Biofortification as a solution for addressing nutrient deficiencies and malnutrition.

Malnutrition, defined as both undernutrition and overnutrition, is a major global health concern affecting millions of people. One possible way to address nutrient deficiency and combat malnutrition is through biofortification. A comprehensive review of the literature was conducted to explore the current state of biofortification research, including techniques, applications, effectiveness and challenges. Biofortification is a promising strategy for enhancing the nutritional condition of at-risk populations. Biofortified varieties of basic crops, including rice, wheat, maize and beans, with elevated amounts of vital micronutrients, such as iron, zinc, vitamin A and vitamin C, have been successfully developed using conventional and advanced technologies. Additionally, the ability to specifically modify crop genomes to improve their nutritional profiles has been made possible by recent developments in genetic engineering, such as CRISPR-Cas9 technology. The health conditions of people have been shown to improve and nutrient deficiencies were reduced when biofortified crops were grown. Particularly in environments with limited resources, biofortification showed considerable promise as a long-term and economical solution to nutrient shortages and malnutrition. To fully exploit the potential of biofortified crops to enhance public health and global nutrition, issues such as consumer acceptance, regulatory permitting and production and distribution scaling up need to be resolved. Collaboration among governments, researchers, non-governmental organizations and the private sector is essential to overcome these challenges and promote the widespread adoption of biofortification as a key part of global food security and nutrition strategies.

Complete genome sequences of two Leuconostoc carnosum strains: 4010 and AMS1.

Leuconostoc carnosum is a bacterial species commonly associated with meat spoilage. However, some strains exhibit preservative effects due to bacteriocin production. Here, we report the complete genome sequences for two strains, L. carnosum 4010 and AMS1. Bacteriocin-related gene clusters were found on the plasmids of both strains.

Development and properties of functional yoghurt enriched with postbiotic produced by yoghurt cultures using cheese whey and skim milk.

This study aimed to examine the effects of supplementation of postbiotics derived from Streptococcus thermophilus (ST) and Lactobacillus delbrueckii subsp. bulgaricus (LB) in cheese whey (CW) and skim milk (SM) on antioxidant activity, viability of yoghurt starters, and quality parameters of low-fat yoghurt during 22 days of storage. The LB-CW (L delbrueckii ssp. bulgaricus postbiotic-containing cheese whey) sample exhibited the highest antioxidant activity, with 18.71% inhibition (p > 0.05). This sample also showed the highest water holding capacity (77.93%; p < 0.05) and a trend toward receiving the most favorable sensory attributes (p > 0.05) compared to the other samples. The LB-CW and LB-SM yoghurt samples exhibited significantly higher body and texture scores compared to the ST-SM-fortified yoghurt (p < 0.05). However, there was no significant difference in the overall acceptability of the LB-SM and ST-SM yoghurt samples across both starters (p > 0.05). Such findings highlight the potential of postbiotics as functional ingredients to enhance the nutritional and sensory aspects of yoghurt, further contributing to its appeal as a health-promoting product.

Antibiofilm Effect of Curcumin on Saccharomyces boulardii during Beer Fermentation and Bottle Aging.

In a prior study, we elucidated the biofilm formation of Saccharomyces boulardii on glass surfaces during beer bottle aging. Here, we supplemented brewing wort with curcumin at 25 µg/mL concentration to mitigate S. boulardii biofilm and enhance beer's functional and sensory attributes. An assessment encompassing biofilm growth and development, fermentation performance, FLO gene expression, yeast ultrastructure, bioactive content, and consumer acceptance of the beer was conducted throughout fermentation and aging. Crystal violet (CV) and XTT reduction assays unveiled a significant (p < 0.05) reduction in biofilm formation and development. Fluorescent staining (FITC-conA) and imaging with confocal laser scanning microscopy provided visual evidence regarding reduced exopolysaccharide content and biofilm thickness. Transcriptional analyses showed that key adhesins (FLO1, FLO5, FLO9, and FLO10) were downregulated, whereas FLO11 expression remained relatively stable. Although there were initial variations in terms of yeast population and fermentation performance, by day 6, the number of S. boulardii in the test group had almost reached the level of the control group (8.3 log CFU/mL) and remained stable thereafter. The supplementation of brewing wort with curcumin led to a significant (p < 0.05) increase in the beer's total phenolic and flavonoid content. In conclusion, curcumin shows promising potential for use as an additive in beer, offering potential antibiofilm and health benefits without compromising the beer's overall characteristics.

