Relationship between gastrointestinal disturbances, blood lipid levels, inflammatory markers, and preterm birth

BACKGROUND

The challenging incidence of preterm birth, the underlying causes of preterm birth remain unclear. This study determined the relationship between disturbed gastrointestinal symptoms, inflammatory markers, blood lipid levels, and preterm birth.

METHOD

One hundred and twenty pregnant women with preterm labour were compared to 120 pregnant women with full-term deliveries. All subjects underwent lactose breath and serologic testing. The correlation between small intestinal bacterial overgrowth (SIBO)-positivity, gastrointestinal symptoms, inflammatory factors, and blood lipid metabolism and preterm birth was analysed using the Spearman method.

RESULTS

SIBO, hydrogen, and methane levels were significantly higher in the preterm birth (PTB) group than the full-term birth (FTB) group at different time points (P < 0.05); Levels of high-sensitivity C-reactive protein (hs-CRP) (3.95[2.70-5.77] vs. 2.47[1.45-3.83]), Interleukin (IL)-10 (3.05[2.27-4.33] vs. 2.09[1.04-3.47]), IL-6 (5.23[3.95-8.50] vs. 2.98[2.22-4.44]), tumour necrosis factor -alpha (TNF-α) (3.23[1.55-4.90] vs. 1.76[0.98-3.10]), total cholesterol (TC) (5.52[4.97-5.95] vs. 5.24[4.73-5.85]), and triglycerides (TG) (2.58[2.04-3.53] vs. 2.24[1.59-3.05]) were significantly higher in the PTB group than the FTB group (P < 0.05). Abdominal distension (2.67[1.67-3.00] vs. 2.33[1.67-2.67]) and constipation (2.00[1.33-2.00] vs. 1.67[1.33-2.00]) scores were also markedly higher in the PTB group than the FTB group (P < 0.05). Preterm birth was positively correlated with SIBO, TC, and TG levels. Additionally, SIBO was positively correlated with hs-CRP, IL-10, IL-6, and TNF-α levels, abdominal distension, and constipation (P < 0.05). Logistic regression analysis found the close association between positive SIBO, biochemistry indicators and preterm birth.

CONCLUSION

Gastrointestinal disturbances, hyperlipidaemia and SIBO-positivity are more likely to occur among pregnant women with preterm labour. Further research with a large sample size in multi-centers is needed to validate the results.

Maternal consumption of urbanized diet compromises early-life health in association with gut microbiota

Urbanization has significantly transformed dietary habits worldwide, contributing to a globally increased burden of non-communicable diseases and altered gut microbiota landscape. However, it is often overlooked that the adverse effects of these dietary changes can be transmitted from the mother to offspring during early developmental stages, subsequently influencing the predisposition to various diseases later in life. This review aims to delineate the detrimental effects of maternal urban-lifestyle diet (urbanized diet) on early-life health and gut microbiota assembly, provide mechanistic insights on how urbanized diet mediates mother-to-offspring transfer of bioactive substances in both intrauterine and extrauterine and thus affects fetal and neonatal development. Moreover, we also further propose a framework for developing microbiome-targeted precision nutrition and diet strategies specifically for pregnant and lactating women. The establishment of such knowledge can help develop proactive preventive measures from the beginning of life, ultimately reducing the long-term risk of disease and improving public health outcomes.

Neonatal microbiota colonization primes maturation of goblet cell-mediated protection in the pre-weaning colon

Regulated host-microbe interactions are a critical aspect of lifelong health. Colonic goblet cells protect from microorganisms via the generation of a mucus barrier structure. Bacteria-sensing sentinel goblet cells provide secondary protection by orchestrating mucus secretion when microbes breach the mucus barrier. Mucus deficiencies in germ-free mice implicate a role for the microbiota in programming barrier generation, but its natural ontogeny remains undefined. We now investigate the mucus barrier and sentinel goblet cell development in relation to postnatal colonization. Combined in vivo and ex vivo analyses demonstrate rapid and sequential microbiota-dependent development of these primary and secondary goblet cell protective functions, with dynamic changes in mucus processing dependent on innate immune signaling via MyD88 and development of functional sentinel goblet cells dependent on the NADPH/dual oxidase family member Duox2. Our findings identify new mechanisms of microbiota-goblet cell regulatory interaction and highlight the critical importance of the pre-weaning period for the normal development of protective systems that are key legislators of host-microbiota interaction.

Zinc amino acid chelate and the Aryl Hydrocarbon Receptor (AHR) cooperate in improving the barrier function of a Caco-2 cell intestinal epithelium

Zinc and several physiologically relevant ligands of the aryl hydrocarbon receptor (AHR) are nutrients that promote intestinal barrier function. We have identified that AHR activation upregulates the expression of zinc importers in the intestinal epithelium to increase intracellular zinc concentrations, which leads to improved epithelial barrier function. Here, we investigated if an amino acid chelate of zinc, in cooperation with AHR activation, can improve the barrier function of a differentiated Caco-2 cell epithelium. Functional assays of the Caco-2 cell epithelium demonstrate that both ZnSO4 and a lysine and glutamic acid chelate of Zn, in combination with the physiological AHR agonist 6-formylindolo[3,2-b]carbazole (FICZ), increase expression of tight junction proteins at the mRNA and protein levels. FICZ increases uptake of zinc into the epithelium in the presence of ZnSO4 or the amino acid Zn chelate in the medium to equal extents. We conclude that the lysine and glutamic acid chelate of Zn is as efficacious as ZnSO4 in reducing permeability of the Caco-2 cell epithelium in the presence of FICZ. The results suggest that dietary supplementation with bioavailable forms of zinc together with nutritional AHR agonists may be beneficial in improving gut barrier function and help prevent inflammatory bowel disease (IBD).

Lifelong partners: Gut microbiota-immune cell interactions from infancy to old age

Our immune system and gut microbiota are intricately coupled from birth, both going through maturation during early life and senescence during aging almost in a synchronized fashion. The symbiotic relationship between the human host and microbiota is critically dependent on a healthy immune system to keep our microbiota in check, while the microbiota provides essential functions to promote the development and fitness of our immune system. The partnership between our immune system and microbiota is particularly important during early life, when microbial ligands and metabolites shape the development of the immune cells and immune tolerance; during aging, having sufficient beneficial gut bacteria is critical for the maintenance of intact mucosal barriers, immune metabolic fitness, and strong immunity against pathogens. The immune system during childhood is programmed, with the support of the microbiota, to develop robust immune tolerance, and limit autoimmunity and metabolic dysregulation, which are prevalent during aging. This review comprehensively explores the mechanistic underpinnings of gut microbiota-immune cell interactions during infancy and old age, with the goal to gain a better understanding of potential strategies to leverage the gut microbiota to combat age-related immune decline.

Maternal β-carotene supplementation improves offspring growth, development, immunity, and intestinal microbiota in chickens via immune-mediated and microbial-mediated maternal effects

In poultry, maternal nutritional interventions affect the development and intestinal microbiota of embryos. β-carotene possesses immune-boosting and gut microbiota-regulating properties. We examined the influences of supplementing hen diets with β-carotene on offspring growth, development, and immunity to determine whether maternal β-carotene benefits offspring health. Our findings showed that β-carotene increased serum IgG, lysozyme, and beta-defensins in hens, subsequently elevated these parameters in the serum of their offspring, and promoted their growth and development. In offspring, there were significant positive correlations between body weights and intestinal development indices with serum lysozyme and beta-defensin levels. The augmentation of vertical transfer of lysozyme and beta-defensins may be linked to the increased expression of these genes in the maternal jejunum. The number of shared taxa between the magnum and offspring gut is higher than that between the maternal gut and offspring. Among the taxa, were increased in the maternal magnum and gut microbiome, only the Caloramator abundance was significantly elevated in the guts of 21-day-old offspring. In conclusion, maternal β-carotene inclusion improves offspring growth and development, potentially through enhancing maternal intestinal immunity and thereby promoting immune-mediated maternal effects. The vertical transfer of maternal microbes to offspring exhibits selectivity in chicken.

Impact of antimicrobial exposure at delivery and siblings on early Bifidobacterium succession and allergy development up to 24 months of age

BACKGROUND

Allergic diseases such as asthma, eczema, and food allergies are rising globally. The infant gut microbiota, particularly the dominance of Bifidobacterium, shapes immune development and allergy risk. In Japan-where Bifidobacterium prevalence is notably high-longitudinal investigations focusing on the pre-weaning period, when external influences are relatively limited, remain scarce. Therefore, based on consistent hypotheses and findings from previous studies, we investigated how two important early factors-antibiotic exposure at birth and the presence of older siblings-influence the gut environment in early infancy and subsequent allergy development.

