Quantification of total bacteria, enterobacteria and lactobacilli populations in pig digesta by real-time PCR

Lack of significant effect of gut microbiota on weight gain in newly emerged worker honeybee

The western honeybee, Apis mellifera, harbours a simple and distinct microbiota that has been linked to various positive outcomes for the host. Among these cited benefits is improved weight gain for bees that have been inoculated with their native microbes. This result has been challenged by recent studies which investigated the impact of the gut microbiota on behavioural maturation and associated physiological changes and revealed no effect of the gut microbiota on weight gain. Therefore, we re-examined the role of the microbiota in weight gain by comparing microbiota-deprived bees with those inoculated with gut homogenate or defined communities composed of isolates representing the major bacterial taxa inhabiting the bee gut. We observed no differences in weight gain of adult bees or of their gut tissues across these groups. Further analysis based on nurse/forager cuticular hydrocarbon status and bacterial composition also revealed no significant changes. These results suggest the need for more nuanced investigations aimed at exploring factors such as the conditions in the hive of origin, including larval nutrition.

Influence of Tryptophan Metabolism on the Protective Effect of Weissella paramesenteroides WpK4 in a Murine Model of Chemotherapy-Induced Intestinal Mucositis

Dysbiosis is a notable marker of intestinal mucositis, an inflammatory condition induced by antineoplastic chemotherapy. Scientific evidence supports the effectiveness of probiotics in managing dysbiosis associated with intestinal mucositis. It is known that tryptophan metabolism is a regulatory component in the multifactorial phenomenon of mucosal homeostasis. In the face of that, we aimed to investigate if oral administration of Weissella paramesenteroides WpK4, a probiotic candidate strain, has a protective effect in a murine model of intestinal mucositis induced by 5-fluorouracil (5-FU) and if tryptophan metabolism plays any role in this effect. Gavage with viable cells of W. paramesenteroides WpK4 increased intestinal mucus production, regeneration of villi, as well as control of dysbiosis in mice submitted to 5-FU chemotherapy, and resulted in 100% survival, unlike the control saline-treated group, which resulted in 60% survival of mice after mucositis induction. Weissella paramesenteroides WpK4 genome harbors sequences encoding enzymes for tryptophan production and catabolism and can synthesize tryptophan, tryptamine, and indole acetic acid in vitro. Besides, oral administration of WpK4 induced increased expression of molecules involved in tryptophan metabolism in mouse ileum and serum. Notably, simultaneous treatment with alfa-naphthoflavone, an aryl hydrocarbon receptor (AhR) inhibitor, abolished the protective effects exerted by W. paramesenteroides Wpk4, as manifested by a significant decline in body weight, suggesting that treatment with the probiotic strain modulates AhR activation. Our results suggest that tryptophan metabolism is potentially involved in the protective effects caused by oral administration of W. paramesenteroides WpK4 to mice during gut inflammatory conditions induced by 5-FU.

Traditionally produced tempeh harbors more diverse bacteria with more putative health-promoting properties than industrially produced tempeh

In recent years, there has been a significant shift towards industrialization in food production, resulting in the implementation of higher hygiene standards globally. Our study focused on examining the impact of hygiene standards on tempeh, a popular Rhizopus-based fermented soybean product native to Indonesia, and now famous around the world. We observed that tempeh produced with standardized hygiene measures exhibited a microbiome with comparable bacterial abundances but a markedly different community structure and function than traditionally produced tempeh. In detail, we found a decreased bacterial abundance of lactobacilli and enterobacteria, bacterial diversity, different indicator taxa, and significantly changed community structure in industrial tempeh. A similar picture was found for functional analysis: the quantity of bacterial genes was similar but qualitative changes were found for genes associated with human health. The resistome of tempeh varied based on its microbiome composition. The higher number of antimicrobial resistance genes in tempeh produced without standardized hygiene measures mainly belong to multidrug efflux pumps known to occur in plant-based food. Our findings were confirmed by functional insights into genomes and metagenome-assembled genomes from the dominant bacteria, e.g. Leuconostoc, Limosilactobacillus, Lactobacillus, Enterococcus, Paenibacillus, Azotobacter and Enterobacter. They harboured an impressive spectrum of genes important for human health, e.g. for production of vitamin B1, B7, B12, and K, iron and zinc transport systems and short chain fatty acid production. In conclusion, industrially produced tempeh harbours a less diverse microbiome than the traditional one. Although this ensures production at large scales as well as biosafety, in the long-term it can lead to potential effects for human gut health.

The terroir of Tempeh: Strong region-specific signatures in the bacterial community structures across Indonesia

Tempeh, a soybean product from Indonesia, is created through fermentation by Rhizopus spp. and associated bacteria. Here, we aim to get an overview of the variability of the tempeh microbiota across Indonesia and disentangle influencing factors. We found high variability in bacterial abundance (103 - 109 copies g-1), richness (nASV = 40 - 175 ASVs), and diversity (H' = 0.9 - 3.5) in tempeh. The primary factor affecting this variation was the region, where the tempeh was produced. Interestingly, tempeh samples obtained from geographically close areas tended to share similar bacterial profiles, suggesting a "terroir" of tempeh. Additionally, tempeh wrapped in banana leaves had a higher abundance of enterobacteria in comparison to tempeh wrapped in plastic but also tended to have a higher total bacterial and lactobacilli abundance. Despite all variability, the tempeh core microbiome consists Lactobacillales and Enterobacteriales. This study demonstrates a high variability of bacterial diversity in traditional tempeh from local producers highlighting a strong regional influence across Indonesia.

Microbial Detoxification of Sediments Underpins Persistence of Zostera marina Meadows

Eelgrass meadows have attracted much attention not only for their ability to maintain marine ecosystems as feeding grounds for marine organisms but also for their potential to store atmospheric and dissolved CO2 as blue carbon. This study comprehensively evaluated the bacterial and chemical data obtained from eelgrass sediments of different scales along the Japanese coast to investigate the effect on the acclimatization of eelgrass. Regardless of the eelgrass habitat, approximately 1% Anaerolineales, Babeliales, Cytophagales, and Phycisphaerales was present in the bottom sediment. Sulfate-reducing bacteria (SRB) were present at 3.69% in eelgrass sediment compared to 1.70% in bare sediment. Sulfur-oxidizing bacteria (SOB) were present at 2.81% and 1.10% in the eelgrass and bare sediment, respectively. Bacterial composition analysis and linear discriminant analysis revealed that SOB detoxified H2S in the eelgrass meadows and that the larger-scale eelgrass meadows had a higher diversity of SOB. Our result indicated that there were regional differences in the system that detoxifies H2S in eelgrass meadows, either microbial oxidation mediated by SOB or O2 permeation via the physical diffusion of benthos. However, since bacterial flora and phylogenetic analyses cannot show bias and/or causality due to PCR, future kinetic studies on microbial metabolism are expected.

Ketogenic Diet Induced Shifts in the Gut Microbiome Associate with Changes to Inflammatory Cytokines and Brain-Related miRNAs in Children with Autism Spectrum Disorder

In this interventional pilot study, we investigated the effects of a modified ketogenic diet (KD) on children with autism spectrum disorder (ASD). We previously observed improved behavioral symptoms in this cohort following the KD; this trial was registered with Clinicaltrials.gov (NCT02477904). This report details the alterations observed in the microbiota, inflammation markers, and microRNAs of seven children following a KD for a duration of 4 months. Our analysis included blood and stool samples, collected before and after the KD. After 4 months follow up, we found that the KD led to decreased plasma levels of proinflammatory cytokines (IL-12p70 and IL-1b) and brain-derived neurotrophic factor (BDNF). Additionally, we observed changes in the gut microbiome, increased expression of butyrate kinase in the gut, and altered levels of BDNF-associated miRNAs in the plasma. These cohort findings suggest that the KD may positively influence ASD sociability, as previously observed, by reducing inflammation, reversing gut microbial dysbiosis, and impacting the BDNF pathway related to brain activity.

Mixed probiotics modulated gut microbiota to improve spermatogenesis in bisphenol A-exposed male mice

Bisphenol A (BPA), an environmental endocrine disruptor (EDC), has been implicated in impairing intestinal and male reproductive dysfunction. The efficacy of gut microbiota modulation for BPA-exposed testicular dysfunction has yet to be verified through research. Therefore, this study explored the potential of mixed probiotics in restoring spermatogenesis damage through the gut-testis axis under BPA exposure. We selected two probiotics strains (Lactobacillus rhamnosus and Lactobacillus plantarum) with BPA removal properties in vitro and the BPA-exposed male mice model was established. The probiotics mixture effectively reduced BPA residue in the gut, serum, and testis in mice. Through 16 S rDNA-seq and metabolomics sequencing, we uncovered that vitamin D metabolism and bile acid levels in the gut was abolished under BPA exposure. This perturbation was linked to an increased abundance of Faecalibaculum and decreased abundance of Lachnospiraceae_NK4A136_group and Ligilactobacillus. The probiotics mixture restored this balance, enhancing intestinal barrier function and reducing oxidative stress. This improvement was accompanied by a restored balance of short-chain fatty acids (SCFAs). Remarkably, the probiotics ameliorated testicular dysfunction by repairing structures of seminiferous tubules and reversing arrested spermiogenesis. Further, the probiotics mixture enhanced testosterone-driven increases in spermatogonial stem cells and all stages of sperm cells. Testicular transcriptome profiling linked these improvements to fatty acid degradation and peroxisome pathways. These findings suggest a significant interplay between spermatogenesis and gut microbiota, demonstrating that probiotic intake could be a viable strategy for combating male subfertility issues caused by BPA exposure.

