Development of the gut microbiota in infancy and its impact on health in later life

Chronic nasal inflammation early in life induces transient and long-term dysbiosis of gut microbiota in mice

The gut microbiota begins to colonize the host body following birth, develops during the suckling period and changes to the adult type after weaning. The early gut microbiota during the suckling period is thought to have profound effects on the host physiology throughout life but it is still unclear whether early dysbiosis is retained lifelong. Our previous study indicated that chronic nasal inflammation induces dysbiosis of gut microbiota in adult mice. In the present study, we addressed the question as to whether early exposure to chronic nasal inflammation induces dysbiosis, and if so, whether the dysbiosis is retained until adulthood and the sex differences in this effect. Male and female mice received repeated intranasal administration of lipopolysaccharide (LPS) or saline twice a week from P7 to P24 and were weaned at P24. The cecal contents were obtained for 16S rRNA analysis at 2 time points: at 4 weeks (wks), just after weaning, and at maturation to adulthood at 10 wks. The body weight did not differ between saline- and LPS-treated mice till around weaning, suggesting that the mothers' milk was given similarly to all mice. At 4 wks, the beta diversity was significantly different between saline- and LPS-treated male and female mice and the composition of the gut microbiota changed in LPS-treated mice. The abundance of phylum Bacteroidota tended to decrease and that of Firmicutes increased in LPS-treated male mice, while the abundance of Deferribacterota increased in LPS-treated female mice. At 10 wks, the beta diversity was not different between saline- and LPS-treated mice, but the abundance of family Lachnospiraceae significantly decreased in LPS-treated male and female mice by LEfSe analysis. Together, chronic nasal inflammation early in life caused transient and long-term dysbiosis of gut microbiota, which may contribute to the onset and progress of metabolic and neuropsychiatric disorders.

The association of infant and mother gut microbiomes with development of allergic diseases in children: a systematic review

OBJECTIVE

It is believed that gut microbiota alteration leads to both intestinal and non-intestinal diseases in children. Since infants inherit maternal microbiota during pregnancy and lactation, recent studies suggest that changes in maternal microbiota can cause immune disorders as well. This systematic review was designed to assess the association between the child and mother's gut microbiome and allergy development in childhood.

DATA SOURCES

In this systematic review, international databases including PubMed, Scopus, and ISI/WOS were searched until January 2023 to identify relevant studies.

STUDY SELECTIONS

Observational studies that analyzed infant or maternal stool microbiome and their association with allergy development in children were included in this study. Data extraction and quality assessment of the included studies were independently conducted by two researchers.

RESULTS

Of the 1694 papers evaluated, 21 studies examined neonate gut microbiome by analyzing stool samples and six studies examined maternal gut microbiota. A total of 5319 participants were included in this study. Asthma followed by eczema and dermatitis were the most common allergy disorders among children. Urbanization caused a lack of diversity in the bacterial microbiota as well as lower levels of Bifidobacterium and Lachnospira associated with a higher risk of allergy. In contrast, higher levels of Roseburia and Flavonifractor were associated with lower allergy risk.

CONCLUSIONS

This systematic review shows that gut microbiota may be associated with allergy development. Further studies are required to provide a definitive answer.

The effect of oral probiotics in the last trimester on the human milk and infant gut microbiotas at six months postpartum: A randomized controlled trial

Objective

The main aim of this study was to evaluate the effect of oral probiotics on the human milk microbiota and determine whether that influenced infant microbiota development.

Methods

A total of 27 pregnant women were recruited; 14 were assigned to the probiotic group, and the rest were assigned to the control group. Their infants were likewise assigned to the probiotic group or the control group. Pregnant women in the probiotic group received probiotic supplementation from 32 weeks of gestation until delivery. Human milk samples and infant fecal samples were collected at 6 months after delivery, and 16S rRNA sequencing was used to analyze the composition of the human milk and infant gut microbiota (NCT06241222).

Results

In the control group, bacterial microbiota were detected in 8 out of 13 milk samples, whereas in the probiotic group, only 6 out of 14 milk samples contained bacterial microbiota. We examined the composition of the human milk and infant gut microbiota in both the control and probiotic groups. Spearman correlation analysis revealed that various genera in human milk were correlated with the infant gut microbiota. The Linear discriminant analysis effect size (LEfSe) showed that 6 bacteria in the human milk microbiota in the control group were significantly more abundant than those in the probiotic group. Nine bacteria were significantly more abundant in the human milk microbiota in the probiotic group than the control group. According to the LEfSe results, 11 bacteria in the infant gut microbiota in the control group were significantly more abundant than those in the probiotic group. Fourteen bacteria were significantly more abundant in the infant gut microbiota in the probiotic group than in the control group.

Conclusion

The infant gut microbiota at 6 months has a complicated relationship with the maternal human milk microbiota. Oral probiotic supplementation can change the composition of the human milk microbiota and the infant gut microbiota.

Characterization of Swarna Bhasma and Swarnaprash and Determination of Antimicrobial Properties Against Gut-Pathobiont and Symbiont

Ayurveda has a long-standing tradition of healthcare in Southeast Asia. Swarnaprash, a classical Ayurveda preparation, is commonly given as the pre-lacteal feed to neonates to prevent labor-related complications and infections. It comprises incinerated gold particles (InAuP/Swarna Bhasma), honey (Madhu), and clarified butter oil (CBO/Cow Ghrita). This in vitro study aimed to evaluate the therapeutic potential of the individual ingredients and combinations of Swarnaprash against selected neonatal gut pathobionts and symbionts. The study employed sophisticated instruments, including SEM with EDAX and X-ray diffraction analysis, to investigate the shape and structural disparities in the ingredients of Swarnaprash. The reported size of gold particles in Swarnaprash ranges from 0.6 to 9.5 µm. These particles are relatively smaller than those in Swarna Bhasma but larger than synthetic gold particles. Swarnaprash demonstrated both bactericidal and bacteriostatic activity against selected neonatal gut pathobionts, with the largest inhibition zones observed for P. aeruginosa and S. Typhi. It surpassed the individual efficacy of its components-Prash, InAuPs, honey, or CBO alone. Notably, Swarnaprash did not affect the selected beneficial gut bacteria. The results warrant further in vivo and clinical studies to explore the effects of Swarnaprash on neonatal gut flora, which would provide vital information for research in neonatal healthcare.

Preventive and Therapeutic Effects of Lactiplantibacillus plantarum HD02 and MD159 through Mast Cell Degranulation Inhibition in Mouse Models of Atopic Dermatitis

As the relationship between the gut microbiome and allergies becomes better understood, targeted strategies to prevent and treat allergies through gut microbiome modulation are being increasingly developed. In the study presented herein, we screened various probiotics for their ability to inhibit mast cell degranulation and identified Lactiplatibacillus plantarum HD02 and MD159 as effective candidates. The two strains significantly attenuated vascular permeability induced by mast cell degranulation in a passive cutaneous anaphylaxis (PCA) model and, in the MC903-induced murine atopic dermatitis (AD) model, demonstrated comparable preventive effects against allergies, reducing blood levels of MCPT-1 (mast cell protease-1) and total IgE. In the house dust mite (HDM)-induced murine AD model, both L. plantarum HD02 and MD159 showed therapeutic effects, with L. plantarum HD02 demonstrating superior efficacy. Nevertheless, L. plantarum MD159 better suppressed transepidermal water loss (TEWL). Furthermore, L. plantarum HD02 and MD159 significantly increased the number of splenic Foxp3+ regulatory T cells, with L. plantarum MD159 having a more pronounced effect. However, only L. plantarum HD02 achieved a reduction in immune cells in the draining lymph nodes. Our findings highlight L. plantarum HD02 and MD159 as promising candidates for the prevention and treatment of allergies, demonstrating significant efficacy in suppressing mast cell degranulation, reducing the number of allergy biomarkers, and modulating immune responses in experimental models of AD. Their distinct mechanisms of action suggest potential complementary roles in addressing allergic diseases, underscoring their therapeutic promise in clinical applications.

