Bifidobacterium infantis and 2'-fucosyllactose supplementation in early life may have potential long-term benefits on gut microbiota, intestinal development, and immune function in mice

The health benefits of nutritional interventions targeting the gut microbiota in early life are transient, such as probiotics, prebiotics, and synbiotics. This study sought to determine whether supplementation with Bifidobacterium infantis 79 (B79), 2'-fucosyllactose (2'-FL), or both (B79+2'FL) would lead to persistent health benefits in neonatal BALB/c mice. We found that at postnatal day (PND) 21, Ki67 and MUC2 expression increased, while total serum IgE content decreased in the B79, 2'-FL, and B79+2'-FL groups. The gut microbiota structure and composition altered as well. The levels of propionic acid, sIgA, and IL-10 increased in the 2'-FL group. Moreover, butyric acid content increased, while IL-6, IL-12p40, and tumor necrosis factor-α decreased in the B79+2'-FL group. At PND 56, Ki67 and MUC2 expression increased, whereas the gut microbiota remained altered in all 3 groups. The serum total IgG level increased only in the B79+2'-FL group. In conclusion, our study suggests that early-life supplementation with B79, 2'-FL, or their combination persistently alters the gut microbiome and promotes intestinal development; the immunomodulatory capacity of B79 and 2'-FL occurs during weaning, and their combination may persist into adulthood.

Relationship between Dietary Polyphenols and Gut Microbiota: New Clues to Improve Cognitive Disorders, Mood Disorders and Circadian Rhythms

Cognitive, mood and sleep disorders are common and intractable disorders of the central nervous system, causing great inconvenience to the lives of those affected. The gut-brain axis plays a vital role in studying neurological disorders such as neurodegenerative diseases by acting as a channel for a bidirectional information exchange between the gut microbiota and the nervous system. Dietary polyphenols have received widespread attention because of their excellent biological activity and their wide range of sources, structural diversity and low toxicity. Dietary intervention through the increased intake of dietary polyphenols is an emerging strategy for improving circadian rhythms and treating metabolic disorders. Dietary polyphenols have been shown to play an essential role in regulating intestinal flora, mainly by maintaining the balance of the intestinal flora and enhancing host immunity, thereby suppressing neurodegenerative pathologies. This paper reviewed the bidirectional interactions between the gut microbiota and the brain and their effects on the central nervous system, focusing on dietary polyphenols that regulate circadian rhythms and maintain the health of the central nervous system through the gut-brain axis.

Translating neonatal microbiome science into commercial innovation: metabolism of human milk oligosaccharides as a basis for probiotic efficacy in breast-fed infants

For over a century, physicians have witnessed a common enrichment of bifidobacteria in the feces of breast-fed infants that was readily associated with infant health status. Recent advances in bacterial genomics, metagenomics, and glycomics have helped explain the nature of this unique enrichment and enabled the tailored use of probiotic supplementation to restore missing bifidobacterial functions in at-risk infants. This review documents a 20-year span of discoveries that set the stage for the current use of human milk oligosaccharide-consuming bifidobacteria to beneficially colonize, modulate, and protect the intestines of at-risk, human milk-fed, neonates. This review also presents a model for probiotic applications wherein bifidobacterial functions, in the form of colonization and HMO-related catabolic activity in situ, represent measurable metabolic outcomes by which probiotic efficacy can be scored toward improving infant health.

Gut Microbiota and Cardiovascular System: An Intricate Balance of Health and the Diseased State

Gut microbiota encompasses the resident microflora of the gut. Having an intricate relationship with the host, it plays an important role in regulating physiology and in the maintenance of balance between health and disease. Though dietary habits and the environment play a critical role in shaping the gut, an imbalance (referred to as dysbiosis) serves as a driving factor in the occurrence of different diseases, including cardiovascular disease (CVD). With risk factors of hypertension, diabetes, dyslipidemia, etc., CVD accounts for a large number of deaths among men (32%) and women (35%) worldwide. As gut microbiota is reported to have a direct influence on the risk factors associated with CVDs, this opens up new avenues in exploring the possible role of gut microbiota in regulating the gross physiological aspects along the gut-heart axis. The present study elaborates on different aspects of the gut microbiota and possible interaction with the host towards maintaining a balance between health and the occurrence of CVDs. As the gut microbiota makes regulatory checks for these risk factors, it has a possible role in shaping the gut and, as such, in decreasing the chances of the occurrence of CVDs. With special emphasis on the risk factors for CVDs, this paper includes information on the prominent bacterial species (Firmicutes, Bacteriodetes and others) towards an advance in our understanding of the etiology of CVDs and an exploration of the best possible therapeutic modules for implementation in the treatment of different CVDs along the gut-heart axis.

