Microbiome of the first stool after birth and infantile colic

Why do babies cry? Exploring the role of the gut microbiota in infantile colic, constipation, and cramps in the KOALA birth cohort study

Gastrointestinal symptoms are common during infancy, including infantile colic. Colic can be loosely defined as prolonged and recurrent crying without obvious cause. The cause indeed remains unclear despite much research. Results on infant nutrition are inconclusive, but prior work has linked maternal mental health to infant crying. Recently, several small studies have described associations between gut microbiota and colic. We used a larger cohort to examine the role of the microbiota in infant gastrointestinal health, while also accounting for other biopsychosocial factors. Using fecal 16S rRNA gene amplicon sequencing data from 1,012 infants in the KOALA birth cohort, we examined associations between the 1-month gut microbiota and parent-reported functional gastrointestinal symptoms throughout infancy, including colic, constipation, and cramps. These analyses were adjusted for biopsychosocial factors that were associated with symptoms in a broader analysis involving 2,665 participants. In 257 infants, we also explored associations between breastmilk human milk oligosaccharides (HMOs) and gastrointestinal symptoms. Higher relative abundance of Staphylococcus at one month was associated with less constipation in the first three months of life. Conversely, Ruminococcus gnavus group abundance was associated with more colicky symptoms, particularly between four and seven months. Breastmilk concentrations of the HMOs lacto-N-hexaose (LNH) and lacto-N-neohexaose (LNnH) were associated with less constipation in the first three months. Our results support the conclusion that gut microbiota are relevant in infantile colic and constipation. However more work is needed to elucidate the underlying mechanisms, and explore their interplay with other relevant biopsychosocial factors such as maternal mental health.

Is there a role for nutritional advice during breastfeeding for infant colic relief? A mixed-method study

Objective

This study aimed to explore the extent and impact of maternal dietary change for colic relief in a cohort of breastfeeding women.

Method

A mixed-method non-sequential approach was devised, including a web-based survey (n = 66) and three semi-structured interviews.

Results

Most women (70 %) changed their diet while breastfeeding a baby with colic and perceived a positive impact on their babies (63 %). The choice of foods eliminated was individual, based on a process of trial and error and on the perceived benefit to the baby. A sub-group of colicky babies, those with less intense colic symptoms, benefited significantly from the removal of cruciferous vegetables (p = 0.01) and were found to be 'less windy' (p = 0.10, ES0,20), a result trending towards statistical significance. Women felt unsupported while making changes to their diet. When dietary change brought relief to the baby, it turned into a coping tool for women facilitating extended breastfeeding.

Conclusions

Maternal dietary change can play a positive role in providing relief to breastfed babies with colic. Novel findings from this study revealed that different baby subtypes got relief from the elimination of different foods. This underscores the potential of personalised nutritional advice for colic relief in breastfed babies.

The gut core microbial species Bifidobacterium longum: Colonization, mechanisms, and health benefits

Bifidobacterium longum (B. longum) is a species of the core microbiome in the human gut, whose abundance is closely associated with host age and health status. B. longum has been shown to modulate host gut microecology and have the potential to alleviate various diseases. Comprehensive understanding on the colonization mechanism of B. longum and mechanism of the host-B. longum interactions, can provide us possibility to prevent and treat human diseases through B. longum-directed strategies. In this review, we summarized the gut colonization characteristics of B. longum, discussed the diet factors that have ability/potential to enrich indigenous and/or ingested B. longum strains, and reviewed the intervention mechanisms of B. longum in multiple diseases. The key findings are as follows: First, B. longum has specialized colonization mechanisms, like a wide carbohydrate utilization spectrum that allows it to adapt to the host's diet, species-level conserved genes encoding bile salt hydrolase (BSHs), and appropriate bacterial surface structures. Second, dietary intervention (e.g., anthocyanins) could effectively improve the gut colonization of B. longum, demonstrating the feasibility of diet-tuned strain colonization. Finally, we analyzed the skewed abundance of B. longum in different types of diseases and summarized the main mechanisms by which B. longum alleviates digestive (repairing the intestinal mucosal barrier by stimulating Paneth cell activity), immune (up-regulating the regulatory T cell (Treg) populations and maintaining the balance of Th1/Th2), and neurological diseases (regulating the kynurenine pathway and quinolinic acid levels in the brain through the gut-brain axis).