Identification, proteolytic activity quantification and biofilm-forming characterization of Gram-positive, proteolytic, psychrotrophic bacteria isolated from cold raw milk.

Psychrotrophic bacteria of raw milk face the dairy industry with significant spoilage and technological problems due to their ability to produce heat-resistant enzymes and biofilms. Despite extensive information about Gram-negative psychrotrophic bacteria in milk, little is known about Gram-positive psychrotrophic bacteria in milk, and their proteolytic activity and biofilm-forming characteristics. In the present study, Gram-positive, proteolytic, psychrotrophic bacteria of cold raw milk were identified, and their proteolytic activity and biofilm-forming capacity were quantified. In total, 12 genera and 22 species were represented among the bacterial isolates, however 50% belonged to three genera, namely Staphylococcus (19.4%), Bacillus (16.7%), and Enterococcus (13.9%). Different levels of proteolytic activity were detected in the identified isolates, even among the strains belonging to the same species. In addition, proteolytic activity was significantly higher at 25°C than at 7°C for all isolates. The crystal violet staining assay in polystyrene microtitre plates revealed a high level of variation in the biofilm-forming capacity at 7°C. After 72 hours of incubation, 11.1% of the strains did not produce a biofilm, while 27.8%, 52.8%, and 8.3% produced low, moderate, and high amounts of biofilm on polystyrene, respectively. The psychrotrophic bacteria were also able to produce biofilms on the surface of stainless steel coupons in ultra-high temperature milk after 72 h of incubation at 7°C; the number of attached cells ranged from 1.34 to 5.11 log cfu/cm2. These results expand the knowledge related to the proteolytic activity and biofilm-forming capacity of Gram-positive psychrotrophic milk bacteria.

Wild-type Lactococcus lactis producing bacteriocin-like prophage lysins.

Introduction: Lactococcus is a genus of lactic acid bacteria used in the dairy industry as a starter. Lactococci have been found to produce altogether more than 40 different bacteriocins, ribosomally synthesized antimicrobial proteins. All known Lactococcus spp. bacteriocins belong to classes I and II, which are mainly heat-resistant peptides. No class III bacteriocins, bigger heat-sensitive proteins, including phage tail-like bacteriocins, have been found from the Lactococcus spp. Unlike phage tail-like bacteriocins, prophage lysins have not been regarded as bacteriocins, possibly because phage lysins contribute to autolysis, degrading the host's own cell wall. Methods: Wild-type Lactococcus lactis strain LAC460, isolated from spontaneously fermented idli batter, was examined for its antimicrobial activity. We sequenced the genome, searched phage lysins from the culture supernatant, and created knock-out mutants to find out the source of the antimicrobial activity. Results and discussion: The strain LAC460 was shown to kill other Lactococcus strains with protease- and heat-sensitive lytic activity. Three phage lysins were identified in the culture supernatant. The genes encoding the three lysins were localized in different prophage regions in the chromosome. By knock-out mutants, two of the lysins, namely LysL and LysP, were demonstrated to be responsible for the antimicrobial activity. The strain LAC460 was found to be resistant to the lytic action of its own culture supernatant, and as a consequence, the phage lysins could behave like bacteriocins targeting and killing other closely related bacteria. Hence, similar to phage tail-like bacteriocins, phage lysin-like bacteriocins could be regarded as a novel type of class III bacteriocins.

Screening and molecular dynamics simulation of compounds inhibiting MurB enzyme of drug-resistant Mycobacterium tuberculosis: An in-silico approach.

Mycobacterium tuberculosis (MTB) is becoming more and more resistant to drugs and it is a common problem, making current antimicrobials ineffective and highlighting the need for new TB drugs. One of the promising targets for treating MTB is MurB enzymes. This study aimed to identify potential inhibitors of MurB enzymes in M. tuberculosis, as drug resistance among MTB is a significant problem. Attempts are being made to conduct a virtual screening of 30,417 compounds, and thirty-two compounds were chosen for further analysis based on their binding conformations. The selected compounds were assessed for their drug-likeness, pharmacokinetics, and physiochemical characteristics, and seven compounds with binding energy lower than flavin (FAD) were identified. Further, molecular dynamics simulation analysis of these seven compounds found that four of them, namely DB12983, DB15688, ZINC084726167, and ZINC254071113 formed stable complexes with the MurB binding site, exhibiting promising inhibitory activity. These compounds have not been mentioned in any other study, indicating their novelty. The study suggests that these four compounds could be promising candidates for treating MTB, but their effectiveness needs to be validated through in vitro and in vivo experiments. Overall, the findings of this study provide new insight into potential drug targets and candidates for combating drug-resistant MTB.

