Core gut microbiota in Jinhua pigs and its correlation with strain,farm and weaning age

Gut microbial diversity and the core microbiota of the Jinhua pig, which is a traditional, slow-growing Chinese breed with a high body-fat content, were examined from a total of 105 fecal samples collected from 6 groups of pigs at 3 weaning ages that originated from 2 strains and were raised on 3 different pig farms. The bacterial community was analyzed following high-throughput pyrosequencing of 16S rRNA genes, and the fecal concentrations of short-chain fatty acids (SCFAs) were measured by gas chromatograph. Our results showed that Firmicutes and Bacteroidetes were the dominant phyla, and Lactobacillus, Streptococcus, Clostridium, SMB53, and Bifidobacterium were the most abundant genera. Fifteen predominant genera present in every Jinhua pig sample constituted a phylogenetic core microbiota and included the probiotics Lactobacillus and Bifidobacterium, and the SCFA-producing bacteria Clostridium, Prevotella, Bacteroides, Coprococcus, Roseburia, Ruminococcus, Blautia, and Butyricicoccus. Comparisons of the microbiota compositions and SCFA concentrations across the 6 groups of pigs demonstrated that genetic background and weaning age affected the structure of the gut microbiota more significantly than the farm. The relative abundance of the core genera in the pigs, including Lactobacillus, Clostridium, Prevotella, Bacteroides, Roseburia, Ruminococcus, Blautia, and Butyricicoccus varied dramatically in pigs among the 2 origins and 3 weaning ages, while Oscillospira, Megasphaera, Parabacteroides, and Corynebacterium differed among pigs from different farms. Interestingly, there was a more significant influence of strain and weaning age than of rearing farm on the SCFA concentrations. Therefore, strain and weaning age appear to be the more important factors shaping the intestinal microbiome of pigs.     

Potential application of genetically identical somatic cell nuclear transfer-cloned dogs for gastrointestinal microbiota analysis

This study investigated the gastrointestinal microbiota in three genetically identical cloned dogs (A, B and C) by somatic cell nuclear transfer. We collected feces from three cloned dogs and their feed to investigate gastrointestinal microbiota using both culture-dependent and culture-independent methods. A total of 962 strains from the feces of cloned dogs were isolated using aerobic and anaerobic culture methods. The dominant microorganisms were Enterococcus faecalis and Enterococcus faecium in all fecal samples. In particular, the fecal sample from cloned dog C had similar proportions of three species (E. faecalis, E. faecium and Lactobacillus murinus). In all, 29 DNA fragments were identified by PCR-denaturing gradient gel electrophoresis (DGGE) analysis. The highest DGGE band intensities were for E. faecalis from cloned dogs A and C and for Clostridium sordellii from cloned dog B, with relative intensities of 15.2, 17.7 and 14.4%, respectively. The other strains identified from the cloned dogs were Chryseobacterium soldanellicola, Escherichia coli, L. murinus, Streptococcus alactolyticus, Weissella confusa and uncultured bacterium. Some microbes isolated from the fecal samples, including C. soldanellicola and W. confuse, were derived from the feed. Overall, gastrointestinal microbiota of all genetically identical cloned dogs, maintained under the same environmental and feeding conditions, showed similar profiles in terms of species diversity analyzed by PCR-DGGE, although there were proportional differences in the amounts of bacterial species. To our knowledge, this is the first report to investigate and compare gastrointestinal microbiota of three genetically identical dogs.     