Temporal Investigation of the Maternal Origins of Fetal Gut Microbiota

In utero colonization or deposition of beneficial microorganisms and their by-products likely occurs through various mechanisms, such as hematogenous spread or ascension from the reproductive tract. With high-throughput sequencing techniques, the identification of microbial components in first-pass neonatal meconium has been achieved. While these components are low-biomass and often not abundant enough to culture, the presence of microbial DNA signatures may promote fetal immune tolerance or epigenetic regulation prior to birth. The aim of this study was to investigate the maternal source of the neonatal first-pass meconium microbiome. Maternal vaginal and anal samples collected from twenty-one maternal-infant dyad pairs were compared via principal component analysis to first-pass neonatal meconium microbial compositions. Results demonstrated the greatest degree of similarity between the maternal gut microbiome in the second and third trimesters and vaginal microbiome samples across pregnancy, suggesting that the maternal gut microbiota may translocate to the fetal gut during pregnancy. This study sheds light on the origin and timing of the potential transfer of maternal microbial species to offspring in utero.

Antibiotics Use and Its Effects on the Establishment of Feeding Tolerance in Preterm Neonates

OBJECTIVE

Antibiotics are one of the most widely used medications in today's neonatal intensive care units. Indiscriminate antibiotic usage persists in preterm newborns who are symptomatic due to factors linked to prematurity rather than being septic. Previous studies in older infants suggest that prior antibiotic administration is associated with possible dysmotility and microbial dysbiosis in the intestinal tract. We hypothesize that early antibiotic administration impacts high-risk preterm infants' tolerance to enteral feeding advancement.

STUDY DESIGN

As part of the Routine Early Antibiotic Use in SymptOmatic Preterm Neonates study, symptomatic preterm newborns without maternal infection risk factors were randomized to receive or not receive antibiotics, with C1 receiving antibiotics and C2 not. Of the 55 newborns that underwent pragmatic randomization, 28 preterm neonates in group C1 received antibiotics.

RESULTS

The premature neonates in the randomized groups who received antibiotics and those who did not showed no differences in sustained feeding tolerance.

CONCLUSION

Our investigation of the risk of feeding issues in babies who get antibiotics early in life revealed no differences between neonates who received antibiotics and those who did not when the randomized controlled trial data alone was reviewed. Given the sample sizes, it is uncertain if the preceding analysis is powerful enough to detect differences (a significant percentage of neonates who were randomly assigned to NOT get antibiotics subsequently received early treatment due to changing clinical conditions). This affirms the requirement for a meticulously designed prospective randomized study.

KEY POINTS

· Defining feeding tolerance for the first time in neonates.. · Patients from the REASON trial were evaluated.. · Preterm neonates were the focus of this study..

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.

Investigating prenatal and perinatal factors on meconium microbiota: a systematic review and cohort study

BACKGROUND

The first-pass meconium has been suggested as a proxy for the fetal gut microbiota because it is formed in utero. This systematic review and cohort study investigated how pre- and perinatal factors influence the composition of the meconium microbiota.

METHODS

We performed the systematic review using Covidence by searching PubMed, Scopus, and Web of Science databases with the search terms "meconium microbiome" and "meconium microbiota". In the cohort study, we performed 16 S rRNA gene sequencing on 393 meconium samples and analyzed the sequencing data using QIIME2.

RESULTS

Our systematic review identified 69 studies exploring prenatal factors, immediate perinatal factors, and microbial composition in relation to subsequent health of infants but gave only limited comparative evidence regarding factors related to the composition of the meconium microbiota. The cohort study pointed to a low-biomass microbiota consisting of the phyla Firmicutes, Proteobacteria and Actinobacteriota and the genera Staphylococcus, Escherichia-Shigella and Lactobacillus, and indicated that immediate perinatal factors affected the composition of the meconium microbiota more than did prenatal factors.

