Gut Bacterial Abundance Research Articles

The potential mediating role of the gut microbiome and metabolites in the association between PFAS and kidney function in young adults: A proof-of-concept study.

Chronic kidney disease (CKD) affects over 10% of the global population and can lead to kidney failure and death. Exposure to per- and polyfluoroalkyl substances (PFAS) is associated with increased risk of CKD, yet studies examining the mechanisms linking PFAS and kidney function are lacking. In this exploratory study, we examined longitudinal associations of PFAS exposure with kidney function, and tested if associations were mediated by altered gut bacterial taxa or plasma metabolites using a multi-omics mediation analysis. Seventy-eight young adults from the Children's Health Study were included in this longitudinal cohort study. At baseline, seven plasma PFAS and untargeted plasma metabolomics were measured using liquid chromatography/mass-spectrometry. Baseline gut bacterial abundance was characterized using 16S rRNA sequencing and examined at the genus level. At follow-up, serum creatinine and cystatin-C concentrations were quantified to estimate glomerular filtration rate (eGFR). High-dimensional multi-omics analyses were conducted to assess the association between baseline PFAS exposure with follow-up eGFR, mediated by gut microbiome and circulating metabolite levels. PFAS burden score, a variable developed to estimate exposure to chemical mixtures, was associated with kidney function. Each standard deviation increase in baseline PFAS burden score was associated with a 2.4% lower eGFR at follow-up (95% CI:[0.1%,4.8%]). Following high-dimensional mediation analyses with the microbiome and circulating metabolites, a joint component (characterized by reduced Lachnospiraceae and 17b-estradiol and increased succinate, retinoate and dodecanoic acid) and a metabolite component (characterized by increased hypotaurine and decreased D-pinitol and ureidopropionate) mediated 38% and 50% of the effect between PFAS burden score and eGFR, respectively. Our proof-of-concept analysis provides the first evidence that reduced short-chain fatty acid-producing bacteria and anti-inflammatory metabolites may link PFAS exposure with impaired kidney function. This study raises the possibility of future targeted interventions that can alter gut microbiome or circulating metabolite profiles to prevent PFAS induced kidney damage.

Fishmeal substitution by zooplankton or Daphnia magna biomass meals in the diet of Nile tilapia: Effectson growth, gut histological changes, bacterial abundanceand stress tolerance.

Fishmeal substitution with sustainable feed sources is highly essential towards sustainable production. This study aimed to investigate the effects of substituting fishmeal (FM) with Daphnia magna biomass meal (DBM) or zooplankton biomass meal (ZBM) on growth performance, liverand intestinal histology, gut bacterial abundanceand stress tolerance of Nile tilapia, Oreochromis niloticus, fry. Nile tilapia fry (0.23 ± 0.04 g) were randomly assigned to five groups of three replicates. The control diet comprised 300 g/kg FM, and the FM was substituted with DBM or ZBM at levels of 25% and 50% (DBM-25, DBM-50, ZBM-25and ZBM-50respectively) in the other experimental diets. The experiment lasted 56 days in 1.5 m3 concrete tanks. The results revealed that weight gain andfeed conversion ratio(FCR) significantly (p ≤ 0.035 and 0.025respectively) improved with a polynomial response with a peak at 25% ZBM and a linear increase with DBM up to 50% of FM. Histometric indices of the distal intestine showed improvements (p ≤ 0.001) in villus height, villus width, crypt depthand muscle thickness of fish fed DBM or ZBM compared to the control. In the meantime, there were no histological abnormalities in the liver sections. The replacement of FM with DBM or ZBM could modulated gut bacterial abundance, including total bacterial count, Escherichia coli, Bacillus subtilis, and Lactobacillus sp. The fish-fed DBM or ZBM-containing diets had higher (p ≤ 0.05) tolerances to salinity stress than the control group. In conclusion, DBM or ZBM could replace FM up to 50% and 25%, respectivelywith improved fish growth performance, FCR, gut histologyand tolerance to salinity stress.

