Do nomadic lactobacilli fit as potential vaginal probiotics? The answer lies in a successful selective multi-step and scoring approach.

BACKGROUND: The goal of this study was to create a multi-strain probiotic gel that would foster a lactobacilli-dominated vaginal microbiota in pregnant women and ensure appropriate eubiosis for the newborn. Nomadic lactobacilli (95 strains), mostly isolated from food sources, were preliminarily screened for functional traits before being characterized for their capability to inhibit the two vaginal pathogens Streptococcus agalactiae and Candida albicans, which may lead to adverse pregnancy-related outcomes. Eight best-performing strains were chosen and furtherly investigated for their ability to produce biofilm. Lastly, the two selected potential probiotic candidates were analyzed in vitro for their ability to reduce the inflammation caused by C. albicans infection on the reconstituted human vaginal epithelium (HVE). RESULTS: Lactiplantibacillus plantarum produced both isomers of lactic acid, while Lacticaseibacillus paracasei produced only L-isomer. The production of hydrogen peroxide was strain-dependent, with the highest concentrations found within Lact. paracasei strains. The auto-aggregation capacity and hydrophobicity traits were species-independent. S. agalactiae 88II3 was strongly inhibited both at pH 7.0 and 4.0, whereas the inhibition of C. albicans UNIBZ54 was less frequent. Overall, L. plantarum strains had the highest pathogen inhibition and functional scoring. L. plantarum C5 and POM1, which were selected as potential probiotic candidates also based on their ability to form biofilms, were able to counteract the inflammation process caused by C. albicans infection in the HVE model. CONCLUSIONS: Our multi-step and cumulative scoring-based approach was proven successful in mining and highlighting the probiotic potential of two nomadic lactobacilli strains (L. plantarum C5 and POM1), being applicable to preserve and improve human vaginal health.

How multiple farming conditions correlate with the composition of the raw cow's milk lactic microbiome.

Questionnaires on farming conditions were retrieved from 2129 dairy farms and clustered, resulting in 106 representative raw cow's milk samples analysed in winter and summer. Substantiating the efficiency of our survey, some farming conditions affected the milk physicochemical composition. Culturing identified several species of lactic acid bacteria (LAB) per milk, whose number increased through 16S ribosomal RNA (rRNA) gene sequencing and shotgun metagenome analyses. Season, indoor versus outdoor housing, cow numbers, milk substitutes, ratio cattle/rest area, house care system during lactation, and urea and medium-chain fatty acids correlated with the overall microbiome composition and the LAB diversity within it. Shotgun metagenome detected variations in gene numbers and uniqueness per milk. LAB functional pathways differed among milk samples. Focusing on amino acid metabolisms and matching the retrieved annotated genes versus non-starter lactic acid bacteria (NSLAB) references from KEGG and corresponding to those identified, all samples had the same gene spectrum for each pathway. Conversely, gene redundancy varied among samples and agreed with NSLAB diversity. Milk samples with higher numbers of NSLAB species harboured higher number of copies per pathway, which would enable steady-state towards perturbations. Some farming conditions, which affected the microbiome richness, also correlated with the NSLAB composition and functionality.

Mesorhizobium comanense sp. nov., isolated from groundwater.

Strain 3P27G6T was isolated from an artesian well connected to the thermal water basin of Comano Terme, Province of Trento, Italy. In phylogenetic analyses based on multilocus sequence analysis, strain 3P27G6T clustered together with Mesorhizobium australicum WSM2073T. Genome sequencing produced a 99.51 % complete genome, with a length of 7 363 057 bp and G+C content of 63.53 mol%, containing 6897 coding sequences, 55 tRNA and three rRNA. Average nucleotide identity analysis revealed that all distances calculated between strain 3P27G6T and the other Mesorhizobium genomes were below 0.9, indicating that strain 3P27G6T represents a new species. Therefore, we propose the name Mesorhizobium comanense sp. nov. with the type strain 3P27G6T (=DSM 110654T=CECT 30067T). Strain 3P27G6T is a Gram-negative, rod-shaped, aerobic bacterium. Growth condition, antibiotic susceptibility, metabolic and fatty acid-methyl esters profiles of the strain were determined. Only few nodulation and nitrogen fixation genes were found in the genome, suggesting that this strain may not be specialized in nodulation or in nitrogen fixation.

