Differences In Gut Microbiota Composition Research Articles

Distinct Gut Microbiome Induced by Different Feeding Regimes in Weaned Piglets.

It is well accepted that the gut microbiota of breast-fed (BF) and formula-fed (FF) infants are significantly different. However, there is still a limited number of studies comparing the gut microbiota of BF and FF piglets, despite increasing numbers of FF piglets in the modern pig industry. The present study identified the differences in gut microbiota composition between BF- and FF-weaned Rongchang piglets at 30 days old, using pair-end sequencing on the Illumina HiSeq 2500 platform. The BF piglets had lower microbiota diversities than FF piglets (p < 0.05), and the community structures were well clustered as a result of each feeding pattern. Firmicutes and Bacteroidetes represented the most dominant phyla, and Ruminococcus, Prevotella, and Gemmiger were prominent genera in all piglets. Ruminococcus, Prevotella, Oscillospira, Eubacterium, Gemmiger, Dorea, and Lactobacillus populations were significantly higher, while Treponema and Coprococcus were significantly lower in BF piglets compared to FF piglets (p < 0.05). The metabolism pathways in the BF piglets were significantly different from FF piglets, which included carbohydrate and amino acid metabolism (p < 0.05). In addition, the top 10 abundance of microbiota were more or less significantly associated with the two phenotypes (p < 0.05). Collectively, these findings provide probable explanations for the importance of BF in neonates and support a theoretical basis for feeding regimes in indigenous Chinese piglets.

523 MITOAKAP PLAY A ROLE IN THE PROGRESSION TOWARDS HEART FAILURE MODULATING GUT INTEGRITY AND COMPOSITION DURING AGING

Abstract Background Mitochondrial A-kinase anchoring proteins (mitoAKAP) encoded by the Akap1 gene promote Protein Kinase A mitochondrial targeting, regulating mitochondrial structure and function, reactive oxygen species production and cardiomyocyte survival. Whether mitoAKAP levels play a role in cardiac aging, gut barrier integrity and gut microbiota composition is currently unknown. Purpose The aim of this study was to highlight the complex interplay between cardiac dysfunction, gut barrier integrity, gut microbiota composition and aging in young (6-month-old, 6m) and old (24-month-old, 24m) wild type (wt) and Akap1 heterozygous mice (Akap1+/-). Methods Cardiac function was noninvasively analyzed by echocardiography in 6m and 24m wt and Akap1+/- mice. Gut microbial DNA was extracted and gut microbiota composition was analyzed by Illumina Mi-Seq analysis. Bioinformatics analysis was carried out to identify major intestinal populations. Alpha diversity within each sample was determined, and then analyzed according to genotype and age; then, inter-sample diversity was determined. For each dataset, we used UniFrac to calculate the differences between microbial communities based on phylogenetic distance between taxa sets in a phylogenetic tree. Bioinformatics analyses were performed using the analysis of similarities (ANOSIM). To evaluate the role of mitoAKAPs in intestinal permeability, we analyzed intestinal junction proteins expression levels in colon samples of all groups. Variance analysis was performed to determine significance among the groups. Results Partial loss of Akap1 accelerated the progression of cardiac dysfunction in 24m mice, as demonstrated by a significantly lower % fractional shortening (%FS) compared to 24m wt mice (%FS, wt 6m: 60±3; Akap1-/+ 6m: 58±5; wt 24m: 49±6*; Akap1-/+ 24m: 39±12*§; *p<0.05 vs. wt 6m; §p<0.05 vs. wt 24m). In 24m Akap1+/- mice, aging was associated to enhanced colon permeability, as shown by reduced levels of Ocln and Tjp1 mRNA expression. A principal coordinate analysis of fecal samples based on their unweighted UniFrac distances revealed that samples from Akap1+/- 24m mice cluster apart from wt 24m samples, suggesting that Akap1+/- 24m mice exhibit a different assortment of microbial communities. This observation was supported by ANOSIM R statistic that revealed significant differences in gut microbiota composition between wt and Akap1+/- 24m mice (ANOSIM R=0.475, P=0.023), while no significant differences in bacterial assortment were identified between wt and Akap1+/- 6m mice. We analyzed the differences in abundance of all 2,042 Operational Taxonomic Units (OTUs) between age-matched wt and Akap1+/-. We identified 10 OTUs differently represented in wt and Akap1+/- 6m mice, while a bigger set of bacterial OTUs (19) were different between wt and Akap1+/-24m mice. Consistent with previous results in patients with heart failure, we identified Clostridiales, Blautia producta and R. Torques among differently regulated species. These results are in accordance with previous data on patients with heart failure (HF). Conclusion Partial Akap1 deletion plays an important role in the progression toward HF and modulates colon permeability and gut microbiota composition during aging. This work highlights the complex interplay between gut microbiota and development of cardiac dysfunction, and characterization of these processes might lead to the development of new diagnostic and therapeutic approaches for cardiac dysfunction.