Whole genome sequencing characteristics of Chlamydia psittaci caprine AMK-16 strain, a promising killed whole cell veterinary vaccine candidate against chlamydia infection

Chlamydia psittaci is a primary zoonotic pathogen with a broad host range causing severe respiratory and reproductive system infection in animals and humans. To reduce the global burden of C. psittaci-associated diseases on animal welfare and health and to control the pathogen spread in husbandry, effective vaccines based on promising vaccine candidate(s) are required. Recently, the caprine C. psittaci AMK-16 strain (AMK-16) demonstrated a high level of protection (up to 80-100%) in outbred mice and pregnant rabbits immunized with these formaldehyde-inactivated bacteria against experimental chlamydial wild-type infection. This study investigated the molecular characteristics of AMK-16 by whole-genome sequencing followed by molecular typing, phylogenetic analysis and detection of main immunodominant protein(s) eliciting the immune response in mouse model. Similarly to other C. psittaci, AMK-16 harbored an extrachromosomal plasmid. The whole-genome phylogenetic analysis proved that AMK-16 strain belonging to ST28 clustered with only C. psittaci but not with Chlamydia abortus strains. However, AMK-16 possessed the insert which resulted from the recombination event as the additional single chromosome region of a 23,100 bp size with higher homology to C. abortus (98.38-99.94%) rather than to C. psittaci (92.06-92.55%). At least six of 16 CDSs were absent in AMK-16 plasticity zone and 41 CDSs in other loci compared with the reference C. psittaci 6BC strain. Two SNPs identified in the AMK-16 ompA sequence resulted in MOMP polymorphism followed by the formation of a novel genotype/subtype including three other C. psittaci strains else. AMK-16 MOMP provided marked specific cellular and humoral immune response in 100% of mice immunized with the inactivated AMK-16 bacteria. Both DnaK and GrpE encoded by the recombination region genes were less immunoreactive, inducing only a negligible T-cell murine immune response, while homologous antibodies could be detected in 50% and 30% of immunized mice, respectively. Thus, AMK-16 could be a promising vaccine candidate for the development of a killed whole cell vaccine against chlamydiosis in livestock.

Quantitative whole-tissue 3D imaging reveals bacteria in close association with mouse jejunum mucosa

Because the small intestine (SI) epithelium lacks a thick protective mucus layer, microbes that colonize the thin SI mucosa may exert a substantial effect on the host. For example, bacterial colonization of the human SI may contribute to environmental enteropathy dysfunction (EED) in malnourished children. Thus far, potential bacterial colonization of the mucosal surface of the SI has only been documented in disease states, suggesting mucosal colonization is rare, likely requiring multiple perturbations. Furthermore, conclusive proof of bacterial colonization of the SI mucosal surface is challenging, and the three-dimensional (3D) spatial structure of mucosal colonies remains unknown. Here, we tested whether we could induce dense bacterial association with jejunum mucosa by subjecting mice to a combination of malnutrition and oral co-gavage with a bacterial cocktail (E. coli and Bacteroides spp.) known to induce EED. To visualize these events, we optimized our previously developed whole-tissue 3D imaging tools with third-generation hybridization chain reaction (HCR v3.0) probes. Only in mice that were malnourished and gavaged with the bacterial cocktail did we detect dense bacterial clusters surrounding intestinal villi suggestive of colonization. Furthermore, in these mice we detected villus loss, which may represent one possible consequence that bacterial colonization of the SI mucosa has on the host. Our results suggest that dense bacterial colonization of jejunum mucosa is possible in the presence of multiple perturbations and that whole-tissue 3D imaging tools can enable the study of these rare events.

Microbiota perturbation by anti-microbiota vaccine reduces the colonization of Borrelia afzelii in Ixodes ricinus

BACKGROUND

Ticks can transmit a broad variety of pathogens of medical importance, including Borrelia afzelii, the causative agent of Lyme borreliosis in Europe. Tick microbiota is an important factor modulating, not only vector physiology, but also the vector competence. Anti-microbiota vaccines targeting keystone taxa of tick microbiota can alter tick feeding and modulate the taxonomic and functional profiles of bacterial communities in the vector. However, the impact of anti-microbiota vaccine on tick-borne pathogen development within the vector has not been tested.

RESULTS

Here, we characterized the Ixodes ricinus microbiota modulation in response to B. afzelii infection and found that the pathogen induces changes in the microbiota composition, its beta diversity and structure of bacterial community assembly. Tick microbiota perturbation by anti-microbiota antibodies or addition of novel commensal bacteria into tick midguts causes departures from the B. afzelii-induced modulation of tick microbiota which resulted in a lower load of the pathogen in I. ricinus. Co-occurrence networks allowed the identification of emergent properties of the bacterial communities which better defined the Borrelia infection-refractory states of the tick microbiota.

CONCLUSIONS

These findings suggest that Borrelia is highly sensitive to tick microbiota perturbations and that departure from the modulation induced by the pathogen in the vector microbiota pose a high cost to the spirochete. Network analysis emerges as a suitable tool to identify emergent properties of the vector microbiota associated with infection-refractory states. Anti-microbiota vaccines can be used as a tool for microbiota perturbation and control of important vector-borne pathogens. Video Abstract.

Intermittent fasting positively modulates human gut microbial diversity and ameliorates blood lipid profile

Aim

The aim was to evaluate the impact of intermittent fasting (IF) on human body mass index (BMI) and serum lipid profile thorough constructive rectification of gut microbiota.

Methods and results

Fourteen healthy women and thirty-one men were included in the study. Their blood and fecal samples were collected before and at the end of the study. Blood parameters, anthropometric values, and gut microbiology were noted to investigate the impact of intermittent fasting (IF) on human gut microbiota and physiology. Our data revealed that IF reduces the body weight and improves blood lipid profile, such as increasing high-density lipoprotein (HDL) and decreasing total cholesterol, triglycerides, and low- and very low-density lipoprotein levels. IF also decreases culturable aerobic bacterial count and increased fungal count. It was also found that the gut metagenome is altered considerably after IF. The human fecal bacterial diversity exhibited significant changes in decreased overall bacterial population, increased bacterial diversity (alpha diversity), and promoted evenness within the bacterial population at the species level. Anti-inflammatory bacteria Lactobacillus and Bifidobacterium were favorably increased, while pathogenic bacteria were decreased.

Conclusion

Collectively, these results indicated that IF could improve lipid profile and body weight in humans, and the potential mechanisms might be via regulating gut microbiota.

Significance and impact of the study

We demonstrated for the first time that IF improved body weight and blood lipid profile, indicating that IF could mitigate gut microbiota in humans.

Human supplementation with Pediococcus acidilactici GR-1 decreases heavy metals levels through modifying the gut microbiota and metabolome

Exposure to heavy metals (HMs) is a threat to human health. Although probiotics can detoxify HMs in animals, their effectiveness and mechanism of action in humans have not been studied well. Therefore, we conducted this randomized, double-blind, controlled trial on 152 occupational workers from the metal industry, an at-risk human population, to explore the effectiveness of probiotic yogurt in reducing HM levels. Participants were randomly assigned to two groups: one consumed probiotic yogurt containing the HM-resistant strain Pediococcus acidilactici GR-1 and the other consumed conventional yogurt for 12 weeks. Analysis of metal contents in the blood revealed that the consumption of probiotic yogurt resulted in a higher and faster decrease in copper (34.45%) and nickel (38.34%) levels in the blood than the consumption of conventional yogurt (16.41% and 27.57%, respectively). Metagenomic and metabolomic studies identified a close correlation between gut microbiota (GM) and host metabolism. Significantly enriched members of Blautia and Bifidobacterium correlated positively with the antioxidant capacities of GM and host. Further murine experiments confirmed the essential role of GM and protective effect of GR-1 on the antioxidative role of the intestine against copper. Thus, the use of probiotic yogurt may be an effective and affordable approach for combating toxic metal exposure through the protection of indigenous GM in humans.

