Establishment Of Gut Microbiota Research Articles

Personalized Nutrition with Banked Human Milk for Early Gut Microbiota Development: In Pursuit of the Perfect Match.

The correct initial colonization and establishment of the gut microbiota during the early stages of life is a key step, with long-lasting consequences throughout the entire lifespan of the individual. This process is affected by several perinatal factors; among them, feeding mode is known to have a critical role. Breastfeeding is the optimal nutrition for neonates; however, it is not always possible, especially in cases of prematurity or early pathology. In such cases, most commonly babies are fed with infant formulas in spite of the official nutritional and health international organizations' recommendation on the use of donated human milk through milk banks for these cases. However, donated human milk still does not totally match maternal milk in terms of infant growth and gut microbiota development. The present review summarizes the practices of milk banks and hospitals regarding donated human milk, its safety and quality, and the health outcomes in infants fed with donated human milk. Additionally, we explore different alternatives to customize pasteurized donated human milk with the aim of finding the perfect match between each baby and banked milk for promoting the establishment of a beneficial gut microbiota from the early stages of life.

140 High-resolution characterization of the gut microbiota of neonatal dairy calves using full-length 16S rRNA gene amplicon sequencing

Abstract The gut microbiota has a crucial role in preventing pathogen colonization and training the immune system. An imbalanced gut microbiota tends to induce calf diarrhea, which can lead to dehydration and metabolic acidosis. Therefore, it is urgent to identify critical factors that influence the establishment of gut microbiota in the early stages of development in dairy calves. Most previous research relied on short-read-based partial 16S rRNA gene amplicon sequencing to study calf microbiota, which has limited taxonomic resolution. The aim of our study is to obtain a species-level characterization of calf gut microbiota using long-read based full-length 16S rRNA gene amplicon sequencing and investigate the factors that affect the gut microbiota composition in the early stages of development in dairy calves. We collected fecal samples from the recto-anal junction of 25 Holstein-Angus crossed calves at d 4 and d 14 after birth. The calves were raised in individual outdoor hutches from birth and fed milk replacer twice daily. The gut microbiota was analyzed using full-length 16S rRNA gene amplicon sequencing on an Oxford Nanopore sequencer. The results revealed that the gut microbial diversity measured by Chao 1 (P < 0.001) and Shannon index (P < 0.001) significantly increased from d 4 to d 14. We identified 15 and 36 core bacterial species (prevalence ≥ 80%) in d 4 and d 14 gut microbiota, respectively, and both stages share 7 bacterial species: Bacteroides fragilis, Butyricicoccus pulicaecorum, Enterocloster bolteae, Escherichia coli, Lachnoclostridium sp YL32, Rumiococcus gnavus and Streptococcus equinus. The calf gut microbiota was dominated by Bacteroides fragilis (18%), Escherichia coli (13%), Ruminococcus gnavus (10%) and Butyricicoccus pulicaecorum (6%) species on d 4, and Megamonas rupellensis (18%) and Fusobacterium varium (6%) species (relative abundance > 5%) on d 14. Notably, we found a significant impact of hutch location on the composition of gut microbiota, particularly on d 4, but the impact was reduced on d 14. Moreover, there were 4 dystocia calves among the 25 calves, which had a significantly lower Shannon index (P = 0.046) compared with 4 paired normal calves of similar age and sex, and location balanced. In conclusion, this study provides a species-level resolution of gut microbiota for neonatal dairy calves and indicates a potential impact of dystocia on early microbiota development. Additionally, calf microbiota composition is influenced by environmental factors, likely the soil microbiota where hutches were located, with a more substantial effect on the microbiota at an earlier age.

Maternal-Foetal/Infant Interactions-Gut Microbiota and Immune Health.

