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Lactobacillus species are widely recognized for their probiotic potential, focusing on their mechanisms of health benefits and protection. Here we conducted an in vitro investigation of the probiotic potential with a role in microbiome homeostasis of four strains: Lactiplantibacillus plantarum L6 and F53, Ligilactobacillus salivarius 1, and Lactobacillus helveticus 611. A broad spectrum of antibacterial and antifungal activity was determined. The strain-specific inhibition of Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, and saprophytic/toxigenic fungi makes them promising as protective cultures. DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) measurements showed that tested samples had strain-specific capacity for scavenging of radicals. The molecular base for the antioxidant potential of two lyophilized forms of active strains was investigated by electron paramagnetic resonance spectroscopy. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, with fractions of the most active postbiotics obtained by SEC-FPLC (fast protein liquid chromatography) analysis, showed a wide variety of effects on the growth of a K562 myeloid leukemia cell line. The IC50 (half-maximal inhibitory concentration) of L. salivarius 1 was determined to be 46.15 mg/mL. The proven in vitro functionality of the selected lactobacilli make them suitable for development of target probiotics with specific beneficial effects expected in vivo. Further investigations on produced postbiotics and safety have to be completed before they can be considered as scientifically proven probiotic strains. [ABSTRACT FROM AUTHOR]

Recently, there has been an increasing interest in the association of gut microbiota with health conditions and the potentially beneficial role of several types of biotics in several population groups, including children and adolescents. Children and adolescents comprise a unique population group due their rapid growth rates, high nutritional requirements, the immaturity of their immune system in early life, and their susceptibility to infectious diseases. The aim of the present study is to investigate the role and limitations of the administration of biotics in specific conditions affecting children and adolescents. A narrative review of related articles published on PubMed up to October 2023 was conducted. The administration of biotics has been evaluated in several health conditions among children and adolescents, such as the treatment and prevention of infectious diarrhea, the prevention of diarrhea after the use of antibiotics, the prevention of necrotizing enterocolitis, the treatment of functional gastrointestinal diseases, such as infant colic, functional abdominal pain, and irritable bowel syndrome, the eradication of H. pylori, the treatment of ulcerative colitis and pouchitis, and the prevention of atopic dermatitis, and the findings indicate improved symptoms and various beneficial health outcomes. However, some limitations have been identified regarding probiotics' use. In conclusion, biotics may have a beneficial impact in several health conditions among children and adolescents. There is a need for additional randomized, controlled clinical studies on the effects of the administration of biotics in children and particularly in adolescents and young adults. [ABSTRACT FROM AUTHOR]

Lactobacillus species are widely recognized for their probiotic potential, focusing on their mechanisms of health benefits and protection. Here we conducted an in vitro investigation of the probiotic potential with a role in microbiome homeostasis of four strains: Lactiplantibacillus plantarum L6 and F53, Ligilactobacillus salivarius 1, and Lactobacillus helveticus 611. A broad spectrum of antibacterial and antifungal activity was determined. The strain-specific inhibition of Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, and saprophytic/toxigenic fungi makes them promising as protective cultures. DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) measurements showed that tested samples had strain-specific capacity for scavenging of radicals. The molecular base for the antioxidant potential of two lyophilized forms of active strains was investigated by electron paramagnetic resonance spectroscopy. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, with fractions of the most active postbiotics obtained by SEC-FPLC (fast protein liquid chromatography) analysis, showed a wide variety of effects on the growth of a K562 myeloid leukemia cell line. The IC50 (half-maximal inhibitory concentration) of L. salivarius 1 was determined to be 46.15 mg/mL. The proven in vitro functionality of the selected lactobacilli make them suitable for development of target probiotics with specific beneficial effects expected in vivo. Further investigations on produced postbiotics and safety have to be completed before they can be considered as scientifically proven probiotic strains.

IntroductionAccording to WHO, antibiotic resistance is increasing to hazardous levels worldwide. Candidiasis often occurs after taking antibiotics. Therefore, antibiotic resistance is a global problem and searching for antibacterial agents is necessary.AimTo determine the antimicrobial activity of bacterial lysate of Lactobacillus (L.) rhamnosus DV separately and with plant extracts against bacterial and yeast test cultures.Material and methodsAntimicrobial activity of Del-Immune V® (cell wall and DNA fragments from a L. rhamnosus DV) separately and with cinnamon, beetroot, and blackcurrant extracts was determined by the minimum inhibitory concentration (MIC). Twofold serial dilutions determined the MIC in previously prepared meat-peptone broth (MPB) for bacteria and liquid wort for yeast. In the study, gram-negative (Escherichia coli IEM-1, Proteus vulgaris PА-12, Pseudomonas sp. MI-2, L. rhamnosus 13/2) and gram-positive (Bacillus (B.) subtilis BТ-2, Staphylococcus aureus BМС-1) bacteria, as well as yeast (Candida (C.) albicans D-6, C. tropicalis PE-2, C. utilis BVS-65) were used as test cultures.ResultsThe MIC for the studied bacterial test cultures after application of L. rhamnosus DV bacterial lysates was from 1.0 ± 0.05 mg/mL to 12.5 ± 0.63 mg/mL, which was significantly less than that of the thermally inactivated control (MIC from 125.0 ± 6.25 mg/mL to 250.0 ± 12.5 mg/mL). B. subtilis BT-2 culture was the least sensitive to the action of the bacterial lysate (MIC—12.5 ± 0.63 mg/mL). It showed the best antibacterial and antifungal effect bacterial lysate with the phytonutrient blackcurrant.ConclusionsIt was demonstrated that bacterial lysate of lactic acid bacteria L. rhamnosus DV exhibits antibacterial and antifungal properties during direct contact with pathogenic agents.

