A combination of scGOS/lcFOS with Bifidobacterium breve M-16V protects suckling rats from rotavirus gastroenteritis

The protective role of prebiotics and probiotics on diarrhea and gut damage in the rotavirus-infected piglets

Rotavirus is one of the pathogenic causes that induce diarrhea in young animals, especially piglets, worldwide. However, nowadays, there is no specific drug available to treat the disease, and the related vaccines have no obvious efficiency in some countries. Via analyzing the pathogenesis of rotavirus, it inducing diarrhea is mainly due to disturb enteric nervous system, destroy gut mucosal integrity, induce intracellular electrolyte imbalance, and impair gut microbiota and immunity. Many studies have already proved that prebiotics and probiotics can mitigate the damage and diarrhea induced by rotavirus infection in hosts. Based on these, the current review summarizes and discusses the effects and mechanisms of prebiotics and probiotics on rotavirus-induced diarrhea in piglets. This information will highlight the basis for the swine production utilization of prebiotics and probiotics in the prevention or treatment of rotavirus infection in the future.

Impact of Limosilactobacillus fermentum probiotic treatment on gut microbiota composition in sahiwal calves with rotavirus diarrhea: A 16S metagenomic analysis study"

BACKGROUND

Diarrhea poses a major threat to bovine calves leading to mortality and economic losses. Among the causes of calf diarrhea, bovine rotavirus is a major etiological agent and may result in dysbiosis of gut microbiota. The current study was designed to investigate the effect of probiotic Limosilactobacillus fermentum (Accession No.OR504458) on the microbial composition of rotavirus-infected calves using 16S metagenomic analysis technique. Screening of rotavirus infection in calves below one month of age was done through clinical signs and Reverse Transcriptase PCR. The healthy calves (n = 10) were taken as control while the infected calves (n = 10) before treatment was designated as diarrheal group were treated with Probiotic for 5 days. All the calves were screened for the presence of rotavirus infection on each day and fecal scoring was done to assess the fecal consistency. Infected calves after treatment were designated as recovered group. Fecal samples from healthy, recovered and diarrheal (infected calves before sampling) were processed for DNA extraction while four samples from each group were processed for 16S metagenomic analysis using Illumina sequencing technique and analyzed via QIIME 2.

RESULTS

The results show that Firmicutes were more abundant in the healthy and recovered group than in the diarrheal group. At the same time Proteobacteria was higher in abundance in the diarrheal group. Order Oscillospirales dominated healthy and recovered calves and Enterobacterials dominated the diarrheal group. Alpha diversity indices show that diversity indices based on richness were higher in the healthy group and lower in the diarrheal group while a mixed pattern of clustering between diarrheal and recovered groups samples in PCA plots based on beta diversity indices was observed.

CONCLUSION

It is concluded that probiotic Limosilactobacillus Fermentum N-30 ameliorate the dysbiosis caused by rotavirus diarrhea and may be used to prevent diarrhea in pre-weaned calves after further exploration.

Microbiota-Derived Extracellular Vesicles as a Postbiotic Strategy to Alleviate Diarrhea and Enhance Immunity in Rotavirus-Infected Neonatal Rats

Rotavirus (RV) infection is a major cause of acute gastroenteritis in children under 5 years old, resulting in elevated mortality rates in low-income countries. The efficacy of anti-RV vaccines is limited in underdeveloped countries, emphasizing the need for novel strategies to boost immunity and alleviate RV-induced diarrhea. This study explores the effectiveness of interventions involving extracellular vesicles (EVs) from probiotic and commensal E. coli in mitigating diarrhea and enhancing immunity in a preclinical model of RV infection in suckling rats. On days 8 and 16 of life, variables related to humoral and cellular immunity and intestinal function/architecture were assessed. Both interventions enhanced humoral (serum immunoglobulins) and cellular (splenic natural killer (NK), cytotoxic T (Tc) and positive T-cell receptor γδ (TCRγδ) cells) immunity against viral infections and downregulated the intestinal serotonin receptor-3 (HTR3). However, certain effects were strain-specific. EcoR12 EVs activated intestinal CD68, TLR2 and IL-12 expression, whereas EcN EVs improved intestinal maturation, barrier properties (goblet cell numbers/mucin 2 expression) and absorptive function (villus length). In conclusion, interventions involving probiotic/microbiota EVs may serve as a safe postbiotic strategy to improve clinical symptoms and immune responses during RV infection in the neonatal period. Furthermore, they could be used as adjuvants to enhance the immunogenicity and efficacy of anti-RV vaccines.

Composition and evolutionary characterization of the gut microbiota in pigs

The intestinal microbiota plays significant role in the physiology and functioning of host organisms. However, there is limited knowledge of the composition and evolution of microbiota-host relationships from wild ancestors to modern domesticated species. In this study, the 16S rRNA gene V3-V4 in the intestinal contents of different pig breeds was analyzed and was compared using high-throughput sequencing. This identified 18 323 amplicon sequence variants, of which the Firmicutes and Actinobacteria phyla and Bifidobacterium and Allobaculum genera were most prevalent in wild pigs (WP). In contrast, Proteobacteria and Firmicutes predominated in Chinese Shanxi Black pigs (CSB), while Firmicutes were the most prevalent phylum in Large White pigs (LW) and Iberian pigs (IB), followed by Bacteroidetes in IB and Proteobacteria in LW. At the genus level, Shigella and Lactobacillus were most prevalent in CSB and LW, while Actinobacillus and Sarcina predominated in IB. Differential gene expression together with phylogenetic and functional analyses indicated significant differences in the relative abundance of microbial taxa between different pig breeds. Although many microbial taxa were common to both wild and domestic pigs, significant diversification was observed in bacterial genes that potentially influence host phenotypic traits. Overall, these findings suggested that both the composition and functions of the microbiota were closely associated with domestication and the evolutionary changes in the host. The members of the microbial communities were vertically transmitted in pigs, with evidence of co-evolution of both the hosts and their intestinal microbial communities. These results enhance our understanding and appreciation of the complex interactions between intestinal microbes and hosts and highlight the importance of applying this knowledge in agricultural and microbiological research.

