Search

Aim: A comprehensive safety assessment of potential probiotic strains was essential for their application in the food industry. This article systematically evaluated the probiotic characteristics, whole-genome sequence analysis and safety of Lacticaseibacillus paracasei LC86 and Lacticaseibacillus casei LC89. Methods: Firstly, the two strains of lactic acid bacteria selected were identified. Secondly, whole-genome sequencing was performed on LC86 and LC89, and their antibiotic resistance, pathogenicity, and virulence genes were analyzed. We tested various properties of the two strains, included tolerance, cell adhesion, hemolytic activity, catalase activity, gelatin hydrolysis, arginine hydrolysis ability, bile salt hydrolysis capacity, mucin degradation, bioamine, D-/L-lactic acid production and antibiotic susceptibility, to confirm the safety of LC86 and LC89 both in vitro and in vivo. Additionally, we studied the acute toxicity of LC86 and LC89 in mice through a 14-day oral gavage experiment. Results: The two strains selected were identified as Lacticaseibacillus paracasei and Lacticaseibacillus casei. The genomes of both LC86 and LC89 were devoid of virulence, antibiotic resistance and pathogenicity genes. LC86 and LC89 exhibited good tolerance to temperature, artificial gastric fluid and artificial intestinal fluid; they were non-hemolytic, their catalase activity, gelatin hydrolysis, arginine hydrolysis and bile salt hydrolysis were all negative. They exhibited the capability to break down proteins and demonstrated sensitivity to a range of antibiotics. The oral LD50 for both LC86 and LC89 in mice was >2 × 1010 CFU/kg. Conclusion: The experimental results above demonstrated the probiotic characteristics and safety of LC86 and LC89, indicating their potential as candidates for probiotics for human and animal applications. [ABSTRACT FROM AUTHOR]

The present research evaluated the effect of selected Lacticaseibacillus casei strains with anti-Listeria monocytogenes properties on the characteristics of traditional soft-ripened cheeses produced in two different seasons. Physicochemical, microbiological, texture, volatile compound, and sensory evaluations were performed on the cheeses after 60 days of ripening. The inoculation with protective cultures of selected LAB did not negatively affect the physicochemical parameters of the cheeses. Thirty-two volatile compounds were identified, including acids, alcohols, ketones, aldehydes, and esters, with differences between productions and inoculated batches. The selected LAB strains improved the sensory profile of the soft-ripened cheeses, decreasing values of texture parameters such as hardness, gumminess, and chewiness related to a softer texture and increasing umami taste and floral and lactic odor attributes. Sensory analysis revealed that consumers perceived differences between inoculated and non-inoculated cheeses, although the overall acceptability was not affected. This study provides valuable information for the artisanal cheese industry, demonstrating that it is possible to use selected protective lactic acid bacteria to assure food safety without compromising traditional flavor and even improving sensorial attributes. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of the dynamics of growth and metabolism of Lacticaseibacillus casei production strains in model milk media and semi-hard cheeses. In dairy media under optimal conditions, the maximum number of viable cells of the studied Lacticaseibacillus casei strains was achieved on day 3; an increase in titratable acidity continued for up to 7‒10 days. In model dairy media simulating cheese ripening conditions, the growth and metabolism (glycolysis, proteolysis, and production of volatile aroma compounds) of Lacticaseibacillus casei slowed down. In semi-hard cheeses, the Lacticaseibacilluscasei culture (as an independent acid-generating starter component), did not provide the required intensity of acid formation during the production process. However, as an adjunct culture, it intensified proteolysis and the processes of gas and aroma formation during ripening, thus, improving the organoleptic characteristics of cheeses. [ABSTRACT FROM AUTHOR]

Vine tea extract (VTE), from the traditional Chinese herbal tea, was added to reconstituted skimmed milk; the mixture was fermented with Lacticaseibacillus casei, and fermentation characteristics, flavonoid content, antioxidant capacity (AOC), and viability of L. casei were measured. 2 mg/mL VTE promoted L. casei growth and 8 mg/mL VTE inhibited growth, an effect consistent with observed pH changes. Total flavonoid content and AOC increased with increasing VTE dosage. Dihydromyricetin was partially metabolized during fermentation and accounted for most of the antioxidant function of VTE. 2 mg/mL VTE was optimal for maintenance of probiotic culture and pH stability during cold storage and improved AOC during product shelf life. VTE has the potential to increase the health benefits of probiotic dairy products, and the resulting mixture may be suitable to use as a daily milk‐based health drink. [ABSTRACT FROM AUTHOR]

Background: The increasing prevalence of plant-based dietary preferences, driven by lactose intolerance, allergies, and adherence to vegan diets, has necessitated the exploration of alternative food matrices for probiotic delivery. Objectives: This study aimed to evaluate the effects of whey protein isolate, pea protein isolate, and soy protein isolate on the viability of L. casei and L. johnsonii during simulated in vitro gastrointestinal digestion. Furthermore, the study investigated the impact of two distinct matrices—cow's milk and an oat-based beverage—on the survival of these probiotic strains. Fermented products were prepared using cow's milk and an oat-based beverage as matrices, with simulated digestion performed following a seven-day storage period at 5 °C. The in vitro digestion model encompassed oral, gastric, and small intestinal phases, with probiotic viability assessed using the plate-deep method at each stage. Methods: Before digestion, L. casei exhibited higher populations than L. johnsonii in both matrices. Including 3% soy and pea protein, isolates promoted the growth of L. casei in both fermented milk and oat beverages. However, a marked reduction in probiotic viability was observed during the gastric phase, with L. casei counts decreasing by 6.4–7.8 log cfu g−1 in fermented milk and 3.1–4 log cfu g−1 in oat beverages, while L. johnsonii demonstrated similar reductions. Conclusion: These findings underscore the protective role of dairy components on probiotic viability, while the oat-based matrix exhibited a reduced capacity for sustaining probiotic populations throughout digestion. Future research should focus on optimizing plant-based matrices to enhance probiotic stability during gastrointestinal transit. [ABSTRACT FROM AUTHOR]

Incorporating plant protein isolates into milk can enhance probiotic culture growth by providing essential nutrients and altering the physicochemical properties of fermented milk. This study investigated the effects of adding 1.5% or 3.0% soy, pea, and whey protein isolates on the growth of Lacticaseibacillus casei and Lactobacillus johnsonii monocultures, as well as the physicochemical (acidity, syneresis, color) and organoleptic properties of fermented milk during 21 days of refrigerated storage. The results showed that 1.5% SPI and WPI did not significantly alter milk acidity compared to controls. Still, pH increased with 1.5% and 3.0% PPI. Storage time significantly affected pH in L. casei fermented milk. The initial addition of WPI at 1.5% and 3.0% reduced syneresis in L. casei fermented milk compared to other samples. Color components were significantly influenced by isolates. Initial L. casei cell counts were lower with SPI (LCS1.5 and LCS3) and 1.5% PPI (LCP1.5) compared to controls. Increasing isolate concentration from 1.5% to 3% enhanced L. johnsonii growth in WPI-milk but reduced L. casei in LCW3 compared to LCW1.5. Only increased pea protein concentration significantly increased L. casei growth. Probiotic populations generally were reduced during extended storage. Moreover, isolates impacted milk organoleptic evaluation. This research demonstrates the potential of protein isolates in creating health-promoting and diverse fermented products and offers insights into their interaction with probiotic cultures to advance functional food technologies. [ABSTRACT FROM AUTHOR]