The sourdough fermentation is the powerful process to exploit the potential of legumes, pseudo-cereals and milling by-products in baking industry.

In the era of fighting wastes and paying close attention to sustainability and new protein sources, legumes, pseudo-cereals and milling by-products deserve all the efforts for increasing their consumption. Even with obvious peculiarities, a common trait characterizes these heterogeneous matrixes: unquestionable nutritional and functional value combined with some technological, sensory and/or anti-nutritional weaknesses, which unfortunately limit the exploitation and consumption. With the perspective of their use to fortify staple baked goods, we reviewed the main technological, nutritional and functional features of various legumes and pseudo-cereals, and milling by-products. Notwithstanding the potential of other technological solutions, we reported numerous evidences that qualified the sourdough fermentation as the most sustainable and powerful process to exploit the technological, nutritional and functional features of these matrixes and to limit or eliminate weak attributes. Sourdough fermentations tailored for specific matrixes allowed the fortification of staple baked goods with abundant levels of legumes, pseudo-cereals or milling by-products while keeping high consumer acceptance.

How fructophilic lactic acid bacteria may reduce the FODMAPs content in wheat-derived baked goods: a proof of concept.

BACKGROUND: FODMAPs (Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) intake is associated with the onset of irritable bowel syndrome symptoms. FODMAPs in wheat-derived baked goods may be reduced via bioprocessing by endogenous enzymes and/or microbial fermentation. Because of the inherent enzyme activities, bread made by baker's yeast and sourdough may result in decreased levels of FODMAPs, whose values are, however, not enough low for people sensitive to FODMAPs. RESULTS: Our study investigated the complementary capability of targeted commercial enzymes and metabolically strictly fructophilic lactic acid bacteria (FLAB) to hydrolyze fructans and deplete fructose during wheat dough fermentation. FLAB strains displayed higher fructose consumption rate compared to conventional sourdough lactic acid bacteria. Fructose metabolism by FLAB was faster than glucose. The catabolism of mannitol with the goal of its reuse by FLAB was also investigated. Under sourdough conditions, higher fructans breakdown occurred in FLAB inoculated doughs compared to conventional sourdough bacteria. Preliminary trials allowed selecting Apilactobacillus kunkeei B23I and Fructobacillus fructosus MBIII5 as starter candidates, which were successfully applied in synergy with commercial invertase for low FODMAPs baking. CONCLUSIONS: Results of this study clearly demonstrated the potential of selected strictly FLAB to strongly reduce FODMAPs in wheat dough, especially under liquid-dough and high oxygenation conditions.

High-Value Compounds in Fruit, Vegetable and Cereal Byproducts: An Overview of Potential Sustainable Reuse and Exploitation.

Food waste (FW) represents a global and ever-growing issue that is attracting more attention due to its environmental, ethical, social and economic implications. Although a valuable quantity of bioactive components is still present in the residuals, nowadays most FW is destined for animal feeding, landfill disposal, composting and incineration. Aiming to valorize and recycle food byproducts, the development of novel and sustainable strategies to reduce the annual food loss appears an urgent need. In particular, plant byproducts are a plentiful source of high-value compounds that may be exploited as natural antioxidants, preservatives and supplements in the food industry, pharmaceuticals and cosmetics. In this review, a comprehensive overview of the main bioactive compounds in fruit, vegetable and cereal byproducts is provided. Additionally, the natural and suitable application of tailored enzymatic treatments and fermentation to recover high-value compounds from plant byproducts is discussed. Based on these promising strategies, a future expansion of green biotechnologies to revalorize the high quantity of byproducts is highly encouraging to reduce the food waste/losses and promote benefits on human health.

Fructose-rich niches traced the evolution of lactic acid bacteria toward fructophilic species.

Fructophilic lactic acid bacteria (FLAB) are found in fructose-rich habitats associated with flowers, fruits, fermented foods, and the gastrointestinal tract of several insects having a fructose-based diet. FLAB are heterofermentative lactobacilli that prefer fructose instead of glucose as carbon source, although additional electron acceptor substrates (e.g. oxygen) remarkably enhance their growth on glucose. As a newly discovered bacterial group, FLAB are gaining increasing interest. In this review, the ecological context in which these bacteria exist and evolve was resumed. The wide frequency of isolation of FLAB from fructose feeding insects has been deepened to reveal their ecological significance. Genomic, metabolic data, reductive evolution, and niche specialization of the main FLAB species have been discussed. Findings to date acquired are consistent with a metabolic model in which FLAB display a reliance on environmental niches and the degree of host specificity. In light of FLAB proximity to lactic acid bacteria generally considered to be safe, and due to their peculiar metabolic traits, FLAB may be successfully exploited in food and pharmaceutical applications.