RESULTS

In a prospective cohort of 121 Japanese infants, stool samples were collected at seven time points from birth through 24 months. We quantified the relative abundances of Bifidobacterium, Bacteroides, Clostridium, and Faecalibacterium and recorded allergic outcomes at 2 years. Both antimicrobial exposure at delivery and sibling presence significantly altered gut microbiota composition and overall diversity in early infancy. Although the full cohort showed no consistent diversity or Bifidobacterium differences by allergic status, in several subgroups where these two factors were excluded, infants who had an allergy by 24 months exhibited marked shifts in early gut microbiota community structure-particularly in beta diversity-and reduced Bifidobacterium occupancy during the pre-weaning period (1-6 months) versus non-allergic peers. Moreover, infants whose gut microbiota was initially affected by these factors showed a recovery in diversity after weaning, a rebound more pronounced in non-allergic individuals.

CONCLUSIONS

These findings indicate that both the initial community configuration and its capacity to rebound after perturbation are critical determinants of allergy risk. By focusing on dynamic changes through weaning and adjusting for decisive confounders, this study refines insight beyond prior cross-sectional work. Early interventions that preserve or restore microbial diversity and Bifidobacterium dominance may therefore offer a promising strategy to mitigate allergic disease development.

Association of maternal dietary diversity during pregnancy and infant lower respiratory tract infections

BACKGROUND

A varied diet during pregnancy benefits development of the fetus, but its impact on the infant respiratory health is less well-known. This study prospectively examines the association between the maternal Minimum Dietary Diversity for Women (MDD-W) score and the risk of lower respiratory tract infections (LRTIs) in infants.

METHODS

This study included 2588 women in Wuhan, China. Dietary intake was assessed using validated food frequency questionnaires. All food items were categorized into 10 groups based on guidance from the Food and Agriculture Organization to construct the MDD-W score. Infant LRTIs were recorded at 3-, 6-, and 12-months postpartum follow-ups.

RESULTS

In the study, 347 (13.4%) infants with LRTIs during the first year. Maternal MDD-W score ≤5 was associated with the higher risk of infant LRTIs (RR: 1.51; 95% CI: 1.11, 2.06) and hospitalization due to LRTIs (RR: 1.93; 95% CI: 1.23, 3.05) compared score ≥9. When the outcome was further subdivided into LRTIs at 0-6 months and 6-12 months of age, this association was only present at 0-6 months of age (RR: 2.02; 95% CI: 1.31, 3.10).

CONCLUSIONS

Our results suggest that low maternal dietary diversity is associated with a higher risk of infant LRTIs.

IMPACT

Diversified diet during pregnancy benefits the fetus's development, but few studies have demonstrated the effect of dietary diversity during pregnancy on the infant respiratory health. In this longitudinal cohort in China, we found that a varied diet during pregnancy was associated with a lower risk of infant lower respiratory tract infections, the association remained regardless of whether infants breastfed. An intervention to increase maternal dietary diversity should be carefully considered.

Exposure of infants to antibiotics via cord blood, breast milk, and formula: A review on exposure level, temporal variation, and risk assessment

The pervasive use of antibiotics across various sectors, including agriculture, medicine, and aquaculture, has led to a notable increase in environmental antibiotic residues. This phenomenon has raised significant public concern regarding the potential health risks antibiotics may pose, particularly to vulnerable populations such as infants. However, the conceptualization of exposure routes of antibiotics to infants and the associated health risks has not been conducted. This review summarized three main pathways infants are exposed to antibiotics, including umbilical cord blood, breast milk, and infant formula. Antibiotic exposure levels in infants were synthesized, examining spatial and temporal trends in antibiotic concentrations across different media through clinical testing. We also analyzed the doses of antibiotics consumed by infants over time through breast milk and formula, evaluating the associated risks. Furthermore, we explored the potential adverse effects of early-life antibiotic exposure on the infant gut microbiota, physical development, and multiple organ systems. Given the global significance of antibiotic distribution, it is pertinent to comprehensively monitor antibiotic concentrations in infants and conduct longitudinal follow-up studies on their growth and development, accurately quantifying and assessing the impacts on fetal and infant health.

Maternal obesity and offspring metabolism: revisiting dietary interventions

Maternal obesity increases the risk of metabolic disorders in offspring. Understanding the mechanisms underlying the transgenerational transmission of metabolic diseases is important for the metabolic health of future generations. More research is needed to elucidate the mechanisms underlying the associated risks and their clinical implications because of the inherently complex nature of transgenerational metabolic disease transmission. Diet is a well-recognized risk factor for the development of obesity and other metabolic diseases, and rational dietary interventions are potential therapeutic strategies for their prevention. Despite extensive research on the physiological effects of diet on health and its associated mechanisms, little work has been devoted to understanding the effects of early-life dietary interventions on the metabolic health of offspring. In addition, existing dietary interventions are insufficient to meet clinical needs. Here, we discuss the literature on the effects of maternal obesity on the metabolic health of offspring, focusing on the mechanisms underlying the transgenerational transmission of metabolic diseases. We revisit current dietary interventions and describe their strengths and weaknesses in ameliorating maternal obesity-induced metabolism-related disorders in offspring. We also propose innovative strategies, such as the use of precision nutrition and fecal microbiota transplantation, which may limit the vicious cycle of intergenerational metabolic disease transmission.

Maternal gut microbiota influences immune activation at the maternal-fetal interface affecting pregnancy outcome

Preeclampsia is a leading cause of morbidity and mortality in pregnant women, affecting 5-8% of gestations worldwide. Its development is influenced by maternal immune abnormalities, metabolic disorders, and gut dysbiosis. In this study, we show that gut dysbiosis in pregnant C57BL/6J dams leads to increased fetal resorption, impaired placental development and altered vascularization. These adverse outcomes are associated with key pathological features of preeclampsia, including hypoxia, endoplasmic reticulum (ER) stress and reduction in uterine natural killer (NK) cell numbers. Furthermore, gut dysbiosis significantly perturbs placental carbohydrate metabolism, which impairs NK cell IFN-γ secretion. Notably, glucose supplementation restores placental NK cell function and reduces fetal resorption, suggesting that the observed impairment is reversible and dependent on a lower glycolytic rate. These findings highlight maternal gut microbiota as a key player in carbohydrate metabolism, with a pivotal role in modulating placental immunity and pregnancy outcome. The results provide valuable insights into potential metabolic biomarkers and suggest that targeting the gut microbiota may offer a strategy for preventing preeclampsia.

Self or nonself: end of a dogma?

Immunologists generally view the notion of self and non-self as part of a broader, more contextual understanding of immune function, rather than a rigid dogma. While the classical paradigm that the primary role of the immune system is to recognize and eliminate anything foreign once provided a unifying basis for explaining tolerance and rejection, numerous discoveries have focused attention on how immune responses are finely tuned by a range of contextual cues, including tissue signals, hygienist theory, molecular mimicry, symbiotic microbes, metabolic factors and epigenetic modifications. Maternal-fetal tolerance and the persistence of microchimeric cells in adults demonstrate that genetically foreign cells can be actively integrated into the host, challenging the simple assumption that 'foreign' equals unconditional attack. Similarly, research into the microbiome, the virome and the phenomenon of trained innate immunity has shown that there can be beneficial or even essential relationships between the body and what has traditionally been labelled 'non-self'. Over the last decade, the idea that the immune system strictly enforces a binary distinction has instead evolved towards a model in which it continuously interprets signals of damage or perturbation, manages complex ecological relationships with commensal or latent organisms, and recalibrates according to the organism's life stage and environment. There remains a recognition that clonal deletion and negative selection in the thymus, together with MHC-bound peptide recognition, still underlie many core processes, and in certain clinical contexts, such as acute transplant rejection or the prevention of autoimmunity, an approximate self-non-self-categorization is directly relevant. Overall, however, the field recognizes that 'self' is not a static attribute defined once and for all, but rather a dynamic and context-dependent state that continues to be shaped by microbial symbioses, epigenetic reprogramming and immunoregulatory networks throughout an individual's lifespan.

In utero human intestine contains maternally derived bacterial metabolites

BACKGROUND

Understanding when host-microbiome interactions are first established is crucial for comprehending normal development and identifying disease prevention strategies. Furthermore, bacterially derived metabolites play critical roles in shaping the intestinal immune system. Recent studies have demonstrated that memory T cells infiltrate human intestinal tissue early in the second trimester, suggesting that microbial components such as peptides that can prime adaptive immunity and metabolites that can influence the development and function of the immune system are also present in utero. Our previous study reported a unique fetal intestinal metabolomic profile with an abundance of several bacterially derived metabolites and aryl hydrocarbon receptor (AHR) ligands implicated in mucosal immune regulation.

RESULTS

In the current study, we demonstrate that a number of microbiome-associated metabolites present in the fetal intestines are also present in the placental tissue, and their abundance is different across the fetal intestine, fetal meconium, fetal placental villi, and the maternal decidua. The fetal gastrointestinal samples and maternal decidua samples show substantially higher positive correlation on the abundance of these microbial metabolites than the correlation between the fetal gastrointestinal samples and meconium samples. The expression of genes associated with the transport and signaling of some microbial metabolites is also detectable in utero.