CONCLUSIONS

This finding supports the idea that the meconium microbiota mostly starts developing during delivery.

IMPACT

It is unclear when the first-pass meconium microbiota develops, and what are the sources of the colonization. In this systematic review, we found 69 studies exploring prenatal factors, immediate perinatal factors, and microbial composition relative to subsequent health of infants, but there was no consensus on the factors affecting the meconium microbiota development. In this cohort study, immediate perinatal factors markedly affected the meconium microbiota development while prenatal factors had little effect on it. As the meconium microbiota composition was influenced by immediate perinatal factors, the present study supports the idea that the initial gut microbiota develops mainly during delivery.

Preventing and Treating Colic: An Update

Infantile colic (IC) is c is a self-limiting functional gastrointestinal disorder (FGID) with a favorable natural history. Worldwide, IC has a significant impact on many newborns and their families. Although not an indication of an illness, its symptoms are wide and generic and may indicate a potentially serious underlying issue in a tiny percentage of newborns who may require a medical evaluation. The pathogenesis appears to be multifactorial implying a complex relationship between the infant and the environment. One of the most studied theories attributes a key role to the gut microbiota in the pathogenesis of IC. A variety of approaches have been suggested for the clinical management of IC, and several randomized controlled trials have been reported in the literature. Probiotics can change the host's microbiota and positively impact health. They may be able to restore balance and create a better intestinal microbiota landscape since there is mounting evidence that the gut microbial environment of colicky newborns differs from that of healthy infants. In this review, we revise the most commonly studied probiotics and mixtures to treat and prevent IC and the most recent recommendations.

Lactobacillus reuteri in digestive system diseases: focus on clinical trials and mechanisms

Objectives

Digestive system diseases have evolved into a growing global burden without sufficient therapeutic measures. Lactobacillus reuteri (L. reuteri) is considered as a new potential economical therapy for its probiotic effects in the gastrointestinal system. We have provided an overview of the researches supporting various L. reuteri strains' application in treating common digestive system diseases, including infantile colic, diarrhea, constipation, functional abdominal pain, Helicobacter pylori infection, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases.

Methods

The summarized literature in this review was derived from databases including PubMed, Web of Science, and Google Scholar.

Results

The therapeutic effects of L. reuteri in digestive system diseases may depend on various direct and indirect mechanisms, including metabolite production as well as modulation of the intestinal microbiome, preservation of the gut barrier function, and regulation of the host immune system. These actions are largely strain-specific and depend on the activation or inhibition of various certain signal pathways. It is well evidenced that L. reuteri can be effective both as a prophylactic measure and as a preferred therapy for infantile colic, and it can also be recommended as an adjuvant strategy to diarrhea, constipation, Helicobacter pylori infection in therapeutic settings. While preclinical studies have shown the probiotic potential of L. reuteri in the management of functional abdominal pain, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases, its application in these disease settings still needs further study.

Conclusion

This review focuses on the probiotic effects of L. reuteri on gut homeostasis via certain signaling pathways, and emphasizes the importance of these probiotics as a prospective treatment against several digestive system diseases.

Compositional and functional variability of the gut microbiome in children with infantile colic

The inconsolable crying of a child for no apparent reason at an early age is a source of excitement and anxiety for parents. Previous studies have reported that crying may be caused by discomfort associated with the occupation of the intestines of the newborn by microbiota and its vital activity. We conducted a prospective observational study in which 62 newborns and their mothers were recruited. The study comprised two groups, each consisting of 15 infants with colic and 21 controls. Colic and control groups were vaginally born and exclusively breastfed. Fecal samples from children were collected over time from day 1 to 12 months. Full metagenomic sequencing of fecal samples from children and their mothers was carried out. It was determined that the trajectory of the development of the intestinal microbiome of children with colic was different from the group without colic. In the colic group, a depleted relative abundance of Bifidobacterium and enrichment of Bacteroides Clostridiales was found, while the microbial biodiversity in this group was enriched. Metabolic pathway profiling showed that the non-colic group was enriched by amino acid biosynthetic pathways, while the feces microbiome of the colic group was enriched by glycolysis metabolic pathways that correlated with the Bacteroides taxon. This study shows that infantile colic has a definite relationship with the microbiome structure of infants.

