Bifidobacterium longum subsp infantis CECT7210-supplemented formula reduces diarrhea in healthy infants: a randomized controlled trial

Bifidobacterium longum subsp. longum BG-L47 boosts growth and activity of Limosilactobacillus reuteri DSM 17938 and its extracellular membrane vesicles

The aim of this study was to identify a Bifidobacterium strain that improves the performance of Limosilactobacillus reuteri DSM 17938. Initial tests showed that Bifidobacterium longum subsp. longum strains boosted the growth of DSM 17938 during in vivo-like conditions. Further characterization revealed that one of the strains, BG-L47, had better bile and acid tolerance compared to BG-L48, as well as mucus adhesion compared to both BG-L48 and the control strain BB536. BG-L47 also had the capacity to metabolize a broad range of carbohydrates and sugar alcohols. Mapping of glycoside hydrolase (GH) genes of BG-L47 and BB536 revealed many GHs associated with plant-fiber utilization. However, BG-L47 had a broader phenotypic fiber utilization capacity. In addition, B. longum subsp. longum cells boosted the bioactivity of extracellular membrane vesicles (MV) produced by L. reuteri DSM 17938 during co-cultivation. Secreted 5'-nucleotidase (5'NT), an enzyme that converts AMP into the signal molecule adenosine, was increased in MV boosted by BG-L47. The MV exerted an improved antagonistic effect on the pain receptor transient receptor potential vanilloid 1 (TRPV1) and increased the expression of the immune development markers IL-6 and IL-1ß in a peripheral blood mononuclear cell (PBMC) model. Finally, the safety of BG-L47 was evaluated both by genome safety assessment and in a human safety study. Microbiota analysis showed that the treatment did not induce significant changes in the composition. In conclusion, B. longum subsp. longum BG-L47 has favorable physiological properties, can boost the in vitro activity of L. reuteri DSM 17938, and is safe for consumption, making it a candidate for further evaluation in probiotic studies.

IMPORTANCE

By using probiotics that contain a combination of strains with synergistic properties, the likelihood of achieving beneficial interactions with the host can increase. In this study, we first performed a broad screening of Bifidobacterium longum subsp. longum strains in terms of synergistic potential and physiological properties. We identified a superior strain, BG-L47, with favorable characteristics and potential to boost the activity of the known probiotic strain Limosilactobacillus reuteri DSM 17938. Furthermore, we demonstrated that BG-L47 is safe for consumption in a human randomized clinical study and by performing a genome safety assessment. This work illustrates that bacteria-bacteria interactions differ at the strain level and further provides a strategy for finding and selecting companion strains of probiotics.

A Probiotic Bacterium with Activity against the Most Frequent Bacteria and Viruses Causing Pediatric Diarrhea: Bifidobacterium longum subsp. infantis CECT 7210 (B. infantis IM1®)

The second leading cause of death in children under five years old is diarrheal disease. Probiotics, specifically bifidobacteria, have been associated with a reduction in the number of diarrhea episodes and their severity in babies. In this paper, we summarize the preclinical and clinical evidence of the efficacy of B. longum subsp. infantis IM1® against various gastrointestinal pathogens using in vitro models, animal models, and clinical studies carried out in our laboratory. The preclinical data demonstrate that IM1® effectively inhibits rotavirus replication (by up to 36.05%) in MA-104 and HT-29 cells and from infection (up to 48.50%) through the production of an 11-amino-acid peptide. IM1® displays the capability to displace pathogens from enterocytes, particularly Cronobacter sakazakii and Salmonella enterica, and to reduce the adhesion to the HT29 cells of C. sakazakii and Shigella sonnei. In animal models, the IM1® strain exhibits in vivo protection against rotavirus and improves the clinical symptomatology of bacterial gastroenteritis. A clinical study involving infants under 3 months of age revealed that IM1® reduced episodes of diarrhea, proving to be safe, well tolerated, and associated with a lower prevalence of constipation. B. infantis IM1® emerges as an effective probiotic, diminishing episodes of diarrhea caused by gastrointestinal pathogens.

The Genome of Bifidobacterium longum subsp. infantis YLGB-1496 Provides Insights into Its Carbohydrate Utilization and Genetic Stability

Bifidobacterium longum subsp. infantis YLGB-1496 (YLGB-1496) is a probiotic strain isolated from human breast milk. The application of YLGB-1496 is influenced by carbohydrate utilization and genetic stability. This study used genome sequencing and morphology during continuous subculture to determine the carbohydrate utilization characteristics and genetic stability of YLGB-1496. The complete genome sequence of YLGB-1496 consists of 2,758,242 base pairs, 2442 coding sequences, and a GC content of 59.87%. A comparison of carbohydrate transport and metabolism genes of Bifidobacterium longum subsp. infantis (B. infantis) showed that YLGB-1496 was rich in glycosyl hydrolase 13, 20, 25, and 109 gene families. During continuous subculture, the growth characteristics and fermentation activity of the strain were highly stable. The bacterial cell surface and edges of the 1000th-generation strains were progressively smoother and well-defined, with no perforations or breaks in the cell wall. There were 20 SNP loci at the 1000th generation, fulfilling the requirement of belonging to the same strain. The presence of genes associated with cell adhesion and the absence of resistance genes supported the probiotic characteristics of the strain. The data obtained in this study provide insights into broad-spectrum carbohydrate utilization, genomic stability, and probiotic properties of YLGB-1496, which provide theoretical support to promote the use of YLGB-1496.