Broiler chicken cecal microbiocenoses depending on mixed fodder

Molecular genetic techniques (NGS sequencing and quantitative PCR) were used to determine the composition of the cecal bacterial community of broiler chickens fed with different mixed fodder. The cecal microbiome exhibited taxonomic diversity, with both typical inhabitants of avian intestine belonging to the families Clostridiaceae, Eubacteriaceae, and Lactobacillaceae and to the phylum Bacteroidetes, and new unidentified taxa, as well as bacteria of the families Lachnospiraceae and Ruminococcaceae, which were previously considered restricted to the rumen microbiota. Contrary to traditional concepts, enterococci and bifidobacteria were among the minor components of the community, lactate-fermenting species were absent, and typical avian pathogens of the genus Staphylococcus were detected but seldom. Members of the family Suterellaceae and the genus Gallibacterium, which are responsible for avian respiratory infections, were also detected. Significant fluctuations of abundance and composition of microbial groups within the cecal community and of the parameters of broiler productivity were found to occur depending on the feed allowance. Cellulose content in the feed had the most pronounced effect on the composition and structure of bacterial communities. Decreased cellulose content resulted in a decrease of bacterial abundance by an order of magnitude and in increased ratios of members of the phylum Bacteroidetes and the family Clostridiaceae, which possess the enzymes degrading starch polysaccharides. Abundance of the normal inhabitants of avian intestine belonging to the genus Lactobacillus and the order Bacillales decreased, while the share of Escherichia and members of the family Sutterellaceae increased, including some species capable of causing dysbiotic changes in the avian intestine. No significant change in the abundance of cellulolytics of the families Ruminococcaceae, Lachnospiraceae, and Eubacteriaceae was observed.     

Prevalence,quantitative load and genetic diversity of <Emphasis Type="Italic">Campylobacter</Emphasis> spp. in dairy cattle herds in Lithuania

Background

Campylobacteriosis is a zoonotic disease, and animals such as poultry, pigs and cattle may act as reservoirs for Campylobacter spp. Cattle shed Campylobacter spp. into the environment and they can act as a reservoir for human infection directly via contact with cattle or their faeces or indirectly by consumption of contaminated food. The aim of this study was to determine the prevalence, the quantitative load and the genetic strain diversity of Campylobacter spp. in dairy cattle of different age groups.

Results

Faecal samples of 200 dairy cattle from three farms in the central part of Lithuania were collected and examined for Campylobacter. Cattle herds of all three farms were Campylobacter spp. positive, with a prevalence ranging from 75% (farm I), 77.5% (farm II) to 83.3% (farm III). Overall, the highest prevalence was detected in calves (86.5%) and heifers (86.2%). In contrast, the lowest Campylobacter prevalence was detectable in dairy cows (60.6%). C. jejuni, C. coli, C. lari and C. fetus subsp. fetus were identified in faecal samples of dairy cattle. C. upsaliensis was not detectable in any sample. The high counts of Campylobacter spp. were observed in faecal material of dairy cattle (average 4.5 log₁₀ cfu/g). The highest numbers of Campylobacter spp. were found in faecal samples from calves (average 5.3 log₁₀ cfu/g), whereas, faecal samples from cows harboured the lowest number of Campylobacter spp. (average 3.7 log₁₀ cfu/g). Genotyping by fla A PCR-RFLP analysis of selected C. jejuni isolates showed that some genotypes were present in all farms and all age groups. However, farm or age specific genotypes were also identified.

Conclusions

Future studies are needed to investigate risk factors related to the degree of colonisation in cattle. Based on that, possible measures to reduce the colonisation and subsequent shedding of Campylobacter in cattle could be established. It is important to further investigate the epidemiology of Campylobacter in the cattle population in order to assess associated risks to public health.

     

Composition and diversity of the bacterial community in snow leopard (<Emphasis Type="Italic">Uncia uncia</Emphasis>) distal gut

Intestinal microflora influences many essential metabolic functions, and is receiving increasing attention from the scientific community. However, information on intestinal microbiota, especially for large wild carnivores, is insufficient. In the present study, the bacterial community in the feces of snow leopards (Uncia uncia) was described based on 16S rRNA gene sequence analysis. A total of 339 near-full-length 16S rRNA gene sequences representing 46 non-redundant bacterial phylotypes (operational taxonomical units, OTUs) were identified in fecal samples from four healthy snow leopards. Four different bacterial phyla were identified: Firmicutes (56.5 %), Actinobacteria (17.5 %), Bacteroidetes (13 %), and Proteobacteria (13 %). The phylum Actinobacteria was the most abundant lineage, with 40.4 % of all identified clones, but Clostridiales, with 50 % of all OTUs, was the most diverse bacterial order. The order Clostridiales was affiliated with four families: Clostridiaceae I, Lachnospiraceae, Peptostreptococcaceae, and Ruminococcaceae. Lachnospiraceae was the most diverse family with 17 OTUs identified. These findings were basically consistent with previous reports on the bacterial diversity in feces from other mammals.     