Lactobacillus rhamnosus GG protects against atherosclerosis by improving ketone body synthesis.

Atherosclerosis (AS) is a major cause of death and morbidity worldwide. There is an increasing amount of evidence that the gut microbiota plays an important role in disorders associated with lipid metabolism, such as AS, and alterations in the composition of the gut microbiota and its metabolic potential have been identified as contributing factors in the development of AS. Recently, probiotics have attracted great interest for their excellent cholesterol-lowering ability, their capacity to improve vascular endothelial function, and their participation in the remodeling of the intestinal flora to prevent AS. The incidental findings of our other study suggest that probiotic Lactobacillus rhamnosus GG may be associated with slowing the progression of AS. Thus, we delivered strain GG into mice by oral feeding and found that strain GG could effectively inhibit AS plaque generation. We analyzed the differences in gut microbiota composition and the peripheral blood metabolome in mice after oral feeding of strain GG by 16S DNA sequencing and untargeted metabolomics, respectively. The results showed that strain GG changed the composition of the gut microbiota in mice fed a high-fat diet; elevated the abundance of beneficial bacteria, such as Bilophila and Alistipes, and decreased the abundance of harmful bacteria, such as Deltaproteobacteria. The results of enrichment analysis of the gut microbiota and the peripheral blood metabolome both indicated that the antiatherosclerotic effect of strain GG might be associated with the biosynthesis pathway of ketone bodies. In addition, strain GG attenuated endothelial injury and elevated peripheral blood ketone body content in mice but did not significantly affect low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) content. In conclusion, our study provides new evidence that strain GG slows the progression of AS, which may be associated with its improvement of the gut microbiome and peripheral blood metabolome, its ability to increase the abundance of beneficial bacteria, and its participation in unsaturated fatty acid and ketone body synthesis and degradation. KEY POINTS: • L. rhamnosus GG attenuated endothelial injury and atherosclerotic plaque formation • L. rhamnosus GG elevated the abundance of beneficial bacteria • L. rhamnosus GG elevated peripheral blood ketone body content in mice.

Changes and significance of gut microbiota in children with focal epilepsy before and after treatment.

To better understand the alterations in gut microbiota and metabolic pathways in children with focal epilepsy, and to further investigate the changes in the related gut microbiota and metabolic pathways in these children before and after treatment. Ten patients with newly diagnosed focal epilepsy in Hunan Children's Hospital from April, 2020 to October, 2020 were recruited into the case group. The case group was further divided into a pre-treatment subgroup and a post-treatment subgroup. Additionally, 14 healthy children of the same age were recruited into a control group. The microbial communities were analyzed using 16s rDNA sequencing data. Metastas and LEfSe were used to identify different bacteria between and within groups. The Kyoto Encyclopedia of Genes and Genomes database was used to KEGG enrichment analysis. There were significant differences in α diversity among the pre-treatment, post-treatment, and control groups. Besides, the differences in gut microbiota composition in 3 groups were identified by principal co-ordinates analysis (PCoA), which showed a similar composition of the pre-treatment and post-treatment subgroups. At the phyla level, the relative abundance of Actinobacteria in the pre-treatment subgroup was significantly higher than that in the control group, which decreased significantly after 3 months of treatment and showed no significant difference between the control group. In terms of the genus level, Escherichia/Shigella, Streptococcus, Collinsella, and Megamonas were enriched in the pre-treatment subgroup, while Faecalibacterium and Anaerostipes were enriched in the control group. The relative abundance of Escherichia/Shigella, Streptococcus, Collinsella, and Megamonas was reduced significantly after a three-month treatment. Despite some genera remaining significantly different between the post-treatment subgroup and control group, the number of significantly different genera decreased from 9 to 4 through treatment. Notably, we found that the carbohydrate metabolism, especially succinate, was related to focal epilepsy. Children with focal epilepsy compared with healthy controls were associated with the statistically significant differences in the gut microbiota and carbohydrate metabolism. The differences were reduced and the carbohydrate metabolism improved after effective treatment. Our research may provide new directions for understanding the role of gut microbiota in the pathogenesis of focal epilepsy and better alternative treatments.