Novel solid-state fermentation of bee-collected pollen emulating the natural fermentation process of bee bread.

Structure of lactic acid bacteria biota in ivy flowers, fresh bee-collected pollen (BCP), hive-stored bee bread, and honeybee gastrointestinal tract was investigated. Although a large microbial diversity characterized flowers and fresh BCP, most of lactic acid bacteria species disappeared throughout the bee bread maturation, giving way to Lactobacillus kunkeei and Fructobacillus fructosus to dominate long stored bee bread and honeybee crop. Adaptation of lactic acid bacteria was mainly related to species-specific, and, more in deep, to strain-specific features. Bee bread preservation seemed related to bacteria metabolites, produced especially by some L. kunkeei strains, which likely gave to lactic acid bacteria the capacity to outcompete other microbial groups. A protocol to ferment BCP was successfully set up, which included the mixed inoculum of selected L. kunkeei strains and Hanseniaspora uvarum AN8Y27B, almost emulating the spontaneous fermentation of bee bread. The strict relationship between lactic acid bacteria and yeasts during bee bread maturation was highlighted. The use of the selected starters increased the digestibility and bioavailability of nutrients and bioactive compounds naturally occurring in BCP. Our biotechnological protocol ensured a product microbiologically stable and safe. Conversely, raw BCP was more exposed to the uncontrolled growth of yeasts, moulds, and other bacterial groups.

How Lactobacillus plantarum shapes its transcriptome in response to contrasting habitats.

Triplets of Lactobacullus plantarum strains were isolated from nine contrasting habitats. Without any passage through other culture media, isolation and cultivation were on model media that strictly reproduced the chemical and physical conditions and stressors of the habitats of origin. Here, we demonstrated how L. plantarum regulates and shapes its transcriptome in response to contrasting habitats. Firstly, multivariate clustering analysis of transcriptional data (RNA-Seq), complemented with metabolomics and phenomics, grouped the strains according to the habitats of origin. Subsequently, selected strains from each habitat switched to repeated cultivation on MRS medium and transcriptomes homogenized into a unique cluster. Adaptation to this common medium mainly relied on activation of genes for phage- and prophage-related proteins and transposases. Finally, the comparison of growth across model media and with respect to MRS medium showed that 44% of the overall 3112 gene transcripts changed depending on the specific habitat. Regulation and shaping of transcriptomes mainly concerned carbohydrate acquisition, pyruvate catabolism, proteolytic system and amino acid, lipid and inorganic ion transport and metabolism, with contrasting responses for contrasting habitats. Pathways reconstruction demonstrated how the large genome size of L. plantarum imparts transcriptome and metabolic flexibility as the basic mechanism for a nomadic lifestyle.

Immune-modulating effects in mouse dendritic cells of lactobacilli and bifidobacteria isolated from individuals following omnivorous, vegetarian and vegan diets.

Lactobacilli and bifidobacteria play a primary role in modulation of gut immunity. By considering that microbiota composition depends on various factors, including diet, we asked whether functional differences could characterize faecal populations of lactobacilli and bifidobacteria isolated from individuals with different dietary habits. 155 healthy volunteers who followed omnivorous, ovo-lacto-vegetarian or vegan diets were recruited at four Italian centres (Turin, Parma, Bologna and Bari). Faecal samples were collected; lactobacilli and bifidobacteria were isolated on selective media and their immunomodulatory activity was tested in mouse dendritic cells (DCs). Pre-incubation with lactobacilli increased LPS-induced expression of the maturation markers CD80 and CD86, whereas pre-incubation with bifidobacteria decreased such expression. Analysis of the cytokine profile indicated that strains of both genera induced down-regulation of IL-12 and up-regulation of IL-10, whereas expression of TNF-α was not modulated. Notably, analysis of anti-inflammatory potential (IL-10/IL-12 ratio) showed that lactobacilli evoked a greater anti-inflammatory effect than did bifidobacteria in the omnivorous group (P<0.05). We also found significantly reduced anti-inflammatory potential in the bacterial strains isolated from Bari's volunteers in comparison with those from the cognate groups from the other centres. In conclusion, lactobacilli and bifidobacteria showed a genus-specific ability of modulating in vitro innate immunity associated with a specific dietary habit. Furthermore, the geographical area had a significant impact on the anti-inflammatory potential of some components of faecal microbiota.