Infantile Colic and the Subsequent Development of the Irritable Bowel Syndrome

Background/Aims

Little is known about the association between infantile colic and the later onset of irritable bowel syndrome (IBS).

Methods

This study examined all 917 707 children who were born in Korea between 2007 and 2008. Infantile colic was defined with 1 or more diagnoses of ICD-10 code R10.4 or R68.1 at the age of 5 weeks to 4 months, and infants with a diagnosis of infantile colic and without were allocated into the infantile colic group and the control group. IBS was defined as 2 or more diagnoses of ICD-10 code K58.X after 4 years of age. Each child was traced until 2017. The risk of IBS with infantile colic was evaluated using a Cox proportional hazards model with propensity score inverse probability of treatment weighting (IPTW).

Results

After IPTW, 363 528 and 359 842 children were allocated to the control group and the infantile colic group, respectively. The infantile colic group had a higher risk of developing IBS in childhood (hazard ratio [95% CI], 1.12 [1.10 to 1.13]) than the control group. Moreover, the subgroup analyses according to the feeding status, birth weight, sex, or economic status, showed that the risk of IBS with former infantile colic remained statistically significant.

Conclusions

Children with a diagnosis of infantile colic during the infant period had a significant risk of developing IBS after 4 years of age. Understanding the pathogenesis of infantile colic in the neonatal period may reduce the prevalence and severity of functional gastrointestinal disorders from childhood to adolescence to adulthood.

Infant behavioral state and stool microbiome in infants receiving Lactocaseibacillus rhamnosus GG in formula: randomized controlled trial

Background

Our aim was to evaluate infant behavioral state, stool microbiome profile and calprotectin in infants with infantile colic receiving a partially hydrolyzed protein formula with or without added Lacticaseibacillus (formerly Lactobacillus) rhamnosus GG (LGG).

Methods

In this single-center, double-blind, controlled, parallel, prospective study, term infants (14–28 days of age) identified with colic (using modified Wessel’s criteria: cried and/or fussed ≥ 3 h/day for ≥ 3 days/week, in a one-week period) were randomized to receive one of two formulas over a three-week feeding period: marketed partially hydrolyzed cow’s milk-based infant formula (PHF, n = 35) or a similar formula with added LGG (PHF-LGG, n = 36). Parent-reported infant behavior was recorded at three time points (Study Days 2–4, 10–12, and 18–20). Duration (hours/day) of crying/fussing (averaged over each three-day period) was the primary outcome. Stool samples were collected at Baseline and Study End (Days 19–21) to determine stool LGG colonization (by qPCR) and microbial abundance (using 16S rRNA gene sequencing) and calprotectin (μg/g).

Results

Duration of crying/fussing (mean ± SE) decreased and awake/content behavior increased over time with no significant group differences over the course of the study. There were no group differences in the percentage of infants who experienced colic by study end. Colic decreased by Study End vs Baseline in both groups. Change in fecal calprotectin also was similar between groups. Comparing Study End vs Baseline, LGG abundance was greater in the PHF-LGG group (P < 0.001) whereas alpha diversity was greater in the PHF group (P = 0.022). Beta diversity was significantly different between PHF and PHF-LGG at Study End (P = 0.05). By study end, relative abundance of L. rhamnosus was higher in the PHF-LGG vs PHF group and vs Baseline.

Conclusions

In this pilot study of infants with colic, both study formulas were well tolerated. Crying/fussing decreased and awake/content behavior increased in both study groups over the course of the study. Study results demonstrate a successful introduction of the probiotic to the microbiome. The partially hydrolyzed protein formula with added LGG was associated with significant changes in the gut microbiome.

Trial registration

ClinicalTrials.gov, ClinicalTrials.gov Identifier: NCT02340143. Registered 16/01/2015.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03647-x.

