Development Of Microbiome Research Articles

Discovery of Lacto-N-Biosidases and a Novel N-Acetyllactosaminidase Activity in the CAZy Family GH20: Functional Diversity and Structural Insights.

The glycoside hydrolase family 20 (GH20) predominantly features N-acetylhexosaminidases (EC 3.2.1.52), with only few known lacto-N-biosidases (EC 3.2.1.140; LNBases). LNBases catalyze the degradation of lacto-N-tetraose (LNT), a prominent component of human milk oligosaccharides, thereby supporting a healthy infant gut microbiome development. We investigated GH20 diversity to discover novel enzymes that release disaccharides such as lacto-N-biose (LNB). Our approach combined peptide clustering, sequence analysis, and 3D structure model evaluation to assess active site topologies, focusing on the presence of a subsite -2. Five LNBases were active on pNP-LNB and four showed activity on LNT. One enzyme displayed activity on both pNP-LacNAc and pNP-LNB, establishing the first report of N-acetyllactosaminidase (LacNAcase) activity. Exploration of this enzyme cluster led to the identification of four additional enzymes sharing this dual substrate specificity. Comparing the determined crystal structure of a specific LNBase (TrpyGH20) and the first crystal structure of an enzyme with dual LacNAcase/LNBase activity (TrdeGH20) revealed a highly conserved subsite -1, common to GH20 enzymes, while the -2 subsites varied significantly. TrdeGH20 had a wider subsite -2, accommodating Gal with both β1,4- and β1,3-linkages to the GlcNAc in subsite -1. Biotechnological applications of these enzymes may include structural elucidation of complex carbohydrates and glycoengineering.

Microbiome Evolution of Brewer’s Spent Grain and Spent Coffee Ground Solid Sidestreams Under Industrial Storage Conditions

Brewer’s spent grain (BSG) and spent coffee ground (SCG) are solid sidestreams from beverage production increasingly being upcycled into food, feed and other value-added products. These solid sidestreams are prone to microbial spoilage, negatively impacting their upcycling potential. Three samples each of BSG and SCG were obtained from generators and recycling facilities in Singapore, and their chemical, elemental, and microbial composition was characterized. The spoilage mechanisms were investigated during storage under anaerobic and aerobic conditions. Bacterial loads of sidestreams were low from craft brewery and café sources (<1 and 3.53 ± 0.03 log10 CFU/g) and high from recycling facilities (>6 log10 CFU/g). The microbiome of BSG from recycling facilities was dominated by Bacilli, and B. coagulans was identified as the most prevalent species. SCG from recycling facilities was dominated by lactic acid bacteria, with L. panis being the most prevalent species. Storage up to 14 days under anaerobic conditions led to further bacterial proliferation mainly by Bacilli, lactic acid bacteria, and acetic acid bacteria, while aerobic storage led to extensive fungal contamination, including potential aflatoxin-producing Aspergillus flavus. The results shed light on the spoilage mechanisms, while highlighting the short shelf-life and food safety risks of BSG and SCG to inform valorization strategies.

Programming rumen microbiome development in calves with the anti-methanogenic compound 3-NOP

The aim of this study was to establish a distinctive rumen microbial and fermentation profile using the anti-methanogenic compound 3-NOP to assess dam effect, and nutritional intervention of the juvenile offspring on microbial structure and function of rumen up to 12 months of age, once the treatment was withdrawn. Forty-eight pregnant heifers (H) and their future offspring (C) were allocated to either Control (-) or 3-NOP (+) treatment resulting in four experimental groups: H+/C+, H+/C-, H-/C + and H-/C-. Animals were treated from 6 weeks prior to calving until weaning, with the offspring monitored until 12 months of age. Rumen fluid samples and methane measurements using the Greenfeed system were collected during the trial. Results supported the mode of action of the compound, with a shift in fermentation from acetate to propionate, increases in branched chain fatty acids and formic acid in the 3-NOP treated animals. Similar shifts in microbial populations occurred in 3-NOP treated animals with lower abundances of rumen methanogen populations, increases of bacterial groups Succiniclasticum spp, Candidatus Saccharimonas. Fibrobacter and the families Prevotellaceae and Succinivibrioacea. and the protozoa Entodinium. Early life intervention had an enduring impact on the rumen microbial structure of young animals up to 28 weeks post weaning, however the effect was diminished once 3-NOP was withdrawn. Interestingly, a group of young animals emitted significantly less methane (15%) than the animals that did not receive the treatment during their juvenile stage. Our results suggest a higher resemblance of the young calf microbiome to a low methane adult and that early life colonisation of the rumen persists through to later life with the pre-weaning microbiome comprising ~ 65% of the yearling animal. Further research needs to be performed to determine the timing and dose of 3-NOP for new-born calves that can sustain a reduction in methane emissions after the treatment is withdrawn, under extensive grazing or controlled conditions.