In recent years, the number of scientific publications on the role of intestinal microbiota in shaping human health, as well as the occurrence of intestinal dysbiosis in various disease entities, has increased dynamically. However, there is a gap in comprehensively understanding the factors influencing a child's gut microbiota. This review discusses the establishment of gut microbiota and the immunological mechanisms regulating children's microbiota, emphasising the importance of prioritising the development of appropriate gut microbiota in a child from the planning stages of pregnancy. The databases PubMed, Web of Sciences, Cochrane, Scopus and Google Scholar were searched to identify relevant articles. A child's gut microbiota composition is influenced by numerous factors, such as diet during pregnancy, antibiotic therapy, the mother's vaginal microbiota, delivery method, and, later, feeding method and environmental factors. During pregnancy, the foetus naturally acquires bacterial strains from the mother through the placenta, thereby shaping the newborn's immune system. Inappropriate maternal vaginal microbiota may increase the risk of preterm birth. Formula-fed infants typically exhibit a more diverse microbiota than their breastfed counterparts. These factors, among others, shape the maturation of the child's immune system, impacting the production of IgA antibodies that are central to cellular humoral immune defence. Further research should focus on identifying specific microbiota-immune system interactions influencing a child's immune health and developing personalised treatment strategies for immune-related disorders.

An Overview of the Influence of Breastfeeding on the Development of Inflammatory Bowel Disease.

The first 1000 days of life is a critical period that contributes significantly to the programming of an individual's future health. Among the many changes that occur during this period early in life, there is growing evidence that the establishment of healthy gut microbiota plays an important role in the prevention of both short- and long-term health problems. Numerous publications suggest that the quality of the gut microbiota colonisation depends on several dietary factors, including breastfeeding. In this respect, a relationship between breastfeeding and the risk of inflammatory bowel disease (IBD) has been suggested. IBDs are chronic intestinal diseases, and perinatal factors may be partly responsible for their onset. We review the existence of links between breastfeeding and IBD based on experimental and clinical studies. Overall, despite encouraging experimental data in rodents, the association between breastfeeding and the development of IBD remains controversial in humans, partly due to the considerable heterogeneity between clinical studies. The duration of exclusive breastfeeding is probably decisive for its lasting effect on IBD. Thus, specific improvements in our knowledge could support dietary interventions targeting the gut microbiome, such as the early use of prebiotics, probiotics or postbiotics, in order to prevent the disease.

Early-life exposure to the Great Chinese Famine and gut microbiome disruption across adulthood for type 2 diabetes: three population-based cohort studies

BackgroundThe early life stage is critical for the gut microbiota establishment and development. We aimed to investigate the lifelong impact of famine exposure during early life on the adult gut microbial ecosystem and examine the association of famine-induced disturbance in gut microbiota with type 2 diabetes.MethodsWe profiled the gut microbial composition among 11,513 adults (18–97 years) from three independent cohorts and examined the association of famine exposure during early life with alterations of adult gut microbial diversity and composition. We performed co-abundance network analyses to identify keystone taxa in the three cohorts and constructed an index with the shared keystone taxa across the three cohorts. Among each cohort, we used linear regression to examine the association of famine exposure during early life with the keystone taxa index and assessed the correlation between the keystone taxa index and type 2 diabetes using logistic regression adjusted for potential confounders. We combined the effect estimates from the three cohorts using random-effects meta-analysis.ResultsCompared with the no-exposed control group (born during 1962–1964), participants who were exposed to the famine during the first 1000 days of life (born in 1959) had consistently lower gut microbial alpha diversity and alterations in the gut microbial community during adulthood across the three cohorts. Compared with the no-exposed control group, participants who were exposed to famine during the first 1000 days of life were associated with consistently lower levels of keystone taxa index in the three cohorts (pooled beta − 0.29, 95% CI − 0.43, − 0.15). Per 1-standard deviation increment in the keystone taxa index was associated with a 13% lower risk of type 2 diabetes (pooled odds ratio 0.87, 95% CI 0.80, 0.93), with consistent results across three individual cohorts.ConclusionsThese findings reveal a potential role of the gut microbiota in the developmental origins of health and disease (DOHaD) hypothesis, deepening our understanding about the etiology of type 2 diabetes.

