Why is initial bacterial colonization of the intestine important to infants' and children's health?

The Infant Gut Microbiota and Risk of Asthma: The Effect of Maternal Nutrition during Pregnancy and Lactation

Research has amply demonstrated that early life dysbiosis of the gut microbiota influences the propensity to develop asthma. The influence of maternal nutrition on infant gut microbiota is therefore of growing interest. However, a handful of prospective studies have examined the role of maternal dietary patterns during pregnancy in influencing the infant gut microbiota but did not assess whether this resulted in an increased risk of asthma later in life. The mechanisms involved in the process are also, thus far, poorly documented. There have also been few studies examining the effect of maternal dietary nutrient intake during lactation on the milk microbiota, the effect on the infant gut microbiota and, furthermore, the consequences for asthma development remain largely unknown. Therefore, the specific aim of this mini review is summarizing the current knowledge regarding the effect of maternal nutrition during pregnancy and lactation on the infant gut microbiota composition, and whether it has implications for asthma development.

Maternal sensitivity and mother-infant attachment are associated with antibiotic uptake in infancy

Attachment security has been associated with health status and symptom reporting. In this longitudinal study, we investigated the association between antibiotics uptake by infants at 9-months and mother-infant attachment at 12-months. Logistic regression analyses indicated that lower maternal sensitivity was associated with increased odds of antibiotic uptake. Furthermore, 89.7% of insecure-ambivalent infants consumed antibiotics, which contrasted with 32.5% of avoidant infants and 21.5% of secure infants. This study suggests that maternal behavior and mother-infant attachment impact on antibiotic consumption, which is worrying because antibiotics may lead to several health problems later in life and antibiotic-resistance.

Prebiotic Properties of Non-Fructosylated α-Galactooligosaccharides from PEA (Pisum sativum L.) Using Infant Fecal Slurries

The interest for naturally-occurring oligosaccharides from plant origin having prebiotic properties is growing, with special focus being paid to supplemented products for infants. Currently, non-fructosylated α-galactooligosaccharides (α-GOS) from peas have peaked interest as a result of their prebiotic activity in adults and their mitigated side-effects on gas production from colonic bacterial fermentation. In this study, commercially available non-fructosylated α-GOS from peas and β-galactooligosaccharides (β-GOS) derived from lactose were fermented using fecal slurries from children aged 11 to 24 months old during 6 and 24 h. The modulatory effect of both GOS on different bacterial groups and bifidobacteria species was assessed; non-fructosylated α-GOS consumption was monitored throughout the fermentation process and the amounts of lactic acid and short-chain fatty acids (SCFA) generated were analyzed. Non-fructosylated α-GOS, composed mainly of manninotriose and verbascotetraose and small amounts of melibiose, were fully metabolized and presented remarkable bifidogenic activity, similar to that obtained with β-GOS. Furthermore, non-fructosylated α-GOS selectively caused an increase on the population of Bifidobacterium longum subsp. longum and Bifidobacterium catenulatum/pseudo-catenulatum. In conclusion, non-fructosylated α-GOS could be used as potential ingredient in infant formula supplemented with prebiotic oligosaccharides.

Incidence of necrotising enterocolitis before and after introducing routine prophylactic Lactobacillus and Bifidobacterium probiotics

OBJECTIVE

To compare rates of necrotising enterocolitis (NEC), late-onset sepsis, and mortality in 5-year epochs before and after implementation of routine daily multistrain probiotics administration in high-risk neonates.

DESIGN

Single-centre retrospective observational study over the 10-year period from 1 January 2008 to 31 December 2017.

SETTING

Level 3 neonatal intensive care unit (NICU) of the Norfolk and Norwich University Hospital, UK.

PATIENTS

Preterm neonates at high risk of NEC: admitted to NICU within 3 days of birth at <32 weeks' gestation or at 32-36 weeks' gestation and of birth weight <1500 g.

INTERVENTION

Prior to 1 January 2013 probiotics were not used. Thereafter, dual-species Lactobacillus acidophilus and Bifidobacterium bifidum combination probiotics were routinely administered daily to high-risk neonates; from April 2016 triple-species probiotics (L. acidophilus, B. bifidum, and B. longum subspecies infantis) were used.

MAIN OUTCOME MEASURES

Incidence of NEC (modified Bell's stage 2a or greater), late-onset sepsis, and mortality.

RESULTS

Rates of NEC fell from 7.5% (35/469 neonates) in the pre-implementation epoch to 3.1% (16/513 neonates) in the routine probiotics epoch (adjusted sub-hazard ratio=0.44, 95% CI 0.23 to 0.85, p=0.014). The more than halving of NEC rates after probiotics introduction was independent of any measured covariates, including breast milk feeding rates. Cases of late-onset sepsis fell from 106/469 (22.6%) to 59/513 (11.5%) (p<0.0001), and there was no episode of sepsis due to Lactobacillus or Bifidobacterium. All-cause mortality also fell in the routine probiotics epoch, from 67/469 (14.3%) to 47/513 (9.2%), although this was not statistically significant after multivariable adjustment (adjusted sub-hazard ratio=0.74, 95% CI 0.49 to 1.12, p=0.155).

CONCLUSIONS

Administration of multispecies Lactobacillus and Bifidobacterium probiotics has been associated with a significantly decreased risk of NEC and late-onset sepsis in our neonatal unit, and no safety issues. Our data are consistent with routine use of Lactobacillus and Bifidobacterium combination probiotics having a beneficial effect on NEC prevention in very preterm neonates.

The Lovebug Effect: Is the human biophilic drive influenced by interactions between the host, the environment, and the microbiome?

Psychological frameworks are often used to investigate the mechanisms involved with our affinity towards, and connection with nature--such as the Biophilia Hypothesis and Nature Connectedness. Recent revelations from microbiome science suggest that animal behaviour can be strongly influenced by the host's microbiome--for example, via the bidirectional communication properties of the gut-brain axis. Here, we build on this theory to hypothesise that a microbially-influenced mechanism could also contribute to the human biophilic drive - the tendency for humans to affiliate and connect with nature. Humans may be at an evolutionary advantage through health-regulating exchange of environmental microbiota, which in turn could influence our nature affinity. We present a conceptual model for microbially-influenced nature affinity, calling it the Lovebug Effect. We present an overview of the potential mechanistic pathways involved in the Lovebug Effect, and consider its dependence on the hologenome concept of evolution, direct behavioural manipulation, and host-microbiota associated phenotypes independent of these concepts. We also discuss its implications for human health and ecological resilience. Finally, we highlight several possible approaches to scrutinise the hypothesis. The Lovebug Effect could have important implications for our understanding of exposure to natural environments for health and wellbeing, and could contribute to an ecologically resilient future.

Breastfeeding may have a long-term effect on oral microbiota: results from the Fin-HIT cohort

BACKGROUND

Breastfeeding contributes to gastrointestinal microbiota colonization in early life, but its long-term impact is inconclusive. We aimed to evaluate whether the type of feeding during the first six months of life was associated with oral microbiota in adolescence.

METHODS

This is a cross-sectional sub-study using baseline information of 423 adolescents from the Finnish Health in Teens (Fin-HIT) cohort. Type of feeding was recalled by parents and dichotomized as (i) No infant formula; (ii) Infant formula (breastmilk + formula or only formula). Saliva microbiota was analysed using 16S rRNA (V3-V4) sequencing. Alpha diversity and beta diversity were compared between feeding type groups using ANCOVA and PERMANOVA, respectively. Differential bacteria abundance was tested using appropriate general linear models.

RESULTS

Mean age and body mass index were 11.7 years and 18.0 kg/m2, respectively. The No formula group contained 41% of the participants. Firmicutes (51.0%), Bacteroidetes (19.1%), and Proteobacteria (16.3%) were the most abundant phyla among all participants. Alpha and beta diversity indices did not differ between the two feeding groups. Three Operational Taxonomic Units (OTUs) belonging to Eubacteria and Veillonella genera (phylum Firmicutes) were more abundant in the No formula than in the Infant formula group (log2fold changes/ p - values - 0.920/ < 0.001, - 0.328/ 0.001, - 0.577/ 0.004).

CONCLUSION

Differences exist in abundances of some OTUs in adolescence according to feeding type during the first six months of life, but our findings do not support diversity and overall oral microbiota composition in adolescents being affected by early feeding type.

