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BACKGROUND: Gut lactobacilli can affect the metabolic functions of healthy humans. We tested whether a 1500 kcal/d diet supplemented with cheese containing the probiotic Lactobacillus plantarum TENSIA (Deutsche Sammlung für Mikroorganismen, DSM 21380) could reduce some symptoms of metabolic syndrome in Russian adults with obesity and hypertension. METHODS: In this 3-week, randomized, double-blind, placebo-controlled, parallel pilot study, 25 subjects ingested probiotic cheese and 15 ingested control cheese. Fifty grams of each cheese provided 175 kcal of energy. Blood pressure (BP), anthropometric characteristics, markers of liver and kidney function, metabolic indices (plasma glucose, lipids, and cholesterol), and urine polyamines were measured. Counts of fecal lactobacilli and L. plantarum TENSIA were evaluated using molecular methods. The data were analyzed by t-test for independent samples and Spearman’s partial correlation analysis. RESULTS: The probiotic L. plantarum TENSIA was present in variable amounts (529.6 ± 232.5 gene copies) in 16/25 (64%) study subjects. Body mass index (BMI) was significantly reduced (p = 0.031) in the probiotic cheese group versus the control cheese group. The changes in BMI were closely associated with the water content of the body (r = 0.570, p = 0.0007) when adjusted for sex and age. Higher values of intestinal lactobacilli after probiotic cheese consumption were associated with higher BMI (r = 0.383, p = 0.0305) and urinary putrescine content (r = 0.475, p = 0.006). In patients simultaneously treated with BP-lowering drugs, similar reductions of BP were observed in both groups. A positive association was detected between TENSIA colonization and the extent of change of morning diastolic BP (r = 0.617, p = 0.0248) and a trend toward lower values of morning systolic BP (r = −0.527, p = 0.0640) at the end of the study after adjusting for BMI, age, and sex. CONCLUSION: In a pilot study of obese hypertensive patients, a hypocaloric diet supplemented with a probiotic cheese helps to reduce BMI and arterial BP values, recognized symptoms of metabolic syndrome. TRIAL REGISTRATION: Current Controlled Trials ISRCTN76271778

Bacterial cellulose (BC) is an ecofriendly biopolymer with diverse commercial applications. Its use is limited by the capacity of bacterial production strains and cost of the medium. Mining for novel organisms with well-optimized growth conditions will be important for the adoption of BC. In this study, a novel BC-producing strain was isolated from rotten fruit samples and identified as Lactiplantibacillus plantarum from 16S rRNA sequencing. Culture conditions were optimized for supporting maximal BC production using one variable at a time, Plackett–Burman design, and Box Behnken design approaches. Results indicated that a modified Yamanaka medium supported the highest BC yield (2.7 g/l), and that yeast extract, MgSO 4 , and pH were the most significant variables influencing BC production. After optimizing the levels of these variables through Box Behnken design, BC yield was increased to 4.51 g/l. The drug delivery capacity of the produced BC membrane was evaluated through fabrication with sodium alginate and gentamycin antibiotic at four different concentrations. All membranes (normal and fabricated) were characterized by scanning electron microscope, Fourier transform-infrared spectroscopy, X-ray diffraction, and mechanical properties. The antimicrobial activity of prepared composites was evaluated by using six human pathogens and revealed potent antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus , and Streptococcus mutans , with no detected activity against Pseudomonas aeruginosa and Candida albicans .

Lactiplantibacillus plantarum (L. plantarum) is a well-studied and versatile species of lactobacilli. It is found in several niches, including human mucosal surfaces, and it is largely employed in the food industry and boasts a millenary tradition of safe use, sharing a long-lasting relationship with humans. L. plantarum is generally recognised as safe and exhibits a strong probiotic character, so that several strains are commercialised as health-promoting supplements and functional food products. For these reasons, L. plantarum represents a valuable model to gain insight into the nature and mechanisms of antimicrobials as key factors underlying the probiotic action of health-promoting microbes. Probiotic antimicrobials can inhibit the growth of pathogens in the gut ensuring the intestinal homeostasis and contributing to the host health. Furthermore, they may be attractive alternatives to conventional antibiotics, holding potential in several biomedical applications. The aim of this review is to investigate the most relevant papers published in the last ten years, bioprospecting the antimicrobial activity of characterised probiotic L. plantarum strains. Specifically, it focuses on the different chemical nature, the action spectra and the mechanisms underlying the bioactivity of their antibacterial and antiviral agents. Emerging trends in postbiotics, some in vivo applications of L. plantarum antimicrobials, including strengths and limitations of their therapeutic potential, are addressed and discussed.

