The importance of appropriate initial bacterial colonization of the intestine in newborn, child, and adult health

Influence of fatty acid distribution on lipid metabolism and cognitive development in first-weaned mice

There are significant structural differences between breast milk fat and the fat found in existing infant formulas, and these differences may partly explain the observed variations in growth and development between breastfed and formula-fed infants. This study used mice compared three groups: a control group (mixed vegetable oil), an OPO group (vegetable oil added with OPO), and a human milk fat substitute (HMFS) group formulated to match the fatty acid composition of breast milk. Compared to the control group and OPO group, HMFS-fed mice exhibited reduced body fat content and improved cognitive abilities. Lipidomics studies revealed that these differences in HMFS mice were associated with downregulation of hepatic glycerolipids and upregulation of glycerophospholipids and sphingolipids, facilitating the delivery of long-chain polyunsaturated fatty acids to the brain. Molecular investigations confirmed that HMFS reduces body fat accumulation by inhibiting endogenous fatty acid synthesis and promoting fatty acid β-oxidation, while changes in hepatic lipid profiles result from lipid molecule synthesis and interconversion. Metataxonomic studies demonstrated that HMFS reshaped the gut microbiota, including upregulating Akkermansia and downregulating Desulfovibrio and the Firmicutes/Bacteroidetes ratio, with strong correlations observed between the change of gut microbiota and responded lipids in liver. Overall, the breast milk's unique fatty acid distribution promotes organismal growth by modulating hepatic lipid metabolism, systemic lipid circulation, and gut microbiota. These findings underscore the nutritional benefits of breast milk fat structure and provide insights for the development of next-generation infant formulas.

Gastrointestinal (GI)-lung-brain axis

The GI tract-lung-brain axis refers to the communication network linking the gastrointestinal tract, central nervous system, and respiratory system. This axis is particularly significant in preterm neonates because their immune and nervous systems are undergoing rapid development and thus are susceptible to various conditions influenced by GI tract and lung microbiota that are key mediators in this axis. This communication network is connected via neural, hormonal, and immunological regulatory pathways, all of which are pivotal in disease pathogenesis and health. Here we provide a brief introduction to this axis along with interactive mechanisms and perturbations that can affect this system and the roles they play in health and disease.

Self-Nourishing and Armored Probiotics via Egg-Inspired Encapsulation

The gut microbiota plays an essential role in regulating overall physiology, including metabolism and neurological and immune functions. Therefore, their dysregulation is closely associated with metabolic disorders, such as obesity and diabetes, as well as other pathological conditions, including inflammatory bowel diseases, cancer, and neurological disorders. Probiotics are commonly used to maintain a healthy gut microbiome, but their oral delivery is inefficient mainly due to their poor stability in the harsh gastrointestinal (GI) environment. This work presents an innovative encapsulation strategy, inspired by the natural structure of an egg, for the effective oral delivery of probiotics, termed PIE (Probiotics-In-Egg). The PIE technology is based upon encapsulating probiotics with phosvitin and ovalbumin derived from egg yolk and egg white, respectively. PIE exhibits significantly enhanced survival and proliferation in a simulated GI tract, as well as the ability to neutralize harmful reactive oxygen species (ROS) and sustain in nutrient-depleted conditions. Moreover, when administered orally in mouse models, PIE demonstrates excellent bioavailability and enhanced colonization in the GI tract. This egg-inspired encapsulation technology has great potential as a practical and effective platform for oral delivery of probiotics, which can significantly help maintain a healthy gut microbiome.

Synergism between TLR4 and B. infantis in the development of the premature intestine

BACKGROUND

Intestinal microbiota has a role in early life maturation including maturation of intestinal immune function. However, the interaction of the TLR4 with colonizing bacteria in intestinal development is incompletely understood.

METHODS

An established human immature small intestinal cell line, human fetal intestinal organoids, and wild-type (WT) and TLR4 gene knockout (TLR4 -/-) neonatal mice were used to test the synergism between the innate immune receptor TLR4 and postbiotics from Bifidobacteria longum subsp. infantis (B. infantis) in development of the premature intestine.

RESULTS

TLR4-mediated postbiotics induced immature enterocyte proliferation and filamentous actin (F-actin) maturation both at the mRNA and protein levels. Proliferation of mRNA levels increased in wild-type mice but not in TLR4 -/- mice fed by postbiotics, both in the ileum and colon. Postbiotics can also change tight junction distribution in WT neonatal colon but not in TLR4 -/- mice.

CONCLUSIONS

Our data suggest a novel regulation of intestinal development by a synergistic role of the innate immune receptor TLR4 and early life colonizing bacteria, such as B. infantis. This study should provide new insights into the mechanisms of intestinal maturation as well as opportunities to target novel approaches to NEC prevention and treatment.

IMPACT

The innate immune system and postbiotics affect immature intestinal development. The innate immune receptor TLR4 prevention of NEC. Mechanism of prevention of NEC. This is the first time this has been demonstrated in human fetal intestine. In vitro process for future clinical studies for prevention of NEC.

The Role of the Gut Microbiota in Health, Diet, and Disease with a Focus on Obesity

The gut microbiota has been increasingly recognised as a critical determinant of human health, influencing a wide range of physiological processes. A healthy gut microbiota is essential for maintaining metabolic, immune, and gastrointestinal homeostasis, contributing to overall well-being. Alterations in its composition and functionality, often referred to as microbial dysbiosis, are strongly associated with the development of gut-related and systemic diseases. The gut microbiota synthesises several components and interacts with epithelial cell receptors, influencing processes that extend beyond nutritional status to the pathogenesis of diseases such as obesity, which extend beyond their known contribution to nutritional status. Therefore, this state-of-the-art review synthesises findings from recent studies on the composition, functions, and influencing factors of the gut microbiota, with a focus on its role in obesity. A systematic search of peer-reviewed literature was conducted to ensure comprehensive coverage, while expert insights are incorporated to discuss emerging research directions and future perspectives in the field.

Effect of folpet on hypoglycaemia, intestinal microbiota, and drug resistance genes in mice

BACKGROUND

Folpet is a nonspecific sulfonamide fungicide widely used to protect crops from mildew. However, the in vivo effects of folpet on glucose metabolism homeostasis, gut microbiota, and abundance of drug resistance genes remain unknown. The purpose of this study was to assess the effects of the pesticide, folpet, on glucose metabolism homeostasis, and folpet-induced changes in the intestinal microbiota and resistance genes in mice.

METHODS

Mice were orally administered folpet at 0, 1, 10, and 100 mg/kg body weight/day for 5 weeks. Blood sugar levels in mice were measured after 5 weeks of folpet administration. Metagenomic sequencing and drug resistance gene analyses were performed to explore changes in the abundance of gut microbiota members and drug resistance genes in mice after folpet administration. Correlation analysis was performed using metabolomics to explore the relationship between intestinal microbiota, drug resistance genes, and glucose metabolism.

RESULTS

Mice in the folpet group had significantly lower blood glucose levels than those in the control group. The abundance of Atopobium, Libanicoccus, Collinsella, and Parabacteroides in the intestinal microbiota of folpet-treated mice was significantly higher than that in the control group. However, the abundance of Mailhella, Bilophila, Roseburia, and Bacteroides were reduced in folpet-treated mice. Compared with the control group, the abundance of APH6-Ic and AAC6-Ie-APH2-Ia resistance genes in mice treated with folpet significantly increased. The abundance of tetQ, ermE, and BahA resistance genes was significantly reduced after folpet treatment.

CONCLUSIONS

Folpet is associated with changes in the abundance of gut microbiota in mice and may also affect the abundance of drug-resistance genes and the regulation of blood glucose levels.