Dietary intake from complementary feeding is associated with intestinal barrier function and environmental enteropathy in Brazilian children from the MAL-ED cohort study

A child's diet contains nutrients and other substances that influence intestinal health. The present study aimed to evaluate the relations between complementary feeding, intestinal barrier function and environmental enteropathy (EE) in infants. Data from 233 children were obtained from the Brazilian site of the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project cohort study. Habitual dietary intake from complementary feeding was estimated using seven 24-h dietary recalls, from 9 to 15 months of age. Intestinal barrier function was assessed using the lactulose-mannitol test (L-M), and EE was determined as a composite measure using faecal biomarkers concentrations - α-1-antitrypsin, myeloperoxidase (MPO) and neopterin (NEO) at 15 months of age. The nutrient adequacies explored the associations between dietary intake and the intestinal biomarkers. Children showed adequate nutrient intakes (with the exception of fibre), impaired intestinal barrier function and intestinal inflammation. There was a negative correlation between energy adequacy and L-M (ρ = -0·19, P < 0·05) and between folate adequacy and NEO concentrations (ρ = -0·21, P < 0·01). In addition, there was a positive correlation between thiamine adequacy and MPO concentration (ρ = 0·22, P < 0·01) and between Ca adequacy and NEO concentration (ρ = 0·23; P < 0·01). Multiple linear regression models showed that energy intakes were inversely associated with intestinal barrier function (β = -0·19, P = 0·02), and fibre intake was inversely associated with the EE scores (β = -0·20, P = 0·04). Findings suggest that dietary intake from complementary feeding is associated with decreased intestinal barrier function and EE in children.

Sleep, circadian rhythm, and gut microbiota

From asthma and heart disease to diabetes and obesity, the human microbiome plays a role in the pathogenesis of each chronic health condition plaguing today's society. Recent work has shown that the gut microbiota and its metabolites exhibit diurnal rhythmicity which predominantly respond to the feeding/fasting cycle. Persistent jet lag, an obesogenic diet, and clock gene deficiency can dampen the oscillatory nature of gut bacterial composition, which can subsequently be rescued by time restricted feeding. Contrastingly, gut microbial metabolites influence central and hepatic clock gene expression and sleep duration in the host and regulate body composition through circadian transcription factors. Both sleep fragmentation and short sleep duration are associated with gut dysbiosis which may be due to activation of the HPA-axis. Metabolic disturbances associated with sleep loss may in fact be mediated through the overgrowth of specific gut bacteria. Reciprocally, the end products of bacterial species which grow in response to sleep loss are able to induce fatigue. Furthermore, probiotic supplementation has been found to improve subjective sleep quality. Sleep quality and duration may be an important target for supporting healthy gut microbiota composition, but the cyclic nature of this relationship should not be overlooked.

Feeding the preterm infant: an overview of the evidence

Feeding from own mother's milk is not always an option for preterm infants, and choosing between alternative means of feeding should be made in light of their effect on infants' health. In this work, we aimed to present evidence regarding feeding pre-term infants with human milk, either own mother's or donor milk (DM), and the potential effects on growth and other health related outcomes. Exclusive breastfeeding (BF) remains the optimal option, whereas feeding with DM as a sole diet or supplemental to maternal milk confers immunological advantages and fewer rates of necrotising enterocolitis against preterm formula feeding, yet the latter results in greater growth velocity. Literature gaps in the use of DM, practical suggestions for choosing suitable feeding means (i.e. continuous support of BF, adequate education regarding feeding preterm infants, including DM), and future perspectives on the potential effects of dietary manipulations of the maternal diet, are also discussed.

Allergy development is associated with consumption of breastmilk with a reduced microbial richness in the first month of life

BACKGROUND

Early colonization with a diverse microbiota seems to play a crucial role for appropriate immune maturation during childhood. Breastmilk microbiota is one important source of microbes for the infant, transferred together with maternal IgA antibodies. We previously observed that allergy development during childhood was associated with aberrant IgA responses to the gut microbiota already at 1 month of age, when the IgA antibodies are predominantly maternally derived in breastfed infants.

OBJECTIVE

To determine the microbial composition and IgA-coated bacteria in breastmilk in relation to allergy development in children participating in an intervention trial with pre- and post-natal Lactobacillus reuteri supplementation.

METHODS

A combination of flow cytometric cell sorting and 16S rRNA gene sequencing was used to characterize the bacterial recognition patterns by IgA in breastmilk samples collected one month post-partum from 40 mothers whose children did or did not develop allergic and asthmatic symptoms during the first 7 years of age.

RESULTS

The milk fed to children developing allergic manifestations had significantly lower bacterial richness, when compared to the milk given to children that remained healthy. Probiotic treatment influenced the breastmilk microbiota composition. However, the proportions of IgA-coated bacteria, the total bacterial load and the patterns of IgA-coating were similar in breastmilk between mothers of healthy children and those developing allergies.

CONCLUSION

Consumption of breastmilk with a reduced microbial richness in the first month of life may play an important role in allergy development during childhood.

Relationship between Breastfeeding, Birth History, and Acute Pyelonephritis in Infants

BACKGROUND

Although the clinical importance of the immunological benefits of breastfeeding has been emphasized for decades, their direct relationship with acute pyelonephritis (APN) is still not clear. Our goal was to determine whether breastfeeding truly provides protection against APNs, while investigating the effects of other factors such as sex, age, mode of delivery, and birth weight on APN.

METHODS

A total of 62 infants under 6 months of age who had both microbiologically and radiologically-confirmed APN were enrolled in the case group. Healthy infants (n = 178) who visited the hospital for scheduled vaccinations were enrolled in the control group. The following participant characteristics were compared between the case and control groups: age, sex, birth order among siblings, feeding methods, weight percentile by month, birth weight percentile by gestational age, gestational age at birth, and mode of delivery.

RESULTS

Babies exclusively fed with manufactured infant formulae before 6 months of age had significantly higher risk for APN than breastfed or mixed-fed infants (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.687-7.031; P = 0.001). Firstborn babies had lower risk for APN than 2nd- or 3rd-born babies (OR, 0.43; 95% CI, 0.210-0.919). Other factors that increased the risk for APN were low birth weight percentiles (OR, 8.33; 95% CI, 2.300-30.166) and birth via caesarean section (OR, 2.32; 95% CI, 1.097-4.887). There were more preterm births in the case group (10.9% vs. 1.7%; P = 0.002), but this did not increase the risk for APN (OR, 4.47; P = 0.063).

CONCLUSION

Feeding exclusively with formula before 6 months of age was related to higher risk for APN, which demonstrates that breastfeeding has a protective effect against APN. The other risk factors for APN were birth order (≥ 2nd-born), low birth weight, and birth via caesarean section.

Impacts of Prebiotic-Supplemented Diets and Breastmilk on Population and Diversity of Lactobacilli Established in Thai Healthy Infants

The relative abundance and diversity of lactobacilli present in feces of infants fed with breastmilk and fructooligosaccharide-galactooligosaccharide (FOS-GOS)-, and inulin-galactooligosaccharide (inulin-GOS)-supplemented infant formulae and combination of both were compared. Fecal lactobacilli rapidly colonized and reached maximum total cell counts, which were significantly higher in the infants fed by combining breastmilk with a formula containing either FOS-GOS (C1-A infant) or inulin-GOS (C2-C infant) and the exclusively formula fed ones (F1-F and F2-H infants) than those detected in the exclusively breast-fed (B1-D and B2-E infants) (P < 0.05). The greatest relative abundance of fecal lactobacilli species was observed in all infant receiving prebiotic-containing diets, whereas bifidobacteria appeared predominantly in exclusively breast-fed infants. The species composition of lactobacilli was highly unique among individual and more variable in both groups of infants receiving breastmilk than the exclusively formula-fed infants. Breastmilk seem to be a great source of indigenous lactobacilli vertically transferred and continuously seeded infants' gut. Meanwhile, prebiotic supplementation in infant formulae enhanced and sustained the successful colonization of lactobacilli.

The infant gut microbiome as a microbial organ influencing host well-being

Initial establishment of the human gut microbiota is generally believed to occur immediately following birth, involving key gut commensals such as bifidobacteria that are acquired from the mother. The subsequent development of this early gut microbiota is driven and modulated by specific dietary compounds present in human milk that support selective colonization. This represents a very intriguing example of host-microbe co-evolution, where both partners are believed to benefit. In recent years, various publications have focused on dissecting microbial infant gut communities and their interaction with their human host, being a determining factor in host physiology and metabolic activities. Such studies have highlighted a reduction of microbial diversity and/or an aberrant microbiota composition, sometimes referred to as dysbiosis, which may manifest itself during the early stage of life, i.e., in infants, or later stages of life. There are growing experimental data that may explain how the early human gut microbiota affects risk factors related to adult health conditions. This concept has fueled the development of various nutritional strategies, many of which are based on probiotics and/or prebiotics, to shape the infant microbiota. In this review, we will present the current state of the art regarding the infant gut microbiota and the role of key commensal microorganisms like bifidobacteria in the establishment of the first microbial communities in the human gut.

Maternal-neonatal transmission of Enterococcus strains during delivery

Background

Cesarean delivery (c-section) is on the rise globally. C-section is generally preferred if complications prevail in a vaginal delivery. Some private institutions conduct it unnecessarily for economic gains. This has led to a severe risk to a child’s health. The neonate’s gut microbiota has been observed to be influenced by the mode of delivery. Lactobacilli and other bacteria are very vital for developing healthy gut flora. An attempt has been made to investigate the passage of lactic acid bacteria to the infant via delivery. The vaginal swabs of the mothers and fresh meconium samples of the newborns post-delivery were examined for the presence of lactobacilli through culture techniques.

