Mapping the early life gut microbiome in neonates with critical congenital heart disease: multiomics insights and implications for host metabolic and immunological health

Gut microbiota promotes cholesterol gallstone formation through the gut-metabolism-gene axis

BACKGROUND

Gallstone disease, arising from the interplay between host metabolism and gut microbiota, represents a significant health concern. Dysbiosis of the gut microbiome and disruptions in circadian rhythm contribute to the pathogenesis of gallstones. This study conducted a comprehensive analysis of gut microbiota and metabolites derived from stool and serum samples of 28 patients with cholesterol gallstones (CGS) and 19 healthy controls, employing methodologies such as 16S rRNA sequencing, metaproteomics, metabolomics, and host genetic analysis. Additionally, a retrospective cohort study was utilized to assess the efficacy of probiotics or ursodeoxycholic acid (UDCA) in preventing CGS formation post-bariatric surgery.

RESULTS

In CGS patients, gut microbiota diversity shifted, with harmful bacteria rising and beneficial ones declining. The altered microbiota primarily affected amino acid, lipid, nucleotide, and carbohydrate metabolism. Metabolic abnormalities were noted in amino acids, glucose, lipids, and bile acids with decreased levels of ursodeoxycholic, glycosodeoxycholic, and glycolithocholic acids, and increased glycohyodeoxycholic and allocholic acids. Glutamine and alanine levels dropped, while phenylalanine and tyrosine rosed. Animal studies confirmed gene changes in gallbladder tissues related to bile acid, energy, glucose, and lipid metabolism. Importantly, UDCA and probiotics effectively reduced CGS risk post-bariatric surgery, especially when combined.

CONCLUSIONS

Multi-omics can clarify CGS pathology, by focusing on the gut-metabolism-gene axis, paving the way for future studies on CGS prevention and treatment through gut microbiota or metabolic interventions.

Isobutyrate Confers Resistance to Inflammatory Bowel Disease through Host-Microbiota Interactions in Pigs

Supplementation with short-chain fatty acids (SCFAs) is a potential therapeutic approach for inflammatory bowel disease (IBD). However, the therapeutic effects and mechanisms of action of isobutyrate in IBD remain unclear. Clinical data indicate that the fecal levels of isobutyrate are markedly lower in patients with Crohn's disease than in healthy controls. Compared with healthy mice and healthy pigs, mice and pigs with colitis presented significantly lower isobutyrate levels. Furthermore, the level of isobutyrate in pigs was significantly negatively correlated with the disease activity index. We speculate that isobutyrate may play a crucial role in regulating host gut homeostasis. We established a model of dextran sulfate sodium-induced colitis in pigs, which have gastrointestinal structure and function similar to those of humans; we performed multiomic analysis to investigate the therapeutic effects and potential mechanisms of isobutyrate on IBD at both the animal and cellular levels and validated the results. Phenotypically, isobutyrate can significantly alleviate diarrhea, bloody stools, weight loss, and colon shortening caused by colitis in pigs. Mechanistically, isobutyrate can increase the relative abundance of Lactobacillus reuteri, thereby increasing the production of indole-3-lactic acid, regulating aryl hydrocarbon receptor expression and downstream signaling pathways, and regulating Foxp3+ CD4+ T cell recruitment to alleviate colitis. Isobutyrate can directly activate G protein-coupled receptor 109A, promote the expression of Claudin-1, and improve intestinal barrier function. In addition, isobutyrate can increase the production of intestinal SCFAs and 3-hydroxybutyric acid and inhibit the TLR4/MyD88/NF-κB signaling pathway to suppress intestinal inflammation. In conclusion, our findings demonstrate that isobutyrate confers resistance to IBD through host-microbiota interactions, providing a theoretical basis for the use of isobutyrate in alleviating colitis.

The bidirectional interplay between gut dysbiosis and surgical complications: A systematic review

BACKGROUND

The gut microbiome critically influences diverse aspects of physiology and surgical recovery. Conversely, surgery alters the microbiome, potentially predisposing to complications. We aimed to clarify the bidirectional interaction between surgery and gut dysbiosis.

METHODS

On December 22nd, 2024, a systematic search of the Cochrane Library, PubMed, VHL, and WOS was completed. Relevant studies were assessed for risk of bias using STROBE and CONSORT guidelines.

RESULTS

Thirty studies, with 2500+ participants experiencing diverse procedures and complications, were incorporated. Although specifics varied, dysbiosis correlated with surgery and its complications. Patients with complications had more harmful bacteria and fewer beneficial bacteria. In some studies, probiotics reduced complications.

CONCLUSION

Gut dysbiosis is tied to postoperative complications in a complex, bidirectional relationship. Patients with surgical complications may have fewer beneficial and more pathogenic bacteria both before and after surgery. Early identification of dysbiosis and probiotic administration could predict or even reduce postoperative complications.

Efficacy and mechanism of long-snake moxibustion for treating insomnia in breast cancer survivors: study protocol for a randomized controlled trial

Background

Insomnia (difficulty falling or staying asleep) is a common issue among breast cancer survivors, significantly impacting their quality of life. Current treatments, primarily pharmacological and psychological, have limitations: the former often causes side effects, while the latter faces accessibility barriers. Long-snake moxibustion (LSM), a traditional Chinese medicine (TCM) technique, involves applying moxibustion along the governor vessel, which is an important meridian in TCM that plays a key role in regulating brain function. LSM is characterized by its minimal side effects, ease of application, and cost-effectiveness, with preliminary studies supporting its potential for treating insomnia. This study aims to further investigate the therapeutic effectiveness of LSM in alleviating insomnia among breast cancer survivors and to explore its underlying mechanisms.

Methods

This single-center, rater-masked, randomized controlled trial will enroll 100 breast cancer survivors with chronic insomnia, who will be randomly assigned in a 1:1 ratio to either the LSM group or a waitlist control group. During the 4-week treatment period, all participants will receive standard care, with the LSM group additionally receiving LSM treatment twice a week. The primary efficacy outcome is the change in Insomnia Severity Index (ISI) score at the end of the intervention. Secondary outcomes include changes in hypnotic medication use, Pittsburgh Sleep Quality Index (PSQI) scores, Piper Fatigue Scale (PFS) scores, and Functional Assessment of Cancer Therapy-Breast (FACT-B) scores. Mechanistic evaluations will assess serum biochemical markers, gut microbiota composition, and metabolomic profiles.