Changes in intestinal parameters and their association with dietary patterns in rotational shift workers

Circadian rhythm disturbances induced by rotating shift work contribute to development of metabolic disorders. However, their effects on intestinal parameters such as epithelial permeability and fecal short chain fatty acid (SCFA) levels have not been established yet. This study was planned to investigate the changes in intestinal integrity, fecal SCFA levels, gut microbiota and nutritional intake of rotational shift workers. The study was conducted on ten male rotational shift workers, 25-40 years old. Circadian rhythm disruption was assumed to have occurred after 14 days in the night shift. Dietary data which was obtained by using 24 h record for 7 days, physical activity data, anthropometric measurements, fecal and blood samples were collected during day and night shift. Changes in dietary consumption, anthropometric measurements, blood chemistry and intestinal epithelial permeability indicator according to day and night shifts were not significant (p > .05). Additionally, acetic, propionic and total SCFA were associated with the intestinal permeability biomarker in night shift, but not in day shift (p < .05). Consumption of dark green vegetables and beans and peas was positively associated with fecal isobutyric acid and fecal total SCFA concentration (r = 0.685, p = .029; r = 0.695, p = .026, respectively). The proportions of the genus including Blautia, Bifidobacterium, Dialister, and Ruminococcus gnavus group increased when individuals shifted to the night shift. Gut microbiota changes responding to circadian rhythm disruption became more prominent when consumed high sugar diet. So, changes have been observed in the gut microbiota of rotational shift workers, especially in individuals with certain dietary pattern. Moreover, in individuals with the circadian rhythm disruption SCFAs levels have been demonstrated to be associated with intestinal barrier integrity. A better understanding of the relation among fecal SCFAs, gut microbiota, intestinal epithelial permeability and circadian rhythm disruption is necessary for the development of new dietary strategies for gut health.

Animal Models for Assessing Impact of C-Section Delivery on Biological Systems

There has been a significant increase in Caesarean section (C-section) births worldwide over the past two decades and although it is can be a life-saving procedure, the enduring effects on host physiology are now undergoing further scrutiny. Indeed, epidemiological data have linked C-section birth with multiple immune, metabolic and neuropsychiatric diseases. Birth by C-section is known to alter the colonisation of the neonatal gut microbiota (with C-section delivered infants lacking vaginal microbiota associated with passing along the birth canal), which in turn can impact the development and maintenance of many important biological systems. Appropriate animal models are key to disentangling the role of missing microbes in brain health and disease in C-section births. In this review of preclinical studies, we interrogate the effects of C-section birth on the development (and maintenance) of several biological systems and we discuss the involvement of the gut microbiome on C-section-related alterations.

Infant gut microbiota modulation by human milk disaccharides in humanized microbiome mice

Human milk glycans present a unique diversity of structures that suggest different mechanisms by which they may affect the infant microbiome development. A humanized mouse model generated by infant fecal transplantation was utilized here to evaluate the impact of fucosyl-α1,3-GlcNAc (3FN), fucosyl-α1,6-GlcNAc, lacto-N-biose (LNB) and galacto-N-biose on the fecal microbiota and host-microbiota interactions. 16S rRNA amplicon sequencing showed that certain bacterial genera significantly increased (Ruminococcus and Oscillospira) or decreased (Eubacterium and Clostridium) in all disaccharide-supplemented groups. Interestingly, cluster analysis differentiates the consumption of fucosyl-oligosaccharides from galactosyl-oligosaccharides, highlighting the disappearance of Akkermansia genus in both fucosyl-oligosaccharides. An increment of the relative abundance of Coprococcus genus was only observed with 3FN. As well, LNB significantly increased the relative abundance of Bifidobacterium, whereas the absolute levels of this genus, as measured by quantitative real-time PCR, did not significantly increase. OTUs corresponding to the species Bifidobacterium longum, Bifidobacterium adolescentis and Ruminococcus gnavus were not present in the control after the 3-week intervention, but were shared among the donor and specific disaccharide groups, indicating that their survival is dependent on disaccharide supplementation. The 3FN-feeding group showed increased levels of butyrate and acetate in the colon, and decreased levels of serum HDL-cholesterol. 3FN also down-regulated the pro-inflammatory cytokine TNF-α and up-regulated the anti-inflammatory cytokines IL-10 and IL-13, and the Toll-like receptor 2 in the large intestine tissue. The present study revealed that the four disaccharides show efficacy in producing beneficial compositional shifts of the gut microbiota and in addition, the 3FN demonstrated physiological and immunomodulatory roles.

