lb. bulgaricus was efficiently supported by the X-Seed KAT, X-Seed Nucleo Max and X-Seed Carbo Max nitrogen sources. Consequently, these alternative nitrogen sources could potentially be recommended for dairy starter culture fermentations.

Development of mixed starter culture for the fermentation of Ethiopian honey wine, Tej

Ethiopian honey wine is one of the country's most popular spontaneously fermented traditional alcoholic beverages. However, the final product of this natural fermentation system is frequently of poor and inconsistent quality. Furthermore, it makes the process difficult to predict, control, and correct. Thus, the main aim of this study was to develop a direct fermentation system for Ethiopian honey wine, Tej. After isolating fermentative microbial strains from Tej samples, they were subjected to intensive screening to fit to its purpose. Later, phenotypic and genotypic characterization, and inoculation of isolates to honey-must were performed sequentially. Finally, microbial interaction and physicochemical analysis, including volatile compounds profiling, were done for the inoculated samples. The identified isolates were strains of Saccharomycetaceae and Lactobacillaceae families. These strains showed a good ability to tolerate osmotic stress and a lower pH environment. Tej sample produced by mixed culture inoculation of Saccharomyces and Lactobacillus species showed similar physicochemical, volatile compounds, and sensory attributes values with that of the control sample. Thus, a mixture of Saccharomyces and Lactobacillus strains could be used as a starter culture to produce Ethiopian honey, Tej, without scarifying of its major quality attributes.

Characterization of exopolysaccharide produced by Levilactobacillus brevis HDE-9 and evaluation of its potential use in dairy products

The bacterial strain HDE-9 was isolated from sauerkraut and identified as Levilactobacillus brevis. An exopolysaccharide (EPS) was isolated and purified from L. brevis HDE-9, and a preliminary investigation of its structural characteristics and biological activity was conducted. The molecular weight of the EPS was >1.0 × 10⁶ Da. Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy revealed that the EPS was composed of α-(1 → 6) linked d-glucopyranose units. X-ray diffraction (XRD) data on the EPS revealed its non-crystalline amorphous structure. Scanning electron microscopy (SEM) of the EPS revealed a smooth surface with sheet structures. The EPS exhibited the high value in thermal stability, water solubility, water holding capacity (WHC), and emulsification activity (EA). The water contact angle of the EPS revealed relatively high hydrophobicity in the presence of sucrose. The EPS also showed a strong milk solidification capacity in a dose-dependent manner. The EPS could significantly improve the texture of yoghurt, indicating its potential application as a functional starter in the production of fermented dairy products.

Plasmid-Based Gene Expression Systems for Lactic Acid Bacteria: A Review

Lactic acid bacteria (LAB) play a very vital role in food production, preservation, and as probiotic agents. Some of these species can colonize and survive longer in the gastrointestinal tract (GIT), where their presence is crucially helpful to promote human health. LAB has also been used as a safe and efficient incubator to produce proteins of interest. With the advent of genetic engineering, recombinant LAB have been effectively employed as vectors for delivering therapeutic molecules to mucosal tissues of the oral, nasal, and vaginal tracks and for shuttling therapeutics for diabetes, cancer, viral infections, and several gastrointestinal infections. The most important tool needed to develop genetically engineered LABs to produce proteins of interest is a plasmid-based gene expression system. To date, a handful of constitutive and inducible vectors for LAB have been developed, but their limited availability, host specificity, instability, and low carrying capacity have narrowed their spectrum of applications. The current review discusses the plasmid-based vectors that have been developed so far for LAB; their functionality, potency, and constraints; and further highlights the need for a new, more stable, and effective gene expression platform for LAB.

Effect of Lactic Acid Fermentation on Legume Protein Properties, a Review

Legume proteins have a promising future in the food industry due to their nutritional, environmental, and economic benefits. However, their application is still limited due to the presence of antinutritional and allergenic compounds, their poor technological properties, and their unpleasant sensory characteristics. Fermentation has been traditionally applied to counteract these inconveniences. At present, lactic acid fermentation of legumes is attracting the attention of researchers and industry in relation to the development of healthier, tasty, and technologically adapted products. Hence, we aimed to review the literature to shed light on the effect of lactic acid fermentation on legume protein composition and on their nutritional, functional, technological, and sensorial properties. The antimicrobial activity of lactic acid bacteria during legume fermentation was also considered. The heterogenicity of raw material composition (flour, concentrate, and isolate), the diversity of lactic acid bacteria (nutriment requirements, metabolic pathways, and enzyme production), and the numerous possible fermenting conditions (temperature, time, oxygen, and additional nutrients) offer an impressive range of possibilities with regard to fermented legume products. Systematic studies are required in order to determine the specific roles of the different factors. The optimal selection of these criteria will allow one to obtain high-quality fermented legume products. Fermentation is an attractive technology for the development of legume-based products that are able to satisfy consumers’ expectations from a nutritional, functional, technological, and sensory point of view.

