The microbiome in early life: implications for health outcomes

Gut microbiota-metabolite interactions meditate the effect of dietary patterns on precocious puberty

Precocious puberty, a pediatric endocrine disorder classified as central precocious puberty (CPP) or peripheral precocious puberty (PPP), is influenced by diet, gut microbiota, and metabolites, but the specific mechanisms remain unclear. Our study found that increased alpha-diversity and abundance of short-chain fatty acid-producing bacteria led to elevated levels of luteinizing hormone and follicle-stimulating hormone, contributing to precocious puberty. The integration of specific microbiota and metabolites has potential diagnostic value for precocious puberty. The Prevotella genus-controlled interaction factor, influenced by complex carbohydrate consumption, mediated a reduction in estradiol levels. Interactions between obesity-related bacteria and metabolites mediated the beneficial effect of seafood in reducing luteinizing hormone levels, reducing the risk of obesity-induced precocious puberty, and preventing progression from PPP to CPP. This study provides valuable insights into the complex interplay between diet, gut microbiota and metabolites in the onset, development and clinical classification of precocious puberty and warrants further investigation.

Postdiscontinuation Antibiotic Exposure in Hospitalized Infants at Risk for Late-onset Sepsis in the Neonatal Intensive Care Unit

BACKGROUND

In the neonatal intensive care unit, infants are at risk for late-onset sepsis. When blood cultures are negative, antibiotic stewardship efforts encourage stopping antibiotics, yet the duration of therapeutic exposure after the last dose is unknown.

METHODS

This retrospective cohort study of simulated antibiotic exposures used published population pharmacokinetic models within drug-specific neonatal intensive care unit cohorts of preterm and term infants, postnatal age 7-60 days and exposed to cefepime, piperacillin-tazobactam or tobramycin. Monte Carlo simulations (NONMEM 7.3) were used to predict steady-state exposures after a 72-hour antibiotic course per Neofax dosing. Exposure was assessed relative to drug-specific minimum inhibitory concentration (MIC) targets between 1 and 16 mcg/mL for Pseudomonas and Enterobacteriaceae species. Postdiscontinuation antibiotic exposure (PDAE) was defined as the time from the last dose to when antibiotic concentration decreased below a specific MIC.

RESULTS

Piperacillin-tazobactam, cefepime and tobramycin cohorts included infants with median gestation age 29, 32 and 32 weeks and postnatal age 17, 19 and 15 days, respectively. The mean PDAE was 19-68 hours, depending on the specific antibiotic/MIC combination. PDAE was longer for infants <28 days old and preterm (vs. term) infants. Cefepime exhibited the longest mean PDAE of 68 hours for Enterobacteriaceae MIC 1. Piperacillin mean PDAE was 25 hours for Enterobacteriaceae MIC 8. Tobramycin had a short mean PDAE of 19 hours.

CONCLUSIONS

Piperacillin and cefepime exposures remained therapeutic long after the expected 8- to 12-hour dosing interval. PDAE is an important consideration for antibiotic stewardship among hospitalized infants, particularly premature infants and those within 1 month postbirth.

A synbiotic of Anaerostipes caccae and lactulose prevents and treats food allergy in mice

Depletion of beneficial microbes by modern lifestyle factors correlates with the rising prevalence of food allergies. Re-introduction of allergy-protective bacteria may be an effective treatment strategy. We characterized the fecal microbiota of healthy and food-allergic infants and found that the anaerobe Anaerostipes caccae (A. caccae) was representative of the protective capacity of the healthy microbiota. We isolated a strain of A. caccae from the feces of a healthy infant and identified lactulose as a prebiotic to optimize butyrate production by A. caccae in vitro. Administration of a synbiotic composed of our isolated A. caccae strain and lactulose increased luminal butyrate in gnotobiotic mice colonized with feces from an allergic infant and in antibiotic-treated specific pathogen-free (SPF) mice, and prevented or treated an anaphylactic response to allergen challenge. The synbiotic's efficacy in two models and microbial contexts suggests that it may be a promising approach for the treatment of food allergy.

Perturbed maternal microbiota shapes offspring microbiota during early colonization period in mice

Recent studies have highlighted the impact of disrupted maternal gut microbiota on the colonization of offspring gut microbiota, with implications for offspring developmental trajectories. The extent to which offspring inherit the characteristics of altered maternal gut microbiota remains elusive. In this study, we employed a mouse model where maternal gut microbiota disruption was induced using non-absorbable antibiotics. Systematic chronological analyses of dam fecal samples, offspring luminal content, and offspring gut tissue samples revealed a notable congruence between offspring gut microbiota profiles and those of the perturbed maternal gut microbiota, highlighting the profound influence of maternal microbiota on early-life colonization of offspring gut microbiota. Nonetheless, certain dominant bacterial genera in maternal microbiota did not transfer to the offspring, indicating a bacterial taxonomy-dependent mechanism in the inheritance of maternal gut microbiota. Our results embody the vertical transmission dynamics of disrupted maternal gut microbiota in an animal model, where the gut microbiota of an offspring closely mirrors the gut microbiota of its mother.

The role of antibiotic exposure and the effects of breastmilk and human milk feeding on the developing infant gut microbiome

The World Health Organization (WHO) recommends exclusive breastfeeding for the first 6 months of life followed by complementary foods and sustained breastfeeding for at least 2 years, underscoring its pivotal role in reducing infant mortality and preventing various illnesses. This perspective delves into the intricate relationship between breastfeeding practices, early life antibiotic exposure, and infant gut microbiome development, highlighting their profound influence on child health outcomes. Antibiotics are extensively prescribed during pregnancy and childhood, disrupting the microbiome, and are related to increased risks of allergies, obesity, and neurodevelopmental disorders. Breastfeeding is a significant determinant of a healthier gut microbiome, characterized by higher levels of beneficial bacteria such as Bifidobacterium and lower levels of potential pathogens. Despite widespread recognition of the benefits of breastfeeding, gaps persist in healthcare practices and support mechanisms, exacerbating challenges faced by breastfeeding families. This highlights the pressing need for comprehensive research encompassing breastfeeding behaviors, human milk intake, and their impact on infant health outcomes. Additionally, promoting awareness among healthcare providers and families regarding the detrimental effects of unnecessary formula supplementation could facilitate informed decision-making and bolster exclusive breastfeeding rates. Moreover, donor human milk (DHM) is a promising alternative to formula, potentially mitigating disruptions to the infant gut microbiome after antibiotic exposure. Overall, prioritizing breastfeeding support interventions and bridging research gaps are essential steps towards improving child health outcomes on a global scale.