Bifidobacterium infantis supplementation versus placebo in early life to improve immunity in infants exposed to HIV: a protocol for a randomized trial

INTRODUCTION

Infants who are born from mothers with HIV (infants who are HIV exposed but uninfected; iHEU) are at higher risk of morbidity and display multiple immune alterations compared to infants who are HIV-unexposed (iHU). Easily implementable strategies to improve immunity of iHEU, and possibly subsequent clinical health outcomes, are needed. iHEU have altered gut microbiome composition and bifidobacterial depletion, and relative abundance of Bifidobacterium infantis has been associated with immune ontogeny, including humoral and cellular vaccine responses. Therefore, we will assess microbiological and immunological phenotypes and clinical outcomes in a randomized, double-blinded trial of B. infantis Rosell®-33 versus placebo given during the first month of life in South African iHEU.

METHODS

This is a parallel, randomised, controlled trial. Two-hundred breastfed iHEU will be enrolled from the Khayelitsha Site B Midwife Obstetric Unit in Cape Town, South Africa and 1:1 randomised to receive 8 × 109 CFU B. infantis Rosell®-33 daily or placebo for the first 4 weeks of life, starting on day 1-3 of life. Infants will be followed over 36 weeks with extensive collection of meta-data and samples. Primary outcomes include gut microbiome composition and diversity, intestinal inflammation and microbial translocation and cellular vaccine responses. Additional outcomes include biological (e.g. gut metabolome and T cell phenotypes) and clinical (e.g. growth and morbidity) outcome measures.

DISCUSSION

The results of this trial will provide evidence whether B. infantis supplementation during early life could improve health outcomes for iHEU.

ETHICS AND DISSEMINATION

Approval for this study has been obtained from the ethics committees at the University of Cape Town (HREC Ref 697/2022) and Seattle Children's Research Institute (STUDY00003679).

TRIAL REGISTRATION

Pan African Clinical Trials Registry Identifier: PACTR202301748714019.

CLINICAL

TRIALS

gov: NCT05923333.

PROTOCOL VERSION

Version 1.8, dated 18 July 2023.

What are Normal Defecation Patterns in Healthy Children up to Four Years of Age? A Systematic Review and Meta-Analysis

OBJECTIVE

To summarize available data on defecation frequency and stool consistency of healthy children up to age 4 in order to estimate normal references values.

STUDY DESIGN

Systematic review including cross-sectional, observational, and interventional studies published in English, that reported on defecation frequency and/or stool consistency in healthy children 0-4 years old.

RESULTS

Seventy-five studies were included with 16 393 children and 40 033 measurements of defecation frequency and/or stool consistency. Based on visual inspection of defecation frequency data, a differentiation was made between two age categories: young infants (0-14 weeks old) and young children (15 weeks-4 years old). Young infants had a mean defecation frequency of 21.8 per week (95 % CI, 3.9-35.2) compared with 10.9 (CI, 5.7-16.7) in young children (P < .001). Among young infants, human milk-fed (HMF) infants had the highest mean defecation frequency per week (23.2 [CI, 8.8-38.1]), followed by formula-fed (FF) infants (13.7 [CI 5.4-23.9]), and mixed-fed (MF) infants (20.7 [CI, 7.0-30.2]). Hard stools were infrequently reported in young infants (1.5%) compared with young children (10.5%), and a reduction in the frequency of soft/watery stools was observed with higher age (27.0% in young infants compared with 6.2% in young children). HMF young infants had softer stools compared with FF young infants.

CONCLUSIONS

Young infants (0-14 weeks old) have softer and more frequent stools compared with young children (15 weeks-4 years old).

Pre-, pro-, syn-, and Postbiotics in Infant Formulas: What Are the Immune Benefits for Infants?

The first objective of infant formulas is to ensure the healthy growth of neonates and infants, as the sole complete food source during the first months of life when a child cannot be breastfed. Beyond this nutritional aspect, infant nutrition companies also try to mimic breast milk in its unique immuno-modulating properties. Numerous studies have demonstrated that the intestinal microbiota under the influence of diet shapes the maturation of the immune system and influences the risk of atopic diseases in infants. A new challenge for dairy industries is, therefore, to develop infant formulas inducing the maturation of immunity and the microbiota that can be observed in breastfed delivered vaginally, representing reference infants. Streptococcus thermophilus, Lactobacillus reuteri DSM 17938, Bifidobacterium breve (BC50), Bifidobacterium lactis Bb12, Lactobacillus fermentum (CECT5716), and Lactobacillus rhamnosus GG (LGG) are some of the probiotics added to infant formula, according to a literature review of the past 10 years. The most frequently used prebiotics in published clinical trials are fructo-oligosaccharides (FOSs), galacto-oligosaccharides (GOSs), and human milk oligosaccharides (HMOs). This review sums up the expected benefits and effects for infants of pre-, pro-, syn-, and postbiotics added to infant formula regarding the microbiota, immunity, and allergies.