In this study, Lacticaseibacillus casei and Lactobacillus acidophilus probiotic bacteria were encapsulated using oleaster flour, which is rich in phenolic compounds and has prebiotic properties as potential. The optimum conditions required for the encapsulation of L. casei and L. acidophilus bacteria with maximum efficiency using oleaster flour were determined by central composite design–response surface methodology. As a result of the optimization process, the encapsulation efficiency for L. casei and L. acidophilus capsules was 93.66 ± 2.58% and 74.97 ± 1.34%, respectively. The capsule sizes of L. casei and L. acidophilus encapsulated with oleaster flour were determined by scanning electron microscopy to be 104.8 ± 26.3 and 95.7 ± 12.1 μm, respectively. Fourier transform infrared spectroscopy analyses showed that there was no change in the structure of the encapsulation material, oleaster flour, after encapsulation. Also, the storage stability of free and encapsulated bacteria was investigated, and it was found that the viability losses of encapsulated probiotic bacteria were less than those of free probiotic bacteria. Finally, the effect of encapsulation on bacterial viability during in vitro gastrointestinal digestion was investigated, which is the main purpose of the study. While free probiotic bacteria cannot reach the intestinal environment alive after in vitro gastrointestinal digestion due to pH and enzyme effects, encapsulated L. casei and L. acidophilus bacteria largely preserved their viability, and their postdigestion viability was 39.59 ± 1.50% and 36.28 ± 0.01%, respectively. The results showed successful encapsulation of L. casei and L. acidophilus probiotic bacteria with oleaster flour. [ABSTRACT FROM AUTHOR]

AimA comprehensive safety assessment of potential probiotic strains was essential for their application in the food industry. This article systematically evaluated the probiotic characteristics, whole-genome sequence analysis and safety of Lacticaseibacillus paracasei LC86 and Lacticaseibacillus casei LC89.MethodsFirstly, the two strains of lactic acid bacteria selected were identified. Secondly, whole-genome sequencing was performed on LC86 and LC89, and their antibiotic resistance, pathogenicity, and virulence genes were analyzed. We tested various properties of the two strains, included tolerance, cell adhesion, hemolytic activity, catalase activity, gelatin hydrolysis, arginine hydrolysis ability, bile salt hydrolysis capacity, mucin degradation, bioamine, D-/L-lactic acid production and antibiotic susceptibility, to confirm the safety of LC86 and LC89 both in vitro and in vivo. Additionally, we studied the acute toxicity of LC86 and LC89 in mice through a 14-day oral gavage experiment.ResultsThe two strains selected were identified as Lacticaseibacillus paracasei and Lacticaseibacillus casei. The genomes of both LC86 and LC89 were devoid of virulence, antibiotic resistance and pathogenicity genes. LC86 and LC89 exhibited good tolerance to temperature, artificial gastric fluid and artificial intestinal fluid; they were non-hemolytic, their catalase activity, gelatin hydrolysis, arginine hydrolysis and bile salt hydrolysis were all negative. They exhibited the capability to break down proteins and demonstrated sensitivity to a range of antibiotics. The oral LD50 for both LC86 and LC89 in mice was >2 × 1010 CFU/kg.ConclusionThe experimental results above demonstrated the probiotic characteristics and safety of LC86 and LC89, indicating their potential as candidates for probiotics for human and animal applications.

The demand for plant-based proteins as alternative meat sources continues to increase because of environmental concerns, animal welfare, and religious reasons. However, plant-based proteins have low digestibility than real meat, which should be overcome. In the present study, the effect of co-administration of legumin protein mixture and the probiotic strain on plasma concentration of amino acids was investigated as a strategy of enhancement in protein digestion. First, the proteolytic activity of the four probiotic strains was compared. As a result, Lacticaseibacillus casei IDCC 3451 was identified as an optimal probiotic strain that efficiently digested the legumin protein mixture by forming the largest halo produced by proteolysis. Next, to investigate whether the co-administration of legumin protein mixture and L. casei IDCC 3451 could synergically improve digestibility, mice were fed either a high-protein diet or a high-protein diet with L. casei IDCC 3451 for 8 weeks. Compared to only in the high-protein diet only group, the concentrations of branched chain amino acids and essential amino acids were 1.36 and 1.41 times higher in the co-administered group, respectively. Therefore, co-supplementation of plant-based proteins with L. casei IDCC 3451 can be suggested to improve protein digestibility based on the this study. [ABSTRACT FROM AUTHOR]

Background: Postbiotics comprise soluble compounds freed from the structure of destroyed bacteria or created by living bacteria. Such byproducts provide the host with enhanced biological function as well as specific physiological consequences. This research aims to examine the characteristics and possible health advantages of -derived postbiotics. Methods: The antibacterial effects of postbiotics derived from were examined in vitro against various infectious gastrointestinal agents, as well as pasteurized milk and minced beef. Postbiotic activity potential was evaluated using disc-diffusion agar, minimum inhibitory concentration, minimum bactericidal concentration, and well-diffusion agar methods. Postbiotics were tested for antioxidant activity against zinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals. Additionally, the total phenolic and flavonoid content of the postbiotics was determined. The colorimetric MTT was used to investigate the potential cytotoxicity of postbiotics. The chemical makeup of the postbiotics was also determined using gas chromatography/mass spectrometry. Results: The antibacterial capacity was mostly related to pyrrolo[1,2-a] pyrazine-1,4-dione, benzoic acid, and laurostearic acid. Gram-positive microbes were more influenced by microbial byproducts in vitro than Gram-negative bacteria (P