Short-chain fatty acids in fetal development and metabolism

Short-chain fatty acids (SCFAs), primarily derived from gut microbiota, play a role in regulating fetal development; however, the mechanism remains unclear. Fetal SCFAs levels depends on maternal SCFAs transported via the placenta. Metabolic stress, particularly from diabetes and obesity, can disrupt maternal SCFAs levels, impairing fetal metabolic reprogramming. Dysregulated SCFAs may negatively impact the development of the fetal cardiovascular, nervous, and immune systems, potentially contributing to adverse outcomes in adulthood. This review focuses on recent advances regarding the role of maternal SCFAs in shaping the metabolic profile of offspring, especially in the context of various maternal metabolic disorders. Given that SCFAs may influence fetal development through the placenta-embryo axis, targeted SCFAs supplementation could be a promising strategy against developmental diseases associated with intrauterine risk factors.

Gut microbiome and Alzheimer's disease: What we know and what remains to be explored

With advancement in human microbiome research, an increasing number of scientific evidences have endorsed the key role of gut microbiota in the pathogenesis of Alzheimer disease. Microbiome dysbiosis, characterized by altered diversity and composition, as well as rise of pathobionts influence not only various gut disorder but also central nervous system disorders such as AD. On the basis of accumulated evidences of past few years now it is quite clear that the gut microbiota can control the functions of the central nervous system (CNS) through the gut-brain axis, which provides a new prospective into the interactions between the gut and brain. The main focus of this review is on the molecular mechanism of the crosstalk between the gut microbiota and the brain through the gut-brain axis, and on the onset and development of neurological disorders triggered by the dysbiosis of gut microbiota. Due to microbiota dysbiosis the permeability of the gut and blood brain barrier is increased which may mediate or affect AD. Along with this, bacterial population of the gut microbiota can secrete amyloid proteins and lipopolysaccharides in a large quantity which may create a disturbance in the signaling pathways and the formation of proinflammatory cytokines associated with the pathogenesis of AD. These topics are followed by a critical analysis of potential intervention strategies targeting gut microbiota dysbiosis, including the use of probiotics, prebiotics, metabolites, diets and fecal microbiota transplantation. The main purpose of this review includes the summarization and discussion on the recent finding that may explain the role of the gut microbiota in the development of AD. Understanding of these fundamental mechanisms may provide a new insight into the novel therapeutic strategies for AD.

Symbiont Acquisition Strategies in Post-Settlement Stages of Two Co-Occurring Deep-Sea Rimicaris Shrimp

At deep-sea hydrothermal vents, deprived of light, most living communities are fueled by chemosynthetic microorganisms. These can form symbiotic associations with metazoan hosts, which are then called holobionts. Among these, two endemic co-occurring shrimp of the Mid-Atlantic Ridge (MAR), Rimicaris exoculata and Rimicaris chacei are colonized by dense and diversified chemosynthetic symbiotic communities in their cephalothoracic cavity and their digestive system. Although both shrimp harbor similar communities, they exhibit widely different population densities, distribution patterns at small scale and diet, as well as differences in post-settlement morphological modifications leading to the adult stage. These contrasting biological traits may be linked to their symbiotic development success. Consequently, key questions related to the acquisition of the symbiotic communities and the development of the three symbiotic organs are still open. Here we examined symbiotic development in juveniles of R. exoculata and R. chacei from TAG and Snake Pit using 16S metabarcoding to identify which symbiotic lineages are present at each juvenile stage. In addition, we highlighted the abundance and distribution of microorganisms at each stage using Fluorescence in situ Hybridization (FISH) and Scanning Electron Microscopy (SEM). For the first time, Candidatus Microvillispirillaceae family with Candidatus Rimicarispirillum spp. (midgut tube), Candidatus Foregutplasma rimicarensis and Candidatus BG2-rimicarensis (foregut) were identified in late juvenile stages. However, these lineages were absent in early juvenile stages, which coincides for the midgut tube with our observations of an immature tissue, devoid of microvilli. Conversely, symbiotic lineages from the cephalothoracic cavity were present from the earliest juvenile stages of both species and their overall diversities were similar to those of adults. These results suggest different symbiont acquisition dynamics between the cephalothoracic cavity and the digestive system, which may also involve distinct transmission mechanisms.

Influence of Early Life Factors on the Breast Milk and Fecal Microbiota of Mother-Newborn Dyads

Maternal gut and breast milk (BM) are key in vertically transmission bacteria to infants, shaping their gut microbiota in early life. Although the establishment of early gut microbiota is known, the role of the combined influence of maternal factors and newborn characteristics is not explored. In this study, we aimed to assess the influence of maternal BMI and total body fat, age, delivery mode, and newborn sex on the diversity and composition of the BM and gut microbiota (GM) in mother-newborn dyads. In this cross-sectional study, of the 986 pregnant women candidates, 53 participated, and, finally, 40 mother-newborn dyads exclusively breastfeeding at 20-28 days postpartum were included. Metataxonomic profiling of DNA extracted from BM and fecal samples was conducted using 16S rRNA sequencing. Globally, the findings offer valuable insights that excessive adiposity, age, and C-section delivery influence a lower abundance of specific taxa in the BM, maternal gut, and gut of newborns. Also, the simultaneous analysis of maternal factors and newborn characteristics shows that maternal age and newborn sex explain an important variation in the microbiota composition. These results add to the understanding of the intricate interplay between maternal factors and the microbial communities that influence early-life gut and BM microbiota.

Calorie restriction during gestation impacts maternal and offspring fecal microbiome in mice

Background

Maternal undernutrition is the most common cause of fetal growth restriction (FGR) worldwide. FGR increases morbidity and mortality during infancy, as well as contributes to adult-onset diseases including obesity and type 2 diabetes. The role of the maternal or offspring microbiome in growth outcomes following FGR is not well understood.

Methods

FGR was induced by 30% maternal calorie restriction (CR) during the second half of gestation in C57BL/6 mice. Pup weights were obtained on day of life 0, 1, and 7 and ages 3, 4 and 16 weeks. Fecal pellets were collected from pregnant dams at gestational day 18.5 and from offspring at ages 3 and 4 weeks of age. Bacterial genomic DNA was used for amplification of the V4 variable region of the 16S rRNA gene. Multivariable associations between maternal CR and taxonomic abundance were assessed using the MaAsLin2 package. Associations between microbial taxa and offspring outcomes were performed using distance-based redundancy analysis and Pearson correlations.

Results

FGR pups weighed about 20% less than controls. Beta but not alpha diversity differed between control and CR dam microbiomes. CR dams had lower relative abundance of Turicibacter, Flexispira, and Rikenella, and increased relative abundance of Parabacteroides and Prevotella. Control and FGR offspring microbiota differed by beta diversity at ages 3 and 4 weeks. At 3 weeks, FGR offspring had decreased relative abundance of Akkermansia and Sutterella and increased relative abundance of Anaerostipes and Paraprevotella. At 4 weeks, FGR animals had decreased relative abundance of Allobaculum, Sutterella, Bifidobacterium, and Lactobacillus, among others, and increased relative abundance of Turcibacter, Dorea, and Roseburia. Maternal Helicobacter abundance was positively associated with offspring weight. Akkermansia abundance at age 3 and 4 weeks was negatively associated with adult weight.

Conclusions

We demonstrate gut microbial dysbiosis in pregnant dams and offspring at two timepoints following maternal calorie restriction. Additional research is needed to test for functional roles of the microbiome in offspring growth outcomes.

Human Evolution, Microgravity, and Challenges Colonizing Mars

INTRODUCTION: Human colonization of Mars has captured the imagination of many. However, the challenges posed are immense. In microgravity, changes in human physiology, immune dysregulation, alterations of our microbiome, and enhanced virulence of various microbes are some of the barriers that stand in the way of a successful endeavor. Countermeasures can be brought to bear, but it remains unclear if success of such a mission in the foreseeable future is realistic or fanciful.Mermel L. Human evolution, microgravity, and challenges colonizing Mars. Aerosp Med Hum Perform. 2024; 95(9):720-721.

Maternal dietary intervention during lactation impacts the maternal faecal and human milk microbiota

AIMS

To determine the effect of a two-week reduced fat and sugar and increased fibre maternal dietary intervention on the maternal faecal and human milk (HM) microbiomes.