Lung microbiome: new insights into bronchiectasis' outcome

The present treatments for bronchiectasis, which is defined by pathological dilatation of the airways, are confined to symptom relief and minimizing exacerbations. The condition is becoming more common worldwide. Since the disease's pathophysiology is not entirely well understood, developing novel treatments is critically important. The interplay of chronic infection, inflammation, and compromised mucociliary clearance, which results in structural alterations and the emergence of new infection, is most likely responsible for the progression of bronchiectasis. Other than treating bronchiectasis caused by cystic fibrosis, there are no approved treatments. Understanding the involvement of the microbiome in this disease is crucial, the microbiome is defined as the collective genetic material of all bacteria in an environment. In clinical practice, bacteria in the lungs have been studied using cultures; however, in recent years, researchers use next-generation sequencing methods, such as 16S rRNA sequencing. Although the microbiome in bronchiectasis has not been entirely investigated, what is known about it suggests that Haemophilus, Pseudomonas and Streptococcus dominate the lung bacterial ecosystems, they present significant intraindividual stability and interindividual heterogeneity. Pseudomonas and Haemophilus-dominated microbiomes have been linked to more severe diseases and frequent exacerbations, however additional research is required to fully comprehend the role of microbiome in the evolution of bronchiectasis. This review discusses recent findings on the lung microbiota and its association with bronchiectasis.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: the biology of a neglected disease

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, debilitating disease characterised by a wide range of symptoms that severely impact all aspects of life. Despite its significant prevalence, ME/CFS remains one of the most understudied and misunderstood conditions in modern medicine. ME/CFS lacks standardised diagnostic criteria owing to variations in both inclusion and exclusion criteria across different diagnostic guidelines, and furthermore, there are currently no effective treatments available. Moving beyond the traditional fragmented perspectives that have limited our understanding and management of the disease, our analysis of current information on ME/CFS represents a significant paradigm shift by synthesising the disease's multifactorial origins into a cohesive model. We discuss how ME/CFS emerges from an intricate web of genetic vulnerabilities and environmental triggers, notably viral infections, leading to a complex series of pathological responses including immune dysregulation, chronic inflammation, gut dysbiosis, and metabolic disturbances. This comprehensive model not only advances our understanding of ME/CFS's pathophysiology but also opens new avenues for research and potential therapeutic strategies. By integrating these disparate elements, our work emphasises the necessity of a holistic approach to diagnosing, researching, and treating ME/CFS, urging the scientific community to reconsider the disease's complexity and the multifaceted approach required for its study and management.

Health by design; optimising our urban environmental microbiomes for human health

Humans have evolved in direct and intimate contact with their environment and the microbes that it contains, over a period of 2 million years. As a result, human physiology has become intrinsically linked to environmental microbiota. Urbanisation has reduced our exposure to harmful pathogens, however there is now increasing evidence that these same health-protective improvements in our environment may also be contributing to a hidden disease burden: immune dysregulation. Thoughtful and purposeful design has the potential to ameliorate these health concerns by providing sources of microbial diversity for human exposure. In this narrative review, we highlight the role of environmental microbiota in human health and provide insights into how we can optimise human health through well-designed cities, urban landscapes and buildings. The World Health Organization recommends there should be at least one public green space of least 0.5 ha in size within 300m of a place of residence. We argue that these larger green spaces are more likely to permit functioning ecosystems that deliver ecosystem services, including the provision of diverse aerobiomes. Urban planning must consider the conservation and addition of large public green spaces, while landscape design needs to consider how to maximise environmental, social and public health outcomes, which may include rewilding. Landscape designers need to consider how people use these spaces, and how to optimise utilisation, including for those who may experience challenges in access (e.g. those living with disabilities, people in residential care). There are also opportunities to improve health via building design that improves access to diverse environmental microbiota. Considerations include having windows that open, indoor plants, and the relationship between function, form and organization. We emphasise possibilities for re-introducing potentially health-giving microbial exposures into urban environments, particularly where the benefits of exposure to biodiverse environments may have been lost.

Early life microbiome influences on development of the mucosal innate immune system

The gut microbiota is well known to possess immunomodulatory capacities, influencing a multitude of cellular signalling pathways to maintain host homeostasis. Although the formation of the immune system initiates before birth in a sterile environment, an emerging body of literature indicates that the neonatal immune system is influenced by a first wave of external stimuli that includes signals from the maternal microbiota. A second wave of stimulus begins after birth and must be tightly regulated during the neonatal period when colonization of the host occurs concomitantly with the maturation of the immune system, requiring a fine adjustment between establishing tolerance towards the commensal microbiota and preserving inflammatory responses against pathogenic invaders. Besides integrating cues from commensal microbes, the neonatal immune system must also regulate responses triggered by other environmental signals, such as dietary antigens, which become more complex with the introduction of solid food during the weaning period. This "window of opportunity" in early life is thought to be crucial for the proper development of the immune system, setting the tone of subsequent immune responses in adulthood and modulating the risk of developing chronic and metabolic inflammatory diseases. Here we review the importance of host-microbiota interactions for the development and maturation of the immune system, particularly in the early-life period, highlighting the known mechanisms involved in such communication. This discussion is focused on recent data demonstrating microbiota-mediated education of innate immune cells and its role in the development of lymphoid tissues.

Nurturing development: how a mother's nutrition shapes offspring's brain through the gut

Pregnancy is a transformative period marked by profound physical and emotional changes, with far-reaching consequences for both mother and child. Emerging research has illustrated the pivotal role of a mother's diet during pregnancy in influencing the prenatal gut microbiome and subsequently shaping the neurodevelopment of her offspring. The intricate interplay between maternal gut health, nutrition, and neurodevelopmental outcomes has emerged as a captivating field of investigation within developmental science. Acting as a dynamic bridge between mother and fetus, the maternal gut microbiome, directly and indirectly, impacts the offspring's neurodevelopment through diverse pathways. This comprehensive review delves into a spectrum of studies, clarifying putative mechanisms through which maternal nutrition, by modulating the gut microbiota, orchestrates the early stages of brain development. Drawing insights from animal models and human cohorts, this work underscores the profound implications of maternal gut health for neurodevelopmental trajectories and offers a glimpse into the formulation of targeted interventions able to optimize the health of both mother and offspring. The prospect of tailored dietary recommendations for expectant mothers emerges as a promising and accessible intervention to foster the growth of beneficial gut bacteria, potentially leading to enhanced cognitive outcomes and reduced risks of neurodevelopmental disorders.

Probiotics in the New Era of Human Milk Oligosaccharides (HMOs): HMO Utilization and Beneficial Effects of Bifidobacterium longum subsp. infantis M-63 on Infant Health

A healthy gut microbiome is crucial for the immune system and overall development of infants. Bifidobacterium has been known to be a predominant species in the infant gut; however, an emerging concern is the apparent loss of this genus, in particular, Bifidobacterium longum subsp. infantis (B. infantis) in the gut microbiome of infants in industrialized nations, underscoring the importance of restoring this beneficial bacterium. With the growing understanding of the gut microbiome, probiotics, especially infant-type human-residential bifidobacteria (HRB) strains like B. infantis, are gaining prominence for their unique ability to utilize HMOs and positively influence infant health. This article delves into the physiology of a probiotic strain, B. infantis M-63, its symbiotic relationship with HMOs, and its potential in improving gastrointestinal and allergic conditions in infants and children. Moreover, this article critically assesses the role of HMOs and the emerging trend of supplementing infant formulas with the prebiotic HMOs, which serve as fuel for beneficial gut bacteria, thereby emulating the protective effects of breastfeeding. The review highlights the potential of combining B. infantis M-63 with HMOs as a feasible strategy to improve health outcomes in infants and children, acknowledging the complexities and requirements for further research in this area.

Antibiotic use in early life subsequently impairs MAIT cell-mediated immunity

Mucosal-associated invariant T (MAIT) cells are predominantly located in barrier tissues where they rapidly respond to pathogens and commensals by recognizing microbial derivatives of riboflavin synthesis. Early-life exposure to these metabolites imprints the abundance of MAIT cells within tissues, so we hypothesized that antibiotic use during this period may abrogate their development. We identified antibiotics that deplete riboflavin-synthesizing commensals and revealed an early period of susceptibility during which antibiotic administration impaired MAIT cell development. The reduction in MAIT cell abundance rendered mice more susceptible to pneumonia, while MAIT cell-deficient mice were unaffected by early-life antibiotics. Concomitant administration of a riboflavin-synthesizing commensal during antibiotic treatment was sufficient to restore MAIT cell development and immunity. Our work demonstrates that transient depletion of riboflavin-synthesizing commensals in early life can adversely affect responses to subsequent infections.