Focus On Prebiotic and Probiotic Preventive and Therapeutic Diet Approaches to Restore Gut Homeostasis in Rodent Models of Autism

Although variable diet approaches shaped the gut bacterial abundance differently, they are considered the core factors in modulating gut microbiota throughdifferent mechanisms. Our aim in this study is to focus on the dietary candidates that could maintain a healthy gut microbiota by promoting commensal bacteria and reducingor inhibiting pathogens. In the current study, our objective is to demonstrate that a novel combined dietary approach of pre-and probiotic mixtures could be more effectivein inducing significant improvements in gut bacterial composition as a target to treat ASD. Luteolin complex veggie capsules (Swanson, USA), artichoke extract, as well asyogurt and Lactobacillus rhamnosus veggie capsules (5 billion CFU) (Swanson, USA), recently known as Lacticaseibacillus rhamnosus were selected as prebiotics and probioticsrespectively and were screened for their protective and therapeutic effects on the gut microbiota. They were all administered orally over 5 weeks to propionic acid PPAtreatedrats as rodent models of Autism (groups 4-10). Their results were compared to the control animal group undertaking a standard diet (group 1) and to post and pre-PPA-treated groups (groups 2 and 3). Lactobacillus and Bifidobacterium were noted as the most dominant, non-fluctuating strains in response to all diet intakes, and theynegatively influenced the presence of Proteobacteria (Enterobacteriaceae), which decreased in almost all treated groups during weeks 2 and 3, and 4.Interestingly, Clostridiumsp. was observed to be high in number at week 1, mainly in the control group (1) and pre and post-PPA groups (2 and 3), but were inhibited in all treated groups over theextended treatment period. Bacteroidetes were positively increased with the high presence of Lactobacillus and Bifidobacterium spp. Levels throughout the experiment in almostall animal groups. Thus, both prebiotics and probiotics study designed candidates (Luteolin complex capsules, artichoke extract, yogurt, and L. rhamnosus capsules) inhibitedClostridium sp., promoted commensal bacteria, specifically Lactobacillus and Bifidobacterium spp., restored the normal gut bacterial niches and therefore could be consideredas potential promising dietary approaches for maintaining healthy physical and microbial gut strategies.

Subdiaphragmatic vagal nerve stimulation attenuates the development of hypertension and alters nucleus of the solitary tract transcriptional networks in the spontaneously hypertensive rat.

Augmented vagal signaling may be therapeutic in hypertension. Most studies to date have used stimulation of the cervical vagal branches. Here, we investigated the effects of chronic intermittent electric stimulation of the ventral subdiaphragmatic vagal nerve branch (sdVNS) on long-term blood pressure, immune markers, and gut microbiota in the spontaneously hypertensive rat (SHR), a rodent model of hypertension characterized by vagal dysfunction, gut dysbiosis, and low-grade inflammation. We evaluated the effects of sdVNS on transcriptional networks in the nucleus of the solitary tract (NTS), a major cardioregulatory brain region with direct gut vagal projections. Male juvenile SHRs were implanted with radiotelemetry transmitters and vagal nerve cuffs for chronic intermittent electric sdVNS, applied three times per day for 7 consecutive weeks followed by 1 wk of no stimulation. Blood pressure was measured once a week using telemetry in the sdVNS group as well as age-matched sham-stimulated SHR controls. At the endpoint, colonic and circulating inflammatory markers, corticosterone, and circulating catecholamines were investigated. Bacterial 16 s sequencing measured gut bacterial abundance and composition. RNA sequencing evaluated the effects of sdVNS on transcriptional networks in the NTS. SHRs that received sdVNS exhibited attenuated development of hypertension compared with sham animals. No changes in peripheral inflammatory markers, corticosterone, or catecholamines and no major differences in gut bacterial diversity and composition were observed following sdVNS, apart from decreased abundance of Defluviitaleaceale bacterium detected in sdVNS SHRs compared with sham animals. RNA sequencing revealed significant sdVNS-dependent modulation of select NTS transcriptional networks, including catecholaminergic and corticosteroid networks.NEW & NOTEWORTHY We show that stimulation of the ventral subdiaphragmatic vagal nerve branch may be a promising potential approach to treating hypertension. The data are especially encouraging given that rodents received only 30 min per day of intermittent stimulation therapy and in view of the potential of long-term blood pressure effects that are not stimulus-locked.

Capsazepine-Induced Altered Colonic Mucosal Health Limits Isomalto-oligosaccharide Action in High-Fat Diet-Fed C57BL/6J Mice.