Perinatal Exposure to Phenols and Poly- and Perfluoroalkyl Substances and Gut Microbiota in One-Year-Old Children

The role of the gut microbiota in human health calls for a better understanding of its determinants. In particular, the possible effects of chemicals with widespread exposure other than pharmaceuticals are little known. Our aim was to characterize the sensitivity of the early-life gut microbiota to specific chemicals with possible antimicrobial action. Within the SEPAGES French couple-child cohort, we assessed 12 phenols in repeated urine samples from 356 pregnant women and their offspring and 19 poly- and perfluoroalkyl substances (PFASs) in serum from the pregnant women. We collected stool samples from the children at one year of age, in which the V3-V4 region of the 16S rRNA gene was sequenced, allowing for gut bacterial profiling. Associations of each chemical with α- and β-diversity indices of the gut microbiota and with the relative abundance of the most abundant taxa were assessed using single-pollutant and mixture (BKMR) models. Perinatal exposure to certain parabens was associated with gut microbiota α- and β-diversity and with Firmicutes and Proteobacteria. Suggestive associations of certain phenols with genera of the Lachnospiraceae and Enterobacteriaceae families were observed, but these were not maintained after correction for multiple testing. Parabens, which have known antimicrobial properties, might disrupt the child gut microbiota, but larger studies are required to confirm these findings.

Prenatal stress impacts foetal neurodevelopment: Temporal windows of gestational vulnerability

Prenatal maternal stressors ranging in severity from everyday occurrences/hassles to the experience of traumatic events negatively impact neurodevelopment, increasing the risk for the onset of psychopathology in the offspring. Notably, the timing of prenatal stress exposure plays a critical role in determining the nature and severity of subsequent neurodevelopmental outcomes. In this review, we evaluate the empirical evidence regarding temporal windows of heightened vulnerability to prenatal stress with respect to motor, cognitive, language, and behavioural development in both human and animal studies. We also explore potential temporal windows whereby several mechanisms may mediate prenatal stress-induced neurodevelopmental effects, namely, excessive hypothalamic-pituitary-adrenal axis activity, altered serotonin signalling and sympathetic-adrenal-medullary system, changes in placental function, immune system dysregulation, and alterations of the gut microbiota. While broadly defined developmental windows are apparent for specific psychopathological outcomes, inconsistencies arise when more complex cognitive and behavioural outcomes are considered. Novel approaches to track molecular markers reflective of the underlying aetiologies throughout gestation to identify tractable biomolecular signatures corresponding to critical vulnerability periods are urgently required.

Use of Cosmetics in Pregnancy and Neurotoxicity: Can It Increase the Risk of Congenital Enteric Neuropathies?

Pregnancy is a particularly vulnerable period for the growing fetus, when exposure to toxic agents, especially in the early phases, can decisively harm embryo development and compromise the future health of the newborn. The inclusion of various chemical substances in personal care products (PCPs) and cosmetic formulations can be associated with disruption and damage to the nervous system. Microplastics, benzophenones, parabens, phthalates and metals are among the most common chemical substances found in cosmetics that have been shown to induce neurotoxic mechanisms. Although cosmetic neurotoxin exposure is believed to be minimal, different exposure scenarios of cosmetics suggest that these neurotoxins remain a threat. Special attention should be paid to early exposure in the first weeks of gestation, when critical processes, like the migration and proliferation of the neural crest derived cells, start to form the ENS. Importantly, cosmetic neurotoxins can cross the placental barrier and affect the future embryo, but they are also secreted in breast milk, so babies remain exposed for longer periods, even after birth. In this review, we explore how neurotoxins contained in cosmetics and PCPs may have a role in the pathogenesis of various neurodevelopmental disorders and neurodegenerative diseases and, therefore, also in congenital enteric aganglionosis as well as in postnatal motility disorders. Understanding the mechanisms of these chemicals used in cosmetic formulations and their role in neurotoxicity is crucial to determining the safety of use for cosmetic products during pregnancy.

Polyphenols: Secondary Metabolites with a Biological Impression

Polyphenols are natural compounds which are plant-based bioactive molecules, and have been the subject of growing interest in recent years. Characterized by multiple varieties, polyphenols are mostly found in fruits and vegetables. Currently, many diseases are waiting for a cure or a solution to reduce their symptoms. However, drug or other chemical strategies have limitations for using a treatment agent or still detection tool of many diseases, and thus researchers still need to investigate preventive or improving treatment. Therefore, it is of interest to elucidate polyphenols, their bioactivity effects, supplementation, and consumption. The disadvantage of polyphenols is that they have a limited bioavailability, although they have multiple beneficial outcomes with their bioactive roles. In this context, several different strategies have been developed to improve bioavailability, particularly liposomal and nanoparticles. As nutrition is one of the most important factors in improving health, the inclusion of plant-based molecules in the daily diet is significant and continues to be enthusiastically researched. Nutrition, which is important for individuals of all ages, is the key to the bioactivity of polyphenols.

Pre- to Postbiotics: The Beneficial Roles of Pediatric Dysbiosis Associated with Inflammatory Bowel Diseases

Probiotics are "live microorganisms which, when administered in adequate amount, confer health benefits on the host". They can be found in certain foods like yogurt and kefir and in dietary supplements. The introduction of bacterial derivatives has not only contributed to disease control but has also exhibited promising outcomes, such as improved survival rates, immune enhancement, and growth promotion effects. It is interesting to note that the efficacy of probiotics goes beyond the viability of the bacteria, giving rise to concepts like paraprobiotics, non-viable forms of probiotics, and postbiotics. Paraprobiotics offer various health benefits in children with intestinal dysbiosis, contributing to improved digestive health, immune function, and overall well-being. In this review, the potential of these therapeutic applications as alternatives to pharmacological agents for treating pediatric intestinal dysbiosis will be thoroughly evaluated. This includes an analysis of their efficacy, safety, long-term benefits, and their ability to restore gut microbiota balance, improve digestive health, enhance immune function, and reduce inflammation. The aim is to determine if these non-pharmacological interventions can effectively and safely manage intestinal dysbiosis in children, reducing the need for conventional medications and their side effects.

Exploring the relationship between gut microbial ecology and inflammatory disease: An insight into health and immune function

The immune system, host brain development, and general metabolism are all influenced by the gut bacteria. Bacteria make up the majority of the gut microbiota in mammals. The mouse has been the most often used animal model in preclinical biological research. In mice, Firmicutes and Clostridiales are prominent. On the other hand, Bacteroidaceae, Prevotellaceae, and Firmicutes are commonly found in humans. In this review, we performed a detailed study by focusing on a comparison between human and murine gut microbiomes, role of the microbiome and their secreted metabolites in regulating gut immunity to maintain homeostasis, and changes in the microbial composition in the dysbiotic state.

Knowledge, attitude, and practice of Chinese parents with infants (aged 0-3 years) toward immunity, gut microbiota and biotics: a comprehensive study

In the wake of the COVID-19 pandemic, there has been an increasing focus towards infant immunity. The development and maintenance of the immune system are significantly influenced from birth, and is shaped by early-life infant feeding behavior. Hence, the knowledge, attitude, and practice (KAP) of parents play a crucial role in shaping the immune system of infants. A total of 2369 parents across 19 cities in China were surveyed using a self-designed online questionnaire. The KAP questionnaire assessed three domains: immunity, gut microbiota, and biotics (prebiotics, probiotics, and synbiotics). The questionnaire also included questions on infant health. An overwhelming majority of parents (97.90%) placed high value on their children's immunity, and 40.40% of them reported an increased level of concern following the COVID-19 pandemic. Diarrhea (78.80%), colds (75.70%), nighttime crying (73.80%), regurgitation (71.70%) and food retention (66.50%) were the major health issues reported. Knowledge scores toward immunity and gut microbiota were positively correlated to attitude and practice scores, respectively. Attitude scores toward immunity, gut microbiota and biotics were positively correlated to their respective practice scores. Parental knowledge score on immunity was negatively correlated with diarrhea, colds, regurgitation and food retention. On the other hand, parental practice scores toward immunity were negatively correlated with food retention. In regards to gut microbiota, parental knowledge score was negatively correlated with diarrhea, regurgitation and food retention; parental attitude score was negatively correlated with nighttime crying whereas practice score was negatively correlated with diarrhea, regurgitation, food retention and nighttime crying. Attitude score toward biotics was negatively correlated with nighttime crying and practice scores toward biotics was negatively correlated with colds, food retention and nighttime crying. This study demonstrated that significant gaps and misunderstandings exist among parents regarding immunity, gut microbiota health, and biotics. Both public education and interventions are crucial to enhance parental knowledge and practices, thereby improving infant immunity.