Fecal microbiota profiles of growing pigs and their relation to growth performance

The early gut microbiota composition is fundamentally important for piglet health, affecting long-term microbiome development and immunity. In this study, the gut microbiota of postparturient dams was compared with that of their offspring in three Finnish pig farms at three growth phases. The differences in fecal microbiota of three study development groups (Good, Poorly, and PrematureDeath) were analyzed at birth (initial exposure phase), weaning (transitional phase), and before slaughter (stable phase). Dam Lactobacillaceae abundance was lower than in piglets at birth. Limosilactobacillus reuteri and Lactobacillus amylovorus were dominantly expressed in dams and their offspring. Altogether 17 piglets (68%) were identified with Lactobacillaceae at the initial exposure phase, divided unevenly among the development groups: 85% of Good, 37.5% of Poorly, and 75% of PrematureDeath pigs. The development group Good was identified with the highest microbial diversity, whereas the development group PrematureDeath had the lowest diversity. After weaning, the abundance and versatility of Lactobacillaceae in piglets diminished, shifting towards the microbiome of the dam. In conclusion, the fecal microbiota of pigs tends to develop towards a similar alpha and beta diversity despite development group and rearing environment.

Prenatal PFAS exposure, gut microbiota dysbiosis, and neurobehavioral development in childhood

Studies on the role of the gut microbiota in the associations between per- and polyfluoroalkyl substance (PFAS) exposure and adverse neurodevelopment are limited. Umbilical cord serum and faeces samples were collected from children, and the Strengths and Difficulties Questionnaire (SDQ) was conducted. Generalized linear models, linear mixed-effects models, multivariate analysis by linear models and microbiome regression-based kernel association tests were used to evaluate the associations among PFAS exposure, the gut microbiota, and neurobehavioural development. Perfluorohexane sulfonic acid (PFHxS) exposure was associated with increased scores for conduct problems and externalizing problems, as well as altered gut microbiota alpha and beta diversity. PFHxS concentrations were associated with higher relative abundances of Enterococcus spp. but lower relative abundances of several short-chain fatty acid-producing genera (e.g., Ruminococcus gauvreauii group spp.). PFHxS exposure was also associated with increased oxidative phosphorylation. Alpha and beta diversity were found significantly associated with conduct problems and externalizing problems. Ruminococcus gauvreauii group spp. abundance was positively correlated with prosocial behavior scores. Increased alpha diversity played a mediating role in the associations of PFHxS exposure with conduct problems. Our results suggest that the gut microbiota might play an important role in PFAS neurotoxicity, which may have implications for PFAS control.

Impact of Transgenerational Nutrition on Nonalcoholic Fatty Liver Disease Development: Interplay between Gut Microbiota, Epigenetics and Immunity

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most prevalent pediatric liver disorder, primarily attributed to dietary shifts in recent years. NAFLD is characterized by the accumulation of lipid species in hepatocytes, leading to liver inflammation that can progress to steatohepatitis, fibrosis, and cirrhosis. Risk factors contributing to NAFLD encompass genetic variations and metabolic disorders such as obesity, diabetes, and insulin resistance. Moreover, transgenerational influences, resulting in an imbalance of gut microbial composition, epigenetic modifications, and dysregulated hepatic immune responses in offspring, play a pivotal role in pediatric NAFLD development. Maternal nutrition shapes the profile of microbiota-derived metabolites in offspring, exerting significant influence on immune system regulation and the development of metabolic syndrome in offspring. In this review, we summarize recent evidence elucidating the intricate interplay between gut microbiota, epigenetics, and immunity in fetuses exposed to maternal nutrition, and its impact on the onset of NAFLD in offspring. Furthermore, potential therapeutic strategies targeting this network are also discussed.

Interleukin-1 family cytokines at the crossroads of microbiome regulation in barrier health and disease

Recent advances in understanding how the microbiome can influence both the physiology and the pathogenesis of disease in humans have highlighted the importance of gaining a deeper insight into the complexities of the host-microbial dialogue. In tandem with this progress, has been a greater understanding of the biological pathways which regulate both homeostasis and inflammation at barrier tissue sites, such as the skin and the gut. In this regard, the Interleukin-1 family of cytokines, which can be segregated into IL-1, IL-18 and IL-36 subfamilies, have emerged as important custodians of barrier health and immunity. With established roles as orchestrators of various inflammatory diseases in both the skin and intestine, it is now becoming clear that IL-1 family cytokine activity is not only directly influenced by external microbes, but can also play important roles in shaping the composition of the microbiome at barrier sites. This review explores the current knowledge surrounding the evidence that places these cytokines as key mediators at the interface between the microbiome and human health and disease at the skin and intestinal barrier tissues.

Bifidobacterium Against COVID-19: A Mother and Her Newborn's Gut Microbiome

Several treatments and preventive measures for SARS-CoV-2 were studied during the pandemic, but few focused on the neonatal gut microbiome and its role in the setting of COVID-19. This case report is unique because it describes the gut microbiomes of a mother and her newborn, who both contracted COVID-19 shortly after the baby's birth. In this prospective study, on day 11 postpartum, both the newborn and mother (38 years old), of white race/ethnicity, were exposed to a COVID-19-positive person. After exposure, the mother received a 40,000 IU bolus of vitamin D orally and started a five-day course of high-dose vitamin C (10,000 mg daily), after which she continued her daily combination of vitamins C, D, and zinc pill with probiotic skyr yogurt and manuka honey. Stool specimens and DNA were extracted, quantitated, and normalized from the mother and the newborn for downstream library fabrication utilizing shotgun methodology. Baseline Bifidobacteria level for the mother was 1.5% which increased to 19% on day 15 postpartum after testing positive for COVID-19 and taking vitamin C. Neonatal Bifidobacteriasteadily increased regardless of COVID-19 infection. We propose that the disease course was altered by maternal supplementation of vitamins C and D and zinc, which may have increased Bifidobacterium levels and led to improved outcomes for both patients.

Gestational supplementation of Bifidobacterium, Lactobacillus, and Streptococcus thermophilus attenuates hepatic steatosis in offspring mice through promoting fatty acid β-oxidation

Currently, Bifidobacterium, Lactobacillus, and Streptococcus thermophilus (BLS) are widely recognized as the crucially beneficial bacteria in the gut. Many preclinical and clinical studies have shown their protective effects against non-alcoholic fatty liver disease (NAFLD). However, whether gestational BLS supplementation could alleviate NAFLD in the offspring is still unknown. Kunming mice were given a high-fat diet (HFD) for 4 weeks before mating. They received BLS supplementation by gavage during pregnancy. After weaning, offspring mice were fed with a regular diet up to 5 weeks old. Gestational BLS supplementation significantly increased the abundance of Actinobacteriota, Bifidobacterium, and Faecalibaculum in the gut of dams exposed to HFD. In offspring mice exposed to maternal HFD, maternal BLS intake significantly decreased the ratio of Firmicutes to Bacteroidetes as well as the relative abundance of Prevotella and Streptococcus, but increased the relative abundance of Parabacteroides. In offspring mice, maternal BLS supplementation significantly decreased the hepatic triglyceride content and mitigated hepatic steatosis. Furthermore, maternal BLS supplementation increased the glutathione content and reduced malondialdehyde content in the liver. In addition, mRNA and protein expression levels of key rate-limiting enzymes in mitochondrial β-oxidation (CPT1α, PPARα, and PGC1α) in the livers of offspring mice were significantly increased after gestational BLS supplementation. Thus, gestational BLS supplementation may ameliorate maternal HFD-induced steatosis and oxidative stress in the livers of offspring mice by modulating fatty acid β-oxidation.