The present study sought to understand the effects of a combination of altered colonic mucosal health (intrarectal capsazepine administration) and high-fat diet (HFD) administration in mice. Furthermore, we also studied whether this combination prevents protective actions of dietary prebiotic, isomaltooligosaccharides. We studied the alterations in intestinal permeability, histological and transcriptional changes, short-chain fatty acid (SCFA) concentrations, and gut microbial abundance. Capsazepine (CPZ) was administered rectally twice a day along with HFD feeding. Following confirmation of CPZ action (loss of TRPA1 and TRPV1-associated nocifensive behavior), the intrarectal dose of CPZ was reduced to once in 2 days up to 8 weeks. Simultaneous intrarectal administration of CPZ exacerbated the HFD (8 weeks feeding)-induced damage to mucosal lining, intestinal permeability, tight junction protein expression, SCFA levels, and gut bacterial abundances. This higher degree of mucosal damage and pathological alteration in colonic mucosa prevented the previously reported protective actions of isomaltooligosaccharides as a prebiotic in HFD-fed mice. Overall, we present evidence that colonic precondition (gut permeability and mucosal lining) is an important factor in determination of HFD-induced changes in the colon, and success of diet-associated interventions (dietary fibers, pre/probiotics, etc.) is dependent on it.

Feeding on soybean crops changed gut bacteria diversity of the southern green stinkbug (Nezara viridula) and reduced negative effects of some associated bacteria.

The southern green stinkbug (Nezara viridula) is a mayor pest of soybean. However, the mechanism underlying stinkbug resistance to soybean defenses is yet ignored. Although gut bacteria could play an essential role in tolerating plant defenses, most studies testing questions related to insect-plant-bacteria interactions have been performed in laboratory condition. Here we performed experiments in laboratory and field conditions with N. viridula and its gut bacteria, studying gut lipid peroxidaxion levels and cysteine activity in infected and unifected nymphs, testing the hypothesis that feeding on field-grown soybean decreases bacterial abundance in stinkbugs. Gut bacterial abundance and infection ratio were higher in N. viridula adults reared in laboratory than in those collected from soybean crops, suggesting that stinkbugs in field conditions may modulate gut bacterial colonization. Manipulating gut microbiota by infecting stinkbugs with Yokenella sp. showed that these bacteria abundance decreased in field conditions, and negatively affected stinkbugs performance and were more aggressive in laboratory rearing than in field conditions. Infected nymphs that fed on soybean pods had lower mortality, higher mass and shorter development period than those reared in the laboratory, and suggested that field conditions helped nymphs to recover from Yokenella sp. infection, despite of increased lipid peroxidation and decreased cysteine proteases activity in nymphs' guts. Our results demonstrated that feeding on field-grown soybean reduced bacterial abundance and infection in guts of N. viridula and highlighted the importance to test functional activities or pathogenicity of microbes under realistic field conditions prior to establish conclusions on three trophic interactions. © 2022 Society of Chemical Industry.

Growth Performance, Immune-Related and Antioxidant Genes Expression, and Gut Bacterial Abundance of Pacific White Leg Shrimp, Litopenaeus vannamei, Dietary Supplemented With Natural Astaxanthin.

The current study examines the effect of dietary supplementation of ethanolic extract of Arthrospira platensis NIOF17/003, which is mainly natural astaxanthins (97.50%), on the growth performance, feed utilization, bacterial abundance, and immune-related and antioxidant gene expressions of the Pacific white leg shrimp, Litopenaeus vannamei. A total of 360 healthy L. vannamei postlarvae (0.19 ± 0.003 g) were divided into four groups (0, 2, 4, and 6 g natural astaxanthins/kg diet) each in three replicates, at an initial density of 30 PLs per tank (40 L capacity). The shrimp were fed the tested diets three times a day at a rate of 10% of their total body weight for 90 days. Diets supplemented with different astaxanthin levels significantly improved shrimp growth performance and feed conversion ratio compared to the control diet. No significant differences were observed in survival rates among all experimental groups. The immune-related genes (prophenoloxidase, lysozyme, beta-glucan binding protein, transglutaminase, and crustin) mRNA levels were significantly upregulated in groups fed with different concentrations of the natural astaxanthins in a dose-dependent manner. The prophenoloxidase gene is the highest immune-upregulated gene (14.71-fold change) in response to astaxanthin supplementation. The superoxide dismutase mRNA level was significantly increased with increasing dietary astaxanthin supplementation. In addition, increasing astaxanthin supplementation levels significantly reduced the count of heterotrophic bacteria and Vibrio spp. in the culture water and shrimp intestine. Overall, the current results concluded that diet supplementation with natural astaxanthin, extracted from Arthrospira platensis, enhanced the growth performance, immune response, and antioxidant status of L. vannamei.