Abstract This study aimed to investigate the biological activities of Lactobacillus gasseri SM 05 (L. gasseri) and Lacticaseibacillus casei subsp. casei PTCC 1608 (L. casei) in the black raspberry (Rubus dolichocarpus) juice (BRJ) environment, and also the anti-adhesion activity against Salmonella typhimurium (S. typhimurium) in fermented black raspberry juice (FBRJ). Results showed significant anti-adhesion activity in Caco-2 epithelial cells. In the anti-adhesion process, lactic acid bacteria (LAB) improve intestinal health by preventing the adhesion of pathogens. Adding LAB to BRJ produces metabolites with bacteriocin properties. Major findings of this research include improved intestinal health, improved antidiabetic properties, inhibition of degradation of amino acids, and increase in the nutritional value of foods that have been subjected to heat processing by preventing Maillard inhibition, and inhibition of oxidation of foodstuff by increased antioxidant activity of BRJ. Both species of Lactobacillus effectively controlled the growth of S. typhimurium during BRJ fermentation. Moreover, in all tests, as well as Maillard's and α-amylase inhibition, L. gasseri was more effective than L. casei. The phenolic and flavonoid compounds increased significantly after fermentation by both LAB (p

The present research evaluated the effect of selected Lacticaseibacillus casei strains with anti-Listeria monocytogenes properties on the characteristics of traditional soft-ripened cheeses produced in two different seasons. Physicochemical, microbiological, texture, volatile compound, and sensory evaluations were performed on the cheeses after 60 days of ripening. The inoculation with protective cultures of selected LAB did not negatively affect the physicochemical parameters of the cheeses. Thirty-two volatile compounds were identified, including acids, alcohols, ketones, aldehydes, and esters, with differences between productions and inoculated batches. The selected LAB strains improved the sensory profile of the soft-ripened cheeses, decreasing values of texture parameters such as hardness, gumminess, and chewiness related to a softer texture and increasing umami taste and floral and lactic odor attributes. Sensory analysis revealed that consumers perceived differences between inoculated and non-inoculated cheeses, although the overall acceptability was not affected. This study provides valuable information for the artisanal cheese industry, demonstrating that it is possible to use selected protective lactic acid bacteria to assure food safety without compromising traditional flavor and even improving sensorial attributes.

Currently, the Agave genus has a high economic importance because due to the products that can be obtained from these plants, with alcoholic beverage production being the most common use. The principal storage carbohydrates of agave are fructans. In this study, the utilization of Agave salmiana (green agave) and Agave atrovirens (ashy agave) bagasse cookies as a carbon source by lactic acid‐producing bacteria (LAB), as well as the acceptability of cookies by consumers was evaluated. The cookies were manufactured and digested in vitro, and fermentation by LAB was performed to evaluate pH changes, bacterial growth, and relative carbohydrate intake. The results showed that the bacteria assimilated the digested agave cookies as a carbon source, and there was no significant difference in the pH of both agave bagasse and the growth of Lacticaseibacillus casei. The highest bacterial growth of the L. lactis was observed at 12 h with green bagasse cookies. The results obtained in the present study demonstrate the potential of agave bagasse to be used as functional food ingredients. [ABSTRACT FROM AUTHOR]

The effect of selected autochthonous Lactic Acid Bacteria (LAB) against Listeria monocytogenes was evaluated in two elaborations of soft-ripened cheese performed under high and low relative humidity (RH) elaborations, to achieve aw ranging from 0.97 to 0.94 in ripened cheeses. Two selected autochthonous strains of Lacticaseibacillus casei 31 and 116 were used. In each elaboration, 8 batches were physicochemically and microbiologically evaluated throughout the ripening process. The aw and pH decreased during ripening to final values ranging from 0.944 to 0.972 aw and 5.0 to 5.3 pH, respectively. LAB was the only microbial group that increased throughout the ripening in high and low RH elaborations. In batches that were uninoculated with LAB strains, L. monocytogenes was either maintained at the initial inoculation level or showed a slight reduction by the end of the ripening process. However, in LAB-inoculated batches in the two elaborations, steady decreases of L. monocytogenes were observed throughout maturation. L. casei 31 alone or in combination with strain 116 provoked reductions of 2 to 4 log CFU/g in L. monocytogenes over 60 days of ripening, which could be enough as a strategy for biocontrol to deal with the usual contamination by L. monocytogenes during cheese processing. [ABSTRACT FROM AUTHOR]

Kawasaki disease (KD) is the leading cause of acquired heart disease among children. Murine and human data suggest that the NLRP3-IL-1β pathway is the main driver of KD pathophysiology. NLRP3 can be activated during defective autophagy/mitophagy. We used the Lactobacillus casei cell wall extract (LCWE) murine model of KD vasculitis to examine the role of autophagy/mitophagy on cardiovascular lesion development. LCWE-injected mice had impaired autophagy/mitophagy and increased levels of ROS in cardiovascular lesions, together with increased systemic 8-OHdG release. Enhanced autophagic flux significantly reduced cardiovascular lesions in LCWE-injected mice, whereas autophagy blockade increased inflammation. Vascular smooth muscle cell-specific deletion of Atg16l1 and global Parkin-/- significantly increased disease formation, supporting the importance of autophagy/mitophagy in this model. Ogg1-/- mice had significantly increased lesions with increased NLRP3 activity, whereas treatment with MitoQ reduced vascular tissue inflammation, ROS production, and systemic 8-OHdG release. Treatment with MN58b or Metformin (increasing AMPK and reducing ROS) resulted in decreased cardiovascular lesions. Our results demonstrate that impaired autophagy/mitophagy and ROS-dependent damage exacerbate the development of murine KD vasculitis. This pathway can be efficiently targeted to reduce disease severity. These findings enhance our understanding of KD pathogenesis and identify potentially novel therapeutic avenues for KD treatment.

Lacticaseibacillus casei are commonly utilized as probiotic in a wide-range of fermented and unfermented dairy products. The stability of probiotics in fermented dairy products during shelf-life is of concern due to low pH and high level of organic acids. The objective of this study is to evaluate L. casei for their ability to survive in a model yogurt and fluid milk; additionally, their impact on the pH, organic acids, and sensory attributes of these products was examined. The strain-to-strain differences in cell densities in yogurt and milk inoculated at a therapeutic level at the end of shelf-life were 1.2 and 1.4 log CFU/mL, respectively. Five of the strains examined increased the pH of the yogurt, while two strains were observed to reduce the pH. In milk, one strain raised the pH, while eleven strains reduced the pH. The levels of lactate, acetate, and formate in both the yogurt and milk were altered in a strain-specific manner. The results suggested that the metabolism by these strains differed significantly during the shelf-life. Careful strain selection is required to identify probiotic L. casei strains that will survive through shelf-life in either yogurt or fluid milk and not impact product quality. [ABSTRACT FROM AUTHOR]