Efficacy of Bifidobacterium longum alone or in multi-strain probiotic formulations during early life and beyond

The significance of Bifidobacterium to human health can be appreciated from its early colonization of the neonatal gut, where Bifidobacterium longum represents the most abundant species. While its relative abundance declines with age, it is further reduced in several diseases. Research into the beneficial properties of B. longum has unveiled a range of mechanisms, including the production of bioactive molecules, such as short-chain fatty acids, polysaccharides, and serine protease inhibitors. From its intestinal niche, B. longum can have far-reaching effects in the body influencing immune responses in the lungs and even skin, as well as influencing brain activity. In this review, we present the biological and clinical impacts of this species on a range of human conditions beginning in neonatal life and beyond. The available scientific evidence reveals a strong rationale for continued research and further clinical trials that investigate the ability of B. longum to treat or prevent a range of diseases across the human lifespan.

Enhancement of IgA production by membrane vesicles derived from Bifidobacterium longum subsp. infantis

Immunoglobulin A (IgA) is involved in the maintenance of gut homeostasis. Although the oral administration of bifidobacteria increases the amount of fecal IgA, the effects of bifidobacteria on intestinal immunity remain unclear. We found and characterized membrane vesicles (MVs) derived from Bifidobacterium longum subsp. infantis toward host immune cells. Bifidobacterium infantis MVs consisted of a cytoplasmic membrane, and extracellular solute-binding protein (ESBP) was specifically detected. In the presence of B. infantis MVs or recombinant ESBP, RAW264 cells produced the pro-inflammatory cytokine IL-6. IgA was produced by Peyer's patches cells following the addition of B. infantis MVs. Therefore, ESBP of B. infantis MVs is involved in the production of IgA by acquired immune cells via the production of IL-6 by innate immune cells.

Health Effects of Infant Formula Supplemented with Probiotics or Synbiotics in Infants and Toddlers: Systematic Review with Network Meta-Analysis

Supplementation of infant and follow-up formula with probiotics or synbiotics has become a common practice. In 2011 and 2017, the evidence regarding the impact of these interventions was analysed systematically. Recently new evidence was published. To evaluate through a systematic review with network meta-analysis the evidence on the impact of infant formula supplemented with probiotics or synbiotics for healthy infants and 36-month-old toddlers. RCTs published between 1999-2019 for infant formulas supplemented with probiotics alone or synbiotics in healthy infants and toddlers were identified. Data analysis included clinical (gastrointestinal symptoms, risk reduction of infectious diseases, use of antibiotics, weight/height gain and frequency of adverse events) and non-clinical outcomes (changes in faecal microbiota and immune parameters). A random effect model was used. Hedges' standard mean difference (SMD) and risk ratio (RR) were calculated. Rank analysis was performed to evaluate the superiority of each intervention. Twenty-six randomised controlled trials with 35 direct comparisons involving 1957 children receiving probiotic-supplemented formula and 1898 receiving control formula were reviewed. The mean duration of intervention was 5.6 ± 2.84 months. Certain strains demonstrated a reduction in episodes of colic, number of days with fever and use of antibiotics; however, there was considerable heterogeneity which reduced the level of certainty of effect. No significant effects were observed on weight, height or changes in faecal proportions of Bifidobacteria, Lactobacillus, Bacteroides or Clostridia. Although there is some evidence that may support a potential benefit of probiotic or synbiotic supplementation of infant formulas, variation in the quality of existing trials and the heterogeneity of the data preclude the establishment of robust recommendations.

Bifidobacterium longum subsp. infantis CECT 7210 Reduces Inflammatory Cytokine Secretion in Caco-2 Cells Cultured in the Presence of Escherichia coli CECT 515

Previous works have described the activity of Bifidobacterium longum subsp. infantis CECT 7210 (also commercially named B. infantis IM-1^®) against rotavirus in mice and intestinal pathogens in piglets, as well as its diarrhea-reducing effect on healthy term infants. In the present work, we focused on the intestinal immunomodulatory effects of B. infantis IM-1^® and for this purpose we used the epithelial cell line isolated from colorectal adenocarcinoma Caco-2 and a co-culture system of human dendritic cells (DCs) from peripheral blood together with Caco-2 cells. Single Caco-2 cultures and Caco-2: DC co-cultures were incubated with B. infantis IM-1^® or its supernatant either in the presence or absence of Escherichia coli CECT 515. The B. infantis IM-1^® supernatant exerted a protective effect against the cytotoxicity caused by Escherichia coli CECT 515 on single cultures of Caco-2 cells as viability reached the values of untreated cells. B. infantis IM-1^® and its supernatant also decreased the secretion of pro-inflammatory cytokines by Caco-2 cells and the co-cultures incubated in the presence of E. coli CECT 515, with the response being more modest in the latter, which suggests that DCs modulate the activity of Caco-2 cells. Overall, the results obtained point to the immunomodulatory activity of this probiotic strain, which might underlie its previously reported beneficial effects.