Cytomegalovirus infection disrupts the influence of short-chain fatty acid producers on Treg/Th17 balance

BackgroundBoth the gut microbiota and chronic viral infections have profound effects on host immunity, but interactions between these influences have been only superficially explored. Cytomegalovirus (CMV), for example, infects approximately 80% of people globally and drives significant changes in immune cells. Similarly, certain gut-resident bacteria affect T-cell development in mice and nonhuman primates. It is unknown if changes imposed by CMV on the intestinal microbiome contribute to immunologic effects of the infection.ResultsWe show that rhesus cytomegalovirus (RhCMV) infection is associated with specific differences in gut microbiota composition, including decreased abundance of Firmicutes, and that the extent of microbial change was associated with immunologic changes including the proliferation, differentiation, and cytokine production of CD8+ T cells. Furthermore, RhCMV infection disrupted the relationship between short-chain fatty acid producers and Treg/Th17 balance observed in seronegative animals, showing that some immunologic effects of CMV are due to disruption of previously existing host-microbe relationships.ConclusionsGut microbes have an important influence on health and disease. Diet is known to shape the microbiota, but the influence of concomitant chronic viral infections is unclear. We found that CMV influences gut microbiota composition to an extent that is correlated with immunologic changes in the host. Additionally, pre-existing correlations between immunophenotypes and gut microbes can be subverted by CMV infection. Immunologic effects of CMV infection on the host may therefore be mediated by two different mechanisms involving gut microbiota.CSBmPNqVbm-wbH_WVfXSdnVideo

Dietary EVOO Polyphenols and Gut Microbiota Interaction: Are There Any Sex/Gender Influences?

Accumulating evidence indicates that regular consumption of extra virgin olive oil (EVOO), the main source of fat in the Mediterranean diet, is associated with beneficial health effects and a reduced risk of developing chronic degenerative disorders. The beneficial effects of EVOO can be attributed to its unique composition in monounsaturated fats and phenolic compounds that provide important antioxidant, anti-inflammatory, and immune-modulating activities. On the other hand, it is well known that the gut microbiota has several important roles in normal human physiology, and its composition can be influenced by a multitude of environmental and lifestyle factors, among which dietary components play a relevant role. In the last few years, the two-way interaction between polyphenols, including those in EVOO, and the gut microbiota, i.e., the modulation of the microbiota by polyphenols and that of polyphenol metabolism and bioavailability by the microbiota, has attracted growing attention, being potentially relevant to explain the final effects of polyphenols, as well as of the microbiota profile. Furthermore, sex and gender can affect dietary habits, polyphenol intake, and nutrient metabolism. Lastly, it has been recently suggested that differences in gut microbiota composition could be involved in the unequal incidence of metabolic diseases observed between women and men, due to sex-dependent effects on shaping gut microbiota profiles according to diet. This review summarizes the most recent studies on the relationship between EVOO polyphenols and the gut microbiota, taking into account possible influences of sex and gender in modulating such an interaction.

Abstract P067: Sex-Specific Protection Of Fermentable Dietary Fiber On Salt-Sensitive Hypertension And Renal Function