CONCLUSIONS

We suggest that the microbiome-associated metabolites are maternally derived and vertically transmitted to the fetus. Notably, these bacterially derived metabolites, particularly short-chain fatty acids and secondary bile acids, are likely biologically active and functional in regulating the fetal immune system and preparing the gastrointestinal tract for postnatal microbial encounters, as the transcripts for their various receptors and carrier proteins are present in second trimester intestinal tissue through single-cell transcriptomic data. Video Abstract.

Trace Element Exposure during Pregnancy Has a Persistent Influence on Perinatal Gut Microbiota in Mother-Infant Dyads

Trace elements have been recognized as the modifiers of the gut microbiota. However, population-based evidence about their effects on maternal gut microbiota dynamics, as well as the intergenerational impacts on neonatal gut microbiota, has been lacking. We examined the longitudinal microbiota data from mother-infant dyads and demonstrated that maternal trace element exposure played a pivotal role in shaping the composition and similarity of the mother-infant gut microbiota. Specifically, serum levels of cobalt (Co), molybdenum (Mo), and rubidium (Rb) were identified to cause further fluctuation in the shift of the maternal gut microbiota. Antibiotic usage shortly before or on the delivery day, as well as maternal zinc (Zn) exposure, affected the gut microbiota similarity within mother-infant dyads. Rb demonstrated an intergenerational effect on meconium Bifidobacterium abundance by altering its abundance in the maternal gut. Notably, this effect was strengthened in the vaginal delivery group without antibiotic usage, while it was attenuated in the c-section delivery group. Our results suggest that maternal trace element exposure has a persistent influence on perinatal gut microbiota, which offers novel insights into promoting mother and infant health.

Alterations of the paired maternal fecal microbiota and neonatal meconium microbiota in newborns from pregnant women with hypertensive disorders

Background

Hypertensive disorders of pregnancy (HDP) pose significant risks to both maternal and fetal health and have been associated with alterations in the maternal gut microbiota. However, the impact of HDP on neonatal microbiota remains poorly understood. This study aimed to characterize the gut microbiota of pregnant women with HDP and evaluate its potential influence on the meconium microbiota of their newborns.

Methods

A cohort of 67 pregnant women, including 36 diagnosed with HDP (HDP group) and 31 healthy, age-matched controls (HC group), along with their offspring, were recruited. Fecal samples collected during the third trimester and meconium samples from the newborns were subjected to microbial community profiling via 16S rRNA gene sequencing.

Results

Principal coordinate analysis (PCoA) based on Bray-Curtis distances revealed significant differences in microbial community composition between the HDP and HC groups in both maternal and neonatal samples. Subgroup analyses, stratified by HDP severity and medication use, further delineated distinct microbial profiles relative to controls. Notably, both maternal and neonatal microbiota in the HDP group exhibited increased abundances of Enterobacter, Klebsiella, and Sphingomonas, coupled with a reduction in Acidovorax, Azospirillum, Caulobacter, Flavobacterium, Magnetospirillum, and Rubrivivax compared to the HC group. Moreover, the P4-PWY pathway, which is involved in the biosynthesis of L-lysine, L-threonine, and L-methionine, was differentially represented in both maternal and neonatal microbiota in the HDP group. These parallel patterns suggest an intergenerational concordance associated with HDP.

Conclusion

This study demonstrates significant alterations in the microbial communities of both maternal fecal and neonatal meconium samples in the context of HDP. The findings highlight the importance of further research to elucidate the long-term health implications of HDP-associated microbiota shifts on offspring.

Maternal Administration of Probiotics Augments IL17-Committed γδ T Cells in the Newborn Lung

The early life period is increasingly being recognized as a window of opportunity to shape immunity, where microbiota and related probiotics have an important impact. Innate γδ T cells are the first T cells generated in utero, populating epithelial tissues such as the lung and contributing to tissue protection through, for example, IL17 production. Here, we studied the influence of maternal microbiota and probiotic supplementation during pregnancy on innate γδ T cells in the lung and thymus of newborn mice. Detailed time-kinetic experiments showed that at birth, the murine lung T cell population was specifically dominated by IL17-committed γδ T cells expressing an invariant Vγ6Vδ1 TCR. Single-cell RNA-sequencing showed that the biased IL17-commitment of perinatal lung γδT cells is highly conserved between mice and humans. While maternal microbiota depletion with antibiotics tended to decrease the frequency of the lung Vγ6 T cells of the offspring at birth, the maternal administration of Lacticaseibacillus rhamnosus (L.rhm.), but not of Bifidobacterium animalis subsp. lactis (B.lac.), increased significantly their frequency, resulting in the augmentation of the IL17-commitment of the mouse lung T cell compartment. Altogether, our data indicate that the maternal microbiota contributes to the shaping of IL17-committed γδT cells in the lungs of newborns and that maternal administration of specific probiotic strains can enhance this process.

The Janus-facedness of the aryl hydrocarbon receptor pathway Report of the 6th International AHR Meeting: Research, Prevention, Therapy

The ability to sense and process environmental cues is a fundamental aspect of an organism's biology. The evolutionary ancient transcription factor AHR (aryl hydrocarbon receptor) has evolved in animals to sense low molecular weight compounds derived from environmental exposure, dietary plants, the gut/skin microbiome, or generated endogenously from tryptophan upon ultraviolet light (UV) exposure or enzymatic catabolism. The binding of such molecules results in a cascade of events leading to the transcription of target genes. The AHR gene locus was first identified in mice in 1982. Since then, the beneficial and detrimental effects of AHR agonist-driven activation or lack thereof have been studied, particularly in relation to environmental chemical toxicity, carcinogenicity, or tissue homeostasis, e.g. barrier tissues. AHR ligands are also being considered as a potential new therapeutic class of molecules for the treatment of cancer, debilitating and chronic inflammatory diseases or metabolic disorders. A series of international meetings initiated twenty years ago have provided a comprehensive overview of AHR research. At the meeting in Düsseldorf in 2024, the identification of tailor-made ligands using modern, artificial intelligence (AI)-based approaches was a key topic of discussion, as were current attempts to resolve the dual nature of AHR activation - beneficial and harmful. While our understanding is still in its infancy, research was also presented that highlights previously unrecognized roles of the AHR in many diseases.

The reality of modeling irritable bowel syndrome: progress and challenges

INTRODUCTION

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that is often therapeutically challenging. While research has advanced our understanding of IBS pathophysiology, developing precise models to predict drug response and treatment outcomes remains a significant hurdle.

AREAS COVERED

This perspective provides an overview of the use of animal models alongside cutting-edge technologies used to bring drugs from bench to bedside.Furthermore, the authors examine the progress and limitations of IBS modeling. The authors further discuss the challenges of traditional animal models and gives a spotlight to the potential of innovative technologies, such as organ-on-chip systems, computational models, and artificial intelligence (AI). These approaches intend to enhance both the understanding and treatment of IBS.

EXPERT OPINION

Although animal models have been central to understanding IBS research, they have limitations. The future of IBS research resides in integrating organ-on-chip systems and utilizing modern technological developments, such as AI. These tools will enable the design of more effective treatment strategies and improve patients' overall well-being. To achieve this, collaboration between experts from various disciplines is essential to improve these models and guarantee their clinical application and reliability.

Impact of maternal obesity and mode of delivery on the newborn skin and oral microbiomes

Introduction. Previous studies have shown vast differences in the skin and oral microbiomes of newborns based on delivery method [Caesarean section (C-section) vs vaginal]. Exposure to or absence of certain bacteria during delivery can impact the neonate's future susceptibility to infections, allergies or autoimmunity by altering immune functions. Few studies have focused on the impact of maternal obesity on the variations of newborn skin and oral microbiomes. Obese pregnant women typically have a higher vaginal microbiome diversity, and their pregnancies are at higher risk for adverse outcomes and complications.Hypothesis. We hypothesized that the skin and oral microbiomes of newborns born to obese mothers would include more diverse, potentially pathogenic bacteria and that the skin and oral microbiome in C-section delivered newborns would be less diverse than vaginally delivered newborns.Aim. We aim to begin to establish maternal obesity and mode of delivery as factors contributing to increased risk for negative newborn outcomes through impacts on newborn bacterial dysbiosis.Methodology. A skin swab was collected immediately following delivery of 39 newborns from 13 healthy weight body mass index (BMI 18.50-24.99), 11 overweight (BMI 25.0-29.99) and 15 obese (BMI ≥30.00) pregnant participants. An oral swab was collected immediately following delivery for 38 of these newborns from 13 healthy weight, 10 overweight and 15 obese pregnant participants. Bacterial genera were identified via 16S rRNA amplicon sequencing.Results. The newborn skin microbiome was comprised of typical skin bacteria (i.e. Corynebacterium). Newborns of obese participants had a higher relative abundance of Peptoniphilus in their skin microbiome compared to newborns of healthy weight participants (P=0.007). Neonates born via C-section had a higher relative abundance of Ureaplasma in their oral microbiome compared to neonates delivered vaginally (P=0.046).Conclusion. We identified differences in the newborn skin and oral microbiomes based on pre-pregnancy BMI and method of delivery. These differences could be linked to an increased risk of allergies, autoimmune disease and infections. Future longitudinal studies will be crucial in determining the long-term impact of these specific genera on newborn outcomes. Understanding these connections could lead to targeted interventions that reduce the risk of adverse outcomes and improve overall health trajectory.