Illuminating the Genomic Landscape of Lactiplantibacillus plantarum PU3-A Novel Probiotic Strain Isolated from Human Breast Milk, Explored through Nanopore Sequencing.

Lactiplantibacillus plantarum stands out as a remarkably diverse species of lactic acid bacteria, occupying a myriad of ecological niches. Particularly noteworthy is its presence in human breast milk, which can serve as a reservoir of probiotic bacteria, contributing significantly to the establishment and constitution of infant gut microbiota. In light of this, our study attempted to conduct an initial investigation encompassing both genomic and phenotypic aspects of the L. plantarum PU3 strain, that holds potential as a probiotic agent. By employing the cutting-edge third-generation Nanopore sequencing technology, L. plantarum PU3 revealed a circular chromosome of 3,180,940 bp and nine plasmids of various lengths. The L. plantarum PU3 genome has a total of 2962 protein-coding and non-coding genes. Our in-depth investigations revealed more than 150 probiotic gene markers that unfold the genetic determinants for acid tolerance, bile resistance, adhesion, and oxidative and osmotic stress. The in vivo analysis showed the strain's proficiency in utilizing various carbohydrates as growth substrates, complementing the in silico analysis of the genes involved in metabolic pathways. Notably, the strain demonstrated a pronounced affinity for D-sorbitol, D-mannitol, and D-Gluconic acid, among other carbohydrate sources. The in vitro experimental verification of acid, osmotic and bile tolerance validated the robustness of the strain in challenging environments. Encouragingly, no virulence factors were detected in the genome of PU3, suggesting its safety profile. In search of beneficial properties, we found potential bacteriocin biosynthesis clusters, suggesting its capability for antimicrobial activity. The characteristics exhibited by L. plantarum PU3 pave the way for promising strain potential, warranting further investigations to unlock its full capacity and contributions to probiotic and therapeutic avenues.

Role of gut microbiota in the postnatal thermoregulation of Brandt’s voles

Homeothermy is crucial for mammals. Postnatal growth is the key period for young offspring to acquire gut microbiota. Although gut microbiota may affect mammal thermogenesis, the impact of developmental regulation of gut microbiota on the ability of young pups to produce heat remains unclear. Antibiotics were used to interfere with the establishment of gut microbiota during the development of Brandt's voles, and their thermogenic development and regulatory pathways were determined. Deprivation of microbiota by antibiotics inhibits the development of thermogenesis in pups. Butyric acid and bile acid, as metabolites of gut microbiota, participated in the thermoregulation of pups. We propose that gut microbiota promote the development of thermoregulation through the butyric acid-free fatty acid receptor-2-uncoupling protein-1 or the deoxycholic acid-Takeda-G-protein-receptor-5-uncoupling protein-1 pathway in pups. These results show a relationship between gut microbiota and thermogenesis and expand the mechanism of postnatal development of thermogenesis in small mammals.

A health-promoting role of exclusive breastfeeding on infants through restoring delivery mode-induced gut microbiota perturbations.

The establishment of human gut microbiota in early life is closely associated with both short- and long-term infant health. Delivery mode and feeding pattern are two important determinants of infant gut microbiota. In this longitudinal cohort study, we examined the interplay between the delivery mode and feeding pattern on the dynamics of infant gut microbiota from 6 weeks to 6 months post-delivery in 139 infants. We also assessed the relationship between infant respiratory infection susceptibility and gut microbial changes associated with delivery mode and feeding pattern. At 6 weeks postpartum, the composition and structure of gut microbiota of cesarean section-delivered (CSD) infants differed from those of vaginally delivered (VD) infants, with decreased Bacteroides and Escherichia-Shigella and increased Klebsiella, Veillonella, and Enterococcus. At 6 months postpartum, these delivery mode-induced microbial shifts were restored by exclusive breastfeeding, resulting in similar gut microbial profiles between VD and CSD infants who were exclusively breastfed (P = 0.57) and more variable gut microbial profiles between VD and CSD infants who were mixed fed (P < 0.001). We identified that the VD-associated genera were enriched in healthy infants, while the CSD-associated genera were enriched in infants who suffered from respiratory infections. Our findings indicate that exclusive breastfeeding may play a health-promoting role by reducing infant respiratory infection susceptibility through the restoration of gut microbiota perturbations caused by cesarean section.