Reduce, reinforce, and replenish: safeguarding the early-life microbiota to reduce intergenerational health disparities

Socioeconomic (SE) disparity and health inequity are closely intertwined and associated with cross-generational increases in the rates of multiple chronic non-communicable diseases (NCDs) in North America and beyond. Coinciding with this social trend is an observed loss of biodiversity within the community of colonizing microbes that live in and on our bodies. Researchers have rightfully pointed to the microbiota as a key modifiable factor with the potential to ease existing health inequities. Although a number of studies have connected the adult microbiome to socioeconomic determinants and health outcomes, few studies have investigated the role of the infant microbiome in perpetuating these outcomes across generations. It is an essential and important question as the infant microbiota is highly sensitive to external forces, and observed shifts during this critical window often portend long-term outcomes of health and disease. While this is often studied in the context of direct modulators, such as delivery mode, family size, antibiotic exposure, and breastfeeding, many of these factors are tied to underlying socioeconomic and/or cross-generational factors. Exploring cross-generational socioeconomic and health inequities through the lens of the infant microbiome may provide valuable avenues to break these intergenerational cycles. In this review, we will focus on the impact of social inequality in infant microbiome development and discuss the benefits of prioritizing and restoring early-life microbiota maturation for reducing intergenerational health disparities.

Maternal gastrointestinal microbiome shapes gut microbial function and resistome of newborns in a cow-to-calf model

BackgroundThe maternal gut microbiome is the direct and important source of early colonization and development of the neonatal gut microbiome. However, differences in unique and shared features between mothers with different physiological phenotypes and their newborns still lack exhaustive investigation. Here, using a cow-to-calf model, a comprehensive investigation was conducted to elucidate the pattern and characterization of microbial transfer from the maternal source to the offspring.ResultsThe microbiota in the rumen and feces of dairy cows were divided into two clusters via enterotype analysis. The cows from the enterotype distinguished by Prevotella in the rumen had better production performance, whereas no difference was observed in the cows classified by feces enterotype. Furthermore, through a pairwise combination of fecal and ruminal enterotypes, we screened a group of dairy cows with excellent phenotypes. The gastrointestinal microbiomes of cows with different phenotypes and their offspring differed significantly. The rumen was a more important microbial source for meconium than feces. Transmission of beneficial bacteria from mother to offspring was observed. Additionally, the meconium inherits advantageous metabolic functions of the rumen. The resistome features of the rumen, feces, and meconium were consistent, and resistome abundance from cows to calves showed an expanding trend. The interaction between antibiotic-resistance genes and mobile genetic elements from the rumen to meconium was the most remarkable. The diversity of core metabolites from cows to calves was stable and not affected by differences in phenotypes. However, the abundance of specific metabolites varied greatly.ConclusionsOur study demonstrates the microbial taxa, metabolic function, and resistome characteristics of maternal and neonatal microbiomes, and reveals the potential vertical transmission of the microbiome from a cow-to-calf model. These findings provide new insights into the transgenerational transmission pattern of the microbiome.2cueHjjtpyRzwmAWUdZ5oAVideo