Discussion

If proven effective, this trial will provide critical clinical evidence supporting LSM as a viable and accessible treatment for insomnia among breast cancer survivors. The findings could influence clinical practice by offering a non-pharmacological treatment option, improving patient outcomes, and reducing dependence on pharmacological interventions. Furthermore, exploring the underlying mechanisms may enhance our understanding of how LSM works, paving the way for future research.

Clinical trial registration

http://itmctr.ccebtcm.org.cn/, identifier ITMCTR2024000578.

Progression of gut microbiome in preterm infants during the first three months

The colonization and evolution of gut microbiota early in life play a vital role in shaping a healthy, robust immune system for infant health, whether in combating short-term illness or improving long-term health outcomes. Early-life clinical practices may interrupt or disrupt the normal colonization process of the infant gut microbiota, thereby increasing disease susceptibility. In this prospective cohort study, we analyzed the gut microbiota of 46 term and 23 preterm infants using 16S rRNA gene metagenomic sequencing. Fecal samples were collected at six timepoints during the first three months of life. Notably, gestational age was the main factor contributing to differences in the meconium microbial composition. Intriguingly, our study unveiled a more homogeneous microbial composition in preterm infants with more abundant Bifidobacterium from the postnatal age (PNA) of one month. Concurrently, the beneficial bacteria Bifidobacterium and Lactobacillus gradually increased, and the potentially pathogenic bacteria Clostridium, Enterobacter, Enterococcus, Klebsiella, and Pseudomonas gradually decreased. Furthermore, our study underscored a link between decreased microbial diversity of preterm infants and exclusive breastfeeding and antibiotic exposure. Moreover, preterm infants with patent ductus arteriosus (PDA) exhibited reduced microbial diversity but higher abundances of Streptococcus oralis and Streptococcus mitis.

Antibiotic-induced gut dysbiosis: unraveling the gut-heart axis and its impact on cardiovascular health

Cardiovascular diseases (CVDs) remain the major cause of morbidity and mortality amongst people of all ages across the world. Research suggests that the initiation and progression of CVDs are associated with antibiotic-induced gut dysbiosis. Antibiotics are primarily intended to be used to treat bacterial infections, which can alter gut microbiota (GM) composition, by lowering the abundance of beneficial bacteria, like Firmicutes, Bacteroidetes, and increasing the profusion of Enterobacteriaceae, leading to harm on gut health. Additionally, it reduces short-chain fatty acids (SCFAs) and bile acid metabolism, increases trimethylamine N-oxide (TMAO) production, intestinal permeability allowing lipopolysaccharide (LPS) and TMAO into systemic circulation. SCFAs play a key role in lipid metabolism, inflammation, and strengthening of the intestinal barrier, and participate in CVDs through FFAR2 and FFAR3 receptors, whereas dysbiosis reduces SCFAs levels and worsens these effects. TMAO enhances oxidative stress, inflammation, endothelial dysfunction, and cholesterol dysregulation, thus worsening CVDs. Furthermore, LPS develops systemic inflammation, insulin resistance, and endothelial dysfunction by activating the NF-κB pathway. Dysbiosis also affects bile acid synthesis, disrupting lipid and glucose metabolism, further participating in the progression of CVDs. This article aims to explore the role of gut dysbiosis in various CVDs, including congenital heart disease, hypertension, valvular heart disease, coronary heart disease, and heart failure. Furthermore, this article aims to bridge the knowledge gap regarding the gut-heart axis by exploring how antibiotics alter the gut microbiota homeostasis, further contributing to the development of CVDs and therapeutic interventions that reduce cardiovascular risks and restore the gut microbiota homeostasis.

Trajectory of gut microbiota before and after pediatric cardiopulmonary bypass surgery

Background

Varied congenital heart disease (CHD) may induce gut microbiota dysbiosis due to intestinal hypoperfusion or/and hypoxemia. Microbiota dysbiosis has been found in preoperative infants and cardiopulmonary bypass (CPB) exacerbated it further. However, the trajectory of gut microbiota from pre- to early post-CPB and one-year later remains unexplored. We examined this trajectory in the two most common CHDs, i.e., left-to-right shunt (ventricular septal defect, VSD) vs. right-to-left shunt (tetralogy of Fallot, TOF).

Methods

We enrolled 13 infants with VSD and 11 with TOF, and collected fecal samples at pre- and early post-CPB. 10 and 12 age- and gender-matched healthy control infants were enrolled respectively. We also enrolled 13 and 9 gender- and CHD diagnosis- and operation-matched one-year post-CPB patients, and 8 age- and gender-matched healthy control children. 16S rRNA sequencing of fecal samples were performed.

Results

Compared to the control groups, both VSD and TOF pre-CPB groups had significantly increased Enterobacteriaceae and Shigella, and decreased Bifidobacterium (Ps ≤ 0.049). No significant change in microbial community diversity was observed between pre- and early post-CPB periods (Ps≥0.227). Compared with early post-CPB, one-year post-CPB groups had significantly increased short-chain fatty acids-producing microbes (Ps ≤ 0.025), and their microbial communities were close to that of the control group (Ps≥0.102). There was no significant difference in microbial communities between VSD and TOF groups in any of 3 periods (Ps≥0.055).

Conclusion

In children with VSD or TOF, gut microbiota dysbiosis existed preoperatively and were not significantly altered by CPB. One-year post-CPB, microbiota significantly improved towards normal. Similar microbial communities were found between children with VSD and TOF throughout the perioperative and long-term postoperative periods.

Amniotic fluid microbiota and metabolism with non-syndromic congenital heart defects: a multi-omics analysis

BACKGROUND AND AIMS

Recent studies have indicated possible links between the microbiota and the fetal heart, while the relevant mechanism is still unknown. This study is aims to investigate whether analyzing the microbiota and metabolic profiles of amniotic fluid collected from pregnant women whose fetuses with or without non-syndromic congenital heart defects (CHDs), during the second and third trimester of pregnancy, could offer valuable insights into CHDs.