Alterations in gut bacterial and fungal microbiomes are associated with bacterial Keratitis,an inflammatory disease of the human eye

Dysbiosis, or imbalance in the gut microbiome, has been implicated in auto-immune, inflammatory, neurological diseases as well as in cancers. More recently it has also been shown to be associated with ocular diseases. In the present study, the association of gut microbiome dysbiosis with bacterial Keratitis, an inflammatory eye disease which significantly contributes to corneal blindness, was investigated. Bacterial and fungal gut microbiomes were analysed using fecal samples of healthy controls (HC, n?=?21) and bacterial Keratitis patients (BK, n?=?19). An increase in abundance of several anti-inflammatory organisms including Dialister, Megasphaera, Faecalibacterium, Lachnospira, Ruminococcus and Mitsuokella and members of Firmicutes, Veillonellaceae, Ruminococcaceae and Lachnospiraceae was observed in HC compared to BK patients in the bacterial microbiome. In the fungal microbiome, a decrease in the abundance of Mortierella, Rhizopus, Kluyveromyces, Embellisia and Haematonectria and an increase in the abundance of pathogenic fungi Aspergillus and Malassezia were observed in BK patients compared to HC. In addition, heatmaps, PCoA plots and inferred functional profiles also indicated significant variations between the HC and BK microbiomes, which strongly suggest dysbiosis in the gut microbiome of BK patients. This is the first study demonstrating the association of gut microbiome with the pathophysiology of BK and thus supports the gut–eye axis hypothesis. Considering that Keratitis affects about 1 million people annually across the globe, the data could be the basis for developing alternate strategies for treatment like use of probiotics or fecal transplantation to restore the healthy microbiome as a treatment protocol for Keratitis.     

Comparative analysis of fecal microflora of healthy full-term Indian infants born with different methods of delivery (vaginal vs cesarean): <Emphasis Type="Italic">Acinetobacter</Emphasis> sp<Emphasis Type="Italic">.</Emphasis> prevalence in vaginally born infants

In this study fecal microflora of human infants born through vaginal delivery (VB) and through cesarean section (CB) were investigated using culture-independent 16S rDNA cloning and sequencing approach. The results obtained clearly revealed that fecal microbiota of VB infants distinctly differ from those in their counterpart CB infants. The intestinal microbiota of infants delivered by cesarean section appears to be more diverse, in terms of bacteria species, than the microbiota of vaginally delivered infants. The most abundant bacterial species present in VB infants were Acinetobacter sp., Bifidobacterium sp. and Staphylococcus sp. However, CB infant’s fecal microbiota was dominated with Citrobacter sp., Escherichia coli and Clostridium difficile. The intestinal microbiota of cesarean section delivered infants in this study was also characterized by an absence of Bifidobacteria species. An interesting finding of our study was recovery of large number of Acinetobacter sp. consisting of Acinetobacter pittii (former Acinetobacter genomic species 3), Acinetobacter junii and Acinetobacter baumannii in the VB infants clone library. Among these, Acinetobacter baumannii is a known nosocomial pathogen and Acinetobacter pittii (genomic species 3) is recently recognized as clinically important taxa within the Acinetobacter calcoaceticus–Acinetobacter baumannii (ACB) complex. Although none of the infants had shown any sign of clinical symptoms of disease, this observation warrants a closer look.     

