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The underlying mechanisms of probiotics and postbiotics are not well understood, but it is known that both affect the adaptive and innate immune responses. In addition, there is a growing concept that some probiotic strains have common core mechanisms that provide certain health benefits. Here, we aimed to elucidate the signalization of the probiotic bacterial strains Lactobacillus paragasseri K7, Limosilactobacillus fermentum L930BB, Bifidobacterium animalis subsp. animalis IM386 and Lactiplantibacillus plantarum WCFS1. We showed in in vitro experiments that the tested probiotics exhibit common TLR2‐ and TLR10‐dependent downstream signalling cascades involving inhibition of NF‐κB signal transduction. Under inflammatory conditions, the probiotics activated phosphatidylinositol 3‐kinase (PI3K)/Akt anti‐apoptotic pathways and protein kinase C (PKC)‐dependent pathways, which led to regulation of the actin cytoskeleton and tight junctions. These pathways contribute to the regeneration of the intestinal epithelium and modulation of the mucosal immune system, which, together with the inhibition of canonical TLR signalling, promote general immune tolerance. With this study we identified shared probiotic mechanisms and were the first to pinpoint the role of anti‐inflammatory probiotic signalling through TLR10.

Lactic acid bacteria and bifidobacteria deliberately introduced into the food chain may act as a reservoir of antimicrobial resistance genes (ARGs), which is considered a safety concern. In the present study, resistance to antimicrobials of commercial probiotic strains, probiotic candidate strains, and starter cultures (n = 20) was characterised based on integration of phenotypic and in silico data. Minimum inhibitory concentrations (MICs) of 16 antimicrobials were determined for lactobacilli and bifidobacteria that were isolated from pharmaceutical products or obtained from the manufacturers or culture collections. Using different databases and bioinformatic tools, we predicted ARGs, mutations, genomic islands, and mobile genetic elements (MGEs) in their whole genome sequences. In addition, a comprehensive in silico analysis of the prevalence of the tetW gene and its genetic environment across lactobacilli and bifidobacteria (n = 1423) was conducted. Several strains exhibited phenotypic resistance to kanamycin, tetracycline, chloramphenicol, quinupristin-dalfopristin, ciprofloxacin, or neomycin. These resistances, however, did not always correspond to the presence of ARGs and vice versa. We detected an acquired tetW gene in four commercial strains of Bifidobacterium animalis subsp. lactis, whereas homologs of antimicrobial resistance (AR) proteins were predicted in all 20 proteomes. The prevalence of the tetW gene, which was often flanked by MGEs, was higher in analysed bifidobacteria (31.9%) than lactobacilli (6.3%). In addition, sequences flanking tetW were associated with putative genomic islands and were conserved in several strains, including potential pathogens. Our findings provide an insight into AR of probiotics, probiotic candidates, and starter cultures with an emphasis on tetracycline and into the safety of these strains in the context of AR.