Association Between Gut and Nasal Microbiota and Allergic Rhinitis: A Systematic Review

Allergic rhinitis is a chronic non-infectious inflammation of the nasal mucosa mediated by specific IgE. Recently, the human microbiome has drawn broad interest as a potential new target for treating this condition. This paper succinctly summarizes the main findings of 17 eligible studies published by February 2024, involving 1044 allergic rhinitis patients and 954 healthy controls from 5 countries. These studies examine differences in the human microbiome across important mucosal interfaces, including the nasal and intestinal areas, between patients and controls. Overall, findings suggest variations in the gut microbiota between allergic rhinitis patients and healthy individuals, although the specific bacterial taxa that significantly changed were not always consistent across studies. Due to the limited scope of existing research and patient coverage, the relationship between the nasal microbiome and allergic rhinitis remains inconclusive. The article discusses the potential immune-regulating role of the gut microbiome in allergic rhinitis. Further well-designed clinical trials with large-scale recruitment of allergic rhinitis patients are encouraged.

The role of Bifidobacterium in longevity and the future of probiotics

This review explores the role and health impacts of probiotics, focusing specifically on Bifidobacterium spp. It highlights the functionalities that Bifidobacteria can provide, underscored by the historical evolution of definitions and technological advancements related to probiotics. By examining the association between Bifidobacteria and longevity, this review suggests new avenues for health enhancement. Highlighting case studies of centenarians, it presents examples related to human aging, illuminating the potential links to longevity through research on Bifidobacterium strains found in centenarians. This review not only emphasizes the importance of current research but also advocates for further investigation into the health benefits of Bifidobacteria, underlining the necessity for continuous study in the nutraceutical field.

Examining the Efficacy of Five Lactobacillus Species in Treating and Preventing Atopic Dermatitis: A Systemic Literature Review

Probiotics have garnered increasing attention, particularly within the realm of atopic dermatitis (AD). Although classified as dietary supplements by the Food and Drug Administration, probiotics are being explored for their potential to modify immune system responses and aid in disease recovery. This review aims to provide a current understanding of probiotics, specifically various lactobacilli strains, as a therapeutic option in preventing and treating AD. The concept of the gut-skin axis has gained substantial recognition, emphasizing the complex relationship between the gut microbiome and skin health. Dysfunctional gut barriers and metabolites produced by gut microorganisms can exert profound influences on skin conditions, including AD. Lactobacilli species are particularly noteworthy for their resilience and stability within the gastrointestinal tract, making these bacteria ideal candidates for probiotic supplementation. Various lactobacilli strains (Lactobacillus salivarius, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus reuteri, and Lactobacillus rhamnosus) were included in this study due to their current uses in mitigating AD symptomatology. This systemic review article aims to shed light on the potential of probiotics as a therapeutic approach for AD, highlighting their stellar safety profile and promising therapeutic efficacy. Given the compelling preliminary findings and the constraints associated with conventional treatments, probiotics, particularly lactobacilli strains, emerge as a considerable alternative or adjuvant option for individuals grappling with AD. Further exploration is imperative to establish probiotics as a promising therapeutic option, providing renewed hope for those seeking effective strategies for managing AD.

Longitudinal Correlations between Molecular Compositions of Stratum Corneum and Breast Milk Factors during Infancy: A Prospective Birth Cohort Study

Breast milk contains numerous factors that are involved in the maturation of the immune system and development of the gut microbiota in infants. These factors include transforming growth factor-β1 and 2, immunoglobin A, and lactoferrin. Breast milk factors may also affect epidermal differentiation and the stratum corneum (SC) barrier in infants, but no studies examining these associations over time during infancy have been reported. In this single-center exploratory study, we measured the molecular components of the SC using confocal Raman spectroscopy at 0, 1, 2, 6, and 12 months of age in 39 infants born at our hospital. Breast milk factor concentrations from their mothers' breast milk were determined. Correlation coefficients for the two datasets were estimated for each molecular component of the SC and breast milk factor at each age and SC depth. The results showed that breast milk factors and molecular components of the SC during infancy were partly correlated with infant age in months and SC depth, suggesting that breast milk factors influence the maturation of the SC components. These findings may improve understanding of the pathogenesis of skin diseases associated with skin barrier abnormalities.

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.

Leucine Supplementation Modulates Lipid Metabolism and Inflammation in Early Weaning Piglets

Early weaning can induce the programmed dysregulation of glycolipid metabolism and inflammation in adult animals. The primary objective of this study was to evaluate the efficacy of leucine supplementation administered promptly after early weaning in mitigating these adverse effects in piglets. At day 21, 24 piglets were randomly selected and divided into 3 groups: EW group where the piglets were weaned at day 21 and fed basal diet, EWL group where the piglets were weaned at day 21 and fed the basal diet with supplementation of 1% leucine, and C group where the piglets were fed basal diet and weaned at 28 days. Each group contained eight replicates, with one piglet per replicate. The results indicated that early weaning had an impact on gut health and could activate the inhibitor of the kappa B kinase gamma/inhibitor kappa B alpha/NF-kappa-B (IKKγ/IκBα/NF-κB) signaling pathway to ameliorate pro-inflammatory factor and apoptosis levels. Furthermore, early weaning reduced the activity of fatty acid β oxidation (FAβO) and affected genes linked with lipid metabolism. Supplementing with leucine can improve the effects of these factors. In summary, leucine may alleviate the influences of early weaning on the lipid metabolism and inflammation in piglets.

de Vos W. Early-life gut microbiota associates with allergic rhinitis during 13-year follow-up in a Finnish probiotic intervention cohort

Perinatal and early-life factors reported to affect risk of allergic diseases may be mediated by changes in the gut microbiota. Here, we explored the associations between the infant gut microbiota and allergic morbidity in childhood until 13 years of age in a subgroup of the FLORA probiotic intervention cohort. A mixture of four probiotic strains with galacto-oligosaccharides was administrated to the mothers from the 36th week of the pregnancy and later to their infants until 6 months of age. The infants were monitored for the manifestations of atopic eczema, food allergy, allergic rhinitis, and asthma by a pediatrician at 2 and 5 years of age; the allergic status was subsequently verified by a questionnaire at 10 and 13 years of age. The fecal microbiota at 3 months was profiled by 16S rRNA amplicon sequencing targeting the V3-V4 region, with and without adjusting for potentially important early-life factors. Overall, the positive diagnosis for allergic rhinitis between 2 and 13 years was associated with microbiota composition both in non-adjusted and adjusted models. This association was more pronounced in children born to one parent with confirmed atopic diseases compared to those who had two atopic parents and was characterized by a lower relative abundance of Bifidobacterium and Escherichia/Shigella spp. and a higher proportion of Bacteroides. While the probiotic and galacto-oligosaccharides intervention in the entire cohort was previously shown to reduce the prevalence of eczema to a certain extent, no associations were found between the 3-month gut microbiota and childhood eczema in the studied sub-cohort.IMPORTANCEAllergic diseases have increased in prevalence during the past decades globally. Although probiotics have been considered a promising strategy for preventing certain allergy related symptoms, studies connecting the infant gut microbiota and later life allergic morbidity in various populations remain limited. The present study supports an association between the infant microbiota and allergic morbidity after first years of life, which has been rarely examined.CLINICAL TRIALSRegistered at ClinicalTrials.gov (NCT00298337).