Early-life microbial exposure is of particular importance to growth, immune system development and long-lasting health. Hence, early microbiota composition is a promising predictive biomarker for health and disease but still remains poorly characterized in regards to susceptibility to diarrhoea. In the present study, we aimed to assess if gut bacterial community diversity and composition during the suckling period were associated with differences in susceptibility of pigs to post-weaning diarrhoea. Twenty piglets from 5 sows (4 piglets / litter) were weaned in poor housing conditions to challenge their susceptibility to post-weaning diarrhoea. Two weeks after weaning, 13 pigs exhibited liquid faeces during 2 or 3 days and were defined as diarrhoeic (D) pigs. The other 7 pigs did not have diarrhea during the whole post-weaning experimental periodand were defined as healthy (H) pigs. Using a molecular characterisation of fecal microbiota with CE-SSCP fingerprint, Next Generation Sequencing and qPCR, we show that D and H pigs were mainly discriminated as early as postnatal day (PND) 7, i.e. 4 weeks before post-weaning diarrhoea occurence. At PND 7 H pigs displayed a lower evenness and a higher abundance of Prevotellaceae, Lachnospiraceae, Ruminocacaceae and Lactobacillaceae compared to D pigs. The sPLS regression method indicates that these bacterial families were strongly correlated to a higher Bacteroidetes abundance observed in PND 30 H pigs one week before diarrhoea. These results emphasize the potential of early microbiota diversity and composition as being an indicator of susceptibility to post-weaning diarrhoea. Furthermore, they support the health promoting strategies of pig herds through gut microbiota engineering.

Energy conservation in microorganisms is classically categorized into respiration and fermentation; however, recent work shows some species can use mixed or alternative bioenergetic strategies. We explored the use of extracellular electron transfer for energy conservation in diverse lactic acid bacteria (LAB), microorganisms that mainly rely on fermentative metabolism and are important in food fermentations. The LAB Lactiplantibacillus plantarum uses extracellular electron transfer to increase its NAD + /NADH ratio, generate more ATP through substrate-level phosphorylation, and accumulate biomass more rapidly. This novel, hybrid metabolism is dependent on a type-II NADH dehydrogenase (Ndh2) and conditionally requires a flavin-binding extracellular lipoprotein (PplA) under laboratory conditions. It confers increased fermentation product yield, metabolic flux, and environmental acidification in laboratory media and during kale juice fermentation. The discovery of a single pathway that simultaneously blends features of fermentation and respiration in a primarily fermentative microorganism expands our knowledge of energy conservation and provides immediate biotechnology applications. Bacteria produce the energy they need to live through two processes, respiration and fermentation. While respiration is often more energetically efficient, many bacteria rely on fermentation as their sole means of energy production. Respiration normally depends on the presence of small soluble molecules, such as oxygen, that can diffuse inside the cell, but some bacteria can use metals or other insoluble compounds found outside the cell to perform ‘extracellular electron transfer’. Lactic acid bacteria are a large group of bacteria that have several industrial uses and live in many natural environments. These bacteria survive using fermentation, but they also carry a group of genes needed for extracellular electron transfer. It is unclear whether they use these genes for respiration or if they have a different purpose. Tejedor-Sanz, Stevens et al. used a lactic acid bacterium called Lactiplantibacillus plantarum to study whether and how this group of bacteria use extracellular electron transfer. Analysis of L. plantarum and its effect on its surroundings showed that these bacteria use a hybrid process to produce energy: the cells use aspects of extracellular respiration to increase the yield and efficiency of fermentation. Combining these two approaches may allow L. plantarum to adapt to different environments and grow faster, allowing it to compete against other species. Tejedor-Sanz, Stevens et al. provide new information on a widespread group of bacteria that are often used in food production and industry. The next step will be to understand how the hybrid system is controlled and how it varies among species. Understanding this process could result in new biotechnologies and foods that are healthier, produce less waste, or have different tastes and textures.

Bacteriocins are heat-stable ribosomally synthesized antimicrobial peptides produced by various bacteria, including food-grade lactic acid bacteria (LAB). These antimicrobial peptides have huge potential as both food preservatives, and as next-generation antibiotics targeting the multiple-drug resistant pathogens. The increasing number of reports of new bacteriocins with unique properties indicates that there is still a lot to learn about this family of peptide antibiotics. In this review, we highlight our system of fast tracking the discovery of novel bacteriocins, belonging to different classes, and isolated from various sources. This system employs molecular mass analysis of supernatant from the candidate strain, coupled with a statistical analysis of their antimicrobial spectra that can even discriminate novel variants of known bacteriocins. This review also discusses current updates regarding the structural characterization, mode of antimicrobial action, and biosynthetic mechanisms of various novel bacteriocins. Future perspectives and potential applications of these novel bacteriocins are also discussed.