A comprehensive review on infant formula: nutritional and functional constituents, recent trends in processing and its impact on infants' gut microbiota.

Human milk is considered the most valuable form of nutrition for infants for their growth, development and function. So far, there are still some cases where feeding human milk is not feasible. As a result, the market for infant formula is widely increasing, and formula feeding become an alternative or substitute for breastfeeding. The nutritional value of the formula can be improved by adding functional bioactive compounds like probiotics, prebiotics, human milk oligosaccharides, vitamins, minerals, taurine, inositol, osteopontin, lactoferrin, gangliosides, carnitine etc. For processing of infant formula, diverse thermal and non-thermal technologies have been employed. Infant formula can be either in powdered form, which requires reconstitution with water or in ready-to-feed liquid form, among which powder form is readily available, shelf-stable and vastly marketed. Infants' gut microbiota is a complex ecosystem and the nutrient composition of infant formula is recognized to have a lasting effect on it. Likewise, the gut microbiota establishment closely parallels with host immune development and growth. Therefore, it must be contemplated as an important factor for consideration while developing formulas. In this review, we have focused on the formulation and manufacturing of safe and nutritious infant formula equivalent to human milk or aligning with the infant's needs and its ultimate impact on infants' gut microbiota.

Prebiotic Supplementation during Lactation Affects Microbial Colonization in Postnatal-Growth-Restricted Mice.

An inadequate perinatal nutritional environment can alter the maturation of the intestinal barrier and promote long-term pathologies such as metabolic syndrome or chronic intestinal diseases. The intestinal microbiota seems to play a determining role in the development of the intestinal barrier. In the present study, we investigated the impact of consuming an early postnatal prebiotic fiber (PF) on growth, intestinal morphology and the microbiota at weaning in postnatal-growth-restricted mice (PNGR). Large litters (15 pups/mother) were generated from FVB/NRj mice to induce PNGR at postnatal day 4 (PN4) and compared to control litters (CTRL, 8 pups/mother). PF (a resistant dextrin) or water was orally administered once daily to the pups from PN8 to PN20 (3.5 g/kg/day). Intestinal morphology was evaluated at weaning (PN21) using the ileum and colon. Microbial colonization and short-chain fatty acid (SCFA) production were investigated using fecal and cecal contents. At weaning, the PNGR mice showed decreased body weight and ileal crypt depth compared to the CTRL. The PNGR microbiota was associated with decreased proportions of the Lachnospiraceae and Oscillospiraceae families and the presence of the Akkermansia family and Enterococcus genus compared to the CTRL pups. The propionate concentrations were also increased with PNGR. While PF supplementation did not impact intestinal morphology in the PNGR pups, the proportions of the Bacteroides and Parabacteroides genera were enriched, but the proportion of the Proteobacteria phylum was reduced. In the CTRL pups, the Akkermansia genus (Verrucomicrobiota phylum) was present in the PF-supplemented CTRL pups compared to the water-supplemented ones. PNGR alters intestinal crypt maturation in the ileum at weaning and gut microbiota colonization. Our data support the notion that PF supplementation might improve gut microbiota establishment during the early postnatal period.