Our recent data show that female Dahl Salt-Sensitive (SS) rats are significantly protected from salt-induced hypertension and renal injury and have stark differences in gut microbiota composition compared to males. Gut-derived metabolites are gaining recognition as mechanistic links between the microbiota and disease. One such metabolite is propionate, a protective short-chain fatty acid byproduct of bacterial fiber fermentation. Metabolomics revealed a specific elevation in serum propionate in female versus male SS rats after high salt (HS) (40.3±3.8 vs 24.4±4.2 μM, female vs male, p<0.02, n=6), and propionate administration to male SS rats blunts salt-induced elevations in mean arterial pressure and albuminuria (MAP, HS21: 160.5±6.6 vs 141.8±3.5 mmHg, p<0.05; albuminuria: 437.8±108.6 vs 263.6±50.33 mg/day, p<0.19, control vs propionate, 200mM p.o.; n=3-4). Therefore, the current study hypothesized that substitution of non-fermentable fiber cellulose with the fermentable fiber inulin (AIN-76A, Dyets Inc), a known precursor of short-chain fatty acids, would attenuate salt-sensitivity in males. Males and females were placed on the 0.4% NaCl (LS) inulin diet for one week prior to the switch to a 4.0% NaCl (HS) inulin diet for 4 weeks (inulin-M: n=7, inulin-F: n=6). Controls were maintained on either LS or HS diets containing cellulose (control-M: n=9, control-F: n=11). While there were no significant MAP differences observed in males, the inulin diet significantly reduced albuminuria (370.8±32.4 vs 174.4±30.0 mg/day on HS28, control-M vs inulin-M, p<0.001), reduced CD45+ renal leukocytes (35% reduction, p<0.03), reduced BUN (21.6±2.0 vs 15.4±0.5 mg/dL, p<0.05), and increased creatinine clearance (0.44±0.02 vs 0.55±0.02 ml/min/g KW, p<0.001). In females, inulin significantly lowered MAP (170.2±6.2 vs 154.6±4.5 mmHg on HS28, control-F vs inulin-F, p<0.01), albuminuria (180.3±27.4 vs 68.0±8.3, p<0.001), BUN (21.7±1.2 vs 17.9±0.6 mg/dL, p<0.05), and improved creatinine clearance (0.53±0.04 vs 0.71±0.05 ml/min/g KW, p<0.05). In summary, substitution of the fermentable fiber inulin reduced blood pressure only in females, but all other measures indicate improved renal injury, function, and inflammation in both sexes.

Differences in Gut Microbiota Composition and Predicted Metabolic Functions: a Pilot Study of Adolescents with Normal Weight and Obesity.

Understanding the principles underlying the stability and sustainability of the gut microbiome of adolescents with normal weight and obesity will make it possible to implement a personalized approach to the correction of metabolic disorders. The article presents the results of a pilot study of the diversity and metabolic potential of the gut microbiome in adolescents with normal body weight and obesity. Biological material was studied using metagenomic sequencing of the V3-V4 variable regions of the 16S rRNA gene. In all adolescents with normal weight, similar degree of the phylogenetic relationship between the bacterial taxa of the community was demonstrated. In contrast, obese adolescents were characterized by the presence of phylogenetically distinct taxa in the gut microbiota. However, even with differences in taxonomic composition, the gut microbial community can compensate for the absence of certain taxonomic groups by implementing the necessary metabolic functions using other phylogenetically close taxa.

Development of the gut microbiota in healthy twins during the first 2 years of life and associations with body mass index z-score: Results from the Wuhan twin birth cohort study.

The gut microbiota undergoes rapid and vital changes to microbial community structure and the microbial-immune crosstalk during the first 3 years of life, which is thought to be involved in the pathobiology of later-life disease. Compared to single-born children, little is known about the gut microbiota of twins in early childhood. Based on the Wuhan Twin Birth Cohort study, 344 stool samples from 204 twin families were analyzed to investigate the difference in gut microbiota composition at 6, 12, and 24 months of age. Furthermore, this study evaluated the association between gut microbiota development curves and body mass index z-score (BMI_Z) curves at 6, 12, and 24 months of age. The predominant microbiota phyla identified in twins were Proteobacteria, Actinobacteriota, Firmicutes, Bacteroidota, and Verrucomicrobiota. The richness and diversity of gut microbiota increased from 6 to 24 months old (alpha diversity with p < 0.05). Beta diversity revealed 61 gut microbiota genera that were significantly different in relative abundance among the three age groups. Among the 61 gut microbiota genera, 30 distinct trajectory curves (DTCs) were generated by group-based trajectory models after log2 transformation of their relative abundance. Subsequently, Spearman correlation analysis revealed that only five gut microbiota DTC were correlated with the BMI_Z DTC. Therefore, we further examined the association between the five gut microbiota genera DTC and BMI_Z DTC using generalized estimation equation models. The results revealed a significant association between the DTC groups of Parabacteroides and that of BMI_Z (coefficient = 0.75, p = 0.04). The results of this study validated the hypothesis that the richness and diversity of gut microbiota developed with age in twins. Moreover, participants with a higher DTC of log2-transformed Parabacteroides had a higher BMI_Z DTC during the first 2 years of life. Further studies are needed to confirm the association between Parabacteroides and BMI_Z in other populations.

Gut microbiota individuality is contingent on temporal scale and age in wild meerkats.