Childcare centre soil microbiomes are influenced by substrate type and surrounding vegetation condition

Urban development has profoundly reduced human exposure to biodiverse environments, which is linked to a rise in human disease. The 'biodiversity hypothesis' proposes that contact with diverse microbial communities (microbiota) benefits human health, as exposure to microbial diversity promotes immune training and regulates immune function. Soils and sandpits in urban childcare centres may provide exposure to diverse microbiota that support immunoregulation at a critical developmental stage in a child's life. However, the influence of outdoor substrate (i.e., sand vs. soil) and surrounding vegetation on these environmental microbiota in urban childcare centres remains poorly understood. Here, we used 16S rRNA amplicon sequencing to examine the variation in bacterial communities in sandpits and soils across 22 childcare centres in Adelaide, Australia, plus the impact of plant species richness and habitat condition on these bacterial communities. We show that sandpits had distinct bacterial communities and lower alpha diversity than soils. In addition, we found that plant species richness in the centres' yards and habitat condition surrounding the centres influenced the bacterial communities in soils but not sandpits. These results demonstrate that the diversity and composition of childcare centre sandpit and soil bacterial communities are shaped by substrate type, and that the soils are also shaped by the vegetation within and surrounding the centres. Accordingly, there is potential to modulate the exposure of children to health-associated bacterial communities by managing substrates and vegetation in and around childcare centres.

Determinants of microbiome composition: Insights from free-ranging hybrid zebras (Equus quagga × grevyi)

The composition of mammalian gut microbiomes is highly conserved within species, yet the mechanisms by which microbiome composition is transmitted and maintained within lineages of wild animals remain unclear. Mutually compatible hypotheses exist, including that microbiome fidelity results from inherited dietary habits, shared environmental exposure, morphophysiological filtering and/or maternal effects. Interspecific hybrids are a promising system in which to interrogate the determinants of microbiome composition because hybrids can decouple traits and processes that are otherwise co-inherited in their parent species. We used a population of free-living hybrid zebras (Equus quagga × grevyi) in Kenya to evaluate the roles of these four mechanisms in regulating microbiome composition. We analysed faecal DNA for both the trnL-P6 and the 16S rRNA V4 region to characterize the diets and microbiomes of the hybrid zebra and of their parent species, plains zebra (E. quagga) and Grevy's zebra (E. grevyi). We found that both diet and microbiome composition clustered by species, and that hybrid diets and microbiomes were largely nested within those of the maternal species, plains zebra. Hybrid microbiomes were less variable than those of either parent species where they co-occurred. Diet and microbiome composition were strongly correlated, although the strength of this correlation varied between species. These patterns are most consistent with the maternal-effects hypothesis, somewhat consistent with the diet hypothesis, and largely inconsistent with the environmental-sourcing and morphophysiological-filtering hypotheses. Maternal transmittance likely operates in conjunction with inherited feeding habits to conserve microbiome composition within species.

Current evidence and future perspectives in the exploration of sleep-related eating disorder-a systematic literature review

Sleep-related eating disorder (SRED) is a non-REM parasomnia with potentially significant negative effects on general health (dangerous activities during night eating episodes, obesity, or metabolic syndrome, for example). Although the history of SRED encompasses more than six decades, public awareness and even the awareness of the mental health specialists of this disorder is very limited, a phenomenon that hinders the development of research in this field. Therefore, a systematic review based on PRISMA 2020 guidelines explored the available evidence for SRED found in four electronic databases (PubMed, Cochrane Collaboration, Google Scholar, and Clarivate/Web of Science). A number of 94 primary and secondary reports were retrieved, investigating aspects regarding the risk factors, epidemiology, clinical data and differential diagnosis, epidemiology, structured evaluation, and treatment of SRED. Based on the results of these reports, Z-drugs, but also certain benzodiazepines, antidepressants, antipsychotics, and psychostimulants may trigger the onset of SRED. Psychiatric and neurologic disorders have also been associated with SRED, either as risk factors or comorbid conditions. Cerebral glucose metabolism dysfunctions, neurotransmitter dysfunctions, and genetic factors have been invoked as pathogenetic contributors. Structured assessment of SRED is possible, but there is a dearth of instruments dedicated to this purpose. Data on the prevalence and treatment of SRED exist, but good-quality epidemiological studies and clinical trials are still missing. In conclusion, future research is expected to address the shortcomings of SRED exploration by creating the conditions for better quality and larger group clinical research. The need for such investigation is granted by the importance of this pathology and its negative functional consequences.

IL-10 inhibition during immunization improves vaccine-induced protection against Staphylococcus aureus infection

Staphylococcus aureus is a major human pathogen. An effective anti-S. aureus vaccine remains elusive as the correlates of protection are ill-defined. Targeting specific T cell populations is an important strategy for improving anti-S. aureus vaccine efficacy. Potential bottlenecks that remain are S. aureus-induced immunosuppression and the impact this might have on vaccine-induced immunity. S. aureus induces IL-10, which impedes effector T cell responses, facilitating persistence during both colonization and infection. Thus, it was hypothesized that transient targeting of IL-10 might represent an innovative way to improve vaccine efficacy. In this study, IL-10 expression was elevated in the nares of persistent carriers of S. aureus, and this was associated with reduced systemic S. aureus-specific Th1 responses. This suggests that systemic responses are remodeled because of commensal exposure to S. aureus, which negatively implicates vaccine function. To provide proof of concept that targeting immunosuppressive responses during immunization may be a useful approach to improve vaccine efficacy, we immunized mice with T cell-activating vaccines in combination with IL-10-neutralizing antibodies. Blocking IL-10 during vaccination enhanced effector T cell responses and improved bacterial clearance during subsequent systemic and subcutaneous infection. Taken together, these results reveal a potentially novel strategy for improving anti-S. aureus vaccine efficacy.

Human Breast Milk: The Role of Its Microbiota and Metabolites in Infant Health

This review explores the role of microorganisms and metabolites in human breast milk and their impact on neonatal health. Breast milk serves as both a primary source of nutrition for newborns and contributes to the development and maturation of the digestive, immunological, and neurological systems. It has the potential to reduce the risks of infections, allergies, and asthma. As our understanding of the properties of human milk advances, there is growing interest in incorporating its benefits into personalized infant nutrition strategies, particularly in situations in which breastfeeding is not an option. Future infant formula products are expected to emulate the composition and advantages of human milk, aligning with an evolving understanding of infant nutrition. The long-term health implications of human milk are still under investigation.

Impact of high-altitude acclimatization and de-acclimatization on the intestinal microbiota of rats in a natural high-altitude environment

Introduction

Intestinal microorganisms play an important role in the health of both humans and animals, with their composition being influenced by changes in the host's environment.

Methods

We evaluated the longitudinal changes in the fecal microbial community of rats at different altitudes across various time points. Rats were airlifted to high altitude (3,650 m) and acclimatized for 42 days (HAC), before being by airlifted back to low altitude (500 m) and de-acclimatized for 28 days (HADA); meanwhile, the control group included rats living at low altitude (500 m; LA). We investigated changes in the gut microbiota at 12 time points during high-altitude acclimatization and de-acclimatization, employing 16S rRNA gene sequencing technology alongside physiological indices, such as weight and daily autonomous activity time.

Results

A significant increase in the Chao1 index was observed on day 14 in the HAC and HADA groups compared to that in the LA group, indicating clear differences in species richness. Moreover, the principal coordinate analysis revealed that the bacterial community structures of HAC and HADA differed from those in LA. Long-term high-altitude acclimatization and de- acclimatization resulted in the reduced abundance of the probiotic Lactobacillus. Altitude and age significantly influenced intestinal microbiota composition, with changes in ambient oxygen content and atmospheric partial pressure being considered key causal factors of altitude-dependent alterations in microbiota composition. High-altitude may be linked to an increase in anaerobic bacterial abundance and a decrease in non-anaerobic bacterial abundance.

Discussion

In this study, the hypobaric hypoxic conditions at high-altitude increased the abundance of anaerobes, while reducing the abundance of probiotics; these changes in bacterial community structure may, ultimately, affect host health. Overall, gaining a comprehensive understanding of the intestinal microbiota alterations during high-altitude acclimatization and de-acclimatization is essential for the development of effective prevention and treatment strategies to better protect the health of individuals traveling between high- and low-altitude areas.

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.

A Stress Reduction Intervention for Lactating Mothers Alters Maternal Gut, Breast Milk, and Infant Gut Microbiomes: Data from a Randomized Controlled Trial

BACKGROUND

This secondary analysis of data from a randomized controlled trial (RCT) investigated how the maternal gut, breast milk, and infant gut microbiomes may contribute to the effects of a relaxation intervention, which reduced maternal stress and promoted infant weight gain.