METHODS AND RESULTS

Faecal swabs and HM samples were collected from mothers (n = 11) immediately pre-intervention, immediately post-intervention, and 4 and 8 weeks post-intervention, and were analysed using full-length 16S rRNA gene sequencing. Maternal macronutrient intake was assessed at baseline and during the intervention. Maternal fat and sugar intake during the intervention were significantly lower than pre-intervention (P = <0.001, 0.005, respectively). Significant changes in the bacterial composition of maternal faeces were detected after the dietary intervention, with decreases in the relative abundance of Bacteroides caccae (P = <0.001) and increases in the relative abundance of Faecalibacillus intestinalis (P = 0.006). In HM, the diet resulted in a significant increase in Cutibacterium acnes (P = 0.001) and a decrease in Haemophilus parainfluenzae (P = <0.001). The effect of the diet continued after the intervention, with faecal swabs and HM samples taken 4 and 8 weeks after the diet showing significant differences compared to baseline.

CONCLUSION

This pilot study demonstrates that short-term changes in maternal diet during lactation can alter the bacterial composition of the maternal faeces and HM.

Infant age inversely correlates with gut carriage of resistance genes, reflecting modifications in microbial carbohydrate metabolism during early life

The infant gut microbiome is increasingly recognized as a reservoir of antibiotic resistance genes, yet the assembly of gut resistome in infants and its influencing factors remain largely unknown. We characterized resistome in 4132 metagenomes from 963 infants in six countries and 4285 resistance genes were observed. The inherent resistome pattern of healthy infants (N = 272) could be distinguished by two stages: a multicompound resistance phase (Months 0-7) and a tetracycline-mupirocin-β-lactam-dominant phase (Months 8-14). Microbial taxonomy explained 40.7% of the gut resistome of healthy infants, with Escherichia (25.5%) harboring the most resistance genes. In a further analysis with all available infants (N = 963), we found age was the strongest influencer on the resistome and was negatively correlated with the overall resistance during the first 3 years (p < 0.001). Using a random-forest approach, a set of 34 resistance genes could be used to predict age (R 2 = 68.0%). Leveraging microbial host inference analyses, we inferred the age-dependent assembly of infant resistome was a result of shifts in the gut microbiome, primarily driven by changes in taxa that disproportionately harbor resistance genes across taxa (e.g., Escherichia coli more frequently harbored resistance genes than other taxa). We performed metagenomic functional profiling and metagenomic assembled genome analyses whose results indicate that the development of gut resistome was driven by changes in microbial carbohydrate metabolism, with an increasing need for carbohydrate-active enzymes from Bacteroidota and a decreasing need for Pseudomonadota during infancy. Importantly, we observed increased acquired resistance genes over time, which was related to increased horizontal gene transfer in the developing infant gut microbiome. In summary, infant age was negatively correlated with antimicrobial resistance gene levels, reflecting a composition shift in the gut microbiome, likely driven by the changing need for microbial carbohydrate metabolism during early life.

Update on the gut microbiome in health and diseases

The Human Microbiome Project, Earth Microbiome Project, and next-generation sequencing have advanced novel genome association, host genetic linkages, and pathogen identification. The microbiome is the sum of the microbes, their genetic information, and their ecological niche. This study will describe how millions of bacteria in the gut affect the human body in health and disease. The gut microbiome changes in relation with age, with an increase in Bacteroidetes and Firmicutes. Host and environmental factors affecting the gut microbiome are diet, drugs, age, smoking, exercise, and host genetics. In addition, changes in the gut microbiome may affect the local gut immune system and systemic immune system. In this study, we discuss how the microbiome may affect the metabolism of healthy subjects or may affect the pathogenesis of metabolism-generating metabolic diseases. Due to the high number of publications on the argument, from a methodologically point of view, we decided to select the best papers published in referred journals in the last 3 years. Then we selected the previously published papers. The major goals of our study were to elucidate which microbiome and by which pathways are related to healthy and disease conditions.

Life at the borderlands: microbiomes of interfaces critical to One Health

Microbiomes are foundational components of the environment that provide essential services relating to food security, carbon sequestration, human health, and the overall well-being of ecosystems. Microbiota exert their effects primarily through complex interactions at interfaces with their plant, animal, and human hosts, as well as within the soil environment. This review aims to explore the ecological, evolutionary, and molecular processes governing the establishment and function of microbiome-host relationships, specifically at interfaces critical to One Health-a transdisciplinary framework that recognizes that the health outcomes of people, animals, plants, and the environment are tightly interconnected. Within the context of One Health, the core principles underpinning microbiome assembly will be discussed in detail, including biofilm formation, microbial recruitment strategies, mechanisms of microbial attachment, community succession, and the effect these processes have on host function and health. Finally, this review will catalogue recent advances in microbiology and microbial ecology methods that can be used to profile microbial interfaces, with particular attention to multi-omic, advanced imaging, and modelling approaches. These technologies are essential for delineating the general and specific principles governing microbiome assembly and functions, mapping microbial interconnectivity across varying spatial and temporal scales, and for the establishment of predictive frameworks that will guide the development of targeted microbiome-interventions to deliver One Health outcomes.

Metabolic and fecal microbial changes in adult fetal growth restricted mice

BACKGROUND

Fetal growth restriction (FGR) increases risk for development of obesity and type 2 diabetes. Using a mouse model of FGR, we tested whether metabolic outcomes were exacerbated by high-fat diet challenge or associated with fecal microbial taxa.

METHODS

FGR was induced by maternal calorie restriction from gestation day 9 to 19. Control and FGR offspring were weaned to control (CON) or 45% fat diet (HFD). At age 16 weeks, offspring underwent intraperitoneal glucose tolerance testing, quantitative MRI body composition assessment, and energy balance studies. Total microbial DNA was used for amplification of the V4 variable region of the 16 S rRNA gene. Multivariable associations between groups and genera abundance were assessed using MaAsLin2.

RESULTS

Adult male FGR mice fed HFD gained weight faster and had impaired glucose tolerance compared to control HFD males, without differences among females. Irrespective of weaning diet, adult FGR males had depletion of Akkermansia, a mucin-residing genus known to be associated with weight gain and glucose handling. FGR females had diminished Bifidobacterium. Metabolic changes in FGR offspring were associated with persistent gut microbial changes.

CONCLUSION

FGR results in persistent gut microbial dysbiosis that may be a therapeutic target to improve metabolic outcomes.

IMPACT

Fetal growth restriction increases risk for metabolic syndrome later in life, especially if followed by rapid postnatal weight gain. We report that a high fat diet impacts weight and glucose handling in a mouse model of fetal growth restriction in a sexually dimorphic manner. Adult growth-restricted offspring had persistent changes in fecal microbial taxa known to be associated with weight, glucose homeostasis, and bile acid metabolism, particularly Akkermansia, Bilophilia and Bifidobacteria. The gut microbiome may represent a therapeutic target to improve long-term metabolic outcomes related to fetal growth restriction.

Gut microbiota transfer evidence from mother to newborn

Early life microbiota is a risk factor for future diseases. The main purpose of this study was to investigate the transfer of gut microbiota from mother to newborn. A biological sample was collected from the anal mucosa of the pregnant women before delivery and from the newborns between 24 and 48 h after delivery, as it was not possible to collect a meconium sample at that time. The microbiome of the samples was analyzed by sequencing the hypervariable regions V3-V4 of the 16S gene. To determine the likelihood of microbiota transfer from mother to newborn and examine the relationship with the mode of delivery, we utilized Fisher's exact test and odds ratio. A weighted transfer ratio was employed as a comprehensive measure of transfer. A total of 5767 ASVs were identified in newborn samples (n = 30) and 7253 in maternal samples (n = 30). In the analysis of transfer correlated with the mode of delivery, we observed significant ASVs (p < 0.05). Vaginal delivery showed a positive probability of transfer (OR = 2.184 and WTR = 1.852). We found a negative correlation (OR < 1) between the abundance of maternal ASVs and the likelihood of microbiota transfer to the newborn in both delivery modes. The relationship was inversely proportional for both cesarean section (log10 =  - 0.2229) and vaginal delivery (log10 =  - 0.1083), with statistical significance observed only for cesarean section (p = 0.0083).  Conclusion: In our sample, the maternal gut microbiome was found to be associated with the infant gut microbiome, indicating evidence of ASV-specific transfer from the maternal microbiome to newborns. What is Known: • There is a relationship of early-life microbiota composition with future health outcomes. What is New: • This was the first study to evaluate maternal gut microbiota transfer to newborns in Brazil.