Metagenome-mining indicates an association between bacteriocin presence and strain diversity in the infant gut

BackgroundOur knowledge about the ecological role of bacterial antimicrobial peptides (bacteriocins) in the human gut is limited, particularly in relation to their role in the diversification of the gut microbiota during early life. The aim of this paper was therefore to address associations between bacteriocins and bacterial diversity in the human gut microbiota. To investigate this, we did an extensive screening of 2564 healthy human gut metagenomes for the presence of predicted bacteriocin-encoding genes, comparing bacteriocin gene presence to strain diversity and age.ResultsWe found that the abundance of bacteriocin genes was significantly higher in infant-like metagenomes (< 2 years) compared to adult-like metagenomes (2–107 years). By comparing infant-like metagenomes with and without a given bacteriocin, we found that bacteriocin presence was associated with increased strain diversities.ConclusionsOur findings indicate that bacteriocins may play a role in the strain diversification during the infant gut microbiota establishment.

Associations of maternal antenatal bonding with neonatal meconium microbiota and the behavior temperament of infants: A prospective longitudinal study

Exposure to a poor intrauterine environment, such as maternal prenatal stress, has been linked to gut microbiota health in infants. Understanding the link between maternal prenatal bonding, early gut microbiota, and neuropsychological development may promote healthy development in early life. This study included 306 mother-child pairs. Women were assessed for maternal antenatal bonding using the Maternal Antenatal Attachment Scale in all three trimesters of pregnancy. Neonatal meconium samples were collected after birth. The behavioral temperament of infants was measured using the Very Short Form of the Infant Behavior Questionnaire–Revised at 6 months postpartum. Maternal prenatal bonding was negatively associated with the infants' relative abundance of Burkholderia and was positively associated with the relative abundance of Bifidobacterium, infant surgency and effortful control. The infant's relative abundance of Burkholderia mediates the association between maternal prenatal bonding and effortful control of the infant. This study provides new evidence about the long-term behavioral implications of a prenatally positive intrauterine environment in offspring microbiomes. The integration of maternal bonding assessment and intervention into prenatal healthcare and wellness models may modulate the establishment of gut microbiota in early life and long-term neuropsychological development in infants.

Composition of the intestinal microbiota of infant rhesus macaques at different ages before and after weaning

BackgroundRhesus macaques and humans are closely related genetically and share similar physiological and pathological characteristics. Exploring the impact of diet on the early establishment of gut microbiota in non-human primates can provide relevant clinical models for healthy infant growth and development. At present, few writers have focused on the composition and changes of the intestinal microbes of infant rhesus macaques throughout their progression from birth to formula feeding after weaning. In this study, we used 16S rRNA sequencing technology to explore the composition of the intestinal flora of rhesus macaques at different ages and analyzed the trends in the microbial changes. ResultsThe results showed that the relative abundance of Bifidobacterium and Lactobacillus in the intestinal flora of infant rhesus macaques significantly decreased, and Prevotella increased with age. Bifidobacterium longum and Bifidobacterium breve are effective biomarkers to predict grouping. The metabolic pathways enriched in early life mainly concentrated in glycosphingolipid biosynthesis (lacto and neolacto series) and the degradation and metabolism of alcohols and esters. ConclusionsWe found that age was an important factor that affected the changes in the intestinal flora. This study revealed the change trend of flora in breastfed and formula-fed infant rhesus monkeys in different growth months, and found that the dominant flora changed greatly. This research provides a medically relevant theoretical basis for understanding the healthy development of infants.