Call attention to the reproductive disorders of chronic endometritis

Chronic endometritis (CE) is an important factor leading to decreased endometrial receptivity, infertility, and repeated pregnancy loss; endometrial immune dysfunction, abnormal microbial flora, inflammatory status, and other factors play important roles in the occurrence and development of CE. Meanwhile, these factors are closely related to the pathophysiological mechanisms of common diseases that cause infertility, such as endometriosis, polycystic ovary syndrome, tubal diseases, and endometrial polyps. Through further development of high-quality prospective clinical research, microbiome and immunomics of CE and endometriosis,polycystic ovary syndrome and other diseases, to provide a new therapeutic idea for the treatment of refractory CE. In the course of clinical practice, the effective integration of the diagnosis and treatment principles of CE concomitant diseases in the treatment of CE is expected to provide a new choice for preventing the recurrence of CE.

Upper respiratory microbial communities of healthy populations are shaped by niche and age

BackgroundAlterations in upper respiratory microbiomes have been implicated in shaping host health trajectories, including by limiting mucosal pathogen colonization. However, limited comparative studies of respiratory microbiome development and functioning across age groups have been performed. Herein, we perform shotgun metagenomic sequencing paired with pathogen inhibition assays to elucidate differences in nasal and oral microbiome composition and intermicrobial interactions across healthy 24-month-old infant (n = 229) and adult (n = 100) populations.ResultsWe find that beta diversity of nasal and oral microbiomes varies with age, with nasal microbiomes showing greater population-level variation compared to oral microbiomes. Infant microbiome alpha diversity was significantly lower across nasal samples and higher in oral samples, relative to adults. Accordingly, we demonstrate significant differences in genus- and species-level composition of microbiomes between sites and age groups. Antimicrobial resistome patterns likewise varied across body sites, with oral microbiomes showing higher resistance gene abundance compared to nasal microbiomes. Biosynthetic gene clusters encoding specialized metabolite production were found in higher abundance across infant oral microbiomes, relative to adults. Investigation of pathogen inhibition revealed greater inhibition of gram-negative and gram-positive bacteria by oral commensals, while nasal isolates had higher antifungal activity.ConclusionsIn summary, we identify significant differences in the microbial communities inhabiting nasal and oral cavities of healthy infants relative to adults. These findings inform our understanding of the interactions impacting respiratory microbiome composition and functions related to colonization resistance, with important implications for host health across the lifespan.5XcHcd9N21H4_6hqSTf5-oVideo

Impact of Harvest Method on Development of European Sea Bass Skin Microbiome during Chilled Storage

European sea bass (Dicentrarchus labrax) is one of the most significant species farmed in the Mediterranean, yet a very perishable product. Its quality deteriorates rapidly as a result of three mechanisms: microbial activity, chemical oxidation, and enzymatic degradation. Microbial spoilage is the mechanism that contributes most to the quality deterioration of fresh and non-processed fish. To this end, our study aims to identify for the first time the combined effect of aquatic environment and harvest method on the composition and trajectory at storage at 0 °C of the European sea bass skin microbiome. Sampling was performed in two commercial fish farms in Western (WG) and Central Greece (CG) where fish were harvested using different methods: direct immersion in ice water or a mixture of slurry ice; application of electro-stunning prior to immersion in ice water. Samples were collected on harvest day and one week post-harvest. To profile the bacterial communities in the fish skin, 16S ribosomal RNA gene sequencing was used. The results and the following analyses indicated that the aquatic environment shaped the original composition of the skin microbiome, with 815 ASVs identified in the WG farm as opposed to 362 ASVs in the CG farm. Moreover, Pseudomonas and Pseudoalteromonas dominated the skin microbiome in the WG farm, unlike the CG farm where Shewanella and Psychrobacter were the dominant genera. All these genera contain species such as Shewanella putrefaciens, Pseudomonas aeruginosa, Pseudoalteromonas spp., and Psychrobacter sp., all of which have been implicated in the deterioration and spoilage of the final product. The different harvest methods drove variations in the microbiome already shaped by the aquatic environment, with electro-stunning favoring more diversity in the skin microbiome. The aquatic environment in combination with the harvest method appeared to determine the skin microbiome trajectory at storage at 0 °C. Although Shewanella had dominated the skin microbiome in all samples one week post-harvest, the diversity and the relative abundance of genera were strongly influenced by the aquatic environment and the harvest method. This study sheds light on the hierarchy of the factors shaping the fish skin microbiome and their importance for controlling post-harvest quality of fresh fish.