Oral lactoferrin administration does not impact the diversity or composition of the infant gut microbiota in a Peruvian cohort

IMPORTANCE

Previous studies have suggested that oral lactoferrin enhances diversity in the gut microbiota in infants while inhibiting the growth of opportunistic pathogens. However, the effect of lactoferrin on infant gut microbiota over time has yet to be thoroughly studied. Our study suggests that lactoferrin oral treatment in infants aged 12-18 months does not affect gut microbiome diversity and composition over time. To our knowledge, this is the first study to report the effect of lactoferrin on infant gut microbiome composition over time and helps elucidate its impact on infant health and its therapeutic potential.

Maternal Vertical Microbial Transmission During Skin-to-Skin Care

BACKGROUND

Skin-to-skin (STS) care may contribute to mother-to-infant vertical microbial transmission by enriching the preterm infant's microbiome.

PURPOSE

The purpose of this observational study was to define the impact of increased STS care duration on vertical microbial transmission and consequently modulate oral and intestinal microbial balance.

METHODS

Postpartum women and their preterm infants, 31 to 34 weeks' gestation (n = 25), were recruited for this study. Using 16S rRNA sequencing, we compared α- and β-diversity with the Shannon and Chao indexes and nonmetric multidimensional scaling, respectively, and relative abundance of microbial communities, which refers to the percentage of specific organisms in a community, from mother's chest skin, preterm infant's oral cavity, and preterm infant's stool samples. Effects of STS care on vertical transmission were determined by comparing oral and stool microbial population of preterm infants who received low exposure (<40 minutes) with that of preterm infants who received high exposure (>60 minutes).

RESULTS

Microbial composition, diversity, and relative abundance were different across the 3 sites. Oral microbial richness was less and stool richness was greater among the preterm infants in the high STS care group. Oral and intestinal microbial diversity and composition were different between the groups, with the relative abundance of Gemella and Aggregatibacter genera and Lachnospiraceae family significantly greater in the stool of the high STS care group.

IMPLICATIONS FOR PRACTICE

Results suggest that STS care may be an effective method to enhance microbial communities among preterm infants.

Early Colonization of the Intestinal Microbiome of Neonatal Piglets Is Influenced by the Maternal Microbiome

The intestinal microbiome plays a crucial role in animal health and growth by interacting with the host, inhibiting pathogenic microbial colonization, and regulating immunity. This study investigated dynamic changes in the fecal microbial composition of piglets from birth through weaning and the relationship between the piglet fecal microbiome and sows. Feces, skin, neonatal oral cavity, and vaginal samples were collected from eight sows and sixty-three piglets, and 16S genome sequencing was performed. The results revealed that Firmicutes, Bacteroidetes, and Proteobacteria dominated the piglet microbiome in the early stages, and Firmicutes and Bacteroidetes were crucial for maintaining a balance in the intestinal microbiome during nursing. The abundance of Christensenellaceae_R-7_group, Succinivibrio, and Prevotella increased in weaned piglets fed solid feed. Analysis of the microbiome from sows to piglets indicated a shift in the microbiome colonizing piglet intestines, which became a significant constituent of the piglet intestinal microbiome. This study supports the theory that the neonatal intestinal microbiome is vertically transmitted from the mother. Further research is required to integrate factors related to sows, piglets, and their environments to gain a better understanding of the early establishment of the intestinal microbiome in piglets.

The Impact of Stress, Microbial Dysbiosis, and Inflammation on Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is the leading cause of intestinal morbidity and mortality in neonates. A large body of work exists; however, the pathogenesis of NEC remains poorly understood. Numerous predictors have been implicated in the development of NEC, with relatively less emphasis on maternal factors. Utilizing human tissue plays a crucial role in enhancing our comprehension of the underlying mechanisms accountable for this devastating disease. In this review, we will discuss how maternal stress affects the pathogenesis of NEC and how changes in the intestinal microbiome can influence the development of NEC. We will also discuss the results of transcriptomics-based studies and analyze the gene expression changes in NEC tissues and other molecular targets associated with the pathogenesis of NEC.

Mechanisms and regulation of defensins in host defense

As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.

Edge and modular significance assessment in individual-specific networks

Individual-specific networks, defined as networks of nodes and connecting edges that are specific to an individual, are promising tools for precision medicine. When such networks are biological, interpretation of functional modules at an individual level becomes possible. An under-investigated problem is relevance or "significance" assessment of each individual-specific network. This paper proposes novel edge and module significance assessment procedures for weighted and unweighted individual-specific networks. Specifically, we propose a modular Cook's distance using a method that involves iterative modeling of one edge versus all the others within a module. Two procedures assessing changes between using all individuals and using all individuals but leaving one individual out (LOO) are proposed as well (LOO-ISN, MultiLOO-ISN), relying on empirically derived edges. We compare our proposals to competitors, including adaptions of OPTICS, kNN, and Spoutlier methods, by an extensive simulation study, templated on real-life scenarios for gene co-expression and microbial interaction networks. Results show the advantages of performing modular versus edge-wise significance assessments for individual-specific networks. Furthermore, modular Cook's distance is among the top performers across all considered simulation settings. Finally, the identification of outlying individuals regarding their individual-specific networks, is meaningful for precision medicine purposes, as confirmed by network analysis of microbiome abundance profiles.

Is there a placental microbiota? A critical review and re-analysis of published placental microbiota datasets

The existence of a placental microbiota is debated. The human placenta has historically been considered sterile and microbial colonization was associated with adverse pregnancy outcomes. Yet, recent DNA sequencing investigations reported a microbiota in typical human term placentas. However, this detected microbiota could represent background DNA or delivery-associated contamination. Using fifteen publicly available 16S rRNA gene datasets, existing data were uniformly re-analyzed with DADA2 to maximize comparability. While Amplicon Sequence Variants (ASVs) identified as Lactobacillus, a typical vaginal bacterium, were highly abundant and prevalent across studies, this prevalence disappeared after applying likely  DNA contaminant removal to placentas from term cesarean deliveries. A six-study sub-analysis targeting the 16S rRNA gene V4 hypervariable region demonstrated that bacterial profiles of placental samples and technical controls share principal bacterial ASVs and that placental samples clustered primarily by study origin and mode of delivery. Contemporary DNA-based evidence does not support the existence of a placental microbiota.ImportanceEarly-gestational microbial influences on human development are unclear. By applying DNA sequencing technologies to placental tissue, bacterial DNA signals were observed, leading some to conclude that a live bacterial placental microbiome exists in typical term pregnancy. However, the low-biomass nature of the proposed microbiome and high sensitivity of current DNA sequencing technologies indicate that the signal may alternatively derive from environmental or delivery-associated bacterial DNA contamination. Here we address these alternatives with a re-analysis of 16S rRNA gene sequencing data from 15 publicly available placental datasets. After identical DADA2 pipeline processing of the raw data, subanalyses were performed to control for mode of delivery and environmental DNA contamination. Both environment and mode of delivery profoundly influenced the bacterial DNA signal from term-delivered placentas. Aside from these contamination-associated signals, consistency was lacking across studies. Thus, placentas delivered at term are unlikely to be the original source of observed bacterial DNA signals.