Summary: Plant‐based probiotic beverages are gaining popularity among vegans, lactose intolerants, and those with milk‐protein allergies. Sorghum bicolor is a cereal rich in phytochemicals that can promote probiotic growth when malted. The packaging type may impact the characteristics and probiotic survival in plant‐based probiotic beverages. This study aimed to evaluate the impact of different packaging materials (polyethylene terephthalate (PET), high‐density polyethylene (HDPE), and glass) on quality parameters, probiotic survival (Lacticaseibacillus casei), and sensory acceptance of strawberry‐flavoured probiotic sorghum‐based beverages. The packaging type did not affect the product's chemical composition, quality parameters, antioxidant activity, or probiotic survival. However, the products stored in PET and HDPE packaging showed a lower consistency index, higher dissolved oxygen concentration, improved probiotic survival to simulated gastrointestinal conditions, and better sensory acceptance. Malted S. bicolor can be used to produce probiotic beverages with adequate probiotic survival and physicochemical parameters and reasonable sensory acceptance during 28 days of refrigerated storage. [ABSTRACT FROM AUTHOR]

A variety of foods fermented with lactic acid bacteria (LAB) serve as dietary staples in many countries. The incorporation of health-promoting probiotics into fermented milk products can have profound effects on human health. Considering the health benefits of Yakult, the current study was undertaken to develop an enriched Yakult-like fermented skimmed milk drink by the addition of two probiotic strains, namely Lacticaseibacillus casei (Lc) and Lacticaseibacillus rhamnosus (Lr). The prepared drinks were compared in terms of various parameters, including their physicochemical properties, proximate chemical composition, mineral estimation, microbial viable count, antioxidant activity, and sensory evaluation. Each strain was employed at five different concentrations, including 1% (T1), 1.5% (T2), 2% (T3), 2.5% (T4), and 3% (T5). The prepared Yakult samples were stored at 4 °C and analyzed on days 0, 7, 14, 21, and 28 to evaluate biochemical changes. The findings revealed that the concentration of the starter culture had a significant (p ≤ 0.05) impact on the pH value and moisture and protein contents, but had no marked impact on the fat or ash content of the developed product. With the Lc strain, Yakult's moisture content ranged from 84.25 ± 0.09 to 85.65 ± 0.13%, whereas with the Lr strain, it was from 84.24 ± 0.08 to 88.75 ± 0.13%. Protein levels reached their highest values with T5 (3% concentration). The acidity of all treatments increased significantly due to fermentation and, subsequently, pH showed a downward trend (p ≤ 0.05). The total soluble solids (TSS) content decreased during storage with Lc as compared to Lr, but the presence of carbohydrates had no appreciable impact. The drink with Lc exhibited a more uniform texture and smaller pore size than Yakult with Lr. Except for the iron values, which showed an increasing trend, the contents of other minerals decreased in increasing order of the added probiotic concentration used: 1% (T1), 1.5% (T2), 2% (T3), 2.5% (T4), and 3% (T5). The highest lactobacilli viable count of 8.69 ± 0.43 colony-forming units (CFU)/mL was observed with the T1 Lr-containing drink at the end of the storage period. Regarding the storage stability of the drink, the highest value for DPPH (88.75 ± 0.13%) was found with the T1 Lc drink on day 15, while the highest values for FRAP (4.86 ± 2.80 mmol Fe2+/L), TPC (5.97 ± 0.29 mg GAE/mL), and TFC (3.59 ± 0.17 mg GAE/mL) were found with the T5 Lr drink on day 28 of storage. However, the maximum value for ABTS (3.59 ± 0.17%) was noted with the T5 Lr drink on the first day of storage. The results of this study prove that Lc and Lr can be used in dairy-based fermented products and stored at refrigerated temperatures. [ABSTRACT FROM AUTHOR]

Dosidicus gigas is a kind of low-fat food with poor gel properties. Fermentation has been proved to be an effective food processing method that could improve the gel properties of meat. Here, we inoculated D. gigas with two strains, Lacticaseibacillus casei and Staphylococcus carnosus, that have been approved for use in meat processing, and studied their impact on the quality of the product. Compared with the uninoculated samples, inoculation with L. casei and mixed inoculation with L. casei and S. carnosus were able to significantly reduce pH during fermentation. The plate counting results showed that L. casei may have adapted well to the environment in the inoculated groups, while the growth of Staphylococcus may have been inhibited in the mixed inoculated group. 16s rRNA sequencing confirmed that inoculation significantly altered the bacterial composition of squid surimi sausages. Both inoculation with L. casei and mixed inoculation with L. casei and S. carnosus were able to inhibit the accumulation of the main biogenic amines, and in the mixed inoculated group, the main biogenic amines were lower. Compared with unfermented squid surimi sausages, mixed inoculation changed the texture, gel properties, color, and appearance of squid surimi sausages. These results showed that mixed inoculation can not only ensure safety, but also improve the quality of squid surimi sausages. [ABSTRACT FROM AUTHOR]

Abstract Probiotics are defined as live microbial food elements that are beneficial to human health. Lacticaseibacillus casei T1 was considered to have potential as a bioactive ingredient in functional foods, which was isolated from kurut. Previous research by our group proved that L. casei T1 could prevent inflammatory responses caused by Helicobacter pylori. This study aimed to investigate whether treatment with L. casei T1 resulted in a suppressive effect on H. pylori-induced oxidative stress and inflammatory responses. The results showed that treatment with L. casei T1 could relieve H. pylori-induced overexpression of inflammatory cytokines in GES-1 cells. Experiments in animals suggested that taking long-term L. casei T1 could reduce oxidative stress and inflammatory cytokines and improve H. pylori-induced gastric mucosal damage. Furthermore, taking L. casei T1 could increase the relative abundance of beneficial intestinal bacterium (Lachnospiraceae and Odoribacter) of H. pylori-infected mice and help in maintaining the balance of intestinal microflora. Collectively, L. casei T1 had certain degrees of therapeutic effect against H. pylori. In the future, it combined with antibiotics for H. pylori eradication deserves further study.

Copyright of Zywnosc is the property of Polish Society of Food Technologists - Scientific Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wound healing is a multi-factorial response to tissue injury, aiming to restore tissue continuity. Numerous recent experimental and clinical studies clearly indicate that probiotics are applied topically to promote the wound-healing process. However, the precise mechanism by which they contribute to healing is not yet clear. Each strain appears to exert a distinctive, even multi-factorial action on different phases of the healing process. Given that a multi-probiotic formula exerts better results than a single strain, the pharmaceutical industry has embarked on a race for the production of a formulation containing a combination of probiotics capable of playing a role in all the phases of the healing process. Hence, the object of this review is to describe what is known to date of the distinctive mechanisms of each of the most studied probiotic strains in order to further facilitate research toward the development of combinations of strains and doses, covering the whole spectrum of healing. Eleven probiotic species have been analyzed, the only criterion of inclusion being a minimum of two published research articles. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria produce a variety of antimicrobial peptides known as bacteriocins. Most bacteriocins are understood to kill sensitive bacteria through receptor-mediated disruptions. Here, we report on the identification of the Lactobacillus plantarum plantaricin EF (PlnEF) receptor. Spontaneous PlnEF-resistant mutants of the PlnEF-indicator strain L. plantarum NCIMB 700965 (LP965) were isolated and confirmed to maintain cellular ATP levels in the presence of PlnEF. Genome comparisons resulted in the identification of a single mutated gene annotated as the membrane-bound, magnesium/cobalt efflux protein CorC. All isolates contained a valine (V) at position 334 instead of a glycine (G) in a cysteine-β-synthase domain at the C-terminal region of CorC. In silico template-based modeling of this domain indicated that the mutation resides in a loop between two β-strands. The relationship between PlnEF, CorC, and metal homeostasis was supported by the finding that PlnEF-resistance was lost when PlnEF was applied together with high concentrations of Mg2+ , Co2+ , Zn2+ , or Cu2+ . Lastly, PlnEF sensitivity was increased upon heterologous expression of LP965 corC but not the G334V CorC mutant in the PlnEF-resistant strain Lactobacillus casei BL23. These results show that PlnEF kills sensitive bacteria by targeting CorC.