Novel Dietary Approach with Probiotics, Prebiotics, and Synbiotics to Mitigate Antimicrobial Resistance and Subsequent Out Marketplace of Antimicrobial Agents: A Review

Antimicrobial resistance (AMR) is a significant public health concern worldwide. The continuous use and misuse of antimicrobial agents have led to the emergence and spread of resistant strains of bacteria, which can cause severe infections that are difficult to treat. One of the reasons for the constant development of new antimicrobial agents is the need to overcome the resistance that has developed against existing drugs. However, this approach is not sustainable in the long term, as bacteria can quickly develop resistance to new drugs as well. Additionally, the development of new drugs is costly and time-consuming, and there is no guarantee that new drugs will be effective or safe. An alternative approach to combat AMR is to focus on improving the body's natural defenses against infections by using probiotics, prebiotics, and synbiotics, which are helpful to restore and maintain a healthy balance of bacteria in the body. Probiotics are live microorganisms that can be consumed as food or supplements to promote gut health and improve the body's natural defenses against infections. Prebiotics are non-digestible fibers that stimulate the growth of beneficial bacteria in the gut, while synbiotics are a combination of probiotics and prebiotics that work together to improve gut health. By promoting a healthy balance of bacteria in the body, these can help to reduce the risk of infections and the need for antimicrobial agents. Additionally, these approaches are generally safe and well tolerated, and they do not contribute to the development of AMR. In conclusion, the continuous development of new antimicrobial agents is not a sustainable approach to combat AMR. Instead, alternative approaches such as probiotics, prebiotics, and synbiotics should be considered as they can help to promote a healthy balance of bacteria in the body and reduce the need for antibiotics.

Effect of Rotavirus Infection and 2'-Fucosyllactose Administration on Rat Intestinal Gene Expression

Viral infections are described as modifying host gene expression; however, there is limited insight regarding rotavirus (RV) infections. This study aimed to assess the changes in intestinal gene expression after RV infection in a preclinical model, and the effect of 2-fucosyllactose (2'-FL) on this process. From days 2 to 8 of life, rats were supplemented with the dietary oligosaccharide 2'-FL or vehicle. In addition, an RV was inoculated on day 5 to nonsupplemented animals (RV group) and to 2'-FL-fed animals (RV+2'-FL group). Incidence and severity of diarrhea were established. A portion from the middle part of the small intestine was excised for gene expression analysis by microarray kit and qPCR. In nonsupplemented animals, RV-induced diarrhea upregulated host antiviral genes (e.g., Oas1a, Irf7, Ifi44, Isg15) and downregulated several genes involved in absorptive processes and intestinal maturation (e.g., Onecut2, and Ccl19). The 2'-FL-supplemented and infected animals had less diarrhea; however, their gene expression was affected in a similar way as the control-infected animals, with the exception of some immunity/maturation markers that were differentially expressed (e.g., Ccl12 and Afp). Overall, assessing the expression of these key genes may be useful in the evaluation of the efficacy of nutritional interventions or treatments for RV infection.

Pathogen-Specific Benefits of Probiotic and Synbiotic Use in Childhood Acute Gastroenteritis: An Updated Review of the Literature

Probiotics represent viable microorganisms which are found within the normal gut microbiota, that exert strain-specific benefits in the management of several gastrointestinal disorders in children, including acute gastroenteritis. This review aims to evaluate the pathogen-specific role of probiotic supplementation in childhood diarrhea. A search of scientific databases was conducted to identify studies which investigated efficacy of probiotics and synbiotics in influencing outcome of acute gastroenteritis of known etiology. We identified 32 studies, most of which analyzed impact of probiotic supplementation in rotavirus gastroenteritis, while a very limited number of these conducted a separate analysis on bacterial diarrhea. Lactobacillus rhamnosus (L. rhamnosus), L. reuteri and S. boulardii still remain the most researched strains, with a proven role in decreasing diarrhea and hospitalization duration, especially in the setting of rotavirus infection. Combined products containing at least one of the aforementioned strains also performed similarly and might also influence rotavirus fecal shedding. Rotavirus immunization status has also been proposed as a significant influencing factor of probiotic use impact. The paucity of research focusing on bacterial etiologies, as well as of clinical trials conducted within ambulatory care units leaves room for further research on the matter, which needs to include larger cohort studies.

Immunomodulation of B Lymphocytes by Prebiotics, Probiotics and Synbiotics: Application in Pathologies

INTRODUCTION

Prebiotics, probiotics and synbiotics are known to have major beneficial effects on human health due to their ability to modify the composition and the function of the gut mucosa, the gut microbiota and the immune system. These components largely function in a healthy population throughout different periods of life to confer homeostasis. Indeed, they can modulate the composition of the gut microbiota by increasing bacteria strands that are beneficial for health, such as Firmicute and Bifidobacteria, and decreasing harmful bacteria, such as Enteroccocus. Their immunomodulation properties have been extensively studied in different innate cells (dendritic cells, macrophages, monocytes) and adaptive cells (Th, Treg, B cells). They can confer a protolerogenic environment but also modulate pro-inflammatory responses. Due to all these beneficial effects, these compounds have been investigated to prevent or to treat different diseases, such as cancer, diabetes, allergies, autoimmune diseases, etc. Regarding the literature, the effects of these components on dendritic cells, monocytes and T cells have been studied and presented in a number of reviews, but their impact on B-cell response has been less widely discussed.