Pullulanase: unleashing the power of enzyme with a promising future in the food industry.

Pullulanases are the most important industrial group of enzymes in family 13 glycosyl hydrolases. They hydrolyze either α-1,6 and α-1,4 or both glycosidic bonds in pullulan as well as other carbohydrates to produce glucose, maltose, and maltotriose syrups, which have important uses in food and other related sectors. However, very less reports are available on pullulanase production from native strains because of low yield issues. In line with the increasing demands for pullulanase, it has become important to search for novel pullulanase-producing microorganisms with high yields. Moreover, high production costs and low yield are major limitations in the industrial production of pullulanase enzymes. The production cost of pullulanase by using the solid-state fermentation (SSF) process can be minimized by selecting agro-industrial waste. This review summarizes the types, sources, production strategies, and potential applications of pullulanase in different food and other related industries. Researchers should focus on fungal strains producing pullulanase for better yield and low production costs by using agro-waste. It will prove a better enzyme in different food processing industries and will surely reduce the cost of products.

Desulfovibrio bacteria enhance alpha-synuclein aggregation in a Caenorhabditis elegans model of Parkinson's disease.

Introduction: The aggregation of the neuronal protein alpha-synuclein (alpha-syn) is a key feature in the pathology of Parkinson's disease (PD). Alpha-syn aggregation has been suggested to be induced in the gut cells by pathogenic gut microbes such as Desulfovibrio bacteria, which has been shown to be associated with PD. This study aimed to investigate whether Desulfovibrio bacteria induce alpha-syn aggregation. Methods: Fecal samples of ten PD patients and their healthy spouses were collected for molecular detection of Desulfovibrio species, followed by bacterial isolation. Isolated Desulfovibrio strains were used as diets to feed Caenorhabditis elegans nematodes which overexpress human alpha-syn fused with yellow fluorescence protein. Curli-producing Escherichia coli MC4100, which has been shown to facilitate alpha-syn aggregation in animal models, was used as a control bacterial strain, and E. coli LSR11, incapable of producing curli, was used as another control strain. The head sections of the worms were imaged using confocal microscopy. We also performed survival assay to determine the effect of Desulfovibrio bacteria on the survival of the nematodes. Results and Discussion: Statistical analysis revealed that worms fed Desulfovibrio bacteria from PD patients harbored significantly more (P<0.001, Kruskal-Wallis and Mann-Whitney U test) and larger alpha-syn aggregates (P<0.001) than worms fed Desulfovibrio bacteria from healthy individuals or worms fed E. coli strains. In addition, during similar follow-up time, worms fed Desulfovibrio strains from PD patients died in significantly higher quantities than worms fed E. coli LSR11 bacteria (P<0.01). These results suggest that Desulfovibrio bacteria contribute to PD development by inducing alpha-syn aggregation.

Comparative genomics of 40 Weissella paramesenteroides strains.

Weissella strains are often detected in spontaneously fermented foods. Because of their abilities to produce lactic acid and functional exopolysaccharides as well as their probiotic traits, Weissella spp. improve not only the sensorial properties but also nutritional values of the fermented food products. However, some Weissella species have been associated with human and animal diseases. In the era of vast genomic sequencing, new genomic/genome data are becoming available to the public on daily pace. Detailed genomic analyses are due to provide a full understanding of individual Weissella species. In this study, the genomes of six Weissella paramesenteroides strains were de novo sequenced. The genomes of 42 W. paramesenteroides strains were compared to discover their metabolic and functional potentials in food fermentation. Comparative genomics and metabolic pathway reconstructions revealed that W. paramesenteroides is a compact group of heterofermentative bacteria with good capacity of producing secondary metabolites and vitamin Bs. Since the strains rarely harbored plasmid DNA, they did not commonly possess the genes associated with bacteriocin production. All 42 strains were shown to bear vanT gene from the glycopeptide resistance gene cluster vanG. Yet none of the strains carried virulence genes.

Insight into phytase-producing microorganisms for phytate solubilization and soil sustainability.