Physiological and Microbial Community Dynamics in Does During Mid-Gestation to Lactation and Their Impact on the Growth, Immune Function, and Microbiome Transmission of Offspring Kids

This study investigated changes in physiological processes and rumen microbial communities in does from mid-gestation to lactation and identified potential associations between these physiological changes and the rumen microbiome. Additionally, we studied the transmission mechanisms of microorganisms between the dam and offspring. Our study demonstrates significant changes in maternal physiological metabolism, immune status, and rumen microbiota from mid-pregnancy through lactation. We identified potential associations between these physiological changes and the rumen microbiome. Moreover, the findings highlight that alterations in maternal physiological metabolism and immune status significantly influence the growth and immune development of offspring kids. Additionally, we observed that the maternal microbiota serves as a key source of gastrointestinal microbial communities in young animals, with early colonization of maternally derived microbes in the offspring's gastrointestinal tract playing a role in shaping their immune system development. The results for primary outcomes are as follows: The serum levels of estrogen and progesterone in pregnant does were greater than those observed during lactation, while the concentration of growth hormone, triiodothyronine, and glucose exhibited an upward trend during lactation. During late gestation, the serum IL-10 concentration in does decreased, while the TNF-α concentration increased. Additionally, on day 140 of gestation, does showed a significant decrease in IgG, total protein, and globulin levels. From mid-gestation to lactation, the abundance of dominant phyla and genera, including Firmicutes, Bacteroidetes, Patescibacteria, Bacteroidales_RF16_group, Clostridia_UCG-014, RF39, and Eubacterium_ventriosum_group, in the rumen of does underwent significant changes. LEfSe analysis identified a series of marker microorganisms in the rumen of does at different physiological stages. A correlation was observed between these dominant bacteria and the serum physiological indicators of the does. Notably, rumen volatile fatty acids also exhibited a correlation with serum physiological indicators. In addition, serum physiological indicators of does were significantly correlated with the growth and immune indicators of their kids. Microbiological origin analysis revealed that the gastrointestinal microbiome of kids primarily originated from the rumen, birth canal, and milk of does. Further analysis identified a correlation between the kids' serum immunometric indicators and certain gastrointestinal microorganisms. In particular, the jejunum microbiota of 28-day-old lactating kids, including Alysiella, Neisseria, and Muribaculaceae, showed a significant positive correlation with serum IL-6 and IL-10 levels. Meanwhile, these genera were dominant in the saliva and milk of does, suggesting a direct microbial transfer from dam to offspring. These microbial communities may play a significant role in modulating the metabolism and immune responses of the offspring, thereby influencing their immune system development.

Characterizing the prevalence of Fusobacterium necrophorum subsp. necrophorum, Fusobacterium necrophorum subsp. funduliforme, and Fusobacterium varium in bovine and ovine semen, bovine gut, and vagino-uterine and fetal microbiota using targeted culturing and qPCR

Fusobacterium necrophorum is an important pathogen associated with several infectious diseases in cattle. However, recent sequencing-based studies reported that F. necrophorum may be positively associated with pregnancy in beef cows and that Fusobacterium is highly abundant in bull seminal microbiota with potential involvement in reproductive health and fertility. Here, we performed a comprehensive screening to (i) determine the prevalence of Fusobacterium necrophorum (subspecies necrophorum [FNN] and funduliforme [FNF]) and Fusobacterium varium (FV) in the reproductive microbiota of cattle and sheep as well as bovine digestive tract ecosystems, and (ii) explore whether these Fusobacterium spp. colonize calf prenatally. For this, we screened 11 different sample types including bovine and ram semen, bovine vaginal and uterine swabs, and bull fecal samples, as well as samples from 180- and 260-day-old calf fetuses and their respective dams using both quantitative PCR (qPCR; 514 samples) and targeted culturing (499 samples). By qPCR, all the targeted Fusobacterium spp. were detected across all sample types with varying prevalence rates and viability. FNF was highly prevalent in the bull semen (66.7%) and maternal ruminal fluids (87.1%), and its viability was confirmed through culturing. All the targeted Fusobacterium spp. were identified in vaginal and uterine swab samples (3.1%-9.4%), caruncles, fetal fluids, rumen, and meconium samples (2.7%-26.3%) by qPCR but were not isolated by culture method. Overall, our results, for the first time, suggest that F. necrophorum is a commensal member of healthy male reproductive microbiota, and that FNF, FNN, and FV are present in bovine vagino-uterine microbiota and calf intestine prenatally.IMPORTANCERecent sequencing-based studies suggest that Fusobacterium, including F. necrophorum, a known primary etiological agent for several important infectious diseases in cattle, may be non-pathogenic members of the reproductive microbiota with pro-fertility effects. However, further information regarding the absolute abundance, viability, and higher taxonomic resolution of the Fusobacterium species and subspecies which cannot be achievable by the amplicon sequencing approach is needed to confirm the commensal and non-pathogenic status of the Fusobacterium spp. in cattle. Here, we performed a comprehensive screening of F. necrophorum subspecies necrophorum, F. necrophorum subspecies funduliforme, and Fusobacterium varium from over 500 samples from 11 different sample types using targeted culturing and qPCR. Overall, our results provide novel insights into the prevalence and viability of Fusobacterium spp. in bovine male and female reproductive tracts and their presence in calf fetuses, which will serve as the basis for further research into understanding the role of Fusobacterium in cattle fertility.

High-Fat Diet and Altered Radiation Response

High-fat diets (HFDs) have become increasingly prevalent in modern societies, driving rising rates of obesity and metabolic syndrome. Concurrently, radiation exposure from medical treatments and environmental sources poses health risks shaped by both biological and environmental factors. This review explores the intersection between HFDs and radiation sensitivity/susceptibility, focusing on how diet-induced metabolic alterations influence the body's response to radiation. Evidence from preclinical and clinical studies indicates that HFDs significantly alter metabolism, leading to increased oxidative stress and immune system dysregulation. These metabolic changes can exacerbate radiation-induced oxidative stress, inflammation, and DNA damage, potentially increasing radiation sensitivity in normal tissues. Conversely, obesity and HFD-induced metabolic disruptions may activate cellular pathways involved in DNA repair, cell survival, and inflammatory responses, fostering tumor resistance and modifying the tumor microenvironment, which may impair the efficacy of radiation therapy in cancer treatment. Understanding the interplay between diet and radiation exposure is critical for optimizing public health guidelines and improving therapeutic outcomes. These findings underscore the need for further research into dietary interventions that may mitigate radiation-associated risks.

Mutual Interactions Between Microbiota and the Human Immune System During the First 1000 Days of Life

The development of the human immune system starts during the fetal period in a largely, but probably not completely, sterile environment. During and after birth, the immune system is exposed to an increasingly complex microbiota. The first microbiota encountered during passage through the birth canal colonize the infant gut and induce the tolerance of the immune system. Transplacentally derived maternal IgG as well as IgA from breast milk protect the infant from infections during the first 100 days, during which the immune system further develops and immunological memory is formed. The Weaning and introduction of solid food expose the immune system to novel (food) antigens and allow for other microbiota to colonize. The cells and molecules involved in the mutual and intricate interactions between microbiota and the developing immune system are now beginning to be recognized. These include bacterial components such as polysaccharide A from Bacteroides fragilis, as well as bacterial metabolites such as the short-chain fatty acid butyrate, indole-3-aldehyde, and indole-3-propionic acid. All these, and probably more, bacterial metabolites have specific immunoregulatory functions which shape the development of the human immune system during the first 1000 days of life.

Disruption and adaptation: infant gut microbiota's dynamic response to SARS-CoV-2 infection

BACKGROUND

The responses of the infant gut microbiota to infection significantly disrupt the natural intrahost evolutionary processes of the microbiome. Here, we collected a 16-month longitudinal cohort of infant gut microbiomes affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Then, we developed a multicriteria approach to identify core interaction network driving community dynamics under environmental disturbances, which we termed the Conserved Variated Interaction Group (CVIgroup).