CONCLUSIONS

For the first time, we propose here a review of the literature on the immunomodulation of B-lymphocytes response by prebiotics, probiotics and synbiotics, both in healthy conditions and in pathologies.

DISCUSSION

Promising studies have been performed in animal models, highlighting the potential of prebiotics, probiotics and synbiotics intake to treat or to prevent diseases associated with B-cell immunomodulation, but this needs to be validated in humans with a full characterization of B-cell subsets and not only the humoral response.

Efficacy of zinc oxide nanoparticles and Bifidobacterium bifidum Extraction on anaerobic bacteria isolated from patients with diarrhea

Infectious acute diarrhea may be prevented with probiotics; because they make up the majority of the colonic flora in breastfed newborns and are likely to contribute to the lower incidence of diarrhea in this population, Bifidobacteria are particularly appealing as probiotics agents. The present study was designed to identify anaerobic bacteria, especially C. difficile the main reason for dysentery associated with antibiotics. Detect the ability of each ZnoNPs and B. bifidum to inhibit bacterial growth. During the period from March to October 2019, (100) children and adults who came to Salah al-deen hospital in Tikrit city participated in the study under the supervision of a physician. All samples were transported using a carry Blair if late one or two hours after collection and culturing. The collected models were also cultured on Xylose Lysine Deoxycholate agar, Salmonella Shigella agar, Eosin methylene blue agar, and MacConkey agar. For initiated diagnoses of the Enterobacteriaceae, Blood agar is used to detect beta-hemolytic isolates, recover enteric bacteria other than Enterobacteriaceae, and evaluate the results of oxidase tests. To diagnose bacterium kinds, biochemical reactions and motility tests were used. Impact of ZnoNPs, and B. bifidum antibiotic In vitro. The results of 100 dysentery feces samples were obtained into (60%) samples for males and (40%) for females. Eighty-two positively impacted anaerobically on growth media like Clostridium complicate agar and MacConkey agar (18%) other than bacteria. In contrast, negative samples revealed 10 (55.56 percent) samples for males and 8 (44.44 percent) samples for females. The same stool samples were taken and cultured on Clostridium difficile agar and MacConkey agar under anaerobic and ideal incubation conditions. 15% and 67% of isolates appeared on MacConkey agar of the total number of samples, while 18% showed negative growth. Finally, Zn NPs showed their ability to inhibit Clostridium complicated segregate lean on the condensation 5 mg/ml, and it caused the inhibitory effect on Clostridium to complicate by 10-22 of the diameter of inhibition. The Inhibition Zone Dimeter ranged from 8 to 25 mm for isolates when condensation was utilized at 2.5 mg/ml. According to the findings, the widths of the inhibitory zones for isolates of C. difficile containing B. bifidum supernatant mg/ml ranged from 9 to 24 mm. Keywords: Zinc oxide nanoparticles, Probiotic, Bifidobacterium bifidum, Clostridium difficile

Staphylococcus epidermidis' Overload During Suckling Impacts the Immune Development in Rats

Mastitis is an inflammation of the mammary gland occurring in 3-33% of the breastfeeding mothers. The majority of mastitis cases have an infectious etiology. More than 75% of infectious mastitis are caused by Staphylococcus epidermidis and Staphylococcus aureus and involves breast milk microbiota alteration, which, may have an impact in lactating infant. The aim of this study was to analyze in rats during the suckling period and later in life the impact of a high and a low overload of Staphylococcus epidermidis, similarly as it occurs during the clinical and the subclinical mastitis, respectively. From days 2 to 21 of life, suckling rats were daily supplemented with low (Ls group) or high (Hs group) dose of S. epidermidis. Body weight and fecal humidity were periodically recorded. On days 21 and 42 of life, morphometry, hematological variables, intestinal gene expression, immunoglobulin (Ig) and cytokine profile and spleen cells' phenotype were measured. Although no differences were found in body weight, Ls and Hs groups showed higher body length and lower fecal humidity. Both doses induced small changes in lymphocytes subpopulations, reduced the plasma levels of Ig and delayed the Th1/Th2 balance causing a bias toward the Th2 response. No changes were found in cytokine concentration. The low dose affected the Tc cells intestinal homing pattern whereas the high dose had an impact on the hematological variables causing leukocytosis and lymphocytosis and also influenced the intestinal barrier maturation. In conclusion, both interventions with Staphylococcus epidermidis overload during suckling, affects the immune system development in short and long term.

