Explore the vast range of titles available.

In a screening for proteolytically active lactic acid bacteria, three strains, Lactobacillus delbrueckii ssp. lactis 92202, Lactobacillus helveticus 92201, and Lactobacillus delbrueckii ssp. bulgaricus 92059, showed the highest activities following growth in milk. All three strains degraded α- and β-casein, but did not hydrolyse κ-casein. HPLC analysis of skim milk fermentation revealed increasing amounts of peptides after 5 and 10 h with Lb. d. ssp. bulgaricus 92059. Hydrolysates obtained with Lb. d. ssp. lactis 92202 and Lb. d. ssp. bulgaricus 92059 revealed the highest angiotensin-converting enzyme-inhibitory effect. The effect was dose dependent. Almost no effect (<10%) was seen for Lb. helveticus 92201. For Lb. d. ssp. bulgaricus 92059, maximal inhibition of approx. 65% was reached after 25 h of fermentation. In an in vitro assay measuring potential immunomodulation, hydrolysates of the three strains yielded anti-inflammatory activities in the presence of TNF-α. However, the effects were more pronounced at lower hydrolysate concentrations. In the absence of TNF-α, slight pro-inflammatory effects were observed. The hydrolysate of Lb. d. ssp. bulgaricus 92059, when purified by means of solid-phase extraction, exhibited pro-inflammatory activity. Sour whey containing Lb. d. ssp. bulgaricus 92059 cells showed pro-inflammatory activity while cell-free sour whey was clearly anti-inflammatory. In the purified hydrolysate, 20 different α- and β-casein (CN)-derived peptides could be identified by LC-MS. Most peptides originated from the central and C-terminal regions of β-casein. Peptide length was between 9 (β-CN(f 59–67)) and 22 amino acids (β-CN(f 117–138)).

The abilities of certain microorganisms to be transferred across the food production chain, persist in the final product and, potentially, colonize the human gut are poorly understood. Here, we provide strain-level evidence supporting that dairy cattle-associated bacteria can be transferred to the human gut via consumption of Parmesan cheese. We characterize the microbial communities in samples taken from five different locations across the Parmesan cheese production chain, confirming that the final product contains microorganisms derived from cattle gut, milk, and the nearby environment. In addition, we carry out a human pilot study showing that Bifidobacterium mongoliense strains from cheese can transiently colonize the human gut, a process that can be enhanced by cow milk consumption. Some microorganisms may be transferred across the food production chain and, potentially, colonize the human gut. Here, Milani et al. provide strain-level evidence supporting that dairy cattle-associated bacteria can be transferred to the human gut via consumption of Parmesan cheese.

Despite goat milk having health benefits over cow milk, goat milk yogurt (GY) presents low consistency and viscosity, which reduces its overall acceptability by the consumer. Thus, new innovative methods can be an alternative to improve the quality of GY. Hence, this study aimed to investigate the effect of ultrasound (US) treatment with different sonication times on quality parameters of probiotic GY during refrigerated storage. US treatment was conducted at 20 KHz for 3, 6, and 9 min in yogurt. Lactobacillus bulgaricus and Lactobacillus acidophilus LA-5 were sensitive to US treatment, presenting a decrease in the yogurts stocked. This loss of viability led to reduced post-acidification due to smaller lactose metabolization in yogurt samples submitted to the US. Among tested treatments, the application of 6 min enhanced the apparent viscosity and consistency index of GY yogurts. In addition, this time also reduced tyramine and total biogenic amine (BAs) content. These findings suggest that 6 min of sonication is a promising way to improve the rheological properties and reduce the acidity and BAs content in GY. Further studies should be performed to optimize the US setting conditions to preserve the probiotic culture viability in yogurts.