Results

The present investigation revealed that c-section-delivered infants lacked these bacteria in comparison with vaginally delivered infants. Biochemical tests and 16S rRNA sequencing showed similarity with groups 1, 2, 3, and 5 of Enterococcus genus. Phylogenetic analysis revealed more than 98% similarity with several Enterococcus species. E. canintestini, E.rivorum, and E. dispar were transferred frequently from mother to infants born via vaginal delivery. The strains were submitted to the NCBI GenBank database under accession numbers KX830968–KX830982.

Conclusion

The study supports the hypothesis of maternal-neonatal transmission of bacteria during delivery and also possibilities of isolating newer strains for probiotic use.

Hepcidin mediates hypoferremia and reduces the growth potential of bacteria in the immediate post-natal period in human neonates

Septicemia is a leading cause of death among neonates in low-income settings, a situation that is deteriorating due to high levels of antimicrobial resistance. Novel interventions are urgently needed. Iron stimulates the growth of most bacteria and hypoferremia induced by the acute phase response is a key element of innate immunity. Cord blood, which has high levels of hemoglobin, iron and transferrin saturation, has hitherto been used as a proxy for the iron status of neonates. We investigated hepcidin-mediated redistribution of iron in the immediate post-natal period and tested the effect of the observed hypoferremia on the growth of pathogens frequently associated with neonatal sepsis. Healthy, vaginally delivered neonates were enrolled in a cohort study at a single center in rural Gambia (N = 120). Cord blood and two further blood samples up to 96 hours of age were analyzed for markers of iron metabolism. Samples pooled by transferrin saturation were used to conduct ex-vivo growth assays with Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli and Klebsiella pneumonia. A profound reduction in transferrin saturation occurred within the first 12 h of life, from high mean levels in cord blood (47.6% (95% CI 43.7–51.5%)) to levels at the lower end of the normal reference range by 24 h of age (24.4% (21.2–27.6%)). These levels remained suppressed to 48 h of age with some recovery by 96 h. Reductions in serum iron were associated with high hepcidin and IL-6 levels. Ex-vivo growth of all sentinel pathogens was strongly associated with serum transferrin saturation. These results suggest the possibility that the hypoferremia could be augmented (e.g. by mini-hepcidins) as a novel therapeutic option that would not be vulnerable to antimicrobial resistance. Trial registration: The original trial in which this study was nested is registered at ISRCTN, number 93854442.

The role of the brain-gut-microbiota axis in psychology: The importance of considering gut microbiota in the development, perpetuation, and treatment of psychological disorders

INTRODUCTION

The prevalence of psychological disorders remains stable despite steady increases in pharmacological treatments suggesting the need for auxiliary treatment options. Consideration of the brain-gut-microbiota axis (BGMA) has made inroads into reconceptualizing psychological illness from a more holistic perspective. While our understanding of the precise role of gut microbiota (GM) in psychological illness is in its infancy, it represents an attractive target for novel interventions.

METHOD

An extensive review of relevant literature was undertaken.

RESULTS

Gut microbiota are proposed to directly and indirectly influence mood, cognition, and behavior which are key components of mental health. This paper outlines how GM may be implicated in psychological disorders from etiology through to treatment and prevention using the Four P model of case formulation.

CONCLUSION

Moving forward, integration of GM into the conceptualization and treatment of psychological illness will require the discipline of psychology to undergo a significant paradigm shift. While the importance of the GM in psychological well-being must be respected, it is not proposed to be a panacea, but instead, an additional arm to a multidisciplinary approach to treatment and prevention.

Neonatal iron distribution and infection susceptibility in full term, preterm and low birthweight babies in urban Gambia: study protocol for an observational study

Background: Neonatal infection is the third largest cause of death in children under five worldwide.  Nutritional immunity is the process by which the host innate immune system limits nutrient availability to invading organisms. Iron is an essential micronutrient for both microbial pathogens and their mammalian hosts. Changes in iron availability and distribution have significant effects on pathogen virulence and on the immune response to infection. Our previously published data shows that, during the first 24 hours of life, full-term neonates have reduced overall serum iron. Transferrin saturation decreases rapidly from 45% in cord blood to ~20% by six hours post-delivery. Methods: To study neonatal nutritional immunity and its role in neonatal susceptibility to infection, we will conduct an observational study on 300 full-term normal birth weight (FTB+NBW), 50 preterm normal birth weight (PTB+NBW), 50 preterm low birth weight (PTB+LBW) and 50 full-term low birth weight (FTB+LBW), vaginally-delivered neonates born at Kanifing General Hospital, The Gambia. We will characterize and quantify iron-related nutritional immunity during the early neonatal period and use ex vivo sentinel bacterial growth assays to assess how differences in serum iron affect bacterial growth. Blood samples will be collected from the umbilical cord (arterial and venous) and at serial time points from the neonates over the first week of life. Discussion: Currently, little is known about nutritional immunity in neonates. In this study, we will increase understanding of how nutritional immunity may protect neonates from infection during the first critical days of life by limiting the pathogenicity and virulence of neonatal sepsis causing organisms by reducing the availability of iron. Additionally, we will investigate the hypothesis that this protective mechanism may not be activated in preterm and low birth weight neonates, potentially putting these babies at an enhanced risk of neonatal infection. Trial registration: clinicaltrials.gov ( NCT03353051) 27/11/2017.

Influence of Leptin and Adiponectin Supplementation on Intraepithelial Lymphocyte and Microbiota Composition in Suckling Rats

Dietary components in early life play a role in both microbiota and intestinal immune system maturation in mammalian species. Adipokines, as endogenously produced hormones from breast milk, may have an impact on this process. The aim of the present study was to establish the influence of leptin and adiponectin supplementation during suckling on the intraepithelial lymphocyte composition, intestinal barrier function, intestinal gene expression, and gut microbiota in rat. For this purpose, newborn Wistar rats were supplemented daily with leptin, adiponectin, or whey protein concentrate during the first 21 days of life. Lymphocyte composition was established by immunofluorescence staining and flow cytometry analysis; intestinal gene expression by real-time PCR and cecal microbiota were analyzed through 16S rRNA gene sequencing. Although leptin and adiponectin were able to increase the Tc TCRαβ⁺ and NKT cell proportion, they decreased the NK cell percentage in IEL. Moreover, adipokine supplementation differentially modified CD8⁺ IEL. While the supplementation of leptin increased the proportion of CD8αα⁺ IEL (associated to a more intestinal phenotype), adiponectin enhanced that of CD8αβ⁺ (related to a peripheral phenotype). Furthermore, both adipokines enhanced the gene expression of TNF-α, MUC-2, and MUC-3, and decreased that of FcRn. In addition, the adipokine supplementations decreased the abundance of the Proteobacteria phylum and the presence of Blautia. Moreover, leptin-supplemented animals had lower relative abundance of Sutterella and a higher proportion of Clostridium genus, among others. However, supplementation with adiponectin resulted in lower abundance of the Roseburia genus and a higher proportion of the Enterococcus genus. In conclusion, the supplementation with leptin and adiponectin throughout the suckling period had an impact on both the IEL composition and the gut microbiota pattern, suggesting a modulatory role of these adipokines on the development of intestinal functionality.

The developmentally regulated fetal enterocyte gene, ZP4, mediates anti-inflammation by the symbiotic bacterial surface factor polysaccharide A on Bacteroides fragilis

Initial colonizing bacteria play a critical role in completing the development of the immune system in the gastrointestinal tract of infants. Yet, the interaction of colonizing bacterial organisms with the developing human intestine favors inflammation over immune homeostasis. This characteristic of bacterial-intestinal interaction partially contributes to the pathogenesis of necrotizing enterocolitis (NEC), a devastating premature infant intestinal inflammatory disease. However, paradoxically some unique pioneer bacteria (initial colonizing species) have been shown to have a beneficial effect on the homeostasis of the immature intestine and the prevention of inflammation. We have reported that one such pioneer bacterium, Bacteroides fragilis (B. fragilis), and its surface component polysaccharide A (PSA) inhibit IL-1β-induced inflammation in a human primary fetal small intestinal cell line (H4 cells). In this study, using transcription profiling of H4 cellular RNA after pretreatment with or without PSA before an inflammatory stimulation of IL-1β, we have begun to further determine the cellular mechanism for anti-inflammation. We show that a developmentally regulated gene, zona pellucida protein 4 (ZP4), is uniquely elevated after IL-1β stimulation and reduced with PSA exposure. ZP4 was known as a sperm receptor-mediating species-specific binding protein in the initial life of mammals. However, its intestinal epithelial function is unclear. We found that ZP4 is a developmentally regulated gene involved with immune function and regulated by both Toll-like receptor 2 and 4. Knockdown of ZP4-affected PSA inhibited IL-8 mRNA expression in response to IL-1β. This represents an initial study of ZP4 innate immune function in immature enterocytes. This study may lead to new opportunity for efficient treatment of NEC.NEW & NOTEWORTHY This study extends previous observations to define the cellular mechanisms of polysaccharide A-induced anti-inflammation in immature enterocytes using transcription profiling of enterocyte genes after preexposure to polysaccharide A before an inflammatory stimulus with IL-1β.