ClinicalTrials.gov identifier: ChiCTR2100053222

Limosilactobacillus fermentum JL-3 isolated from "Jiangshui" ameliorates hyperuricemia by degrading uric acid

Recent studies into the beneficial effects of fermented foods have shown that this class of foods are effective in managing hyperuricemia and gout. In this study, the uric acid (UA) degradation ability of Limosilactobacillus fermentum JL-3 strain, isolated from "Jiangshui" (a fermented Chinese food), was investigated. In vitro results showed that JL-3 strain exhibited high degradation capacity and selectivity toward UA. After oral administration to mice for 15 days, JL-3 colonization was continuously detected in the feces of mice. The UA level in urine of mice fed with JL-3 was similar with the control group mice. And the serum UA level of the former was significantly lower (31.3%) than in the control, further confirmed the UA-lowering effect of JL-3 strain. Limosilactobacillus fermentum JL-3 strain also restored some of the inflammatory markers and oxidative stress indicators (IL-1β, MDA, CRE, blood urea nitrogen) related to hyperuricemia, while the gut microbial diversity results showed that JL-3 could regulate gut microbiota dysbiosis caused by hyperuricemia. Therefore, the probiotic Limosilactobacillus fermentum JL-3 strain is effective in lowering UA levels in mice and could be used as a therapeutic adjunct agent in treating hyperuricemia.

Gut microbial indicators of metabolic health underlie age-related differences in obesity and diabetes risk among Native Hawaiians and Pacific Islanders

Native Hawaiians and Pacific Islanders (NHPIs) suffer from higher prevalence of and mortality to type 2 diabetes mellitus (T2DM) than any other major race/ethnic group in Hawaii. Health inequities in this indigenous population was further exacerbated by the SARS-CoV-2 pandemic. T2DM progression and medical complications exacerbated by COVID-19 are partially regulated by the gut microbiome. However, there is limited understanding of the role of gut bacteria in the context of inflammation-related diseases of health disparities including T2DM and obesity. To address these gaps, we used a community-based research approach from a cohort enriched with NHPI residents on the island of Oahu, Hawaii (N=138). Gut microbiome profiling was achieved via 16s rDNA metagenomic sequencing analysis from stool DNA. Gut bacterial capacity for butyrate-kinase (BUK)-mediated fiber metabolism was assessed using quantitative PCR to measure the abundance of BUK DNA and RNA relative to total bacterial load per stool sample. In our cohort, age positively correlated with hemoglobin A1c (%; R=0.39; P<0.001) and body mass index (BMI; R=0.28; P<0.001). The relative abundance of major gut bacterial phyla significantly varied across age groups, including Bacteroidetes (P<0.001), Actinobacteria (P=0.007), and Proteobacteria (P=0.008). A1c was negatively correlated with the relative levels of BUK DNA copy number (R=-0.17; P=0.071) and gene expression (R=-0.33; P=0.003). Interestingly, we identified specific genera of gut bacteria potentially mediating the effects of diet on metabolic health in this cohort. Additionally, α-diversity among gut bacterial genera significantly varied across T2DM and BMI categories. Together, these results provide insight into age-related differences in gut bacteria that may influence T2DM and obesity in NHPIs. Furthermore, we observed overlapping patterns between gut bacteria and T2DM risk factors, indicating more nuanced, interdependent interactions among these factors as partial determinants of health outcomes. This study adds to the paucity of NHPI-specific data to further elucidate the biological characteristics associated with pre-existing health inequities in this racial/ethnic group that is significantly underrepresented in biomedical research.

A Comprehensive Evaluation of Enterobacteriaceae Primer Sets for Analysis of Host-Associated Microbiota

Enterobacteriaceae is one of the most important bacterial groups within the Proteobacteria phylum. This bacterial group includes pathogens, commensal and beneficial populations. Numerous 16S rRNA gene PCR-based assays have been designed to analyze Enterobacteriaceae diversity and relative abundance, and, to the best of our knowledge, 16 primer pairs have been validated, published and used since 2003. Nonetheless, a comprehensive performance analysis of these primer sets has not yet been carried out. This information is of particular importance due to the recent taxonomic restructuration of Enterobacteriaceae into seven bacterial families. To overcome this lack of information, the identified collection of primer pairs (n = 16) was subjected to primer performance analysis using multiple bioinformatics tools. Herein it was revealed that, based on specificity and coverage of the 16S rRNA gene, these 16 primer sets could be divided into different categories: Enterobacterales-, multi-family-, multi-genus- and Enterobacteriaceae-specific primers. These results highlight the impact of taxonomy changes on performance of molecular assays and data interpretation. Moreover, they underline the urgent need to revise and update the molecular tools used for molecular microbial analyses.

Development of a rapid qPCR method to quantify lactic acid bacteria in cold-smoked salmon

Quantification of lactic acid bacteria (LAB) is essential to control quality of seafood products like cold-smoked salmon (CSS). In the present study, we report the design and optimization of a dual-labelled TaqMan ™ probe targeting the V7 region of 16S rRNA gene for the detection of LAB in CSS. This quantitative PCR (qPCR) assays is useful for the simultaneous detection of the ten LAB genera communally encountered in CSS as Aerococcus, Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Macrococcus, Streptococcus, Vagococcus and Weissella. The specificity of this method was demonstrated against 14 genera (44 isolates, 35 species) of Gram-positive bacteria and 19 genera of Gram-negative (40 isolates, 34 species). Calibration of the method was performed in CSS matrix using a mix of equimolar cultured solution of five LAB. Quantification with the qPCR method range from 3.5 to 8.5 Log CFU/g in CSS matrix, covering 5 orders of magnitude. On these artificially contaminated CSS slices, PCR method results correlated successfully (R² = 0.9945) with the conventional enumeration on Elliker medium. In addition, the new method was successful on commercial CSS from five different origins with a quantification range from 3.7 Log CFU/g to 8.0 Log CFU/g. This one-step quantitative methodology is proposed as a rapid and complementary tool of the cultural methods to investigate the LAB microbiota and biodiversity of CSS.

Effect of formulations and fermentation processes on volatile organic compounds and prebiotic potential of gluten-free bread fortified by spirulina (Arthrospira platensis)

Gluten free (GF) foods, designed and marketed for the needs of people who are unable to metabolize gluten, in recent years have aroused growing interest that has led to the conquest of important market segments, with a strongly growing trend. Given the low protein content of standard GF flours, it is particularly important to fortify GF foods, and to study the effect that this process exerts on functional and sensorial characteristics. In this work, fortification of GF bakery goods was done with the addition of Arthrospira platensis (spirulina) flour. Two different dough formulations (with and without fortification) were fermented by four different processes, including spontaneous, single strains and sourdough starters. The baked products were then subjected to "consumer's tests". During the process, fermentation performances, prebiotic activity, and the VOC (Volatile Organic Compound) profiles were analyzed and compared through robust multivariate statistics. The results obtained evidenced that fortification led to a product with more abundant (medium organic acids) and exclusive bioactives (thymol, borneol, and nicotinic acid), which were correlated to the prebiotic activity of spirulina breads. This work, for the first time indicates that spirulina can be used to fortify GF bakery, improving also its functional potential.

Preliminary study on alleviation of heat-induced intestinal inflammation through compensatory effects of glucose oxidase

1. The influence of glucose oxidase (GOD) supplementation on growth, gut inflammation and its compensatory effects in broilers was investigated before and after heat stress.2. Before heat stress, one-day-old broilers were divided into two groups: the control (CON) and GOD (100 g/t complete feed) groups. On d 21, the CON group was equally divided into CON1 and CON2 groups, and heat stress (35°C) was applied to the CON2 and GOD groups for 8 h/day to the end of the study, d 27 of age. The chickens were either killed before heat stress and 2 d after heat stress for the determination of cytokines in the liver and ileum, serum antioxidant enzymes and ileal microbiota. Growth performance was determined before and 7 d after heat stress.3. The GOD decreased Clostridiales and Enterobacteriaceae families of bacteria and increased ileal nuclear factor-κB, interleukin-1β, and interferon-γ (P < 0.05) before heat stress. The broilers exhibited compensatory effects, including increases in ileal sirtuin-1, heat shock protein 70 expression, liver nuclear factor erythroid 2-related factor 2 content, serum total antioxidant capacity and glutathione peroxidase level (P < 0.05). At 2 d after heat stress, inflammatory factors were increased in both the CON2 and GOD groups, but the levels were lower in the GOD than CON2 (P < 0.05). On d 7 after heat stress, GOS alleviated heat stress induced growth retardation (P < 0.05).4. These data suggested that GOD supplementation in broiler diets before heat stress stimulated intestinal oxidative stress and produced a compensatory response, which prevented a rapid increase in intestinal inflammatory factors and helped to maintain growth performance under heat stress.