Abstract The global population increase necessitates the dire need for ample food as medicine. Good health and well-being are stressed on probiotic functional foods. The present study characterizes biochemical and molecular identification of potential lactic acid bacteria. The potent antimicrobial properties also affirm Lactobacillus delbrueckii subsp. bulgaricus strain 3286. Biochemical analysis comprises carbohydrate fermentation, tolerance to acids and bile salts, production of bioactive compounds, lecithinase production, gelatinase production, and strain ripening ability. Antibiotic sensitivity to various antibiotics was assessed employing minimum inhibitory concentration (MIC) and E-test. Strain resistance to increased salt concentrations coherently concludes the positive impact of gut microbiome and gut-brain axis health management. The preliminary assessment requires further in vitro, in vivo, and in silico analysis for commercialization, market strategy and utility as functional food supplementation. The study can be rationalized for sustainable development goals regarding SDG 3: good health and well-being. Further, the UNSDG agenda 2030 also ascertains the role of probiotic foods in life longevity and public health management systems. Resumo O aumento da população global torna urgente a necessidade de alimentos abundantes como remédios. Alimentos funcionais probióticos são enfatizados para boa saúde e bem-estar. O presente estudo caracteriza a identificação bioquímica e molecular de potenciais bactérias lácticas. As potentes propriedades antimicrobianas também confirmam a cepa Lactobacillus delbrueckii subsp. bulgaricus 3286. A análise bioquímica compreende fermentação de carboidratos, tolerância a ácidos e sais biliares, produção de compostos bioativos, produção de lecitinase, produção de gelatinase e capacidade de amadurecimento da cepa. A sensibilidade aos antibióticos foi avaliada empregando concentração inibitória mínima (MIC) e teste E. A resistência da cepa a concentrações aumentadas de sal conclui coerentemente o impacto positivo do microbioma intestinal e do gerenciamento da saúde do eixo cérebro-intestino. A avaliação preliminar requer mais análises in vitro, in vivo e in silico para comercialização, estratégia de mercado e utilidade como suplementação alimentar funcional. O estudo pode ser racionalizado para objetivos de desenvolvimento sustentável em relação ao ODS 3: boa saúde e bem-estar. Além disso, a agenda UNSDG 2030 também verifica o papel dos alimentos probióticos na longevidade da vida e nos sistemas de gestão da saúde pública.

Objective Probiotic bacteria can inhibit the growth of harmful bacterial species but may be limited in the bacteria they can counteract. We developed a novel co-culture assay in which candidate probiotic bacteria can be co-incubated with both Gram-positive and Gram-negative reporter pathogens that have been modified to emit light, so as to monitor pathogen growth simply by quantitation of emitted light from the culture. We used this assay to identify a novel probiotic bacterium with anti-microbial activity against both Gram-positive and Gram-negative pathogens. Results We isolated a novel bacterium from non-pasteurized milk and identified it as a strain of Lactobacillus delbrueckii . Testing in our assay confirmed that this bacterium was able to inhibit the growth of both Staphylococcus aureus and Escherichia coli , but in a delayed fashion, after allowing a period of early growth. This activity was not dependent on living cells but also a property of conditioned medium. We posited that this was because the pathogens stimulated the production of an inhibitory factor from the Lactobacillus , presumably a bacteriocin peptide. Pre-treatment of conditioned medium with a protease abolished this inhibitory activity, indicating that L. delbrueckii is stimulated to produce an antibacterial peptide in the presence of a bacterial pathogen.

Rotavirus is a major cause of pediatric gastroenteritis, for which effective treatments are limited. This study investigates the antioxidant and antiviral potential of lactoferrin, Geobacillus stearothermophilus, and Lactobacillus delbrueckii subsp. lactis against Rotavirus infection. In this study, Geobacillus stearothermophilus and Lactobacillus delbrueckii subsp. lactis were isolated from Hammam Pharon soil and milk cheese, respectively, and identified using molecular techniques with accession numbers PP758390 and PP758383. The antioxidant effect against DPPH showed that lactoferrin exhibited the strongest scavenging ability, followed by Geobacillus stearothermophilus and Lactobacillus delbrueckii subsp. lactis. In vivo experiments involved administering lactoferrin, Geobacillus stearothermophilus, and Lactobacillus delbrueckii subsp. lactis in the drinking water of young mice for three days, followed by Rotavirus infection on the fourth day and sacrifice on the fifth day. The results demonstrated that lactoferrin significantly reduced the pathogenic effects of Rotavirus, as indicated by the normalization of inflammatory cytokines (TNF-α and IL-6) in the serum (p ≤ 0.001). Histological examination of small intestinal sections from Rotavirus-infected mice revealed extensive destruction of villus structures, while mice treated with lactoferrin showed no pathological changes compared to the control group. Geobacillus stearothermophilus-treated mice exhibited less pathological alteration and Lactobacillus delbrueckii subsp. lactis-treated mice showed mild pathological changes. Additionally, molecular docking studies indicated that bacteriocin (a bacterial protein) exhibited the highest binding affinity for the Rotavirus outer membrane protein (VP6) at -261.92 kcal/mol, outperforming lactoferrin (-229.32 kcal/mol). Additionally, bacteriocin's active compounds, turimicin (-7.9 kcal/mol) and lactin (-6.5 kcal/mol), also showed strong binding to VP6, suggesting their potential as therapeutic agents against Rotavirus. In conclusion, this study highlights the significant antiviral potential of lactoferrin against Rotavirus, demonstrating its ability to mitigate pathological changes and normalize inflammatory responses in infected mice. The findings also suggest that bacteriocins, particularly those with high binding affinities to Rotavirus proteins, could serve as promising candidates for therapeutic interventions against Rotavirus infections.