Assessment of the Effects of the Synbiotic Combination of Bifidobacterium longum subsp. infantis CECT 7210 and Oligofructose-Enriched Inulin Against Digestive Bacterial Infections in a Piglet Model

The use of bifidobacteria as probiotics has proven to be beneficial in gastroenteric infections. Furthermore, prebiotics such as inulin can enhance the survival and growth of these bacteria. Two trials were performed to evaluate the effects of the administration of Bifidobacterium longum subsp. infantis CECT 7210 and oligofructose-enriched inulin against Salmonella enterica serovar Typhimurium or enterotoxigenic Escherichia coli (ETEC) F4. A total of 72 (Salmonella trial) and 96 (ETEC F4 trial) weaned piglets were used in a 2 × 2 design (with or without synbiotic, inoculated or not with the pathogen). After adaptation, animals were orally inoculated. Performance and clinical signs were evaluated. On days 4 and 8 (Salmonella trial) and 3 and 7 (ETEC F4 trial) post-inoculation (PI), one animal per pen was euthanized. Blood, digestive content and tissue samples were collected and microbiological counts, fermentation products, serum inflammatory markers and ileum histomorphometry analysis were performed. Both challenges had an impact on faecal consistency (p < 0.001), including the faecal shedding of Salmonella and increased numbers of enterobacteria and coliforms. The synbiotic administration did not have any effect on pathogen loads but induced changes in the fermentation profile, such as increased valeric acid in both trials as well as decreased acetic acid, except for Salmonella-challenged animals. The effect on propionate varied among trials, increasing in challenged synbiotic-treated pigs and decreasing in non-challenged ones in the Salmonella trial (P interaction = 0.013), while the opposed occurred in the ETEC F4 trial (P interaction = 0.013). The administration of the synbiotic increased intraepithelial lymphocytes (IEL; p = 0.039) on day 8 PI in the Salmonella trial and a similar trend occurred in non-challenged pigs in the ETEC F4 trial (P interaction = 0.086). The results did not provide evidence of reduced pathogen load with the synbiotic, although a modulation in fermentative activity could be identified depending on the challenge. Consistent increases were found in IEL, suggesting that this synbiotic combination has some immunomodulatory properties.

Bifidobacterium spp. as functional foods: A review of current status, challenges, and strategies

Members of Bifidobacterium are among the first microbes to colonize the human intestine naturally, their abundance and diversity in the colon are closely related to host health. Recently, the gut microbiota has been gradually proven to be crucial mediators of various metabolic processes between the external environment and the host. Therefore, the health-promoting benefits of Bifidobacterium spp. and their applications in food have gradually been widely concerned. The main purpose of this review is to comprehensively introduce general features, colonization methods, and safety of Bifidobacterium spp. in the human gut, highlighting its health benefits and industrial applications. On this basis, the existing limitations and scope for future research are also discussed. Bifidobacteria have beneficial effects on the host's digestive system, immune system, and nervous system. However, the first prerequisite for functioning is to have enough live bacteria before consumption and successfully colonize the colon after ingestion. At present, strain breeding, optimization (e.g., selecting acid and bile resistant strains, adaptive evolution, high cell density culture), and external protection technology (e.g., microencapsulation and protectants) are the main strategies to address these challenges in food application.

Efficacy of Probiotic Compounds in Relieving Constipation and Their Colonization in Gut Microbiota

A number of studies have confirmed the relationship between constipation and gut microbiota. Additionally, many human and animal experiments have identified probiotics as effectors for the relief of constipation symptoms. In this study, probiotic compounds, including Lactobacillus acidophilus LA11-Onlly, Lacticaseibacillus rhamnosus LR22, Limosilactobacillus reuteri LE16, Lactiplantibacillus plantarum LP-Onlly, and Bifidobacterium animalis subsp. lactis BI516, were administered to mice with loperamide-induced constipation, and the impacts of these strains on constipation-related indicators and gut microbiota were evaluated. The effects of probiotic compounds on constipation relief were associated with various aspects, including gastrointestinal transit rate, number and weight of stools, serum and intestinal gastrointestinal regulatory hormones, and serum cytokines. Some of the probiotic compounds, including Limosilactobacillus reuteri, Lactiplantibacillus plantarum, and Lacticaseibacillus rhamnosus, were found to colonize the intestinal tract. Furthermore, higher dosages promoted the colonization of specific strains. This study yields a new perspective for the clinical use of probiotics to improve constipation symptoms by combining strains with different mechanisms for the alleviation of constipation.