RESULTS

The CVIgroup showed significant advantages on pinpointing a sparse set associated with the disturbances, as validated both our own and publicly available datasets. Leveraging the Oxford Nanopore Technology, we found this group facilitates the ecosystem's adaptation to environmental disruptions by enhancing the mobility of mobile genetic elements, including the reinforcement of the twin-arginine translocation pathway in response to increased virulence factors. Furthermore, the CVIgroup serves as an effective indicator of ecosystem health. The timescale for the gut microbiota's adaptation extends beyond 10 months. Members of the CVIgroup, such as Bacteroides thetaiotaomicron and Faecalibacterium, exhibit varying degrees of genomic structural variants, which contribute to guiding the community toward a new stable state rather than returning to its original configuration.

CONCLUSIONS

Collectively, the CVIgroup offers a snapshot of the gut microbiota's adaptive response to environmental disturbances. The disruption and subsequent adaptation of the gut microbiota in infants after COVID-19 infection underscores the necessity of re-evaluating reference standards in the context of the post-pandemic era. Video Abstract.

Gut microbiota and other factors associated with increased T cell regulation in HIV-exposed uninfected infants

Introduction

Infants exposed to HIV and uninfected (HEUs) are at higher risk of infectious morbidity than HIV-unexposed uninfected infants (HUUs). Multiple immune defects of unknown origin were observed in HEUs. We hypothesized that HEUs have more regulatory and inhibitory checkpoint-expressing T cells (Treg, Tici) than HUUs, which may dampen their immune defenses against pathogens.

Method

We used flow cytometry to measure 25 Treg/Tici subsets in HEUs and HUUs at birth, 6, 28, and 62 weeks of life. We used maternal and infant gut microbiome data reported in a previous study to establish correlations with the Treg/Tici.

Results

At birth, 3 Treg subsets, including the prototypic CD4+FOXP3+ and CD4+FOXP3+CD25+, had higher frequencies in 123 HEUs than in 117 HUUs, and 3 subsets had higher frequencies in HUUs. At 28 and 62 weeks of age, 5 Treg/Tici subsets had higher proportions in HEUs than HUUs. The frequencies of the Treg/Tici subsets that diverged between HEUs and HUUs at birth correlated with differential relative abundances of bacterial taxa in the maternal gut microbiome. The Treg/Tici subsets with significantly different frequencies at subsequent visits correlated with the concurrent composition of the infant gut microbiome. In vitro, treatment of HUU peripheral blood mononuclear cells (PBMC) with bacterial taxa most abundant in HEUs expanded Treg/Tici subsets with higher frequencies in HEUs than HUUs, recapitulating the in vivo correlations. Conversely, in vitro treatment of HEU PBMC did not increase Treg/Tici frequencies. Other factors that correlated with increased Treg/Tici frequencies were low maternal CD4+ T cells in HEUs at birth and male sex in the HUUs at 28 weeks of life.

Discussion

This study shows that maternal and infant gut dysbiosis are central to the increase in Treg/Tici in HEUs and may be targeted by mitigating interventions.

Interactions of the maternal microbiome with diet, stress, and infection influence fetal development

Humans and other animals contain multitudes of microorganisms including bacteria, fungi, and viruses, which make up a diverse microbiome. Across body sites including skin, gastrointestinal tract, and oral cavity there are distinct microbial niches that are made up of trillions of microorganisms that have co-evolved to inhabit and interact with the host. The microbiome also interacts with the changing environment. This tripartite interaction between the host, microbiome, and environment suggests microbial communities play a key role in the biological processes of the host, such as development and behaviors. Over the past two decades, emerging research continues to reveal how host and microbe interactions impact nervous system signaling and behaviors, and influence neurodevelopmental, neurological, and neurodegenerative disorders. In this review, we will describe the unique features of the maternal microbiome that exist during the perinatal period and discuss evidence for the function of the maternal microbiome in offspring development. Finally, we will discuss how the maternal environment interacts with the microbiome and nervous system development and then postulate how the maternal microbiome can modify early offspring development to have lasting influence on brain health.

The role of the gut microbiota in regulating responses to vaccination: current knowledge and future directions

Antigen-specific B and T cell responses play a critical role in vaccine-mediated protection against infectious diseases, but these responses are highly variable between individuals and vaccine immunogenicity is frequently sub-optimal in infants, the elderly and in people living in low- and middle-income countries. Although many factors such as nutrition, age, sex, genetics, environmental exposures, and infections may all contribute to variable vaccine immunogenicity, mounting evidence indicates that the gut microbiota is an important and targetable factor shaping optimal immune responses to vaccination. In this review, we discuss evidence from human, preclinical and experimental studies supporting a role for a healthy gut microbiota in mediating optimal vaccine immunogenicity, including the immunogenicity of COVID-19 vaccines. Furthermore, we provide an overview of the potential mechanisms through which this could occur and discuss strategies that could be used to target the microbiota to boost vaccine immunogenicity where it is currently sub-optimal.

Early life factors, diet and microbiome, and risk of inflammatory bowel disease

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), result from a loss of immune tolerance to gut microbiota, leading to inflammation. Their incidence is increasing, especially in newly industrialized countries. The etiology is multifactorial, involving genetic, immune, microbiota, and environmental factors. Maternal microbiome changes during pregnancy can elevate IBD risk in offspring, influenced by diet, smoking, and antibiotic exposure. Early life microbiota manipulation shows promise for preventing IBD. Epidemiological and pre-clinical studies highlight diet's significant role in IBD development. High-inflammatory dietary patterns correlate with increased CD risk, while Mediterranean-like diets promote beneficial gut microbiome changes and reduce inflammation. Certain food additives, such as emulsifiers and artificial sweeteners, may exacerbate IBD by altering gut microbiota. A systematic review indicates that higher ultra-processed food consumption significantly increases CD risk. Lifestyle modifications, including healthy dietary adherence, could substantially reduce IBD risk, with studies showing that favorable choices can halve the risk in genetically predisposed individuals. Additionally, maternal diet impacts offspring IBD risk, as seen in mouse models where high-fat diets led to increased inflammation. Evidence suggests that maternal probiotics and specific dietary patterns may mitigate these risks. Overall, these findings emphasize the potential for dietary interventions to modulate gut microbiota and immune responses, offering promising avenues for IBD prevention and management. Further large-scale studies are needed to explore the impact of dietary strategies on IBD risk and gut health.

Neonatal microbiome in the multiomics era: development and its impact on long-term health

The neonatal microbiome has been the focus of considerable research over the past two decades and studies have added fascinating information in terms of early microbial patterns and how these relate to various disease processes. One difficulty with the interpretation of these relationships is that such data is associative and provides little in terms of proof of causality or the underpinning mechanisms. Integrating microbiome data with other omics such as the proteome, inflammatory mediators, and the metabolome is an emerging approach to address this gap. Here we discuss these omics, their integration, and how they can be applied to improve our understanding, treatment, and prevention of disease. IMPACT: This review introduces the concept of multiomics in neonatology and how emerging technologies can be integrated improve understanding, treatment, and prevention of disease. We highlight considerations for performing multiomic research in neonates and the need for validation in separate cohorts and/or relevant model systems. We summarise how the use of multiomics is expanding and lay out steps to bring this to the clinic to enable precision medicine.

Microbial metabolism of food allergens determines the severity of IgE-mediated anaphylaxis

Anaphylaxis is an acute, potentially life-threatening reaction, often triggered by foods and largely mediated by IgE. A critically important aspect of anaphylaxis pertains to the factors that modulate its severity. The human microbiota is known to influence oral tolerance, but the microbial mechanisms directly involved in IgE-mediated anaphylaxis remain unknown. Here, we demonstrate that human saliva harbors peanut-degrading bacteria that metabolize immunodominant allergens (Ara h 1 and Ara h 2) and alter IgE binding. Additionally, we provide in vivo evidence showing that oral bacteria metabolize peanut allergens, influencing systemic allergen exposure and the severity of anaphylaxis. Finally, in a clinical study, we observe that common peanut-degrading bacteria, such as Rothia, from the oral cavity, are more abundant in peanut-allergic patients who exhibit better tolerance to allergen exposure. Altogether, these results demonstrate the role of the human microbiota in modulating IgE-mediated reactions through allergen metabolism. These findings reveal a novel microbial mechanism with potential to prevent, or reduce, the severity of IgE-mediated anaphylaxis.

The microbiome as a modulator of neurological health across the maternal-offspring interface

The maternal microbiome is emerging as an important factor that influences the neurological health of mothers and their children. Recent studies highlight how microbial communities in the maternal gut can shape early-life development in ways that inform long-term health trajectories. Research on the neurodevelopmental effects of maternal microbiomes is expanding our understanding of the microbiome-gut-brain axis to include signaling across the maternal-offspring unit during the perinatal period. In this Review, we synthesize existing literature on how the maternal microbiome modulates brain function and behavior in both mothers and their developing offspring. We present evidence from human and animal studies showing that the maternal microbiome interacts with environmental factors to impact risk for neurodevelopmental abnormalities. We further discuss molecular and cellular mechanisms that facilitate maternal-offspring crosstalk for neuromodulation. Finally, we consider how advancing understanding of these complex interactions could lead to microbiome-based interventions for promoting maternal and offspring health.