Lactobacillus plantarum and Lactobacillus reuteri as Functional Feed Additives to Prevent Diarrhoea in Weaned Piglets

Simple Summary

Antimicrobial resistance is an increasing global concern. Effective alternatives that could replace and reduce antimicrobial treatments in farming have therefore become crucial for animal, human and environmental health. In swine farming, weaning is a stressful phase where piglets can develop multifactorial enteric disorders that require antibiotic treatments. Functional nutrition could thus represent a valuable alternative to reduce and tackle antibiotic resistance. This study assesses the effects of Lactobacillus plantarum and Lactobacillus reuteri on in-feed supplementation in weaned piglets. After weaning, piglets were allotted to four experimental groups fed a basal diet (CTRL) and a basal diet supplemented with 2 × 10⁸ CFU/g of L. plantarum (PLA), L. reuteri and a combination of the two strains (P+R) for 28 days. Zootechnical performance and diarrhoea occurrence were recorded. Microbiological and serum metabolism analyses of faeces and blood samples were performed. Supplemented groups with lactobacilli showed a lower occurrence of diarrhoea and improved faecal consistency compared to the control. The PLA group registered the lowest diarrhoea frequency during the 28-day experimental period. The results suggest that dietary administration of L. plantarum and L. reuteri could prevent the occurrence of diarrhoea in weaned piglets.

Abstract

The effects of Lactobacillus plantarum and Lactobacillus reuteri and their combination were assessed in weaned piglets. Three hundred and fifty weaned piglets (Landrace × Large White), balanced in terms of weight and sex, were randomly allotted to four experimental groups (25 pens, 14 piglets/pen). Piglets were fed a basal control diet (CTRL, six pens) and a treatment diet supplemented with 2 × 10⁸ CFU/g of L. plantarum (PLA, 6 pens), 2 × 10⁸ CFU/g L. reuteri (REU, six pens) and the combination of both bacterial strains (1 × 10⁸ CFU/g of L. plantarum combined with 1 × 10⁸ CFU/g of L. reuteri, P+R, 7 pens) for 28 days. Body weight and feed intake were recorded weekly. Diarrhoea occurrence was assessed weekly by the faecal score (0–3; considering diarrhoea ≥ 2). At 0 and 28 days, faecal samples were obtained from four piglets per pen for microbiological analyses and serum samples were collected from two piglets per pen for serum metabolic profiling. Treatments significantly reduced diarrhoea occurrence and decreased the average faecal score (0.94 ± 0.08 CTRL, 0.31 ± 0.08 PLA, 0.45 ± 0.08 REU, 0.27 ± 0.08 P+R; p < 0.05). The PLA group registered the lowest number of diarrhoea cases compared to other groups (20 cases CTRL, 5 cases PLA, 8 cases REU, 10 cases P+R; p < 0.01). After 28 days, the globulin serum level increased in PLA compared to the other groups (24.91 ± 1.09 g/L CTRL, 28.89 ± 1.03 g/L PLA, 25.91 ± 1.03 g/L REU, 25.31 ± 1.03 g/L P+R; p < 0.05). L. plantarum and L. reuteri could thus be considered as interesting functional additives to prevent diarrhoea occurrence in weaned piglets.

Evaluation of Tannin Extracts, Leonardite and Tributyrin Supplementation on Diarrhoea Incidence and Gut Microbiota of Weaned Piglets

The effects of the dietary administration of a combination of Quebracho and Chestnut tannins, leonardite and tributyrin were evaluated in weaned piglets. A total of 168 weaned piglets (Landrace × Large White) were randomly allotted to two experimental groups (6 pens/group, 14 piglets/pen). Animals were fed a basal control diet (CTRL) and a treatment diet (MIX) supplemented with 0.75% tannin extracts, 0.25% leonardite and 0.20% tributyrin for 28 days. Individual body weight and feed intake were recorded weekly. Diarrhoea incidence was recorded by a faecal scoring scale (0-3; considering diarrhoea ≥ 2). At 0 and 28 days, faecal samples were obtained from four piglets/pen for microbiological and chemical analyses of faecal microbiota, which were then assessed by V3-V4 region amplification sequencing. At 28 days, blood from two piglets/pen was sampled to evaluate the serum metabolic profile. After 28 days, a reduction in diarrhoea incidence was observed in the MIX compared to CTRL group (p < 0.05). In addition, compared to CTRL, MIX showed a higher lactobacilli:coliform ratio and increased Prevotella and Fibrobacter genera presence (p < 0.01). The serum metabolic profile showed a decreased level of low-density lipoproteins in the treated group (p < 0.05). In conclusion, a combination of tannin extract, leonardite and tributyrin could decrease diarrhoea incidence and modulate the gut microbiota.

Volatilome changes during probiotic fermentation of combined soy and rice drinks

Plant-based drinks as a substitute for animal milk consumption are crucial products in the food industry. Soy and rice drinks are the most successful milk substitutes but are low in fiber and protein contents, respectively, whilst being rich in sugars. Generally, an improvement is foreseen; thus, apart from supplement addition, a natural occurring strategy is functionalizing the drinks by beneficial bacteria fermentation. The aim of this work is to develop novel plant-based drinks assessing different mixtures of soy and rice milks fermented with single or multi-strain probiotics (Lactobacillus fermentum, L. plantarum, L. helveticus, Bifidobacterium bifidum, and B. longum). The drinks were characterized to study bacterial performances, by means of culture-dependent and -independent techniques, and their volatilome, by means of solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis. Through multivariate analysis, these features were investigated and correlated to define accurate descriptors of the produced functional drinks. The results showed that combined drinks and multi-strain fermentation generated higher-value products. For example, combined drinks in comparison with single ones had a lower amount of toxic 2-acetyl-3,5-dimethylfuran and higher abundances of desirable compounds such as 2-butanone, 3-hydroxy and butanoic acid. Multivariate analysis of volatile metabolites and physiological parameters could offer a novel approach to assess the quality of functional plant-based drinks and result in a decisional tool for industrial applications.

Neonicotinoids in the agroecosystem: In-field long-term assessment on honeybee colony strength and microbiome

Bees can be severely affected by various plant protection products (PPP). Among these, neonicotinoid insecticides are of concern as they have been shown to be responsible for extensive honeybee colonies death when released into the environment. Also, sublethal neonicotinoid doses contaminating single honeybees and their colonies (e.g. through contaminated pollen) are responsible for honeybees physiological alterations with probable implication also on microbiome functionality. Honeybees show symbiotic interactions with specific gut bacteria that can enhance the adult host performances. Among the known mechanisms, the modulation of the immune system, the degradation of recalcitrant secondary plant metabolites, pollen digestion, and hormonal signaling, are the most important functional benefits for the host honeybee. To date, few research efforts have aimed at revealing the impact of PPP on the gut microbial community of managed and wild honeybees. The majority of the existing literature relays on cage or semifield tests of short duration for research investigating neonicotinoids-gut microbiome interactions. This research wanted to unravel the impact of two neonicotinoids (i.e. imidacloprid and thiacloprid) in natural field conditions up to 5 weeks of exposure. A long-term impact of neonicotinoids on gut microbial community of honeybees was observed. The alterations affected several microbial genera and species such as Frischella spp., lactobacilli and bifidobacteria, whose shifting is implicated in intestinal dysbiosis. Long-term impact leading to dysbiosis was detected in case of exposure to imidacloprid, whereas thiacloprid exposure stimulated temporary dysbiosis. Moreover, the microbial diversity was significantly reduced in neonicotinoid-treated groups. Overall, the reported results support a compromised functionality of the gut microbial community, that might reflect a lower efficiency in the ecosystemic functionality of honeybees.

Evaluation the effect of subchronic feeding of transgenic cotton line (CKC1) on the faecal microbiota of albino rabbits

Recent studies have demonstrated a strong relationship between the intestinal microbiota and the host health. As such, consumers are increasingly becoming more concerned about the potential effect of certain foods/feeds, particularly of transgenic origin on the gut microbiota. Although the European Food Safety Authority has recommended in their guidelines, to study the effect of transgenic food/feed on host-microbiota, yet, few studies have focused on the evaluation of such effects mainly due to culturing difficulties. Therefore, this study was intended to evaluate the potential adverse effects of transgenic diet consumption on some specific gut microflora (Lactobacillus group, Bifidobacterium genus, Escherichia coli subgroup and Enterococcus genus) of rabbits. A total of forty-eight rabbits were randomly assigned into four groups and fed a diet containing a variable proportion of transgenic cottonseeds at 0, 20, 30 and 40% inclusion level, respectively. Changes in the specific or total faecal bacterial population were monitored at five different experimental stages (i.e. 0, 45, 90, 135 and 180 days) using both the traditional plate count method (TM) and quantitative real-time PCR (qPCR). No significant differences (p > .05) were observed concerning numbers of specific bacteria or total bacteria between the control and experimental groups, though qPCR showed numerically higher values in terms of 16S rRNA gene copies as compared to the values obtained from TM. However, such numerical differences were biologically insignificant (p > .05). Similarly, no significant variations were noticed in the calculated B/E (log₁₀ copies of Bifidobacterium per g faces/log10 copies of E. coli genome per g faeces) ratios in all the groups. All the ratios were in the range of 1.24 to 1.30 throughout the experiment, indicating a good balance of intestinal microflora and greater resistance to intestinal disorders. It is therefore concluded that feeding transgenic cottonseeds could not adversely affect the gut microflora of rabbits during a long-term study.