Antibiotic-Resistant Genes and Pathogens Shed by Wild Deer Correlate with Land Application of Residuals

The purpose of this study was to investigate genetic biomarkers of zoonotic enteric pathogens and antibiotic-resistant genes (ARGs) in the feces of white-tailed deer (Odocoileus virginianus) as related to proximity of deer to land that receives livestock manure or human waste biosolid fertilizers. Deer feces were collected in the St. Lawrence River Valley and Adirondack State Park of New York. Campylobacter spp. 16S rDNA was detected in 12 of 232 fecal samples (8 of 33 sites). Salmonellae were cultivated from 2 of 182 fecal samples (2 of 29 sites). Genetic virulence markers for Shiga-like toxin I (stx₁) and enterohemolysin (hylA) were each detected in one isolate of Escherichia coli; E. coli O157 was not detected in any of 295 fecal samples. ARGs detected in deer feces included ermB (erythromycin-resistant gene; 9 of 295 fecal samples, 5 of 38 sites), vanA (vancomycin-resistant gene; 93 of 284 samples, 33 of 38 sites), tetQ (tetracycline-resistant gene; 93 of 295 samples, 25 of 38 sites), and sul(I) (sulfonamide-resistant gene; 113 of 292 samples, 28 of 38 sites). Genetic markers of pathogens and ARGs in deer feces were spatially associated with collection near concentrated animal feeding operations (CAFOs; Campylobacter spp., tetQ, and ermB) and land-applied biosolids (tetQ). These results indicate that contact with human waste biosolids or animal manure may be an important method of pathogen and ARG transmission and that deer in proximity to land-applied manure and human waste biosolids pose increased risk to nearby produce and water quality.     

Lactobacilli-Host mutualism: &quot;learning on the fly&quot;

Metazoans establish with microorganisms complex interactions for their mutual benefits. Drosophila, which has already proven useful host model to study several aspects of innate immunity and host-bacteria pathogenic associations has become a powerful model to dissect the mechanisms behind mutualistic host-microbe interactions. Drosophila microbiota is composed of simple and aerotolerant bacterial communities mostly composed of Lactobacillaceae and Acetobactereaceae. Drosophila mono- or poly-associated with lactobacilli strains constitutes a powerful model to dissect the complex interplay between lactobacilli and host biologic traits. Thanks to the genetic tractability of both Drosophila and lactobacilli this association model offers a great opportunity to reveal the underlying molecular mechanisms. Here, we review our current knowledge about how the Drosophila model is helping our understanding of how lactobacilli shapes host biology.     

Composition and abundance of microbiota in the pharynx in patients with laryngeal carcinoma and vocal cord polyps

The pharynx is an important site of microbiota colonization, but the bacterial populations at this site have been relatively unexplored by culture-independent approaches. The aim of this study was to characterize the microbiota structure of the pharynx. Pyrosequencing of 16S rRNA gene libraries was used to characterize the pharyngeal microbiota using swab samples from 68 subjects with laryngeal cancer and 28 subjects with vocal cord polyps. Overall, the major phylum was Firmicutes, with Streptococcus as the predominant genus in the pharyngeal communities. Nine core operational taxonomic units detected from Streptococcus, Fusobacterium, Prevotella, Granulicatella, and Veillonella accounted for 21.3% of the total sequences detected. However, there was no difference in bacterial communities in the pharynx from patients with laryngeal cancer and vocal cord polyps. The relative abundance of Firmicutes was inversely correlated with Fusobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes. The correlation was evident at the genus level, and the relative abundance of Streptococcus was inversely associated with Fusobacterium, Leptotrichia, Neisseria, Actinomyces, and Prevotella. This study presented a profile for the overall structure of the microbiota in pharyngeal swab samples. Inverse correlations were found between Streptococcus and other bacterial communities, suggesting that potential antagonism may exist among pharyngeal microbiota.     

Astragaloside IV reversed the autophagy and oxidative stress induced by the intestinal microbiota of AIS in mice