Factors affecting the composition of the gut microbiota, and its modulation

Gut microbiota have important functions in the body, and imbalances in the composition and diversity of those microbiota can cause several diseases. The host fosters favorable microbiota by releasing specific factors, such as microRNAs, and nonspecific factors, such as antimicrobial peptides, mucus and immunoglobulin A that encourage the growth of specific types of bacteria and inhibit the growth of others. Diet, antibiotics, and age can change gut microbiota, and many studies have shown the relationship between disorders of the microbiota and several diseases and reported some ways to modulate that balance. In this review, we highlight how the host shapes its gut microbiota via specific and nonspecific factors, how environmental and nutritional factors affect it, and how to modulate it using prebiotics, probiotics, and fecal microbiota transplantation.

Effect of Early Limited Formula on Breastfeeding Duration in the First Year of Life: A Randomized Clinical Trial

IMPORTANCE

Breastfeeding through 6 and 12 months are 2 goals of the Centers for Disease Control and Prevention Healthy People 2020 initiative, but the 6-month goal is met for only 52% of US infants and the 12-month goal for 30% of US infants.

OBJECTIVE

To determine whether structured, short-term formula supplementation for at-risk neonates affects the proportion still breastfeeding at 6 and 12 months.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial conducted at 2 US academic medical centers enrolled 164 exclusively breastfeeding mother-infant dyads of mothers who were not yet producing copious milk and infants who were 24 to 72 hours old with newborn weight loss at or above the 75th percentile for age. Participants were enrolled from January 2015 through September 2016.

INTERVENTIONS

Early Limited Formula (ELF), a structured formula supplementation protocol (10 mL formula fed after each breastfeeding until mothers produced copious milk), compared with control dyads, who continued exclusive breastfeeding and received a safety teaching intervention.

MAIN OUTCOMES AND MEASURES

The study's primary outcome was any breastfeeding at 6 months. Secondary outcomes included age at breastfeeding cessation and any breastfeeding at 12 months. All outcomes were assessed by maternal phone survey.

RESULTS

Eighty-two newborns were randomized to ELF and 82 to the control group. Mean (SD) maternal age was 31.4 (5.9) years, and 114 (69.5%) self-identified as non-Hispanic white; 20 (12.2%), Hispanic; 17 (10.4%), Asian; 5 (3.0%), non-Hispanic black; and 7 (4.3%), other. Compared with controls, mothers randomized to ELF were less likely to be married (n = 53 [64.6%] vs n = 66 [80.5%]; P = .03) and had shorter mean (SD) intended duration of breastfeeding (8.6 [3.4] vs 9.9 [4.4] months; P = .049). Median (interquartile range) duration of breastfeeding in the cohort was 9 (6-12) months. At 6 months, 47 (65%) infants randomized to ELF were breastfeeding, compared with 60 (77%) of the control infants (absolute difference, -12%; 95% CI, -26% to 3%; P = .12). At 12 months, 21 of the 71 ELF infants available for analysis (29.6%) were breastfeeding, compared with 37 of the available 77 (48.1%) control infants (risk difference, -18%; 95% CI, -34% to -3%). Marital status and intended breastfeeding duration were both associated with breastfeeding duration; models adjusting for these found a hazard ratio for time-to-event of breastfeeding cessation through 12 months of 0.74 (95% CI, 0.48-1.14) for ELF infants compared with infants in the control group.

CONCLUSIONS AND RELEVANCE

In this cohort with high breastfeeding prevalence, ELF was not associated with any improvement in breastfeeding duration. Future research should examine the effect of ELF in populations at higher risk of early cessation.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02313181.

Current understanding of the role of gut dysbiosis in type 1 diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disorder that results from destruction of the insulin-producing pancreatic β-cells. The disease mainly affects juveniles. Changes in the composition of the gut microbiota (dysbiosis) and changes in the properties of the gut barrier have been documented in T1D subjects. Because these factors affect immune system functions, they are likely to play a role in disease pathogenesis. However, their exact role is currently not fully understood and is under intensive investigation. In this article we discuss recent advancements depicting the role of intestinal dysbiosis on immunity and autoimmunity in T1D. We also discuss therapies aimed at maintaining a healthy gut barrier as prevention strategies for T1D.

Longitudinal investigation of the swine gut microbiome from birth to market reveals stage and growth performance associated bacteria

BACKGROUND

Despite recent advances in the understanding of the swine gut microbiome at different growth stages, a comprehensive longitudinal study of the lifetime (birth to market) dynamics of the swine gut microbiome is lacking.

RESULTS

To fill in this gap of knowledge, we repeatedly collected a total of 273 rectal swabs from 18 pigs during lactation (day (d) 0, 11, 20), nursery (d 27, 33, 41, 50, 61), growing (d 76, 90, 104, 116), and finishing (d 130, 146, 159, 174) stages. DNA was extracted and subjected to sequencing with an Illumina Miseq sequencer targeting the V4 region of the 16S rRNA gene. Sequences were analyzed with the Deblur algorithm in the QIIME2 package. A total of 19 phyla were detected in the lifetime pig gut microbiome with Firmicutes and Bacteroidetes being the most abundant. Alpha diversity including community richness (e.g., number of observed features) and diversity (e.g., Shannon index) showed an overall increasing trend. Distinct shifts in microbiome structure along different growth stages were observed. LEfSe analysis revealed 91 bacterial features that are stage-specific. To validate these discoveries, we performed fecal microbiota transplantation (FMT) by inoculating weanling pigs with mature fecal microbiota from a growing stage pig. Similar stage-specific patterns in microbiome diversity and structures were also observed in both the FMT pigs and their littermates. Although FMT remarkably increased growth performance, it did not change the overall swine gut microbiome. Only a few taxa including those associated with Streptococcus and Clostridiaceae were enriched in the FMT pigs. These data, together with several other lines of evidence, indicate potential roles these taxa play in promoting animal growth performance. Diet, especially crude fiber from corn, was a major factor shaping the swine gut microbiome. The priority effect, i.e., the order and timing of species arrival, was more evident in the solid feed stages.

CONCLUSIONS

The distinct stage-associated swine gut microbiome may be determined by the differences in diet and/or gut physiology at different growth stages. Our study provides insight into mechanisms governing gut microbiome succession and also underscores the importance of optimizing stage-specific probiotics aimed at improving animal health and production.

Characteristics of the gut microbiota colonization, inflammatory profile, and plasma metabolome in intrauterine growth restricted piglets during the first 12 hours after birth

Intrauterine growth restriction (IUGR) predisposes newborns to inflammatory and metabolic disturbance. Disequilibrium of gut microbiota in early life has been implicated in the incidence of inflammation and metabolic diseases in adulthood. This study aimed to investigate the difference in gut microbiota colonization, cytokines and plasma metabolome between IUGR and normal birth weight (NBW) piglets in early life. At birth, reduced (P < 0.05) body, jejunum, and ileum weights, as well as decreased (P < 0.05) small intestinal villi and increased (P < 0.05) ileal crypt depth were observed in IUGR piglets compared with their NBW counterparts. Imbalanced inflammatory and plasma metabolome profile was observed in IUGR piglets. Furthermore, altered metabolites were mainly involved in fatty acid metabolism and inflammatory response. At 12 h after birth and after suckling colostrum, reduced (P < 0.05) postnatal growth and the small intestinal maturation retardation (P < 0.05) continued in IUGR piglets in comparison with those in NBW littermates. Besides, the gut microbiota structure was significantly altered by IUGR. Importantly, the disruption of the inflammatory profile and metabolic status mainly involved the pro-inflammatory cytokines (IL-1β and IFN-γ) and amino acid metabolism. Moreover, spearman correlation analysis showed that the increased abundance of Escherichia-Shigella and decreased abundance of Clostridium_sensu_stricto_1 in IUGR piglets was closely associated with the alterations of slaughter weight, intestinal morphology, inflammatory cytokines, and plasma metabolites. Collectively, IUGR significantly impairs small intestine structure, modifies gut microbiota colonization, and disturbs inflammatory and metabolic profiles during the first 12 h after birth. The unbalanced gut microbiota mediated by IUGR contributes to the development of inflammation and metabolic diseases.