Inter-individual differences in gut microbiota composition are hypothesized to generate variation in host fitness-a premise for the evolution of host-gut microbe symbioses. However, recent evidence suggests that gut microbial communities are highly dynamic, challenging the notion that individuals harbour unique gut microbial phenotypes. Leveraging a long-term dataset of wild meerkats, we reconcile these concepts by demonstrating that the relative importance of identity for shaping gut microbiota phenotypes depends on the temporal scale. Across meerkat lifespan, year-to-year variation overshadowed the effects of identity and social group in predicting gut microbiota composition, with identity explaining on average less than 2% of variation. However, identity was the strongest predictor of microbial phenotypes over short sampling intervals (less than two months), predicting on average 20% of variation. The effect of identity was also dependent on meerkat age, with the gut microbiota becoming more individualized and stable as meerkats aged. Nevertheless, while the predictive power of identity was negligible after two months, gut microbiota composition remained weakly individualized compared to that of other meerkats for up to 1 year. These findings illuminate the degree to which individualized gut microbial signatures can be expected, with important implications for the time frames over which gut microbial phenotypes may mediate host physiology, behaviour and fitness in natural populations.

Gut Microbiota Composition in Prediabetes and Newly Diagnosed Type 2 Diabetes: A Systematic Review of Observational Studies.

Evidence of gut microbiota involvement in regulating glucose metabolism and type 2 diabetes mellitus (T2DM) progression is accumulating. The understanding of microbial dysbiosis and specific alterations of gut microbiota composition that occur during the early stages of glucose intolerance, unperturbed by anti-diabetic medications, is especially essential. Hence, this systematic review was conducted to summarise the existing evidence related to microbiota composition and diversity in individuals with prediabetes (preDM) and individuals newly diagnosed with T2DM (newDM) in comparison to individuals with normal glucose tolerance (nonDM). A systematic search of the PubMed, MEDLINE and CINAHL databases were conducted from inception to February 2021 supplemented with manual searches of the list of references. The primary keywords of “type 2 diabetes”, “prediabetes”, “newly-diagnosed” and “gut microbiota” were used. Observational studies that conducted analysis of the gut microbiota of respondents with preDM and newDM were included. The quality of the studies was assessed using the modified Newcastle-Ottawa scale by independent reviewers. A total of 18 studies (5,489 participants) were included. Low gut microbial diversity was generally observed in preDM and newDM when compared to nonDM. Differences in gut microbiota composition between the disease groups and nonDM were inconsistent across the included studies. Four out of the 18 studies found increased abundance of phylum Firmicutes along with decreased abundance of Bacteroidetes in newDM. At the genus/species levels, decreased abundance of Faecalibacterium prausnitzii, Roseburia, Dialister, Flavonifractor, Alistipes, Haemophilus and Akkermansia muciniphila and increased abundance of Lactobacillus, Streptococcus, Escherichia, Veillonella and Collinsella were observed in the disease groups in at least two studies. Lactobacillus was also found to positively correlate with fasting plasma glucose (FPG), HbA1c and/or homeostatic assessment of insulin resistance (HOMA-IR) in four studies. This renders a need for further investigations on the species/strain-specific role of endogenously present Lactobacillus in glucose regulation mechanism and T2DM disease progression. Differences in dietary intake caused significant variation in specific bacterial abundances. More studies are needed to establish more consistent associations, between clinical biomarkers or dietary intake and specific gut bacterial composition in prediabetes and early T2DM.

Variations in the fecal microbiota and their functions of Thoroughbred, Mongolian, and Hybrid horses.

The horse gut is colonized by a rich and complex microbial community that has important roles in horse physiology, metabolism, nutrition, and immune functions. Fewer across-breed variations in horse gut microbial diversity have been illustrated. In this article, the gut microbiota of Thoroughbred, Mongolian, and Hybrid horses [first filial generation (F1) of Mongolian (maternal) and Thoroughbred (paternal)] were studied by second-generation high-throughput sequencing technology. Differences in gut microbiota composition and function between breeds were determined using diversity and functional prediction analysis. The alpha diversity analysis showed that Thoroughbred horses had a more abundant and diverse gut microbiota, while the diversity of gut microbiota in Hybrid horses was intermediate between Thoroughbred and Mongolian horses. Subsequent cluster analysis showed that Hybrid horses have a microbiota composition more similar to Mongolian horses. LEfSe analysis revealed that the bacterial biomarkers for Thoroughbred horses at the family level were Prevotellaceae, Rikenellaceae, Fibrobacteraceae, p_251_o5, Lactobacillaceae, and uncultured_bacterium_o_WCHB1_41; the bacterial biomarker for Mongolian horses was Planococcaceae; and the bacterial biomarkers for Hybrid horses were Moraxellaceae, Enterobacteriaceae, and Ruminococcaceae. The functional prediction results indicated that the metabolic pathways differ significantly between the breeds. Regarding metabolism, the Hybrid horses had the lowest proportion of the carbohydrate metabolic pathways, while the energy metabolic pathway had the highest proportion. The abundance ratios of the remaining eight metabolic pathways in Hybrid horses were between Thoroughbred and Mongolian horses. In conclusion, the results of this study showed an association between horse breeds and gut microbiota.