Acute ischaemic stroke (AIS) seriously affects patient quality of life. We explored the role of the intestinal microbiota on oxidative stress and autophagy in stroke, and Astragaloside IV (AS-IV) reversed the changes induced by intestinal microbiota. We determined the characteristics of the intestinal microbiota of AIS and transient ischaemic attack (TIA) patients by 16S sequencing and found that the structure and diversity of the intestinal microbiota in patients with AIS and TIA were significantly different from those in healthy subjects. Specifically, the abundance of genus Bifidobacterium, Megamonas, Blautia, Holdemanella, and Clostridium, content of homocysteine and triglyceride was increased significantly, thus it may be as a potential mechanism of AIS and TIA. Furthermore, germ-free mice were infused intracolonically with fecal supernatants of TIA and AIS with/without feed AS-IV for 12 weeks, and we found that the feces of AIS up-regulated the autophagy markers Beclin-1, light chain 3 (LC3)-II and autophagy-related gene (Atg)12, and the expression of reactive oxygen species (ROS) and NADPH oxidase 2/4 (NOX2/4), malondialdehyde (MDA), however, the expression of total antioxidant capacity (T-AOC) and activity of superoxide dismutase (SOD) and glutathione (GSH) was down-regulated in brain tissue, the content of homocysteine and free fatty acids (FFA) in serum of the mice. Meanwhile, AS-IV could reverse the above phenomenon, however, it does not affect the motor function of mice. AS-IV reversed these changes and it may be a potential drug for AIS therapeutics.     

Tissue localization of aggregation pheromones in the American cockroach, <Emphasis Type="Italic">Periplaneta americana</Emphasis> (Blattodea: Blattidae)

The American cockroach, Periplaneta americana, excretes feces containing aggregation pheromones to attract conspecific individuals. It is thought that these pheromones play an important role in establishing and maintaining colonies. However, despite previous extensive efforts, the aggregation pheromones of P. americana have not been isolated. It is also unclear whether the aggregation pheromones of P. americana are truly biosynthesized by the insect, as most previous experiments extracted chemicals from feces. Here, we investigate the tissue localization of aggregation agents in P. americana. To reduce the effects of diet-derived odorants, we developed a new diet for P. americana consisting of only agar and sugars, and tested the attractiveness of fecal extracts from animals reared on this new diet. Our results show that the aggregation agents of fecal extracts are insect-derived, and the extracts from the midgut evoke stronger behavioral responses than those from other parts of the alimentary tract. This suggests that the midgut may be the production site or the storage organ of the aggregation agents. Thus, our data will facilitate the future identification of the aggregation pheromones of P. americana.     

Effect of <Emphasis Type="Italic">UCP2</Emphasis> and <Emphasis Type="Italic">UCP3</Emphasis> Genes Polymorphisms on Functional Traits in Dairy Cattle

The aim of this study was to investigate associations between genotypes of UCP2 and UCP3 genes, milk, and reproduction traits in dairy cattle. The study included two herds: Jersey cows and Polish Holstein-Friesian (Red and White strain) cows. All cows were genotyped using the PCR-RFLP method and allele frequencies were determined. Statistical analysis showed a significant association between polymorphism in the UCP3 gene and the milk yield and fat content of milk (P ≤ 0.05, P ≤ 0.01) and between the UCP2 gene and the calving interval (P ≤ 0.05). Information contained in this study may be useful in further analysis to define the role of analysed genes in relation to functional traits in dairy cattle, nevertheless, the obtained results should be verified by conducting research on a larger group of animals and various cattle breeds.     

Diversity and dynamics of lactic acid bacteria in <Emphasis Type="Italic">Atole agrio</Emphasis>, a traditional maize-based fermented beverage from South-Eastern Mexico,analysed by high throughput sequencing and culturing

The purpose of this work was to analyse the diversity and dynamics of lactic acid bacteria (LAB) throughout the fermentation process in Atole agrio, a traditional maize based food of Mexican origin. Samples of different fermentation times were analysed using culture-dependent and -independent approaches. Identification of LAB isolates revealed the presence of members of the genera Pediococcus, Weissella, Lactobacillus, Leuconostoc and Lactococcus, and the predominance of Pediococcus pentosaceus and Weissella confusa in liquid and solid batches, respectively. High-throughput sequencing (HTS) of the 16S rRNA gene confirmed the predominance of Lactobacillaceae and Leuconostocaceae at the beginning of the process. In liquid fermentation Acetobacteraceae dominate after 4 h as pH decreased. In contrast, Leuconostocaceae dominated the solid fermentation except at 12 h that were overgrown by Acetobacteraceae. Regarding LAB genera, Lactobacillus dominated the liquid fermentation except at 12 h when Weissella, Lactococcus and Streptococcus were the most abundant. In solid fermentation Weissella predominated all through the process. HTS determined that Lactobacillus plantarum and W. confusa dominated in the liquid and solid batches, respectively. Two oligotypes have been identified for L. plantarum and W. confusa populations, differing in a single nucleotide position each. Only one of the oligotypes was detected among the isolates obtained from each species, the biological significance of which remains unclear.     