Kadmijum je široko prisutni toksikant životne sredine, koji izaziva različite poremećaje u biološkim sistemima, uklјučujući tu i bubrežnu disfunkciju i degeneraciju tkiva jetre. Sa druge strane, pretpostavlјa se da su pozitivne osobine probiotskih bakterija u vezi sa njihovom sposobnošću da vezuju različite ligande, što dovodi do pobolјšanja crevne mikrobijalne ravnoteže i drugih koristi za domaćina. Imajući u vidu pomenuta, ova studija je sprovedena da istraži zaštitni efekat probiotika protiv kadmijum-indukovanog toksičnosti kod pacova. Muški pacovi Rattus norvegicus Wistar soja, težine 130±10 g, gajeni su u standardnim laboratorijskim uslovima (22±2°C, režim 12h svetlo/12h mrak) u metaboličkim kavezima (3 pacova/kavezu). Životinje su podeljene u četiri grupe: 1) kontrolne jedinke; 2) životinje tretirane probioticima; 3) životinje koje su primale kadmijum u formi CdCl2; i 4) životinje tretirane probioticima i kadmijumom. U krvi je određivana koncentracija kadmijuma, aktivnost alanin aminotransferaze (ALT) i aspartat aminotransferaze (AST), kao i nivoi adrenalina i noradrenalina. U homogenatima tkiva jetre i bubrega određivane su koncentracije kadmijuma, cinka i bakra, kao i aktivnosti ukupne superoksid dismutaze (SOD) i katalaze (CAT). Takođe, ispitivan je i histomorfološki profil tkiva jetre i bubrega u svim grupama životinja. U fecesu eksperimentalnih životinja određivana je koncentracija kadmijuma i mikrobijalni profil odabranih vrsta bakterija crevne mikroflore. Na kraju, Comet testom je testirana genotoksičnost kadmijuma in vitro and in vivo. Na osnovu naših rezultata mogu se izvesti sledeći zaključci:Davanje kadmijuma eksperimentalnim životinjama u formi kadmijum hlorida i koncentraciji 70ppm u pijaćoj vodi izaziva značajno smanjenje u porastu telesne mase tokom 5 nedelja eksperimenta... Cadmium is a ubiquitous environmental toxicant that causes a variety of disturbances in biological systems, including renal dysfunction and liver tissue degeneration. On the other hand, it is supposed that beneficial properties of probiotic bacteria are related to their capacity to adhere or bind different targets, thus leading to improved intestinal microbial balance and other benefits to host. Bearing aforementioned in mind, the present study was undertaken to investigate the protective effect of probiotic supplementation against cadmium-induced toxicity in rat. Male Wistar rats Rattus norvegicus, weighing 130±10 g, were acclimated to 22±2°C in metabolic cages (3 rats/cage) and maintained under a 12h light/12h dark cycle. Animals were divided into four groups: 1) controls; 2) probiotics treated; 3) CdCl2 treated; and 4) probiotics + CdCl2 treated. The cadmium concentrations were obtained in the blood, liver, kidney, and feces, as well as the blood alanine aminotransferase (ALT), aspartate aminotransferase (AST), adrenaline and noradrenaline activities. Furthermore, histomorphological changes of liver and kidney were determined, as well as the level of total supeoxide dismutase (SOD) and catalase (CAT) activities, and zinc and cooper concentration. Finally, cadmium genotoxicity were determined both in vitro and in vivo by Comet test, as well as the alterations in the fecal microflora content. Based on our results we can conclude that:1. Exposure of rats to cadmium chloride (70ppm) alone resulted in significant decrease in body weight gain compared with the control group...

Radi sve veće popularizacije proizvoda prirodnog podrijetla, osobito u području prehrane i prehrambenih aditiva, u posljednje je vrijeme intenzivirana uporaba sporo apsorbirajućih i neapsorbirajućih šećera kao supstrata za bakterije mliječne kiseline i kao prebiotika za ljudsku prehranu. Ljudsko debelo crijevo sadrži veliku koncentraciju bakterija (10000000000000 po gramu suhe tvari sadržaja debelog crijeva), a noviji radovi pokazuju da bifidobakterije i laktobacili, najbrojnije uobičajene anaerobne bakterije u mikroflori ljudskog debelog crijeva, korisno djeluju na zdravlje domaćina. Glavni čimbenik za razmnožavanje bifidobakterija u ljudskom probavnom sustavu je dijetalni šećer, pa korištenje neprobavljivih oligosaharida - kao što su rafinoza, fruktooligosaharidi, galaktozillaktoza, izomaltooligosaharidi ili transgalaktozilo-ligosaharidi - uzrokuju porast broja endogenih bifidobakterija i neke promjene kod bakterija mliječne kiseline. U radu su prikazani pregledi prebiotika i njihovih osobina kao i kriteriji za selekciju te sigurnost prebiotika i supstrata., There is an increasing consumer demand for natural products, particularly in the area of food or food additives. This has created some possibilities for the use of slowly absorbable and nonabsorbable sugars as substrates for lactic acid bacteria and as prebiotics for human nutrition. The human colon contains a high concentration of bacteria (10000000000000 per gram dry weight of colonic contents). Recent studies show that bifidobacteria and lactobacilli are among the common anaerobic bacteria in the human colonic microflora and may exert beneficial effects on the host. Dietary sugar source is the main factor affecting the multiplication of bifidobacteria in the human intestine. Consequently, the administration of nondigestible oligosaccharides such as raffinose, fructooligosaccharides, galactosyllactose, isomaltooligosaccharides, or transgalactosyloligosaccharied causes an increase in the number of endogenous bifidobacteria and some changes in lactic acid bacteria. In this paper prebiotics and theirs charasteristis were described as also criteria for selection and safety of prebiotics and substrates.