Neonatal iron distribution and infection susceptibility in full term, preterm and low birthweight babies in urban Gambia: study protocol for an observational study

Background: Neonatal infection is the third largest cause of death in children under five worldwide.  Nutritional immunity is the process by which the host innate immune system limits nutrient availability to invading organisms. Iron is an essential micronutrient for both microbial pathogens and their mammalian hosts. Changes in iron availability and distribution have significant effects on pathogen virulence and on the immune response to infection. Our previously published data shows that, during the first 24 hours of life, full-term neonates have reduced overall serum iron. Transferrin saturation decreases rapidly from 45% in cord blood to ~20% by six hours post-delivery. Methods: To study neonatal nutritional immunity and its role in neonatal susceptibility to infection, we will conduct an observational study on 300 full-term normal birth weight (FTB+NBW), 50 preterm normal birth weight (PTB+NBW), 50 preterm low birth weight (PTB+LBW) and 50 full-term low birth weight (FTB+LBW), vaginally-delivered neonates born at Kanifing General Hospital, The Gambia. We will characterize and quantify iron-related nutritional immunity during the early neonatal period and use ex vivo sentinel bacterial growth assays to assess how differences in serum iron affect bacterial growth. Blood samples will be collected from the umbilical cord (arterial and venous) and at serial time points from the neonates over the first week of life. Discussion: Currently, little is known about nutritional immunity in neonates. In this study, we will increase understanding of how nutritional immunity may protect neonates from infection during the first critical days of life by limiting the pathogenicity and virulence of neonatal sepsis causing organisms by reducing the availability of iron. Additionally, we will investigate the hypothesis that this protective mechanism may not be activated in preterm and low birth weight neonates, potentially putting these babies at an enhanced risk of neonatal infection. Trial registration: clinicaltrials.gov ( NCT03353051) 27/11/2017.

Gut Microbiota Disorder, Gut Epithelial and Blood-Brain Barrier Dysfunctions in Etiopathogenesis of Dementia: Molecular Mechanisms and Signaling Pathways

Emerging evidences indicate a critical role of the gut microbiota in etiopathogenesis of dementia, a debilitating multifactorial disorder characterized by progressive deterioration of cognition and behavior that interferes with the social and professional functions of the sufferer. Available data suggest that gut microbiota disorder that triggers development of dementia is characterized by substantial reduction in specific species belonging to the Firmicutes and Bacteroidetes phyla and presence of pathogenic species, predominantly, pro-inflammatory bacteria of the Proteobacteria phylum. These changes in gut microbiota microecology promote the production of toxic metabolites and pro-inflammatory cytokines, and reduction in beneficial substances such as short chain fatty acids and other anti-inflammatory factors, thereby, enhancing destruction of the gut epithelial barrier with concomitant activation of local and distant immune cells as well as dysregulation of enteric neurons and glia. This subsequently leads to blood-brain barrier dysfunctions that trigger neuroinflammatory reactions and predisposes to apoptotic neuronal and glial cell death, particularly in the hippocampus and cerebral cortex, which underlie the development of dementia. However, the molecular switches that control these processes in the histo-hematic barriers of the gut and brain are not exactly known. This review integrates very recent data on the molecular mechanisms that link gut microbiota disorder to gut epithelial and blood-brain barrier dysfunctions, underlying the development of dementia. The signaling pathways that link gut microbiota disorder with impairment in cognition and behavior are also discussed. The review also highlights potential therapeutic options for dementia.

Influence of own mother's milk and different proportions of formula on intestinal microbiota of very preterm newborns

Objective

To determine the differences in preterm infants’ stool microbiota considering the use of exclusive own mother’s milk and formula in different proportions in the first 28 days of life.

Methods

The study included newborns with GA ≤ 32 weeks divided in 5 group according the feeding regimen: 7 exclusive own mother’s milk, 8 exclusive preterm formula, 16 mixed feeding with >70% own mother’s milk, 16 mixed feeding with >70% preterm formula, and 15 mixed 50% own mother’s milk and preterm formula. Exclusion criteria: congenital infections, congenital malformations and newborns of drug addicted mothers. Stools were collected weekly during the first 28 days. Microbial DNA extraction, 16S rRNA amplification and sequencing were performed.

Results

All groups were similar in perinatal and neonatal data. There were significant differences in microbial community among treatments. Approximately 37% of the variation in distance between microbial communities was explained by use of exclusive own mother´s milk only compared to other diets. The diet composed by exclusive own mother´s milk allowed for greater microbial richness (average of 85 OTUs) while diets based on preferably formula, exclusive formula, preferably maternal milk, and mixed of formula and maternal milk presented an average of 9, 29, 23, and 25 OTUs respectively. The mean proportion of the genus Escherichia and Clostridium was always greater in those containing formula than in the those with maternal milk only.

Conclusions

Fecal microbiota in the neonatal period of preterm infants fed with exclusive own mother’s milk presented increased richness and differences in microbial composition from those fed with different proportions of formula.

Mycobiome Profiles in Breast Milk from Healthy Women Depend on Mode of Delivery, Geographic Location, and Interaction with Bacteria

Recent studies report the presence of fungal species in breast milk of healthy mothers, suggesting a potential role in infant mycobiome development. In the present work, we aimed to determine whether the healthy human breast milk mycobiota is influenced by geographical location and mode of delivery, as well as to investigate its interaction with bacterial profiles in the same samples. A total of 80 mature breast milk samples from 4 different countries were analyzed by Illumina sequencing of the internal transcribed spacer 1 (ITS1) region, joining the 18S and 5.8S regions of the fungal rRNA region. Basidiomycota and Ascomycota were found to be the dominant phyla, with Malassezia and Davidiella being the most prevalent genera across countries. A core formed by Malassezia, Davidiella, Sistotrema, and Penicillium was shared in the milk samples from the different origins, although specific shifts in mycobiome composition were associated with geographic location and delivery mode. The presence of fungi in the breast milk samples was further confirmed by culture and isolate characterization, and fungal loads were estimated by quantitative PCR (qPCR) targeting the fungal ITS1 region. Cooccurrence network analysis of bacteria and fungi showed complex interactions that were influenced by geographical location, mode of delivery, maternal age, and pregestational body mass index. The presence of a breast milk mycobiome was confirmed in all samples analyzed, regardless of the geographic origin.IMPORTANCE During recent years, human breast milk has been documented as a potential source of bacteria for the newborn. Recently, we have reported the presence of fungi in breast milk from healthy mothers. It is well known that environmental and perinatal factors can affect milk bacteria; however, the impact on milk fungi is still unknown. The current report describes fungal communities (mycobiota) in breast milk samples across different geographic locations and the influence of the mode of delivery. We also provide novel insights on bacterium-fungus interactions, taking into account environmental and perinatal factors. We identified a core of four genera shared across locations, consisting of Malassezia, Davidiella, Sistotrema, and Penicillium, which have been reported to be present in the infant gut. Our data confirm the presence of fungi in breast milk across continents and support the potential role of breast milk in the initial seeding of fungal species in the infant gut.

Interventions to prevent iron deficiency during the first 1000 days in low-income and middle-income countries: recent advances and challenges

PURPOSE OF REVIEW

Iron deficiency remains highly prevalent in women and young children in low-income and middle-income countries. To prevent the potentially life-long consequences of iron deficiency when occurring during early life, the WHO recommends iron supplementation of pregnant women and young children. However, increasing evidence of limited efficacy and risk of current iron intervention strategies are cause of concern. This review aims to highlight recent advances and challenges of established and novel intervention strategies for the prevention of iron deficiency during the first 1000 days in low-income and middle-income countries.

RECENT FINDINGS

Recent meta-analyses and trials challenged the WHO's current recommendation to provide iron-folic acid rather than multiple micronutrient supplements during routine antenatal care. Furthermore, several studies explored optimal windows for iron supplementation, such as prior to conception. Studies are demonstrating that infectious and noninfectious inflammation is compromising the efficacy of iron interventions in vulnerable groups. Therefore, strategies addressing iron deficiency should focus on targeting infection and inflammation while simultaneously providing additional iron. Furthermore, both iron deficiency and iron supplementation may promote an unfavourable gut microbiota. Recent trials in infants indicate that the provision of a prebiotic together with iron may alleviate the adverse effects of iron on the gut microbiome and gut inflammation, and may even enhance iron absorption.

SUMMARY

Recent studies highlight the need for and potential of novel intervention strategies that increase the efficacy and limit the potential harm of universal iron supplementation.

Type E Botulinum Neurotoxin-Producing Clostridium butyricum Strains Are Aerotolerant during Vegetative Growth

Botulinum neurotoxins, the causative agents of the potentially fatal disease of botulism, are produced by certain Clostridium strains during vegetative growth, usually in anaerobic environments. Our findings indicate that, contrary to current understanding, the growth of neurotoxigenic C. butyricum strains and botulinum neurotoxin type E production can continue upon transfer from anaerobic to aerated conditions and that adaptation of strains to oxygenated environments requires global changes in proteomic and metabolic profiles. We hypothesize that aerotolerance might constitute an unappreciated factor conferring physiological advantages on some botulinum toxin-producing clostridial strains, allowing them to adapt to otherwise restrictive environments.

Clostridium butyricum, the type species of the genus Clostridium, is considered an obligate anaerobe, yet it has been shown to grow in the presence of oxygen. C. butyricum strains atypically producing the botulinum neurotoxin type E are the leading cause of type E human botulism in Italy. Here, we show that type E botulinum neurotoxin-producing C. butyricum strains growing exponentially were able to keep growing and producing toxin in vitro upon exposure to air, although less efficiently than under ideal oxygen-depleted conditions. Bacterial growth in air was maintained when the initial cell density was higher than 10³ cells/ml. No spores were detected in the cultures aerated for 5 h. To understand the biological mechanisms allowing the adaptation of vegetative cells of C. butyricum type E to oxygen, we compared the proteome and metabolome profiles of the clostridial cultures grown for 5 h under either aerated or anaerobic conditions. The results indicated that bacterial cells responded to oxygen stress by slowing growth and modulating the expression of proteins involved in carbohydrate uptake and metabolism, redox homeostasis, DNA damage response, and bacterial motility. Moreover, the ratio of acetate to butyrate was significantly higher under aeration. This study demonstrates for the first time that a botulinum neurotoxin-producing Clostridium can withstand oxygen during vegetative growth.