A Galactooligosaccharide Product Decreases the Rotavirus Infection in Suckling Rats

The leading cause of gastroenteritis among young children worldwide is the Group A rotaviruses (RV), which produce a wide range of symptoms, from a limited diarrhea to severe dehydration and even death. After an RV infection, immunity is not complete and less severe re-infections usually occur. These infections could be ameliorated by nutritional interventions with bioactive compounds, such as prebiotics. The aim of this research was to study the impact of a particular galactooligosaccharide (B-GOS) on the RV symptomatology and immune response during two consecutive infections. Lewis neonatal rats were inoculated with SA11 (first RV infection) on day 6 of life and with EDIM (second RV infection) on day 17 of life. B-GOS group was administered by oral gavage with a daily dose of B-GOS between days three to nine of life. Clinical and immunological variables were assessed during both infective processes. In the first infection, after the prebiotic intervention with B-GOS, a lower incidence, duration, and overall severity of the diarrhea (p < 0.05) was observed. In addition, it improved another severity indicator, the fecal weight output, during the diarrhea period (p < 0.05). The second RV infection failed in provoking diarrhea in the groups studied. The immune response during first infection with SA11 was not affected by B-GOS administration and had no impact on second infection, but the prebiotic intervention significantly increased IFN-γ and TNF-α intestinal production after the second infection (p < 0.05). In summary, B-GOS supplementation is able to reduce the incidence and severity of the RV-associated diarrhea and to influence the immune response against RV infections.

Preventive Effect of a Postbiotic and Prebiotic Mixture in a Rat Model of Early Life Rotavirus Induced-Diarrhea

Rotavirus (RV) is the main cause of gastroenteritis in children. Prebiotics and, more recently, postbiotics are used for preventing and treating gastrointestinal infections. The aim of this study was to analyze the effects of a Lactofidus^TM, short-chain galacto-oligosaccharides (scGOS) and long-chain fructo-oligosaccharides (lcFOS) mixture, and their combination on RV infection, in a rat model, for early life diarrhea. Fifteen litters of suckling rats were intragastrically administered daily with the vehicle, the prebiotic mixture, the postbiotic or the combination. The RV was inoculated on day 5 and then fecal samples were clinically evaluated daily. Viral shedding, intestinal permeability assay, in vitro blocking assay, immunoglobulin profiles, and anti-RV response were assessed at day 8 and 16 of life. Cecal microbiota composition, intestinal gene expression, and short chain fatty acids (SCFAs) were analyzed at day 16. The incidence and severity of diarrhea were significantly reduced by all the supplementations. Moreover, they showed blocking activity, changes in the immunoglobulin profiles, in gut microbiota, and in the intestinal gene expression. The prebiotic mixture reduced gut permeability and changed the SCFA profile, whereas the postbiotic enhanced the expression of Toll-like receptors (TLRs). The combination preserved most of the individual observed effects, and furthermore, complementary effects, such as an increase in white blood cells and lymphocytes recruitment, as well as upregulation of TLR7 and TLR9 gene expression.

Potential Associations Between Microbiome and COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has plunged the world into a major crisis. The disease is characterized by strong infectivity, high morbidity, and high mortality. It is still spreading in some countries. Microbiota and their metabolites affect human physiological health and diseases by participating in host digestion and nutrition, promoting metabolic function, and regulating the immune system. Studies have shown that human microecology is associated with many diseases, including COVID-19. In this research, we first reviewed the microbial characteristics of COVID-19 from the aspects of gut microbiome, lung microbime, and oral microbiome. We found that significant changes take place in both the gut microbiome and airway microbiome in patients with COVID-19 and are characterized by an increase in conditional pathogenic bacteria and a decrease in beneficial bacteria. Then, we summarized the possible microecological mechanisms involved in the progression of COVID-19. Intestinal microecological disorders in individuals may be involved in the occurrence and development of COVID-19 in the host through interaction with ACE2, mitochondria, and the lung-gut axis. In addition, fecal bacteria transplantation (FMT), prebiotics, and probiotics may play a positive role in the treatment of COVID-19 and reduce the fatal consequences of the disease.

Effects of a Postbiotic and Prebiotic Mixture on Suckling Rats' Microbiota and Immunity

Human milk serves as a model for infant formula providing nutritional solutions for infants not able to receive enough mother’s milk. Infant formulas aim to mimic the composition and functionality of human milk by providing ingredients reflecting those of the latest human milk insights, such as prebiotics, probiotics and postbiotics. The aim of this study was to examine the effects of the supplementation with a postbiotic (Lactofidus^TM) and its combination with the prebiotics short-chain galactooligosaccharides (scGOS) and long-chain fructooligosaccharides (lcFOS) in a preclinical model of healthy suckling rats. Pups were supplemented daily with Lactofidus^TM (POST group) and/or scGOS/lcFOS (P+P and PRE groups, respectively). Body weight and fecal consistency were analyzed. At the end of the study, immunoglobulin (Ig) profile, intestinal gene expression, microbiota composition and short chain fatty acid (SCFA) proportion were quantified. The supplementation with all nutritional interventions modulated the Ig profile, but the prebiotic mixture and the postbiotic induced differential effects: whereas scGOS/lcFOS induced softer feces and modulated microbiota composition and SCFA profile, Lactofidus™ upregulated Toll-like receptors gene expression. The use of the combination of scGOS/lcFOS and Lactofidus™ showed the effects observed for the oligosaccharides separately, as well as showing a synergistic impact on animal growth. Thus, the combined use of both products seems to be a good strategy to modulate immune and microbial features in early life.