Human Milk Oligosaccharides Reduce Murine Group B Streptococcus Vaginal Colonization with Minimal Impact on the Vaginal Microbiota

Group B Streptococcus (GBS) colonizes the vaginal mucosa of a significant percentage of healthy women and is a leading cause of neonatal bacterial infections. Currently, pregnant women are screened in the last month of pregnancy, and GBS-positive women are given antibiotics during parturition to prevent bacterial transmission to the neonate. Recently, human milk oligosaccharides (HMOs) isolated from breastmilk were found to inhibit GBS growth and biofilm formation in vitro, and women that make certain HMOs are less likely to be vaginally colonized with GBS. Using in vitro human vaginal epithelial cells and a murine vaginal colonization model, we tested the impact of HMO treatment on GBS burdens and the composition of the endogenous microbiota by 16S rRNA amplicon sequencing. HMO treatment reduced GBS vaginal burdens in vivo with minimal alterations to the vaginal microbiota. HMOs displayed potent inhibitory activity against GBS in vitro, but HMO pretreatment did not alter adherence of GBS or the probiotic Lactobacillus rhamnosus to human vaginal epithelial cells. In addition, disruption of a putative GBS glycosyltransferase (Δsan_0913) rendered the bacterium largely resistant to HMO inhibition in vitro and in vivo but did not compromise its adherence, colonization, or biofilm formation in the absence of HMOs. We conclude that HMOs are a promising therapeutic bioactive to limit GBS vaginal colonization with minimal impacts on the vaginal microenvironment.

IMPORTANCE During pregnancy, GBS ascension into the uterus can cause fetal infection or preterm birth. In addition, GBS exposure during labor creates a risk of serious disease in the vulnerable newborn and mother postpartum. Current recommended prophylaxis consists of administering broad-spectrum antibiotics to GBS-positive mothers during labor. Although antibiotics have significantly reduced GBS neonatal disease, there are several unintended consequences, including altered neonatal gut bacteria and increased risk for other types of infection. Innovative preventions displaying more targeted antimicrobial activity, while leaving the maternal microbiota intact, are thus appealing. Using a mouse model, we found that human milk oligosaccharides (HMOs) reduce GBS burdens without perturbing the vaginal microbiota. We conclude that HMOs are a promising alternative to antibiotics to reduce GBS neonatal disease.

Evaluation of 2'-Fucosyllactose and Bifidobacterium longum Subspecies infantis on Growth, Organ Weights, and Intestinal Development of Piglets

Human milk is rich in oligosaccharides that influence intestinal development and serve as prebiotics for the infant gut microbiota. Probiotics and 2’-fucosyllactose (2’-FL) added individually to infant formula have been shown to influence infant development, but less is known about the effects of their synbiotic administration. Herein, the impact of formula supplementation with 2’-fucosyllactose (2’-FL) and Bifidobacterium longum subsp. infantis Bi-26 (Bi-26), or 2’-FL + Bi-26 on weight gain, organ weights, and intestinal development in piglets was investigated. Two-day-old piglets (n = 53) were randomized in a 2 × 2 design to be fed a commercial milk replacer ad libitum without (CON) or with 1.0 g/L 2’-FL. Piglets in each diet were further randomized to receive either glycerol stock alone or Bi-26 (10⁹ CFU) orally once daily. Body weights and food intake were monitored from postnatal day (PND) 2 to 33/34. On PND 34/35, animals were euthanized and intestine, liver and brain weights were assessed. Intestinal samples were collected for morphological analyses and measurement of disaccharidase activity. Dry matter of cecum and colon contents and Bifidobacterium longum subsp. infantis abundance by RT-PCR were also measured. All diets were well tolerated, and formula intake did not differ among the treatment groups. Daily body weights were affected by 2’-FL, Bi-26, and day, but no interaction was observed. There was a trend (p = 0.075) for greater total body weight gain in CON versus all other groups. Jejunal and ascending colon histomorphology were unaffected by treatment; however, there were main effects of 2’-FL to increase (p = 0.040) and Bi-26 to decrease (p = 0.001) ileal crypt depth. The addition of 2’-FL and/or Bi-26 to milk replacer supported piglet growth with no detrimental effects on body and organ weights, or intestinal structure and function.