METHODS AND RESULTS

A case-control study was conducted with 17 cases diagnosed with non-syndromic CHDs (CHDs group) and 34 controls without congenital anomalies (control group) at a ratio of 1:2. The 16 S rDNA gene sequencing and metabolomics methods were employed to assess 51 amniotic fluid samples. The amniotic fluid microbiome from the CHDs group exhibited significantly higher Shannon and Simpson indices compared to the control group. At the genus level, 240 bacterial taxa were substantially enriched in the two groups, with 93 of those taxa being highly enriched in the case group. Compared to the control group, the case group exhibited 177 metabolites that were significantly increased and 480 metabolites that were down-regulated. The differential metabolites were primarily enriched in the steroid hormone biosynthesis, bile secretion and ovarian steroidogenesis, according to KEGG analysis. The observed variations in nine metabolites could attributed to fifty-eight distinct bacterial taxa. The nine differential metabolites were mainly associated with pathways involving steroid hormone biosynthesis, bile secretion, glycolysis, tricarboxylic acid (TCA) cycle, NADPH metabolism, and acyl transfer pathways.

CONCLUSION

The CHDs group has disturbed amniotic fluid microbiota and metabolites, and more research was required to elucidate the mechanism.

Advances in understanding the effects of cardiopulmonary bypass on gut microbiota during cardiac surgery

Cardiopulmonary bypass (CPB) is an indispensable technique in cardiac surgery; however, its impact on gut microbiota and metabolites remains insufficiently studied. CPB may disrupt the intestinal mucosal barrier, altering the composition and function of gut microbiota, thereby triggering local immune responses and systemic inflammation, which may lead to postoperative complications. This narrative review examines relevant literature from PubMed, Web of Science, Google Scholar, and CNKI databases over the past decade. Keywords such as "gut microbiota," "cardiopulmonary bypass," "cardiac surgery," and "postoperative complications" were employed, with Boolean operators used to refine the search results. The review examines changes in gut microbiota before and after CPB, their role in postoperative complications, and potential strategies for modulation to improve outcomes.

Protective effect of the branched short-chain fatty acid isobutyrate on intestinal damage in weaned piglets through intestinal microbiota remodeling

BACKGROUND

Postweaning intestinal damage in piglets is a challenging issue in the livestock industry. Short-chain fatty acids (SCFAs) are important metabolic products of the gut microbiota and are widely recognized for their role in maintaining normal colonic function and regulating the intestinal immune system. However, the effects of branched short-chain fatty acid (BSCFA) isobutyrate on intestinal health remain largely unknown. This study aims to explore the potential of isobutyrate for alleviating postweaning intestinal damage.

RESULTS

This study indicates that isobutyrate can alleviate diarrhea in weaned piglets, enhance their growth performance, and optimize the gut microbiota. This is mainly achieved through increasing the relative abundance of probiotic bacteria such as Lactobacillus, Megasphaera, and Prevotellaceae_UCG-003, while concurrently reducing the relative abundance of potentially harmful bacteria such as Clostridium_sensu_stricto-1 and Escherichia-Shigella. It promotes the production of SCFAs, including acetate, isobutyrate, and butyrate. Furthermore, it activates G-protein-coupled receptors (GPR43/109A), inhibits the TLR4/MyD88 signaling pathway, strengthens the intestinal barrier function, and regulates the expression of related cytokines.

CONCLUSION

In summary, exogenous isobutyrate can be considered a promising feed additive for improving the intestinal microbiota and regulating intestinal health in piglets. © 2024 Society of Chemical Industry.

Oxygenation and intestinal perfusion and its association with perturbations of the early life gut microbiota composition of children with congenital heart disease

Background

Early life gut microbiota is known to shape the immune system and has a crucial role in immune homeostasis. Only little is known about composition and dynamics of the intestinal microbiota in infants with congenital heart disease (CHD) and potential influencing factors.

Methods

We evaluated the intestinal microbial composition of neonates with CHD (n = 13) compared to healthy controls (HC, n = 30). Fecal samples were analyzed by shotgun metagenomics. Different approaches of statistical modeling were applied to assess the impact of influencing factors on variation in species composition. Unsupervised hierarchical clustering of the microbial composition of neonates with CHD was used to detect associations of distinct clusters with intestinal tissue oxygenation and perfusion parameters, obtained by the "oxygen to see" (O2C) method.

Results

Overall, neonates with CHD showed an intestinal core microbiota dominated by the genera Enterococcus (27%) and Staphylococcus (20%). Furthermore, a lower abundance of the genera Bacteroides (8% vs. 14%), Parabacteroides (1% vs. 3%), Bifidobacterium (4% vs. 12%), and Escherichia (8% vs. 23%) was observed in CHD compared to HCs. CHD patients that were born by vaginal delivery showed a lower fraction of the genera Bacteroides (15% vs. 21%) and Bifidobacterium (7% vs. 22%) compared to HCs and in those born by cesarean section, these genera were not found at all. In infants with CHD, we found a significant impact of oxygen saturation (SpO2) on relative abundances of the intestinal core microbiota by multivariate analysis of variance (F[8,2] = 24.9, p = 0.04). Statistical modeling suggested a large proportional shift from a microbiota dominated by the genus Streptococcus (50%) in conditions with low SpO2 towards the genus Enterococcus (61%) in conditions with high SpO2. We identified three distinct compositional microbial clusters, corresponding neonates differed significantly in intestinal blood flow and global gut perfusion.

Conclusion

Early life differences in gut microbiota of CHD neonates versus HCs are possibly linked to oxygen levels. Delivery method may affect microbiota stability. However, further studies are needed to assess the effect of potential interventions including probiotics or fecal transplants on early life microbiota perturbations in neonates with CHD.

The gut-heart axis: a review of gut microbiota, dysbiosis, and cardiovascular disease development

Background

Cardiovascular diseases (CVDs) are a major cause of morbidity and mortality worldwide and there are strong links existing between gut health and cardiovascular health. Gut microbial diversity determines gut health. Dysbiosis, described as altered gut microbiota, causes bacterial translocations and abnormal gut byproducts resulting in systemic inflammation.

Objective

To review the current literature on the relationships between gut microbiota, dysbiosis, and CVD development, and explore therapeutic methods to prevent dysbiosis and support cardiovascular health.

Summary

Dysbiosis increases levels of pro-inflammatory substances while reducing those of anti-inflammatory substances. This accumulative inflammatory effect negatively modulates the immune system and promotes vascular dysfunction and atherosclerosis. High Firmicutes to Bacteroidetes ratios, high trimethylamine-n-oxide to short-chain fatty acid ratios, high indole sulfate levels, low cardiac output, and polypharmacy are all associated with worse cardiovascular outcomes. Supplementation with prebiotics and probiotics potentially alleviates some CVD risk. Blood and stool samples may be used in clinical practice to quantify and qualify gut bacterial ratios and byproducts, assess patients' risk for adverse cardiovascular outcomes, and track their gut health progress. Further research is required to set population-based cutoffs for normal and abnormal gut microbiota and byproduct ratios.