DOP24 Early life exposures and risk for inflammatory bowel disease: a nested case-control study in Quebec, Canada

Abstract Background Early childhood is an important period for the establishment of gut microbiota. Most early life risks or protective factors for inflammatory bowel disease are likely to act through an effect on the gut microbiota. The aim of this study was to estimate the associations between exposures in infancy (birth until 3 years of age) such as breastfeeding, antibiotic treatment, presence of domestic pets, and passive smoking, and the occurrence of inflammatory bowel diseases. Methods This case-control study was nested within the Quebec Birth Cohort on Immunity and Health. Cases and controls were identified among persons born in Quebec in 1970-1974 based on their health services from 1983 to 2014 using validated algorithms. All cases and randomly selected controls were invited to participate in a web or telephone questionnaire. Participation rates were 47% among controls (n=946), and respectively 52% (n=1212) and 55% (n=570) among cases of Crohn’s disease and ulcerative colitis. Logistic regression models were used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI), separately for Crohn’s disease and ulcerative colitis. Each exposure was analyzed in a multiple regression model adjusted for relevant covariates identified with a directed acyclic graph. Results Adjusting for perinatal and sociodemographic characteristics, the risk for Crohn’s disease or ulcerative colitis did not differ in subjects who were exclusively breastfed compared to non-breastfed subjects. Partial breastfeeding (breastfeeding combined with infant formula) was not associated with Crohn’s disease (OR=1.03, 95% CI: 0.76-1.40), but an increase in the odds of ulcerative colitis (OR=1.40, 95% CI: 0.99-1.99) was observed as compared with no breastfeeding. Early introduction of solid foods was associated with higher odds of Crohn’s disease (introduction at 3-6 months compared with &amp;gt;6 months: OR=1.35; 95% CI: 1.05-1.78), but not of ulcerative colitis (OR=1.06; 95% CI: 0.77-1.46). Antibiotic use and the presence of domestic pets were not associated with either Crohn’s disease or ulcerative colitis. Passive smoking was associated with increased odds of Crohn’s disease (OR=1.23; 95% CI: 1.00-1.51), but not ulcerative colitis (OR=0.96; 95% CI: 0.75-1.22). Conclusion Differences were noticed in early childhood risk factors for Crohn’s disease and ulcerative colitis. Early introduction of solid foods and passive smoking increased the risk of Crohn’s disease, whereas there was a trend of increased risk of ulcerative colitis with partial as compared with no breastfeeding. The results for partial breastfeeding and early introduction of solid foods are novel and will require further investigation.

Rescue of social deficits by early-life melatonin supplementation through modulation of gut microbiota in a murine model of autism

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with a rapidly increasing global prevalence. Early unstable and immature microbiota are often observed in ASD patients, resulting in neurobehavioral dysfunction. Since the establishment of stable gut microbiota in early life falls into the same critical time window as neurodevelopment, manipulations of the gut microbiota during early life could become a promising strategy for ASD. Melatonin is an endogenous hormone and can restore gut microbial dysbiosis under various disease conditions. Here, we explored the effects of melatonin supplementation during early life on the gut microbiota of the offspring and the subsequent impact on ASD-associated behaviors. Using the valproic acid (VPA) - induced mouse model of autism, we found that melatonin supplementation during late gestation and early postnatal development rescued the social deficits of the offspring. In addition, melatonin restored gut microbial dysbiosis in the VPA-exposed offspring, which was characterized by the significant upregulation of Akkermansia spp. Furthermore, supplementation of Akkermansia spp. alleviated the social deficits induced by VPA exposure via activating the dopaminergic neurons in the ventral tegmental area. These findings discover a novel mechanism underlying the gut microbiota regulation of social behaviors and provide the biological basis for developing gut microbiota-based therapeutics for ASD

Statistical Evaluation of Metaproteomics and 16S rRNA Amplicon Sequencing Techniques for Study of Gut Microbiota Establishment in Infants with Cystic Fibrosis.