Hyperuricemia is well known as the cause of gout. In recent years, it has also been recognized as a risk factor for arteriosclerosis, cerebrovascular and cardiovascular diseases, and nephropathy in diabetic patients. Foods high in purine compounds are more potent in exacerbating hyperuricemia. Therefore, the development of probiotics that efficiently degrade purine compounds is a promising potential therapy for the prevention of hyperuricemia. In this study, fifty-five lactic acid bacteria isolated from Chinese sauerkraut were evaluated for the ability to degrade inosine and guanosine, the two key intermediates in purine metabolism. After a preliminary screening based on HPLC, three candidate strains with the highest nucleoside degrading rates were selected for further characterization. The tested biological characteristics of candidate strains included acid tolerance, bile tolerance, anti-pathogenic bacteria activity, cell adhesion ability, resistance to antibiotics and the ability to produce hydrogen peroxide. Among the selected strains, DM9218 showed the best probiotic potential compared with other strains despite its poor bile resistance. Analysis of 16S rRNA sequences showed that DM9218 has the highest similarity (99%) to Lactobacillus plantarum WCFS1. The acclimated strain DM9218-A showed better resistance to 0.3% bile salt, and its survival in gastrointestinal tract of rats was proven by PCR-DGGE. Furthermore, the effects of DM9218-A in a hyperuricemia rat model were evaluated. The level of serum uric acid in hyperuricemic rat can be efficiently reduced by the intragastric administration of DM9218-A (P<0.05). The preventive treatment of DM9218-A caused a greater reduction in serum uric acid concentration in hyperuricemic rats than the later treatment (P<0.05). Our results suggest that DM9218-A may be a promising candidate as an adjunctive treatment in patients with hyperuricemia during the onset period of disease. DM9218-A also has potential as a probiotic in the prevention of hyperuricemia in the normal population.

Lactic acid bacteria are well known to be beneficial for food production and, as probiotics, they are relevant for many aspects of health. However, their potential as cell factories for the chemical industry is only emerging. Many physiological traits of these microorganisms, evolved for optimal growth in their niche, are also valuable in an industrial context. Here, we illuminate these features and describe why the distinctive adaptation of lactic acid bacteria is particularly useful when developing a microbial process for chemical production from renewable resources. High carbon uptake rates with low biomass formation combined with strictly regulated simple metabolic pathways, leading to a limited number of metabolites, are among the key factors defining their success in both nature and industry. Studies from food- and health-related sciences shed light on the potential of lactic acid bacteria for microbial chemical production. The extraordinary stress resistance of many lactic acid bacteria against specific stresses (such as butanol) is only emerging, but suggests their usefulness for industrial processes, where these exact stresses often inhibit traditional cell factories. Metabolic models have become available for the rational engineering of lactic acid bacteria. Recent phylogenetic studies allow educated guesses for mining new cell factories. Lactic acid bacteria are well known for their demanding nutrient requirements, but carbon-wise, they can utilize nearly the whole spectrum of natural monosaccharides and offer themselves as biocatalysts for biorefinery applications.