Study on the Mechanism of Bifidobacterium animalis subsp. lactis F1-3-2 Regulating Bile Acid Metabolism Through TMA-TMAO Pathway to Improve Atherosclerosis

Atherosclerosis is a major cause of cardiovascular disease (CVD). The trimethylamine (TMA)-trimethylamine N-oxide (TMAO) pathway is a key crossover pathway highly associated with diet, gut microbiome, and atherosclerosis. The Bifidobacterium animalis subsp. lactis F1-3-2 (Bif. animalis F1-3-2, No. CCTCCM2020832) was screened through in vitro and in vivo experiments in the early stage of this study with excellent lipid-lowering and anti-inflammatory function. By building an atherosclerosis model and focusing on TMAO, the specific mechanism of Bif. animalis F1-3-2 to improve atherosclerosis was explored. The study found that Bif. animalis F1-3-2 effectively improved the accumulation of aortic plaque in atherosclerotic mice. The strain improved lipid metabolism in serum and liver. It decreased the serum TMA and TMAO, regulated bile acid composition, participated in the farnesoid X receptor (FXR) pathway to improve lipid metabolism, and further reduced the aortic macrophage foam cell accumulation. In addition, the strain could improve the structure of the intestinal microbiome and reduce the proportion of Firmicutes and Bacteroidetes. The abundance of Turicibacter, Clostridium sensu stricto_1, and Romboutsia was reduced at the genus level. The differential microbiota is highly correlated with bile acid metabolism, which is speculated to be involved in ameliorating atherosclerotic lipid metabolism disorders.

Tryptophan Ameliorates Metabolic Syndrome by Inhibiting Intestinal Farnesoid X Receptor Signaling: The Role of Gut Microbiota-Bile Acid Crosstalk

Background and Aims: Metabolic syndrome (MS) is a progressive metabolic disease characterized by obesity and multiple metabolic disorders. Tryptophan (Trp) is an essential amino acid, and its metabolism is linked to numerous physiological functions and diseases. However, the mechanisms by which Trp affects MS are not fully understood. Methods and Results: In this study, experiments involving a high-fat diet (HFD) and fecal microbiota transplantation (FMT) were conducted to investigate the role of Trp in regulating metabolic disorders. In a mouse model, Trp supplementation inhibited intestinal farnesoid X receptor (FXR) signaling and promoted hepatic bile acid (BA) synthesis and excretion, accompanied by elevated levels of conjugated BAs and the ratio of non-12-OH to 12-OH BAs in hepatic and fecal BA profiles. As Trp alters the gut microbiota and the abundance of bile salt hydrolase (BSH)-enriched microbes, we collected fresh feces from Trp-supplemented mice and performed FMT and sterile fecal filtrate (SFF) inoculations in HFD-treated mice. FMT and SFF not only displayed lipid-lowering properties but also inhibited intestinal FXR signaling and increased hepatic BA synthesis. This suggests that the gut microbiota play a beneficial role in improving BA metabolism through Trp. Furthermore, fexaramine (a gut-specific FXR agonist) reversed the therapeutic effects of Trp, suggesting that Trp acts through the FXR signaling pathway. Finally, validation in a finishing pig model revealed that Trp improved lipid metabolism, enlarged the hepatic BA pool, and altered numerous glycerophospholipid molecules in the hepatic lipid profile. Conclusion: Our studies suggest that Trp inhibits intestinal FXR signaling mediated by the gut microbiota-BA crosstalk, which in turn promotes hepatic BA synthesis, thereby ameliorating MS.

Mapping the gut microbial structural variations in healthy aging within the Chinese population

Mapping gut microbial structural variants (SVs) during human aging may provide fundamental knowledge and mechanistic understanding of the gut microbiome's relationship with healthy aging. We characterize gut microbial SVs from 3,230 Chinese participants, identifying key SVs associated with aging, healthy aging, and age-related chronic diseases. Our findings reveal a pattern of copy number loss in aging-related SVs, with 35 core SVs consistently detected. Additionally, eight SVs distinguish healthy from unhealthy aging, regardless of age. Notably, a 3-kbp deletion SV of Bifidobacterium pseudocatenulatum, encoding plant polysaccharide degradation, is regulated by plant-based diet and contributes to healthy aging through bile acid metabolism. Our analysis also connects SVs to age-related diseases, such as chronic kidney disease, via genes in the methionine-homocysteine pathway. This study deepens our understanding of the gut microbiome's role in aging and could inform future efforts to enhance lifespan and healthspan.

Feeding intolerance after pediatric cardiac surgery is associated with dysbiosis, barrier dysfunction, and reduced short-chain fatty acids

Congenital heart disease (CHD) is the most common birth defect, occurring in roughly 40,000 U.S. births annually. Malnutrition and feeding intolerance (FI) in CHD range from 30% to 42% and are associated with longer hospitalization and increased mortality. Cardiopulmonary bypass (CPB) required for surgical repair of CHD induces a systemic inflammatory response worsening intestinal dysbiosis and leading to intestinal epithelial barrier dysfunction (EBD), possibly contributing to postoperative FI. The objective of this study was to determine the relationship of postoperative FI with intestinal microbiome, short-chain fatty acids (SCFAs), and EBD in pediatric CHD after cardiac surgery. This was a prospective study of patients aged 0-15 years undergoing cardiac surgery with CPB. Samples were collected preoperatively and postoperatively to evaluate the gut microbiome, plasma EBD markers, short-chain fatty acids (SCFAs), and plasma cytokines. Clinical data were collected to calculate a FI score and evaluate patient status postoperatively. We enrolled 26 CPB patients and identified FI (n = 13). Patients with FI had unique microbial shifts with the reduced SCFA-producing organisms Rothia, Clostridium innocuum, and Intestinimonas. Patients who developed FI had associated elevations in the plasma EBD markers claudin-2 (P < 0.05), claudin-3 (P < 0.01), and fatty acid binding protein (P < 0.01). Patients with FI had reduced plasma and stool SCFAs. Mediation analysis showed the microbiome functional shift was associated with reductions in stool butyric and propionic acid in patients with FI. In conclusion, we provide novel evidence that intestinal dysbiosis, markers of EBD, and SCFA depletion are associated with FI. These data will help identify mechanisms and therapeutics to improve clinical outcomes following pediatric cardiac surgery.NEW & NOTEWORTHY Feeding intolerance contributes to postoperative morbidity following pediatric cardiac surgery. The intestinal microbiome and milieu play a vital role in gut function. Short-chain fatty acids are gut and cardioprotective metabolites produced by commensal bacteria and help maintain appropriate barrier function. Depletion of these metabolites and barrier dysfunction contribute to postoperative feeding intolerance following cardiac surgery. Identifying mechanistic targets to improve the intestinal milieu with the goal of improved nutrition and clinical outcomes is critical.