A New Extracellular β-Galactosidase Producing Kluyveromyces sp. PCH397 from Yak Milk and Its Applications for Lactose Hydrolysis and Prebiotics Synthesis

β-Galactosidase is a crucial glycoside hydrolase enzyme with potential applications in the dairy, food, and pharmaceutical industries. The enzyme is produced in the intracellular environment by bacteria and yeast. The present study reports yeast Kluyveromyces sp. PCH397 isolated from yak milk, which has displayed extracellular β-galactosidase activity in cell-free supernatant through the growth phase. To investigate further, cell counting and methylene blue staining of culture collected at different growth stages were performed and suggested for possible autolysis or cell lysis, thereby releasing enzymes into the extracellular medium. The maximum enzyme production (9.94 ± 2.53U/ml) was achieved at 37 °C in a modified deMan, Rogosa, and Sharpe (MRS) medium supplemented with lactose (1.5%) as a carbon source. The enzyme showed activity at a wide temperature range (4-50 °C), maximum at 50 °C in neutral pH (7.0). In addition to the hydrolysis of lactose (5.0%), crude β-galactosidase also synthesized vital prebiotics (i.e., lactulose and galacto-oligosaccharides (GOS)). Additionally, β-fructofuranosidase (FFase) activity in the culture supernatant ensued the synthesis of a significant prebiotic, fructo-oligosaccharides (FOS). Hence, the unique features such as extracellular enzymes production, efficient lactose hydrolysis, and broad temperature functionality by yeast isolate PCH397 are of industrial relevance. In conclusion, the present study unrevealed for the first time, extracellular production of β-galactosidase from a new yeast source and its applications in milk lactose hydrolysis and synthesis of valuable prebiotics of industrial importance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-021-00955-1.

Modulatory Effects of Probiotics During Pathogenic Infections With Emphasis on Immune Regulation

In order to inhibit pathogenic complications and to enhance animal and poultry growth, antibiotics have been extensively used for many years. Antibiotics applications not only affect target pathogens but also intestinal beneficially microbes, inducing long-lasting changes in intestinal microbiota associated with diseases. The application of antibiotics also has many other side effects like, intestinal barrier dysfunction, antibiotics residues in foodstuffs, nephropathy, allergy, bone marrow toxicity, mutagenicity, reproductive disorders, hepatotoxicity carcinogenicity, and antibiotic-resistant bacteria, which greatly compromise the efficacy of antibiotics. Thus, the development of new antibiotics is necessary, while the search for antibiotic alternatives continues. Probiotics are considered the ideal antibiotic substitute; in recent years, probiotic research concerning their application during pathogenic infections in humans, aquaculture, poultry, and livestock industry, with emphasis on modulating the immune system of the host, has been attracting considerable interest. Hence, the adverse effects of antibiotics and remedial effects of probiotics during infectious diseases have become central points of focus among researchers. Probiotics are live microorganisms, and when given in adequate quantities, confer good health effects to the host through different mechanisms. Among them, the regulation of host immune response during pathogenic infections is one of the most important mechanisms. A number of studies have investigated different aspects of probiotics. In this review, we mainly summarize recent discoveries and discuss two important aspects: (1) the application of probiotics during pathogenic infections; and (2) their modulatory effects on the immune response of the host during infectious and non-infectious diseases.

Lentinan administration alleviates diarrhea of rotavirus-infected weaned pigs via regulating intestinal immunity

BACKGROUND

Lentinan (LNT) may regulate many important physiological functions of human and animals. This study aimed to verify whether LNT administration could relieve diarrhea via improving gut immunity in rotavirus (RV)-challenged weaned pigs.

METHODS

Twenty-eight weaned pigs were randomly fed 2 diets containing 0 or 84 mg/kg LNT product for 19 d (n = 14). RV infection was executed on d 15. After extracting polysaccharides from LNT product, its major monosaccharides were analyzed. Then, LNT polysaccharide was used to administrate RV-infected IPEC-J2 cells.

RESULTS

Dietary LNT supplementation supported normal function of piglets even when infected with RV, as reflected by reduced growth performance loss and diarrhea prevalence, and maintained gut immunity (P < 0.05). The polysaccharide was isolated from LNT product, which molecular weight was 5303 Da, and major monosaccharides included glucose, arabinose and galactose. In RV-infected IPEC-J2 cells, this polysaccharide significantly increased cell viability (P < 0.05), and significantly increased anti-virus immunity via regulating pattern recognition receptors and host defense peptides (P < 0.05).

CONCLUSION

Those results suggest that LNT administration increases the piglets' resistance to RV-induced stress, likely by supporting intestinal immunity.

The Complex Interactions Between Rotavirus and the Gut Microbiota

Human rotavirus (HRV) is the leading worldwide cause of acute diarrhea-related death in children under the age of five. RV infects the small intestine, an important site of colonization by the microbiota, and studies over the past decade have begun to reveal a complex set of interactions between RV and the gut microbiota. RV infection can temporarily alter the composition of the gut microbiota and probiotic administration alleviates some symptoms of infection in vivo, suggesting reciprocal effects between the virus and the gut microbiota. While development of effective RV vaccines has offered significant protection against RV-associated mortality, vaccine effectiveness in low-income countries has been limited, potentially due to regional differences in the gut microbiota. In this mini review, we briefly detail research findings to date related to HRV vaccine cohorts, studies of natural infection, explorations of RV-microbiota interactions in gnotobiotic pig models, and highlight various in vivo and in vitro models that could be used in future studies to better define how the microbiota may regulate RV infection and host antiviral immune responses.

Sexual Dimorphism Has Low Impact on the Response against Rotavirus Infection in Suckling Rats

Rotaviruses (RVs) are the leading pathogens causing severe and acute diarrhea in children and animals. It is well known that sex contributes to shaping immune responses, thus it could also influence the incidence and severity of the RV infection. The aim of this study was to analyze the influence of sexual dimorphism on RV infection and its antibody (Ab) immune response in a suckling rat model. Neonatal suckling rats were intragastrically RV-inoculated and clinical indexes derived from fecal samples, as well as immune variables were evaluated. Higher severity of diarrhea, fecal weight and viral elimination were observed in males compared to females (p < 0.05). Regarding the adaptative immunity, the RV shaped the immune response to lower IgG1 levels and an increased Th1/Th2-associated Ab response (p < 0.05). Although females had lower IgG2a levels than males (p < 0.05), the specific anti-RV antibody levels were not sex influenced. In fact, at this age the passive transfer of anti-RV antibodies through breast milk was the critical factor for clustering animals, independently of their sex. It can be concluded that male and female diarrhea severity in RV infection is slightly influenced by sexual dimorphism and is not associated with the specific immune response against the virus.