An Assessment of the Lactic Acid-Producing Potential of Bacterial Strains Isolated from Food Waste

Lactic acid (LA) is widely used in many industries as a crucial starting material in food products, bio-based materials, and biodegradable polymers. The goals of this research were to isolate LA bacteria from food wastes, assess their potential for LA production, and study their growth characteristics. In this study, six bacterial strains were isolated from food waste and identified using 16S rRNA gene sequencing; namely, Weissella viridescens WJ39, Leuconostoc lactis YS33, Leuconostoc citreum KD42, Leuconostoc mesenteroides VN60, Macrococcus caseolyticus FCI29, and Weissella confusa RG41. W. viridescens WJ39 showed the highest potential for lactic acid production (17.56 g L−1day−1), and the lowest potential was found in L. lactis YS33 (14.09 g L−1day−1). There were significant differences (p < 0.05) in the LA production rates among Weissella spp., Leuconostoc spp., and Macrococcus spp. Moreover, dramatic differences in growth rate were observed among the six strains. W. viridescens WJ39 exhibited the highest growth rate (0.80 h−1), while M. caseolyticus FCI29 exhibited the lowest growth rate (0.57 h−1). W. viridescens WJ39 also exhibited lactic acid production (at a rate around 2 g L−1day−1) in a lab incubation experiment with food waste as a nutrient source. The draft genome of W. viridescens WJ39 with 16 contigs was constructed with an N50 of 215217 bp. The genome size was approximately 1.54 Mb, with a GC content of 41%. A hicD gene, known to catalyze the conversion of pyruvate to D-lactate, was discovered in the genome. This study illustrated the potential for the production of lactic acid from food waste with lactic acid bacteria.

Functional characterization of α-Gal producing lactic acid bacteria with potential probiotic properties

The possibility of exploiting the human immune response to glycan α-Gal for the control of multiple infectious diseases has been the objective of recent investigations. In this field of research, the strain of Escherichia coli O86:B7 has been at the forefront, but this Gram-negative microorganism presents a safety concern and therefore cannot be considered as a probiotic. To address this challenge, this study explored the identification of novel lactic acid bacteria with a safe history of use, producing α-Gal and having probiotic potential. The lactic acid bacteria were isolated from different traditionally fermented foods (kununn-zaki, kindirmo, and pulque) and were screened for the production of α-Gal and some specific probiotic potential indicators. The results showed that Ten (10) out of forty (40) [25%] of the tested lactic acid bacteria (LAB) produced α-Gal and were identified as Limosilactobacillus fermentum, Levilactobacillus brevis, Agrilactobacillus composti, Lacticaseibacillus paracasei, Leuconostoc mesenteroides and Weissella confusa. Four (4) LAB strains with highest levels of α-Gal were further selected for in vivo study using a mouse model (α1,3GT KO mice) to elucidate the immunological response to α-Gal. The level of anti-α-Gal IgG observed were not significant while the level of anti-α-Gal IgM was lower in comparison to the level elicited by E. coli O86:B7. We concluded that the lactic acid bacteria in this study producing α-Gal have potential probiotic capacity and can be further explored in α-Gal-focused research for both the prevention and treatment of various infectious diseases and probiotic development.

Comparative genomics reveals the organic acid biosynthesis metabolic pathways among five lactic acid bacterial species isolated from fermented vegetables

Lactic acid bacteria (LAB) comprise a widespread bacterial group, inhabiting the niches of fermented vegetables and capable of producing beneficial organic acids. In the present study, several bioinformatics approaches were used to perform whole-genome sequencing and comparative genomics of five LAB species, Lactobacillus plantarum PC1-1, Pediococcus pentosaceus PC2-1(F2), Weissella hellenica PC1A, Lactobacillus buchneri PC-C1, and Enterococcus sp. YC2-6, to enhance understanding of their different genetic functionalities and organic acid biosynthesis. The results revealed major carbohydrate-active enzymes, putative operons and unique mobile genetic elements, including plasmids, resistance genes, insertion sequences and composite transposons involved in organic acid biosynthesis. The metabolic pathways of organic acid biosynthesis emphasize the key genes encoding specific enzymes required for organic acid metabolism. The five genomes were found to contain various regions of secondary metabolite biosynthetic gene clusters, including the type III polyketide synthases (T3PKS) enriched with unique genes encoding a hydroxymethylglutaryl-CoA synthase, capable of exhibiting specific antimicrobial activity with biopreservative potential, and a cyclic AMP receptor protein (CPR) transcription factor acting as a glucose sensor in organic acid biosynthesis. This could enable the organisms to prevail in the fermentation process, suggesting potential industrial applications.