Microbiome and Growth in Infants with Congenital Heart Disease

OBJECTIVE

To profile the gut microbiome (GM) in infants with congenital heart disease (CHD) undergoing cardiac surgery compared with matched infants and to investigate the association with growth (weight, length, and head circumference).

STUDY DESIGN

A prospective study in the cardiac intensive care unit at Children's Healthcare of Atlanta and newborn nursery within the Emory Healthcare system. Characteristics including weight, length, head circumference, and surgical variables were collected. Fecal samples were collected presurgery (T1), postsurgery (T2), and before discharge (T3), and once for controls. 16 small ribosomal RNA subunit V4 gene was sequenced from fecal samples and classified into taxonomy using Silva v138.

RESULTS

There were 34 children with CHD (cases) and 34 controls. Cases had higher alpha-diversity, and beta-diversity showed significant dissimilarities compared with controls. GM was associated with lower weight and smaller head circumference (z-score < 2). Lower weight was associated with less Acinetobacter, Clostridioides, Parabacteroides, and Escherichia-Shigella. Smaller head circumference with more Veillonella, less Acinetobacter, and less Parabacteroides.

CONCLUSIONS

Significant differences in GM diversity and abundance were observed between infants with CHD and control infants. Lower weight and smaller head circumference were associated with distinct GM patterns. Further study is needed to understand the longitudinal effect of microbial dysbiosis on growth in children with CHD.

Integrated multi-omics analysis of the microbial profile characteristics associated with pulmonary arterial hypertension in congenital heart disease

Dysregulation of immune and inflammatory cells around blood vessels and metabolic dysfunction are key mechanisms in the development of pulmonary arterial hypertension (PAH). The homeostasis of the human microbiome plays a crucial role in regulating immune responses and the progression of diseases. For pulmonary arterial hypertension associated with congenital heart disease involving body-lung shunt (PAH-CHD), the potential impact of the microbiome on the "gut-lung axis" remains underexplored. This study recruited 15 healthy individuals and 15 patients with pulmonary arterial hypertension due to congenital heart disease from Fuwai Yunnan Hospital, Chinese Academy of Medical Sciences, and Kunming Children's Hospital. We performed differential analyses of metabolites and microbiota from both the gut and lower respiratory tract for these two groups. The goal was to investigate the "gut-lung axis" microbiome and metabolome profiles in children with PAH-CHD and to analyze the interrelationships between these profiles. Ultimately, we aim to propose the potential value of these profiles in aiding diagnosis. The results indicated that the gut and pulmonary microbiota of children with PAH-CHD are characterized by an increased abundance of beneficial symbionts, which are closely linked to changes in the metabolome. Metabolite functional enrichment analysis revealed energy metabolism reprogramming in the PAH-CHD group, with active metabolic pathways associated with bile acid secretion and carnitine homeostasis. Moreover, the differential expression of metabolites was correlated with right heart function and growth development.IMPORTANCEPrevious studies have primarily focused on the relationship between the gut microbiome and PAH. However, the impact of microbial homeostasis on the progression of PAH-CHD from the perspective of the gut-lung axis has not been adequately elucidated. Our study utilizes an integrated multi-omics approach to report on the differential characteristics of gut and lung microbiota between children with PAH-CHD and reference subjects. We found that microbiota influence the pathological changes and disease manifestations of PAH-CHD through their metabolic activity. Additionally, alterations in metabolites impact the microbial ecological structure. Our findings suggest that modulating the microbiome composition may have positive implications for maintaining and regulating the immune environment and pathological progression of PAH-CHD.

The current state of the problem of intestinal microbiota according to pediatricians

The mechanisms of formation of the intestinal microbiota, its influence on the health of the child, participation in physiological and pathological processes are considered. Microorganisms enter the body of the fetus in utero, then the newborn child receives the microflora from the mother during childbirth. The results of molecular genetic studies indicate that the process of microbial colonization of a child is determined by the characteristics of nutrition. Of great importance in the formation of normal microflora belongs to breastfeeding. The gut microbiota interacts with various parts of the body, influencing the pathogenesis of many local and systemic diseases. The most important mechanisms for the formation of diseases in children depending on anomalies in the structure of the microbiome are considered. Understanding the processes of formation of intestinal microflora allows us to develop effective methods for the prevention and correction of microecological and motor disorders in the age aspect.

Gut Microbiome in Children with Congenital Heart Disease After Cardiopulmonary Bypass Surgery (GuMiBear Study)

The gut microbiome of infants with congenital heart disease (CHD) undergoing cardiopulmonary bypass surgery (CPB) is at risk of profound alteration. The aim of this study was to examine the gut microbiome pre- and post-bypass surgery to explore potential implications of altered gut biodiversity. A prospective cohort study involving infants with CHD who underwent CPB was performed. Faecal samples were collected from infants alongside the collection of demographic and clinical data in order to examine gut microbiome changes before and after surgery. 16S rRNA sequencing analysis was performed on DNA isolated from stool samples to determine changes in gut microbiome composition. Thirty-three patients were recruited, with samples from thirteen of these available for final analysis. Compared with healthy, matched controls, at a genus level, pre-operative samples for infants with CHD demonstrated a higher relative abundance of Escherichia-Shigella (31% vs 2-6%) and a lower relative abundance of Bifidobacterium (13% vs 40-60%). In post-operative samples, the relative abundance of Escherichia-Shigella (35%), Enterococcus (11%), Akkermansia (6%), and Staphylococcus (5%) were higher than pre-op samples. One infant developed post-operative necrotising-enterocolitis (NEC). They displayed a marked abundance of the Enterococcus (93%) genus pre-operatively. This study demonstrates that infants with CHD have an altered gut microbiome when compared with healthy controls and there might be a possible link between an abundance of virulent species and NEC.