Dietary nucleotide supplementation as an alternative to in-feed antibiotics in weaned piglets

Nucleotides are important to cell growth and division and are crucial to the rapid proliferation of such cells as the intestinal mucosa and immune cells. Accordingly, the nucleotide requirements of animals are high during periods of rapid growth and periods of stress like post-weaning period. Thus, nucleotide supplementation may be a possible alternative to in-feed antibiotics as growth promoter in this phase. The study aimed to evaluate dietary nucleotide supplementation as an alternative to in-feed antibiotics on performance and gut health of weaned piglets. Ninety-six 21-day-old piglets, weighing 7.44 ± 0.65 kg, were allocated into 1 of 3 treatments (8 pens per treatment; 4 pigs per pen) in a 14-day trial. Dietary treatments consisted of control: corn-soybean meal-based diet; nucleotides: control +2 g/kg of a nutritional additive with purified nucleotides; and antibiotic: control +0.8 g/kg of antibiotic growth promoter based on colistin and tylosin. Performance variables and fecal score were not affected (P > 0.05) by supplementing nucleotide or antibiotic. Nucleotides treatment had similar effect to antibiotic and superior to control (P < 0.05) on enhancing duodenum villus height, jejunum crypt depth, and reduction of Paneth cellular area. Duodenum and ileum of animals supplemented with nucleotides or antibiotics had higher (P < 0.05) number of proliferating cells than did those of control animals, whereas the jejunum of animals that received antibiotic diets presented more (P < 0.05) proliferating cells than either the nucleotides or control animals. Jejunum of nucleotide-treated piglets showed a greater number of apoptotic cells than those fed antibiotic or control diets (P < 0.05). Nucleotides and antibiotic treatments decreased the B lymphocyte counts in duodenum and ileum (P < 0.05) but increased in the jejunum (P < 0.05), when compared to the control treatment. Relative abundance of mitogen-activated protein kinases-6, haptoglobin, and tumor necrosis factor-α mRNA was not influenced (P > 0.05) by treatments. In the ileal, antibiotic supplementation reduced total bacteria quantification compared to nucleotide supplementation or the control (P < 0.05), whereas nucleotides supplementation increased enterobacteria proliferation compared to the antibiotic or control diets (P < 0.05). However, nucleotides and antibiotic reduced (P < 0.05) colon total bacteria quantification when compared to control. These results suggest that the nucleotides source used to weaned piglets improved gut health by modulating the local immune response and modulating intestinal mucosa development, and, therefore, nucleotides may be an alternative to antibiotics as growth promoters.

Understanding GroEL and DnaK Stress Response Proteins as Antigens for Bacterial Diseases

Bacteria do not simply express a constitutive panel of proteins but they instead undergo dynamic changes in their protein repertoire in response to changes in nutritional status and when exposed to different environments. These differentially expressed proteins may be suitable to use for vaccine antigens if they are virulence factors. Immediately upon entry into the host organism, bacteria are exposed to a different environment, which includes changes in temperature, osmotic pressure, pH, etc. Even when an organism has already penetrated the blood or lymphatics and it then enters another organ or a cell, it can respond to these new conditions by increasing the expression of virulence factors to aid in bacterial adherence, invasion, or immune evasion. Stress response proteins such as heat shock proteins and chaperones are some of the proteins that undergo changes in levels of expression and/or changes in cellular localization from the cytosol to the cell surface or the secretome, making them potential immunogens for vaccine development. Herein we highlight literature showing that intracellular chaperone proteins GroEL and DnaK, which were originally identified as playing a role in protein folding, are relocated to the cell surface or are secreted during invasion and therefore may be recognized by the host immune system as antigens. In addition, we highlight literature showcasing the immunomodulation effects these proteins can have on the immune system, also making them potential adjuvants or immunotherapeutics.

Association Between Tail-Biting and Intestinal Microbiota Composition in Pigs

Tail-biting (TB) in pigs is a serious behavioral disorder. It is an important challenge in swine production as it impacts animal welfare and health and the economics and safety of the pork meat supply chain. To prevent TB, approaches including enrichment material and tail docking are proposed but none are optimal. Nutrition appears to be an important factor in TB behavior, perhaps by modulating the intestinal microbiota (IM). Our aim was to assess the association between TB behavior and IM in pigs through comparisons of IM in groups of biter, bitten and non-biter/non-bitten pigs. Each group composed of 12 pigs was formed at the beginning of the growing/finishing phase based on a target behavior analysis centered on TB behavior for the biter group and a score of damages caused to the tail for the bitten group. Blood and fecal samples were collected from each pig during a TB episode, at time 0, t0, and when the TB episode was considered finished, 4 weeks later, at time 1, t1. Serum cortisol level was determined by ELISA and used as an indicator of stress. The pig's fecal microbiota was analyzed from DNA extracted from freshly collected fecal matter using amplicon sequencing of the V4 hypervariable region of the 16S rRNA gene. Serum cortisol levels were significantly higher in either the biter or bitten pig groups compared to the negative control group (p = 0.02 and p = 0.01, respectively). The microbiota alpha-diversity was not significantly different between all groups, biter, bitten and negative control. Analyses of beta-diversity, however, revealed a significant difference between either the biter or the bitten group in comparison to the non-biter/non-bitten negative control group in terms of structure and composition of the microbiota. Lactobacillus were significantly more abundant in the negative control group compared to the two other groups (p = 0.001). No significant difference was revealed between the biter and bitten groups. Quantitative real-time PCR (qPCR) confirmed that lactobacilli were more abundant in the negative control group. Our study indicates that TB behavior is associated with the IM composition in pigs.

Anti-Tick Microbiota Vaccine Impacts Ixodes ricinus Performance during Feeding

The tick microbiota is a highly complex ensemble of interacting microorganisms. Keystone taxa, with a central role in the microbial networks, support the stability and fitness of the microbial communities. The keystoneness of taxa in the tick microbiota can be inferred from microbial co-occurrence networks. Microbes with high centrality indexes are highly connected with other taxa of the microbiota and are expected to provide important resources to the microbial community and/or the tick. We reasoned that disturbance of vector microbiota by removal of ubiquitous and abundant keystone bacteria may disrupt the tick-microbiota homeostasis causing harm to the tick host. These observations and reasoning prompted us to test the hypothesis that antibodies targeting keystone bacteria may harm the ticks during feeding on immunized hosts. To this aim, in silico analyses were conducted to identify keystone bacteria in the microbiota of Ixodes nymphs. The family Enterobacteriaceae was among the top keystone taxa identified in Ixodes microbiota. Immunization of α-1,3-galactosyltransferase-deficient-C57BL/6 (α1,3GT KO) mice with a live vaccine containing the Enterobacteriaceae bacterium Escherichia coli strain BL21 revealed that the production of anti-E. coli and anti-α-Gal IgM and IgG was associated with high mortality of I. ricinus nymphs during feeding. However, this effect was absent in two different strains of wild type mice, BALB/c and C57BL/6. This result concurred with a wide distribution of α-1,3-galactosyltransferase genes, and possibly α-Gal, in Enterobacteriaceae and other bacteria of tick microbiota. Interestingly, the weight of I. ricinus nymphs that fed on E. coli-immunized C57BL/6 was significantly higher than the weight of ticks that fed on C57BL/6 immunized with a mock vaccine. Our results suggest that anti-tick microbiota vaccines are a promising tool for the experimental manipulation of vector microbiota, and potentially the control of ticks and tick-borne pathogens.

Comparing the Effectiveness of Three Different Biorefinery Processes at Recovering Bioactive Products from Hemp (Cannabis sativa L.) Byproduct

Hemp (Cannabis sativa L.) seeds are considered a nutritional powerhouse, rich in proteins and unsaturated fatty acids. The market for hemp seed food products is growing, due to the loosening of constraints in industrial cultivation. During the food processing chain, the external part of the seed is discarded, although it contains a significant amount of proteins. Converting this material into value-added products with a biorefinery approach could meet the ever-increasing need for sustainable protein sources while reducing food waste. In this study, creating value from hemp byproducts was pursued with three different approaches: (i) chemical extraction followed by enzymatic digestion, (ii) liquid fermentation by strains of Lactobacillus spp., and (iii) solid-state fermentation by Pleurotus ostreatus. The resulting products exhibited a range of in vitro antioxidant and antihypertensive activity, depending on the proteases used for enzymatic digestion, the bacterial strain, and the length of time of the two fermentation processes. These byproducts could be exploited as functional ingredients in the food, pharmaceutical, and cosmetic industries; the suggested biorefinery processes thus represent potential solutions for the development of other protein-containing byproducts or wastes.