Role of Lactic Acid Bacteria in Food Preservation and Safety

Fermentation of various food stuffs by lactic acid bacteria is one of the oldest forms of food biopreservation. Bacterial antagonism has been recognized for over a century, but in recent years, this phenomenon has received more scientific attention, particularly in the use of various strains of lactic acid bacteria (LAB). Certain strains of LAB demonstrated antimicrobial activity against foodborne pathogens, including bacteria, yeast and filamentous fungi. Furthermore, in recent years, many authors proved that lactic acid bacteria have the ability to neutralize mycotoxin produced by the last group. Antimicrobial activity of lactic acid bacteria is mainly based on the production of metabolites such as lactic acid, organic acids, hydroperoxide and bacteriocins. In addition, some research suggests other mechanisms of antimicrobial activity of LAB against pathogens as well as their toxic metabolites. These properties are very important because of the future possibility to exchange chemical and physical methods of preservation with a biological method based on the lactic acid bacteria and their metabolites. Biopreservation is defined as the extension of shelf life and the increase in food safety by use of controlled microorganisms or their metabolites. This biological method may determine the alternative for the usage of chemical preservatives. In this study, the possibilities of the use of lactic acid bacteria against foodborne pathogens is provided. Our aim is to yield knowledge about lactic acid fermentation and the activity of lactic acid bacteria against pathogenic microorganisms. In addition, we would like to introduce actual information about health aspects associated with the consumption of fermented products, including probiotics.

Properties of Rice-Based Beverages Fermented with Lactic Acid Bacteria and Propionibacterium

In recent times, consumers have shown increasing interest in plant substitutes for fermented dairy products. This study aimed to investigate the properties of yogurt-type rice-based beverages fermented with lactic acid bacteria and Propionibacterium. The changes in pH, viable population of bacteria, physical properties, and carbohydrate content of these beverages were tested. Fermentation using only Propionibacterium was insufficient to obtain a product with an acidity level similar to that of milk-based yogurt (pH < 4.5). After fermentation, the tested beverages had a high number of Lactobacillus sp. (7.42−8.23 log10 CFU/mL), Streptococcus thermophilus (8.01−8.65 log10 CFU/mL), and Bifidobacterium animalis subsp. lactis (8.28−8.50 log10 CFU/mL). The hardness (2.90−10.40 N) and adhesiveness (13.79−42.16 mJ) of the samples after 14 days of storage at 6 °C varied depending on the starter culture used. The syneresis of all samples ranged between 29% and 31%, which was lower or close to that of milk-based yogurts. The content of individual sugars in the samples also varied depending on the starter culture used for fermentation. The results suggest that the combination of lactic and propionic fermentation helps in the production of rice-based yogurt-type milk substitutes.

Functional Properties and Antimicrobial Activity from Lactic Acid Bacteria as Resources to Improve the Health and Welfare of Honey Bees

Simple Summary

Honey bees play a pivotal role in the sustainability of ecosystems and biodiversity. Many factors including parasites, pathogens, pesticide residues, forage losses, and poor nutrition have been proposed to explain honey bee colony losses. Lactic acid bacteria (LAB) are normal inhabitants of the gastrointestinal tract of honey bees and their role has been consistently reported in the literature. In recent years, there have been numerous scientific evidence that the intestinal microbiota plays an essential role in honey bee health. Management strategies, based on supplementation of the gut microbiota with probiotics, may be important to increase stress tolerance and disease resistance. In this review, recent scientific advances on the use of LABs as microbial supplements in the diet of honey bees are summarized and discussed.

Abstract

Honey bees (Apis mellifera) are agriculturally important pollinators. Over the past decades, significant losses of wild and domestic bees have been reported in many parts of the world. Several biotic and abiotic factors, such as change in land use over time, intensive land management, use of pesticides, climate change, beekeeper’s management practices, lack of forage (nectar and pollen), and infection by parasites and pathogens, negatively affect the honey bee’s well-being and survival. The gut microbiota is important for honey bee growth and development, immune function, protection against pathogen invasion; moreover, a well-balanced microbiota is fundamental to support honey bee health and vigor. In fact, the structure of the bee’s intestinal bacterial community can become an indicator of the honey bee’s health status. Lactic acid bacteria are normal inhabitants of the gastrointestinal tract of many insects, and their presence in the honey bee intestinal tract has been consistently reported in the literature. In the first section of this review, recent scientific advances in the use of LABs as probiotic supplements in the diet of honey bees are summarized and discussed. The second section discusses some of the mechanisms by which LABs carry out their antimicrobial activity against pathogens. Afterward, individual paragraphs are dedicated to Chalkbrood, American foulbrood, European foulbrood, Nosemosis, and Varroosis as well as to the potentiality of LABs for their biological control.