Gut IgA functionally interacts with systemic IgG to enhance antipneumococcal vaccine responses

The gut microbiota enhances systemic immunoglobulin G (IgG) responses to vaccines, but it is unknown whether this effect involves IgA, which coats intestinal microbes. That IgA may amplify postimmune IgG production is suggested by the impaired IgG response to pneumococcal vaccines in some IgA-deficient patients. Here, we found that antipneumococcal but not total IgG production was impaired in mice with IgA deficiency. The positive effect of gut IgA on antipneumococcal IgG responses started very early in life and could implicate gut bacteria, as these responses were attenuated in germ-free mice recolonized with gut microbes from IgA-deficient donors. IgA could exert this effect by constraining the systemic translocation of gut antigens, which was associated with chronic immune activation, including T cell overexpression of programmed cell death protein 1 (PD-1). This inhibitory receptor may attenuate antipneumococcal IgG production by causing B cell hyporesponsiveness, which improved upon anti-PD-1 treatment. Thus, gut IgA functionally interacts with systemic IgG to enhance antipneumococcal vaccine responses.

The Neonatal Microbiome: Implications for Amyotrophic Lateral Sclerosis and Other Neurodegenerations

Most brain development occurs in the "first 1000 days", a critical period from conception to a child's second birthday. Critical brain processes that occur during this time include synaptogenesis, myelination, neural pruning, and the formation of functioning neuronal circuits. Perturbations during the first 1000 days likely contribute to later-life neurodegenerative disease, including sporadic amyotrophic lateral sclerosis (ALS). Neurodevelopment is determined by many events, including the maturation and colonization of the infant microbiome and its metabolites, specifically neurotransmitters, immune modulators, vitamins, and short-chain fatty acids. Successful microbiome maturation and gut-brain axis function depend on maternal factors (stress and exposure to toxins during pregnancy), mode of delivery, quality of the postnatal environment, diet after weaning from breast milk, and nutritional deficiencies. While the neonatal microbiome is highly plastic, it remains prone to dysbiosis which, once established, may persist into adulthood, thereby inducing the development of chronic inflammation and abnormal excitatory/inhibitory balance, resulting in neural excitation. Both are recognized as key pathophysiological processes in the development of ALS.

Roughage Sources During Late Gestation and Lactation Alter Metabolism, Immune Function and Rumen Microbiota in Ewes and Their Offsprings

Maternal metabolic intensity significantly increases during late gestation and lactation, placing significant stress on cells and tissues. This heightened metabolic demand can lead to inflammatory responses and metabolic disorders, adversely affecting the health of both the mother and her offspring. Diet plays a key role in modulating host health by influencing the gastrointestinal microbiome. This study examined the impact of two roughage sources, corn straw (CS), and alfalfa hay (AH), on ewes and their offspring during late gestation and lactation, with a focus on metabolism, immunity, and the microbiome. Thirty-six multiparous Inner Mongolia cashmere goats, approximately 60 days pregnant, were assigned to CS and AH groups. Samples were collected from the ewes on day 140 of gestation (G140) and day 28 of lactation (L28) for analysis. The results showed that ewes fed AH had reduced body weight loss during lactation (p < 0.05), and increased serum metabolic factors levels (p < 0.05). Additionally, ewes in the AH group exhibited a reduced inflammatory response during both gestation and lactation compared to those in the CS group, as evidenced by a significant decrease in TNF-α and LPS levels and a notable increase in IL-10 (p < 0.05). The rumen microbiomes of ewes in the AH and CS groups exhibited stark differences, with specific microbial markers identified at G140 and L28. Correlation analysis revealed associations between microbiome, volatile fatty acids, cytokines, and metabolic markers. The analysis of the lambs demonstrated that their immune status and microbial composition were significantly influenced by the immune health and microbial community structure of the ewe. Moreover, microbial and immune-related components from the ewes were transmitted to the lambs, further shaping their immune development and rumen microbiota. Overall, different roughage sources during late gestation and lactation had minimal impact on the growth performance of ewes and lambs, given that both diets were iso-nitrogen and iso-energetic. However, ewes fed AH exhibited significant improvements in immune function and overall health for both them and their lambs.

The essential role of prebiotics in restoring gut health in long COVID

The gut microbiota (GM) plays an essential role in human health, influencing not only digestive processes but also the immune system´s functionality. The COVID-19 pandemic has highlighted the complex interaction between viral infections and the GM. Emerging evidence has demonstrated that SARS-CoV-2 can disrupt microbial homeostasis, leading to dysbiosis and compromised immune responses. The severity of COVID-19 has been associated with a reduction in the abundance of several beneficial bacteria in the gut. It has been proposed that consuming probiotics may help to re-colonize the GM. Although probiotics are important, prebiotics are essential for their metabolism, growth, and re-colonization capabilities. This chapter delves into the critical role of prebiotics in restoring GM after COVID-19 disease. The mechanisms by which prebiotics enhance the metabolism of beneficial bacteria will be described, and how prebiotics mediate the re-colonization of the gut with beneficial bacteria, thereby restoring microbial diversity and promoting the resilience of the gut-associated immune system. The benefits of consuming prebiotics from natural sources are superior to those from chemically purified commercial products.

Maternal gut microbiota influence stem cell function in offspring

The maternal microbiome influences child health. However, its impact on a given offspring's stem cells, which regulate development, remains poorly understood. To investigate the role of the maternal microbiome in conditioning the offspring's stem cells, we manipulated maternal microbiota using Akkermansia muciniphila. Different maternal microbiomes had distinct effects on proliferation and differentiation of neuronal and intestinal stem cells in the offspring, influencing their developmental trajectory, physiology, and long-term health. Transplantation of altered maternal microbiota into germ-free mice transmitted these stem cell phenotypes to the recipients' offspring. The progeny of germ-free mice selectively colonized with Akkermansia did not display these stem cell traits, emphasizing the importance of microbiome diversity. Metabolically more active maternal microbiomes enriched the levels of circulating short-chain fatty acids (SCFAs) and amino acids, leaving distinct transcriptomic imprints on the mTOR pathway of offsprings' stem cells. Blocking mTOR signaling during pregnancy eliminated the maternal-microbiome-mediated effects on stem cells. These results suggest a fundamental role of the maternal microbiome in programming offsprings' stem cells and represent a promising target for interventions.

Approaching the sterile womb theory in dogs and cats: A multi-technique investigation

The study investigated whether bacterial seeding occurs in utero in dogs and cats using a multi-technique approach, including 16S rRNA gene sequencing, culture, and fluorescence in situ hybridization (FISH). Healthy pregnant bitches and queens (n = 8) undergoing ovariohysterectomy between 30 and 45 days of gestation were included. Placenta and amniotic fluid samples from two foetuses per dam, along with multiple controls (uterine serosa, sampling table, and surgeon's gloves), were collected and analysed. Bacterial sequences were detected in all foetal samples, with no significant differences in intra- and inter-sample diversity (i.e., alpha and beta diversities, respectively) based on sample type or species. However, the surgeon's gloves showed species-specific differences in bacterial composition. After removing control sequences, significant differences based on foeto-maternal units emerged. Moraxella spp. was cultured from the canine placenta with the highest bacterial load, and Burkholderia cepacia was isolated from two feline placentae. FISH showed low bacterial presence in 50 % of placentae without histological signs of inflammation. No bacterial growth was observed in amniotic fluid or control samples. A multi-technique approach, including multiple controls, is essential in studies involving low-biomass samples, as the results of the present study indicated that contamination could mask real bacterial composition of foetal samples. After decontamination, differences were observed based on the foeto-maternal unit. This study confirmed the presence of bacterial DNA in placental and amniotic fluid samples during mid-term, healthy pregnancies in dogs and cats. Bacterial DNA is not equivalent to living bacteria, hence bacterial DNA fragments in the uterus probably originate from the dam but are unlikely to indicate the presence of a resident foetal microbiome.

Shaping immunity: the influence of the maternal gut bacteria on fetal immune development

The development of the fetal immune response is a highly complex process. In the present review, we describe the development of the fetal immune response and the role of the maternal gut bacteria in this process. In contrast to the previous belief that the fetal immune response is inert, it is now thought that the fetal immune response is uniquely tolerant to maternal and allo-antigens, but able to respond to infectious agents, such as bacteria. This is accomplished by the development of T cells toward regulatory T cells rather than toward effector T cells, but also by the presence of functional innate immune cells, such as monocytes and NK cells. Moreover, in fetuses there is different programming of CD8 + T cells and memory T cells toward innate immune cells rather than to adaptive immune cells. The maternal gut bacteria are important in shaping the fetal immune response by producing bacterial products and metabolites that pass the placenta into the fetus and influence development of the fetal immune response. Insight into how and when these products affect the fetal immune response may open new treatment options with pre- or probiotics to affect the maternal gut bacteria and therewith the fetal immune response.