Crosstalk Between Gut Microflora and Vitamin D Receptor SNPs Are Associated with the Risk of Amnestic Mild Cognitive Impairment in a Chinese Elderly Population.

The interactions between environmental factors and genetic variants have been implicated in the pathogenesis of Alzheimer's disease (AD). The altered gut microbiota (GM) and vitamin D deficiency are closely associated with the higher risk of AD. This study was performed to evaluate whether the crosstalk between GM and single nucleotide polymorphisms (SNPs) of vitamin D receptor (VDR) or vitamin D binding protein (VDBP) have a link with the risk of amnestic mild cognitive impairment (aMCI) in the Chinese elderly population. A total of 171 aMCI patients and 261 cognitive normal controls (NC) were enrolled in this study. Six tag SNPs of VDR and VDBP were genotyped by PCR-RFLP. The serum levels of vitamin D, Aβ1-42, and p-tau (181P) were determined by using of ELISA kits. The alterations in the GM were analyzed by full-length 16S ribosomal RNA (rRNA) gene sequencing. The frequencies of AG genotype and A allele of VDR rs1544410 in aMCI group were significantly higher than that in NC group (genotype: p = 0.002, allele: p = 0.003). Patients with aMCI showed an abnormal GM composition compared with NC group. Interestingly, significant differences in GM composition were found between aMCI and NC group among individuals with AG genotype, as well as between individuals with AG and GG genotype of VDR rs1544410 among patients with aMCI. These results implicated that the crosstalk between gut microflora and vitamin D receptor variants are associated with the risk of aMCI in Chinese elderly population.

Human gut microbiota composition and its predicted functional properties in people with western and healthy dietary patterns

PurposeSome dietary habits cluster together, and for this reason it is advised to study the impact of entire dietary patterns on human health, rather than that of individual dietary habits. The main objective of this study was to evaluate differences in gut microbiota composition and their predicted functional properties between people with a healthy (HDP) and western (WDP) dietary pattern.MethodsA cross-sectional, observational study was carried out on 200 participants enrolled 2017–2018 in Poznań, Poland, equally distributed into HDP and WDP groups. Diet was estimated using 3-day food records and information on stool transit times was collected. Fecal microbiota composition was assessed by 16S rRNA gene sequencing and its functional properties were predicted by the PICRUSt2 workflow.ResultsThe α-diversity did not differ between people with WDP and HDP, but β-diversity was associated with dietary pattern. People with HDP had higher relative abundances (RA) of Firmicutes and Faecalibacterium and lower RA of Bacteroidota and Escherichia–Shigella than participants with WDP. Only a small proportion of the variance in microbiota composition (1.8%) and its functional properties (2.9%) could be explained by dietary intake (legumes, simple sugars and their sources, like fruit, soft drinks) and stool transit characteristics.ConclusionGut microbiota composition and predicted metabolic potential is shaped by overall diet quality as well as the frequency of defecation; however, the cumulative effect of these explain only a relatively low proportion of variance.

Dysbiosis in Children With Neurological Impairment and Long-Term Enteral Nutrition.