The Gastrointestinal Microbiome in Infant Colic: A Scoping Review

ABSTRACT

The significant crying of infantile colic adds stress to the infant and their family, yet it has no recognized etiology. Gastrointestinal health problems and dysfunction have been suspected in the etiology of colic. Disruptions to the microbiome colonization of the gastrointestinal system may lead to excess gas and inflammation that are associated with the crying of colic. Infants with colic have increased colonization with gas-producing bacteria, like Escherichia coli and Klebsiella , and they have lower colonization of anti-inflammatory bacteria, like Bifidobacterium and Lactobacillus . Colic is known to self-resolve around 3 months of age. However, few researchers have investigated how the microbiome may be changing at colic's natural resolution without the intervention of a probiotic. With a better understanding of what leads to colic's self-resolution, future researchers may be able to identify more effective therapies for colic prevention or treatment. This scoping review presents the collective evidence from 21 original, primary research articles on what is known about the gastrointestinal microbiome at colic onset and resolution.

New Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus strains: well tolerated and improve infant microbiota

BACKGROUND

Different microorganisms from the environment will begin to colonise the infant during and immediately after the delivery. It could be advantageous to influence the microbiome early on by giving infants probiotic bacteria. The aim of the study was to investigate the tolerance of two probiotic lactobacilli in infants. The effect on the microbiota was also followed.

METHODS

Thirty-six healthy infants, aged 4-83 days at the start of the study, were given a daily supplementation of probiotics (Lactiplantibacillus plantarum HEAL9 and Lacticaseibacillus rhamnosus 271, 10⁹ CFU (colony-forming units)) or placebo for 8 weeks. Adverse events, growth parameters, the faecal microbiome and intestinal performance were followed.

RESULTS

No differences between the groups in growth parameters, adverse events and intestinal performance were observed. The faecal levels of L. plantarum, L. rhamnosus and lactobacilli increased after the intake of probiotics and were significantly higher compared with the placebo group after 4 and 8 weeks of intake. The faecal microbial diversity was similar in the two groups at the end of the study.

CONCLUSIONS

The intervention with the probiotic formulation was well tolerated and increased the level of lactobacilli in the intestine. The developed probiotic formulation will be further evaluated for clinical efficacy in infants.

IMPACT

New data for the development of the gut function and the microbiome in breastfed and/or formula-fed young infants over time and the effect of adding two probiotic strains are presented. Lactiplantibacillus plantarum is a species that seldom has been analysed in infants, but it could be detected in 25% of the subjects before administration (mean age 41 days). Lactiplantibacillus plantarum and L. rhamnosus establish well in the intestine of infants and are well tolerated. The microbiota was positively affected by the intake of probiotics.

Microbiota of the first-pass meconium and subsequent atopic and allergic disorders in children

BACKGROUND

Some cohort studies have suggested that gut microbiota composition is associated with allergic diseases in children. The microbiota of the first-pass meconium, which forms before birth, represents the first gut microbiota that is easily available for research and little is known about any relationship with allergic disease development.

OBJECTIVE

We investigated whether the bacterial composition of the first-pass meconium is associated with the development of allergic diseases before 4 years of age.

METHODS

Prospective birth cohort study. Bacterial composition of first-pass meconium was analysed using bacterial 16S rRNA gene amplicon sequencing. Atopic and allergic diseases were evaluated via online survey or telephone to age 4 years, based on the International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

During a 6-week period in 2014, 312 children were born at the Central Finland Central Hospital. Meconium was collected from 212 at a mean of 8-hour age. Outcome data at 4 years were available for 177 (83%) children, and 159 of these had sufficient amplification of bacterial DNA in meconium. Meconium microbiota composition, including diversity indices and relative abundances of the main phyla and genera, was not associated with subsequent atopic eczema, wheezing or cow's milk allergy. Principal components analysis did not identify any clustering of the meconium microbiomes of children with respect to wheezing or cow's milk allergy.

CONCLUSIONS

We found no evidence that gut microbiota composition of first-pass meconium is associated with atopic manifestations to age 4 years. However, larger studies are needed to fully exclude a relationship.