The volatile components of milks fermented using traditional starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) and probiotics (Lactobacillus lactis, Lactobacillus bifidus, Lactobacillus casei, and Lactobacillus plantarum) were investigated by means of gas chromatography-mass spectrometry (GC-MS) combined with simultaneous distillation extraction (SDE). A total of 53 volatile compounds were detected, being 10 aldehydes, 11 ketones, 10 acids, 11 hydrocarbons, 7 benzene derivatives, and 4 other compounds. The starter culture was found to significantly affect the composition of volatile components in the fermented milks. Ketones and hydrocarbons were the dominant compounds in milk before fermentation, while acids were dominant compounds in the fermented samples. Compared with probiotics, there was greater abundance of volatile components in fermented milks with traditional strains. The importance of each volatile compound was assessed on the basis of odor, thresholds, and odor activity values (OAVs). Of the volatile compounds, 31 of them were found to be odor-active compounds (OAV > 1). The component with the highest OAVs in most samples was (E,E)-2,4-decadienal. Heatmap analysis and principal component analysis were employed to characterize the volatile profiles of milks fermented by different starter cultures. The results could help to better understand the influence of starter cultures on the odor quality of milks.

Probiotics are living microorganisms that, when given in an adequate dose, have a healthy impact on human well-being. With global interest in self-care, dietary supplements especially probiotics is expanding rapidly due to their supported health effects. In this study, a total of twenty-two samples were collected from dairy products in Egypt’s markets, firstly isolated then identified and screened for probiotic properties under stressful conditions as NaCl, acid and bile salt conditions. After evaluation of the antimicrobial effect against widespread gram negative and gram positive human infecting bacteria, besides the antiviral assessment against ( SARS-CoV-2 ) virus which has disturbed the world, the antibiotic susceptibility test was done. Only three promising isolates were subjected for whole genome sequence with high-output next generation technology and the obtained data was subjected to a full bioinformatics analysis. The results obtained stated the advance of our isolates to tolerate the stress factors that can struggle in the human gut as well as the antimicrobial effects. All these bright characteristics were confirmed and illustrated in detail through different and reliable genome analysis tools. Our isolates were founded to have stable genome through containing mobile genetic elements like phages and CRISPR clusters that confirm the safety and quality for human health.

Lactobacilli isolated from various sources were identified on the basis of 16S–23S rRNA gene intergenic region amplification and subsequent sequencing of the smaller intergenic region. An in vitro analysis of probiotic properties including binding, ability to tolerate different concentrations of bile, survival in acidic buffer and antimicrobial activity of four different isolates and two standard strains (Lactobacillus plantarum American Type Culture Collection (ATCC) 8014 and L. rhamnosus GG (LGG)) was carried out. The ability of each isolate to stimulate Caco-2 cells, human peripheral blood mononuclear cells (PBMC) and THP-1 cells resulting in immunomodulation of these cells was analysed. Isolates L. rhamnosus CS25 and L. delbrueckii M and standard strain ATCC 8014 showed broad antimicrobial activity, and isolates CS25 (percentage of survival 6·9 % at pH 2·5, 5·1 % at pH 2·0) and L. plantarum CS23 (5·7 % at pH 2·5, 4·9 % at pH 2·0) have shown good tolerance to acidic pH. Isolate CS23 showed a good survival (14 %) after 2 h incubation in de Man, Rogosa and Sharpe (MRS) medium containing 3 % bile salts. Isolates CS23, CS25 and L. fermentum ASt1 could stimulate Caco-2 cells, human PBMC and THP-1 cells for a strong and varied immunomodulatory response in these cells. Though LGG showed poor antimicrobial activity as well as bile and acid tolerance, it was found to be the best binding strain tested. Child faecal isolate CS23 from the present study showed high binding ability (seventeen bacteria/Caco-2), high tolerance to acidic pH and bile salts and significant immunomodulation; therefore it is a good potential probiotic candidate.

Lactobacillus delbrueckii subsp. bulgaricus is one of the most widely used starter culture strains in industrial fermented dairy manufacture. It is also common in naturally fermented dairy foods made using traditional methods. The subsp. bulgaricus strains found in naturally fermented foods may be useful for improving current industrial starter cultures; however, little is known regarding its genetic diversity and population structure. Here, a collection of 298 L . delbrueckii strains from naturally fermented products in Mongolia, Russia and West China was analyzed by multi-locus sequence typing based on eight conserved genes. The 251 confirmed subsp. bulgaricus strains produced 106 unique sequence types, the majority of which were assigned to five clonal complexes (CCs). The geographical distribution of CCs was uneven, with CC1 dominated by Mongolian and Russian isolates and CC2–CC5 isolates exclusively from Xinjiang, China. Population structure analysis suggested six lineages, L1–L6, with various homologous recombination rates. Although L2–L5 were mainly restricted within specific regions, strains belonging to L1 and L6 were observed in diverse regions, suggesting historical transmission events. These results greatly enhance our knowledge of the population diversity of subsp. bulgaricus strains and suggest that strains from CC1 and L4 may be useful as starter strains in industrial fermentation.