The Changes of Lymphocytes and Immune Molecules in Irradiated Mice by Different Doses of Radiation

ABSTRACT

The effects of different radiation doses on T and B lymphocyte functional subsets and the changes of immune cells and immune molecules were observed in mice at different times post-irradiation to provide a theoretical basis for the changes of immune cells affected by radiation. In this study, the changes of T and B immune cells and immune-related molecules were observed at 1, 3, 7, 14, and 21 d after single irradiation of 2 Gy, 4 Gy, and 6 Gy. The results showed that white blood cells (WBC), lymphocytes (LYMPH), and lymphocyte percentage (LYMPH%) in peripheral blood of mice were significantly reduced and reached the lowest point 3 d after irradiation. Flow cytometry results showed that the percentages of CD3+T and CD8+/CD3+T lymphocytes in spleen and thymus were significantly decreased, and the percentages of CD19+B lymphocytes in spleen and CD4+/CD3+T lymphocytes in thymus were also decreased. However, the percentages of splenic NK cells, CD4+/CD3+T cells, and CD4+/CD8+ ratios in spleen and thymus were increased. Most of the indicators fell to the lowest or highest point 3 d after irradiation, indicating that immune function was suppressed at this time. From 7 to 21 d after irradiation, most immune cells gradually recovered. Single irradiation of 2 Gy, 4 Gy, and 6 Gy increased the contents of IL-1β, IL-2, IL-6, IL-17, TNF-α, TGF-β, and IFN-γ in serum of mice and decreased the contents of anti-inflammatory factors IL-4 and IL-10. The serum levels of immunoglobulin IgA, IgG, IgM and complement C3, C4 were significantly increased after irradiation. Our study showed that a single dose of 2 Gy, 4 Gy, and 6 Gy induced immunosuppression in mice, and maximum immunosuppression was achieved 3 d after irradiation. At this time, CD19+B lymphocytes were the most sensitive, followed by CD3+T lymphocytes, and NK cells were the most resistant. The radiosensitivity of CD8+/CD3+T lymphocytes was slightly higher than that of CD4+/CD3+T lymphocytes.

The Interplay of Nutrition, the Gut Microbiota and Immunity and Its Contribution to Human Disease

Nutrition, the gut microbiota and immunity are all important factors in the maintenance of health. However, there is a growing realization of the complex interplay between these elements coalescing in a nutrition-gut microbiota-immunity axis. This regulatory axis is critical for health with disruption being implicated in a broad range of diseases, including autoimmune disorders, allergies and mental health disorders. This new perspective continues to underpin a growing number of innovative therapeutic strategies targeting different elements of this axis to treat relevant diseases. This review describes the inter-relationships between nutrition, the gut microbiota and immunity. It then details several human diseases where disruption of the nutrition-gut microbiota-immunity axis has been identified and presents examples of how the various elements may be targeted therapeutically as alternate treatment strategies for these diseases.

Maternal Roughage Sources Influence the Gastrointestinal Development of Goat Kids by Modulating the Colonization of Gastrointestinal Microbiota

During pregnancy and lactation, maternal nutrition is linked to the full development of offspring and may have long-term or lifelong effects. However, the influence of the doe's diet on the gastrointestinal (GI) tract of young kids remains largely unexplored. Therefore, we investigated the effects of doe roughage sources (alfalfa hay, AH, or corn straw, CS) during pregnancy and lactation on kid growth, GI morphology, barrier function, metabolism, immunity, and microbiome composition. The results indicate that, compared with the CS group, does fed an AH diet had significantly higher feed intake (p < 0.01). However, CS-fed does exhibited higher neutral detergent fiber (NDF) digestibility (p < 0.05). There were no significant differences in animal (doe or kid) weight among the groups (p > 0.05). In the rumen of goat kids, the AH group exhibited a higher papillae width and increased levels of interleukin-10 (IL-10) compared with the CS group (p < 0.05). In the jejunum of goat kids, the AH group showed a higher villus-height-to-crypt-depth (VH/CD) ratio, as well as elevated levels of secretory immunoglobulin A (SIgA), immunoglobulin G (IgG), IL-10, acetate, and total volatile fatty acids (TVFAs), when compared with the CS group (p < 0.05). Transcriptome analysis revealed that the source of roughage in does was associated with changes in the GI transcriptome of the kids. Differentially expressed genes (DEGs) in the rumen were mainly associated with tissue development and immune regulation, while the DEGs in the jejunum were mainly associated with the regulation of transferase activity. Spearman correlation analyses indicated significant associations between GI DEGs and phenotypic indicators related to GI development, immunity, and metabolism. LEfSe analysis identified 14 rumen microbial biomarkers and 6 jejunum microbial biomarkers. Notably, these microorganisms were also enriched in the rumen or day 28 milk of the does. Further microbial composition analysis revealed significant correlations between the rumen and milk microbiomes of does and the rumen or jejunum microbiomes of kids. Association analyses indicated that microbial biomarkers interact with host genes, thereby affecting the development and function of the GI system. Additionally, correlation analyses revealed significant association between milk metabolites and the rumen and jejunum microbiomes of kids. This study demonstrated that maternal diet significantly influences the development of microbial ecosystems in offspring by modulating microbial communities and metabolite composition. The early colonization of GI microorganisms is crucial for the structural development, barrier function, immune capacity, and microbial metabolic activity of the GI system.

Metabolic profiles of meconium in preeclamptic and normotensive pregnancies

INTRODUCTION

Preeclampsia (PE) is a common vascular pregnancy disorder affecting maternal and fetal metabolism with severe immediate and long-term consequences in mothers and infants. During pregnancy, metabolites in the maternal circulation pass through the placenta to the fetus. Meconium, a first stool of the neonate, offers a view to maternal and fetoplacental unit metabolism and could add to knowledge on the effects of PE on the fetus and newborn.

OBJECTIVES

To compare meconium metabolome of infants from PE and normotensive pregnancies.

METHODS

A cohort of preeclamptic parturients and normotensive controls were recruited in Tampere University Hospital during 2019-2022. Meconium was sampled and its metabolome analyzed using liquid chromatography- mass spectrometry in 48 subjects in each group.

RESULTS

Differences in abundances of 1263 compounds, of which 19 could be annotated, were detected between the two groups. Several acylcarnitines, androsterone sulfate, three bile acids, amino acid derivatives (phenylacetylglutamine, epsilon-(gamma-glutamyl)lysine and N-(phenylacetyl)glutamic acid), as well as caffeine and paraxanthine were lower in the PE group compared to the control group. Urea and progesterone were higher in the PE group.

CONCLUSION

PE is associated with alterations in the meconium metabolome of infants. The differing abundances of several metabolites show alterations in the interaction between the fetoplacental unit and mother in PE, but whether they are a cause or an effect of the disorder remains to be further investigated.

Exploring the composition of placental microbiome and its potential origin in preterm birth

Introduction

For years, the placenta was believed to be sterile, but recent studies reveal it hosts a unique microbiome. Despite these findings, significant questions remain about the origins of the placental microbiome and its effects on pregnancy and fetal health. Some studies suggest it may originate from the vaginal tract, while others indicate that oral bacteria can enter the maternal bloodstream and seed the placenta. However, research analyzing the vaginal, oral, and placental microbiomes within the same cohort is lacking. Additionally, it's unclear whether the placental microbiome differs between healthy pregnancies and those with complications like preterm birth (PTB), which remains a leading cause of neonatal morbidity and mortality worldwide.

Methods

In this study, we performed 16S rRNA gene sequencing to investigate the composition of the oral and placental microbiome in samples collected from 18 women who experienced PTB and 36 matched controls who delivered at term (TB), all of whom were part of the Molecular Signature in Pregnancy (MSP) study. We leveraged on the multisite microbiome sampling from the MSP participants and on our previously published vaginal microbiome data to investigate the potential origins of the placental microbiome and assess whether its composition varies between healthy and complicated pregnancies.

Results and Discussion

Our analysis revealed distinct profiles in the oral microbiome of PTB subjects compared to those who delivered at term. Specifically, we observed an increased abundance of Treponema maltophilum, Bacteroides sp, Mollicutes, Prevotella buccae, Leptotrichia, Prevotella_sp_Alloprevotella, in the PTB group. Importantly, Treponema maltophilum species showed higher abundance in the PTB group during the second trimester, suggesting its potential use as biomarkers. When we assessed the placenta microbiome composition, we found that Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria were the most dominant phyla. Interestingly, microorganisms such as Ureaplasma urealyticum were more abundant in PTB placenta samples. Our findings suggest that the placenta microbiome could originate from the oral or vaginal cavities, with a notable increase in the crosstalk between the vaginal and placental sites in cases of PTB. Specifically, our data revealed that in PTB cases, the placental microbiome exhibited a closer resemblance to the vaginal microbiome, whereas in term pregnancies, the placental microbiome was similar to the oral microbiome.