IMPORTANCE Botulinum neurotoxins, the causative agents of the potentially fatal disease of botulism, are produced by certain Clostridium strains during vegetative growth, usually in anaerobic environments. Our findings indicate that, contrary to current understanding, the growth of neurotoxigenic C. butyricum strains and botulinum neurotoxin type E production can continue upon transfer from anaerobic to aerated conditions and that adaptation of strains to oxygenated environments requires global changes in proteomic and metabolic profiles. We hypothesize that aerotolerance might constitute an unappreciated factor conferring physiological advantages on some botulinum toxin-producing clostridial strains, allowing them to adapt to otherwise restrictive environments.

Characterization of the Early Life Microbiota Development and Predominant Lactobacillus Species at Distinct Gut Segments of Low- and Normal-Birth-Weight Piglets

Microbial exposure during early life plays a pivotal role in modulating the health and intestinal development of the host. Our recent study showed that the low-birth-weight (LBW) piglets harbored a different fecal microbiota compared to normal-birth-weight (NBW) piglets during early life with a lower abundance of the genus Lactobacillus. Considering the spatial variations in gut microbiota at distinct gut locations, this study was designed to further investigate the differences in the microbiota composition and predominant Lactobacillus species in the ileum and colon between LBW and NBW piglets during early life, including day 7 (D7), day 21 (D21, before weaning), and day 35 (D35, 2 weeks after weaning). Compared with the normal group, LBW piglets harbored a significantly lower proportion of short-chain fatty acids producing microbes, such as Ruminococcaceae and Prevotellaceae in the ileum on D7, Alistipes and Lachnospiraceae in the colon on D7, Blautia in the colon on D21, and Ruminiclostridium 9 in the colon on D35. The relative abundance of the phylum Bacteroidetes was also declined in both ileum and colon of LBW piglets on D7. Meanwhile, the levels of total SCFAs on D7, D21, and D35, acetate and valerate on D7 and D21, propionate on D21, and lactate on D21 and D35, were also declined in the colon of LBW piglets. Moreover, functional alterations in the gut microbiota of LBW piglets were characterized by differentially abundant microbial genes involved in multiple pathways such as amino acid metabolism, energy metabolism, replication and repair, and metabolism of cofactors and vitamins in the colon. Additionally, lower numbers of L. salivarius on D7 and L. amylovorus on D21 resided in the colon of LBW piglets compared to those in the normal ones. Collectively, LBW piglets have altered bacterial communities, microbial metabolism and gene functions in the ileum and colon during early life, especially the colonic community. This work will help to develop novel ideas in identifying the reliable biomarkers affecting the gut microbiota development in LBW piglets during early life and facilitate the development of new nutritional interventions.

Toward rational selection criteria for selection of probiotics in pigs

An accurate understanding of properties of probiotics is a prerequisite for selecting probiotic organisms for use in swine production. This review aims to review selection criteria for probiotic organism in swine. The systematically investigated ecological history rather than the source of isolates should be regarded as the natural origin of probiotic strains, which helps to correct the inconsistencies arising from incorrect identification of the source. Moreover, in vivo studies are suggested as follow-up assessment to validate the characteristics of probiotic predicted by in vitro experiments. In addition, the intended probiotic effect depends on the age of the animal and disease prevention in young animals may require different probiotic strains when compared to growth promotion in older animals. With adequate selection criteria, the inclusion of probiotic in feed supplementation is a promising way to exert positive effects on sows, newborns, weanling animals and grower-finisher pigs. Both host-adapted probiotics and nomadic probiotics can be applied for pathogen inhibition but host adapted organisms appear to have a different mode of action. Host-adapted probiotic strains are likely to be associated with exclusive colonization while the nomadic or environmental strain exert better immune stimulating functions. Strains with potent enzymatic activity are fitter for grower pigs favoring feed digestion and enhancing growth performance.

The Preterm Gut Microbiota: An Inconspicuous Challenge in Nutritional Neonatal Care

The nutritional requirements of preterm infants are unique and challenging to meet in neonatal care, yet crucial for their growth, development and health. Normally, the gut microbiota has distinct metabolic capacities, making their role in metabolism of dietary components indispensable. In preterm infants, variation in microbiota composition is introduced while facing a unique set of environmental conditions. However, the effect of such variation on the microbiota's metabolic capacity and on the preterm infant's growth and development remains unresolved. In this review, we will provide a holistic overview on the development of the preterm gut microbiota and the unique environmental conditions contributing to this, in addition to maturation of the gastrointestinal tract and immune system in preterm infants. The role of prematurity, as well as the role of human milk, in the developmental processes is emphasized. Current research stresses the early life gut microbiota as cornerstone for simultaneous development of the gastrointestinal tract and immune system. Besides that, literature provides clues that prematurity affects growth and development. As such, this review is concluded with our hypothesis that prematurity of the gut microbiota may be an inconspicuous clinical challenge in achieving optimal feeding besides traditional challenges, such as preterm breast milk composition, high nutritional requirements and immaturity of the gastrointestinal tract and immune system. A better understanding of the metabolic capacity of the gut microbiota and its impact on gut and immune maturation in preterm infants could complement current feeding regimens in future neonatal care and thereby facilitate growth, development and health in preterm infants.

Probiotics to prevent infantile colic

BACKGROUND

Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. Infantile colic affects a large number of infants and their families worldwide. Its symptoms are broad and general, and while not indicative of disease, may represent a serious underlying condition in a small percentage of infants who may need a medical assessment. Probiotics are live microorganisms that alter the microflora of the host and provide beneficial health effects. The most common probiotics used are of Lactobacillus, Bifidobacterium and Streptococcus. There is growing evidence to suggest that intestinal flora in colicky infants differ from those in healthy infants, and it is suggested that probiotics can redress this balance and provide a healthier intestinal microbiota landscape. The low cost and easy availability of probiotics makes them a potential prophylactic solution to reduce the incidence and prevalence of infantile colic.

OBJECTIVES

To evaluate the efficacy and safety of prophylactic probiotics in preventing or reducing severity of infantile colic.

SEARCH METHODS

In January 2018 we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, 10 other databases and two trials registers. In addition, we handsearched the abstracts of relevant meetings, searched reference lists, ran citation searches of included studies, and contacted authors and experts in the field, including the manufacturers of probiotics, to identify unpublished trials.

SELECTION CRITERIA

Randomised control trials (RCTs) of newborn infants less than one month of age without the diagnosis of infantile colic at recruitment. We included any probiotic, alone or in combination with a prebiotic (also known as synbiotics), versus no intervention, another intervention(s) or placebo, where the focus of the study was the effect of the intervention on infantile colic.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures of Cochrane.

MAIN RESULTS

Our search yielded 3284 records, and of these, we selected 21 reports for full-text review. Six studies with 1886 participants met our inclusion criteria, comparing probiotics with placebo. Two studies examined Lactobacillus reuteri DSM, two examined multi-strain probiotics, one examined Lactobacillus rhamnosus, and one examined Lactobacillus paracasei and Bifidobacterium animalis. Two studies began probiotics during pregnancy and continued administering them to the baby after birth.We considered the risk of bias for randomisation as low for all six trials; for allocation concealment as low in two studies and unclear in four others. All studies were blinded, and at low risk of attrition and reporting bias.A random-effects meta-analysis of three studies (1148 participants) found no difference between the groups in relation to occurrence of new cases of colic: risk ratio (RR) 0.46, 95% confidence interval (CI) 0.18 to 1.19; low-certainty evidence; I² = 72%.A random-effects meta-analysis of all six studies (1851 participants) found no difference between the groups in relation to serious adverse effects (RR 1.02, 95% CI 0.14 to 7.21; low-certainty evidence; I² not calculable (only four serious events for one comparison, two in each group: meconium plug obstruction, patent ductus arteriosus and neonatal hepatitis).A random-effects meta-analysis of three studies (707 participants) found a mean difference (MD) of -32.57 minutes per day (95% CI -55.60 to -9.54; low-certainty evidence; I² = 93%) in crying time at study end in favour of probiotics.A subgroup analysis of the most studied agent, Lactobacillus reuteri, showed a reduction of 44.26 minutes in daily crying with a random-effects model (95% CI -66.6 to -21.9; I² = 92%), in favour of probiotics.

AUTHORS' CONCLUSIONS

There is no clear evidence that probiotics are more effective than placebo at preventing infantile colic; however, daily crying time appeared to reduce with probiotic use compared to placebo. There were no clear differences in adverse effects.We are limited in our ability to draw conclusions by the certainty of the evidence, which we assessed as being low across all three outcomes, meaning that we are not confident that these results would not change with the addition of further research.