The increasing demand for food has increased dependence on chemical fertilizers that promote rapid growth and yield as well as produce toxicity and negatively affect nutritional value. Therefore, researchers are focusing on alternatives that are safe for consumption, non-toxic, cost-effective production process, and high yielding, and that require readily available substrates for mass production. The potential industrial applications of microbial enzymes have grown significantly and are still rising in the 21st century to fulfill the needs of a population that is expanding quickly and to deal with the depletion of natural resources. Due to the high demand for such enzymes, phytases have undergone extensive research to lower the amount of phytate in human food and animal feed. They constitute efficient enzymatic groups that can solubilize phytate and thus provide plants with an enriched environment. Phytases can be extracted from a variety of sources such as plants, animals, and microorganisms. Compared to plant and animal-based phytases, microbial phytases have been identified as competent, stable, and promising bioinoculants. Many reports suggest that microbial phytase can undergo mass production procedures with the use of readily available substrates. Phytases neither involve the use of any toxic chemicals during the extraction nor release any such chemicals; thus, they qualify as bioinoculants and support soil sustainability. In addition, phytase genes are now inserted into new plants/crops to enhance transgenic plants reducing the need for supplemental inorganic phosphates and phosphate accumulation in the environment. The current review covers the significance of phytase in the agriculture system, emphasizing its source, action mechanism, and vast applications.

Finger Millet (Eleusine coracana) Plant-Endophyte Dynamics: Plant Growth, Nutrient Uptake, and Zinc Biofortification.

Endophytic fungi and bacteria were isolated from finger millet and their effects on finger millet growth parameters and zinc and NPK contents in grains were studied. Out of 70 fungal and 112 bacterial endophytes, the two best fungal and bacterial isolates were selected on the basis of zinc solubilization and plant-growth-promoting attributes. The fungal isolates identified were Aspergillus terreus and Lecanicillium sp., and the bacterial isolates were Pseudomonas bijieensis and Priestia megaterium. The endophytic zinc, NPK mobilization, and plant-growth-promoting efficacy were determined in a pot experiment with zinc carbonate as the zinc source. Endophytic-primed plants showed enhanced shoot and root lengths compared to the unprimed control. Endophytes increased the zinc content in grains by between 12.12% and 18.80% compared to control plants. Endophytes also augmented the NPK concentrations in seeds compared to control plants and exhibited stability in a diverse range of pHs, temperatures, and NaCl concentrations, and exhibited growth on various carbohydrate and nitrogen sources. This is the first study reporting the interaction of Aspergillus terreus, Lecanicillium sp., Pseudomonas bijieensis, and Priestia megaterium with finger millet for grain Zn biofortification and NPK concentration enhancement. This study indicated that zinc-dissolving endophytes possess the potential for enhancing the zinc and NPK content in grains in addition to the plant-growth-promoting attributes.

Genomics, Proteomics, and Metabolomics Approaches to Improve Abiotic Stress Tolerance in Tomato Plant.

To explore changes in proteins and metabolites under stress circumstances, genomics, proteomics, and metabolomics methods are used. In-depth research over the previous ten years has gradually revealed the fundamental processes of plants' responses to environmental stress. Abiotic stresses, which include temperature extremes, water scarcity, and metal toxicity brought on by human activity and urbanization, are a major cause for concern, since they can result in unsustainable warming trends and drastically lower crop yields. Furthermore, there is an emerging reliance on agrochemicals. Stress is responsible for physiological transformations such as the formation of reactive oxygen, stomatal opening and closure, cytosolic calcium ion concentrations, metabolite profiles and their dynamic changes, expression of stress-responsive genes, activation of potassium channels, etc. Research regarding abiotic stresses is lacking because defense feedbacks to abiotic factors necessitate regulating the changes that activate multiple genes and pathways that are not properly explored. It is clear from the involvement of these genes that plant stress response and adaptation are complicated processes. Targeting the multigenicity of plant abiotic stress responses caused by genomic sequences, transcripts, protein organization and interactions, stress-specific and cellular transcriptome collections, and mutant screens can be the first step in an integrative approach. Therefore, in this review, we focused on the genomes, proteomics, and metabolomics of tomatoes under abiotic stress.

Antifungal metabolites, their novel sources, and targets to combat drug resistance.