METHODS

An RCT was undertaken in healthy Chinese primiparous mother-infant pairs (340/7-376/7gestation weeks). Mothers were randomly allocated to either the intervention group (IG, listening to relaxation meditation) or the control group (CG). Outcomes were the differences in microbiome composition and the diversity in the maternal gut, breast milk, and infant gut at 1 (baseline) and 8 weeks (post-intervention) between IG and CG, assessed using 16S rRNA gene amplicon sequencing of fecal and breastmilk samples.

RESULTS

In total, 38 mother-infant pairs were included in this analysis (IG = 19, CG = 19). The overall microbiome community structure in the maternal gut was significantly different between the IG and CG at 1 week, with the difference being more significant at 8 weeks (Bray-Curtis distance R2 = 0.04 vs. R2 = 0.13). Post-intervention, a significantly lower α-diversity was observed in IG breast milk (observed features: CG = 295 vs. IG = 255, p = 0.032); the Bifidobacterium genera presented a higher relative abundance. A significantly higher α-diversity was observed in IG infant gut (observed features: CG = 73 vs. IG = 113, p < 0.001).

CONCLUSIONS

The findings were consistent with the hypothesis that the microbiome might mediate observed relaxation intervention effects via gut-brain axis and entero-mammary pathways; but confirmation is required.

Human Milk Components and the Infant Gut Microbiome at 6 Months: Understanding the Interconnected Relationship

BACKGROUND

Human milk oligosaccharides have been shown to relate to the infant gut microbiome. However, the impact of other human milk components on infant gut bacterial colonization remains unexplored.

OBJECTIVES

Our cross-sectional analysis aimed to investigate associations between human milk components (energy, macronutrients, free amino acids, inflammatory markers, and hormones) and infant gut microbiome diversity and composition (phylum, family, and genus) at 6 mo of age.

METHODS

Human milk and infant stool samples were collected at 6 mo postpartum. The infant gut microbiome was profiled using 16S rRNA sequencing. Linear regression models were performed to examine associations, adjusting for pregravid BMI (kg/m2), delivery mode, duration of human milk feeding, and infant sex, with q < 0.2 considered significant.

RESULTS

This analysis included a total of 54 mothers (100% exclusively feeding human milk) and infants (n = 28 male; 51.9%). Total energy in human milk showed a negative association with α-diversity measures (Chao1 and Shannon). Interleukin (IL)-8 in human milk was positively associated with Chao1 and observed operational taxonomic units. At the family level, human milk glutamine and serine levels showed a negative association with the abundance of Veillonellaceae, whereas isoleucine showed a positive association with Bacteroidaceae. Human milk IL-8 and IL-6 concentrations were positively associated with Bacteroidaceae abundance. IL-8 also had a positive relationship with Bifidobacteriaceae, whereas it had a negative relationship with Streptococcacea and Clostridiaceae. Human milk IL-8 was positively associated with the phylum Bacteroidetes, and negatively associated with Proteobacteria. At the genus level, human milk IL-8 exhibited a positive relationship with Bacteroides, whereas human milk isoleucine had a negative relationship with Bacteroides and Ruminococcus. Pregravid BMI and sex effects were observed.

CONCLUSIONS

IL-8 in human milk could potentially prepare the infant's immune system to respond effectively to various microorganisms, potentially promoting the growth of beneficial gut bacteria and protecting against pathogens.

Protective effects of Lactobacillus on heat stress-induced intestinal injury in finisher broilers by regulating gut microbiota and stimulating epithelial development

Heat stress (HS) is a critical challenge in broilers due to the high metabolic rate and lack of sweat glands. Results from this study show that implementing a cyclic chronic HS (34 °C for 7 h/d) to finisher broilers decreased the diversity of cecal microbiota and impaired intestinal barrier, resulting in gut leak and decreased body weight (both P < 0.05). These alterations might be related to inflammatory outbursts and the retarded proliferation of intestinal epithelial cells (IECs) according to the transcriptome analysis. Considering the potential beneficial properties of Lactobacillus on intestinal development and function, the protective effects of Lactobacillus rhamnosus (L. rhamnosus) on the intestine were investigated under HS conditions in this study. Orally supplemented L. rhamnosus improved the composition of cecal microbiota and upregulated the transcription of tight junction proteins in both duodenum and jejunum, with a consequent suppression in intestinal gene expressions of pro-inflammatory cytokines and facilitation in digestive capability. Meanwhile, the jejunal villus height of the birds that received L. rhamnosus was significantly higher compared with those treated with the broth (P < 0.05). The expression abundances of genes related to IECs proliferation and differentiation were increased by L. rhamnosus, along with upregulated mRNA levels of Wnt3a and β-catenin in jejunum. In addition, L. rhamnosus attenuated enterocyte apoptosis as indicated by decreased caspase-3 and caspase-9 gene expressions. The results indicated that oral administration with L. rhamnosus mitigated HS-induced dysfunction by promoting intestinal development and epithelial maturation in broilers and that the effects of L. rhamnosus might be dependent of Wnt/β-catenin signaling.

Functional contribution of the intestinal microbiome in autism spectrum disorder, attention deficit hyperactivity disorder, and Rett syndrome: a systematic review of pediatric and adult studies

Introduction

Critical phases of neurodevelopment and gut microbiota diversification occur in early life and both processes are impacted by genetic and environmental factors. Recent studies have shown the presence of gut microbiota alterations in neurodevelopmental disorders. Here we performed a systematic review of alterations of the intestinal microbiota composition and function in pediatric and adult patients affected by autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and Rett syndrome (RETT).

Methods

We searched selected keywords in the online databases of PubMed, Cochrane, and OVID (January 1980 to December 2021) with secondary review of references of eligible articles. Two reviewers independently performed critical appraisals on the included articles using the Critical Appraisal Skills Program for each study design.

Results

Our systematic review identified 18, 7, and 3 original articles describing intestinal microbiota profiles in ASD, ADHD, and RETT, respectively. Decreased Firmicutes and increased Bacteroidetes were observed in the gut microbiota of individuals affected by ASD and ADHD. Proinflammatory cytokines, short-chain fatty acids and neurotransmitter levels were altered in ASD and RETT. Constipation and visceral pain were related to changes in the gut microbiota in patients affected by ASD and RETT. Hyperactivity and impulsivity were negatively correlated with Faecalibacterium (phylum Firmicutes) and positively correlated with Bacteroides sp. (phylum Bacteroidetes) in ADHD subjects. Five studies explored microbiota-or diet-targeted interventions in ASD and ADHD. Probiotic treatments with Lactobacillus sp. and fecal microbiota transplantation from healthy donors reduced constipation and ameliorated ASD symptoms in affected children. Perinatal administration of Lactobacillus sp. prevented the onset of Asperger and ADHD symptoms in adolescence. Micronutrient supplementation improved disease symptomatology in ADHD without causing significant changes in microbiota communities' composition.

Discussion

Several discrepancies were found among the included studies, primarily due to sample size, variations in dietary practices, and a high prevalence of functional gastrointestinal symptoms. Further studies employing longitudinal study designs, larger sample sizes and multi-omics technologies are warranted to identify the functional contribution of the intestinal microbiota in developmental trajectories of the human brain and neurobehavior.

Systematic review registration

https://clinicaltrials.gov/, CRD42020158734.

Unraveling the complexity of Disorders of the Gut-Brain Interaction: the gut microbiota connection in children

"Disorders of Gut-Brain Interaction (DGBIs)," formerly referred to as "Functional Gastrointestinal Disorders (FGIDs)," encompass a prevalent array of chronic or recurring gastrointestinal symptoms that notably impact the quality of life for affected children and their families. Recent studies have elucidated the intricate pathophysiology of DGBIs, underscoring their correlation with gut microbiota. This review seeks to explore the present comprehension of the gut microbiota's role in DGBI development. While other factors can contribute to DGBIs, the gut microbiota prominently influences the onset and progression of these conditions. According to the Rome IV diagnostic criteria, DGBI prevalence is approximately 40% worldwide. The Rome Foundation has diligently worked for nearly three decades to refine our comprehension of DGBIs. By centering on the gut microbiota, this review sheds light on potential therapeutic interventions for DGBIs, potentially enhancing the quality of life for pediatric patients and their families.