High-fat diet during early life reshapes the gut microbiome and is associated with the disrupted mammary microenvironment in later life in mice

The influence of gut microbiota on gut health is well-documented, but it remains obscure for extraintestinal diseases such as breast cancer. Moreover, it is entirely unknown how gut dysbiosis during early life contributes to breast tumorigenesis later in life. In this study, we hypothesized that a high-fat diet during early life leads to alterations in the gut microbiome and is associated with disruptions in the mammary microenvironment. Female C57BL/6 mice were fed a low-fat diet (10% kcal fat) or a high-fat diet (HF, 60% kcal fat) for 8 weeks from the age of 4 to 12 weeks, which is equivalent to human childhood and adolescence. Twelve mice were sacrificed immediately after the 8-week feeding, the remainder were euthanized after switching to a normal lifecycle-supporting diet for an additional 12 weeks; the gut microbiome was then sequenced. The 8-week HF diet feeding altered the beta-diversity (Bray & Jaccard P < .01), and the difference remained significant after switching the diet (Bray & Jaccard P < .05). Immediately after HF feeding, a greater number of microbial taxa (>50) were altered, and about half of the taxa (25) remained significantly changed after switching the diet. The abundance of Alistipes, Bilophila, and Rikenellaceae stood out as significantly associated with multiple metabolic and inflammatory biomarkers in mammary tissue, including aromatase, Ccl2, and Cox2. In conclusion, an 8-week early-life HF feeding reshaped the gut microbiome, which connected with disrupted mammary microenvironments.

The link between obesity and the gut microbiota and immune system in early-life

In early-life, the gut microbiota is highly modifiable, being modulated by external factors such as maternal microbiota, mode of delivery, and feeding strategies. The composition of the child's gut microbiota will deeply impact the development and maturation of its immune system, with consequences for future health. As one of the main sources of microorganisms to the child, the mother represents a crucial factor in the establishment of early-life microbiota, impacting the infant's wellbeing. Recent studies have proposed that dysbiotic maternal gut microbiota could be transmitted to the offspring, influencing the development of its immunity, and leading to the development of diseases such as obesity. This paper aims to review recent findings in gut microbiota and immune system interaction in early-life, highlighting the benefits of a balanced gut microbiota in the regulation of the immune system.

Dupilumab therapy improves gut microbiome dysbiosis and tryptophan metabolism in Chinese patients with atopic dermatitis

BACKGROUND

Dupilumab has demonstrate its potential to orchestrate inflammatory skin microenvironment, enhance skin barrier and shift skin microbiome dysbiosis, collectively contributing to clinical improvement in patients with atopic dermatitis (AD). As the second genome of human body, growing evidence suggests that the gut microbiome might relate to the host response to treatments. Little is known about the association between dupilumab treatment and gut microbiome in AD patients.

OBJECTIVE

We aimed to characterize the gut microbiome among Chinese subjects with or without AD and determine the potential effect of dupilumab on the gut microbiome.

RESULTS

The 16 s rRNA gene sequencing was conducted on 48 healthy controls (HC), 44 AD patients and 27 AD patients who received dupilumab for 16 weeks. Prior to treatment, we identified the changed beta-diversity, increased Firmicutes/Bacteroidetes ratio, decreased Bifidobacterium and expanded Faecalibacterium among the AD patients compared to HC. After 16 weeks of dupilumab treatment, gut microbiome dysbiosis of the AD patients improved with reversed beta-diversity, closer bacterial connections, increased colonization of Bifidobacterium, Ruminococcus gnavus, and Coprococcus, which were negatively correlated with disease severity indicators. This shift was largely independent of the degree of clinical improvement. Bacterial function analysis revealed further metabolic alterations following dupilumab treatment, including up-regulated expression of genes involved in the indole pathway of tryptophan metabolism, corroborated by quantitative UHPLC-MS/MS analysis.

CONCLUSION

Dupilumab treatment tends to help shift the gut microbial dysbiosis in AD patients to a healthier state, along with improved intestinal tryptophan metabolism, suggesting the gut flora and its metabolites may mediate part of the synergistic therapeutic effects on the host.

Maternal One-Carbon Nutrient Intake and Risk of Being Overweight or Obese in Their Offspring-A Transgenerational Prospective Cohort Study

We aimed to investigate the associations between maternal intake of folate, vitamin B12, B6, B2, methionine, choline, phosphatidylcholine and betaine during the period surrounding pregnancy and offspring weight outcomes from birth to early adulthood. These associations were examined among 2454 mother-child pairs from the Nurses' Health Study II and Growing Up Today Study. Maternal energy-adjusted nutrient intakes were derived from food frequency questionnaires. Birth weight, body size at age 5 and repeated BMI measurements were considered. Overweight/obesity was defined according to the International Obesity Task Force (<18 years) and World Health Organization guidelines (18+ years). Among other estimands, we report relative risks (RRs) for offspring ever being overweight with corresponding 95% confidence intervals across quintiles of dietary factors, with the lowest quintile as the reference. In multivariate-adjusted models, higher maternal intakes of phosphatidylcholine were associated with a higher risk of offspring ever being overweight (RRQ5vsQ1 = 1.16 [1.01-1.33] p-trend: 0.003). The association was stronger among offspring born to mothers with high red meat intake (high red meat RRQ5vsQ1 = 1.50 [1.14-1.98], p-trend: 0.001; low red meat RRQ5vsQ1 = 1.05 [0.87-1.27], p-trend: 0.46; p-interaction = 0.13). Future studies confirming the association between a higher maternal phosphatidylcholine intake during pregnancy and offspring risk of being overweight or obese are needed.

GOSpel for tiny allies

Infant formulas are often supplemented to foster the development of a healthy gut microbiota. In this issue of Cell Host & Microbe, Heppner et al. present an elaborate clinical trial examining the impact of formula supplementation on the development and circadian rhythmicity of the microbiota during the first year of life.

Gut microbiota of one-and-a-half-year-old food-allergic and healthy children

BACKGROUND

Intestinal bacteria may play a role in the development of food allergies. This study aimed to analyze and compare the gut microbiota of food-allergic children with that of healthy children of the same age.

METHODS

Stool samples were collected from one-and-a-half-year-old food-allergic (FA group, n = 29) and healthy controls (HC group, n = 19). A questionnaire was provided to examine the children's birth, dietary, medical, and social histories. The gut microbiota was profiled by 16S rRNA sequencing. Differences in taxonomic composition were assessed using linear discriminant analysis effect size (LEfSe), and microbial functional profiles were predicted with Tax4Fun2.

RESULTS

No significant difference in the alpha diversity index between the two groups; however, a negative correlation was observed between the Shannon diversity index and the relative abundance of Bacteroides. A significant difference was observed in beta diversity (permutational multivariate analysis of variance) in the bacterial composition between the FA and HC groups (P < 0.05). The FA group had a higher abundance of Escherichia and Anaeromassilibacillus and a lower abundance of Bacteroides, Oscillibacter, Ruminococcus, Hungateiclostridium and Anaerotaenia than the HC group (LEfSe: linear discriminant analysis score >2). The FA group showed a predicted increase in the expression levels of genes associated with intestinal pathogenicity compared with that in the HC group.

CONCLUSIONS

The gut microbiota of food-allergic children has a higher abundance of bacteria involved in intestinal inflammation and a lower abundance of bacteria involved in immune tolerance than that of healthy children. This dysbiosis may also be associated with food allergies.