Shaping the Infant Microbiome With Non-digestible Carbohydrates

Natural polysaccharides with health benefits are characterized by a large structural diversity and differ in building blocks, linkages, and lengths. They contribute to human health by functioning as anti-adhesives preventing pathogen adhesion, stimulate immune maturation and gut barrier function, and serve as fermentable substrates for gut bacteria. Examples of such beneficial carbohydrates include the human milk oligosaccharides (HMOs). Also, specific non-digestible carbohydrates (NDCs), such as galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS) are being produced with this purpose in mind, and are currently added to infant formula to stimulate the healthy development of the newborn. They mimic some functions of HMO, but not all. Therefore, many research efforts focus on identification and production of novel types of NDCs. In this review, we give an overview of the few NDCs currently available [GOS, FOS, polydextrose (PDX)], and outline the potential of alternative oligosaccharides, such as pectins, (arabino)xylo-oligosaccharides, and microbial exopolysaccharides (EPS). Moreover, state-of-the-art techniques to generate novel types of dietary glycans, including sialylated GOS (Sia-GOS) and galactosylated chitin, are presented as a way to obtain novel prebiotic NDCs that help shaping the infant microbiome.

Establishment of an ideal gut microbiota to boost healthy growth of neonates

For decades, supporting the optimal growth of low birth weight (LBW) infants has been considered one of the most important paediatric challenges, despite advances in neonatal intensive care technology and nutrition interventions. Since gut microbiota affects such diverse phenotypes in adults, the difference in gut microbiota composition between normal infants and LBW infants raises the possibility of gut microbiota playing an important role in different growth rates of neonates. Based on the concept that probiotics are generally beneficial to the health, numerous studies have been made on probiotics as a supplement to the diet of the LBW infants. However, clinical results on the effects of probiotics on LBW infant growth are either inconsistent or contradictory with each other, and thus the contribution of gut microbiota in neonatal growth has remained inconclusive. In this review, recent researches on neonatal gut microbiota are discussed to develop a new strategy for targeting gut microbiota as a solution to growth retardation in LBW infants. We also discuss how to establish the ideal gut microbiota to support optimal growth of LBW infants.

Gut microbiota and pediatric obesity/non-alcoholic fatty liver disease

Huge amount microorganisms resides in human intestine, and many contribute to the maturation and homeostasis of immune system. The diversity of gut ecology are affected by the gestational age, delivery type, feeding sources, and antibiotics use in neonates. Recent studies pointed out that disturbance of gut microbiota, so called dysbiosis, could result in several pediatric diseases including obesity, non-alcoholic fatty liver disease (NAFLD), metabolic syndromes, allergic diseases, and inflammatory bowel diseases. However, there are no single species can be proven to play a key factor in pediatric obesity and NAFLD at present. Various probiotics may confer benefit to these gut microbiota-related pediatric diseases. The clinical application is still limited. This review article aimed to elucidate evidently the relationship between gut microbiota and pediatric obesity/NAFLD and to discuss the potential probiotics use in pediatric obesity and NAFLD.

An intensive milk replacer feeding program benefits immune response and intestinal microbiota of lambs during weaning

Background

Pre-weaning milk replacer (MR) feeding program is a key factor affecting the health and welfare of lambs during their weaning. Weaning stress is well known as an inducement that negatively impacts the immune system of young ruminants, whose physiological and immune state is closely linked to the community of microbiota in their intestines. This study had two objectives: 1) To evaluate the innate immune response to weaning stress at both the physiological and molecular level; 2) To investigate changes to the jejunal chyme and mucosal adhesive microbiota between the control and high plane of MR groups.

Results

In this experiment, the plasma concentrations of cortisol, norepinephrine (NE) and tumor necrosis factor-α (TNFα) were higher in the C than the H group (P < 0.05), as was the expression of pro-inflammatory cytokines such as TNFα and CXCL8 (P < 0.05) in plasma. In jejunal tissue, the expression of TLR4 and TNFα were also higher in the C group (P < 0.01); histopathology showed the H group had lower lymphocyte infiltration. In the C group, however, major pathological changes were associated with extensive infiltration of lymphocytes, eosinophils, and neutrophils. Principal component analysis indicated the lamb immune response was influenced by weaning stress and modulated by the MR treatments. 16S-rRNA sequencing was used to evaluate jejunal mucosa and chyme bacterial diversity and composition. The C group’s chyme had a greater alpha index (ACE: P = 0.095; Chao1: P = 0.085) than H group. In jejunal mucosa, the relative abundance of Plesiomonas was 4-fold higher (P = 0.017) in the C than the H group.

Conclusions

This study’s results revealed that weaning stress induced alterations to the lambs’ immune system that lasted beyond the 21 d measured, and that a long-term inflammatory response effect was evidenced by changes in their hematological and expressed pro-inflammatory cytokines. Pre-weaning with a differing MR allowance resulted in complicated biological responses and compositional changes to the lambs’ jejunal microbiota. Clearly, an intensive MR feeding program induced a milder immunity response and lower relative abundance of pathogenic bacteria when compared with the traditional feeding program.

Gut microbiota development in mice is affected by hydrogen peroxide produced from amino acid metabolism during lactation

The development of gut microbiota during infancy is an important event that affects the health status of the host; however, the mechanism governing it is not fully understood. l-Amino acid oxidase 1 (LAO1) is a flavoprotein that catalyzes the oxidative deamination of particular l-amino acids and converts them into keto acids, ammonia, and H₂O₂. Our previous study showed that LAO1 is present in mouse milk and exerts protection against bacteria by its production of H₂O₂. The data led us to consider whether LAO1, H₂O₂, or both could impact infant gut microbiota development via mother's milk consumption in mice. Different gut microbiota profiles were observed in the wild-type (WT) and LAO1-knockout mouse pups. The WT pups' microbiota was relatively simple and composed of only a few dominant bacteria, such as Lactobacillus, whereas the lactating knockout pups had high microbiota diversity. Cross-fostering experiments indicated that WT milk (containing LAO1) has the ability to suppress the diversity of microbiota in pups. We observed that the stomach content of pups fed WT milk had LAO1 proteins and the ability to produce H₂O₂. Moreover, culture experiments showed that Lactobacillus was abundant in the feces of pups fed WT milk and that Lactobacillus was more resistant to H₂O₂ than Bifidobacterium and Escherichia. Human breast milk produces very little H₂O₂, which could be the reason for Lactobacillus not being dominant in the feces of breast-fed human infants. In mouse mother's milk, H₂O₂ is generated from the process of free amino acid metabolism, and H₂O₂ may be a key player in regulating the initial acquisition and development of gut microbiota, especially growth of Lactobacillus, during infancy.-Shigeno, Y., Zhang, H., Banno, T., Usuda, K., Nochi, T., Inoue, R., Watanabe, G., Jin, W., Benno, Y., Nagaoka, K. Gut microbiota development in mice is affected by hydrogen peroxide produced from amino acid metabolism during lactation.

Initial microbial community of the neonatal stomach immediately after birth

The purpose of this prospective cross-sectional cohort pilot study is to explore the initial microbial community of gastric aspirate fluid as collected immediately after birth and its relationships with mode of delivery and preterm birth. Twenty-nine gastric aspirate samples collected immediately after birth from infants born between 24-40 weeks gestation were analyzed for microbial composition. Total microbial content was low in many samples, with a substantial number sharing taxonomic composition with negative controls. qPCR targeting the 16S rRNA gene showed that infants delivered vaginally had a higher microbial load than infants delivered by C-section. Some pre-term samples showed high relative abundance of genus Ureaplasma, consistent with previous literature that has implicated infections with this taxon as a potential cause of pre-term birth. Vaginally born term infant samples, by contrast, had significantly higher levels of genus Lactobacillus with Lactobacillus crispatus the most dominant species. Microbial evaluation showed that vaginally born term infant gastric aspirate samples had higher levels of lactobacilli than pre-terms. Samples from many infants had low microbial load near the edge of the detection limit.