Characterization of the bacterial microbiota composition and evolution at different intestinal tract in wild pigs (Sus scrofa ussuricus)

Commensal microorganisms are essential to the normal development and function of many aspects of animal biology, including digestion, nutrient absorption, immunological development, behaviors, and evolution. The specific microbial composition and evolution of the intestinal tracts of wild pigs remain poorly characterized. This study therefore sought to assess the composition, distribution, and evolution of the intestinal microbiome of wild pigs. For these analyses, 16S rRNA V3-V4 regions from five gut sections prepared from each of three wild sows were sequenced to detect the microbiome composition. These analyses revealed the presence of 6,513 operational taxonomic units (OTUs) mostly distributed across 17 phyla and 163 genera in these samples, with Firmicutes and Actinobacteria being the most prevalent phyla of microbes present in cecum and jejunum samples, respectively. Moreover, the abundance of Actinobacteria in wild pigs was higher than that in domestic pigs. At the genus level the Bifidobacterium and Allobaculum species of microbes were most abundant in all tested gut sections, with higher relative abundance in wild pigs relative to domestic pigs, indicating that in the process of pig evolution, the intestinal microbes also evolved, and changes in the intestinal microbial diversity could have been one of the evolutionary forces of pigs. Intestinal microbial functional analyses also revealed the microbes present in the small intestine (duodenum, jejunum, and ileum) and large intestine (cecum and colon) of wild pigs to engage distinct metabolic spatial structures and pathways relative to one another. Overall, these results offer unique insights that would help to advance the current understanding of how the intestinal microbes interact with the host and affect the evolution of pigs.

Strain-Specific Probiotic Properties of Bifidobacteria and Lactobacilli for the Prevention of Diarrhea Caused by Rotavirus in a Preclinical Model

Probiotic supplementation with different lactobacilli and bifidobacterial strains has demonstrated beneficial effects in infectious diarrhea caused by rotavirus (RV) in young children. Preclinical models of RV infection might be a good strategy to screen for the efficacy of new probiotic strains or to test their comparative efficacy. Neonatal Lewis rats were supplemented with Bifidobacterium breve M-16V, Lactobacillus acidophilus NCFM, Lactobacillus helveticus R0052, or Lactobacillus salivarius PS2 from days 2–14 of life. On day five, animals received RV SA-11 orally. Fecal samples were collected daily, weighed, and scored for the calculation of severity and incidence of diarrhea. In addition, fecal pH and fecal viral shedding were measured. Animals were sacrificed at the end of the study and their blood was obtained for the quantification of RV-specific immunoglobulins. RV infection was induced in ~90% of the animals. All probiotics caused a reduction of several clinical variables of severity and incidence of diarrhea, except L. salivarius PS2. L. acidophilus NCFM, B. breve M-16V, and L. helveticus R0052 seemed to be very effective probiotic strains. In addition, all Lactobacillus strains reduced the viral elimination one day post-inoculation. No differences were detected in the specific anti-RV humoral response. The present study highlights the strain-specific effects of probiotics and identifies promising probiotics for use in ameliorating and preventing RV-induced diarrhea in children, for example by including them in infant formulas.

Oligosaccharides Modulate Rotavirus-Associated Dysbiosis and TLR Gene Expression in Neonatal Rats

Colonization of the gut in early life can be altered through multiple environmental factors. The present study aimed to investigate the effects of 2'-fucosyllactose (2'-FL), a mixture of short-chain galactooligosaccharides/long-chain fructooligosaccharides (scGOS/lcFOS) 9:1 and their combination (scGOS/lcFOS/2'-FL) on dysbiosis induced during rotavirus (RV) diarrhea in neonatal rats, elucidating crosstalk between bacteria and the immune system. The dietary interventions were administered daily by oral gavage at days 2-8 of life in neonatal Lewis rats. On day 5, RV SA11 was intragastrically delivered to induce infection and diarrhea assessment, microbiota composition, and gene expression of Toll-like receptors (TLRs) in the small intestine were studied. All dietary interventions showed reduction in clinical variables of RV-induced diarrhea. RV infection increased TLR2 expression, whereas 2'-FL boosted TLR5 and TLR7 expressions and scGOS/lcFOS increased that of TLR9. RV-infected rats displayed an intestinal dysbiosis that was effectively prevented by the dietary interventions, and consequently, their microbiota was more similar to microbiota of the noninfected groups. The preventive effect of 2'-FL, scGOS/lcFOS, and their combination on dysbiosis associated to RV diarrhea in rats could be due to changes in the crosstalk between gut microbiota and the innate immune system.

Effects of Bifidobacterium infantis on cytokine-induced neutrophil chemoattractant and insulin-like growth factor-1 in the ileum of rats with endotoxin injury

BACKGROUND

The digestive tract is the maximal immunizing tissue in the body, and mucosal integrity and functional status of the gut is very important to maintain a healthy organism. Severe infection is one of the most common causes of gastrointestinal dysfunction, and the pathogenesis is closely related to endotoxemia and intestinal barrier injury. Bifidobacterium is one of the main probiotics in the human body that is involved in digestion, absorption, metabolism, nutrition, and immunity. Bifidobacterium plays an important role in maintaining the intestinal mucosal barrier integrity. This study investigated the protective mechanism of Bifidobacterium during ileal injury in rats.