Graduate Student Literature Review: Developmental adaptations of immune function in calves and the influence of the intestinal microbiota in health and disease

This graduate student literature review provides an examination of the ontological adaptations of the calf's immune system and how the intestinal microbiota influences calf immune function in health and disease. Within dairy rearing systems, various nutritional and management factors have emerged as critical determinants of development influencing multiple physiological axes in the calf. Furthermore, we discuss how multiple pre- and postnatal maternal factors influence the trajectory of immune development in favor of establishing regulatory networks to successfully cope with the new environment, while providing early immune protection via immune passive transfer from colostrum. Additionally, our review provides insights into the current understanding of how the intestinal microbiota contributes to the development of the intestinal and systemic immune system in calves. Lastly, we address potential concerns related to the use of prophylactic antimicrobials and waste milk, specifically examining their adverse effects on intestinal health and metabolic function. By examining these factors, we aim to better understand the intricate relationship between current management practices and their long-term effect on animal health.

Effects of oropharyngeal administration of own mother's milk on oral microbial colonization in very low birth weight infants fed by gastric tube: A randomized controlled trial

AIMS

The aim of the present study was to explore the effect of oropharyngeal mother's milk administration on oral microbial colonization in infants fed by gastric tube at different time points.

METHODS

Infants (n = 116) with birth weight <1500 g were randomly allocated into two groups which both received breast milk for enteral nutrition. The control group (n = 51) accepted oropharyngeal normal saline administration. The experimental group (n = 53) accepted oropharyngeal mother's milk administration before fed by gastric tube once every 3 h over 21 days after birth. We analyzed the oral microbiota at initiation and 7 and 14 and 21 days later using 16S DNA amplicon sequencing.

RESULTS

There were no difference in oral microbial diversity between the two groups at any time point, but diversity decreased significantly over time in both groups. On the first day of life, the oral microbiota of the infant in the experimental and control groups consisted mainly of Firmicutes (7.75%, 6.18%) and Proteobacteria (68.65%, 68.69%), respectively. As time increases to 21 days after birth, Firmicutes (77.67%, 77.66%) had replaced Proteobacteria (68.65%, 68.69%) as the predominant phylum.

DISCUSSION

From birth to 21 days after birth, oropharyngeal mother's milk administration did not change the diversity and structural composition of the oral microbiota. The oral microbial diversity of infants declined significantly over time. Firmicutes had replaced Proteobacteria as the predominant phylum.

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.

Crosstalk between COVID-19 and the gut-brain axis: a gut feeling

The microbes in the gut are crucial for maintaining the body's immune system and overall gut health. However, it is not fully understood how an unstable gut environment can lead to more severe cases of SARS-CoV-2 infection. The gut microbiota also plays a role in the gut-brain axis and interacts with the central nervous system through metabolic and neuroendocrine pathways. The interaction between the microbiota and the host's body involves hormonal, immune, and neural pathways, and any disruption in the balance of gut bacteria can lead to dysbiosis, which contributes to pathogen growth. In this context, we discuss how dysbiosis could contribute to comorbidities that increase susceptibility to SARS-CoV-2. Probiotics and fecal microbiota transplantation have successfully treated infectious and non-infectious inflammatory-related diseases, the most common comorbidities. These treatments could be adjuvant therapies for COVID-19 infection by restoring gut homeostasis and balancing the gut microbiota.

Impact of evolution on lifestyle in microbiome

This chapter analyses the interaction between microbiota and humans from an evolutionary point of view. Long-term interactions between gut microbiota and host have been generated as a result of dietary choices through coevolutionary processes, where mutuality of advantage is essential. Likewise, the characteristics of the intestinal environment have made it possible to describe different intrahost evolutionary mechanisms affecting microbiota. For its part, the intestinal microbiota has been of great importance in the evolution of mammals, allowing the diversification of dietary niches, phenotypic plasticity and the selection of host phenotypes. Although the origin of the human intestinal microbial community is still not known with certainty, mother-offspring transmission plays a key role, and it seems that transmissibility between individuals in adulthood also has important implications. Finally, it should be noted that certain aspects inherent to modern lifestyle, including refined diets, antibiotic intake, exposure to air pollutants, microplastics, and stress, could negatively affect the diversity and composition of our gut microbiota. This chapter aims to combine current knowledge to provide a comprehensive view of the interaction between microbiota and humans throughout evolution.

Human milk microbiome: associations with maternal diet and infant growth

Introduction

Ingestion of human milk (HM) is identified as a significant factor associated with early infant gut microbial colonization, which has been associated with infant health and development. Maternal diet has been associated with the HM microbiome (HMM). However, a few studies have explored the associations among maternal diet, HMM, and infant growth during the first 6 months of lactation.

Methods

For this cross-sectional study, Mam-Mayan mother-infant dyads (n = 64) were recruited from 8 rural communities in the Western Highlands of Guatemala at two stages of lactation: early (6-46 days postpartum, n = 29) or late (109-184 days postpartum, n = 35). Recruited mothers had vaginally delivered singleton births, had no subclinical mastitis or antibiotic treatments, and breastfed their infants. Data collected at both stages of lactation included two 24-h recalls, milk samples, and infant growth status indicators: head-circumference-for-age-z-score (HCAZ), length-for-age-z-score (LAZ), and weight-for-age-z-score (WAZ). Infants were divided into subgroups: normal weight (WAZ ≥ -1SD) and mildly underweight (WAZ < -1SD), non-stunted (LAZ ≥ -1.5SD) and mildly stunted (LAZ < -1.5SD), and normal head-circumference (HCAZ ≥ -1SD) and smaller head-circumference (HCAZ < -1SD). HMM was identified using 16S rRNA gene sequencing; amplicon analysis was performed with the high-resolution ANCHOR pipeline, and DESeq2 identified the differentially abundant (DA) HMM at the species-level between infant growth groups (FDR < 0.05) in both early and late lactation.

Results

Using both cluster and univariate analyses, we identified (a) positive correlations between infant growth clusters and maternal dietary clusters, (b) both positive and negative associations among maternal macronutrient and micronutrient intakes with the HMM at the species level and (c) distinct correlations between HMM DA taxa with maternal nutrient intakes and infant z-scores that differed between breast-fed infants experiencing growth faltering and normal growth in early and late lactation.

Conclusion

Collectively, these findings provide important evidence of the potential influence of maternal diet on the early-life growth of breastfed infants via modulation of the HMM.

Maternal Phlorizin Intake Protects Offspring from Maternal Obesity-Induced Metabolic Disorders in Mice via Targeting Gut Microbiota to Activate the SCFA-GPR43 Pathway

Maternal obesity increases the risk of obesity and metabolic disorders (MDs) in offspring, which can be mediated by the gut microbiota. Phlorizin (PHZ) can improve gut dysbiosis and positively affect host health; however, its transgenerational metabolic benefits remain largely unclear. This study aimed to investigate the potential of maternal PHZ intake in attenuating the adverse impacts of a maternal high-fat diet on obesity-related MDs in dams and offspring. The results showed that maternal PHZ reduced HFD-induced body weight gain and fat accumulation and improved glucose intolerance and abnormal lipid profiles in both dams and offspring. PHZ improved gut dysbiosis by promoting expansion of SCFA-producing bacteria, Akkermansia and Blautia, while inhibiting LPS-producing and pro-inflammatory bacteria, resulting in significantly increased fecal SCFAs, especially butyric acid, and reduced serum lipopolysaccharide levels and intestinal inflammation. PHZ also promoted intestinal GLP-1/2 secretion and intestinal development and enhanced gut barrier function by activating G protein-coupled receptor 43 (GPR43) in the offspring. Antibiotic-treated mice receiving FMT from PHZ-regulated offspring could attenuate MDs induced by receiving FMT from HFD offspring through the gut microbiota to activate the GPR43 pathway. It can be regarded as a promising functional food ingredient for preventing intergenerational transmission of MDs and breaking the obesity cycle.