Probiotic Supplementation for Promotion of Growth in Children: A Systematic Review and Meta-Analysis

Probiotics are commonly prescribed to promote a healthy gut microbiome in children. Our objective was to investigate the effects of probiotic supplementation on growth outcomes in children 0-59 months of age. We conducted a systematic review and meta-analysis which included randomized controlled trials (RCTs) that administered probiotics to children aged 0-59 months, with growth outcomes as a result. We completed a random-effects meta-analysis and calculated a pooled standardized mean difference (SMD) or relative risk (RR) and reported with a 95% confidence interval (CI). We included 79 RCTs, 54 from high-income countries (HIC), and 25 from low- and middle-income countries (LMIC). LMIC data showed that probiotics may have a small effect on weight (SMD: 0.26, 95% CI: 0.11-0.42, grade-certainty = low) and height (SMD 0.16, 95% CI: 0.06-0.25, grade-certainty = moderate). HIC data did not show any clinically meaningful effect on weight (SMD: 0.01, 95% CI: -0.04-0.05, grade-certainty = moderate), or height (SMD: -0.01, 95% CI: -0.06-0.04, grade-certainty = moderate). There was no evidence that probiotics affected the risk of adverse events. We conclude that in otherwise healthy children aged 0-59 months, probiotics may have a small but heterogenous effect on weight and height in LMIC but not in children from HIC.

Role of Bifidobacteria on Infant Health

Bifidobacteria are among the predominant microorganisms during infancy, being a dominant microbial group in the healthy breastfed infant and playing a crucial role in newborns and infant development. Not only the levels of the Bifidobacterium genus but also the profile and quantity of the different bifidobacterial species have been demonstrated to be of relevance to infant health. Although no definitive proof is available on the causal association, reduced levels of bifidobacteria are perhaps the most frequently observed alteration of the intestinal microbiota in infant diseases. Moreover, Bifidobacterium strains have been extensively studied by their probiotic attributes. This review compiles the available information about bifidobacterial composition and function since the beginning of life, describing different perinatal factors affecting them, and their implications on different health alterations in infancy. In addition, this review gathers exhaustive information about pre-clinical and clinical studies with Bifidobacterium strains as probiotics in neonates.

Probiotic Interventions Alleviate Food Allergy Symptoms Correlated With Cesarean Section: A Murine Model

Delivery by cesarean section (CS) is linked to an increased incidence of food allergies in children and affects early gut microbiota colonization. Furthermore, emerging evidence has connected disordered intestinal microbiota to food allergies. Here, we investigated the impact of CS on a rat model for food allergy to ovalbumin (OVA). Rats delivered by CS were found to be more responsive to OVA sensitization than vaginally born ones, displaying a greater reduction in rectal temperature upon challenge, worse diarrhea, and higher levels of OVA-specific antibodies and histamine. 16S rRNA sequencing of feces revealed reduced levels of Lactobacillus and Bifidobacterium in the CS rats. Preventative supplementation with a probiotic combination containing Lactobacillus and Bifidobacterium could protect CS rats against an allergic response to OVA, indicating that the microbiota dysbiosis contributes to CS-related response. Additionally, probiotic intervention early in life might help to rebuild aberrant Th2 responses and tight junction proteins, both of which have been linked to CS-related high allergic reactions. Taken together, this study shows that disordered intestinal microbiota plays an essential role in the pathogenesis of food allergy mediated by CS. More importantly, interventions that modulate the microbiota composition in early life are therapeutically relevant for CS-related food allergies.

Bioactive Compounds in Infant Formula and Their Effects on Infant Nutrition and Health: A Systematic Literature Review

Infant formulas are an alternative to replace or supplement human milk when breastfeeding is not possible. The knowledge of human milk's bioactive compounds and their beneficial effects has attracted the interest of researchers in the field of infant nutrition, as well as researchers of technology and food sciences that seek to improve the nutritional characteristics of infant formulas. Several scientific studies evaluate the optimization of infant formula composition. The bioactive compound inclusion has been used to upgrade the quality and nutrition of infant formulas. In this context, the purpose of this systematic literature review is to assess the scientific evidence of bioactive compounds present in infant formulas (α-lactalbumin, lactoferrin, taurine, milk fat globule membrane, folates, polyamines, long-chain polyunsaturated fatty acids, prebiotics, and probiotics) and their effects on infant nutrition and health. Through previously determined criteria, studies published in the last fifteen years from five different databases were included to identify the advances in the optimization of infant formula composition. Over the last few years, there has been optimization of the infant formula composition, not only to increase the similarities in their content of macro and micronutrients but also to include novel bioactive ingredients with potential health benefits for infants. Although the infant food industry has advanced in the last years, there is no consensus on whether novel bioactive ingredients added to infant formulas have the same functional effects as the compounds found in human milk. Thus, further studies about the impact of bioactive compounds in infant nutrition are fundamental to infant health.