Faecal Microbiota in Infants and Young Children with Functional Gastrointestinal Disorders: A Systematic Review

Functional gastrointestinal disorders (FGIDs) refer to gastrointestinal tract issues that lack clear structural or biochemical causes. Their pathophysiology is still unclear, but gut microbiota alterations are thought to play an important role. This systematic review aimed to provide a comprehensive overview of the faecal microbiota of infants and young children with FGIDs compared to healthy controls. A systematic search and screening of the literature resulted in the inclusion of thirteen full texts. Most papers reported on infantile colic, only one studied functional constipation. Despite methodological limitations, data show alterations in microbial diversity, stability, and colonisation patterns in colicky infants compared to healthy controls. Several studies (eight) reported increases in species of (pathogenic) Proteobacteria, and some studies (six) reported a decrease in (beneficial) bacteria such as Lactobacilli and Bifidobacteria. In addition, accumulation of related metabolites, as well as low-grade inflammation, might play a role in the pathophysiology of infantile colic. Infants and toddlers with functional constipation had significantly lower levels of Lactobacilli in their stools compared to controls. Microbial dysbiosis and related changes in metabolites may be inherent to FGIDs. There is a need for more standardised methods within research of faecal microbiota in FGIDs to obtain a more comprehensive picture and understanding of infant and childhood FGIDs.

Meconium Microbiome of Very Preterm Infants across Germany

Meconium constitutes infants' first bowel movements postnatally. The consistency and microbial load of meconium are different from infant and adult stool. While recent evidence suggests that meconium is sterile in utero, rapid colonization occurs after birth. The meconium microbiome has been associated with negative health outcomes, but its composition is not well described, especially in preterm infants. Here, we characterized the meconium microbiomes from 330 very preterm infants (gestational ages 28 to 32 weeks) from 15 hospitals in Germany and in fecal samples from a subset of their mothers (N = 217). Microbiome profiles were compiled using 16S rRNA gene sequencing with negative and positive controls. The meconium microbiome was dominated by Bifidobacterium, Staphylococcus, and Enterococcus spp. and was associated with gestational age at birth and age at sample collection. Bifidobacterial abundance was negatively correlated with potentially pathogenic genera. The amount of bacterial DNA in meconium samples varied greatly across samples and was associated with the time since birth but not with gestational age or hospital site. In samples with low bacterial load, human mitochondrial sequences were highly amplified using commonly used, bacterial-targeted 16S rRNA primers. Only half of the meconium samples contained sufficient bacterial material to study the microbiome using a standard approach. To facilitate future meconium studies, we present a five-level scoring system (“MecBac”) that predicts the success of 16S rRNA bacterial sequencing for meconium samples. These findings provide a foundational characterization of an understudied portion of the human microbiome and will aid the design of future meconium microbiome studies.

IMPORTANCE Meconium is present in the intestines of infants before and after birth and constitutes their first bowel movements postnatally. The consistency, composition and microbial load of meconium is largely different from infant and adult stool. While recent evidence suggests that meconium is sterile in utero, rapid colonization occurs after birth. The meconium microbiome has been associated with short-term and long-term negative health outcomes, but its composition is not yet well described, especially in preterm infants. We provide a characterization of the microbiome structure and composition of infant meconium and maternal feces from a large study cohort and propose a method to evaluate meconium samples for bacterial sequencing suitability. These findings provide a foundational characterization of an understudied portion of the human microbiome and will aid the design of future meconium microbiome studies.

Presence of distinctive microbiome in the first-pass meconium of newborn infants

We critically evaluated the fetal microbiome concept in 44 neonates with placenta, amniotic fluid, and first-pass meconium samples. Placental histology showed no signs of inflammation. Meconium samples were more often bacterial culture positive after vaginal delivery. In next-generation sequencing of the bacterial 16S gene, before and after removal of extracellular and PCR contaminant DNA, the median number of reads was low in placenta (48) and amniotic fluid (46) and high in meconium samples (14,556 C-section, 24,860 vaginal). In electron microscopy, meconium samples showed extracellular vesicles. Utilizing the analysis of composition of microbiomes (ANCOM) against water, meconium samples had a higher relative abundance of Firmicutes, Lactobacillus, Streptococcus, and Escherichia-Shigella. Our results did not support the existence of the placenta and amniotic fluid microbiota in healthy pregnancies. The first-pass meconium samples, formed in utero, appeared to harbor a microbiome that may be explained by perinatal colonization or intrauterine colonization via bacterial extracellular vesicles.