Modulation of the cytokine profile in Caco-2 cells by faecal lactobacilli and bifidobacteria from individuals with distinct dietary habits.

Enterocytes are actively involved in the defense against pathogens and they limit penetration of commensal microbes into tissues. They also have an important role in gut immunity as enterocytes confer mucosal dendritic cell specialisation. On the other hand, the microbiota is directly involved in the development and modulation of the intestinal immune system. Particularly, lactobacilli and bifidobacteria play a primary role in shaping the immune response. We further explored this issue by evaluating whether functional differences in Caco-2 cells could characterise faecal populations of lactobacilli (155 samples) and bifidobacteria (110 samples) isolated from three dietary cohorts (omnivores, ovo-lacto-vegetarians and vegans) recruited at four Italian centres (Turin, Parma, Bologna and Bari). According to our findings, tested bacteria were unable to modulate expression of IL-8, IL-10, TGF-ß or thymic stromal lymphopoietin (TSLP) cytokines in unstimulated Caco-2 cells. Conversely, in phorbol 12-myristate 13-acetate and ionomycin (PMA/Io) stimulated Caco-2 cells, lactobacilli from the omnivorous group and all bifidobacteria significantly down-regulated IL-8. Notably, both genera also lowered the TSLP expression in stimulated Caco-2 cells, regardless of the diet regimen. By further examining these data on the basis of geographical origin, we found that lactobacilli from the vegetarian group recruited in Bari, significantly up-regulated this cytokine. In conclusion, we highlighted a peculiar immune-modulatory activity profile for lactobacilli on enterocytes undergoing a stimulatory signal, which was associated with a specific dietary habit. Furthermore, the geographical area had a significant impact on the inflammatory potential of members of the Lactobacillus genus.

High-level adherence to a Mediterranean diet beneficially impacts the gut microbiota and associated metabolome.

OBJECTIVES: Habitual diet plays a major role in shaping the composition of the gut microbiota, and also determines the repertoire of microbial metabolites that can influence the host. The typical Western diet corresponds to that of an omnivore; however, the Mediterranean diet (MD), common in the Western Mediterranean culture, is to date a nutritionally recommended dietary pattern that includes high-level consumption of cereals, fruit, vegetables and legumes. To investigate the potential benefits of the MD in this cross-sectional survey, we assessed the gut microbiota and metabolome in a cohort of Italian individuals in relation to their habitual diets. DESIGN AND RESULTS: We retrieved daily dietary information and assessed gut microbiota and metabolome in 153 individuals habitually following omnivore, vegetarian or vegan diets. The majority of vegan and vegetarian subjects and 30% of omnivore subjects had a high adherence to the MD. We were able to stratify individuals according to both diet type and adherence to the MD on the basis of their dietary patterns and associated microbiota. We detected significant associations between consumption of vegetable-based diets and increased levels of faecal short-chain fatty acids, Prevotella and some fibre-degrading Firmicutes, whose role in human gut warrants further research. Conversely, we detected higher urinary trimethylamine oxide levels in individuals with lower adherence to the MD. CONCLUSIONS: High-level consumption of plant foodstuffs consistent with an MD is associated with beneficial microbiome-related metabolomic profiles in subjects ostensibly consuming a Western diet. TRIAL REGISTRATION NUMBER: This study was registered at clinical trials.gov as NCT02118857.

Functional proteomics within the genus Lactobacillus.