ß-Galactosidase (EC 3.2.1.23) hydrolyzes β-D-galactosidic linkages at the non-reducing end of substrates to produce β-D-galactose. Lacticaseibacillus casei is one of the most widely utilized probiotic species of lactobacilli. It possesses a putative β-galactosidase belonging to glycoside hydrolase family 35 (GH35). This enzyme is encoded by the gene included in the gene cluster for utilization of lacto-N-biose I (LNB; Galβ1-3GlcNAc) and galacto-N-biose (GNB; Galβ1-3GalNAc) via the phosphoenolpyruvate: sugar phosphotransferase system. The GH35 protein (GnbG) from L. casei BL23 is predicted to be 6-phospho-β-galactosidase (EC 3.2.1.85). However, its 6-phospho-β-galactosidase activity has not yet been examined, whereas its hydrolytic activity against LNB and GNB has been demonstrated. In this study, L. casei JCM1134 LBCZ_0230, homologous to GnbG, was characterized enzymatically and structurally. A recombinant LBCZ_0230, produced in Escherichia coli, exhibited high hydrolytic activity toward o-nitrophenyl β-D-galactopyranoside, p-nitrophenyl β-D-galactopyranoside, LNB, and GNB, but not toward o-nitrophenyl 6-phospho-β-D-galactopyranoside. Crystal structure analysis indicates that the structure of subsite -1 of LBCZ_0230 is very similar to that of Streptococcus pneumoniae β-galactosidase BgaC and not suitable for binding to 6-phospho-β-D-galactopyranoside. These biochemical and structural analyses indicate that LBCZ_0230 is a β-galactosidase. According to the prediction of LNB's binding mode, aromatic residues, Trp190, Trp240, Trp243, Phe244, and Tyr458, form hydrophobic interactions with N-acetyl-D-glucosamine residue of LNB at subsite +1. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lacticaseibacillus casei (L. casei) increased the Lactobacillus relative abundance and lactic acid content; • L. casei decreased some volatile compounds and fruity flavor intensity, compromising sensory acceptance; • L. casei + camu-camu pulp increased the bioaccessibility of phenolics and improved the volatile profile; • L. casei + camu-camu pulp improved the antidiabetic and antioxidant activities and sensory properties; • L. casei + camu-camu pulp increased the Lactobacillus and decreased the Acetobacter and Komagataeibacter abundances. This study aimed to evaluate the effect of adding Lacticaseibacillus casei as probiotic culture and/or camu-camu (Myrciaria dubia) pulp on the chemical profile, technological, functional, and sensory properties, phenolics concentration and bioaccessibility, and microbiota of kombucha. Adding L. casei decreased some volatile compounds and fruity flavor intensity and increased the Lactobacillus relative abundance (+35.73 %) and lactic acid content (from 1.26 to 1.54 g/L), decreasing flavor and overall impression acceptances. Adding camu-camu pulp resulted in more acidic products (pH of 2.75 vs 3.24), with a higher concentration of some phenolic compounds. The kombucha with L. casei and camu-camu pulp was characterized by a higher concentration of citric and acetic acids, ethanol, ascorbic acid, and most of the phenolic compounds and volatile compounds, higher bioaccessibility of phenolic compounds, increased consistency index, improved functional properties (inhibition of α-glucosidase and antioxidant activity), and better sensory properties. Furthermore, it showed an increased relative abundance of Lactobacillus (+15.11 %) and a decreased relative abundance of Acetobacter (−5.56 %) and Komagataeibacter (−9.12 %) compared to the conventional kombucha. L. casei survived the processing (> 7 log CFU/mL) and simulated gastrointestinal conditions (>5 log CFU/mL). In conclusion, the association of L. casei and camu-camu pulp resulted in potentially probiotic kombuchas with improved chemical profile, functional, technological, and sensory properties, phenolic compounds concentration and bioaccessibility, and bacterial microbial diversity. [ABSTRACT FROM AUTHOR]

The effect of selected autochthonous Lactic Acid Bacteria (LAB) against Listeria monocytogenes was evaluated in two elaborations of soft-ripened cheese performed under high and low relative humidity (RH) elaborations, to achieve aw ranging from 0.97 to 0.94 in ripened cheeses. Two selected autochthonous strains of Lacticaseibacillus casei 31 and 116 were used. In each elaboration, 8 batches were physicochemically and microbiologically evaluated throughout the ripening process. The aw and pH decreased during ripening to final values ranging from 0.944 to 0.972 aw and 5.0 to 5.3 pH, respectively. LAB was the only microbial group that increased throughout the ripening in high and low RH elaborations. In batches that were uninoculated with LAB strains, L. monocytogenes was either maintained at the initial inoculation level or showed a slight reduction by the end of the ripening process. However, in LAB-inoculated batches in the two elaborations, steady decreases of L. monocytogenes were observed throughout maturation. L. casei 31 alone or in combination with strain 116 provoked reductions of 2 to 4 log CFU/g in L. monocytogenes over 60 days of ripening, which could be enough as a strategy for biocontrol to deal with the usual contamination by L. monocytogenes during cheese processing.