Transmission and dynamics of mother-infant gut viruses during pregnancy and early life

Early development of the gut ecosystem is crucial for lifelong health. While infant gut bacterial communities have been studied extensively, the infant gut virome remains under-explored. To study the development of the infant gut virome over time and the factors that shape it, we longitudinally assess the composition of gut viruses and their bacterial hosts in 30 women during and after pregnancy and in their 32 infants during their first year of life. Using shotgun metagenomic sequencing applied to dsDNA extracted from Virus-Like Particles (VLPs) and bacteria, we generate 205 VLP metaviromes and 322 total metagenomes. With this data, we show that while the maternal gut virome composition remains stable during late pregnancy and after birth, the infant gut virome is dynamic in the first year of life. Notably, infant gut viromes contain a higher abundance of active temperate phages compared to maternal gut viromes, which decreases over the first year of life. Moreover, we show that the feeding mode and place of delivery influence the gut virome composition of infants. Lastly, we provide evidence of co-transmission of viral and bacterial strains from mothers to infants, demonstrating that infants acquire some of their virome from their mother's gut.

Antibiotic consumption in the first months of life: A cross-sectional study

INTRODUCTION

The factors and patterns associated with antibiotic consumption in infants are unclear. Our aim was to assess the cumulative incidence of antibiotic consumption from birth to 16 months and identify factors associated with antibiotic consumption among infants aged 4-16 months.

MATERIAL AND METHODS

We conducted a cross-sectional study in 2016 in a sample of 18 882 women from Galicia, Spain, who had given birth to a live child between September 1, 2015 and August 31, 2016. We calculated the cumulative incidence of antibiotic consumption based on maternal reports regarding the infant's consumption from birth to 14 months obtained through interviews; we did not estimate consumption at ages 15 and 16 months due to the small sample size. To assess which factors were associated with antibiotic consumption, we carried out a nested case-control study matching cases and controls for birth month on a 1:1 ratio.

RESULTS

The cumulative incidence of antibiotic consumption among infants aged 0-14 months increased from 7.5% to 66.0%. The case-control study included data for 1852 cases and 1852 controls. Daycare attendance (OR: 3.8 [95% CI: 3.2-4.6]), having older siblings (OR: 1.8 [95% CI: 1.6-2.1]), health care visits to private clinics (OR: 1.6 [95% CI: 1.4-2.0]), and passive smoking (OR: 1.3 [95% CI: 1.1-1.6]) were associated with an increased probability of antibiotic consumption. Maternal age between 30-39 years or 40 years and over at the time of birth was associated with a decreased probability of antibiotic consumption (OR: 0.8 [95% CI, 0.7-1.0] and OR: 0.6 [95% CI: 0.5-0.8], respectively).

CONCLUSIONS

Some of the factors associated with antibiotic consumption in infants are modifiable and should be considered in the development of public health measures aimed at reducing antibiotic consumption.

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.

The Role of Early Life Gut Mycobiome on Child Health

The human gut microbiota is composed of bacteria (microbiota or microbiome), fungi (mycobiome), viruses, and archaea, but most of the research is primarily focused on the bacterial component of this ecosystem. Besides bacteria, fungi have been shown to play a role in host health and physiologic functions. However, studies on mycobiota composition during infancy, the factors that might shape infant gut mycobiota, and implications to child health and development are limited. In this review, we discuss the factors likely shaping gut mycobiota, interkingdom interactions, and associations with child health outcomes and highlight the gaps in our current knowledge of this ecosystem.

Nutritional Approaches Targeting Gut Microbiota in Oxidative-Stress-Associated Metabolic Syndrome: Focus on Early Life Programming

Metabolic syndrome (MetS) denotes a constellation of risk factors associated with the development of cardiovascular disease, with its roots potentially traced back to early life. Given the pivotal role of oxidative stress and dysbiotic gut microbiota in MetS pathogenesis, comprehending their influence on MetS programming is crucial. Targeting these mechanisms during the early stages of life presents a promising avenue for preventing MetS later in life. This article begins by examining detrimental insults during early life that impact fetal programming, ultimately contributing to MetS in adulthood. Following that, we explore the role of oxidative stress and the dysregulation of gut microbiota in the initiation of MetS programming. The review also consolidates existing evidence on how gut-microbiota-targeted interventions can thwart oxidative-stress-associated MetS programming, encompassing approaches such as probiotics, prebiotics, postbiotics, and the modulation of bacterial metabolites. While animal studies demonstrate the favorable effects of gut-microbiota-targeted therapy in mitigating MetS programming, further clinical investigations are imperative to enhance our understanding of manipulating gut microbiota and oxidative stress for the prevention of MetS.

Epigenetic programming mediates abnormal gut microbiota and disease susceptibility in offspring with prenatal dexamethasone exposure

Prenatal dexamethasone exposure (PDE) can lead to increased susceptibility to various diseases in adult offspring, but its effect on gut microbiota composition and the relationship with disease susceptibility remains unclear. In this study, we find sex-differential changes in the gut microbiota of 6-month-old infants with prenatal dexamethasone therapy (PDT) that persisted in female infants up to 2.5 years of age with altered bile acid metabolism. PDE female offspring rats show abnormal colonization and composition of gut microbiota and increased susceptibility to cholestatic liver injury. The aberrant gut microbiota colonization in the PDE offspring can be attributed to the inhibited Muc2 expression caused by decreased CDX2 expression before and after birth. Integrating animal and cell experiments, we further confirm that dexamethasone could inhibit Muc2 expression by activating GR/HDAC11 signaling and regulating CDX2 epigenetic modification. This study interprets abnormal gut microbiota and disease susceptibility in PDT offspring from intrauterine intestinal dysplasia.

Microbiota-gut-brain axis and its therapeutic applications in neurodegenerative diseases

The human gastrointestinal tract is populated with a diverse microbial community. The vast genetic and metabolic potential of the gut microbiome underpins its ubiquity in nearly every aspect of human biology, including health maintenance, development, aging, and disease. The advent of new sequencing technologies and culture-independent methods has allowed researchers to move beyond correlative studies toward mechanistic explorations to shed light on microbiome-host interactions. Evidence has unveiled the bidirectional communication between the gut microbiome and the central nervous system, referred to as the "microbiota-gut-brain axis". The microbiota-gut-brain axis represents an important regulator of glial functions, making it an actionable target to ameliorate the development and progression of neurodegenerative diseases. In this review, we discuss the mechanisms of the microbiota-gut-brain axis in neurodegenerative diseases. As the gut microbiome provides essential cues to microglia, astrocytes, and oligodendrocytes, we examine the communications between gut microbiota and these glial cells during healthy states and neurodegenerative diseases. Subsequently, we discuss the mechanisms of the microbiota-gut-brain axis in neurodegenerative diseases using a metabolite-centric approach, while also examining the role of gut microbiota-related neurotransmitters and gut hormones. Next, we examine the potential of targeting the intestinal barrier, blood-brain barrier, meninges, and peripheral immune system to counteract glial dysfunction in neurodegeneration. Finally, we conclude by assessing the pre-clinical and clinical evidence of probiotics, prebiotics, and fecal microbiota transplantation in neurodegenerative diseases. A thorough comprehension of the microbiota-gut-brain axis will foster the development of effective therapeutic interventions for the management of neurodegenerative diseases.