Eucommia ulmoides Flavones as Potential Alternatives to Antibiotic Growth Promoters in a Low-Protein Diet Improve Growth Performance and Intestinal Health in Weaning Piglets

Eucommia ulmoides flavones (EUF) have been demonstrated to attenuate the inflammation and oxidative stress of piglets. This study aimed to test whether EUF could be used as an alternative antibiotic growth promoter to support growth performance and maintain intestinal health in weanling piglets. Weaned piglets (n = 480) were assigned into three groups and fed with a low-protein basal diet (NC), or supplementation with antibiotics (PC) or 0.01% EUF (EUF). Blood, intestinal contents, and intestine were collected on days 15 and 35 after weaning. The results showed the PC and EUF supplementations increased (p < 0.05) body weight on day 35, average daily gain and gain: feed ratio from day 15 to day 35 and day 0 to day 35, whereas decreased (p < 0.05) the diarrhea index of weanling piglets. EUF treatment increased (p < 0.05) jejunal villus height: crypt depth ratio, jejunal and ileal villus height, and population of ileal lactic acid bacteria on day 15 but decreased (p < 0.05) the population of ileal coliform bacteria on day 15 and day 35. These findings indicated the EUF, as the potential alternative to in-feed antibiotic growth promoter, could improve growth performance and intestinal morphology, and decrease colonization of coliform bacteria and diarrhea index in weanling piglets.

Salmonella enterica Serovar Typhimurium Temporally Modulates the Enteric Microbiota and Host Responses To Overcome Colonization Resistance in Swine

Salmonella enterica serovar Typhimurium is a prevalent incitant of enteritis in human beings and nonhuman animals. It has been proposed that host defense responses incited by Salmonella allow the bacterium to overcome colonization resistance. Piglets (n = 24) were orally inoculated with S. enterica serovar Typhimurium DT104 or buffer alone, and the host and microbial responses were temporally examined at the acute (2 days postinoculation [dpi]), subacute (6 dpi), and recovery (10 dpi) stages of salmonellosis. At the acute stage of disease, body temperatures were elevated, and feed consumption and weight gain were reduced. The densities of Salmonella associated with the gut mucosa decreased over time, with higher densities of the bacterium in the ileum and the large intestine. Moreover, substantive histopathological changes were observed as a function of time, with prominent epithelial injury and neutrophil infiltration observed at 2 dpi. Correspondingly, a variety of host metrics were temporally affected in piglets with salmonellosis (e.g., TNFα, IFNγ, PR39, βD2, iNOS, IL8, REGIIIγ). The enteric microbiota was characterized using culture-independent and -dependent methods in concert, and taxon- and location-specific changes to the microbiota were observed in infected piglets. Bacteroides spp. (e.g., Bacteroides uniformis, Bacteroides fragilis), Streptococcus spp. (e.g., Streptococcus gallolyticus), and various Gammaproteobacteria were highly associated with inflamed tissues, while bacteria within the Ruminococcaceae and Veillonellaceae families were mainly associated with healthy mucosae. In conclusion, the study findings showed that S Typhimurium incited temporal and spatial modifications to the swine autochthonous microbiota, and to host defense responses, that were consistent with overcoming colonization resistance to incite salmonellosis in swine.IMPORTANCE Limited information is available on host and enteric microbiota responses incited by Salmonella enterica serovar Typhimurium in swine and on possible mechanisms by which the bacterium overcomes colonization resistance to incite salmonellosis. Temporal characterization of a variety of host metrics in piglets (e.g., physiological, histopathological, and immunological) showed the importance of studying the progression of salmonellosis. A number of host responses integrally associated with disease development were identified. Utilization of next-generation sequence analysis to characterize the enteric microbiota was found to lack sufficient resolution; however, culture-dependent and -independent methods in combination identified taxon- and location-specific changes to bacterial communities in infected piglets. The study identified bacterial and host responses associated with salmonellosis, which will be beneficial in understanding colonization resistance and in the development of effective alternatives to antibiotics to mitigate salmonellosis.

Short Communication: Circulating Mitochondrial DNA and Lipopolysaccharide-Binding Protein but Not Bacterial DNA Are Increased in Acute Human Immunodeficiency Virus Infection

Microbial translocation has been suggested as a major driver of chronic immune activation HIV infection. Thus, we compared the extent of microbial translocation in patients with acute HIV infection and patients followed after CD4-guided structured treatment interruption (STI) by measuring different circulating markers: (1) lipopolysaccharide (LPS)-binding protein (LBP), (2) bacterial DNA, (3) soluble CD14 (sCD14), and (4) mitochondrial DNA (mtDNA). Bacterial DNA and sCD14 levels were similar in all groups. Patients in acute phase showed higher levels of LBP and mtDNA. In STI, we found a positive correlation between the percentage of CD8+ T cells and bacterial DNA levels. Considering all patients, LBP was positively correlated with the percentage and the absolute count of CD8+ T cells, and with mtDNA stressing the importance of mitochondrial products in sustaining chronic immune activation.

A comparison and evaluation of the effects of biochar on the anaerobic digestion of excess and anaerobic sludge

The mechanisms and enhancing effects of different biochar loadings on the digesters receiving low and high excess (or anaerobic) sludge loadings were thoroughly examined in the present study. This was done to explore an efficient method for converting excess sludge to anaerobic sludge. Biochar had an obvious effect on the anaerobic digestion of excess sludge but not on the anaerobic sludge. When the amount of biochar added was equivalent to 100% of the sludge TS, the cumulative methane yields of anaerobic digestion inoculated with small and large amounts of excess sludge were respectively 30.2 and 1.7 times that of those without biochar. The number of methanogens in the digesters that received small and large inoculations of excess sludge with 100% biochar, were respectively 105.4% and 20.6% higher than those without biochar. The biochar enhanced the systems performance because it selectively enriched the Trichococcus and Methanomicrobiales tightly attach to it. This enhanced the synergy and overall activity of the system by promoting biofilm development. Ultimately, the integration of 100% biochar and excess sludge can be used as a substitute for anaerobic sludge as an inoculum by giving similar overall performance.

Effect of Alliaceae Extract Supplementation on Performance and Intestinal Microbiota of Growing-Finishing Pig

Simple Summary

The increasing interest in phytogenics for use with livestock, especially swine and poultry, is mainly due to their antimicrobial, antioxidant, growth-promoting, and gut microbiome modulation properties, which makes them ideal candidates to mitigate the negative effects of the ban on antibiotic growth promoters in the European Union. We tested the ability of Allium spp. extract (containing garlic and onion), one of the best-known phytogenics, used in pig feed, to improve growth performance through modulation of the microbiome and changes in the metabolism of short-chain fatty acids in the gut tract. The promising results obtained in the present study suggested that Allium spp. extracts had the potential to be used in feeding pigs to improve growth performances by modulating the microbiota and metabolism of short-chain fatty acids.

Abstract

The aim of the present study was to ascertain whether an Allium spp. extract rich in organosulfur compounds, such as propyl thiosulfonate (PTSO), added to the feed of growing-finishing pigs at 5 g/kg enhances growth performance or affects the fecal microbiome, the levels of short-chain fatty acids, or the antioxidant capacity of the animals. Fifty male growing pigs (large white) of 23.07 ± 2.87 kg average body weight were randomly allotted to two treatments in a 103-day trial. The trial was divided into two periods, an initial growing phase (56-days) and a finishing phase (47-days). Two dietary treatments for each phase (growing and finishing) were used: a control diet (CON) and an experimental diet consisting of the control diet to which 5 g/kg of Allium spp. extract was added to substitute sepiolite (GAR). Throughout the study, body weight, average daily gain (kg/day, ADG), feed intake (kg/day), and feed conversion ratio (kg/kg) were measured, while the backfat thickness and muscle depth were determined at the end of the study. Besides, feces samples were taken for bacterial counts by means of real-time PCR and short-chain fatty acid (SCFA) profile determination, and the antioxidant capacity was assessed in serum and saliva. In the animals receiving Allium spp. extract (5 g/kg) in the feed, ADG increased (p < 0.05) throughout the trial, Salmonella spp. and Clostridium spp. counts in feces had decreased (p < 0.05) when measured on day 56, and, by day 103, Salmonella spp., Clostridium spp., and Enterobacteriaceae counts had decreased (p < 0.05) and Lactobacillus spp. counts had increased (p < 0.01) in feces. Regarding the SCFA profile in feces and antioxidant capacity measured in serum and saliva, supplementation with Allium spp. extract significantly increased the levels of propionic, isobutyric, and isovaleric acids and the percentage of total branched fatty acids, while the c2/c3 and (c2 + c4)/c3 ratios were lower (p < 0.05) in feces; the Trolox equivalent antioxidant capacity and the cupric reducing antioxidant capacity levels in serum were significantly higher in the same pigs on day 103 than on day 0. Consequently, based on the current results, Allium spp. extract rich in organosulfur compounds, added to the diet at 5 g/kg, had a beneficial effect on the microbiota and would seem to be a possible alternative for increasing the growth performance of growing-finishing pigs. However, further studies on the effects of Allium spp. supplementation on carcass quality are necessary.