Multi-omics insights into the energy compensation of rumen microbiota of grazing yaks in cold season.

The ability of yaks to adapt to the extreme environment of low temperatures and hypoxia at cold seasons on the Qinghai-Tibet Plateau (QTP) is related to the host genome; however, the convergent evolution of rumen microbiomes in host adaption is unknown. Here, we conducted a multi-omics study on the rumen fluid of grazing yaks from warm (July) and cold (December) seasons on the QTP to evaluate the convergent evolution of rumen microbiomes in the adaptation of grazing yaks to cold-seasons environments. The results showed that grazing yaks at cold seasons had higher fibrolytic enzyme activities and volatile fatty acids (VFAs) concentrations, and the relative abundance of Firmicutes and the ratio Firmicutes to Bacteroidetes was significantly higher than that of yaks at warm seasons. Macrogenomic analyses showed that genes involved in forming VFAs and arginine were significantly enriched in cold-season yaks. Transcriptome analyses of the rumen epithelium showed that 72 genes associated with VFAs absorption and transport were significantly upregulated in cold-season yaks. Metabolomic analyses showed that the levels of ornithine, related to efficient nitrogen utilization, were significantly upregulated in cold-season yaks. The synergistic role of rumen microbiomes in the adaptation of grazing yaks to extreme environments at cold seasons was revealed by multi-omics study.

Development of an infant colon simulating in vitro model, I-TIM-2, to study the effects of modulation strategies on the infant gut microbiome composition and function.

The early life stages are critical for the development of the gut microbiome. Variables such as antibiotics exposure, birth-mode via Cesarean section, and formula feeding are associated with disruptions in microbiome development and are related to adverse health effects later in life. Studying the effects of microbiome-modulating strategies in infants is challenged by appropriate ethical constraints. Therefore, we developed I-TIM-2, an infant in vitro colonic model based on the validated, computer-controlled, dynamic model of the colon, TIM-2. The system, consisting of four separate compartments, was inoculated with feces from four healthy, primarily breastfed infants, displaying distinctive microbiome profiles. For each infant's fecal sample, a 96-h experiment was performed, with two compartments receiving an infant diet adapted medium and two compartments additionally receiving five human milk oligosaccharides (HMOs) in physiological concentrations and proportions. Bacterial composition was determined by shotgun metagenomics and qPCR. Concentrations of short-chain fatty acids (SCFAs) and HMOs were determined by LC-MS. Microbial diversity and high amounts of inoculum-derived species were preserved in the model throughout each experiment. Microbiome composition and SCFA concentrations were consistent with published data from infants. HMOs strongly modulated the microbiome composition by stimulating relative proportions of Bifidobacterium. This affected the metabolic output and resulted in an increased production of acetic and formic acid, characteristic of bifidobacterial HMO metabolism. In conclusion, these data demonstrate the development of a valid model to study the dynamics and modulations of the infant gut microbiome and metabolome.IMPORTANCEThe infant gut microbiome is intricately linked to the health of its host. This is partly mediated through the bacterial production of metabolites that interact with the host cells. Human milk shapes the establishment of the infant gut microbiome as it contains human milk sugars that select for primarily bifidobacteria. The establishment can be disrupted by modern interventions such as formula feeding. This can alter the microbiome composition and metabolite production profile, which can affect the host. In this article, we set up an infant in vitro colonic model to study microbiome interactions and functions. In this model, we investigated the effects of human milk sugars and their promotion of bifidobacteria at the expense of other bacteria. The model is an ideal system to assess the effects of various modulating strategies on the infant gut microbiome and its interactions with its host.