A common trajectory of gut microbiome development during the first month in healthy neonates with limited inter-individual environmental variations

The early development of the gut microbiome is governed by multiple factors and has significantly long-term effects on later-in-life health. To minimize inter-individual variations in the environment, we determined developmental trajectories of the gut microbiome in 28 healthy neonates during their stay at a postpartum center. Stool samples were collected at three time points: the first-pass meconium within 24 h of life, and at 7 and 28 days of age. Illumina sequencing of the V3-V4 region of 16S rRNA was used to investigate microbiota profiles. We found that there was a distinct microbiota structure at each time point, with a significant shift during the first week. Proteobacteria was most abundant in the first-pass meconium; Firmicutes and Actinobacteria increased with age and were substituted as the major components. Except for a short-term influence of different delivery modes on the microbiota composition, early microbiome development was not remarkably affected by gravidity, maternal intrapartum antibiotic treatment, premature rupture of membranes, or postnatal phototherapy. Hence, our data showed a similar developmental trajectory of the gut microbiome during the first month in healthy neonates when limited in environmental variations. Environmental factors external to the host were crucial in the early microbiome development.

Association of Long-Term Habitual Dietary Fiber Intake since Infancy with Gut Microbiota Composition in Young Adulthood

BACKGROUND

Dietary fiber is an important health-promoting component of the diet, which is fermented by the gut microbes that produce metabolites beneficial for the host's health.

OBJECTIVES

We studied the associations of habitual long-term fiber intake from infancy with gut microbiota composition in young adulthood by leveraging data from the Special Turku Coronary Risk Factor Intervention Project, an infancy-onset 20-y dietary counseling study.

METHODS

Fiber intake was assessed annually using food diaries from infancy ≤ age 20 y. At age 26 y, the first postintervention follow-up study was conducted including food diaries and fecal sample collection (N = 357). Cumulative dietary fiber intake was assessed as the area under the curve for energy-adjusted fiber intake throughout the study (age 0-26 y). Gut microbiota was profiled using 16S ribosomal ribonucleic acid amplicon sequencing. The primary outcomes were 1) α diversity expressed as the observed richness and Shannon index, 2) β diversity using Bray-Curtis dissimilarity scores, and 3) differential abundance of each microbial taxa with respect to the cumulative energy-adjusted dietary fiber intake.

RESULTS

Higher cumulative dietary fiber intake was associated with decreased Shannon index (β = -0.019 per unit change in cumulative fiber intake, P = 0.008). Overall microbial community composition was related to the amount of fiber consumed (permutational analysis of variation R2 = 0.005, P = 0.024). The only genus that was increased with higher cumulative fiber intake was butyrate-producing Butyrivibrio (log2 fold-change per unit change in cumulative fiber intake 0.40, adjusted P = 0.023), whereas some other known butyrate producers such as Faecalibacterium and Subdoligranulum were decreased with higher cumulative fiber intake.

CONCLUSIONS

As early-life nutritional exposures may affect the lifetime microbiota composition and disease risk, this study adds novel information on the associations of long-term dietary fiber intake with the gut microbiota. This trial was registered at clinicaltrials.gov as NCT00223600.

The Role of Diet and Nutritional Interventions for the Infant Gut Microbiome

The infant gut microbiome plays a key role in the healthy development of the human organism and appears to be influenced by dietary practices through multiple pathways. First, maternal diet during pregnancy and infant nutrition significantly influence the infant gut microbiota. Moreover, breastfeeding fosters the proliferation of beneficial bacteria, while formula feeding increases microbial diversity. The timing of introducing solid foods also influences gut microbiota composition. In preterm infants the gut microbiota development is influenced by multiple factors, including the time since birth and the intake of breast milk, and interventions such as probiotics and prebiotics supplementation show promising results in reducing morbidity and mortality in this population. These findings underscore the need for future research to understand the long-term health impacts of these interventions and for further strategies to enrich the gut microbiome of formula-fed and preterm infants.

Chronic Morphine Treatment and Antiretroviral Therapy Exacerbate HIV-Distal Sensory Peripheral Neuropathy and Induce Distinct Microbial Alterations in the HIV Tg26 Mouse Model

Distal Sensory Peripheral Neuropathy (DSP) is a common complication in HIV-infected individuals, leading to chronic pain and reduced quality of life. Even with antiretroviral therapy (ART), DSP persists, often prompting the use of opioid analgesics, which can paradoxically worsen symptoms through opioid-induced microbial dysbiosis. This study employs the HIV Tg26 mouse model to investigate HIV-DSP development and assess gut microbiome changes in response to chronic morphine treatment and ART using 16S rRNA sequencing. Our results reveal that chronic morphine and ART exacerbate HIV-DSP in Tg26 mice, primarily through mechanical pain pathways. As the gut microbiome may be involved in chronic pain persistence, microbiome analysis indicated distinct bacterial community changes between WT and Tg26 mice as well as morphine- and ART-induced microbial changes in the Tg26 mice. This study reveals the Tg26 mouse model to be a relevant system that can help elucidate the pathogenic mechanisms of the opioid- and ART-induced exacerbation of HIV-associated pain. Our results shed light on the intricate interplay between HIV infection, ART, opioid use, and the gut microbiome in chronic pain development. They hold implications for understanding the mechanisms underlying HIV-associated pain and microbial dysbiosis, with potential for future research focused on prevention and treatment strategies.

Effect of Pre-, Pro-, and Synbiotics on Biomarkers of Systemic Inflammation in Children: A Scoping Review

Systemic inflammation plays a central role in many diseases and is, therefore, an important therapeutic target. In a scoping review, we assessed the evidence base for the anti-inflammatory effects of pre-, pro-, and synbiotics in children. Of the 1254 clinical trials published in English in Ovid Medline and Cochrane Library PubMed from January 2003 to September 2022, 29 were included in the review. In six studies of healthy children (n = 1552), one reported that fructo-oligosaccharides added to infant formula significantly reduced pro-inflammatory biomarkers, and one study of a single-strain probiotic reported both anti- and pro-inflammatory effects. No effects were seen in the remaining two single-strain studies, one multi-strain probiotic, and one synbiotic study. In 23 studies of children with diseases (n = 1550), prebiotics were tested in 3, single-strain in 16, multi-strain probiotics in 6, and synbiotics in 2 studies. Significantly reduced inflammatory biomarkers were reported in 7/10 studies of atopic/allergic conditions, 3/5 studies of autoimmune diseases, 1/2 studies of preterm infants, 1 study of overweight/obesity, 2/2 studies of severe illness, and 2/3 studies of other diseases. However, only one or two of several biomarkers were often improved; increased pro-inflammatory biomarkers occurred in five of these studies, and a probiotic increased inflammatory biomarkers in a study of newborns with congenital heart disease. The evidence base for the effects of pre-, pro-, and synbiotics on systemic inflammation in children is weak. Further research is needed to determine if anti-inflammatory effects depend on the specific pre-, pro-, and synbiotic preparations, health status, and biomarkers studied.

Modulating the early-life gut microbiota using pro-, pre-, and synbiotics to improve gut health, child development, and growth

In children exposed to poor hygiene and sanitation, invasion of the gut by pathogenic microbes can result in a subclinical enteropathy termed "environmental enteric dysfunction" (EED) that contributes to undernutrition, growth faltering, and impaired organ development. EED may already be present by age 6-12 weeks; therefore, interventions that can be started early in life, and used alongside breastfeeding, are needed to prevent or ameliorate EED. A healthy gut microbiota is critical for intestinal development and repair, nutrient digestion and absorption, and resisting colonization or overgrowth by pathogens. However, its development can be impaired by several environmental factors. Dietary supplementation with pro-, pre-, or synbiotics may be a pragmatic and safe means of building the resilience of the developing gut microbiota against adverse environmental factors, thereby preventing EED.