Childhood Obesity and the Cryptic Language of the Microbiota: Metabolomics’ Upgrading

The growing obesity epidemic in childhood is increasingly concerning for the related physical and psychological consequences, with a significant impact on health care costs in both the short and the long term. Nonetheless, the scientific community has not yet completely clarified the complex metabolic mechanisms underlying body weight alterations. In only a small percentage of cases, obesity is the result of endocrine, monogenic, or syndromic causes, while in much more cases, lifestyle plays a crucial role in obesity development. In this context, the pediatric age appears to be of considerable importance as prevention strategies together with early intervention can represent important therapeutic tools not only to counteract the comorbidities that increasingly affect children but also to hinder the persistence of obesity in adulthood. Although evidence in the literature supporting the alteration of the microbiota as a critical factor in the etiology of obesity is abundant, it is not yet fully defined and understood. However, increasingly clear evidence is emerging regarding the existence of differentiated metabolic profiles in obese children, with characteristic metabolites. The identification of specific pathology-related biomarkers and the elucidation of the altered metabolic pathways would therefore be desirable in order to clarify aspects that are still poorly understood, such as the consequences of the interaction between the host, the diet, and the microbiota. In fact, metabolomics can characterize the biological behavior of a specific individual in response to external stimuli, offering not only an eventual effective screening and prevention strategy but also the possibility of evaluating adherence and response to dietary intervention.

Current and future methods of probiotic therapy for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a complex intestinal disease that primarily affects premature neonates. Given its significant mortality and morbidity, there is an urgent need to develop improved prophylactic measures against the disease. One potential preventative strategy for NEC is the use of probiotics. Although there has been significant interest for decades in probiotics in neonatal care, no clear guidelines exist regarding which probiotic to use or for which patients, and no FDA-approved products exist on the market for NEC. In addition, there is lack of agreement regarding the benefits of probiotics in neonates, as well as some concerns about the safety and efficacy of available products. We discuss currently available probiotics as well as next-generation probiotics and novel delivery strategies which may offer an avenue to capitalize on the benefits of probiotics, while minimizing the risks. Thus, probiotics may still prove to be an effective prevention strategy for NEC, although further product development and research is needed to support use in the preterm population.

Immediate Postnatal Microbial Colonization in Sick Term Neonates Admitted to NICU: Prevalence, Microbiota, and Associated Characteristics

OBJECTIVE

The immediate postnatal rectal (RC) and nasopharyngeal colonization (NPC), their prevalence, taxa, and associated characteristics were investigated in sick term infants admitted to the neonatal intensive care unit.

STUDY DESIGN

In a retrospective cohort single center study, nasopharyngeal (NPCx) and rectal (RCx) microbial cultures were obtained within 20 minutes of birth in mild-to- moderate sick term infants. Associations between the colonization and maternal-neonatal variables, including early neonatal course, were analyzed via logistic regression analysis.

RESULTS

A total of 154 term infants were admitted for respiratory distress, hypoglycemia, maternal chorioamnionitis (CHO), and suspected neonatal sepsis; out of which, 80 (52%) were NPCx-positive (+) infants. The duration of rupture of membrane (ROM) was higher (15.5 ± 10.0 vs. 11.3 ± 11.0 hours, p = 0.02), while the respiratory support requirement (16.3 vs. 29.7%, p = 0.04) and occurrence of maternal group B Streptococcus (GBS) colonization lower (15.0 vs. 35.1%, p = 0.01) in NPCx+ infants. ROM increased (odds ratio [OR]: 1.04, 95% confidence interval [CI]: 1.01-1.07), and maternal GBS colonization decreased the odds of positive nasopharyngeal cultures (OR: 0.31, 95% CI: 0.14-0.72). The major microorganisms isolated were Staphylococcus epidermidis (41%), α hemolytic Streptococcus (AHS; 16%), Escherichia coli (13%), and GBS (1.06%). Among the enrolled infants, 44 (28.5%) were RCx positive. The need for (11.4 vs. 27.3%, p = 0.03) and days on respiratory support (0.2 ± 0.6 vs. 0.8 ± 2.5, p = 0.03) were lower and the occurrence of CHO higher (41.0 vs. 23.2%, p = 0.04) in the RCx positive infants. Cesarean section (CS) was performed less frequently (18.2 vs. 55.5%, p = 0.001) and decreased the odds of having positive rectal cultures (OR: 0.21, 95% CI: 0.08-0.51). In total, 80% of the RCx positive infants isolated E. coli, and 6.8% Klebsiella.

CONCLUSION

In sick term neonates, early NPC is dominated by SE and RC by E. coli. NPC is supported by ROM and declines by maternal GBS colonization, whereas RC decreases with CS. NPC is more common than RC in this population.

KEY POINTS

· Early neonatal nasopharyngeal microbial colonization in sick term neonates, dominated by Staphylococcus epidermidis, is enhanced by the rupture of membrane and diminishes by maternal GBS colonization.. · Cesarean section decreases the rectal colonization, which is composed of E. coli as the predominant microorganism.. · The microbiota of early postnatal colonization in sick term neonates differs from that reported in healthy term infants..

Peri- and Post-natal Risk Factors Associated with Health of Newborns: A pregnant mother's infections and immune diseases, and her baby's delivery method predict immune health of the newborn

Designing prophylactic strategies for newborns requires understanding of the factors that contribute to immunity and resistance to infection. We analyzed 1,892,035 mother-newborn pairs in which both the mother and newborn were observed continuously for at least one year before and after birth. As part of this study, we considered maternal exposures to infections and immune disorders during pregnancy, exposures to anti-infection medications by both mother and newborn, as well as the newborn's delivery type and reported complications. According to our analyses, infection rates and immune disorder rates were over-dispersed among newborns. The most consequential factors predicting newborns' immune health were preterm birth, with 276.3% and 193.9% risk increases for newborn bacterial infections. Newborn anti-infective prescriptions were associated with considerable increases in risk of diseases affecting immune health, while maternal prescriptions were associated with fewer outcomes and with mixed signs. The Cesarean section mode of delivery, the mother's age, the sex of the newborn, and the mother's exposure to infections all showed significant but smaller effects on the newborn's immune health. Female newborn appeared to be better protected against diseases with immune system etiology, except for miscellaneous infections.

Microbiome and Asthma: Microbial Dysbiosis and the Origins, Phenotypes, Persistence, and Severity of Asthma

The importance of the microbiome, and of the gut-lung axis in the origin and persistence of asthma, is an ongoing field of investigation. The process of microbial colonisation in the first three years of life is fundamental for health, with the first hundred days of life being critical. Different factors are associated with early microbial dysbiosis, such as caesarean delivery, artificial lactation and antibiotic therapy, among others. Longitudinal cohort studies on gut and airway microbiome in children have found an association between microbial dysbiosis and asthma at later ages of life. A low α-diversity and relative abundance of certain commensal gut bacterial genera in the first year of life are associated with the development of asthma. Gut microbial dysbiosis, with a lower abundance of Phylum Firmicutes, could be related with increased risk of asthma. Upper airway microbial dysbiosis, especially early colonisation by Moraxella spp., is associated with recurrent viral infections and the development of asthma. Moreover, the bacteria in the respiratory system produce metabolites that may modify the inception of asthma and is progression. The role of the lung microbiome in asthma development has yet to be fully elucidated. Nevertheless, the most consistent finding in studies on lung microbiome is the increased bacterial load and the predominance of proteobacteria, especially Haemophilus spp. and Moraxella catarrhalis. In this review we shall update the knowledge on the association between microbial dysbiosis and the origins of asthma, as well as its persistence, phenotypes, and severity.