Bacillus siamensis Targeted Screening from Highly Colitis-Resistant Pigs Can Alleviate Ulcerative Colitis in Mice

Ulcerative colitis (UC) is often accompanied by intestinal inflammation and disruption of intestinal epithelial structures, which are closely associated with changes in the intestinal microbiota. We previously revealed that Min pigs, a native Chinese breed, are more resistant to dextran sulfate sodium (DSS)-induced colitis than commercial Yorkshire pigs. Characterizing the microbiota in Min pigs would allow identification of the core microbes that confer colitis resistance. By analyzing the microbiota linked to the disease course in Min and Yorkshire pigs, we observed that Bacillus spp. were enriched in Min pigs and positively correlated with pathogen resistance. Using targeted screening, we identified and validated Bacillus siamensis MZ16 from Min pigs as a bacterial species with biofilm formation ability, superior salt and pH tolerance, and antimicrobial characteristics. Subsequently, we administered B. siamensis MZ16 to conventional or microbiota-deficient BALB/c mice with DSS-induced colitis to assess its efficacy in alleviating colitis. B. siamensis MZ16 partially counteracted DSS-induced colitis in conventional mice, but it did not mitigate DSS-induced colitis in microbiota-deficient mice. Further analysis revealed that B. siamensis MZ16 administration improved intestinal ecology and integrity and immunological barrier function in mice. Compared to the DSS-treated mice, mice preadministered B. siamensis MZ16 exhibited improved relative abundance of potentially beneficial microbes (Lactobacillus, Bacillus, Christensenellaceae R7, Ruminococcus, Clostridium, and Eubacterium), reduced relative abundance of pathogenic microbes (Escherichia-Shigella), and maintained colonic OCLN and ZO-1 levels and IgA and SIgA levels. Furthermore, B. siamensis MZ16 reduced proinflammatory cytokine levels by reversing NF-κB and MAPK pathway activation in the DSS group. Overall, B. siamensis MZ16 from Min pigs had beneficial effects on a colitis mouse model by enhancing intestinal barrier functions and reducing inflammation in a gut microbiota-dependent manner.

Lactobacillus plantarum 24-7 improves postoperative bloating and hard stools by modulating intestinal microbiota in patients with congenital heart disease: a randomized controlled trial

Gastrointestinal symptoms are a common postoperative complication in patients with congenital heart disease (CHD), affecting their postoperative recovery. Probiotic intervention may be a promising therapeutic approach to alleviate postoperative gastrointestinal symptoms. This study aimed to evaluate the potential of Lactobacillus plantarum 24-7 (L. plantarum 24-7) in mitigating postoperative gastrointestinal symptoms and promoting patient recovery. Adult CHD patients scheduled for surgical intervention were recruited. One hundred and twenty patients were randomized and received L. plantarum or placebo intervention twice daily for ten days. Gastrointestinal symptoms were assessed utilizing the Gastrointestinal Symptom Rating Scale (GSRS). Various postoperative variables were analyzed across both groups. Alterations in gut microbiota were evaluated through 16S rRNA sequencing. 112 patients completed the study, with 55 in the probiotic group and 57 in the placebo group. While the disparity in overall postoperative GSRS scores between the two groups did not reach statistical significance (P = 0.067), marked differences were observed in bloating (P = 0.004) and hard stool (P = 0.030) scores. Furthermore, individuals within the probiotic group exhibited lower postoperative neutrophil counts (P = 0.007) and concurrently higher lymphocyte counts (P = 0.001). Variations in the diversity and composition of postoperative gut microbiota were discerned between the probiotic and placebo groups. Remarkably, no probiotic-related adverse events were documented. Supplementation with L. plantarum was well-tolerated and demonstrated partial efficacy in ameliorating gastrointestinal symptoms in postoperative CHD patients. Modulating the gut microbiota may be a potential mechanism by which L. plantarum exerts clinical benefits.

Advancing lifelong precision medicine for cardiovascular diseases through gut microbiota modulation

The gut microbiome is known as the tenth system of the human body that plays a vital role in the intersection between health and disease. The considerable inter-individual variability in gut microbiota poses both challenges and great prospects in promoting precision medicine in cardiovascular diseases (CVDs). In this review, based on the development, evolution, and influencing factors of gut microbiota in a full life circle, we summarized the recent advances on the characteristic alteration in gut microbiota in CVDs throughout different life stages, and depicted their pathological links in mechanism, as well as the highlight achievements of targeting gut microbiota in CVDs prevention, diagnosis and treatment. Personalized strategies could be tailored according to gut microbiota characteristics in different life stages, including gut microbiota-blood metabolites combined prediction and diagnosis, dietary interventions, lifestyle improvements, probiotic or prebiotic supplements. However, to fulfill the promise of a lifelong cardiovascular health, more mechanism studies should progress from correlation to causality and decipher novel mechanisms linking specific microbes and CVDs. It is also promising to use the burgeoning artificial intelligence and machine learning to target gut microbiota for developing diagnosis system and screening for new therapeutic interventions.

Changes of Intestinal Flora and the Effect on Intestinal Function in Infants With Ventricular Septal Defect After Cardiopulmonary Bypass Surgery

This study aimed to investigate the changes in intestinal flora in infants with ventricular septal defect (VSD) after cardiopulmonary bypass (CPB) surgery and their potential relationship with postoperative gastrointestinal function recovery. Fecal samples of 20 infants with VSD were collected before and after CPB surgery at our hospital from September 2021 to March 2022. 16S rRNA was used to detect and analyze the fecal samples. The most abundant intestinal microbes in the preoperative intestinal flora were Enterococcus (37.14%), Bifidobacterium (20.71%), Shigella (8.15%), Streptococcus (5.19%), Lactobacillus (3.7%), Rothia (2.22%). However, the most abundant intestinal microbes in the postoperative intestinal flora were Enterococcus (49.63%), Bifidobacterium (12.59%), Shigella (10.37%), Streptococcus (8.14%), Rothia (4.43%). The diversity and species richness of intestinal flora after CPB surgery were significantly lower than those preoperatively. The intestinal Enterococcus content in patients with postoperative gastrointestinal dysfunction was significantly higher than that in patients without gastrointestinal dysfunction (P < 0.05). Intestinal Bifidobacterium content in patients with postoperative gastrointestinal dysfunction was significantly lower than that in patients without gastrointestinal dysfunction (P < 0.05). After surgery, the content of intestinal Enterococcus was negatively correlated with the full feeding time, and the content of intestinal Bifidobacterium was positively correlated with full feeding time. After CPB surgery, the diversity and richness of intestinal flora decreased, intestinal pathogenic bacteria increased, and beneficial intestinal bacteria decreased. An increase in Enterococcus and decrease in Bifidobacterium can increase the incidence of gastrointestinal dysfunction and prolong the recovery time of gastrointestinal function.