Lactobacillus are mainly used for the manufacture of fermented dairy, sourdough, meat, and vegetable foods or used as probiotics. Under optimal processing conditions, Lactobacillus strains contribute to food functionality through their enzyme portfolio and the release of metabolites. An extensive genomic diversity analysis was conducted to elucidate the core features of the genus Lactobacillus, and to provide a better comprehension of niche adaptation of the strains. However, proteomics is an indispensable "omics" science to elucidate the proteome diversity, and the mechanisms of regulation and adaptation of Lactobacillus strains. This review focuses on the novel and comprehensive knowledge of functional proteomics and metaproteomics of Lactobacillus species. A large list of proteomic case studies of different Lactobacillus species is provided to illustrate the adaptability of the main metabolic pathways (e.g., carbohydrate transport and metabolism, pyruvate metabolism, proteolytic system, amino acid metabolism, and protein synthesis) to various life conditions. These investigations have highlighted that lactobacilli modulate the level of a complex panel of proteins to growth/survive in different ecological niches. In addition to the general regulation and stress response, specific metabolic pathways can be switched on and off, modifying the behavior of the strains.

Metabolism of Fructophilic Lactic Acid Bacteria Isolated from the Apis mellifera L. Bee Gut: Phenolic Acids as External Electron Acceptors.

Fructophilic lactic acid bacteria (FLAB) are strongly associated with the gastrointestinal tracts (GITs) of Apis mellifera L. worker bees due to the consumption of fructose as a major carbohydrate. Seventy-seven presumptive lactic acid bacteria (LAB) were isolated from GITs of healthy A. mellifera L. adults, which were collected from 5 different geographical locations of the Apulia region of Italy. Almost all of the isolates showed fructophilic tendencies: these isolates were identified as Lactobacillus kunkeei (69%) or Fructobacillus fructosus (31%). A high-throughput phenotypic microarray targeting 190 carbon sources was used to determine that 83 compounds were differentially consumed. Phenotyping grouped the strains into two clusters, reflecting growth performance. The utilization of phenolic acids, such as p-coumaric, caffeic, syringic, or gallic acids, as electron acceptors was investigated in fructose-based medium. Almost all FLAB strains showed tolerance to high phenolic acid concentrations. p-Coumaric acid and caffeic acid were consumed by all FLAB strains through reductases or decarboxylases. Syringic and gallic acids were partially metabolized. The data collected suggest that FLAB require external electron acceptors to regenerate NADH. The use of phenolic acids as external electron acceptors by the 4 FLAB showing the highest phenolic acid reductase activity was investigated in glucose-based medium supplemented with p-coumaric acid. Metabolic responses observed through a phenotypic microarray suggested that FLAB may use p-coumaric acid as an external electron acceptor, enhancing glucose dissimilation but less efficiently than other external acceptors such as fructose or pyruvic acid.IMPORTANCE Fructophilic lactic acid bacteria (FLAB) remain to be fully explored. This study intends to link unique biochemical features of FLAB with their habitat. The quite unique FLAB phenome within the group lactic acid bacteria (LAB) may have practical relevance in food fermentations. The FLAB phenome may have implications for the levels of hexose metabolism products in fermented foods, as well as food probiotication. Due to the harsh conditions of honeybees' GITs, these bacteria had to develop specific physiological and biochemical characteristics, such as tolerance to phenolic acids. The screening of FLAB strains based on metabolic pathways involving phenolic acids may allow the selection of starter cultures with both technological and functional beneficial attributes. Bioconversion of phenolic compounds may contribute to the aroma attributes and biofunctionality of fermented foods. Thus, the selection of FLAB strains as starter cultures with specific enzymatic activities involving phenolic acids may have a promising role in food fermentations.

Cloning, expression and characterization of a ß-D-xylosidase from Lactobacillus rossiae DSM 15814(T).

BACKGROUND: Among the oligosaccharides that may positively affect the gut microbiota, xylo-oligosaccharides (XOS) and arabinoxylan oligosaccharides (AXOS) possess promising functional properties. Ingestion of XOS has been reported to contribute to anti-oxidant, anti-bacterial, immune-modulatory and anti-diabetic activities. Because of the structural complexity and chemical heterogeneity, complete degradation of xylan-containing plant polymers requires the synergistic activity of several enzymes. Endo-xylanases and ß-D-xylosidases, collectively termed xylanases, represent the two key enzymes responsible for the sequential hydrolysis of xylan. Xylanase cocktails are used on an industrial scale for biotechnological purposes. Lactobacillus rossiae DSM 15814(T) can utilize an extensive set of carbon sources, an ability that is likely to contribute to its adaptive ability. In this study, the capacity of this strain to utilize XOS, xylan, D-xylose and L-arabinose was investigated. RESULTS: Genomic and transcriptomic analyses revealed the presence of two gene clusters, designated xyl and ara, encoding proteins predicted to be responsible for XOS uptake and hydrolysis and D-xylose utilization, and L-arabinose metabolism, respectively. The deduced amino acid sequence of one of the genes of the xyl gene cluster, LROS_1108 (designated here as xylA), shows high similarity to (predicted) ß-D-xylosidases encoded by various lactic acid bacteria, and belongs to glycosyl hydrolase family 43. Heterologously expressed XylA was shown to completely hydrolyse XOS to xylose and showed optimal activity at pH 6.0 and 40 °C. Furthermore, ß-D-xylosidase activity of L. rossiae DSM 15814(T) was also measured under sourdough conditions. CONCLUSIONS: This study highlights the ability of L. rossiae DSM 15814(T) to utilize XOS, which is a very useful trait when selecting starters with specific metabolic performances for sourdough fermentation or as probiotics.