AIM

To investigate the effects of Bifidobacterium on cytokine-induced neutrophil chemoattractant (CINC) and insulin-like growth factor 1 (IGF-1) in the ileum of rats with endotoxin injury.

METHODS

Preweaning rats were randomly divided into three groups: Control (group C), model (group E) and treatment (group T). Group E was intraperitoneally injected with lipopolysaccharide (LPS) to create an animal model of intestinal injury. Group T was intragastrically administered Bifidobacterium suspension 7 d before LPS. Group C was intraperitoneally injected with normal saline. The rats were killed at 2, 6 or 12 h after LPS or physiological saline injection to collect ileal tissue samples. The expression of ileal CINC mRNA was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), and expression of ileal IGF-1 protein and mRNA was detected by immunohistochemistry and RT-PCR, respectively.

RESULTS

The ileum of rats in Group C did not express CINC mRNA, ileums from Group E expressed high levels, which was then significantly decreased in Group T (F = 23.947, P < 0.05). There was no significant difference in CINC mRNA expression at different times (F = 0.665, P > 0.05). There was a high level of IGF-1 brown granules in ileal crypts and epithelial cells in Group C, sparse staining in Group E, and dark, dense brown staining in Group T. There was a significant difference between Groups C and E and Groups E and T (P < 0.05). There was no significant difference in IGF-1 protein expression at different times (F = 1.269, P > 0.05). IGF-1 mRNA expression was significantly different among the three groups (P < 0.05), though not at different times (F = 0.086, P > 0.05).

CONCLUSION

Expression of CINC mRNA increased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium reduced CINC mRNA expression. IGF-1 protein and mRNA expression decreased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium prevented the decrease in IGF-1 expression. Bifidobacterium may increase IGF-1 expression and enhance intestinal immune barrier function in rats with endotoxin injury.

Prevention of Rotavirus Diarrhea in Suckling Rats by a Specific Fermented Milk Concentrate with Prebiotic Mixture

Several microbial modulatory concepts, such as certain probiotics and prebiotics, confer protection against gastrointestinal infections, among which is acute diarrhea caused by the rotavirus (RV). Other microbiota modulators, such as postbiotics, produced during fermentation, might also have the potential to counteract RV infection. In light of this, a fermented milk, made by using Bifidobacterium breve C50 (BbC50) and Streptococcus thermophilus 065 (St065) with a prebiotic mixture-short chain galactooligosaccharides/long chain fructooligosaccharides (scGOS/lcFOS 9:1)-with potential to impact the intestinal microbiota composition was tested. An RV infected rat model was used to evaluate the amelioration of the infectious process and the improvement of the immune response induced by the fermented milk with prebiotic mixture. The dietary intervention caused a reduction in the clinical symptoms of diarrhea, such as severity and incidence. Furthermore, a modulation of the immune response was observed, which might enhance the reduction of the associated diarrhea. In addition, the fermented milk with prebiotic mixture was able to bind the virus and reduce its clearance. In conclusion, the postbiotic components in the fermented milk in combination with the prebiotics used here showed protective properties against RV infection.

Rotavirus Double Infection Model to Study Preventive Dietary Interventions

Rotaviruses are the main cause of acute diarrhea among young children worldwide with an increased frequency of reinfection. Several life style factors, such as dietary components, may influence such processes by affecting the outcome of the first rotavirus infection and therefore having a beneficial impact on the anti-rotavirus immune responses during any subsequent reinfections. The aim of this research was to develop a double-infection model in rat that mimics real-life clinical scenarios and would be useful in testing whether nutritional compounds can modulate the rotavirus-associated disease and immune response. Three experimental designs and a preventive dietary-like intervention were conducted in order to achieve a differential response in the double-infected animals compared to the single-infected ones and to study the potential action of a modulatory agent in early life. Diarrhea was only observed after the first infection, with a reduction of fecal pH and fever. After the second infection an increase in body temperature was also found. The immune response against the second infection was regulated by the preventive effect of the dietary-like intervention during the first infection in terms of specific antibodies and DTH. A rotavirus-double-infection rat model has been developed and is suitable for use in future preventive dietary intervention studies.

Supplementation With 2'-FL and scGOS/lcFOS Ameliorates Rotavirus-Induced Diarrhea in Suckling Rats

Rotavirus (RV) is considered to be the most common cause of gastroenteritis among infants aged less than 5 years old. Human milk bioactive compounds have the ability to modulate the diarrheic process caused by several intestinal pathogens. This study aimed to evaluate the potential protective role of a specific human milk oligosaccharide, 2′-fucosyllactose (2′-FL), a mixture of the prebiotic short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides 9:1 (GOS/FOS) and their combination (2′-FL+GOS/FOS) on RV-induced diarrhea in suckling rats. The nutritional intervention was performed from the second to the sixteenth day of life by oral gavage and on day 5 an RV strain was orally administered to induce infection. Fecal samples were scored daily to assess the clinical pattern of severity, incidence and duration of diarrhea. Blood and tissues were obtained at day 8 and 16 in order to evaluate the effects on the epithelial barrier and the mucosal and systemic immune responses. In the assessment of severity, incidence and duration of diarrhea, both 2′-FL and GOS/FOS displayed a beneficial effect in terms of amelioration. However, the mechanisms involved seemed to differ: 2′-FL displayed a direct ability to promote intestinal maturation and to enhance neonatal immune responses, while GOS/FOS induced an intestinal trophic effect and an RV-blocking action. The combination of 2′-FL and GOS/FOS showed additive effects in some variables. Therefore, it could be a good strategy to add these compounds in combination to infant formulas, to protect against human RV-induced diarrhea in children.