Short-chain fatty acids-producing probiotics: A novel source of psychobiotics

Psychobiotics-live microorganisms with potential mental health benefits, which can modulate the microbiota-gut-brain-axis via immune, humoral, neural, and metabolic pathways-are emerging as novel therapeutic options for the effective treatment of psychiatric disorders Recently, microbiome studies have identified numerous putative psychobiotic strains, of which short-chain fatty acids (SCFAs) producing bacteria have attracted special attention from neurobiologists. Recent studies have highlighted that SCFAs-producing bacteria such as Lactobacillus, Bifidobacterium and Clostridium have a very specific function in various psychiatric disorders, suggesting that these bacteria can be potential novel psychobiotics. SCFAs, potential mediators of microbiota-gut-brain axis, might modulate function of neurological processes. While the specific roles and mechanisms of SCFAs-producing bacteria of microbiota-targeted interventions on neuropsychiatric disease are largely unknown. This Review summarizes existing knowledge on the neuroprotective effects of the SCFAs-producing bacteria in neurological disorders via modulating microbiota-gut-brain axis and illustrate their possible mechanisms by which SCFAs-producing bacteria may act on these disorders, which will shed light on the SCFAs-producing bacteria as a promising novel source of psychobiotics.

Faecalibacterium prausnitzii: A Next-Generation Probiotic in Gut Disease Improvement

The researchers are paying more attention to the role of gut commensal bacteria in health development beyond the classical pathogens. It has been widely demonstrated that dysbiosis, which means the alternations of the gut microbial structure, is closely associated with development of intestinal chronic inflammation-related diseases such as inflammatory bowel disease (IBD), and even infectious diseases including bacterial and viral infection. Thus, for reshaping ecological balance, a growing body of the literatures have proposed numerous strategies to modulate the structure of the gut microbiota, which provide more revelation for amelioration of these inflammation or infection-related diseases. While the ameliorative effects of traditional probiotics seem negligeable, emerging next generation probiotics (NGPs) start to receive great attention as new preventive and therapeutic tools. Encouragingly, within the last decade, the intestinal symbiotic bacterium Faecalibacterium prausnitzii has emerged as the “sentinel of the gut,” with multifunction of anti-inflammation, gut barrier enhancement, and butyrate production. A lower abundance of F. prausnitzii has been shown in IBD, Clostridium difficile infection (CDI), and virus infection such as COVID-19. It is reported that intervention with higher richness of F. prausnitzii through dietary modulation, fecal microbiota transplantation, or culture strategy can protect the mice or the subjects from inflammatory diseases. Therefore, F. prausnitzii may have potential ability to reduce microbial translocation and inflammation, preventing occurrences of gastrointestinal comorbidities especially in COVID-19 patients.

Comparison of Two Approaches for the Metataxonomic Analysis of the Human Milk Microbiome

Recent work has demonstrated the existence of large inter-individual and inter-population variability in the microbiota of human milk from healthy women living across variable geographical and socio-cultural settings. However, no studies have evaluated the impact that variable sequencing approaches targeting different 16S rRNA variable regions may have on the human milk microbiota profiling results. This hampers our ability to make meaningful comparisons across studies. In this context, the main purpose of the present study was to re-process and re-sequence the microbiome in a large set of human milk samples (n = 412) collected from healthy women living at diverse international sites (Spain, Sweden, Peru, United States, Ethiopia, Gambia, Ghana and Kenya), by targeting a different 16S rRNA variable region and reaching a larger sequencing depth. Despite some differences between the results obtained from both sequencing approaches were notable (especially regarding alpha and beta diversities and Proteobacteria representation), results indicate that both sequencing approaches revealed a relatively consistent microbiota configurations in the studied cohorts. Our data expand upon the milk microbiota results we previously reported from the INSPIRE cohort and provide, for the first time across globally diverse populations, evidence of the impact that different DNA processing and sequencing approaches have on the microbiota profiles obtained for human milk samples. Overall, our results corroborate some similarities regarding the microbial communities previously reported for the INSPIRE cohort, but some differences were also detected. Understanding the impact of different sequencing approaches on human milk microbiota profiles is essential to enable meaningful comparisons across studies.