Newborn screening for cystic fibrosis (CF) can identify affected but asymptomatic infants. The selection of omic technique for gut microbiota study is crucial due to both the small amount of feces available and the low microorganism load. Our aims were to compare the agreement between 16S rRNA amplicon sequencing and metaproteomics by a robust statistical analysis, including both presence and abundance of taxa, to describe the sequential establishment of the gut microbiota during the first year of life in a small size sample (8 infants and 28 fecal samples). The taxonomic assignations by the two techniques were similar, whereas certain discrepancies were observed in the abundance detection, mostly the lower predicted relative abundance of Bifidobacterium and the higher predicted relative abundance of certain Firmicutes and Proteobacteria by amplicon sequencing. During the first months of life, the CF gut microbiota is characterized by a significant enrichment of Ruminococcus gnavus, the expression of certain virulent bacterial traits, and the detection of human inflammation-related proteins. Metaproteomics provides information on composition and functionality, as well as data on host-microbiome interactions. Its strength is the identification and quantification of Actinobacteria and certain classes of Firmicutes, but alpha diversity indices are not comparable to those of amplicon sequencing. Both techniques detected an aberrant microbiota in our small cohort of infants with CF during their first year of life, dominated by the enrichment of R. gnavus within a human inflammatory environment. IMPORTANCE In recent years, some techniques have been incorporated for the study of microbial ecosystems, being 16S rRNA gene sequencing being the most widely used. Metaproteomics provides the advantage of identifying the interaction between microorganisms and human cells, but the available databases are less extensive as well as imprecise. Few studies compare the statistical differences between the two techniques to define the composition of an ecosystem. Our work shows that the two methods are comparable in terms of microorganism identification but provide different results in alpha diversity analysis. On the other hand, we have studied newborns with cystic fibrosis, for whom we have described the establishment of an intestinal ecosystem marked by the inflammatory response of the host and the enrichment of Ruminococcus gnavus.

Mouse feeding study and microbiome analysis of sourdough bread for evaluation of its health effects.

Sourdough bread fermented with yeast and lactic acid bacteria (LAB) is thought to have various beneficial health effects. However, its beneficial effects were not fully evaluated with in vivo mouse model. To evaluate these effects in vivo, a mouse feeding study and microbiome analysis of white bread containing 40% sourdough (WBS) and yeast-leavened white bread (WB) were performed. Although feed consumption and body weight increased with WBS, the glycemic index was reduced, suggesting a diabetes-lowering effect, probably due to the presence of dietary fiber and short-chain fatty acids (SCFA). In addition, a mineral absorption test showed that WBS increased magnesium absorption owing to phytate degradation during fermentation. Interestingly, WBS decreased total cholesterol and triglycerides, probably due to the dietary fiber and SCFA in LAB. In addition, the ratio of low- and high-density lipoprotein was decreased in WBS, implying potential risk reduction for cardiovascular disease. An immunomodulatory assay of WBS revealed that pro-inflammatory cytokines TNF-α and IL-6 were decreased, suggesting anti-inflammatory activity. Gluten degradation by fermentation and antioxidation activity of menaquinol/ubiquinol by gut microbiota also supported the anti-inflammatory activity of sourdough bread. Furthermore, some beneficial gut bacteria, including Akkermansia, Bifidobacterium, and Lactobacillus, were increased in WBS. In particular, Akkermansia has been associated with anti-inflammatory properties. Consequently, WBS has beneficial effects on health, including decreased glycemic index and cholesterol, increased mineral availability and absorption, anti-inflammatory properties, and establishment of healthy gut microbiota.

Characterization of long-chain fatty acid-linked bile acids: a major conjugation form of 3β-hydroxy bile acids in feces