Analysis of Fecal Short-Chain Fatty Acids (SCFAs) in Healthy Children during the First Two Years of Life: An Observational Prospective Cohort Study

Short-chain fatty acids (SCFAs) are important metabolites of the gut microbiota. The aim is to analyze the influence of perinatal factors, which can affect the gut microbiota, on the concentrations of fecal SCFAs over the first two years of life. Gas chromatography was used to analyze SCFA in a total of 456 fecal samples from 86 children. Total SCFA concentrations increased until 12 months and stabilized after that. Antibiotic treatment during pregnancy was associated with an increase in acetic acid, propionic acid and total SCFA in meconium and a decrease in the same SCFAs at 6 months. Butyric acid was increased after Caesarean delivery until 1 month. In formula-fed children, propionic acid (at 1 month) and butyric acid and total SCFA (at 12 months) were increased. Acetic and linear butyric acids and total SCFAs were also increased at 12 months in children born vaginally that were also formula-fed. Higher butyric acid was observed in children of mothers with normal pre-pregnancy weight and adequate weight gain during pregnancy. Butyric acid was also elevated in 6-month-old infants with a higher body weight (≥85th percentile). Acetic acid concentrations were significantly higher in 2-year-old females vs. males. We conclude that perinatal factors are linked to changes in fecal SCFAs and further long-term epidemiological studies are warranted.

Study on the relationship between intrapartum group B streptococcus prophylaxis and food allergy in children

Objective

To investigate the associations between intrapartum antibiotic prophylaxis of group B streptococcus (GBS) in pregnant women and the risk of food allergy in Chinese children.

Design

Retrospective cohort study of 2,909 mother-child pairs.

Setting

Taixing People's Hospital in Eastern China.

Participants

Term infants born 2018-2019, followed longitudinally from birth to 3 years.

Exposures

The GBS-IAP was defined as therapy with intravenous penicillin G or ampicillin or cefazolin ≥4 h prior to delivery to the mother. Reference infants were defined as born without or with other intrapartum antibiotic exposure.

Methods

To investigate the incidence information of food allergy in children aged 18 months and three years old. Kaplan-Meier survival analysis and log-rank tests were used to evaluate the cumulative incidence in the group with GBS-IAP and the group without GBS-IAP. Cox proportional hazards models were conducted to determine the univariate and multivariate association between maternal GBS-IAP and incident food allergy after various covariates were adjusted.

Results

The cumulative incidence of food allergy in the group with GBS-IAP was higher than that in the group without GBS-IAP in children under 18 months old (8.1% vs. 4.5%, P = 0.005, log-rank test), but no significant differences were observed in children under three years old (9.2% vs. 7.0%, P = 0.146, log-rank test). The univariate cox proportional hazards model in children under 18 months old revealed that children in the GBS-IAP group had faster food allergy development when compared with children in the group without GBS-IAP (HR.: 1.887,95% CI: 1.207-2.950, P = 0.005), so was the multivariate model (HR.: 1.906,95% CI: 1.158-3.137, P = 0.011). However, both univariate (HR: 1.343, 95% CI: 0.891∼2.026, P = 0.159) and multivariate (HR: 1.253, 95%CI: 0.796∼1.972, P = 0.329) cox proportional hazards model in children under three years old showed no significant differences between children in the group with GBS-IAP and group without GBS-IAP.

Conclusion

Intrapartum antibiotic prophylaxis of group B streptococcus may increase the cumulative incidence and risk of food allergy in children under 18 months old, but it had no significant effect on children under three years old.

Effects of early postnatal life nutritional interventions on immune-microbiome interactions in the gastrointestinal tract and implications for brain development and function

The gastrointestinal (GI) microbiota has co-evolved with the host in an intricate relationship for mutual benefit, however, inappropriate development of this relationship can have detrimental effects. The developing GI microbiota plays a vital role during the first 1,000 days of postnatal life, during which occurs parallel development and maturation of the GI tract, immune system, and brain. Several factors such as mode of delivery, gestational age at birth, exposure to antibiotics, host genetics, and nutrition affect the establishment and resultant composition of the GI microbiota, and therefore play a role in shaping host development. Nutrition during the first 1,000 days is considered to have the most potential in shaping microbiota structure and function, influencing its interactions with the immune system in the GI tract and consequent impact on brain development. The importance of the microbiota-GI-brain (MGB) axis is also increasingly recognized for its importance in these developmental changes. This narrative review focuses on the importance of the GI microbiota and the impact of nutrition on MGB axis during the immune system and brain developmental period in early postnatal life of infants.

Role of gut microbiota in the pathogenesis and treatment of diabetes mullites: Advanced research-based review

Gut microbiota plays an important role in the proper functioning of human organisms, while its dysbiosis is associated with disease in various body organs. Diabetes mellitus (DM) is a set of heterogeneous metabolic diseases characterized by hyperglycemia caused by direct or indirect insulin deficiency. There is growing evidence that gut microbiota dysbiosis is closely linked to the development of DM. Gut microbiota composition changes in type 1 diabetes mullites (T1DM) and type 2 diabetes mullites (T2DM) patients, which may cause gut leakiness and uncontrolled entry of antigens into the circulation system, triggering an immune response that damages the isle β cells or metabolic disorders. This review summarizes gut microbiota composition in healthy individuals and compares it to diabetes mullites patients. The possible pathogenesis by which gut microbiota dysbiosis causes DM, particularly gut leakiness and changes in gut microbiota metabolites is also discussed. It also presents the process of microbial-based therapies of DM.

Biofilm-based delivery approaches and specific enrichment strategies of probiotics in the human gut

The use of probiotics has been one of the effective strategies to restructure perturbed human gut microbiota following a disease or metabolic disorder. One of the biggest challenges associated with the use of probiotic-based gut modulation strategies is to keep the probiotic cells viable and stable during the gastrointestinal transit. Biofilm-based probiotics delivery approaches have emerged as fascinating modes of probiotic delivery in which probiotics show significantly greater tolerance and biotherapeutic potential, and interestingly probiotic biofilms can be developed on food-grade surfaces too, which is ideal for the growth and proliferation of bacterial cells for incorporation into food matrices. In addition, biofilms can be further encapsulated with food-grade materials or with bacterial self-produced biofilms. This review presents a newly emerging and unprecedently discussed techniques for the safe delivery of probiotics based on biofilms and further discusses newly emerging prebiotic materials which target specific gut microbiota groups for growth and proliferation.

Urinary organic acids spectra in children with altered gut microbiota composition and autistic spectrum disorder

Introduction: Alteration of human gut microbiota is described in a number of neuro-developmental and cognitive disorders including autistic spectrum disorder (ASD). Along with the changes in the gut microbiota, children with ASD are also reported to have changes in urinary organic acid spectra implying these metabolites as potential biomarkers for gastrointestinal dysbiosis.Aim: Identify urinary metabolites that would indicate specific changes in the gut microbiota and could be useful as biomarkers.Methods: The study group consisted of 44 children with ASD. Urinary organic acids spectra and composition of gut microbiota were analysed.Results: Any significant deviation in quantified metabolites compared to the reference values were not confirmed. The main variations were detected in concentration of p-cresol and 3-(3-hydroxyphenyl)-3-hydroxypropionic acid (HPHPA), but we cannot confirm the presence of HPHPA in urine as a biomarker for Clostridium sp. overgrowth in the gut. The acquired results indicate higher relative abundance of Firmicutes phylum alone may be attributed to increased concentration of p-cresol in urine. Decreased Bacteroidetes/Firmicutes ratio was found in the group with the presence of HPHPA in urine.Conclusions: Metabolites of human urine can be used as biomarkers for alterations of gut microbiota with caution, guided treatment should be administrated only based on gut microbiota analysis results or in combination with urinary organic acid results, but not solely based on organic acid biomarkers.

Antibiotic knowledge, attitudes and reported practice during pregnancy and six months after birth: a follow- up study in Lao PDR

Background

Antibiotics are important medicines to prevent maternal and child morbidity and mortality. Women’s knowledge and attitudes towards antibiotic use influence their practice. When they become mothers, this may be mirrored in the use of antibiotics for their newborn children. The current study aimed to assess knowledge, attitudes, and reported practice of pregnant women regarding antibiotic use and antibiotic resistance as well as their approach towards antibiotic use for their newborn babies.