Recently, there has been an increasing interest in the association of gut microbiota with health conditions and the potentially beneficial role of several types of biotics in several population groups, including children and adolescents. Children and adolescents comprise a unique population group due their rapid growth rates, high nutritional requirements, the immaturity of their immune system in early life, and their susceptibility to infectious diseases. The aim of the present study is to investigate the role and limitations of the administration of biotics in specific conditions affecting children and adolescents. A narrative review of related articles published on PubMed up to October 2023 was conducted. The administration of biotics has been evaluated in several health conditions among children and adolescents, such as the treatment and prevention of infectious diarrhea, the prevention of diarrhea after the use of antibiotics, the prevention of necrotizing enterocolitis, the treatment of functional gastrointestinal diseases, such as infant colic, functional abdominal pain, and irritable bowel syndrome, the eradication of H. pylori, the treatment of ulcerative colitis and pouchitis, and the prevention of atopic dermatitis, and the findings indicate improved symptoms and various beneficial health outcomes. However, some limitations have been identified regarding probiotics’ use. In conclusion, biotics may have a beneficial impact in several health conditions among children and adolescents. There is a need for additional randomized, controlled clinical studies on the effects of the administration of biotics in children and particularly in adolescents and young adults.

Hylak® forte is a postbiotic that inhibits the growth of pathogenic bacteria by reducing intestinal pH. It is assumed the potential presence of short-chain fatty acids (SCFAs) in Hylak® forte may contribute to this effect. In this current study, we analysed the composition of Hylak® forte, using a validated gas chromatography assay test method, to ascertain whether SCFAs are present in this postbiotic treatment. Hylak® forte was screened for C1 to C10 SCFAs by a gas chromatographic assay. In this assay, SCFAs were analysed as for their volatile ethyl ester derivatives in a 3.0 mL Hylak® forte sample. An additional screening procedure was conducted for the presence of vitamins and simple sugars. The gas chromatographic method for determining SCFAs was validated according to the requirements of ICH guideline Q2 (R1). Formic and acetic acids were identified in Hylak® forte at 27.92 ppm (90% confidence interval (CI), 26.90–28.94) and 306.17 ppm (90% CI, 277.11–335.22), respectively. Additional compounds were quantified in the solution, including vitamin B1 (0.029 mg/100 g), monosaccharides and disaccharides (2.767 g/100 g), as well as glutamic acid and glutamine (0.047 g/100 g). This study has identified formic acid in a range of 39.33 (90% CI, 36.50–42.17)–48.33 (90% CI, 45.91–50.76) ppm and acetic acid dropping down to 312.33 (90% CI, 295.32–329.35) from initial 415.67 ppm (90% CI, 385.93–445.41) in commercial Hylak® forte samples under forced degradation conditions. In addition, a range of other compounds in Hylak® forte was identified, including riboflavin and glutamine. Further studies are necessary to establish whether these compounds translate into tangible therapeutic effects. [ABSTRACT FROM AUTHOR]

Wild probiotic consortia of microorganisms (bacteria and yeasts) associated in the artisanal cultures' microbiota (milk kefir grains, water kefir grains and kombucha) are considered valuable promoters for metabiotics (prebiotics, probiotics, postbiotics and paraprobiotics) production. The beneficial effects of the fermented products obtained with the artisanal cultures on human well-being are described by centuries and the interest for them is continuously increasing. The wild origin and microbial diversity of these above-mentioned consortia give them extraordinary protection capacity against microbiological contaminants in unusual physico-chemical conditions and unique fermentative behaviour. This review summarizes the state of the art for the wild artisanal cultures (milk and water kefir grains, respectively, kombucha—SCOBY), their symbiotic functionality, and the ability to ferment unconventional substrates in order to obtain valuable bioactive compounds with in vitro and in vivo beneficial functional properties. Due to the necessity of the bioactives production and their use as metabiotics in the modern consumer's life, artisanal cultures are the perfect sources able to biosynthesize complex functional metabolites (bioactive peptides, antimicrobials, polysaccharides, enzymes, vitamins, cell wall components). Depending on the purposes of the biotechnological fermentation processes, artisanal cultures can be used as starters on different substrates. Current studies show that the microbial synergy between bacteria—yeast and/or bacteria—offers new perspectives to develop functional products (food, feeds, and ingredients) with a great impact on life quality. [ABSTRACT FROM AUTHOR]