An updated overview on the relationship between human gut microbiome dysbiosis and psychiatric and psychological disorders

There is a lot of evidence establishing that nervous system development is related to the composition and functions of the gut microbiome. In addition, the central nervous system (CNS) controls the imbalance of the intestinal microbiota, constituting a bidirectional communication system. At present, various gut-brain crosstalk routes have been described, including immune, endocrine and neural circuits via the vagal pathway. Several empirical data have associated gut microbiota alterations (dysbiosis) with neuropsychiatric diseases, such as Alzheimer's disease, autism and Parkinson's disease, and with other psychological disorders, like anxiety and depression. Fecal microbiota transplantation (FMT) therapy has shown that the gut microbiota can transfer behavioral features to recipient animals, which provides strong evidence to establish a causal-effect relationship. Interventions, based on prebiotics, probiotics or synbiotics, have demonstrated an important influence of microbiota on neurological disorders by the synthesis of neuroactive compounds that interact with the nervous system and by the regulation of inflammatory and endocrine processes. Further research is needed to demonstrate the influence of gut microbiota dysbiosis on psychiatric and psychological disorders, and how microbiota-based interventions may be used as potential therapeutic tools.

Gut microbiota variations in wild yellow baboons (Papio cynocephalus) are associated with sex and habitat disturbance

Although male and female mammals differ in biological traits and functional needs, the contribution of this sexual dimorphism to variations in gut bacteria and fungi (gut microbiota) in relation to habitat type has not been fully examined. To understand whether the combination of sex and habitat affects gut microbiota variation, we analyzed 40 fecal samples of wild yellow baboons (Papio cynocephalus) living in contrasting habitat types (intact, well-protected vs. fragmented, less protected forests) in the Udzungwa Mountains of Tanzania. Sex determination was performed using the marker genes SRY (Sex-determining Region Y) and DDX3X-DDX3Y (DEAD-Box Helicase 3). Samples were attributed to 34 individuals (19 females and 15 males) belonging to five social groups. Combining the results of sex determination with two amplicon sequencing datasets on bacterial (V1-V3 region of the 16S rRNA gene) and fungal (ITS2) gut communities, we found that overall, baboon females had a significantly higher gut bacterial richness compared to males. Beta diversity estimates indicated that bacterial composition was significantly different between males and females, and this was true for individuals from both well- and less protected forests. Our results highlight the combined role of sex and habitat type in shaping variation in gut microbial communities in wild non-human primates.

Long-Term Impact of Childhood Adversity on the Gut Microbiome of Nursing Students

Adverse childhood experiences (ACEs) encompass negative, stressful, and potentially traumatic events during childhood, impacting physical and mental health outcomes in adulthood. Limited studies suggest ACEs can have short-term effects on children's gut microbiomes and adult cognitive performance under stress. Nevertheless, the long-term effects of ACEs experienced during adulthood remain unexplored. Thus, this study aimed to assess the long-term effects of ACEs on the gut microbiota of adult nursing students. We employed a multidimensional approach, combining 16S rRNA sequencing, bioinformatics tools, and machine learning to predict functional capabilities. High-ACE individuals had an increased abundance of Butyricimonas spp. and Prevotella spp. and decreased levels of Clostridiales, and Lachnospira spp. Prevotella abundance correlated negatively with L-glutamate and L-glutamine biosynthesis, potentially impacting intestinal tissue integrity. While nursing students with high ACE reported increased depression, evidence for a direct gut microbiota-depression relationship was inconclusive. High-ACE individuals also experienced a higher prevalence of diarrhea. These findings highlight the long-lasting impact of ACEs on the gut microbiota and its functions in adulthood, particularly among nursing students. Further research is warranted to develop targeted interventions and strategies for healthcare professionals, optimizing overall health outcomes.

Screening competition and cross-feeding interactions during utilization of human milk oligosaccharides by gut microbes

Background: The infant gut microbiome is a complex community that influences short- and long-term health. Its assembly and composition are governed by variables such as the feeding type. Breast milk provides infants an important supply of human milk oligosaccharides (HMO), a broad family of carbohydrates comprising neutral, fucosylated, and sialylated molecules. There is a positive association between HMOs and the overrepresentation of Bifidobacterium species in the infant gut, which is sustained by multiple molecular determinants present in the genomes of these species. Infant-gut-associated Bifidobacterium species usually share a similar niche and display similar HMO inclinations, suggesting they compete for these resources. There is also strong evidence of cross-feeding interactions between HMO-derived molecules and bifidobacteria. Methods: In this study, we screened for unidirectional and bidirectional interactions between Bifidobacterium and other species using individual HMO. Bifidobacterium bifidum and Bacteroides thetaiotaomicron increased the growth of several other species when their supernatants were used, probably mediated by the partial degradation of HMO. In contrast, Bifidobacterium longum subsp. infantis. supernatants did not exhibit positive growth. Results: Bifidobacterium species compete for lacto-N-tetraose, which is associated with reduced bidirectional growth. The outcome of these interactions was HMO-dependent, in which the two species could compete for one substrate but cross-feed on another. 2'-fucosyllactose and lacto-N-neotetraose are associated with several positive interactions that generally originate from the partial degradation of these HMOs. Conclusion: This study presents evidence for complex interactions during HMO utilization, which can be cooperative or competitive, depending on the nature of the HMO. This information could be useful for understanding how breast milk supports the growth of some Bifidobacterium species, shaping the ecology of this important microbial community.

Shaping Microbiota During the First 1000 Days of Life

Given that the host-microbe interaction is shaped by the immune system response, it is important to understand the key immune system-microbiota relationship during the period from conception to the first years of life. The present work summarizes the available evidence concerning human reproductive microbiota, and also, the microbial colonization during early life, focusing on the potential impact on infant development and health outcomes. Furthermore, we conclude that some dietary strategies including specific probiotics and other-biotics could become potentially valuable tools to modulate the maternal-neonatal microbiota during this early critical window of opportunity for targeted health outcomes throughout the entire lifespan.

Fecal fermentation behavior and immunomodulatory activity of arabinoxylan from wheat bran

Arabinoxylan (AX) is the predominant non-starch polysaccharide in wheat bran, known for its significant immunomodulatory activity. However, existing literature lacks comprehensive studies on AX fermentation by gut microbiota and its subsequent immunomodulatory mechanisms. In the present study, we aimed to investigate the effects of AX on the composition of gut microbiota and the characteristics of its immunomodulatory activity. For this purpose, an in vitro fermentation system and a cyclophosphamide-induced immunosuppressed mouse model were established to explore both the in vitro and in vivo effects of AX on gut microbiota and immune modulation. The results demonstrated that AX was metabolized by gut microbes and in turn to promoting the production of short-chain fatty acids (SCFAs), which concurrently led to a significant decrease in pH. Furthermore, AX treatment significantly changed the microbial composition, elevated the relative abundance of Actinobacteria while reducing that of Bacteroidetes. In the immunosuppressed mice, AX administration improved the thymus and spleen indices, mitigated spleen injury, and bolstered overall immunity. Moreover, AX altered the gut microbiota structure, increasing the abundance of Bacteroidetes and decreasing that of Firmicutes. These findings suggest that wheat bran-derived AX can modulate intestinal microbial composition, improve gut microecology, and enhance host immunity by targeting gut microbiota.

Histamine H4 receptor and TRPV1 mediate itch induced by cadaverine, a metabolite of the microbiome

Cadaverine is an endogenous metabolite produced by the gut microbiome with various activity in physiological and pathological conditions. However, whether cadaverine regulates pain or itch remains unclear. In this study, we first found that cadaverine may bind to histamine 4 receptor (H4R) with higher docking energy score using molecular docking simulations, suggesting cadaverine may act as an endogenous ligand for H4R. We subsequently found intradermal injection of cadaverine into the nape or cheek of mice induces a dose-dependent scratching response in mice, which was suppressed by a selective H4R antagonist JNJ-7777120, transient receptor potential vanilloid 1 (TRPV1) antagonist capsazepine and PLC inhibitor U73122, but not H1R antagonist or TRPA1 antagonist or TRPV4 antagonist. Consistently, cadaverine-induced itch was abolished in Trpv1-/- but not Trpa1-/- mice. Pharmacological analysis indicated that mast cells and opioid receptors were also involved in cadaverine-induced itch in mice. scRNA-Seq data analysis showed that H4R and TRPV1 are mainly co-expressed on NP2, NP3 and PEP1 DRG neurons. Calcium imaging analysis showed that cadaverine perfusion enhanced calcium influx in the dissociated dorsal root ganglion (DRG) neurons, which was suppressed by JNJ-7777120 and capsazepine, as well as in the DRG neurons from Trpv1-/- mice. Patch-clamp recordings found that cadaverine perfusion significantly increased the excitability of small diameter DRG neurons, and JNJ-7777120 abolished this effect, indicating involvement of H4R. Together, these results provide evidences that cadaverine is a novel endogenous pruritogens, which activates H4R/TRPV1 signaling pathways in the primary sensory neurons.