Methods

This was a follow-up study with data collected via structured interviews between September 2019 and August 2020 in Feuang (rural) and Vangvieng (urban) districts in Vientiane province, Lao PDR. We identified and invited all women attending antenatal care in their third trimester of pregnancy in the selected areas. Using a structured questionnaire at third trimester of pregnancy we captured data on knowledge regarding antibiotic use and resistance. We collected information on attitudes and reported practice at two time points: (i) at third trimester of pregnancy and (ii) 6 months after birth. Univariate analysis and frequency distributions were used to study pattern of responses. Chi-square and Mann-Whitney tests were used to compare categorical and continuous variables respectively. P value < 0.05 was considered statistically significant.

Results

We surveyed 539 women with a mean age of 25 years. Two oral antibiotics, i) ampicillin and ii) amoxicillin were correctly identified by 68 and 47% of participants respectively. Only 24% of women (19% in Feuang and 29% in Vangvieng) answered correctly that antibiotics are effective against bacterial infections. The most prevalent response was “I don’t know” suggesting the questions were challenging. Significantly less women would use antibiotics from a previous illness for their child than for themselves (16% vs 29%), however they would be more willing to use antibiotics for their baby even in case of mild symptoms (29% vs 17% while pregnant). The majority of antibiotics were prescribed by healthcare providers and 46% of children with the common cold received antibiotics.

Conclusions

Women’s knowledge was sub-optimal, still, they manifested appropriate attitudes towards antibiotic use during pregnancy and for their child. Nearly half of children received antibiotics for the common cold. There is a need for context adapted programs aiming at improving women’s knowledge, as well as healthcare providers, emphasising rational antibiotic prescribing during pregnancy and for children.

Effect of a reduced fat and sugar maternal dietary intervention during lactation on the infant gut microbiome

Objective

A growing body of literature has shown that maternal diet during pregnancy is associated with infant gut bacterial composition. However, whether maternal diet during lactation affects the exclusively breastfed infant gut microbiome remains understudied. This study sets out to determine whether a two-week of a reduced fat and sugar maternal dietary intervention during lactation is associated with changes in the infant gut microbiome composition and function.

Design

Stool samples were collected from four female and six male (n = 10) infants immediately before and after the intervention. Maternal baseline diet from healthy mothers aged 22–37 was assessed using 24-h dietary recall. During the 2-week dietary intervention, mothers were provided with meals and their dietary intake was calculated using FoodWorks 10 Software. Shotgun metagenomic sequencing was used to characterize the infant gut microbiome composition and function.

Results

In all but one participant, maternal fat and sugar intake during the intervention were significantly lower than at baseline. The functional capacity of the infant gut microbiome was significantly altered by the intervention, with increased levels of genes associated with 28 bacterial metabolic pathways involved in biosynthesis of vitamins (p = 0.003), amino acids (p = 0.005), carbohydrates (p = 0.01), and fatty acids and lipids (p = 0.01). Although the dietary intervention did not affect the bacterial composition of the infant gut microbiome, relative difference in maternal fiber intake was positively associated with increased abundance of genes involved in biosynthesis of storage compounds (p = 0.016), such as cyanophycin. Relative difference in maternal protein intake was negatively associated with Veillonella parvula (p = 0.006), while positively associated with Klebsiella michiganensis (p = 0.047). Relative difference in maternal sugar intake was positively associated with Lactobacillus paracasei (p = 0.022). Relative difference in maternal fat intake was positively associated with genes involved in the biosynthesis of storage compounds (p = 0.015), fatty acid and lipid (p = 0.039), and metabolic regulator (p = 0.038) metabolic pathways.

Conclusion

This pilot study demonstrates that a short-term maternal dietary intervention during lactation can significantly alter the functional potential, but not bacterial taxonomy, of the breastfed infant gut microbiome. While the overall diet itself was not able to change the composition of the infant gut microbiome, changes in intakes of maternal protein and sugar during lactation were correlated with changes in the relative abundances of certain bacterial species.

Clinical trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12619000606189).

Stepwise establishment of functional microbial groups in the infant gut between 6 months and 2 years: A prospective cohort study

The early intestinal colonization of functional microbial groups plays an essential role in infant gut health, with most studies targeting the initial colonization period from birth to 6 months of age. In a previous report, we demonstrated the metabolic cross-feeding of lactate and identified keystone species specified for lactate utilization in fecal samples of 40 healthy infants. We present here the extension of our longitudinal study for the period from 6 months to 2 years, with a focus on the colonization of functional groups involved in lactate metabolism and butyrate production. We captured the dynamic changes of the gut microbiota and reported a switch in the predominant lactate-producing and lactate-utilizing bacteria, from Veillonella producing propionate in the first year to Anaerobutyrycum hallii producing butyrate in the second year of life. The significant increase in butyrate producers and fecal butyrate concentration was also pinpointed to the weaning period between 6 and 10 months. Correlation analyses further suggested, for the first time, the metabolic cross-feeding of hydrogen in infants. In conclusion, our longitudinal study of 40 Swiss infants provides important insights into the colonization of functional groups involved in lactate metabolism and butyrate production in the first 2 years of life.

Delivery mode and risk of gastrointestinal disease in the offspring

INTRODUCTION

The global increase of individuals born by cesarean section with reported levels up to 20% of all deliveries, makes it important to study cesarean section and possible associations that can increase risk of subsequent diseases in children. The aim of the study was to evaluate if cesarean section is associated with increased risk of gastrointestinal disease later in life in a large population-based cohort.

MATERIAL AND METHODS

In this national population-based cohort study including all full-term individuals registered in the Medical Birth Register in Sweden between 1990 and 2000, type of delivery (exposure) was collected from the Medical Birth Register. The study population was followed until 2017 with regards to the outcomes: inflammatory bowel disease (Crohn's disease or ulcerative colitis), appendicitis, cholecystitis, or diverticulitis registered in the Swedish National Patient Register. Cox proportional-hazards models compared disease-free survival time between exposed and unexposed.

RESULTS

The final study population consisted of 1 102 468 individuals of whom 11.6% were delivered by cesarean section and 88.4% were vaginally delivered. In univariate analysis, cesarean section was associated with Crohn's disease (hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.02-1.25), diverticulosis (HR 1.57, 95% CI 1.13-2.18), and cholecystitis (HR 1.16, 95% CI 1.05-1.28). However, the increased risk only remained for Crohn's disease after adjustment for confounders (HR 1.14, 95% CI 1.02-1.27). No associations between delivery mode and appendicitis, ulcerative colitis, cholecystitis, or diverticulosis were found in the multivariate analysis.

CONCLUSIONS

Cesarean section is associated with Crohn's disease later in life, but no other association between delivery mode and gastrointestinal disorders later in life could be found.

Breastfeeding and Allergy Effect Modified by Genetic, Environmental, Dietary, and Immunological Factors

Breastfeeding (BF) is the most natural mode of nutrition. Its beneficial effect has been revealed in terms of both the neonatal period and those of lifelong effects. However, as for protection against allergy, there is not enough data. In the current narrative review, the literature within the last five years from clinical trials and population-based studies on breastfeeding and allergy from different aspects was explored. The aim of this review was to explain how different factors could contribute to the overall effect of BF. Special consideration was given to accompanying exposure to cow milk, supplement use, the introduction of solid foods, microbiota changes, and the epigenetic function of BF. Those factors seem to be modifying the impact of BF. We also identified studies regarding BF in atopic mothers, with SCFA as a main player explaining differences according to this status. Conclusion: Based on the population-based studies, breastfeeding could be protective against some allergic phenotypes, but the results differ within different study groups. According to the new research in that matter, the effect of BF could be modified by different genetic (HMO composition), environmental (cesarean section, allergen exposure), dietary (SCFA, introduction of solid food), and immunologic factors (IgG, IgE), thus partially explaining the variance.