Although most bile acids (BAs) in feces are present in noncovalent forms that can be extracted with ethanol, non-negligible amounts of saponifiable BAs are also present. It is a major concern that such saponifiable BAs are routinely omitted from fecal BA measurements. We compared the BA profiles of healthy stools that were obtained with/without alkaline hydrolysis and found that as much as 29.7% (2.1–67.7%) of total BAs were saponifiable. Specifically, alkaline treatment led to significant elevations of isodeoxycholic acid (isoDCA) and isolithocholic acid (isoLCA) concentrations, suggesting that considerable proportions of isoDCA and isoLCA were esterified. Precursor ion scan data from LC/MS suggested the presence of long-chain FA-linked BAs. We chemically synthesized a series of fatty acid 3β-acyl conjugates of isoDCA and isoLCA as analytical standards and analyzed their fecal profiles from newborns to adults (n = 64) by LC/MS. FA-conjugated isobile acids (FA-isoBAs) were constantly present from 2 years of age to adulthood. C16- and C18-chain FA-isoBA esters were predominantly found regardless of age, but small amounts of acetic acid esters were also found. FA-isoBA concentrations were not correlated to fecal FA concentrations. Interestingly, there were some adults who did not have FA-isoBAs. Gut bacteria involved in the production of FA-isoBAs have not been identified yet. The present study provides insight into the establishment of early gut microbiota and the interactive development of esterified BAs.The contribution of FA-isoBAs to gut physiology and their role in pathophysiologic conditions such as inflammatory bowel disease are currently under investigation.

Exploring the Potential of Human Milk and Formula Milk on Infants’ Gut and Health

Early-life gut microbiota plays a role in determining the health and risk of developing diseases in later life. Various perinatal factors have been shown to contribute to the development and establishment of infant gut microbiota. One of the important factors influencing the infant gut microbial colonization and composition is the mode of infant feeding. While infant formula milk has been designed to resemble human milk as much as possible, the gut microbiome of infants who receive formula milk differs from that of infants who are fed human milk. A diverse microbial population in human milk and the microbes seed the infant gut microbiome. Human milk contains nutritional components that promote infant growth and bioactive components, such as human milk oligosaccharides, lactoferrin, and immunoglobulins, which contribute to immunological development. In an attempt to encourage the formation of a healthy gut microbiome comparable to that of a breastfed infant, manufacturers often supplement infant formula with prebiotics or probiotics, which are known to have a bifidogenic effect and can modulate the immune system. This review aims to elucidate the roles of human milk and formula milk on infants’ gut and health.

Opposing Growth Responses of Lepidopteran Larvae to the Establishment of Gut Microbiota.

Gut microbiota can have diverse impacts on hosts, the nature of which often depend on the circumstances. For insect gut microbes, the quality and nature of host diets can be a significant force in swinging the pendulum from inconsequential to functionally important. In our study, we addressed whether beneficial microbes in one species impart similar functions to related species under identical conditions. Using fall armyworm (Spodoptera frugiperda), beet armyworm (Spodoptera exigua), and other noctuid hosts, we implemented an axenic rearing strategy and manipulated gut bacterial populations and dietary conditions. Our results revealed that some gut Enterococcus and Enterobacter isolates can facilitate utilization of a poor diet substrate by fall armyworm, but this was not the case for other more optimized diets. While Enterococcus provided benefits to fall armyworm, it was decidedly antagonistic to beet armyworm (Spodoptera exigua) under identical conditions. Unique isolates and bacterial introductions at early growth stages were critical to how both larval hosts performed. Our results provide robust evidence of the roles in which bacteria support lepidopteran larval growth, but also indicate that the directionality of these relationships can differ among congener hosts. IMPORTANCE Insects have intimate relationships with gut microbiota, where bacteria can contribute important functions to their invertebrate hosts. Lepidopterans are important insect pests, but how they engage with their gut bacteria and how that translates to impacts on the host are lacking. Here we demonstrate the facultative nature of gut microbiota in lepidopteran larvae and the importance of diet in driving mutualistic or antagonistic relationships. Using multiple lepidopteran species, we uncover that the same bacteria that can facilitate exploitation of a challenging diet in one host severely diminishes larval performance of another larval species. Additionally, we demonstrate the beneficial functions of gut microbiota on the hosts are not limited to one lineage, but rather multiple isolates can facilitate the exploitation of a suboptimal diet. Our results illuminate the context-dependent nature of the gut microbiomes in invertebrates, and how host-specific microbial engagement can produce dramatically different interactions.