Characterizing the postmortem human bone microbiome from surface-decomposed remains

Microbial colonization of bone is an important mechanism of postmortem skeletal degradation. However, the types and distributions of bone and tooth colonizing microbes are not well characterized. It is unknown if microbial communities vary in abundance or composition between bone element types, which could help explain differences in human DNA preservation. The goals of the present study were to (1) identify the types of microbes capable of colonizing different human bone types and (2) relate microbial abundances, diversity, and community composition to bone type and human DNA preservation. DNA extracts from 165 bone and tooth samples from three skeletonized individuals were assessed for bacterial loading and microbial community composition and structure. Random forest models were applied to predict operational taxonomic units (OTUs) associated with human DNA concentration. Dominant bacterial bone colonizers were from the phyla Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, and Planctomycetes. Eukaryotic bone colonizers were from Ascomycota, Apicomplexa, Annelida, Basidiomycota, and Ciliophora. Bacterial loading was not a significant predictor of human DNA concentration in two out of three individuals. Random forest models were minimally successful in identifying microbes related to human DNA concentration, which were complicated by high variability in community structure between individuals and body regions. This work expands on our understanding of the types of microbes capable of colonizing the postmortem human skeleton and potentially contributing to human skeletal DNA degradation.

Microbial Fermentation of Industrial Rice-Starch Byproduct as Valuable Source of Peptide Fractions with Health-Related Activity

The rice-starch processing industry produces large amounts of a protein-rich byproducts during the conversion of broken rice to powder and crystal starch. Given the poor protein solubility, this material is currently discarded or used as animal feed. To fully exploit rice's nutritional properties and reduce this waste, a biotechnological approach was adopted, inducing fermentation with selected microorganisms capable of converting the substrate into peptide fractions with health-related bioactivity. Lactic acid bacteria were preferred to other microorganisms for their safety, efficient proteolytic system, and adaptability to different environments. Peptide fractions with different molecular weight ranges were recovered from the fermented substrate by means of cross-flow membrane filtration. The fractions displayed in vitro antioxidant, antihypertensive, and anti-tyrosinase activities as well as cell-based anti-inflammatory and anti-aging effects. In the future, the peptide fractions isolated from this rice byproduct could be directly exploited as health-promoting functional foods, dietary supplements, and pharmaceutical preparations. The suggested biotechnological process harnessing microbial bioconversion may represent a potential solution for many different protein-containing substrates currently treated as byproducts (or worse, waste) by the food industry.

Tibet plateau probiotic mitigates chromate toxicity in mice by alleviating oxidative stress in gut microbiota

Heavy metal contamination in food endangers human health. Probiotics can protect animals and human against heavy metals, but the detoxification mechanism has not been fully clarified. Here, mice were supplemented with Pediococcus acidilactici strain BT36 isolated from Tibetan plateau yogurt, with strong antioxidant activity but no chromate reduction ability for 20 days to ensure gut colonization. Strain BT36 decreased chromate accumulation, reduced oxidative stress, and attenuated histological damage in the liver of mice. 16S rRNA and metatranscriptome sequencing analysis of fecal microbiota showed that BT36 reversed Cr(VI)-induced changes in gut microbial composition and metabolic activity. Specifically, BT36 recovered the expressions of 788 genes, including 34 inherent Cr remediation-relevant genes. Functional analysis of 10 unannotated genes regulated by BT36 suggested the existence of a new Cr(VI)-reduction gene in the gut microbiota. Thus, BT36 can modulate the gut microbiota in response to Cr(VI) induced oxidative stress and protect against Cr toxicity.

Reducing residual antibiotic levels in animal feces using intestinal Escherichia coli with surface-displayed erythromycin esterase

Antibiotics are widely used in livestock and poultry industries, which results in large quantities of antibiotic residues in manure that influences subsequent treatments. In this study, an Escherichia coli strain was engineered to display erythromycin esterase on its cell surface. The engineered strain (E. coli ereA) efficiently degraded erythromycin by opening the macrocyclic 14-membered lactone ring in solution. Erythromycin (50 mg/L) was completely degraded in a solution by E. coli ereA (1 × 10⁹ CFU/mL) within 24 h. E. coli ereA retained over 86.7 % of the initial enzyme activity after 40 days of storage at 25 °C, and 78.5 % of the initial activity after seven repeated batch reactions in solution at 25 °C. Mice were fed with E. coli ereA and real-time quantitative PCR data showed that E. coli ereA colonized in the mice large intestine. The mice group fed E. coli ereA exhibited 83.13 % decrease in erythromycin levels in their feces compared with the mice group not fed E. coli ereA. E. coli ereA eliminated antibiotics from the source preventing its release into the environment. The surface-engineered strain therefore is an effective alternative agent for treating recalcitrant antibiotics, and has the potential to be applied in livestock and poultry industries.

Shift of Volatile Organic Compounds (VOCs) in Gluten-Free Hemp-Enriched Sourdough Bread: A Metabolomic Approach

Hemp seed flour represents a potential ingredient for protein enrichment of gluten-free bakery products, the nutritional value of which could be further increased by fermentation with sourdough or with beneficial lactic acid bacteria strains. In this study, a metabolomic approach was used to evaluate the effect of hemp seed flour addition and sourdough fermentation on the production of flavoring and health-related volatile organic compounds (VOCs) in a gluten-free bread. Multivariate analysis of VOCs provided an in-depth description of the effects of hemp seed flour addition and sourdough fermentation on flavoring and bioactive compounds. In particular, an increased concentration of antimicrobial compounds, a larger spectrum of bioactive VOCs and a typical flavoring profile was evidenced in comparison to standard products. Furthermore, an increase of fermentation metabolites was observed in comparison to a standard dough, relating to abundances of 2-butanone-3-hydroxy, acetic acid, ethanol, and 1,4-butanediol. This study provides new insights on the evolution of flavoring and bioactive hemp seed flour constituents during sourdough fermentation, evidencing their retention in baked goods, and describes a new approach that could guide the formulation of innovative, fermented food with enhanced nutritional value.

Immuno- and glyco-histochemistry as a tool to evaluate the oregano supplemented feed effects in pig gut

Among oregano properties, its antioxidant and antibacterial effects are particularly interesting. Oregano is also able to induce a higher glycoconjugate production in gut, creating a physical barrier against microorganisms. This study evaluated the effects of adding an aqueous extract of oregano (OAE) to the diet of two homogenous groups of pigs during the finisher phase. The diets were as follows: control commercial diet (CTR group) and CTR diet supplemented (2 g/kg) with OAE (O group). Samples of ileum and caecum from the two groups were examined by conventional histochemistry to analyze complex carbohydrates and by immunohistochemistry to detect Bcl-2 Associate X protein (BAX), an indicator of oxidative stress. Glyco-histochemistry showed significant differences between the two groups. Immunohistochemistry revealed a lower presence of BAX in O group. The OAE supplementation improved the production of glycoconjugates, able to enhance in pig the protection of intestinal mucosa by means of direct and indirect defense actions. The reduced BAX immunostaining observed in O group may be an indicator of enhanced antioxidant action promoted by oregano. The results of this study can be used in further research to identify ways to improve endogenous defence ability, with the aim of reducing antibiotic use and preventing antimicrobial resistance.

Cathelicidin preserves intestinal barrier function in polymicrobial sepsis

Objectives

The intestinal epithelium compartmentalizes the sterile bloodstream and the commensal bacteria in the gut. Accumulating evidence suggests that this barrier is impaired in sepsis, aggravating systemic inflammation. Previous studies reported that cathelicidin is differentially expressed in various tissues in sepsis. However, its role in sepsis-induced intestinal barrier dysfunction has not been investigated.

Design

To examine the role of cathelicidin in polymicrobial sepsis, cathelicidin wild-(Cnlp^+/+) and knockout (Cnlp^−/−) mice underwent cecal-ligation and puncture (CLP) followed by the assessment of septic mortality and morbidity as well as histological, biochemical, immunological, and transcriptomic analyses in the ileal tissues. We also evaluated the prophylactic and therapeutic efficacies of vitamin D3 (an inducer of endogenous cathelicidin) in the CLP-induced murine polymicrobial sepsis model.

Results

The ileal expression of cathelicidin was increased by three-fold after CLP, peaking at 4 h. Knockout of Cnlp significantly increased 7-day mortality and was associated with a higher murine sepsis score. Alcian-blue staining revealed a reduced number of mucin-positive goblet cells, accompanied by reduced mucin expression. Increased number of apoptotic cells and cleavage of caspase-3 were observed. Cnlp deletion increased intestinal permeability to 4kD fluorescein-labeled dextran and reduced the expression of tight junction proteins claudin-1 and occludin. Notably, circulating bacterial DNA load increased more than two-fold. Transcriptome analysis revealed upregulation of cytokine/inflammatory pathway. Depletion of Cnlp induced more M1 macrophages and neutrophils compared with the wild-type mice after CLP. Mice pre-treated with cholecalciferol (an inactive form of vitamin D3) or treated with 1alpha, 25-dihydroxyvitamin D3 (an active form of VD3) had decreased 7-day mortality and significantly less severe symptoms. Intriguingly, the administration of cholecalciferol after CLP led to worsened 7-day mortality and the associated symptoms.