Probiotics in the dairy industry-Advances and opportunities

The past two decades have witnessed a global surge in the application of probiotics as functional ingredients in food, animal feed, and pharmaceutical products. Among food industries, the dairy industry is the largest sector where probiotics are employed in a number of dairy products including sour/fermented milk, yogurt, cheese, butter/cream, ice cream, and infant formula. These probiotics are either used as starter culture alone or in combination with traditional starters, or incorporated into dairy products following fermentation, where their presence imparts many functional characteristics to the product (for instance, improved aroma, taste, and textural characteristics), in addition to conferring many health-promoting properties. However, there are still many challenges related to the stability and functionality of probiotics in dairy products. This review highlights the advances, opportunities, and challenges of application of probiotics in dairy industries. Benefits imparted by probiotics to dairy products including their role in physicochemical characteristics and nutritional properties (clinical and functional perspective) are also discussed. We transcend the traditional concept of the application of probiotics in dairy products and discuss paraprobiotics and postbiotics as a newly emerged concept in the field of probiotics in a particular relation to the dairy industry. Some potential applications of paraprobiotics and postbiotics in dairy products as functional ingredients for the development of functional dairy products with health-promoting properties are briefly elucidated.

Effects of the Administration of Bifidobacterium longum subsp. infantis CECT 7210 and Lactobacillus rhamnosus HN001 and Their Synbiotic Combination With Galacto-Oligosaccharides Against Enterotoxigenic Escherichia coli F4 in an Early Weaned Piglet Model

We evaluated the potential of multi-strain probiotic (Bifidobacterium longum subsp. infantis CECT 7210 and Lactobacillus rhamnosus HN001) with or without galacto-oligosaccharides against enterotoxigenic Escherichia coli (ETEC) F4 infection in post-weaning pigs. Ninety-six piglets were distributed into 32 pens assigned to five treatments: one non-challenged (CTR+) and four challenged: control diet (CTR-), with probiotics (>3 × 10¹⁰ CFU/kg body weight each, PRO), prebiotic (5%, PRE), or their combination (SYN). After 1 week, animals were orally inoculated with ETEC F4. Feed intake, weight, and clinical signs were recorded. On days 4 and 8 post-inoculation (PI), one animal per pen was euthanized and samples from blood, digesta, and tissues collected. Microbiological counts, ETEC F4 real-time PCR (qPCR) quantification, fermentation products, serum biomarkers, ileal histomorphometry, and genotype for mucin 4 (MUC4) polymorphism were determined. Animals in the PRO group had similar enterobacteria and coliform numbers to the CTR+ group, and the ETEC F4 prevalence, the number of mitotic cells at day 4 PI, and villus height at day 8 PI were between that observed in the CTR+ and CTR- groups. The PRO group exhibited reduced pig major acute-phase protein (Pig-MAP) levels on day 4 PI. The PRE diet group presented similar reductions in ETEC F4 and Pig-MAP, but there was no effect on microbial groups. The SYN group showed reduced fecal enterobacteria and coliform counts after the adaptation week but, after the inoculation, the SYN group showed lower performance and more animals with high ETEC F4 counts at day 8 PI. SYN treatment modified the colonic fermentation differently depending on the MUC4 polymorphism. These results confirm the potential of the probiotic strains and the prebiotic to fight ETEC F4, but do not show any synergy when administered together, at least in this animal model.

Transient Effect of Infant Formula Supplementation on the Intestinal Microbiota

Breastfeeding is the gold standard for feeding infants because of its long-term benefits to health and development, but most infants in the United States are not exclusively breastfed in the first six months. We enrolled 24 infants who were either exclusively breastfed or supplemented with formula by the age of one month. We collected diet information, stool samples for evaluation of microbiotas by 16S rRNA sequencing, and blood samples for assessment of immune development by flow cytometry from birth to 6 months of age. We further typed the Bifidobacterium strains in stool samples whose 16S rRNA sequencing showed the presence of Bifidobacteriaceae. Supplementation with formula during breastfeeding transiently changed the composition of the gut microbiome, but the impact dissipated by six months of age. For example, Bifidobacterium longum, a bacterial species highly correlated with human milk consumption, was found to be significantly different only at 1 month of age but not at later time points. No immunologic differences were found to be associated with supplementation, including the development of T-cell subsets, B cells, or monocytes. These data suggest that early formula supplementation, given in addition to breast milk, has minimal lasting impact on the gut microbiome or immunity.

Probiotics for treating acute infectious diarrhoea

BACKGROUND

Probiotics may be effective in reducing the duration of acute infectious diarrhoea.

OBJECTIVES

To assess the effects of probiotics in proven or presumed acute infectious diarrhoea.

SEARCH METHODS

We searched the trials register of the Cochrane Infectious Diseases Group, MEDLINE, and Embase from inception to 17 December 2019, as well as the Cochrane Controlled Trials Register (Issue 12, 2019), in the Cochrane Library, and reference lists from studies and reviews. We included additional studies identified during external review.