Exploitation of Leuconostoc mesenteroides strains to improve shelf life, rheological, sensory and functional features of prickly pear (Opuntia ficus-indica L.) fruit puree.

Strains of Leuconostoc mesenteroides were identified from raw prickly pear (Opuntia ficus-indica L.). Five autochthonous strains were selected based on the kinetics of growth and acidification on prickly pear fruit juice, and the capacity to synthesize exo-polysaccharides. All selected Leuc. mesenteroides strains showed an in vitro mucilage-degrading capability. A protocol for processing and storage of fermented prickly pear fruit puree (FP) was set up. Unstarted FP and chemically acidified FP were used as the controls. Starters grew and remained viable at elevated cell numbers during 21 days of storage at 4 °C. Contaminating Enterobacteriaceae and yeasts were found only in the controls. Viscosity and serum separation distinguished started FP compared to the controls. Colour parameters, browning index, sensory attributes, antimicrobial activity, vitamin C and betalains levels were positively affected by lactic acid fermentation. Increase of free radical scavenging activity in ethyl acetate soluble extract suggested an effect of selected strains on phenolic profiles. Started FP markedly inhibited the inflammatory status of Caco-2/TC7 cells, and also contributed to maintaining the integrity of tight junctions. Started FP scavenged the reactive oxygen species generated by H2O2 on Caco-2 cells. All selected strain variously affected the immunomodulatory activity towards anti- and pro-inflammatory cytokines.

Comparative proteomic analysis of biofilm and planktonic cells of Lactobacillus plantarum DB200.

This study investigated the relative abundance of extracellular and cell wall associated proteins (exoproteome), cytoplasmic proteins (proteome), and related phenotypic traits of Lactobacillus plantarum grown under planktonic and biofilm conditions. Lactobacillus plantarum DB200 was preliminarily selected due to its ability to form biofilms and to adhere to Caco2 cells. As shown by fluorescence microscope analysis, biofilm cells became longer and autoaggregated at higher levels than planktonic cells. The molar ratio between glucose consumed and lactate synthesised was markedly decreased under biofilm compared to planktonic conditions. DIGE analysis showed a differential exoproteome (115 protein spots) and proteome (44) between planktonic and biofilm L. plantarum DB200 cells. Proteins up- or downregulated by at least twofold (p < 0.05) were found to belong mainly to the following functional categories: cell wall and catabolic process, cell cycle and adhesion, transport, glycolysis and carbohydrate metabolism, exopolysaccharide metabolism, amino acid and protein metabolisms, fatty acid and lipid biosynthesis, purine and nucleotide metabolism, stress response, oxidation/reduction process, and energy metabolism. Many of the above proteins showed moonlighting behavior. In accordance with the high expression levels of stress proteins (e.g., DnaK, GroEL, ClpP, GroES, and catalase), biofilm cells demonstrated enhanced survival under conditions of environmental stress.

Effect of Whole-Grain Barley on the Human Fecal Microbiota and Metabolome.