Clinical implications of maternal multikingdom transmissions and early-life microbiota

Mother-to-infant transmission of the bacteriome, virome, mycobiome, archaeome, and their mobile genetic elements has been recognised in nature as an important step for the infant to acquire and maintain a healthy early-life (from birth till age 3 years) microbiota. A comprehensive overview of other maternal multikingdom transmissions remains unavailable, except for that of the bacteriome. Associations between microorganisms and diseases throughout the human life span have been gradually discovered; however, whether these microorganisms are maternally derived and how they concomitantly interact with other microbial counterparts remain poorly understood. This Review first discusses the current understanding of maternal multikingdom transmissions, their contributions to the development of early-life microbiota, and the primary factors that influence the transmission processes. The clinical implications of the inherited microbiota on human health in early life have been emphasised upon next, along with highlighting of knowledge gaps that should be addressed in future research. Finally, interventions to restore typical vertical transmission or disturbed early-life microbiota have been discussed as potential therapeutic approaches.

Impact of Early-Life Microbiota on Immune System Development and Allergic Disorders

Introduction: The shaping of the human intestinal microbiota starts during the intrauterine period and continues through the subsequent stages of extrauterine life. The microbiota plays a significant role in the predisposition and development of immune diseases, as well as various inflammatory processes. Importantly, the proper colonization of the fetal digestive system is influenced by maternal microbiota, the method of pregnancy completion and the further formation of the microbiota. In the subsequent stages of a child's life, breastfeeding, diet and the use of antibiotics influence the state of eubiosis, which determines proper growth and development from the neonatal period to adulthood. The literature data suggest that there is evidence to confirm that the intestinal microbiota of the infant plays an important role in regulating the immune response associated with the development of allergic diseases. However, the identification of specific bacterial species in relation to specific types of reactions in allergic diseases is the basic problem. Background: The main aim of the review was to demonstrate the influence of the microbiota of the mother, fetus and newborn on the functioning of the immune system in the context of allergies and asthma. Methods: We reviewed and thoroughly analyzed the content of over 1000 articles and abstracts between the beginning of June and the end of August 2024. Over 150 articles were selected for the detailed study. Results: The selection was based on the PubMed National Library of Medicine search engine, using selected keywords: "the impact of intestinal microbiota on the development of immune diseases and asthma", "intestinal microbiota and allergic diseases", "the impact of intrauterine microbiota on the development of asthma", "intrauterine microbiota and immune diseases", "intrauterine microbiota and atopic dermatitis", "intrauterine microbiota and food allergies", "maternal microbiota", "fetal microbiota" and "neonatal microbiota". The above relationships constituted the main criteria for including articles in the analysis. Conclusions: In the present review, we showed a relationship between the proper maternal microbiota and the normal functioning of the fetal and neonatal immune system. The state of eubiosis with an adequate amount and diversity of microbiota is essential in preventing the development of immune and allergic diseases. The way the microbiota is shaped, resulting from the health-promoting behavior of pregnant women, the rational conduct of the medical staff and the proper performance of the diagnostic and therapeutic process, is necessary to maintain the health of the mother and the child. Therefore, an appropriate lifestyle, rational antibiotic therapy as well as the way of completing the pregnancy are indispensable in the prevention of the above conditions. At the same time, considering the intestinal microbiota of the newborn in relation to the genera and phyla of bacteria that have a potentially protective effect, it is worth noting that the use of suitable probiotics and prebiotics seems to contribute to the protective effect.

Innate immune cells link dietary cues to normal and abnormal metabolic regulation

A slew of common metabolic disorders, including type 2 diabetes, metabolic dysfunction-associated steatotic liver disease and steatohepatitis, are exponentially increasing in our sedentary and overfed society. While macronutrients directly impact metabolism and bioenergetics, new evidence implicates immune cells as critical sensors of nutritional cues and important regulators of metabolic homeostasis. A deeper interrogation of the intricate and multipartite interactions between dietary components, immune cells and metabolically active tissues is needed for a better understanding of metabolic regulation and development of new treatments for common metabolic diseases. Responding to macronutrients and micronutrients, immune cells play pivotal roles in interorgan communication between the microbiota, small intestine, metabolically active cells including hepatocytes and adipocytes, and the brain, which controls feeding behavior and energy expenditure. This Review focuses on the response of myeloid cells and innate lymphocytes to dietary cues, their cross-regulatory interactions and roles in normal and aberrant metabolic control.

Microbiome and Hemato-immune Aging

The microbiome is a highly complex and diverse symbiotic component that undergoes dynamic changes with the organismal aging. Microbial perturbations, termed dysbiosis, exert strong influence on dysregulating the bone marrow niche and subsequently promoting the aging of hematopoietic and immune system. Accumulating studies have revealed the substantial impact of intestinal microbiome on the initiation and progression of age-related hematologic alteration and diseases, such as clonal hematopoiesis and blood cancers. Current therapeutic approaches to restore the altered microbiome diversity target specific pathobionts and are demonstrated to improve clinical outcomes of antihematologic malignancy treatments. In this review, we discuss the interplay between the microbiome and the hemato-immune system during aging process. We also shed light on the emerging therapeutic strategies to tackle the dysbiosis for amelioration of aging and disease progression.

Cataloguing the postnatal small intestinal transcriptome during the first postnatal month

In the first postnatal month, the developing mouse intestine shifts from an immature to a mature intestine that will sustain the organism throughout the lifespan. Here, we surveyed the mouse intestine in C57Bl/6 mice by RNA-Seq to evaluate the changes in gene expression over time from the day of birth through 1 month of age in both the duodenum and ileum. We analyzed gene expression for changes in gene families that correlated with the periods of NEC susceptibility or resistance. We highlight that increased expression of DNA processing genes and vacuolar structure genes, tissue development and morphogenesis genes, and cell migration genes all correlated with NEC susceptibility, while increases in immunity gene sets, intracellular transport genes, ATP production, and intracellular metabolism genes correlated with NEC resistance. Using trends identified in the RNA-Seq analyses, we further evaluated expression of cellular markers and epithelial regulators, immune cell markers, and adenosine metabolism components. We confirmed key changes with qRT-PCR and immunofluorescence. In addition, we compared some findings to humans using human intestinal biopsies and organoids. This dataset can serve as a reference for other groups considering the role of single molecules or molecular families in early intestinal and postnatal development.

Therapeutic Potential of Nutritional Aryl Hydrocarbon Receptor Ligands in Gut-Related Inflammation and Diseases

A solid scientific foundation is required to build the concept of personalized nutrition developed to promote health and a vision of disease prevention. Growing evidence indicates that nutrition can modulate the immune system through metabolites, which are either generated via microbiota metabolism or host digestion. The aryl hydrocarbon receptor (AhR) plays a crucial role in regulating immune responses, particularly in the gut, and has emerged as a key modulator of gut-mediated inflammation and related diseases. AhR is a ligand-activated transcription factor that responds to environmental, dietary, and microbial-derived signals, influencing immune balance and maintaining intestinal homeostasis. Nutritional AhR ligands play a significant role in modulating intestinal immunity and the function of mucosal immune cells, thereby exerting clinical effects on colitis and innate immunity. Additionally, they have the capacity to orchestrate autophagy, phagocytic cell function, and intestinal epithelial tight junctions. Therapeutic strategies aimed at enhancing AhR activity, restoring gut integrity, and optimizing immune responses hold promise as avenues for future research and potential treatments for critically ill patients.

Prenatal antibiotics reduce breast milk IgA and induce dysbiosis in mouse offspring, increasing neonatal susceptibility to bacterial sepsis

Antibiotics (Abx) are administered to 20%-30% of pregnant women, but their effects on neonatal immune development are poorly understood. We show that newborn mice born to Abx-treated dams are more susceptible to late-onset sepsis. This susceptibility is linked to lower maternal breast milk immunoglobulin A (IgA), neonatal fecal IgA, and IgA coating of intestinal bacteria, thus causing the translocation of intestinal pathobionts. Weaned young adults born to Abx-treated mothers had reduced IgA+ plasma cells in the ileum and colon, fecal secretory IgA (SIgA), colonic CD4+ T regulatory lymphocytes and T helper 17-like lymphocytes, and a less diverse fecal microbiome. However, treatment with apyrase, which restores SIgA secretion, prompted IgA production in breast milk and protected pups from sepsis. Additionally, breast milk from untreated mothers rescued the phenotypes of pups born to Abx-treated mothers. Our data highlight the impact of prenatal Abx on breast milk IgA and their long-term influence on intestinal mucosal immune function mediated by breastfeeding.