Skin microbe-dependent TSLP-ILC2 priming axis in early life is co-opted in allergic inflammation

Although early life colonization of commensal microbes contributes to long-lasting immune imprinting in host tissues, little is known regarding the pathophysiological consequences of postnatal microbial tuning of cutaneous immunity. Here, we show that postnatal exposure to specific skin commensal Staphylococcus lentus (S. lentus) promotes the extent of atopic dermatitis (AD)-like inflammation in adults through priming of group 2 innate lymphoid cells (ILC2s). Early postnatal skin is dynamically populated by discrete subset of primed ILC2s driven by microbiota-dependent induction of thymic stromal lymphopoietin (TSLP) in keratinocytes. Specifically, the indole-3-aldehyde-producing tryptophan metabolic pathway, shared across Staphylococcus species, is involved in TSLP-mediated ILC2 priming. Furthermore, we demonstrate a critical contribution of the early postnatal S. lentus-TSLP-ILC2 priming axis in facilitating AD-like inflammation that is not replicated by later microbial exposure. Thus, our findings highlight the fundamental role of time-dependent neonatal microbial-skin crosstalk in shaping the threshold of innate type 2 immunity co-opted in adulthood.

The impact of gut microbial signals on hematopoietic stem cells and the bone marrow microenvironment

Hematopoietic stem cells (HSCs) undergo self-renewal and differentiation in the bone marrow, which is tightly regulated by cues from the microenvironment. The gut microbiota, a dynamic community residing on the mucosal surface of vertebrates, plays a crucial role in maintaining host health. Recent evidence suggests that the gut microbiota influences HSCs differentiation by modulating the bone marrow microenvironment through microbial products. This paper comprehensively analyzes the impact of the gut microbiota on hematopoiesis and its effect on HSCs fate and differentiation by modifying the bone marrow microenvironment, including mechanical properties, inflammatory signals, bone marrow stromal cells, and metabolites. Furthermore, we discuss the involvement of the gut microbiota in the development of hematologic malignancies, such as leukemia, multiple myeloma, and lymphoma.

Supplemented Infant Formula and Human Breast Milk Show Similar Patterns in Modulating Infant Microbiota Composition and Function In Vitro

The gut microbiota of healthy breastfed infants is often dominated by bifidobacteria. In an effort to mimic the microbiota of breastfed infants, modern formulas are fortified with bioactive and bifidogenic ingredients. These ingredients promote the optimal health and development of infants as well as the development of the infant microbiota. Here, we used INFOGEST and an in vitro batch fermentation model to investigate the gut health-promoting effects of a commercial infant formula supplemented with a blend containing docosahexaenoic acid (DHA) (20 mg/100 kcal), polydextrose and galactooligosaccharides (PDX/GOS) (4 g/L, 1:1 ratio), milk fat globule membrane (MFGM) (5 g/L), lactoferrin (0.6 g/L), and Bifidobacterium animalis subsp. lactis, BB-12 (BB-12) (106 CFU/g). Using fecal inoculates from three healthy infants, we assessed microbiota changes, the bifidogenic effect, and the short-chain fatty acid (SCFA) production of the supplemented test formula and compared those with data obtained from an unsupplemented base formula and from the breast milk control. Our results show that even after INFOGEST digestion of the formula, the supplemented formula can still maintain its bioactivity and modulate infants' microbiota composition, promote faster bifidobacterial growth, and stimulate production of SCFAs. Thus, it may be concluded that the test formula containing a bioactive blend promotes infant gut microbiota and SCFA profile to something similar, but not identical to those of breastfed infants.

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.

Exposure to prescribed medication in early life and impacts on gut microbiota and disease development

The gut microbiota during early life plays a crucial role in infant development. This microbial-host interaction is also essential for metabolism, immunity, and overall human health in later life. Early-life pharmaceutical exposure, mainly referring to exposure during pregnancy, childbirth, and infancy, may change the structure and function of gut microbiota and affect later human health. In this Review, we describe how healthy gut microbiota is established in early life. We summarise the commonly prescribed medications during early life, including antibiotics, acid suppressant medications and other medications such as antidepressants, analgesics and steroid hormones, and discuss how these medication-induced changes in gut microbiota are involved in the pathological process of diseases, including infections, inflammatory bowel disease, metabolic diseases, allergic diseases and neurodevelopmental disorders. Finally, we review some critical methods such as dietary therapy, probiotics, prebiotics, faecal microbiota transplantation, genetically engineered phages, and vagus nerve stimulation in early life, aiming to provide a new strategy for the prevention of adverse health outcomes caused by prescribed medications exposure in early life.

Comparative Analysis of Outpatient Antibiotic Prescribing in Early Life: A Population-Based Study Across Birth Cohorts in Denmark and Germany

INTRODUCTION

Comparing antibiotic prescribing between countries can provide important insights into potential needs of improving antibiotic stewardship programs. We aimed to compare outpatient antibiotic prescribing in early life between children born in Denmark and Germany.

METHODS

Using the Danish nationwide healthcare registries and a German claims database (GePaRD, ~ 20% population coverage), we included children born between 2004 and 2016, and followed them regarding outpatient antibiotic prescriptions until end of enrollment or the end of 2018. We then determined the median time to first antibiotic prescription. Based on all prescriptions in the first 2 years of life, we calculated the rate of antibiotic treatment episodes and for the children's first prescriptions in this period, we determined established quality indicators. All analyses were stratified by birth year and country.

RESULTS

In the 2016 birth cohorts, the median time to first antibiotic prescription was ~ 21 months in Denmark and ~ 28 in Germany; the rate of antibiotic treatment episodes per 1000 person-years was 537 in Denmark and 433 in Germany; the percentage of prescribed antibiotics with higher concerns regarding side effects and/or resistance potential was 6.2% in Denmark and 44.2% in Germany. In the 2016 birth cohorts, the age at first antibiotic prescription was 50-59% higher compared to the 2004 birth cohorts; the rate of antibiotic treatment episodes was 43-44% lower.

CONCLUSIONS

Infants in Denmark received antibiotics markedly earlier and more frequently than in Germany, while quality indicators of antibiotic prescribing were more favorable in Denmark. Although both countries experienced positive changes towards more rational antibiotic prescribing in early life, our findings suggest potential for further improvement. This particularly applies to prescribing antibiotics with a lower potential for side effects and/or resistance in Germany.

Sialyllactose Enhances the Short-Chain Fatty Acid Production and Barrier Function of Gut Epithelial Cells via Nonbifidogenic Modification of the Fecal Microbiome in Human Adults

Although various benefits of human milk oligosaccharides (HMOs) have been reported, such as promoting Bifidobacterium growth in the infant gut, their effects on adults have not been fully studied. This study investigated the effects of two types of sialyllactose, 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL), on the adult intestinal microbiome using the simulator of human intestinal microbial ecosystem (SHIME®), which can simulate human gastrointestinal conditions. HPLC metabolite analysis showed that sialyllactose (SL) supplementation increased the short-chain fatty acid content of SHIME culture broth. Moreover, 16S rRNA gene sequencing analysis revealed that SL promoted the growth of Phascolarctobacterium and Lachnospiraceae, short-chain fatty acid-producing bacteria, but not the growth of Bifidobacterium. Altogether, both types of SL stimulated an increase in short-chain fatty acids, including propionate and butyrate. Additionally, SHIME culture supernatant supplemented with SL improved the intestinal barrier function in Caco-2 cell monolayers. These results suggest that SL could act as a unique prebiotic among other HMOs with a nonbifidogenic effect, resulting in intestinal barrier protection.