SELECTION CRITERIA

Randomized controlled trials comparing a specified probiotic agent with a placebo or no probiotic in people with acute diarrhoea that is proven or presumed to be caused by an infectious agent.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied inclusion criteria, assessed risk of bias, and extracted data. Primary outcomes were measures of diarrhoea duration (diarrhoea lasting ≥ 48 hours; duration of diarrhoea). Secondary outcomes were number of people hospitalized in community studies, duration of hospitalization in inpatient studies, diarrhoea lasting ≥ 14 days, and adverse events.

MAIN RESULTS

We included 82 studies with a total of 12,127 participants. These studies included 11,526 children (age < 18 years) and 412 adults (three studies recruited 189 adults and children but did not specify numbers in each age group). No cluster-randomized trials were included. Studies varied in the definitions used for "acute diarrhoea" and "end of the diarrhoeal illness" and in the probiotic(s) tested. A total of 53 trials were undertaken in countries where both child and adult mortality was low or very low, and 26 where either child or adult mortality was high. Risk of bias was high or unclear in many studies, and there was marked statistical heterogeneity when findings for the primary outcomes were pooled in meta-analysis. Effect size was similar in the sensitivity analysis and marked heterogeneity persisted. Publication bias was demonstrated from funnel plots for the main outcomes. In our main analysis of the primary outcomes in studies at low risk for all indices of risk of bias, no difference was detected between probiotic and control groups for the risk of diarrhoea lasting ≥ 48 hours (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.91 to 1.09; 2 trials, 1770 participants; moderate-certainty evidence); or for duration of diarrhoea (mean difference (MD) 8.64 hours shorter, 95% CI 29.4 hours shorter to 12.1 hours longer; 6 trials, 3058 participants; very low-certainty evidence). Effect size was similar and marked heterogeneity persisted in pre-specified subgroup analyses of the primary outcomes that included all studies. These included analyses limited to the probiotics Lactobacillus rhamnosus GG and Saccharomyces boulardii. In six trials (433 participants) of Lactobacillus reuteri, there was consistency amongst findings (I² = 0%), but risk of bias was present in all included studies. Heterogeneity also was not explained by types of participants (age, nutritional/socioeconomic status captured by mortality stratum, region of the world where studies were undertaken), diarrhoea in children caused by rotavirus, exposure to antibiotics, and the few studies of children who were also treated with zinc. In addition, there were no clear differences in effect size for the primary outcomes in post hoc analyses according to decade of publication of studies and whether or not trials had been registered. For other outcomes, the duration of hospitalization in inpatient studies on average was shorter in probiotic groups than in control groups but there was marked heterogeneity between studies (I² = 96%; MD -18.03 hours, 95% CI -27.28 to -8.78, random-effects model: 24 trials, 4056 participants). No differences were detected between probiotic and control groups in the number of people with diarrhoea lasting ≥ 14 days (RR 0.49, 95% CI 0.16 to 1.53; 9 studies, 2928 participants) or in risk of hospitalization in community studies (RR 1.26, 95% CI 0.84 to 1.89; 6 studies, 2283 participants). No serious adverse events were attributed to probiotics.

AUTHORS' CONCLUSIONS

Probiotics probably make little or no difference to the number of people who have diarrhoea lasting 48 hours or longer, and we are uncertain whether probiotics reduce the duration of diarrhoea. This analysis is based on large trials with low risk of bias.

Bifidobacteriumlongum subsp. infantis CECT7210 (B. infantis IM-1®) Displays In Vitro Activity against Some Intestinal Pathogens

Certain non-digestible oligosaccharides (NDO) are specifically fermented by bifidobacteria along the human gastrointestinal tract, selectively favoring their growth and the production of health-promoting metabolites. In the present study, the ability of the probiotic strain Bifidobacterium longum subsp. infantis CECT7210 (herein referred to as B. infantis IM-1^®) to utilize a large range of oligosaccharides, or a mixture of oligosaccharides, was investigated. The strain was able to utilize all prebiotics screened. However, galactooligosaccharides (GOS), and GOS-containing mixtures, effectively increased its growth to a higher extent than the other prebiotics. The best synbiotic combination was used to examine the antimicrobial activity against Escherichia coli, Cronobacter sakazakii, Listeria monocytogenes and Clostridium difficile in co-culture experiments. C. difficile was inhibited by the synbiotic, but it failed to inhibit E. coli. Moreover, Cr. sakazakii growth decreased during co-culture with B. infantis IM-1^®. Furthermore, adhesion experiments using the intestinal cell line HT29 showed that the strain IM-1^® was able to displace some pathogens from the enterocyte layer, especially Cr. sakazakii and Salmonella enterica, and prevented the adhesion of Cr. sakazakii and Shigella sonnei. In conclusion, a new synbiotic (probiotic strain B. infantis IM-1^® and GOS) appears to be a potential effective supplement for maintaining infant health. However, further studies are needed to go more deeply into the mechanisms that allow B.infantis IM-1^® to compete with enteropathogens.