Severe neurological impairment (NI) is often accompanied by the need for artificial nutritional support, normally provided enterally (enteral nutrition [EN]) to ensure growth, counteract morbidity and mortality, and improve quality of life. On the other hand, long-term EN (LTEN) may contribute to the establishment, or exacerbation, of gastrointestinal disorders that may lead to malnutrition, which in turn is associated with alterations in gut microbiota (GM) composition and functional capacities. To the best of our knowledge, we investigated, for the first time in this study, the consequences of LTEN in a pediatric population in this pathological context. Using amplicon sequencing, we compared the fecal microbiota of a pediatric population suffering from severe NI and under LTEN to that of sex- and age-matched controls. The two groups presented evident differences in GM composition and a consistent differential clustering. In general, the taxonomic picture in NI children under LTEN seemed to mirror a profound dysbiotic condition, in which anti-inflammatory taxa appear severely depleted (among others, the Clostridiales families of Lachnospiraceae and Ruminococcaceae, and, within the latter, Faecalibacterium spp. and Gemmiger spp.), while known pathobionts (Gammaproteobacteria and Klebsiella) or emerging pathogens (e.g., Synergistales, Cloacibacillus, and Fusobacterium) were significantly enriched. Our data suggest that LTEN has a significant impact on the GM taxonomic composition in NI children. Even if other factors are probably at work, such as the bidirectional interaction between gastrointestinal impairment/immaturity and the central nervous system (CNS), the assumption of drugs, and physical inactivity, these data define possible routes and targets to try to alleviate this dysbiosis, with a view to better management of these patients and an improvement in their quality of life.

The Component and Functional Pathways of Gut Microbiota Are Altered in Populations with Poor Sleep Quality - A Preliminary Report.

With the development of genome sequencing, many researchers have investigated the mechanism by which the intestinal microbiota influences sleep across the brain-gut axis. However, the relationship between gut microbiota and sleep disorder remains unclear. Thus, we studied the difference in gut microbiota composition between poor sleep quality- and normal populations, which helps set the ground for future research. The recruited college students provided baseline information and stool samples and completed the Pittsburgh Sleep Quality Index (PSQI). We compared the two groups’ gut microbiota composition and functional differentiation by using the 16S rRNA gene sequencing analysis. The main bacterial difference and the most critical effect were mainly concentrated within Tenericutes and Elusimicrobia. Compared with the healthy control group, some functions of the gut microbiota were impaired in the poor sleep quality group, such as butanoate metabolism and propanoate metabolism. Bacterial taxa with significant differences raised the possibility for future diagnosis and treatment of sleep problems.

Intestinal Microbial Composition of Children in a Randomized Controlled Trial of Probiotics to Treat Acute Gastroenteritis.

Compositional analysis of the intestinal microbiome in pre-schoolers is understudied. Effects of probiotics on the gut microbiota were evaluated in children under 4-years-old presenting to an emergency department with acute gastroenteritis. Included were 70 study participants (n=32 placebo, n=38 probiotics) with stool specimens at baseline (day 0), day 5, and after a washout period (day 28). Microbiota composition and deduced functions were profiled using 16S ribosomal RNA sequencing and predictive metagenomics, respectively. Probiotics were detected at day 5 of administration but otherwise had no discernable effects, whereas detection of bacterial infection (P<0.001) and participant age (P<0.001) had the largest effects on microbiota composition, microbial diversity, and deduced bacterial functions. Participants under 1 year had lower bacterial diversity than older aged pre-schoolers; compositional changes of individual bacterial taxa were associated with maturation of the gut microbiota. Advances in age were associated with differences in gut microbiota composition and deduced microbial functions, which have the potential to impact health later in life.Clinical Trial Registration www.ClinicalTrials.gov, identifier: NCT01853124.

Associations Between Physical Activity and Gut Microbiota Composition in Adults With Overweight and Obesity

ObjectivesTo assess whether physical activity (PA) volume and intensities are associated with differences in the gut microbiota composition or short-chain fatty acid (SCFA) profile of adults with overweight or obesity.MethodsPA data and fecal samples collected pre-intervention for the Persea americana for Total Health (PATH) study were used to assess cross-sectional correlations between PA and gut microbiota composition. Adults between 25 and 45 years of age with a body mass index (BMI) ≥ 25 kg/m2 were enrolled. Gut microbiota composition was assessed with 16S rRNA gene sequencing. PA was measured with a hip-worn ActiGraph wGT3X-BT accelerometer. PA volume was defined as total activity counts and light-to-vigorous PA per day. Sedentary time was defined as < 100 counts per minute (CPM; sedentary). PA intensities were defined as: ≥100 < 2020 (light), ≥2020 < 5999 (moderate), and ≥ 5999 (vigorous) CPM, and expressed in min/day. Correlations between PA and gut microbiota composition were assessed using linear mixed models. K-means clustering was used to categorize participants based on PA and determine whether gut microbiota composition was significantly different between clusters using Analysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC) and DESeq2.ResultsData for both PA and gut microbiota composition were available for 124 participants. PA intensity was not correlated with differences in gut microbiota composition. PA volume and sedentary time were correlated with differences in gut microbiota composition and SCFA concentrations. Clustering of individuals based on PA resulted in two clusters. Cluster 2 (n = 33) displayed lower PA than Cluster 1 (n = 91). Clusters showed no significant differences in alpha or beta diversity, but Cluster 2 had higher levels of Akkermansia and displayed significant differences in SCFA profile.ConclusionsThis analysis suggests that PA volume is associated with the gut microbiota composition and SCFA profile of adults with overweight and obesity. Future studies should investigate these associations in a broader population of adults with a wider range of BMI and PA to better understand how PA may influence the human gut microbiota and health.Funding SourcesHass Avocado Board and the USDA National Institute of Food and Agriculture.