In this study, we compared the fecal microbiota and metabolomes of 26 healthy subjects before (HS) and after (HSB) 2 months of diet intervention based on the administration of durum wheat flour and whole-grain barley pasta containing the minimum recommended daily intake (3 g) of barley ß-glucans. Metabolically active bacteria were analyzed through pyrosequencing of the 16S rRNA gene and community-level catabolic profiles. Pyrosequencing data showed that levels of Clostridiaceae (Clostridium orbiscindens and Clostridium sp.), Roseburia hominis, and Ruminococcus sp. increased, while levels of other Firmicutes and Fusobacteria decreased, from the HSB samples to the HS fecal samples. Community-level catabolic profiles were lower in HSB samples. Compared to the results for HS samples, cultivable lactobacilli increased in HSB fecal samples, while the numbers of Enterobacteriaceae, total coliforms, and Bacteroides, Porphyromonas, Prevotella, Pseudomonas, Alcaligenes, and Aeromonas bacteria decreased. Metabolome analyses were performed using an amino acid analyzer and gas chromatography-mass spectrometry solid-phase microextraction. A marked increase in short-chain fatty acids (SCFA), such as 2-methyl-propanoic, acetic, butyric, and propionic acids, was found in HSB samples with respect to the HS fecal samples. Durum wheat flour and whole-grain barley pasta containing 3% barley ß-glucans appeared to be effective in modulating the composition and metabolic pathways of the intestinal microbiota, leading to an increased level of SCFA in the HSB samples.

Organic cultivation of Triticum turgidum subsp. durum is reflected in the flour-sourdough fermentation-bread axis.

Triticum turgidum subsp. durum was grown according to four farming systems: conventional (CONV), organic with cow manure (OMAN) or green manure (OLEG), and without inputs (NOINPUT). Some chemical and technological characteristics differed between CONV and organic flours. As shown by two-dimensional electrophoresis (2-DE) analysis, OMAN and OLEG flours showed the highest number of gliadins, and OMAN flour also had the highest number of high-molecular-mass glutenins. Type I sourdoughs were prepared at the laboratory level through a back-slopping procedure, and the bacterial ecology during sourdough preparation was described by 16S rRNA gene pyrosequencing. Before fermentation, the dough made with CONV flour showed the highest bacterial diversity. Flours were variously contaminated by genera belonging to the Proteobacteria, Firmicutes, and Actinobacteria. Mature sourdoughs were completely and stably dominated by lactic acid bacteria. The diversity of Firmicutes was the highest for mature sourdoughs made with organic and, especially, NOINPUT flours. Beta diversity analysis based on the weighted UniFrac distance showed differences between doughs and sourdoughs. Those made with CONV flour were separated from the other with organic flours. Lactic acid bacterium microbiota structure was qualitatively confirmed through the culturing method. As shown by PCR-denaturing gradient gel electrophoresis (DGGE) analysis, yeasts belonging to the genera Saccharomyces, Candida, Kazachstania, and Rhodotorula occurred in all sourdoughs. Levels of bound phenolic acids and phytase and antioxidant activities differed depending on the farming system. Mature sourdoughs were used for bread making. Technological characteristics were superior in the breads made with organic sourdoughs. The farming system is another determinant affecting the sourdough microbiota. The organic cultivation of durum wheat was reflected along the flour-sourdough fermentation-bread axis.

Salivary Microbiota Associated with Immunoglobulin A Nephropathy.

This study aimed at investigating the salivary microbiota of 28 patients affected by immunoglobulin A nephropathy (IgAN). Fourteen healthy volunteers (HC) were used as control. Compared to HC, the number of some cultivable bacteria groups (e.g., total anaerobes) significantly (P < 0.05) decreased in the salivary samples of IgAN patients. Total bacteria from salivary samples of IgAN patients and HC subjects were analyzed by pyrosequencing of 16S rRNA gene. Paired t test showed no significant (P > 0.05) differences of alpha-diversity parameters (OTU, ACE, Chao1, and Shannon index) between the salivary samples of HC and IgAN patients. The difference for the community structure was further analyzed using three phylogeny-based beta-diversity measures. Compared to HC, the ratio between Firmicutes/Proteobacteria markedly decreased in IgAN patients. Gemella haemolysins, Granulicatella adiacens, and Veillonella parvula were positively associated (P < 0.05) with HC. Within the phylum Bacteroidetes, Prevotella species (Prevotella nigrescens, Prevotella intermedia, Prevotella pallens, and Prevotella salivae) were the highest in HC. The only exception was for Prevotella aurantiaca. Compared to HC, the percentage of abundance of some species, belonging to Pasteurellaceae family (e.g., Haemophylus parainfluenzae), increased in IgAN patients. Fusobacteriaceae (Fusobacterium) and Corynebacterium sp. also differed between the salivary samples of HC and IgAN patients.