Preventive Effect of a Synbiotic Combination of Galacto- and Fructooligosaccharides Mixture With Bifidobacterium breve M-16V in a Model of Multiple Rotavirus Infections

Rotavirus (RV) causes morbidity and mortality among infants worldwide, and there is evidence that probiotics and prebiotics can have a positive influence against infective processes such as that due to RV. The aim of this study was to evidence a preventive role of one prebiotic mixture (of short-chain galactooligosaccharide/long-chain fructooligosaccharide), the probiotic Bifidobacterium breve M-16V and the combination of the prebiotic and the probiotic, as a synbiotic, in a suckling rat double-RV infection model. Hyperimmune bovine colostrum was used as protection control. The first infection was induced with RV SA11 and the second one with EDIM. Clinical variables and immune response were evaluated after both infections. Dietary interventions ameliorated clinical symptoms after the first infection. The prebiotic and the synbiotic significantly reduced viral shedding after the first infection, but all the interventions showed higher viral load than in the RV group after the second infection. All interventions modulated ex vivo antibody and cytokine production, gut wash cytokine levels and small intestine gene expression after both infections. In conclusion, a daily supplement of the products tested in this preclinical model is highly effective in preventing RV-induced diarrhea but allowing the boost of the early immune response for a future immune response against reinfection, suggesting that these components may be potential agents for modulating RV infection in infants.

Modulation of rotavirus severe gastroenteritis by the combination of probiotics and prebiotics

Annual mortality rates due to infectious diarrhea are about 2.2 million; children are the most vulnerable age group to severe gastroenteritis, representing group A rotaviruses as the main cause of disease. One of the main factors of rotavirus pathogenesis is the NSP4 protein, which has been characterized as a viral toxin involved in triggering several cellular responses leading to diarrhea. Furthermore, the rotavirus protein NSP1 has been associated with interferon production inhibition by inducing the degradation of interferon regulatory factors IRF3, IRF5, and IRF7. On the other hand, probiotics such as Bifidobacterium and Lactobacillus species in combination with prebiotics such as inulin, HMO, scGOS, lcFOS have been associated with improved generalized antiviral response and anti-rotavirus effect by the reduction of rotavirus infectivity and viral shedding, decreased expression of NSP4 and increased levels of specific anti-rotavirus IgAs. Moreover, these probiotics and prebiotics have been related to shorter duration and severity of rotavirus diarrhea, to the prevention of infection and reduced incidence of reinfections. In this review we will discuss in detail about the rotavirus pathogenesis and immunity, and how probiotics such as Lactobacillus and Bifidobacterium species in combination with prebiotics have been associated with the prevention or modulation of rotavirus severe gastroenteritis.

A fermented milk concentrate and a combination of short-chain galacto-oligosaccharides/long-chain fructo-oligosaccharides/pectin-derived acidic oligosaccharides protect suckling rats from rotavirus gastroenteritis

Human milk contains bioactive compounds that confer a protective role against gastrointestinal infections. In order to find supplements for an infant formula able to mimic these benefits of breast-feeding, two different concepts were tested. The products consisted of the following: (1) a Bifidobacterium breve- and Streptococcus thermophilus-fermented formula and (2) a combination of short-chain galacto-oligosaccharides/long-chain fructo-oligosaccharides with pectin-derived acidic oligosaccharides. A rotavirus infection suckling rat model was used to evaluate improvements in the infectious process and in the immune response of supplemented animals. Both nutritional concepts caused amelioration of the clinical symptoms, even though this was sometimes hidden by softer stool consistency in the supplemented groups. Both products also showed certain modulation of immune response, which seemed to be enhanced earlier and was accompanied by a faster resolution of the process. The viral shedding and the in vitro blocking assay suggest that these products are able to bind the viral particles, which can result in a milder infection. In conclusion, both concepts evaluated in this study showed interesting protective properties against rotavirus infection, which deserve to be investigated further.

Preclinical Immunomodulation by the Probiotic Bifidobacterium breve M-16V in Early Life

This study aimed to investigate the effect of supplementation with the probiotic Bifidobacterium breve M-16V on the maturation of the intestinal and circulating immune system during suckling. In order to achieve this purpose, neonatal Lewis rats were supplemented with the probiotic strain from the 6th to the 18th day of life. The animals were weighed during the study, and faecal samples were obtained and evaluated daily. On day 19, rats were euthanized and intestinal wash samples, mesenteric lymph node (MLN) cells, splenocytes and intraepithelial lymphocytes (IEL) were obtained. The probiotic supplementation in early life did not modify the growth curve and did not enhance the systemic immune maturation. However, it increased the proportion of cells bearing TLR4 in the MLN and IEL, and enhanced the percentage of the integrin αEβ7+ and CD62L+ cells in the MLN and that of the integrin αEβ7+ cells in the IEL, suggesting an enhancement of the homing process of naïve T lymphocytes to the MLN, and the retention of activated lymphocytes in the intraepithelial compartment. Interestingly, B. breve M-16V enhanced the intestinal IgA synthesis. In conclusion, supplementation with the probiotic strain B. breve M-16V during suckling improves the development of mucosal immunity in early life.