ABSTRACT This study aimed to evaluate the protective function of probiotics against Shigella sonnei pathogenicity. For this purpose, 400 zebrafish were divided into four groups with two replications: (T1): receiving Lacticaseibacillus casei for 27 days, (T2): receiving L. casei for 27 days followed by 72 hr exposure to S. sonnei, (T3): receiving basal diet for 27 days followed by 72 hr exposure to S. sonnei, and control group (C): receiving basal diet without exposure to the pathogen. According to the results, feeding with L. casei for 27 days reduced the interleukin-8 (IL-8) expression significantly (P

Salmonella Typhimurium is a foodborne pathogen that causes gastrointestinal disease. This study aimed to screen probiotic strains to prevent S. Typhimurium infection and explore the corresponding mechanisms. Based on the excellent inhibitory effect, Lacticaseibacillus casei WLCA02 was selected and investigated for its potential protective mechanism against S. Typhimurium by different models, namely, the S. Typhimurium infection mice model, HT-29 epithelial cell model, and RAW264.7 macrophage model. Our results showed that supplementation of live and heat-killed WLCA02 could significantly reduce the Salmonella loads in mice, enhance the intestinal barrier via upregulating the expression of tight junction proteins (ZO-1 and Claudin-1) and the number of goblet cells, and alleviate the inflammation. Meanwhile, WLCA02 could reduce the internalization and mobility of S. Typhimurium, and activate the RAW264.7 macrophages and improve the inflammation caused by Salmonella. These results indicate that L. casei WLCA02 can potentially be developed as an antibacterial functional food.

Probiotics are defined as live microbial food elements that are beneficial to human health. Lacticaseibacillus casei T1 was considered to have potential as a bioactive ingredient in functional foods, which was isolated from kurut. Previous research by our group proved that L. casei T1 could prevent inflammatory responses caused by Helicobacter pylori. This study aimed to investigate whether treatment with L. casei T1 resulted in a suppressive effect on H. pylori-induced oxidative stress and inflammatory responses. The results showed that treatment with L. casei T1 could relieve H. pylori-induced overexpression of inflammatory cytokines in GES-1 cells. Experiments in animals suggested that taking long-term L. casei T1 could reduce oxidative stress and inflammatory cytokines and improve H. pylori-induced gastric mucosal damage. Furthermore, taking L. casei T1 could increase the relative abundance of beneficial intestinal bacterium (Lachnospiraceae and Odoribacter) of H. pylori-infected mice and help in maintaining the balance of intestinal microflora. Collectively, L. casei T1 had certain degrees of therapeutic effect against H. pylori. In the future, it combined with antibiotics for H. pylori eradication deserves further study. [ABSTRACT FROM AUTHOR]

This study investigates the isolation and characterization of the main lactic acid bacteria responsible for fermentation of Oggtt, a dried fermented buttermilk. Five isolates with Gram‐positive staining and negative catalase and oxidase activity were identified using phenotypic and genotypic methods, and their antagonistic, exopolysaccharides and organic acid production, proteolytic activity, and antioxidant capacity were assessed. The isolates are classified as Lacticaseibacillus paracasei Ogt_1, Lacticaseibacillus casei Ogt_2, Lacticaseibacillus paracasei Ogt_3, Lacticaseibacillus paracasei Ogt_4, and Lacticaseibacillus paracasei Ogt_5. All strains possessed high antagonistic activity against Proteus vulgaris, Staphylococcus aureus, and Escherichia coli. All strains produced high levels of lactic acid (11177.3–15404.9 μg/ml), tartaric acid (2197.8–4058.5 μg/ml), and exopolysaccharides(20.86–239.9 mg/L) and possessed high proteolytic and antioxidant activity at variable manners. Overall, this study indicates the isolation of important Lacticaseibacillus strains from Oggtt, which could be used as starter cultures for developing functional foods. [ABSTRACT FROM AUTHOR]

The investigation was aimed at assessing anti‐inflammatory and antioxidative activities along with the release of peptides with antioxidative properties during the fermentation of camel milk by Lacticaseibacillus casei (NK9). Reverse‐phase high‐performance liquid chromatography (RP‐HPLC) was used to separate the bioactive peptides of 3 and 10 kDa (permeates and retentates). Reverse‐phase liquid chromatography–mass spectrometry (RPLC/MS) was used to identify and characterise the pure bioactive peptides, and the effect of fermented camel milk on inflammation produced by lipopolysaccharide (LPS)/endotoxin in RAW 264.7 (Ralph and William's cell line) was also examined. Furthermore, docking revealed that peptides (LLNEK and IYTFPQPQSL) were predicted to inhibit myeloperoxidase (nMPO) activity by engaging with different residues in and around the human myeloperoxidase (hMPO) active site. [ABSTRACT FROM AUTHOR]

Summary: This study aimed to evaluate the effect of high‐intensity ultrasound (HIUS) application with different processing times (2.5, 5, 7.5 and 10 min) on the physicochemical, rheological and textural properties, antioxidant activity (AA) and probiotic survival in strawberry‐flavoured fermented probiotic strawberry drink during storage (7°C for 28 days). The application of HIUS resulted in products with lower fermentation times, higher organic acid stability during storage and improved texture (higher firmness and consistency) and functional properties (higher phenolic compounds content and/or AA). Using 2.5 min of processing time would be advisable due to the better probiotic survival to simulated gastrointestinal conditions (probiotic counts higher than 106 CFU mL−1), reduced fermentation times (reduction in 3 h), higher lactic acid content during storage and enhanced AA. The products showed a viable probiotic counts higher than 106 CFU mL−1 during the entire shelf life. HIUS may be considered as an adequate pre‐treatment in the development of probiotic fermented probiotic strawberry drink. [ABSTRACT FROM AUTHOR]

Previous research has demonstrated promising outcomes regarding the advantageous impact of probiotics in both cancer prevention and treatment. Nevertheless, the precise molecular mechanisms underpinning these effects remain elusive. Recent investigations have proposed a potential involvement of micro ribonucleic acids (miRNAs) in mediating the favorable influence of probiotics on cancerous cells. This study was designed to evaluate the effect of Lactobacillus casei condition medium on miR-21 relative expression in HT-29 colorectal cancer cells. Lactobacillus casei condition medium mixed with RPMI in different proportions (1:1, 1:3, and 1:7) and utilized to treat HT-29 cells for 24 and 48 h. Subsequently, percentage of early and late apoptotic cells were identified using a flow cytometry instrument. A real-time polymerase chain reaction was carried out to determine the relative expression of miR-21. Our findings revealed that L. casei condition medium induces apoptosis in a time- and dose-dependent manner in HT-29 cells. Furthermore, we found a significantly downregulated miR-21 after treatment with high doses of L. casei condition medium after 48 h. Overall, our results provide valuable insights into a potential mechanism through which L. casei condition medium mediates its apoptotic effect in colorectal cancer cells through downregulation of miR-21. However, further investigations are required to unravel its therapeutic, diagnostic, and treatment monitoring potential. [ABSTRACT FROM AUTHOR]