Postbiotics: Functional Food Materials and Therapeutic Agents for Cancer, Diabetes, and Inflammatory Diseases

Postbiotics are (i) "soluble factors secreted by live bacteria, or released after bacterial lysis, such as enzymes, peptides, teichoic acids, peptidoglycan-derived muropeptides, polysaccharides, cell-surface proteins and organic acids"; (ii) "non-viable metabolites produced by microorganisms that exert biological effects on the hosts"; and (iii) "compounds produced by microorganisms, released from food components or microbial constituents, including non-viable cells that, when administered in adequate amounts, promote health and wellbeing". A probiotic- and prebiotic-rich diet ensures an adequate supply of these vital nutrients. During the anaerobic fermentation of organic nutrients, such as prebiotics, postbiotics act as a benevolent bioactive molecule matrix. Postbiotics can be used as functional components in the food industry by offering a number of advantages, such as being added to foods that are harmful to probiotic survival. Postbiotic supplements have grown in popularity in the food, cosmetic, and healthcare industries because of their numerous health advantages. Their classification depends on various factors, including the type of microorganism, structural composition, and physiological functions. This review offers a succinct introduction to postbiotics while discussing their salient features and classification, production, purification, characterization, biological functions, and applications in the food industry. Furthermore, their therapeutic mechanisms as antibacterial, antiviral, antioxidant, anticancer, anti-diabetic, and anti-inflammatory agents are elucidated.

Footprint analysis of CO2 in microbial community succession of raw milk and assessment of its quality

With the growing production of raw milk, interest has been increasing in its quality control. CO2, as a cold processing additive, has been studied to extend the cold storage period and improve the quality of raw milk. However, it is yet uncertain how representative microbial species and biomarkers can succeed one another at distinct critical periods during refrigeration. Therefore, the effects of CO2 treatment on the succession footprint of the microbial community and changes in quality during the period of raw milk chilling were examined by 16S rRNA analysis combined with electronic nose, and electronic tongue techniques. The results indicated that, the refrigeration time was shown to be prolonged by CO2 in a concentration-dependent way. And CO2 treatment was linked to substantial variations in beta and alpha diversity as well as the relative abundances of various microbial taxa (p < 0.01). The dominant bacterial phylum Proteobacteria was replaced with Firmicutes, while the major bacterial genera Acinetobacter and Pseudomonas were replaced with lactic acid bacteria (LAB), including Leuconostoc, Lactococcus, and Lactobacillus. From the perspective of biomarkers enriched in CO2-treated sample, almost all of them belong to LAB, no introduction of harmful toxins has been found. The assessment of the quality of raw milk revealed that CO2 improved the quality of raw milk by lowering the acidity and the rate of protein and fat breakdown, and improved the flavor by reducing the generation of volatiles, and increasing umami, richness, milk flavor and sweetness, but reducing sourness. These findings offer a new theoretical foundation for the industrial use of CO2 in raw milk.

Early life gut microbiome in children following spontaneous preterm birth and maternal preeclampsia

The early life microbiome plays an important role in developmental and long-term health outcomes. However, it is unknown whether adverse pregnancy complications affect the offspring's gut microbiome postnatally and in early years. In a longitudinal cohort with a five-year follow-up of mother-child pairs affected by preeclampsia (PE) or spontaneous preterm birth (sPTB), we evaluated offspring gut alpha and beta diversity as well as taxa abundances considering factors like breastfeeding and mode of delivery. Our study highlights a trend where microbiome diversity exhibits comparable development across adverse and normal pregnancies. However, specific taxa at genus level emerge with distinctive abundances, showing enrichment and/or depletion over time in relation to PE or sPTB. These findings underscore the potential for certain adverse pregnancy complications to induce alterations in the offspring's microbiome over the course of early life. The implications of these findings on the immediate and long-term health of offspring should be investigated in future studies.

Modelling inactivation kinetics of free and encapsulated probiotic cells in millet biscuit under different baking conditions

The rising popularity of probiotic food in the diet for improved health benefits leads to the development of new probiotic functional foods. In general, biscuit is a long-shelf-life snack product that can be consumed straight from the pack without further processing. Although the development of probiotic bakery products is an innovative approach to market expansion, the infusion of probiotics in biscuits to produce probiotic biscuits has not been explored because of the complexity of the baking process. Therefore, this study aimed to evaluate the impact of baking conditions (160, 180, 200, and 220 °C) on the viability of free and encapsulated probiotic Lactobacillus acidophilus NCDC 016 cells by adding them into biscuit dough separately and baking for up to 600 sec. The cells were encapsulated using 20 % maltodextrin and 8.51 % gum arabic as a wall material and spray drying at an inlet and outlet air temperature of 150 and 55 ± 2 °C, respectively. At different baking temperatures (160, 180, 200, and 220 °C), the viability of probiotic (free and encapsulated) cells, the physicochemical properties of biscuits, and the inactivation kinetics of cells were examined by withdrawing samples every 120 sec. The survivability of encapsulated cells was observed to be higher than free cells at 160 and 180 °C for 600 sec. The moisture content and water activity were found to be higher and lower, respectively for encapsulated probiotic biscuits than for the biscuit containing free cells. The observed results of higher cell viability at 200 °C, 360 sec (5.38 log CFU/g) than at 180 °C, 600 sec (5.02 log CFU/g) can be explained by the time-temperature combination. Thus, producing the probiotic biscuit at baking conditions of 200 °C and 360 min is possible, providing the cell viability of 5 log CFU/g of probiotic biscuit. Further, the inactivation kinetics of cells were predicted by log-linear, Weibull, log-logistic, Gompertz, and Buchanan models. Under all baking conditions, the log-linear model was the best model for describing the data of encapsulated and free cells.

The edible plant microbiome: evidence for the occurrence of fruit and vegetable bacteria in the human gut

Diversity of the gut microbiota is crucial for human health. However, whether fruit and vegetable associated bacteria contribute to overall gut bacterial diversity is still unknown. We reconstructed metagenome-assembled genomes from 156 fruit and vegetable metagenomes to investigate the prevalence of associated bacteria in 2,426 publicly available gut metagenomes. The microbiomes of fresh fruits and vegetables and the human gut are represented by members in common such as Enterobacterales, Burkholderiales, and Lactobacillales. Exposure to bacteria via fruit and vegetable consumption potentially has a beneficial impact on the functional diversity of gut microbiota particularly due to the presence of putative health-promoting genes for the production of vitamin and short-chain fatty acids. In the human gut, they were consistently present, although at a low abundance, approx. 2.2%. Host age, vegetable consumption frequency, and the diversity of plants consumed were drivers favoring a higher proportion. Overall, these results provide one of the primary links between the human microbiome and the environmental microbiome. This study revealed evidence that fruit and vegetable-derived microbes could be found in the human gut and contribute to gut microbiome diversity.

Factors affecting the early establishment of neonatal intestinal flora and its intervention measures

In recent years, it has become evident that early-life intestinal flora plays a pivotal role in determining human health. Consequently, it is imperative to explore the establishment of neonatal intestinal flora and its influencing factors. Early neonatal intestinal flora is influenced by a multitude of factors, including maternal and infant-related factors, as well as external environment. This review summarizes the colonization mechanism of intestinal flora in the early life of newborns and discussed their influence on the establishment of neonatal intestinal flora, taking into account factors such as delivery mode, gestational age and feeding mode. Additionally, this review delves into the natural or artificial reconstruction of intestinal flora colonization defects in infants born via cesarean section and premature infants, with the goal of establishing a theoretical foundation for preventing and treating issues related to neonatal intestinal flora colonization and associated diseases.