Preliminary Studies on the Effect of Soil Conditioner (AMP) Application on the Chemical and Microbiological Properties of Soil under Winter Oilseed Rape Cultivation

This study analyzed the effect of the application of a soil conditioner under the trade name of the Agro Mineral Product (AMP) in the winter rapeseed cultivation on the bacterial and fungal abundance, ion concentrations, and electrolytic conductivity of the soil solution. It was demonstrated that the AMP influenced changes in the total abundance of the culturable fractions of the soil bacteria and fungi at each of the tested time points. A stimulatory effect of the preparation on the growth of the soil bacteria and an inhibitory effect on the development of the fungi was observed, particularly at doses of 4 and 8 t·ha−1. A dose of 12 t·ha−1 proved to be the least effective in relation to the development of the soil microbiome. Increasing the AMP fertilization dose above 4 t·ha−1 caused changes in the chemistry of the soil solution (pH, EC, HCO3−, K+, and PO4-P). It is worth noting that this primarily resulted in decreases in the amounts of mobile forms of potassium (from 40.4 mg·dm−3 in the control to 26.7 mg·dm−3 at the 8 t·ha−1 dose) and orthophosphate as phosphorus (from −6.00 mg·dm−3 in the control to 3.75 mg·dm−3 at the 8 t·ha−1 dose) in the soil solution, which resulted in a reduction in the yield of the winter rapeseed (from 4.76 t·ha−1 in the control to 4.61 t·ha−1 at the 8 t·ha−1 and 4.43 t·ha−1 at the 12 t·ha−1 AMP dose).

Changes in the intestinal microbiome of the preterm baby associated with stopping non-invasive pressure support: a prospective cohort study

BackgroundIntestinal dysbiosis is implicated in the pathogenesis of necrotising enterocolitis and late-onset sepsis in preterm babies. The provision of non-invasive positive pressure ventilation is a common clinical intervention in preterm...

The importance of gut microbiome in the perinatal period.

The perinatal period is a pivotal phase for the formation and growth of the neonatal microbiome,profoundly impacting long-term health outcomes. •The perinatal period is a critical phase for the development of the neonatal microbiome, with factors such as mode of delivery, maternal diet, antibiotic exposure, and feeding practices influencing its composition and diversity, which has significant implications for long-term health. • The neonatal microbiome plays a vital role in shaping the immune system, metabolism, and neurodevelopment of infants. • Recent studies have highlighted the potential of targeted interventions, such as probiotic and prebiotic supplementation, and innovative practices like maternal vaginal seeding, to optimize microbiome development during the perinatal period. • Emerging evidence suggests that specific bacterial genera and species within the neonatal microbiome are associated with reduced risks of developing chronic conditions, indicating new avenues for promoting long-term health starting from early life.

Clinical relationships between the intratumoral microbiome and risk factors for head and neck cancer

A bioinformatic analysis is a promising approach to understand the relationship between the vast tumor microbiome and cancer development. In the present study, we studied the relationships between the intratumoral microbiome and classical clinical risk factors using bioinformatics analysis of the Cancer Genome Atlas (TCGA) and the Cancer Microbiome Atlas (TCMA) datasets involving HNSCC patients. We used TCMA database and investigated the abundance of microbes at the genus level in solid normal tissue (n=22) and the primary tumors of patients with head and neck squamous cell carcinoma (HNSCC) (n=154) and identified three major tumor microbiomes, Fusobacterium, Prevotella, and Streptococcus. The tissue level of Fusobacterium was higher in primary tumors than in solid normal tissue. However, univariate and multivariate analyses of these 3 microbes showed no significant effects on patient survival. We then extracted 43, 55, or 59 genes that were differentially expressed between the over and under the median groups for Fusobacterium, Prevotella, or Streptococcus using the criteria of >2.5, >1.5, or >2.0 fold and p<0.05 in the Mann-Whitney U-test. The results of a pathway analysis revealed the association of Fusobacterium- and Streptococcus-related genes with the IL-17 signaling pathway and Staphylococcus aureus infection, while Prevotella-associated pathways were not extracted. A protein-protein interaction analysis revealed a dense network in the order of Fusobacterium, Streptococcus, and Prevotella. An investigation of the relationships between the intratumoral microbiome and classical clinical risk factors showed that high levels of Fusobacterium were associated with a good prognosis in the absence of alcohol consumption and smoking, while high levels of Streptococcus were associated with a poor prognosis in the absence of alcohol consumption. In conclusion, intratumoral Fusobacterium and Streptococcus may affect the prognosis of patients with HNSCC, and their effects on HNSCC are modulated by the impact of drinking and smoking.