Human milk oligosaccharides alleviate stress-induced visceral hypersensitivity and associated microbiota dysbiosis

Pain-related functional gastrointestinal disorders (FGIDs) are characterized by visceral hypersensitivity (VHS) associated with alterations in the microbiota-gut-brain axis. Since human milk oligosaccharides (HMOs) modulate microbiota, gut and brain, we investigated whether HMOs impact VHS, and explored the role of gut microbiota. To induce VHS, C57BL/6JRj mice received hourly water avoidance stress (WAS) sessions for 10 d, or antibiotics (ATB) for 12 d. Challenged and unchallenged (Sham) animals were fed AIN93M diet (Cont) or AIN93M containing 1% of a 6-HMO mix (HMO6). VHS was assessed by monitoring the visceromotor response to colorectal distension. Fecal microbiome was analyzed by shotgun metagenomics. The effect of HMO6 sub-blends on VHS and nociceptive pathways was further tested using the WAS model. In mice fed Cont, WAS and ATB increased the visceromotor response to distension. HMO6 decreased WAS-mediated electromyographic rise at most distension volumes and overall Area Under Curve (AUC=6.12±0.50 in WAS/HMO6 vs. 9.46±0.50 in WAS/Cont; P<.0001). In contrast, VHS in ATB animals was not improved by HMO6. In WAS, HMO6 promoted most microbiota taxa and several functional pathways associated with low VHS and decreased those associated with high VHS. Among the sub-blends, 2'FL+DFL and LNT+6'SL reduced visceromotor response close to Sham/Cont values and modulated serotoninergic and CGRPα-related pathways. This research further substantiates the capacity of HMOs to modulate the microbiota-gut-brain communication and identifies mitigation of abdominal pain as a new HMO benefit. Ultimately, our findings suggest the value of specific HMO blends to alleviate pain associated FGIDs such as infantile colic or Irritable Bowel Syndrome.

Delivery mode and perinatal antibiotics influence the predicted metabolic pathways of the gut microbiome

Delivery mode and perinatal antibiotics influence gut microbiome composition in children. Most microbiome studies have used the sequencing of the bacterial 16S marker gene but have not reported the metabolic function of the gut microbiome, which may mediate biological effects on the host. Here, we used the PICRUSt2 bioinformatics tool to predict the functional profiles of the gut microbiome based on 16S sequencing in two child cohorts. Both Caesarean section and perinatal antibiotics markedly influenced the functional profiles of the gut microbiome at the age of 1 year. In machine learning analysis, bacterial fatty acid, phospholipid, and biotin biosynthesis were the most important pathways that differed according to delivery mode. Proteinogenic amino acid biosynthesis, carbohydrate degradation, pyrimidine deoxyribonucleotide and biotin biosynthesis were the most important pathways differing according to antibiotic exposure. Our study shows that both Caesarean section and perinatal antibiotics markedly influence the predicted metabolic profiles of the gut microbiome at the age of 1 year.

Remodeling of the maternal gut microbiome during pregnancy is shaped by parity

BACKGROUND

The maternal microbiome has emerged as an important factor in gestational health and outcome and is associated with risk of preterm birth and offspring morbidity. Epidemiological evidence also points to successive pregnancies-referred to as maternal parity-as a risk factor for preterm birth, infant mortality, and impaired neonatal growth. Despite the fact that both the maternal microbiome and parity are linked to maternal-infant health, the impact of parity on the microbiome remains largely unexplored, in part due to the challenges of studying parity in humans.

RESULTS

Using synchronized pregnancies and dense longitudinal monitoring of the microbiome in pigs, we describe a microbiome trajectory during pregnancy and determine the extent to which parity modulates this trajectory. We show that the microbiome changes reproducibly during gestation and that this remodeling occurs more rapidly as parity increases. At the time of parturition, parity was linked to the relative abundance of several bacterial species, including Treponema bryantii, Lactobacillus amylovorus, and Lactobacillus reuteri. Strain tracking carried out in 18 maternal-offspring "quadrads"-each consisting of one mother sow and three piglets-linked maternal parity to altered levels of Akkermansia muciniphila, Prevotella stercorea, and Campylobacter coli in the infant gut 10 days after birth.