Clinical Trial Registration

www.clinicaltrials.gov, identifier NCT02670278.

In Love with Shaping You-Influential Factors on the Breast Milk Content of Human Milk Oligosaccharides and Their Decisive Roles for Neonatal Development

Human milk oligosaccharides (HMOs) are structurally versatile sugar molecules constituting the third major group of soluble components in human breast milk. Based on the disaccharide lactose, the mammary glands of future and lactating mothers produce a few hundreds of different HMOs implicating that their overall anabolism utilizes rather high amounts of energy. At first sight, it therefore seems contradictory that these sugars are indigestible for infants raising the question of why such an energy-intensive molecular class evolved. However, in-depth analysis of their molecular modes of action reveals that Mother Nature created HMOs for neonatal development, protection and promotion of health. This is not solely facilitated by HMOs in their indigestible form but also by catabolites that are generated by microbial metabolism in the neonatal gut additionally qualifying HMOs as natural prebiotics. This narrative review elucidates factors influencing the HMO composition as well as physiological roles of HMOs on their way through the infant body and within the gut, where a major portion of HMOs faces microbial catabolism. Concurrently, this work summarizes in vitro, preclinical and observational as well as interventional clinical studies that analyzed potential health effects that have been demonstrated by or were related to either human milk-derived or synthetic HMOs or HMO fractions.

Gut-Brain Axis: Role of Gut Microbiota on Neurological Disorders and How Probiotics/Prebiotics Beneficially Modulate Microbial and Immune Pathways to Improve Brain Functions

The gut microbiome acts as an integral part of the gastrointestinal tract (GIT) that has the largest and vulnerable surface with desirable features to observe foods, nutrients, and environmental factors, as well as to differentiate commensals, invading pathogens, and others. It is well-known that the gut has a strong connection with the central nervous system (CNS) in the context of health and disease. A healthy gut with diverse microbes is vital for normal brain functions and emotional behaviors. In addition, the CNS controls most aspects of the GI physiology. The molecular interaction between the gut/microbiome and CNS is complex and bidirectional, ensuring the maintenance of gut homeostasis and proper digestion. Besides this, several mechanisms have been proposed, including endocrine, neuronal, toll-like receptor, and metabolites-dependent pathways. Changes in the bidirectional relationship between the GIT and CNS are linked with the pathogenesis of gastrointestinal and neurological disorders; therefore, the microbiota/gut-and-brain axis is an emerging and widely accepted concept. In this review, we summarize the recent findings supporting the role of the gut microbiota and immune system on the maintenance of brain functions and the development of neurological disorders. In addition, we highlight the recent advances in improving of neurological diseases by probiotics/prebiotics/synbiotics and fecal microbiota transplantation via the concept of the gut-brain axis.

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.

Causal Relationship between Diet-Induced Gut Microbiota Changes and Diabetes: A Novel Strategy to Transplant Faecalibacterium prausnitzii in Preventing Diabetes

The incidence of metabolic disorders, including diabetes, has elevated exponentially during the last decades and enhanced the risk of a variety of complications, such as diabetes and cardiovascular diseases. In the present review, we have highlighted the new insights on the complex relationships between diet-induced modulation of gut microbiota and metabolic disorders, including diabetes. Literature from various library databases and electronic searches (ScienceDirect, PubMed, and Google Scholar) were randomly collected. There exists a complex relationship between diet and gut microbiota, which alters the energy balance, health impacts, and autoimmunity, further causes inflammation and metabolic dysfunction, including diabetes. Faecalibacterium prausnitzii is a butyrate-producing bacterium, which plays a vital role in diabetes. Transplantation of F. prausnitzii has been used as an intervention strategy to treat dysbiosis of the gut’s microbial community that is linked to the inflammation, which precedes autoimmune disease and diabetes. The review focuses on literature that highlights the benefits of the microbiota especially, the abundant of F. prausnitzii in protecting the gut microbiota pattern and its therapeutic potential against inflammation and diabetes.