Gut Microbiota and Associated Mucosal Immune Response in Eosinophilic Granulomatosis with Polyangiitis (EGPA).

Eosinophilic granulomatosis with polyangiitis (EGPA) is an anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. A genome-wide association study showed a correlation between ANCA-negative EGPA and variants of genes encoding proteins with intestinal barrier functions, suggesting that modifications of the mucosal layer and consequent gut dysbiosis might be involved in EGPA pathogenesis. Here, we characterized the gut microbiota (GM) composition and the intestinal immune response in a cohort of EGPA patients. Faeces from 29 patients and 9 unrelated healthy cohabitants were collected, and GM and derived metabolites’ composition were compared. Seven intestinal biopsies from EGPA patients with gastrointestinal manifestations were analysed to assess the T-cell distribution and its correlation with GM and EGPA clinical and laboratory features. No significant differences in GM composition, nor in the total amount of faecal metabolites, emerged between patients and controls. Nevertheless, differences in bacterial taxa abundances and compositional GM-derived metabolites profile were observed. Notably, an enrichment of potential pathobionts (Enterobacteriacee and Streptococcaceae) was found in EGPA, particularly in patients with active disease, while lower levels were found in patients on immunosuppression, compared with non-immunosuppressed ones. Significantly lower amounts of hexanoic acid were found in patients, compared to controls. The analysis of the immune response in the gut mucosa revealed a high frequency of IFN-γ/IL-17-producing T lymphocytes, and a positive correlation between EGPA disease activity and intestinal T-cell levels. Our data suggest that an enrichment in potential intestinal pathobionts might drive an imbalanced inflammatory response in EGPA.

Gut Microbiome Suffers from Hematopoietic Stem Cell Transplantation in Childhood and Its Characteristics Are Positively Associated with Intra-Hospital Physical Exercise.

Simple SummaryGut microbiome research has rapidly advanced with good perspectives for the diagnostics and/or therapy of a plethora of diseases, including metabolic and neurodegenerative diseases and various types of cancer. In this study, we examined the composition of the fecal microbiota of eligible children with acute lymphoblastic leukemia (ALL) after hematopoietic stem cell transplantation (HSCT). We found a negative effect of HSCT treatment on microbiome bacterial diversity and richness with microbial monodominance by pathogenic bacteria in pediatric ALL patients after 3 months. The changes in the gut microbiota were associated with systemic inflammation on day + 28. However, promisingly, we have observed an association between bacterial diversity and physical exercise during HSCT treatment. Our findings provide additional support for the importance of investigating the gut microbiome in children with cancer.Gut microbiome impairment is a serious side effect of cancer treatment. The aim of this study was to identify the effects of hematopoietic stem cell transplantation (HSCT) treatment on gut microbiota composition in children with acute lymphoblastic leukemia (ALL). Fecal microbiotas were categorized using specific primers targeting the V1–V3 region of 16S rDNA in eligible pediatric ALL patients after HSCT (n = 16) and in healthy controls (Ctrl, n = 13). An intra-hospital exercise program was also organized for child patients during HSCT treatment. Significant differences in gut microbiota composition were observed between ALL HSCT and Ctrl with further negative effects. Plasma C-reactive protein correlated positively with the pathogenic bacteria Enterococcus spp. and negatively with beneficial bacteria Butyriccocus spp. or Akkermansia spp., respectively (rs = 0.511, p = 0.05; rs = −0.541, p = 0.04; rs = −0.738, p = 0.02). Bacterial alpha diversity correlated with the exercise training characteristics. Therefore, specific changes in the microbiota of children were associated with systemic inflammation or the ability to exercise physically during HSCT treatment.