Excessive antibiotic prescriptions as well as their misuse in agriculture are the main causes of antimicrobial resistance which poses a growing threat to public health. It necessitates the search for novel chemicals to combat drug resistance. Since ancient times, naturally occurring medicines have been employed and the enormous variety of bioactive chemicals found in nature has long served as an inspiration for researchers looking for possible therapeutics. Secondary metabolites from microorganisms, particularly those from actinomycetes, have made it incredibly easy to find new molecules. Different actinomycetes species account for more than 70% of naturally generated antibiotics currently used in medicine, and they also produce a variety of secondary metabolites, including pigments, enzymes, and anti-inflammatory compounds. They continue to be a crucial source of fresh chemical diversity and a crucial component of drug discovery. This review summarizes some uncommon sources of antifungal metabolites and highlights the importance of further research on these unusual habitats as a source of novel antimicrobial molecules.

Pseudomonas fluorescens group bacterial strains interact differently with pathogens during dual-species biofilm formation on stainless steel surfaces in milk.

In order to develop strategies for preventing biofilm formation in the dairy industry, a deeper understanding of the interaction between different species during biofilm formation is necessary. Bacterial strains of the P. fluorescens group are known as the most important biofilm-formers on the surface of dairy processing equipment that may attract and/or shelter other spoilage or pathogenic bacteria. The present study used different strains of the P. fluorescens group as background microbiota of milk, and evaluated their interaction with Staphylococcus aureus, Bacillus cereus, Escherichia coli O157:H7, and Salmonella Typhimurium during dual-species biofilm formation on stainless steel surfaces. Two separate scenarios for dual-species biofilms were considered: concurrent inoculation of Pseudomonas and pathogen (CI), and delayed inoculation of pathogen to the pre-formed Pseudomonas biofilm (DI). The gram-positive pathogens used in this study did not form dual-species biofilms with P. fluorescens strains unless they were simultaneously inoculated with Pseudomonas strains. E. coli O157:H7 was able to form dual-species biofilms with all seven P. fluorescens group strains, both in concurrent (CI) and delayed (DI) inoculation. However, the percentage of contribution varied depending on the P. fluorescens strains and the inoculation scenario. S. Typhimurium contributed to biofilm formation with all seven P. fluorescens group strains under the CI scenario, with varying degrees of contribution. However, under the DI scenario, S. Typhimurium did not contribute to the biofilm formed by three of the seven P. fluorescens group strains. Overall, these are the first results to illustrate that the strains within the P. fluorescens group have significant differences in the formation of mono-or dual-species biofilms with pathogenic bacteria. Furthermore, the possibility of forming dual-species biofilms with pathogens depends on whether the pathogens form the biofilm simultaneously with the P. fluorescens group strains or whether these strains have already formed a biofilm.

Comparative antioxidant potential of kefir and yogurt of bovine and non-bovine origins.

The aim of this study was to compare the antioxidant potential of the yogurt and kefir produced from ewe, camel, goat, and cow milk. The antioxidant activity of the samples was assessed by measuring total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, ferric reducing antioxidant power (FRAP) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical reducing capacity during 20-day storage at 4 ºC. Kefir and yogurt prepared from ewe and camel milk had significantly higher antioxidative potential than samples made from goat and cow milk (P < 0.05). Ewe kefir (74.55-80.11 mg GAE 100 mL-1) showed the highest TPC followed by cow kefir (65-73.15 mg GAE 100 mL-1), camel kefir (61.2-69.91 mg GAE 100 mL-1) and goat kefir (58.31-73.5 mg GAE 100 mL-1) (P < 0.05). Camel yogurt possesses the highest TPC (56.5-68.25 mg GAE 100 mL-1) followed by ewe (40.32-46.5 mg GAE 100 mL-1), cow (29.5-35.5 mg GAE 100 mL-1) and goat (20.03-26.85 mg GAE 100 mL-1) yogurt (P < 0.05). According to DPPH, FRAP, and ABTS results, the antioxidant activity of samples was as follows in descending order: ewe kefir, camel kefir, ewe yogurt, camel yogurt, cow kefir, goat kefir, goat yogurt, cow yogurt. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05139-9.

Antifungal Preservation of Food by Lactic Acid Bacteria.