Osteoporosis, a significant bone disease predominantly affecting elderly and postmenopausal women, leads to increased bone fragility and fracture risk, presenting a major public health concern with substantial socioeconomic implications. This study investigated the therapeutic potential of Lactobacillus strains, known for their immunomodulatory properties, in an ovariectomy-induced osteoporosis mouse model. Among three tested strains Lactobacillus casei GKC1, Lactobacillus rhamnosus GKLC1, and Lactobacillus johnsonii GKJ2, GKC1 demonstrated superior efficacy in promoting osteogenesis-related gene expression, including alkaline phosphatase (ALP), bone morphogenetic protein 2 (BMP2) and runt-related transcription factor 2 (RUNX2). In ovariectomized mice (n = 8/group), both live and heat-inactivated GKC1 (57 mg/kg) and fermented GKC1 (1000 mg/kg) were administered orally for 28 days, with alendronate (2.5 mg/kg) serving as a positive control. The treatment significantly improved bone mineral density and femoral microstructure parameters compared to the ovariectomized control group. For the first time, heat-inactivated GKC1 exhibited superior anti-inflammatory effects through reduction of IL-17A and enhanced bone microstructural integrity, suggesting its potential as a safe and effective therapeutic agent for postmenopausal osteoporosis management. These findings provide compelling evidence for the development of postbiotic-based interventions in osteoporosis treatment, offering a promising alternative to conventional therapeutics., Competing Interests: Declaration of Competing interest Grape King Bio Ltd. provided salaries and research materials to Tsung-Ju Li, You-Shan Tsai, Ci-Sian Wang, Shih-Wei Lin, Yen-Lien Chen, and Chin-Chu Chen. The company had no other involvement in the research process. The remaining authors declare no conflicts of interest., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

This research delved into the feasibility of utilizing three nanochitin-chitin nanocrystal (CNC), chitin nanofiber (CNF), and chitin nanosphere (CNS) in complexation with whey protein isolate (WPI) to fabricate complex coacervation and create microcapsules for probiotic encapsulation. The results showed that CNC, CNF, and CNS exhibited notable differences in morphologies, dimensions, and properties due to the respective synthesis methodologies. Nevertheless, all of them maintained a positive charge and were capable of assembling into microcapsules with WPI via electrostatic interactions at optimal pHs. The inclusion of Lactobacillus casei (L. casei) during the complex coacervation phase engendered a shell-like formation around the bacterium within the microcapsule, which enhanced probiotic viability and increased colony-forming unit count. Additionally, these probiotic-loading microcapsules were also processed into tablets, displaying robust structural integrity, augmented protective capabilities, and a distinctive sustained-release profile compared to the microcapsules alone. In summary, this study pioneered the employment of nanochitin formulations in complex coacervation to encapsulate L. casei, spearheading an innovative approach to the creation of a compressed probiotic supplement and contributing to the advancement in the design and fabrication of encapsulation vehicles for active ingredients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Oleogels (organogels) are systems resembling a solid substance based on the gelation of organic solvents (oil or non-polar liquid) through components of low molecular weight or oil-soluble polymers. Such compounds are organogelators that produce a thermoreversible three-dimensional gel network that captures liquid organic solvents. Oleogels based on natural oils are attracting more attention due to their numerous advantages, such as their unsaturated fatty acid contents, ease of preparation, and safety of use. As a result of the research, two oleogels were developed, into which freeze-dried alginate carriers with a probiotic, L. casei , were incorporated. Two techniques were used to produce probiotic-loaded capsules-extrusion and emulsification. Alginate beads obtained by the extrusion process have a size of approximately 1.2 mm, while much smaller microspheres were obtained using the emulsification technique, ranging in size from 8 to 17 µm. The trehalose was added as a cryoprotectant to improve the survival rate of probiotics in freeze-dried alginate carriers. The encapsulation efficiency for both of the methods applied, the emulsification and the extrusion technique, was high, with levels of 90% and 87%, respectively. The obtained results showed that the production method of probiotic-loaded microspheres influence the bacterial viability. The better strain survival in the developed systems was achieved in the case of microspheres produced by the emulsification (reduction in bacterial cell viability in the range of 1.98-3.97 log in silica oleogel and 2.15-3.81 log in sucragel oleogel after 7 and 30 days of storage) than by the extrusion technique (after a week and a month of oleogel storage, the decrease in cell viability was 2.52-4.52 log in silica oleogel and 2.48-4.44 log in sucragel oleogel).

Lactobacillus casei Zhang (Lac.z), isolated from traditional sour horse milk in Inner Mongolia, can alleviate various diseases and promote health. Our previous studies found that pretreatment with live Lac.z (L-Lac.z) could significantly attenuate acute kidney injury and delay the progression of chronic renal fibrosis. However, it is unknown whether these effects could be maintained by pasteurized Lac.z (P-Lac.z). Mouse models of acute kidney injury and chronic renal fibrosis induced by renal bilateral ischemia-reperfusion (BIR) surgery were treated with L-Lac.z or P-Lac.z by gavage. Serum and kidney samples were collected to analyze the extent of renal injury and fibrosis, and proteomics was used to explore the potential mechanisms underlying the differences in the effects of the two forms of Lac.z. The results revealed that treatment with L-Lac.z led to a reduction in serum urea nitrogen levels and in less renal tubular injury and subsequent renal fibrosis after BIR-induced renal injury, whereas these effects were not observed in the P-Lac.z group. Proteomic analysis revealed 19 up-regulated proteins and 39 down-regulated proteins in the P-Lac.z group, and these gene products were associated with growth and stress resistance. The specific nephroprotective effects of L-Lac.z may be independent of the interaction of live probiotics with the host., Competing Interests: Declarations. Ethical approval: All authors have read the current manuscript. Consent for publication: All authors have approved the current manuscript for publication. Consent to participate: Not applicable. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s).)

Lacticaseibacillus casei N87 was used as starter culture for the production of fermented sausages. The strain was cultivated in anaerobic (A) and respiratory (growth in presence of oxygen and supplementation with haeme and menaquinone in the growth medium; R) conditions. Control without the starter culture inoculation and with the addition of 150 mg/kg of nitrate was also included. The effect on physico-chemical parameters (pH, Aw, weight loss, and color), microbial population, volatilome, proteolysis as well as the survival of the strain was evaluated during 90 days of ripening. Q-PCR and DGGE-PCR analyses demonstrated the ability of the strain used in this study to adapt to this environment and carry out the sausage's fermentation process. The inoculation of the strain did not have any effect on the Aw values, which decreased similarly in the different samples whereas the pH was lower in A samples (5.2) and the weight loss in R samples (2.5% less than the others). The color parameters of the samples inoculated with the starter cultures were comparable to those of the control added with nitrate. The concentration of aldehydes that usually are identified as marker of oxidation processes was similar in the samples inoculated with the starter cultures adapted under respiratory conditions and in the control. On the contrary, a higher level was detected in the samples inoculated with the starter cultivated under anaerobic conditions. The proteolysis that occurred during the ripening indicates the differentiation of the A samples from the others. Nonetheless, the volatile profiles of the inoculated fermented sausages were similar. The study demonstrated that aerobic adaptation of Lcb. casei N87 starter culture gave similar color parameters and amounts of aldehydes in sausages fermentations without nitrate compared to conventional fermentations with nitrate.