Influence of the Chemical Properties of Cereal Grains on the Structure and Metabolism of the Bacteriome of Rhyzopertha dominica (F.) and Its Development: A Cause-Effect Analysis.

Rhyzopertha dominica causes significant economic losses in stored cereals. Insects' digestive tract microbiome is crucial for their development, metabolism, resistance, and digestion. This work aimed to test whether the different chemical properties of different wheat and barley grain cultivars cause disturbances in insect foraging and rearrangements of the structure of the R. dominica microbiome. The results indicated that grain cultivars significantly influence the microbiome, metabolism, and insect foraging. Most observed traits and microbiome structures were not correlated at the species level, as confirmed by ANOSIM (p = 0.441). However, the PLS-PM analysis revealed significant patterns within barley cultivars. The study found associations between C18:2 fatty acids, entomopathogenic bacteria, an impaired nitrogen cycle, lysine production of bacterial origin, and insect feeding. The antioxidant effects also showed trends towards impacting the microbiome and insect development. The findings suggest that manipulating grain chemical properties (increasing C18:2 and antioxidant levels) can influence the R. dominica microbiome, disrupting their foraging behaviours and adaptation to storage environments. This research supports the potential for breeding resistant cereals, offering an effective pest control strategy and reducing pesticide use in food production.

Co-existence of two antibiotic-producing marine bacteria: Pseudoalteromonas piscicida reduce gene expression and production of the antibacterial compound, tropodithietic acid, in Phaeobacter sp.

Many bacteria co-exist and produce antibiotics, yet we know little about how they cope and occupy the same niche. The purpose of the present study was to determine if and how two potent antibiotic-producing marine bacteria influence the secondary metabolome of each other. We established an agar- and broth-based system allowing co-existence of a Phaeobacter species and Pseudoalteromonas piscicida that, respectively, produce tropodithietic acid (TDA) and bromoalterochromides (BACs). Co-culturing of Phaeobacter sp. strain A36a-5a on Marine Agar with P. piscicida strain B39bio caused a reduction of TDA production in the Phaeobacter colony. We constructed a transcriptional gene reporter fusion in the tdaC gene in the TDA biosynthetic pathway in Phaeobacter and demonstrated that the reduction of TDA by P. piscicida was due to the suppression of the TDA biosynthesis. A stable liquid co-cultivation system was developed, and the expression of tdaC in Phaeobacter was reduced eightfold lower (per cell) in the co-culture compared to the monoculture. Mass spectrometry imaging of co-cultured colonies revealed a reduction of TDA and indicated that BACs diffused into the Phaeobacter colony. BACs were purified from Pseudoalteromonas; however, when added as pure compounds or a mixture they did not influence TDA production. In co-culture, the metabolome was dominated by Pseudoalteromonas features indicating that production of other Phaeobacter compounds besides TDA was reduced. In conclusion, co-existence of two antibiotic-producing bacteria may be allowed by one causing reduction in the antagonistic potential of the other. The reduction (here of TDA) was not caused by degradation but by a yet uncharacterized mechanism allowing Pseudoalteromonas to reduce expression of the TDA biosynthetic pathway.IMPORTANCEThe drug potential of antimicrobial secondary metabolites has been the main driver of research into these compounds. However, in recent years, their natural role in microbial systems and microbiomes has become important to determine the assembly and development of microbiomes. Herein, we demonstrate that two potent antibiotic-producing bacteria can co-exist, and one mechanism allowing the co-existence is the specific reduction of antibiotic production in one bacterium by the other. Understanding the molecular mechanisms in complex interactions provides insights for applied uses, such as when developing TDA-producing bacteria for use as biocontrol in aquaculture.