Neuroprotective Role of Lactoferrin during Early Brain Development and Injury through Lifespan

Early adverse fetal environments can significantly disturb central nervous system (CNS) development and subsequently alter brain maturation. Nutritional status is a major variable to be considered during development and increasing evidence links neonate and preterm infant impaired brain growth with neurological and psychiatric diseases in adulthood. Breastfeeding is one of the main components required for healthy newborn development due to the many "constitutive" elements breastmilk contains. Maternal intake of specific nutrients during lactation may alter milk composition, thus affecting newborn nutrition and, potentially, brain development. Lactoferrin (Lf) is a major protein present in colostrum and the main protein in human milk, which plays an important role in the benefits of breastfeeding during postnatal development. It has been demonstrated that Lf has antimicrobial, as well as anti-inflammatory properties, and is potentially able to reduce the incidence of sepsis and necrotizing enterocolitis (NEC), which are particularly frequent in premature births. The anti-inflammatory effects of Lf can reduce birth-related pathologies by decreasing the release of pro-inflammatory factors and inhibiting premature cervix maturation (also related to commensal microbiome abnormalities) that could contribute to disrupting brain development. Pre-clinical evidence shows that Lf protects the developing brain from neuronal injury, enhances brain connectivity and neurotrophin production, and decreases inflammation in models of perinatal inflammatory challenge, intrauterine growth restriction (IUGR) and neonatal hypoxia-ischemia (HI). In this context, Lf can provide nutritional support for brain development and cognition and prevent the origin of neuropsychiatric diseases later in life. In this narrative review, we consider the role of certain nutrients during neurodevelopment linking to the latest research on lactoferrin with respect to neonatology. We also discuss new evidence indicating that early neuroprotective pathways modulated by Lf could prevent neurodegeneration through anti-inflammatory and immunomodulatory processes.

Review article: Epidemiology of coeliac disease

Coeliac disease is an immune-mediated disease caused by ingestion of gluten in genetically susceptible individuals. Coeliac disease has been thought to affect mainly people of European origin but subsequently many studies revealed that it affects people living in North America, Oceania, South America, Asia as well as Africa. The global pooled seroprevalence and prevalence of biopsy-confirmed coeliac disease are 1.4% and 0.7% respectively. The pooled incidence rates in women and men are 17.4 (95% CI: 13.7-21.1) and 7.8 (95% CI: 6.3-9.2) per 100 000 person-years respectively. The systematic reviews, based on many population-based data, suggest that both the prevalence and the incidence of coeliac disease has increased over past three decades, which may be attributable not only to an increase in the detection rate (improvement in diagnostic tests, simplification of diagnostic criteria and increase in awareness about the disease) but also because of modernisation and globalisation related changes in the dietary practices including increase in the use of convenience food and dietary gluten. In addition to genetic factors, while there are many environmental risk factors, including age at the first introduction of gluten, breastfeeding, caesarean section, exposure to antibiotics and gut microbiome; the amount of gluten ingestion during early part of life, however, has been shown to increase the risk of coeliac disease, and this is relevant from the point of view of primary prevention. In this review, we have reviewed and summarised the literature, up till year 2021, related to the global and continent-wise epidemiology and risk factors associated with coeliac disease.

Metagenomics Approaches to Investigate the Neonatal Gut Microbiome

Early infancy is critical for the development of an infant's gut flora. Many factors can influence microbiota development during the pre- and postnatal periods, including maternal factors, antibiotic exposure, mode of delivery, dietary patterns, and feeding type. Therefore, investigating the connection between these variables and host and microbiome interactions in neonatal development would be of great interest. As the "unculturable" era of microbiome research gives way to an intrinsically multidisciplinary field, microbiome research has reaped the advantages of technological advancements in next-generation sequencing, particularly 16S rRNA gene amplicon and shotgun sequencing, which have considerably expanded our knowledge about gut microbiota development during early life. Using omics approaches to explore the neonatal microbiome may help to better understand the link between the microbiome and newborn diseases. Herein, we summarized the metagenomics methods and tools used to advance knowledge on the neonatal microbiome origin and evolution and how the microbiome shapes early and late individuals' lives for health and disease. The way to overcome limitations in neonatal microbiome studies will be discussed.

Human milk microbiota: what did we learn in the last 20 years?

Human milk (HM) is the gold standard for infant nutrition during the first months of life. Beyond its nutritional components, its complex bioactive composition includes microorganisms, their metabolites, and oligosaccharides, which also contribute to gut colonization and immune system maturation. There is growing evidence of the beneficial effects of bacteria present in HM. However, current research presents limited data on the presence and functions of other organisms. The potential biological impacts on maternal and infant health outcomes, the factors contributing to milk microbes' variations, and the potential functions in the infant's gut remain unclear. This review provides a global overview of milk microbiota, what the actual knowledge is, and what the gaps and challenges are for the next years.

The Impact of Escherichia coli Probiotic Strain O83:K24:H31 on the Maturation of Dendritic Cells and Immunoregulatory Functions In Vitro and In Vivo

Early postnatal events are important for the development of the neonatal immune system. Harboring the pioneering microorganisms forming the microbiota of the neonatal gastrointestinal tract is important for priming the immune system, as well as inducing appropriate tolerance to the relatively innocuous environmental antigens and compounds of normal healthy microbiota. Early postnatal supplementation of suitable, safe probiotics could accelerate this process. In the current study, the immunomodulatory capacity of the probiotic strain of Escherichia coli O83:K24:H31 (EcO83) was characterized in vitro and in vivo. We compared the capacity of EcO83 with and without hemolytic activity on selected immune characteristics in vitro as determined by flow cytometry and quantitative real-time PCR. Both strains with and without hemolytic activity exerted comparable capacity on the maturation of dendritic cells while preserving the induction of interleukin 10 (Il10) expression in dendritic cells and T cells cocultured with EcO83 primed dendritic cells. Early postnatal supplementation with EcO83 led to massive but transient colonization of the neonatal gastrointestinal tract, as detected by in vivo bioimaging. Early postnatal EcO83 administration promoted gut barrier function by increasing the expression of claudin and occludin and the expression of Il10. Early postnatal EcO83 application promotes maturation of the neonatal immune system and promotes immunoregulatory and gut barrier functions.

Increased fecal human beta-defensin-2 expression in preterm infants is associated with allergic disease development in early childhood

Background

This study aimed to investigate whether fecal human beta-defensins (HBD)-2 and eosinophil cationic protein (ECP) expression in preterm infants are associated with allergic disease development by age 2 years.

Methods

Preterm infants' stool samples were collected at the age of 6 and 12 months postnatally. Information regarding medication exposure histories (antibiotics, antipyretics, probiotics) and physician-diagnosed allergic diseases was obtained using age-specific questionnaires and medical records. We compared the 6-month and 12-month fecal HBD-2 and ECP concentrations between the medication exposure and non-exposure group, respectively, and between children who developed allergic diseases and those who did not by 2 years of age. Univariate and multivariable logistic regression analyses were performed to investigate independent variables related to physician-diagnosed allergic diseases by 2 years of age.

Results

Seventy-four preterm infants (gestational age, 31–36 weeks) were included. Fecal HBD-2 levels were significantly increased at 12 months of age among children who developed allergic diseases compared to those who did not (37.18 ± 11.80 ng/g vs. 8.56 ± 4.33 ng/g, P = 0.011). This association was more apparent among allergic children given antibiotics (50.23 ± 16.15 ng/g vs. 9.75 ± 7.16 ng/g, P = 0.008) or antipyretics (46.12 ± 14.22 ng/g vs. 10.82 ± 6.81 ng/g, P = 0.018) during the first year, whereas among allergic children who were previously not exposed to antibiotics or antipyretics, the differences were not significant. Results of the multivariable logistic regression analysis indicated that HBD-2 concentration in 12-month stools was an independent indicator associated with physician-diagnosed allergic diseases by 2 years of age (adjusted odds ratio: 1.03 [95% confidence interval: 1.00–1.05], P = 0.036). Our data revealed a lack of association between fecal ECP and allergic diseases.

Conclusions

We found that preterm infants who expressed high fecal HBD-2 at 12 months of age were associated with physician-diagnosed allergic diseases by the age of 2 years. Further studies are needed to determine the role of fecal HBD-2 in the development of allergic diseases.