A variety of foods fermented with lactic acid bacteria (LAB) serve as dietary staples in many countries. The incorporation of health-promoting probiotics into fermented milk products can have profound effects on human health. Considering the health benefits of Yakult, the current study was undertaken to develop an enriched Yakult-like fermented skimmed milk drink by the addition of two probiotic strains, namely Lacticaseibacillus casei (Lc) and Lacticaseibacillus rhamnosus (Lr). The prepared drinks were compared in terms of various parameters, including their physicochemical properties, proximate chemical composition, mineral estimation, microbial viable count, antioxidant activity, and sensory evaluation. Each strain was employed at five different concentrations, including 1% (T1), 1.5% (T2), 2% (T3), 2.5% (T4), and 3% (T5). The prepared Yakult samples were stored at 4 °C and analyzed on days 0, 7, 14, 21, and 28 to evaluate biochemical changes. The findings revealed that the concentration of the starter culture had a significant (p ≤ 0.05) impact on the pH value and moisture and protein contents, but had no marked impact on the fat or ash content of the developed product. With the Lc strain, Yakult’s moisture content ranged from 84.25 ± 0.09 to 85.65 ± 0.13%, whereas with the Lr strain, it was from 84.24 ± 0.08 to 88.75 ± 0.13%. Protein levels reached their highest values with T5 (3% concentration). The acidity of all treatments increased significantly due to fermentation and, subsequently, pH showed a downward trend (p ≤ 0.05). The total soluble solids (TSS) content decreased during storage with Lc as compared to Lr, but the presence of carbohydrates had no appreciable impact. The drink with Lc exhibited a more uniform texture and smaller pore size than Yakult with Lr. Except for the iron values, which showed an increasing trend, the contents of other minerals decreased in increasing order of the added probiotic concentration used: 1% (T1), 1.5% (T2), 2% (T3), 2.5% (T4), and 3% (T5). The highest lactobacilli viable count of 8.69 ± 0.43 colony-forming units (CFU)/mL was observed with the T1 Lr-containing drink at the end of the storage period. Regarding the storage stability of the drink, the highest value for DPPH (88.75 ± 0.13%) was found with the T1 Lc drink on day 15, while the highest values for FRAP (4.86 ± 2.80 mmol Fe2+/L), TPC (5.97 ± 0.29 mg GAE/mL), and TFC (3.59 ± 0.17 mg GAE/mL) were found with the T5 Lr drink on day 28 of storage. However, the maximum value for ABTS (3.59 ± 0.17%) was noted with the T5 Lr drink on the first day of storage. The results of this study prove that Lc and Lr can be used in dairy-based fermented products and stored at refrigerated temperatures.

Lacticaseibacillus casei is used extensively in the fermented milk-beverage industry as a starter culture. Acid production capacity during fermentation is the main criterion for evaluating starters although it is strain-dependent. In this study, the acid production rates of 114 L. casei strains were determined and then classified into high acid (HC), medium acid (MC), and low acid (LC) groups. Comparative genomics analysis found that the lac operon genes encoding the phosphoenolpyruvate-lactose phosphotransferase system (PTSLac) were located on plasmids in the HC strains; however, it is notable that the corresponding operons were located on the chromosome in LC strains. Real-time PCR analysis showed that the copy numbers of lac operon genes in HC strains were between 3.1 and 9.3. To investigate the relationship between copy number and acid production rate, the lac operon cluster of the HC group was constitutively expressed in LC strains. The resulting copy numbers of lac operon genes were between 15.8 and 18.1; phospho-β-galactosidase activity increased by 1.68–1.99-fold; and the acid production rates increased by 1.24–1.40-fold, which enhanced the utilization rate of lactose from 17.5 to 42.6% in the recombinant strains. The markedly increased expression of lac operon genes increased lactose catabolism and thereby increased the acid production rate of L. casei. [ABSTRACT FROM AUTHOR]

Background: Intestinal mucositis is one of the most common and important side effects of 5-fluorouracil (5-FU). Currently, there are still no specific and effective protocols for its prevention and treatment. The aim of the present study was to evaluate the effect of oral administration of Lacticaseibacillus casei (L. casei) on the progression of 5-FU-induced intestinal mucositis. Methods: L. casei (1x109 CFU/ml) or saline was orally administered to Swiss mice, beginning 15 days before intestinal mucositis induction by single intraperitoneal 5-FU administration (450 mg/kg). Body weight, number of peripheral leukocytes and fecal lactic acid bacteria were monitored. After euthanasia, on day 18, tissue samples from colon and each small intestine segment were collected for histopathology. Jejunal tissues were collected and evaluated for iNOS and TNF-alpha immunoexpression, IL-1-beta, IL-6 and TNF-alpha levels, malonaldehyde (MDA) accumulation, invertase activity and factor nuclear kappa B (NFkB-P65) gene expression, toll like receptor-4 (TLR-4), mucin-2 (MUC-2), occludin and zonula occludens-1 (ZO-1). Results: The positive impact of L. casei on 5-FU-induced leukopenia was observed, but not on 5-FU-induced weight loss in mice. L. casei reduced 5-FU-induced inflammation in the colon and small intestine (p<0.05). Decreased TNF-α, IL-1β, IL-6 (p<0.05) and MDA (p<0.05) levels, as well as decreased iNOS and TNF-alpha protein expressions (p<0.05) were found in the jejunum from L casei group. In addition, L-casei down-regulated NFKB-P65 (p<0.05) and TLR-4 (p<0.05) gene expressions and up-regulated MUC-2 and mucosal barrier proteins occludin and ZO-1 gene expressions (p<0.05). Furthermore, greater lactic acid bacteria population (p<0.05) was found in the L. casei group when compared to control groups. Conclusion: Oral L. casei administration can protect the intestine of Swiss mice from 5-FU-induced intestinal mucositis, thus contributing to overall health. [ABSTRACT FROM AUTHOR]

An in silico study that featured the effect of starter cultures on the bioactivity and other health benefits of peptides in semi-hard cheese is presented in this contribution. Model Caciotta-type cheese samples were obtained in laboratory conditions in two variations. Sample A included starter cultures of Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris. Sample B included starter cultures of Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, and a culture of lactobacilli Lacticaseibacillus casei. The in silico method showed that the peptides inhibited angiotensin-converting enzymes (ACE) and ipeptidyl peptidase IV (DPP-4), as well as possessed antioxidant properties. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris had a greater effect on the formation of bioactive peptides. [ABSTRACT FROM AUTHOR]