Conclusions

Endogenous cathelicidin promotes intestinal barrier integrity accompanied by modulating the infiltration of neutrophils and macrophages in polymicrobial sepsis. Our data suggested that 1alpha, 25-dihydroxyvitamin D3 but not cholecalciferol is a potential therapeutic agent for treating sepsis.

In vitro characterization and analysis of probiotic species in the chicken intestine by real-time polymerase chain reaction

Two experiments, 1 in vitro and 1 in vivo study, were conducted to analyze probiotic species characteristics and survival in the intestine of broiler birds. The in vitro study characterized the effect of bile salt supplementation and pH on the proliferation of Lactobacillus reuteri, Pediococcus acidilactici, Bifidobacterium animalis, and Enterococcus faecium. L. reuteri and P. acidilactici growth was maximal when the media was supplemented with 1.0% bile salt, whereas B. animalis and E. faecium growth was maximal when the media was supplemented with 0.5% bile salt. Altering the pH between 2.5 and 5.8 did not significantly (P > 0.05) alter the proliferation of L. reuteri and B. animalis. Decreasing the pH from 5.8 to 2.0 decreased P. acidilactici growth, whereas it increased the E. faecium proliferation. The in vivo study quantified the concentration of L. reuteri, P. acidilactici, B. animalis, E. faecium, and L. salivarius in different intestinal sections from birds supplemented with and without synbiotic containing the above 5 bacteria species. Birds were supplemented with and without synbiotic for 18 d, after which all birds were fed the same basal diet with no synbiotic. At 72 h of feeding, the basal diet with no synbiotics, when the probiotic species in the feed is expected not to confound the recovery of probiotic species from the intestine, intestinal contents were collected. L. reuteri, P. acidilactici, E. faecium, and L. salivarius were below detectable amount in the control group. L. reuteri concentration expressed as copy numbers/g and as percentage of total bacteria was highest in the jejunum and ileum, respectively. E. faecium concentration was highest in the ileum. The copy number of P. acidilactici increased at the duodenum and plateaued after duodenum. L. salivarius concentration was highest in the jejunum. It can be concluded that real-time PCR can be applied to quantify the concentrations of probiotic species in the intestine and probiotic species differ in their ability to colonize different sections of the intestine.

Potential prebiotic effect of a long-chain dextran produced by Weissella cibaria: an in vitro evaluation

Dextrans are homopolysaccharides of D-glucose units produced by lactic acid bacteria. They have several technological applications and potential utilisation in positively modulating gut microbiota is attracting increasing attention. Whereas the prebiotic activity of low polymerisation degree (DP) dextrans has been established, high DP dextrans still deserve deeper investigation. In the present study, a long linear chain dextran produced by Weissella cibaria was compared to inulin with regards to the growth of specific health-related taxa and to the production of organic acids in pH-controlled batch cultures of intestinal microbiota. qPCR quantification of Lactobacillus, Bifidobacterium, Prevotella, Bacteroides fragilis, and Faecalibacterium prausnitzii revealed differences in their relative abundance, depending on the carbon source, that reflected the pattern of fermentation products determined by HPLC. Dextran mainly enhanced the relative amount of Prevotella and Bacteroides, consistently with a favourable acetate-propionate ratio suggesting a promising utilisation as functional ingredient in the food industry.

Development and evaluation of a quantitative polymerase chain reaction for aquatic Streptococcus agalactiae based on the groEL gene

AIMS

The aim of this study was to develop a TaqMan quantitative polymerase chain reaction (qPCR), based on the Streptococcus agalactiae groEL gene, to specifically quantify levels of bacteria within samples derived from aquatic sources, particularly aquaculture. Enumeration of bacteria by qPCR was compared with culture-based methods.

METHODS AND RESULTS

The qPCR was sensitive to 33 isolates of S. agalactiae, representing 11 clonal complexes from aquatic, bovine and human hosts. The specificity of the assay was 92·5% at a threshold C_q value of 35. No cross-reaction with Streptococcus iniae was noted and of the 22 comparator species screened to test assay specificity, Streptococcus porcinus had a C_q value of 33·7 S, while Streptococcus gallolyticus subsp. macedonicus and Streptococcus ictaluri had one replicate value above the C_q threshold of 35 (34·5 and 34·4 respectively), while only S. agalactiae were detected with a C_q value of 30. The limit of detection of the assay was 1·7 copies per µl at C_q 35. Discrepancies between molecular and culture-based methods of enumeration were noted.

CONCLUSIONS

The qPCR was able to detect a diverse range of S. agalactiae isolates from different clonal complexes (CCs) and could distinguish between S. agalactiae and closely related species, notably S. iniae. The results suggest that a C_q 30 would be a very meaningful cut-off, allowing the detection of infected fish while ruling out all false positives.

SIGNIFICANCE AND IMPACT OF THE STUDY

This rapid and sensitive qPCR assay is useful to quantify DNA copy number in the laboratory and could prove useful for detecting low levels of S. agalactiae in aquaculture systems, including Oreochromis niloticus culture.

Abundance of Gut Microbiota, Concentration of Short-Chain Fatty Acids, and Inflammatory Markers Associated with Elevated Body Fat, Overweight, and Obesity in Female Adolescents

BACKGROUND AND AIMS

Overweight is ever more prevalent in the pediatric population, and this cardiometabolic factor can be associated with inflammatory markers, gut microbiota composition, and short-chain fatty acid (SCFA) concentrations. The aim of this study is to evaluate to what extent the abundance of gut microbiota phyla, SCFA concentrations, and inflammatory markers are associated with elevated body fat percentage (BF%), overweight, and obesity in female adolescents.

METHODS

An experimental and comparative study was conducted with 96 girls 14 to 19 years old. They were divided into 3 groups: G1-eutrophic (EUT) and adequate BF%; G2-EUT and high BF%; and G3-overweight (OW) or obese (OB) and high BF%. Waist circumference (WC), waist to height ratio (WtHR), and neck circumference (NC) were analyzed as indicators of central visceral adiposity. The BF% was evaluated by DEXA equipment. A food frequency questionnaire was used to evaluate the main types of food consumed in a week. The abundance of the Firmicutes, Bacteroidetes, and Proteobacteria phyla was measured by real-time polymerase chain reaction (RT-qPCR), and the SFCA concentrations (acetic, butyric, and propionic) were determined by high-performance liquid chromatography (HPLC). The inflammatory markers leptin, tumor necrosis factor-alpha, interleukin-6, and high-sensitivity C-reactive protein (hs-CRP) were assessed.

RESULTS

Female adolescents in groups G2 and G3 had greater central visceral adiposity and leptin concentration than those in group G1. No association was found between gut microbiota phyla abundance and SFCA concentrations in any of the groups. WC and frequency of consumption of oily and fatty foods were associated with Firmicutes abundance and SFCA concentrations. Girls with high WC also had the greatest leptin (p < 0.001) and hs-CRP (p = 0.035) concentrations.

CONCLUSIONS

Inflammatory markers showed association with increased BMI and high BF% in female adolescents. The abundance of Firmicutes was associated with WC and NC, but not with BMI classification or BF%. Specifically, WC and the consumption of oils and fats showed correlation with SCFA concentrations. Different anthropometric indicators, such as NC and WC, should be incorporated into the clinical evaluation of the nutritional status of individuals in the adolescent population.

Effect of administering kefir on the changes in fecal microbiota and symptoms of inflammatory bowel disease: A randomized controlled trial

BACKGROUND/AIMS

Kefir is a kind of fermented probiotic dairy product. The objective of the present study was to investigate the effects of kefir consumption on the fecal microflora and symptoms of patients with inflammatory bowel disease (IBD).

MATERIALS AND METHODS

Kefir was serially diluted and inoculated into de Man, Rogosa, and Sharpe agar and incubated at 37°C for 48 to 72 h under anaerobic conditions. This was a single-center, prospective, open-label randomized controlled trial. Forty-five patients with IBD were classified into two groups: 25 for treatment and 20 for control. A 400 mL/day kefir was administered to the patients for 4 weeks day and night. Their stool Lactobacillus, Lactobacillus kefiri, content was quantitated by real-time quantitative polymerase chain reaction before and after consumption. Abdominal pain, bloating, stool frequency, stool consistency, and feeling good scores were recorded in diaries daily by the patients.

RESULTS

A 5×107 CFU/mL count of lactic acid bacteria colony forming units was found in a kefir sample as the total average count. Lactobacillus bacterial load of feces of all subjects in the treatment group was between 104 and 109 CFU/g, and the first and last measurements were statistically significant (p=0.001 in ulcerative colitis and p=0.005 in Crohn's disease (CD)). The L. kefiri bacterial load in the stool of 17 subjects was measured as between 104 and 106 CFU/g. For patients with CD, there was a significant decrease in erythrocyte sedimentation rate and C-reactive protein, whereas hemoglobin increased, and for the last 2 weeks, bloating scores were significantly reduced (p=0.012), and feeling good scores increased (p=0.032).

CONCLUSION

According to our data, kefir consumption may modulate gut microbiota, and regular consumption of kefir may improve the patient's quality of life in the short term.