Evaluation of the Diversity of Probiotic <Emphasis Type="Italic">Bacillus</Emphasis>, <Emphasis Type="Italic">Clostridium</Emphasis>, and <Emphasis Type="Italic">Bifidobacterium</Emphasis> Using the Illumina-Based Sequencing Method

Bacterial species of Bacillus, Lactobacillus, and Bifidobacterium in the intestinal tract have been used as probiotics. Selections for probiotic candidates by the culture-based approaches are time-consuming and labor-consuming. The aim of this study was to develop a new method based on sequencing strategies to select the probiotic Bacillus, Lactobacillus, and Bifidobacterium. The Illumina-based sequencing strategies with different specific primers for Bacillus, Clostridium, and Bifidobacterium were applied to analyze diversity of the genera in goat feces. The average number of different Bacillus, Clostridium, and Bifidobacterium OTUs (operational taxonomic units) at the 97% similarity level ranged from 1922 to 63172. The coverage index values of Bacillus, Clostridium, and Bifidobacterium calculated from the bacterial OTUs were 0.89, 0.99, and 1.00, respectively. The most genera of Bacillus (37.9%), Clostridium (53%), and Bifidobacterium (99%) were detected in goat feces by the Illumina-based sequencing with the specific primers of the genera, respectively. Higher phylogenetic resolutions of the genera in goat feces were successfully established. The results suggest that the selection for probiotic Bacillus, Clostridium, and Bifidobacterium based on the Illumina sequencing with their specific primers is reliable and feasible, and the core Bacillus, Clostridium, and Bifidobacterium species of healthy goats possess the potentials as probiotic microbial consortia.     

Mouse intestinal microbiota reduction favors local intestinal immunity triggered by antigens displayed in <Emphasis Type="Italic">Bacillus subtilis</Emphasis> biofilm

Background

We previously engineered Bacillus subtilis to express an antigen of interest fused to TasA in a biofilm. B. subtilis has several properties such as sporulation, biofilm formation and probiotic ability that were used for the oral application of recombinant spores harboring Echinococcus granulosus paramyosin and tropomyosin immunogenic peptides that resulted in the elicitation of a specific humoral immune response in a dog model.

Results

In order to advance our understanding of the research in oral immunization practices using recombinant B. subtilis spores, we describe here an affordable animal model. In this study, we show clear evidence indicating that a niche is required for B. subtilis recombinant spores to colonize the densely populated mice intestinal microbiota. The reduction of intestinal microbiota with an antibiotic treatment resulted in a positive elicitation of local humoral immune response in BALB/c mice after oral application of recombinant B. subtilis spores harboring TasA fused to E. granulosus (102-207) EgTrp immunogenic peptide. Our results were supported by a lasting prevalence of spores in mice feces up to 50 days after immunization and by the presence of specific secretory IgA, isolated from feces, against E. granulosus tropomyosin.

Conclusions

The reduction of mouse intestinal microbiota allowed the elicitation of a local humoral immune response in mice after oral application with spores of B. subtilis harboring immunogenic peptides against E. granulosus.

     

Effects of dietary poly-β-hydroxybutyrate (PHB) on microbiota composition and the mTOR signaling pathway in the intestines of <Emphasis Type="Italic">litopenaeus vannamei</Emphasis>