A novel nano-iron supplement to safely combat iron deficiency and anaemia in young children: The IHAT-GUT double-blind, randomised, placebo-controlled trial protocol

Background: Iron deficiency and its associated anaemia (IDA) are the leading forms of micronutrient malnutrition worldwide. Here we describe the rationale and design of the first clinical trial evaluating the efficacy and safety of an innovative nano iron supplement, iron hydroxide adipate tartrate (IHAT), for the treatment of IDA in young children (IHAT-GUT trial). Oral iron is often ineffective due to poor absorption and/or gastrointestinal adverse effects. IHAT is novel since it is effectively absorbed whilst remaining nanoparticulate in the gut, therefore should enable supplementation with fewer symptoms. Methods: IHAT-GUT is a three-arm, double-blind, randomised, placebo-controlled phase II trial conducted in Gambian children 6-35 months of age. The intervention consists of a 12-week supplementation with either IHAT, ferrous sulphate (both at doses bioequivalent to 12.5 mg Fe/day) or placebo. The trial aims to include 705 children with IDA who will be randomly assigned (1:1:1) to each arm. The primary objectives are to test non-inferiority of IHAT in relation to ferrous sulphate at treating IDA, and to test superiority of IHAT in relation to ferrous sulphate and non-inferiority in relation to placebo in terms of diarrhoea incidence and prevalence. Secondary objectives are mechanistic assessments, to test whether IHAT reduces the burden of enteric pathogens, morbidity, and intestinal inflammation, and that it does not cause detrimental changes to the gut microbiome, particularly in relation to Lactobacillaceae, Bifidobacteriaceae and Enterobacteriaceae. Discussion: This trial will test the hypothesis that supplementation with IHAT eliminates iron deficiency and improves haemoglobin levels without inducing gastrointestinal adverse effects. If shown to be the case, this would open the possibility for further testing and use of IHAT as a novel iron source for micronutrient intervention strategies in resource-poor countries, with the ultimate aim to help reduce the IDA global burden. Registration: This trial is registered at clinicaltrials.gov ( NCT02941081).

A novel nano-iron supplement to safely combat iron deficiency and anaemia in young children: The IHAT-GUT double-blind, randomised, placebo-controlled trial protocol

Background: Iron deficiency and its associated anaemia (IDA) are the leading forms of micronutrient malnutrition worldwide. Here we describe the rationale and design of the first clinical trial evaluating the efficacy and safety of an innovative nano iron supplement, iron hydroxide adipate tartrate (IHAT), for the treatment of IDA in young children (IHAT-GUT trial). Oral iron is often ineffective due to poor absorption and/or gastrointestinal adverse effects. IHAT is novel since it is effectively absorbed whilst remaining nanoparticulate in the gut, therefore should enable supplementation with fewer symptoms. Methods: IHAT-GUT is a three-arm, double-blind, randomised, placebo-controlled phase II trial conducted in Gambian children 6-35 months of age. The intervention consists of a 12-week supplementation with either IHAT, ferrous sulphate (both at doses bioequivalent to 12.5 mg _Fe/day) or placebo. The trial aims to include 705 children with IDA who will be randomly assigned (1:1:1) to each arm. The primary objectives are to test non-inferiority of IHAT in relation to ferrous sulphate at treating IDA, and to test superiority of IHAT in relation to ferrous sulphate and non-inferiority in relation to placebo in terms of diarrhoea incidence and prevalence. Secondary objectives are mechanistic assessments, to test whether IHAT reduces the burden of enteric pathogens, morbidity, and intestinal inflammation, and that it does not cause detrimental changes to the gut microbiome, particularly in relation to Lactobacillaceae, Bifidobacteriaceae and Enterobacteriaceae. Discussion: This trial will test the hypothesis that supplementation with IHAT eliminates iron deficiency and improves haemoglobin levels without inducing gastrointestinal adverse effects. If shown to be the case, this would open the possibility for further testing and use of IHAT as a novel iron source for micronutrient intervention strategies in resource-poor countries, with the ultimate aim to help reduce the IDA global burden. Registration: This trial is registered at clinicaltrials.gov ( NCT02941081).

Direct-fed microbial supplementation influences the bacteria community composition of the gastrointestinal tract of pre- and post-weaned calves

This study investigated the effect of supplementing the diet of calves with two direct fed microbials (DFMs) (Saccharomyces cerevisiae boulardii CNCM I-1079 (SCB) and Lactobacillus acidophilus BT1386 (LA)), and an antibiotic growth promoter (ATB). Thirty-two dairy calves were fed a control diet (CTL) supplemented with SCB or LA or ATB for 96 days. On day 33 (pre-weaning, n = 16) and day 96 (post-weaning, n = 16), digesta from the rumen, ileum, and colon, and mucosa from the ileum and colon were collected. The bacterial diversity and composition of the gastrointestinal tract (GIT) of pre- and post-weaned calves were characterized by sequencing the V3-V4 region of the bacterial 16S rRNA gene. The DFMs had significant impact on bacteria community structure with most changes associated with treatment occurring in the pre-weaning period and mostly in the ileum but less impact on bacteria diversity. Both SCB and LA significantly reduced the potential pathogenic bacteria genera, Streptococcus and Tyzzerella_4 (FDR ≤ 8.49E-06) and increased the beneficial bacteria, Fibrobacter (FDR ≤ 5.55E-04) compared to control. Other potential beneficial bacteria, including Rumminococcaceae UCG 005, Roseburia and Olsenella, were only increased (FDR ≤ 1.30E-02) by SCB treatment compared to control. Furthermore, the pathogenic bacterium, Peptoclostridium, was reduced (FDR = 1.58E-02) by SCB only while LA reduced (FDR = 1.74E-05) Ruminococcus_2. Functional prediction analysis suggested that both DFMs impacted (p < 0.05) pathways such as cell cycle, bile secretion, proteasome, cAMP signaling pathway, thyroid hormone synthesis pathway and dopaminergic synapse pathway. Compared to the DFMs, ATB had similar impact on bacterial diversity in all GIT sites but greater impact on the bacterial composition of the ileum. Overall, this study provides an insight on the bacteria genera impacted by DFMs and the potential mechanisms by which DFMs affect the GIT microbiota and may therefore facilitate development of DFMs as alternatives to ATB use in dairy calf management.

Exposure to Yeast Shapes the Intestinal Bacterial Community Assembly in Zebrafish Larvae

Establishment of the early-life gut microbiota has a large influence on host development and succession of microbial composition in later life stages. The effect of commensal yeasts - which are known to create a conducive environment for beneficial bacteria - on the structure and diversity of fish gut microbiota still remains unexplored. The present study examined the intestinal bacterial community of zebrafish (Danio rerio) larvae exposed to two fish-derived yeasts by sequencing the V4 hypervariable region of bacterial 16S rRNA. The first stage of the experiment (until 7 days post-fertilization) was performed in cell culture flasks under sterile and conventional conditions for germ-free (GF) and conventionally raised (CR) larvae, respectively. The second phase was carried out under standard rearing conditions, for both groups. Exposure of GF and CR zebrafish larvae to one of the yeast species Debaryomyces or Pseudozyma affected the bacterial composition. Exposure to Debaryomyces resulted in a significantly higher abundance of core bacteria. The difference was mainly due to shifts in relative abundance of taxa belonging to the phylum Proteobacteria. In Debaryomyces-exposed CR larvae, the significantly enriched taxa included beneficial bacteria such as Pediococcus and Lactococcus (Firmicutes). Furthermore, most diversity indices of bacterial communities in yeast-exposed CR zebrafish were significantly altered compared to the control group. Such alterations were not evident in GF zebrafish. The water bacterial community was distinct from the intestinal microbiota of zebrafish larvae. Our findings indicate that early exposure to commensal yeast could cause differential bacterial assemblage, including the establishment of potentially beneficial bacteria.

Study of the In Vitro Antagonistic Activity of Various Single-Strain and Multi-Strain Probiotics against Escherichia coli

Escherichia coli is an important commensal of our gut, however, many pathogenic strains exist, causing various severe infections in the gut or beyond. Due to several antibiotic resistance patterns of E. coli, research of alternative treatments or adjuvant therapy is important. One of these is the use of probiotics as antagonistic agents against E. coli. Most published studies investigate only one strain of E. coli and single-strain probiotics. The objectives of this study were to evaluate the antagonistic activity of selected single-strain and multi-strain probiotic supplements against selected clinical E. coli pathotypes using the in vitro agar spot test and the co-culturing method. Molecular methods were used to determine the presence of the genus lactobacilli and bifidobacteria as well as certain selected strains in the probiotic supplements. The agar-spot test showed that the multi-strain probiotics were more effective than the single-strain probiotics. On the other hand, the co-culturing method showed the opposite result, indicating that results are importantly influenced by the chosen method. The most effective single-strain probiotics against E. coli strains were Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus reuteri DSM 17938. The most effective multi-strain probiotics contained lactobacilli, bifidobacteria and enterococci strains, thus proving that most effective probiotics against E. coli strains are the lactic acid bacteria and bifidobacteria. The overall results from both in vitro tests reveal that all selected probiotics exhibited an antagonistic activity against all E. coli strains. From a public health perspective probiotics have thus proved to be successful in inhibiting the growth of E. coli and could therefore be used as adjuvant therapy or alternative therapy in E. coli infections.

Gut Microbiota and Mucosal Immunity in the Neonate

Gut microbiota colonization is a complex, dynamic, and step-wise process that is in constant development during the first years of life. This microbial settlement occurs in parallel with the maturation of the immune system, and alterations during this period, due to environmental and host factors, are considered to be potential determinants of health-outcomes later in life. Given that host–microbe interactions are mediated by the immune system response, it is important to understand the close relationship between immunity and the microbiota during birth, lactation, and early infancy. This work summarizes the evidence to date on early gut microbiota colonization, and how it influences the maturation of the infant immune system and health during the first 1000 days of life. This review will also address the influence of perinatal antibiotic intake and the importance of delivery mode and breastfeeding for an appropriate development of gut immunity.