Evaluation of Prebiotic Potential of Crude Polysaccharides Extracted from Wild Lentinus polychrous and Lentinus squarrosulus and Their Application for a Formulation of a Novel Lyophilized Synbiotic

Edible mushrooms, including wild mushrooms, are currently being investigated as natural sources to evaluate their prebiotic potential. This study aimed to evaluate the prebiotic potential of crude polysaccharides (CPSs) extracted from wild Lentinus squarrosulus UBU_LS1 and Lentinus polychrous UBU_LP2 and their application as cryoprotectants in the freeze-drying process to formulate a novel synbiotic product. Based on fruiting body morphology and molecular identification, two wild edible mushrooms named UBU_LS1 and UBU_LP2 were identified as Lentinus squarrosulus and Lentinus polychrous, respectively. L. squarrosulus UBU_LS1 and L. polychrous UBU_LP2 contained high amounts of CPS after hot water extraction. Monosaccharide component analysis showed that CPS_UBU_LS1 and CPS_UBU_LP2 were typical heteropolysaccharides. CPS_UBU_LS1 and CPS_UBU_LP2 showed hydrolysis tolerance to the simulated human gastric acidic pH solution, indicating that these CPSs are capable of reaching the lower gastrointestinal tract. Antioxidant activity determined using the 1,1-diphenyl-2-picrylhydrazyl assay revealed that the CPS_UBU_LS1 and CPS_UBU_LP2 displayed greater antioxidant activity comparable with that of ascorbic acid. It was found that CPS_UBU_LS1 and CPS_UBU_LP2 have a high potential for stimulating growth in all probiotic strains. Moreover, both CPS compounds could possibly be used as cryoprotectants in freeze drying, since the viability of the selected probiotic L. fermentum 47-7 exhibited cell survival of greater than 70% after 90 days of storage at 4 °C. These results highlight that wild edible mushrooms L. squarrosulus UBU_LS1 and L. polychrous UBU_LP2 are potential natural sources of prebiotics and can be applied as cryoprotectants in the freeze-drying process. The crude polysaccharide derived from this study could also be considered as a potent antioxidative compound. Therefore, our study provides evidence to support the application of CPSs from wild edible mushrooms in synbiotic product development and in various functional foods. Finally, further evaluation of these prebiotics, including the determination of the potential rehabilitation of beneficial gut microbes in diseased individuals, is currently being conducted by our research group.

Prenatal per- and polyfluoroalkyl substances exposure and gut microbiota of infants: A prospective cohort study

Prenatal exposure to per- and polyfluoroalkyl substances (PFASs) has been reported to be linked to a series of adverse health outcomes in mothers and their children. As the gut microbiota is a sensitive biomarker for assessing the toxicity of environmental contaminants, this study attempted to investigate whether prenatal PFASs exposure was associated with the gut microbiota of infants. Based on the Shanghai-Minhang Birth Cohort Study, this prospective cohort study included 69 mother-infant pairs. Fasting blood samples were collected from pregnant women for the PFASs assay. We collected fecal samples of infants at 1 year of age and analyzed the V3-V4 hypervariable region of the bacterial 16 S rRNA gene by high-throughput sequencing. Among the detected 11 PFASs, the concentration of perfluorooctanoic acid (22.19 ng/mL) was the highest, followed by perfluorooctane sulfonic acid (12.08 ng/mL). Compared with infants whose mothers' total PFASs concentrations during pregnancy were at the 40th percentile or lower (reference group), the species richness and diversity of microbiota were lower in infants prenatally exposed to a high level of PFASs (the sum of PFASs concentrations above the 60th percentile). Prenatal exposure to PFASs was associated with a higher proportion of Acidaminococcaceae, Acidaminococcus, Megamonas, Megasphaera micronuciformis and Megamonas funiformis in infants. The changes of the species have been suggested to be associated with immune and metabolic dysfunction in humans. Functional alterations of gut microbiota due to PFASs exposure were dominated by an enrichment of butanoate metabolism. Our preliminary findings may shed light on the potential role of the microbiota underlying the well-known impact of prenatal PFASs exposure on health outcomes of humans in later life.

Host-gut microbiota interactions during pregnancy

Mammalian pregnancy is characterized by a well-known suite of physiological changes that support fetal growth and development, thereby positively affecting both maternal and offspring fitness. However, mothers also experience trade-offs between current and future maternal reproductive success, and maternal responses to these trade-offs can result in mother-offspring fitness conflicts. Knowledge of the mechanisms through which these trade-offs operate, as well as the contexts in which they operate, is critical for understanding the evolution of reproduction. Historically, hormonal changes during pregnancy have been thought to play a pivotal role in these conflicts since they directly and indirectly influence maternal metabolism, immunity, fetal growth and other aspects of offspring development. However, recent research suggests that gut microbiota may also play an important role. Here, we create a foundation for exploring this role by constructing a mechanistic model linking changes in maternal hormones, immunity and metabolism during pregnancy to changes in the gut microbiota. We posit that marked changes in hormones alter maternal gut microbiome composition and function both directly and indirectly via impacts on the immune system. The gut microbiota then feeds back to influence maternal immunity and metabolism. We posit that these dynamics are likely to be involved in mediating maternal and offspring fitness as well as trade-offs in different aspects of maternal and offspring health and fitness during pregnancy. We also predict that the interactions we describe are likely to vary across populations in response to maternal environments. Moving forward, empirical studies that combine microbial functional data and maternal physiological data with health and fitness outcomes for both mothers and infants will allow us to test the evolutionary and fitness implications of the gestational microbiota, enriching our understanding of the ecology and evolution of reproductive physiology.

The neonatal gut microbiome and global health

The role of gut microbiome in health, a century-old concept, has been on the center stage of medical research recently. While different body sites, disease conditions, and populations have been targeted, neonatal and early infancy appear to be the most suitable period for such interventions. It is intriguing to note that, unlike traditional use in diarrhea and maintenance of gastrointestinal health, microbiome-mediating therapies have now addressed the most serious medical conditions in young infants such as necrotizing enterocolitis and neonatal sepsis. Unfortunately, almost all new endeavors in this space have been carried out in the Western world leaving behind millions of neonates that can benefit from such manipulations while serving as a large resource for further learning. In this review, an attempt has been made to quantify the global burden of neonatal morbidity and mortality, examples presented on interventions that have failed as a result of drawing from studies conducted in the West, and a case made for manipulating the neonatal gut microbiome to address the biggest killers in early life. A brief comparative analysis has been made to demonstrate the differences in the gut microbiota of North and South and a large clinical trial of synbiotics conducted by our group in a South Asian setting has been presented. Although challenging, the value of conducting such global health research is introduced with an intent to invite medical scientists to engage in well-planned, scientifically robust research endeavors. This can bring about innovation while saving and serving the most vulnerable citizens now and protecting them from the negative health consequences in the later part of their lives, ultimately shaping a resilient and equitable world as pledged by 193 United Nations member countries in 2015.

The human gut microbiome and aging

The composition of the human gut microbiome has been observed to change over the course of an individual's life. From birth, it is shaped by mode of delivery, diet, environmental exposures, geographic location, exposures to medications, and by aging itself. Here, we present a narrative review of the gut microbiome across the lifespan with a focus on its impacts on aging and age-related diseases in humans. We will describe how it is shaped, and features of the gut microbiome that have been associated with diseases at different phases of life and how this can adversely affect healthy aging. Across the lifespan, and especially in old age, a diverse microbiome that includes organisms suspected to produce anti-inflammatory metabolites such as short-chain fatty acids, has been reported to be associated with healthy aging. These findings have been remarkably consistent across geographic regions of the world suggesting that they could be universal features of healthy aging across all cultures and genetic backgrounds. Exactly how these features of the microbiome affect biologic processes associated with aging thus promoting healthy aging will be crucial to targeting the gut microbiome for interventions that will support health and longevity.