Abstract Gatot, a traditional Indonesian fermented food product made from cassava (Manihot utilissima), is valued for its potential health benefits and contribution towards local food security. As fermentation induces a rich microbial environment that could enhance nutritional properties and produce bioactive compounds, understanding the bacterial communities involved is fundamental for optimizing their health-promoting potential. However, the bacterial diversity of Gatot across different regions remains underexplored. This study aims to detect and identify the bacterial communities in Gatot samples, as well as to measure the differences in their abundance in Gatot from three different regions in Yogyakarta. Gatot samples were collected from Bantul, Gunungkidul, and Kulon Progo regions. Genomic DNA was extracted from the samples, and DNA concentration was measured using NanoDrop and Qubit. Libraries were then prepared with Oxford Nanopore Technology kits. For bacterial identification, the V1-V9 regions of the 16S ribosomal RNA gene were amplified using 27F and 1492R primers under specific polymerase chain reaction conditions. Sequencing was performed on a GridION platform using MinKNOW (version v24.02.16) and Dorado (version v7.3.11) for high-accuracy basecalling. Quality filtering and visualization of FASTQ files were performed using NanoPlot and NanoFilt, while taxonomic classification was referenced against the NCBI 16S RefSeq database. Data analysis was completed in Pavian and RStudio. The dominant bacterial family across all samples was the Lactobacillaceae family. However, each region exhibited unique microbial signatures at the genus level: Bantul samples were dominated by Weissella, Gunungkidul by Leuconostoc, and Kulon Progo by Lactiplantibacillus. Specific species were also predominant in each location, with Weissella confusa in Bantul, Liquorilactobacillus hordei in Gunungkidul, and Lactiplantibacillus plantarum in Kulon Progo. These regional variations highlight how location-specific bacterial communities influence the fermentation profile of Gatot, potentially affecting flavor, texture, and nutritional value. This study provides the first comprehensive metagenomic analysis of Gatot’s bacterial communities across different regions, offering new insights into the influence of geographical environment on microbial composition in fermented cassava products. The findings support the potential for controlled fermentation processes tailored to local microbial ecosystems, to enhance Gatot’s functionality as a health-promoting food and source of probiotic. Resumo Gatot, um produto alimentar fermentado tradicional indonésio feito de mandioca (Manihot utilissima), é valorizado por seus potenciais benefícios à saúde e sua contribuição para a segurança alimentar local. Como a fermentação induz um ambiente microbiano rico que pode melhorar as propriedades nutricionais e produzir compostos bioativos, entender as comunidades bacterianas envolvidas é fundamental para otimizar seu potencial de promoção à saúde. No entanto, a diversidade bacteriana do Gatot em diferentes regiões ainda é pouco explorada. Este estudo tem como objetivo detectar e identificar as comunidades bacterianas em amostras de Gatot, além de medir as diferenças em sua abundância em Gatot de três regiões diferentes de Yogyakarta. Amostras de Gatot foram coletadas das regiões de Bantul, Gunungkidul e Kulon Progo. O DNA genômico foi extraído das amostras, e a concentração de DNA foi medida utilizando o NanoDrop e Qubit, enquanto as bibliotecas foram preparadas com kits da Oxford Nanopore Technology. Para a identificação bacteriana, as regiões V1-V9 do gene 16S do RNA ribossômico foram amplificadas usando os primers 27F e 1492R sob condições específicas de reação em cadeia da polimerase. A sequenciação foi realizada na plataforma GridION usando MinKNOW (v24.02.16) e Dorado (v7.3.11) para uma leitura de bases de alta precisão. A filtragem de qualidade e visualização dos arquivos FASTQ foram realizadas com NanoPlot e NanoFilt, enquanto a classificação taxonômica seguiu o banco de dados NCBI 16S RefSeq. A análise dos dados foi concluída no Pavian e no RStudio. A família bacteriana dominante em todas as amostras foi a Lactobacillaceae. No entanto, cada região exibiu assinaturas microbianas únicas no nível de gênero: as amostras de Bantul foram dominadas por Weissella, as de Gunungkidul por Leuconostoc, e as de Kulon Progo por Lactiplantibacillus. Espécies específicas também foram predominantes em cada local, com Weissella confusa em Bantul, Liquorilactobacillus hordei em Gunungkidul, e Lactiplantibacillus plantarum em Kulon Progo. Essas variações regionais destacam como as comunidades bacterianas específicas de cada local influenciam o perfil de fermentação do Gatot, podendo afetar o sabor, a textura e o valor nutricional. Este estudo fornece a primeira análise metagenômica abrangente das comunidades bacterianas do Gatot em diferentes regiões, oferecendo novas percepções sobre a influência do ambiente geográfico na composição microbiana de produtos fermentados de mandioca. Os achados apoiam o potencial para processos de fermentação controlada, adaptados aos ecossistemas microbianos locais, para melhorar a funcionalidade do Gatot como um alimento promotor de saúde e fonte de probióticos.

Lactic acid bacteria (LAB) constitute a heterogeneous group of microorganisms that produce lactic acid as the major product during the fermentation process. LAB are Gram-positive bacteria with great biotechnological potential in the food industry. They can produce bacteriocins, which are proteinaceous antimicrobial molecules with a diverse genetic origin, posttranslationally modified or not, that can help the producer organism to outcompete other bacterial species. In this review, we focus on the various types of bacteriocins that can be found in LAB and the organization and regulation of the gene clusters responsible for their production and biosynthesis, and consider the food applications of the prototype bacteriocins from LAB. Furthermore, we propose a revised classification of bacteriocins that can accommodate the increasing number of classes reported over the last years.