CONCLUSIONS

Collectively, these results identify parity as an important environmental factor that modulates the gut microbiome during pregnancy and highlight the utility of a swine model for investigating the microbiome in maternal-infant health. In addition, our data show that the impact of parity extends beyond the mother and is associated with alterations in the community of bacteria that colonize the offspring gut early in life. The bacterial species we identified as parity-associated in the mother and offspring have been shown to influence host metabolism in other systems, raising the possibility that such changes may influence host nutrient acquisition or utilization. These findings, taken together with our observation that even subtle differences in parity are associated with microbiome changes, underscore the importance of considering parity in the design and analysis of human microbiome studies during pregnancy and in infants. Video abstract.

Efficacy of Bifidobacterium breve CECT7263 for infantile colic treatment: an open-label, parallel, randomised, controlled trial

Infantile colic is a prevalent condition characterised by excessive crying with no effective treatment available. We aimed to evaluate the efficacy of Bifidobacterium breve CECT7263 and a combination of this and Lactobacillus fermentum CECT5716 versus simethicone in reducing the daily time spent crying in colicky infants. A multicentre randomised, open-label, parallel, controlled trial of 28 days was performed in 150 infants who were diagnosed with colic according to the Rome III criteria and who randomly received simethicone (80 mg/day; Simethicone group), B. breve CECT7263 (2×10⁸ cfu/day, Bb group), or a combination of L. fermentum CECT5716 and B. breve CECT7263 (1×10⁸ cfu/day per strain, Bb+Lf group). The main outcomes were minutes of crying per day and the percentage of reduction in daily crying from baseline. Data were analysed per intention to treat. All treatments significantly decreased the daily crying time at the end of the intervention (P-time <0.001). However, the infants in the Bb group had significantly decreased crying time from the first week of the study (P<0.05), whereas the Bb+Lf group and the simethicone group had significantly decreased crying time from the second week (P<0.05). The percentage of reduction in the minutes of crying from baseline in the Bb group was significantly higher than that in the Simethicone group every week of the intervention (-40.3 vs -27.6% at 1-week; -59.2 vs -43.2% at 2-weeks; -64.5 vs -53.5% at 3-week and -68.5 vs -59.5% at 4-weeks, P<0.05). Additionally, in the Bb group, infants had better night sleep, and parents reported a more positive mood at the end of the intervention. All the products used in the study were safe and well tolerated. In conclusion, the breastmilk-isolated probiotic strain B. breve CECT7263 is a safe and effective treatment for infantile colic, presenting an earlier and more robust effect than the reference prescribed drug, simethicone.

The influence of the gastrointestinal microbiome on infant colic

INTRODUCTION

Although infantile colic is relatively frequent, its pathophysiology is not yet understood. The aim of this paper is to provide a better understanding of the link between infantile colic and the gastrointestinal microbiome.

AREAS COVERED

The gastro-intestinal microbiome may already start to develop in the womb and grows exponentially immediately after birth. Factors influencing the microbiome can cause dysbiosis and precipitate symptoms of colic through several mechanisms such as increased gas production and low grade gut inflammation. Other possible factors are immaturity of the enterohepatic bile acid cycle and administration of antibiotics and other medications during the perinatal period. An effective treatment for all colicky infants has yet to be discovered, but the probiotic Lactobacillus reuteri DSM17938 was shown to be effective in breastfed infants with colic. The scientific databases 'Pubmed' and 'Google scholar' were searched from inception until 02/2020. Relevant articles were selected based on the abstract.

EXPERT OPINION

Recent literature confirmed that the composition of the gastrointestinal microbiome is associated with the development of infantile colic. It can be speculated that full sequencing and bioinformatics analysis to identify the microbiome down to the species level may provide answers to the etiology and management of infantile colic.