The role of Fusobacterium nucleatum in the pathogenesis of colon cancer.

Previously, many studies have reported changes in the gut microbiota of patients with colorectal cancer (CRC). While CRC is a well-described disease, the relationship between its development and features of the intestinal microbiome is still being understood. Evidence linking Fusobacterium nucleatum enrichment in colorectal tumor tissue has prompted the elucidation of various molecular mechanisms and tumor-promoting attributes. In this review we highlight various aspects of our understanding of the relationship between the development of CRC and the alteration of intestinal microbiome, focusing specifically on the role of F. nucleatum. As the amount of F. nucleatum DNA in CRC tissue is associated with shorter survival, it may potentially serve as a prognostic biomarker, and most importantly may open the door for a role in CRC treatment.

Birth and household exposures are associated with changes to skin bacterial communities during infancy

Abstract Microbial exposures during infancy shape the development of the microbiome, the collection of microbes living in and on the body, which in turn directs immune system training. Newborns acquire a substantial quantity of microbes during birth and throughout infancy via exposure to microbes in the physical and social environment. Alterations to early life microbial environments may give rise to mismatches, where environmental, cultural, and behavioral changes that outpace the body’s adaptive responses can lead to adverse health outcomes, particularly those related to microbiome development and immune system regulation. This study explored the development of the skin microbiome among infants born in Chicago, USA. We collected skin swab microbiome samples from 22 mother-infant dyads during the first 48 hours of life and again at six weeks postpartum. Mothers provided information about social environments and hygiene behaviors that may impact infants’ microbial exposures. Analysis of 16S rRNA bacterial gene sequencing data revealed correlations between infant skin bacterial abundance shortly after birth and factors such as antibiotic exposure and receiving a bath in the hospital. The composition of the infant microbiome at six weeks of age was associated with interactions with caregivers and infant feeding practices. We also found shifts in maternal skin microbiomes that may reflect increased hygiene practices in the hospital. Our data suggest that factors related to the birth and household environment can impact the development of infant skin microbiomes and point to practices that may produce mismatches for the infant microbiome and immune system.

Dermatological Health in the Light of Skin Microbiome Evolution.

The complex ecosystem of the skin microbiome is essential for skin health by acting as a primary defense against infections, regulating immune responses, and maintaining barrier integrity. This literature review aims to consolidate existing information on the skin microbiome, focusing on its composition, functionality, importance, and its impact on skin aging. An exhaustive exploration of scholarly literature was performed utilizing electronic databases including PubMed, Google Scholar, and ResearchGate, focusing on studies published between 2011 and 2024. Keywords included "skin microbiome," "skin microbiota," and "aging skin." Studies involving human subjects that focused on the skin microbiome's relationship with skin health were included. Out of 100 initially identified studies, 70 met the inclusion criteria and were reviewed. Studies showed that aging is associated with a reduction in the variety of microorganisms of the skin microbiome, leading to an increased susceptibility to skin conditions. Consequently, this underlines the interest in bacteriotherapy, mainly topical probiotics, to reinforce the skin microbiome in older adults, suggesting improvements in skin health and a reduction in age-related skin conditions. Further exploration is needed into the microbiome's role in skin health and the development of innovative, microbe-based skincare products. Biotherapeutic approaches, including the use of phages, endolysins, probiotics, prebiotics, postbiotics, and microbiome transplantation, can restore balance and enhance skin health. This article also addresses regulatory standards in the EU and the USA that ensure the safety and effectiveness of microbial skincare products. This review underscores the need to advance research on the skin microbiome's role in cosmetic enhancements and tailored skincare solutions, highlighting a great interest in leveraging microbial communities for dermatological benefits.

Gut microbiome and resistome development in foals

Gut microbiome and resistome development in foals