Poly-β-hydroxybutyrate (PHB) is a natural polymer of the short chain fatty acid β-hydroxybutyrate, which acts as a microbial control agent. The mammalian target of the rapamycin (mTOR) signaling pathway plays a crucial role in intestine inflammation and epithelial morphogenesis. In this study, we examined the composition of intestine microbiota, and mTOR signaling-related gene expression in Pacific white shrimp Litopenaeus vannamei fed diets containing different levels of PHB: 0% (Control), 1% (PHB1), 3% (PHB3), and 5% (PHB5) (w/w) for 35 days. High-throughput sequencing analysis revealed that dietary PHB altered the composition and diversity of intestine microbiota, and that the microbiota diversity decreased with the increasing doses of PHB. Specifically, dietary PHB increased the relative abundance of Proteobacteria and Tenericutes in the PHB1 and PHB5 groups, respectively, and increased that of Gammaproteobacteria in the three PHB groups. Alternatively, PHB decreased Alphaproteobacteria in the PHB3 and PHB5 groups. At the genus level, dietary PHB increased the abundance of beneficial bacteria, such as Bacillus, Lactobacillus, Lactococcus, Clostridium, and Bdellovibrio. The relative mRNA expression levels of the mTOR signaling-related genes TOR, 4E-BP, eIF4E1α, and eIF4E2 all increased in the three PHB treatment groups. These results revealed that dietary PHB supplementation had a beneficial effect on intestine health of L. vannamei by modulating the composition of intestine microbiota and activating mTOR signaling.     

Genetic diversity and antimicrobial activity of lactic acid bacteria in the preparation of traditional fermented potato product ‘<Emphasis Type="Italic">tunta’</Emphasis>

Fermentation microorganisms, lactic acid bacteria (LAB) and yeast from 12 samples of tunta production chain were quantified, from the native potatoes used by the process fermentation of potatoes in the river up to the final product. During fermentation, the LAB population steadily increased from 3 to 4 to 8 log CFU/g during the first 8 days in the river and the yeast population increased from 2 to 3 to 3–4 log CFU/g. Overall, 115 LAB strains were isolated using a culture-dependent method. Molecular techniques and 16S rRNA gene sequencing enabled the identification of native species. In LAB isolates, members of the Lactobacillaceae (64%), Leuconostocaceae (9%) and Enterococcaceae (2%) families were identified. The most prevalent LAB species in the tunta production chain was Lactobacillus curvatus, followed by Leuconostoc mesenteroides and Lactobacillus sakei, Lactobacillus brevis and Enterococcus mundtii were also present. Only 13 LAB strains showed anti-listerial activity, and one of them, identified as En. mundtii DSM 4838^T [MG031213], produced antimicrobial compounds that were determined to be proteins after treatment with proteolytic enzymes. Based on these results, we suggest that traditional fermented product-derived LAB strains from specific environments could be selected and used for technological application to control pathogenic bacteria and naturally protect food from post-harvest deleterious microbiota.     

Ethnicity influences gut metabolites and microbiota of the tribes of Assam,India

Introduction

The human gut microbes and their metabolites are involved in multiple host metabolic pathways. Dysbiosis in the gut microbiota and altered metabolite profiles were reported in diseased state. In a region like Assam, where 12.4% of the populations are tribal population, evaluating the influence of ethnicity on gut microbiota and metabolites has become important to further differentiate it from the diseased state.

Objective

To study the influence of ethnicity on fecal metabolite profile and their association with the gut microbiota composition.

Methods

In this study, we determined the untargeted fecal metabolites from five ethnic groups of Assam (Tai-Aiton, Bodo, Karbi, Tea-tribe and Tai-Phake) using GC–MS and compared them among the tribes for common and unique metabolites. Metabolites of microbial origin were related with the available metagenomic data on gut bacterial profiles of the same ethnic groups and functional analysis were carried out based on HMDB.

Results

The core fecal metabolite profile of the Tea-tribe contained aniline, benzoate and acetaldehyde. PLS-DA based on the metabolites suggested that the individuals grouped based on their ethnicity. PCA plot of the data on bacterial abundance at the level of genus indicated clustering of individuals based on ethnicity. Positive correlations were observed between propionic acid and the genus Clostridium (R?=?0.43 and p?=?0.03), butyric acid and the genus Lactobacillus (R?=?0.45 and p?=?0.024), acetic acid and the genus Bacteroides (R?=?0.63 and p?=?0.001) and methane and the genus Escherichia (R?=?0.58 and p?=?0.002).

Conclusion

Results of this study indicated that ethnicity influences both gut bacterial profile and their metabolites.