Does the Human Gut Virome Contribute to Host Health or Disease?

The human gastrointestinal (GI) tract harbors eukaryotic and prokaryotic viruses and their genomes, metabolites, and proteins, collectively known as the "gut virome". This complex community of viruses colonizing the enteric mucosa is pivotal in regulating host immunity. The mechanisms involved in cross communication between mucosal immunity and the gut virome, as well as their relationship in health and disease, remain largely unknown. Herein, we review the literature on the human gut virome's composition and evolution and the interplay between the gut virome and enteric mucosal immunity and their molecular mechanisms. Our review suggests that future research efforts should focus on unraveling the mechanisms of gut viruses in human homeostasis and pathophysiology and on developing virus-prompted precision therapies.

Gut microbial structural variation associates with immune checkpoint inhibitor response

The gut microbiota may have an effect on the therapeutic resistance and toxicity of immune checkpoint inhibitors (ICIs). However, the associations between the highly variable genomes of gut bacteria and the effectiveness of ICIs remain unclear, despite the fact that merely a few gene mutations between similar bacterial strains may cause significant phenotypic variations. Here, using datasets from the gut microbiome of 996 patients from seven clinical trials, we systematically identify microbial genomic structural variants (SVs) using SGV-Finder. The associations between SVs and response, progression-free survival, overall survival, and immune-related adverse events are systematically explored by metagenome-wide association analysis and replicated in different cohorts. Associated SVs are located in multiple species, including Akkermansia muciniphila, Dorea formicigenerans, and Bacteroides caccae. We find genes that encode enzymes that participate in glucose metabolism be harbored in these associated regions. This work uncovers a nascent layer of gut microbiome heterogeneity that is correlated with hosts' prognosis following ICI treatment and represents an advance in our knowledge of the intricate relationships between microbiota and tumor immunotherapy.

From heart to gut: Exploring the gut microbiome in congenital heart disease

Congenital heart disease (CHD) is a prevalent birth defect and a significant contributor to childhood mortality. The major characteristics of CHD include cardiovascular malformations and hemodynamical disorders. However, the impact of CHD extends beyond the circulatory system. Evidence has identified dysbiosis of the gut microbiome in patients with CHD. Chronic hypoxia and inflammation associated with CHD affect the gut microbiome, leading to alterations in its number, abundance, and composition. The gut microbiome, aside from providing essential nutrients, engages in direct interactions with the host immune system and indirect interactions via metabolites. The abnormal gut microbiome or its products can translocate into the bloodstream through an impaired gut barrier, leading to an inflammatory state. Metabolites of the gut microbiome, such as short-chain fatty acids and trimethylamine N-oxide, also play important roles in the development, treatment, and prognosis of CHD. This review discusses the role of the gut microbiome in immunity, gut barrier, neurodevelopment, and perioperative period in CHD. By fostering a better understanding of the cross-talk between CHD and the gut microbiome, this review aims to contribute to improve clinical management and outcomes for CHD patients.

The Bacterial Oral Microbiome in Children with Congenital Heart Disease: An Extensive Review

Children with congenital heart disease have poorer oral health compared with healthy children. Oral diseases, such as dental caries and gingivitis, are associated with the oral microbiome. The objective of this review was to find evidence of differences in the bacterial colonization of the oral cavity of children with congenital heart disease (CHD) versus healthy children. A literature review was conducted according to predetermined criteria, including the need for controlled clinical trials. Half of the 14 studies that met the inclusion criteria reported significant differences in bacterial colonization in children with congenital heart disease. A variety of influencing factors were discussed. There is some evidence for alterations in the oral microflora as a result of physiopathological and treatment-related factors in children with CHD, but additional research is required to validate these findings.

Characteristics of the pulmonary microbiota in patients with mild and severe pulmonary infection

Background

Lung infection is a global health problem associated with high morbidity and mortality and increasing rates of hospitalization. The correlation between pulmonary microecology and infection severity remains unclear. Therefore, the purpose of this study was to investigate the differences in lung microecology and potential biomarkers in patients with mild and severe pulmonary infection.

Method

Patients with pulmonary infection or suspected infection were divided into the mild group (140 cases) and the severe group (80 cases) according to pneomonia severity index (PSI) scores. Here, we used metagenomic next-generation sequencing (mNGS) to detect DNA mainly from bronchoalveolar lavage fluid (BALF) collected from patients to analyze changes in the lung microbiome of patients with different disease severity.

Result

We used the mNGS to analyze the pulmonary microecological composition in patients with pulmonary infection. The results of alpha diversity and beta diversity analysis showed that the microbial composition between mild and severe groups was similar on the whole. The dominant bacteria were Acinetobacter, Bacillus, Mycobacterium, Staphylococcus, and Prevotella, among others. Linear discriminant analysis effect size (LEfSe) results showed that there were significant differences in virus composition between the mild and severe patients, especially Simplexvirus and Cytomegalovirus, which were prominent in the severe group. The random forest model screened 14 kinds of pulmonary infection-related pathogens including Corynebacterium, Mycobacterium, Streptococcus, Klebsiella, and Acinetobacter. In addition, it was found that Rothia was negatively correlated with Acinetobacter, Mycobacterium, Bacillus, Enterococcus, and Klebsiella in the mild group through co-occurrence network, while no significant correlation was found in the severe group.

Conclusion

Here, we describe the composition and diversity of the pulmonary microbiome in patients with pulmonary infection. A significant increase in viral replication was found in the severe group, as well as a significant difference in microbial interactions between patients with mild and severe lung infections, particularly the association between the common pathogenic bacteria and Rothia. This suggests that both pathogen co-viral infection and microbial interactions may influence the course of disease. Of course, more research is needed to further explore the specific mechanisms by which microbial interactions influence disease severity.