The Acrylamide Degradation by Probiotic Strain Lactobacillus acidophilus LA-5

Acrylamide is a harmful substance produced in thermal processed food; however, it can also be found in food with various additives. The aim of the study was to check whether the probiotic bacteria strain, Lactobacillus acidophilus LA-5 (LA5), can degrade acrylamide and hence reduce its concentration in foodstuff. Our results revealed that LA5 can degrade acrylamide and cause a decrease in its concentration, but only when other available carbon and nitrogen sources are lacking. In the presence of casein, lactose, milk fat or in whole cow’s milk, this ability disappeared. Acrylamide present in milk, however, modulated the bacteria metabolism by significantly enhancing lactic acid production by LA5 in milk (at conc. 100 µg/mL), while the production of acetic acid was rather reduced.

Consumer's acceptability and health consciousness of probiotic and prebiotic of non-dairy products

Human gut microbiota is a protective agent of intestinal and systemic health, and its modulation is of great interest for human wellbeing. In the world of biotics, besides probiotics, prebiotics, and synbiotics, also appears the denomination of "postbiotics" and "psychobiotics". Fermented dairy products are, traditionally, the major source of probiotics. Nevertheless, due to the increasing number of lactose-intolerant individuals and strict vegetarians, there is a need for innovative non-dairy products. Non-dairy biotics are being included in the normal diet and due to technological advances, many products are created using non-conventional food matrices like kombucha tea, herbal tea, baking mix, and cereal-based products. The microorganisms most used as probiotics in many of the non-dairy products are strains belonging to the genera Bifidobacterium, Enterococcus, Lactobacillus, Lactococcus, Streptococcus, and Bacillus, and some yeast strains namely Saccharomyces cerevisiae var. boulardii. Recently, several other yeasts have been described as having probiotic properties. This review describes gut-derived effects in humans of possible microorganisms, such as yeasts, and bacteria, isolated from non-dairy fermented and non-fermented foods and beverages. The microorganisms responsible for the processing of these non-dairy fermented products, together with the prebiotics, form a class of nutrients that have been proven to be beneficial for our gut health.

Bifidobacterium animalis subsp. lactis HN019 Effects on Gut Health: A Review

Optimal gut motility is central to bowel function and gut health. The link between the gut dysmotility related disorders and dysfunctional-intestinal barriers has led to a hypothesis that certain probiotics could help in normalizing gut motility and maintain gut health. This review investigates the roles of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019™) on gut health, and its mechanisms of action in various pre-clinical and clinical studies. Research supports the hypothesis that B. lactis HN019™ has a beneficial role in maintaining intestinal barrier function during gastrointestinal infections by competing and excluding potential pathogens via different mechanisms; maintaining normal tight junction function in vitro; and regulating host immune defense toward pathogens in both in vitro and human studies. This has been observed to lead to reduced incidence of diarrhea. Interestingly, B. lactis HN019™ also supports normal physiological function in immunosenescent elderly and competes and excludes potential pathogens. Furthermore, B. lactis HN019™ reduced intestinal transit time and increased bowel movement frequency in functional constipation, potentially by modulating gut–brain–microbiota axis, mainly via serotonin signaling pathway, through short chain fatty acids derived from microbial fermentation. B. lactis HN019™ is thus a probiotic that can contribute to relieving gut dysmotility related disorders.

Legumes and Legume-Based Beverages Fermented with Lactic Acid Bacteria as a Potential Carrier of Probiotics and Prebiotics

Fermentation is widely used in the processing of dairy, meat, and plant products. Due to the growing popularity of plant diets and the health benefits of consuming fermented products, there has been growing interest in the fermentation of plant products and the selection of microorganisms suitable for this process. The review provides a brief overview of lactic acid bacteria (LAB) and their use in fermentation of legumes and legume-based beverages. Its scope also extends to prebiotic ingredients present in legumes and legume-based beverages that can support the growth of LAB. Legumes are a suitable matrix for the production of plant-based beverages, which are the most popular products among dairy alternatives. Legumes and legume-based beverages have been successfully fermented with LAB. Legumes are a natural source of ingredients with prebiotic properties, including oligosaccharides, resistant starch, polyphenols, and isoflavones. These compounds provide a broad range of important physiological benefits, including anti-inflammatory and immune regulation, as well as anti-cancer properties and metabolic regulation. The properties of legumes make it possible to use them to create synbiotic food, which is a source of probiotics and prebiotics.