Fungal growth and consequent mycotoxin release in food and feed threatens human health, which might even, in acute cases, lead to death. Control and prevention of foodborne poisoning is a major task of public health that will be faced in the 21st century. Nowadays, consumers increasingly demand healthier and more natural food with minimal use of chemical preservatives, whose negative effects on human health are well known. Biopreservation is among the safest and most reliable methods for inhibiting fungi in food. Lactic acid bacteria (LAB) are of great interest as biological additives in food owing to their Generally Recognized as Safe (GRAS) classification and probiotic properties. LAB produce bioactive compounds such as reuterin, cyclic peptides, fatty acids, etc., with antifungal properties. This review highlights the great potential of LAB as biopreservatives by summarizing various reported antifungal activities/metabolites of LAB against fungal growth into foods. In the end, it provides profound insight into the possibilities and different factors to be considered in the application of LAB in different foods as well as enhancing their efficiency in biodetoxification and biopreservative activities.

Lacticaseibacillus rhamnosus GG Survival and Quality Parameters in Kefir Produced from Kefir Grains and Natural Kefir Starter Culture.

The study aimed to determine the effect of starter cultures (kefir grains and natural kefir starter culture without grains) on Lacticaseibacillus rhamnosus GG (LGG) survival and on the quality characteristics of kefir. To this end, the viability of probiotic L. rhamnosus GG strain and the rheological properties and quality parameters of kefir beverages were tested during storage over 21 days at 4 °C. The final LGG counts were 7.71 and 7.55 log cfu/mL in natural kefir starter culture and kefir grain, respectively. When prepared with probiotic bacteria, the syneresis values of kefir prepared using natural kefir starter culture was significantly lower (p < 0.05) than that of kefir made using grains. However, the viscosity indices, hysteresis loop, and dynamic moduli were similar between kefir made with natural kefir starter culture and other kefir formulations (p > 0.05). Moreover, all samples showed shear-thinning behavior. The flavor scores for kefir prepared using natural kefir starter culture were significantly higher than for the other samples (p < 0.05), but overall acceptability was similar at the 10-day assessment across both starters (with and without grain) after the addition of probiotic bacteria (p > 0.05). Overall, the results indicate that natural kefir starter culture could be a potential probiotic carrier.

A novel co-cultivation strategy to generate low-crystallinity bacterial cellulose and increase nisin yields.

In this study, a co-culturing Enterobacter sp. and Lactococcus lactis strategy was developed to alter bacterial cellulose (BC) properties and increase nisin yields. We generated high nisin yields (6260 IU/mL) by altering inoculum ratios and inoculation times in a novel co-culture system. Critically, these were 85% higher than L. lactis monocultures. By monitoring fermentation broth pH and lactic acid yields, the pH was higher and lactic acid yields lower during co-culture conditions when compared with L. lactis monocultures, suggesting that co-culturing was more suitable for L. lactis nisin production. We also determined BC film yields and properties (BC, BC-N, and BC-N after nisin release). BC yields produced by co-culturing were not very different from Enterobacter sp. monocultures, but crystallinity was significantly altered. Collectively, our co-culture system adequately and economically modified BC fibers by interfering with self-assembly and crystallization processes during BC synthesis, with significantly improved nisin yields.

Desulfovibrio Bacteria Are Associated With Parkinson's Disease.

Parkinson's disease (PD) is the most prevalent movement disorder known and predominantly affects the elderly. It is a progressive neurodegenerative disease wherein α-synuclein, a neuronal protein, aggregates to form toxic structures in nerve cells. The cause of Parkinson's disease (PD) remains unknown. Intestinal dysfunction and changes in the gut microbiota, common symptoms of PD, are evidently linked to the pathogenesis of PD. Although a multitude of studies have investigated microbial etiologies of PD, the microbial role in disease progression remains unclear. Here, we show that Gram-negative sulfate-reducing bacteria of the genus Desulfovibrio may play a potential role in the development of PD. Conventional and quantitative real-time PCR analysis of feces from twenty PD patients and twenty healthy controls revealed that all PD patients harbored Desulfovibrio bacteria in their gut microbiota and these bacteria were present at higher levels in PD patients than in healthy controls. Additionally, the concentration of Desulfovibrio species correlated with the severity of PD. Desulfovibrio bacteria produce hydrogen sulfide and lipopolysaccharide, and several strains synthesize magnetite, all of which likely induce the oligomerization and aggregation of α-synuclein protein. The substances originating from Desulfovibrio bacteria likely take part in pathogenesis of PD. These findings may open new avenues for the treatment of PD and the identification of people at risk for developing PD.