Gut Phageome-An Insight into the Role and Impact of Gut Microbiome and Their Correlation with Mammal Health and Diseases

The gut microbiota, including bacteria, archaea, fungi, and viruses, compose a diverse mammalian gut environment and are highly associated with host health. Bacteriophages, the viruses that infect bacteria, are the primary members of the gastrointestinal virome, known as the phageome. However, our knowledge regarding the gut phageome remains poorly understood. In this review, the critical role of the gut phageome and its correlation with mammalian health were summarized. First, an overall profile of phages across the gastrointestinal tract and their dynamic roles in shaping the surrounding microorganisms was elucidated. Further, the impacts of the gut phageome on gastrointestinal fitness and the bacterial community were highlighted, together with the influence of diets on the gut phageome composition. Additionally, new reports on the role of the gut phageome in the association of mammalian health and diseases were reviewed. Finally, a comprehensive update regarding the advanced phage benchwork and contributions of phage-based therapy to prevent/treat mammalian diseases was provided. This study provides insights into the role and impact of the gut phagenome in gut environments closely related to mammal health and diseases. The findings provoke the potential applications of phage-based diagnosis and therapy in clinical and agricultural fields. Future research is needed to uncover the underlying mechanism of phage-bacterial interactions in gut environments and explore the maintenance of mammalian health via phage-regulated gut microbiota.

Human Milk Feeding and Direct Breastfeeding Improve Outcomes for Infants With Single Ventricle Congenital Heart Disease: Propensity Score-Matched Analysis of the NPC-QIC Registry

Background Infants with single ventricle congenital heart disease undergo 3 staged surgeries/interventions, with risk for morbidity and mortality. We estimated the effect of human milk (HM) and direct breastfeeding on outcomes including necrotizing enterocolitis, infection-related complications, length of stay, and mortality. Methods and Results We analyzed the National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) registry (2016-2021), examining HM/breastfeeding groups during stage 1 and stage 2 palliations. We calculated propensity scores for feeding exposures, then fitted Poisson and logistic regression models to compare outcomes between propensity-matched cohorts. Participants included 2491 infants (68 sites). Estimates for all outcomes were better in HM/breastfeeding groups. Infants fed exclusive HM before stage 1 palliation (S1P) had lower odds of preoperative necrotizing enterocolitis (odds ratio [OR], 0.37 [95% CI, 0.17-0.84]; P=0.017) and shorter S1P length of stay (rate ratio [RR], 0.87 [95% CI, 0.78-0.98]; P=0.027). During the S1P hospitalization, infants with high HM had lower odds of postoperative necrotizing enterocolitis (OR, 0.28 [95% CI, 0.15-0.50]; P<0.001) and sepsis (OR, 0.29 [95% CI, 0.13-0.65]; P=0.003), and shorter S1P length of stay (RR, 0.75 [95% CI, 0.66-0.86]; P<0.001). At stage 2 palliation, infants with any HM (RR, 0.82 [95% CI, 0.69-0.97]; P=0.018) and any breastfeeding (RR, 0.71 [95% CI, 0.57-0.89]; P=0.003) experienced shorter length of stay. Conclusions Infants with single ventricle congenital heart disease in high-HM and breastfeeding groups experienced multiple significantly better outcomes. Given our findings of improved health, strategies to increase the rates of HM/breastfeeding in these patients should be implemented. Future research should replicate these findings with granular feeding data and in broader congenital heart disease populations, and should examine mechanisms (eg, HM components, microbiome) by which HM/breastfeeding benefits these infants.

Human milk feeding and direct breastfeeding improve outcomes for infants with single ventricle congenital heart disease: Propensity score matched analysis of the NPC-QIC registry

Background

Infants with single ventricle (SV) congenital heart disease (CHD) undergo three staged surgeries/interventions, with risk for morbidity and mortality. We estimated the effect of human milk (HM) and direct breastfeeding (BF) on outcomes including necrotizing enterocolitis (NEC), infection-related complications, length of stay (LOS), and mortality.

Methods

We analyzed the National Pediatric Cardiology Quality Improvement Collaborative registry (2016-2021), examining HM/BF groups during stage 1 (S1P) and stage 2 (S2P) palliations. We calculated propensity scores for feeding exposures, then fitted Poisson and logistic regression models to compare outcomes between propensity-matched cohorts.

Results

Participants included 2491 infants (68 sites). Estimates for all outcomes were better in HM/BF groups. Infants fed exclusive HM before S1P had lower odds of preoperative NEC (OR=0.37, 95% CI=0.17-0.84, p=0.017) and shorter S1P LOS (RR=0.87, 0.78-0.98, p=0.027). During the S1P hospitalization, infants with high HM had lower odds of postoperative NEC (OR=0.28, 0.15-0.50, p<0.001) and sepsis (0.29, 0.13-0.65, p=0.003), and shorter S1P LOS (RR=0.75, 0.66-0.86, p<0.001). At S2P, infants with any HM (0.82, 0.69-0.97, p=0.018) and any BF (0.71, 0.57-0.89, p=0.003) experienced shorter LOS.

Conclusions

Infants with SV CHD in high HM and BF groups experienced multiple significantly better outcomes. Given our findings of improved health, strategies to increase the rates of HM/BF in these patients should be implemented. Future research should replicate these findings with granular feeding data and in broader CHD populations, and should examine mechanisms (eg, HM components; microbiome) by which HM/BF benefits these infants.

Clinical Perspective

What is new?: This is the first large, multisite study examining the impact of human milk and breastfeeding on outcomes for infants with single ventricle congenital heart disease.All outcome estimates were better in high human milk and breastfeeding groups, with significantly lower odds of necrotizing enterocolitis, sepsis, and infection-related complications; and significantly shorter length of stay at both the neonatal stage 1 palliation and the subsequent stage 2 palliation.All estimates of all-cause mortality were substantially lower in human milk and breastfeeding groups, with clinically important estimates of 75%-100% lower odds of mortality in direct breastfeeding groups.What are the clinical implications?: There is a critical need for improved, condition-specific lactation support to address the low prevalence of human milk and breastfeeding for infants with single ventricle congenital heart disease.Increasing the dose and duration of human milk and direct breastfeeding has strong potential to substantially improve the health outcomes of these vulnerable infants.