Bifidobacterium animalis ssp. Lactis 420 Mitigates Autoimmune Hepatitis Through Regulating Intestinal Barrier and Liver Immune Cells

Autoimmune hepatitis (AIH) is an immune-mediated inflammatory liver disease of uncertain cause. Accumulating evidence shows that gut microbiota and intestinal barrier play significant roles in AIH thus the gut–liver axis has important clinical significance as a potential therapeutic target. In the present study, we found that Bifidobacterium animalis ssp. lactis 420 (B420) significantly alleviated S100-induced experimental autoimmune hepatitis (EAH) and modulated the gut microbiota composition. While the analysis of clinical specimens revealed that the fecal SCFA quantities were decreased in AIH patients, and B420 increased the cecal SCFA quantities in EAH mice. Remarkably, B420 application improved intestinal barrier function through upregulation of tight junction proteins in both vitro and vivo experiments. Moreover, B420 decreased the serum endotoxin level and suppressed the RIP3 signaling pathway of liver macrophages in EAH mice thus regulated the proliferation of Th17 cells. Nevertheless, the inhibition effect of B420 on RIP3 signaling pathway was blunted in vitro studies. Together, our results showed that early intervention with B420 contributed to improve the liver immune homeostasis and liver injury in EAH mice, which might be partly due to the protection of intestinal barrier. Our study suggested the potential efficacy of probiotics application against AIH and the promising therapeutic strategies targeting gut–liver axis for AIH.

Probiotic Supplementation During the Perinatal and Infant Period: Effects on Gut Dysbiosis and Disease

The perinatal period is crucial to the establishment of lifelong gut microbiota. The abundance and composition of microbiota can be altered by several factors such as preterm delivery, formula feeding, infections, antibiotic treatment, and lifestyle during pregnancy. Gut dysbiosis affects the development of innate and adaptive immune responses and resistance to pathogens, promoting atopic diseases, food sensitization, and infections such as necrotizing enterocolitis (NEC). Recent studies have indicated that the gut microbiota imbalance can be restored after a single or multi-strain probiotic supplementation, especially mixtures of Lactobacillus and Bifidobacterium strains. Following the systematic search methodology, the current review addresses the importance of probiotics as a preventive or therapeutic tool for dysbiosis produced during the perinatal and infant period. We also discuss the safety of the use of probiotics in pregnant women, preterm neonates, or infants for the treatment of atopic diseases and infections.

Bifidobacterium longum Subspecies infantis (B. infantis) in Pediatric Nutrition: Current State of Knowledge

Abstract: Since originally isolated in 1899, the genus Bifidobacterium has been demonstrated to predominate in the gut microbiota of breastfed infants and to benefit the host by accelerating maturation of the immune response, balancing the immune system to suppress inflammation, improving intestinal barrier function, and increasing acetate production. In particular, Bifidobacterium longum subspecies infantis (B. infantis) is well adapted to the infant gut and has co-evolved with the mother-infant dyad and gut microbiome, in part due to its ability to consume complex carbohydrates found in human milk. B. infantis and its human host have a symbiotic relationship that protects the preterm or term neonate and nourishes a healthy gut microbiota prior to weaning. To provide benefits associated with B. infantis to all infants, a number of commercialized strains have been developed over the past decades. As new ingredients become available, safety and suitability must be assessed in preclinical and clinical studies. Consideration of the full clinical evidence for B. infantis use in pediatric nutrition is critical to better understand its potential impacts on infant health and development. Herein we summarize the recent clinical studies utilizing select strains of commercialized B. infantis.

Early-Life Gut Microbiome-The Importance of Maternal and Infant Factors in Its Establishment

The early-life microbiome is gaining appreciation as a major influencer in human development and long-term health. Multiple factors are known to influence the initial colonization, development, and function of the neonatal gut microbiome. In addition, alterations in early-life gut microbial composition is associated with several chronic health conditions such as obesity, asthma, and allergies. In this review, we focus on both maternal and infant factors known to influence early-life gut colonization. Also reviewed is the important role of infant feeding, including evidence-based strategies for maternal and infant supplementation with the goal to protect and/or restore the infant gut microbiome.

Construction of a Bioluminescent Labelling Plasmid Vector for Bifidobacteria

Bifidobacterium is recognized as one of the most beneficial microorganisms in our gut. Many researches on bifidobacteria have been done to understand their roles in the gut. The objective of the present study was to develop a bioluminescent labelling plasmid vector for bifidobacteria to facilitate their visualization in vitro, in situ, and in vivo. A plasmid replicon (2.0 kb) of plasmid pFI2576 previously identified from B. longum FI10564 was amplified by PCR and cloned into pUC19 plasmid vector (2.68 kb). The cloned replicon was subcloned into pTG262 (luc⁺) recombinant plasmid vector (7.4 kb) where a luciferase gene (luc⁺) from pLuc2 (8.5 kb), an Escherichia coli and lactobacilli shuttle vector, was inserted into pTG262 plasmid vector. The final recombinant DNA, pTG262::pFI2576 rep (luc⁺), was transferred into a B. catenulatum strain. This recombinant strain showed 3,024 relative luminescence units at OD₆₀₀ value of 0.352. Thus, this recombinant plasmid construct can be broadly used for labelling bifidobacteria.