Simulated Climate Warming Influenced Colony Microclimatic Conditions and Gut Bacterial Abundance of Honeybee Subspecies Apis mellifera ligustica and A. mellifera sinisxinyuan

Abstract Ectothermic organisms including insects are highly vulnerable to climate warming which not only influences their biology, ecology and physiology but also affects their symbiotic gut microbiota. This study determined the impact of ambient (control) and simulated warmer (heating) climatic conditions on the microclimate of brood nest and gut bacterial abundance of two Apis mellifera subspecies i.e. A. mellifera ligustica and A. mellifera sinisxinyuan. For both subspecies, brood nest temperature and relative humidity under the heating treatment were significantly different (p≤0.001) than those under the control treatment. Quantitative PCR data revealed that the abundance of gut bacteria (16S rRNA gene copy numbers) of A. mellifera ligustica and A. mellifera sinisxinyuan larvae was significantly higher (P≤0.05), 1.73 and 5.32 fold higher respectively, during the heating treatment than those in control conditions. Although gut bacterial abundance of A. mellifera ligustica (1.67 × 107 copies g−1 fw) and A. mellifera sinisxinyuan (1.7 × 107 copies g−1 fw) larvae was similar during the control treatment, A. mellifera sinisxinyuan larvae exhibited three times greater gut bacterial abundance than A. mellifera ligustica during the heating treatment. Similarly, adult A. mellifera sinisxinyuan bees harboured significantly greater bacterial abundance during the heating treatment than control. These findings elucidate that climate warming may significantly affect the honeybee colony microclimate and their gut bacterial abundance. However, further studies are needed to better understand how gut microbial community may influence the learning, physiological and behavioural mechanisms of the host bees in a climate warming scenario.

Classic Hoarding Cages Increase Gut Bacterial Abundance and Reduce the Individual Immune Response of Honey Bee (Apis mellifera) Workers.

Laboratory experiments have advanced our understanding of honey bee (Apis mellifera) responses to environmental factors, but removal from the hive environment may also impact physiology. To examine whether the laboratory environment alters the honey bee gut bacterial community and immune responses, we compared bacterial community structure (based on amplicon sequence variant relative abundance), total bacterial abundance, and immune enzyme (phenoloxidase and glucose oxidase) activity of cohort honey bee workers kept under laboratory and hive conditions. Workers housed in the laboratory showed differences in the relative abundance of their core gut taxa, an increase in total gut bacterial abundance, and reduced phenoloxidase activity, compared to bees housed in hives.

High nitrogen in maize enriches gut microbiota conferring insecticide tolerance in lepidopteran pest Spodoptera litura

SummaryAbuse of chemical fertilizers and insecticides has created many environmental and human health hazards. We hypothesized that high nitrogen (N) in crops changes insect gut microbiota leading to enhanced insecticide tolerance. We investigated the effect of high N in maize on gut microbiota and insecticide tolerance of the polyphagous pest Spodoptera litura. Bioassays showed that high N applied in both maize plants and artificial diets significantly enhanced larval growth but reduced larval sensitivity to the insecticide methomyl. High N promoted the gut bacterial abundance in the genus Enterococcus. Inoculation with two strains (E. mundtii and E. casseliflavus) isolated from the larval guts increased larval tolerance to methomyl. Incorporation of antibiotics in a high-N diet increased the larval sensitivity to methomyl. These findings suggest that excessive application of N fertilizer to crops can increase insecticide tolerance of insect pests via changing gut microbiota, leading to increased use of insecticides worldwide.

Effect of Environmental Exposures on the Gut Microbiota from Early Infancy to Two Years of Age.

The gut microbiota undergoes rapid changes during infancy in response to early-life exposures. We have investigated how the infant gut bacterial community matures over time and how exposures such as human milk and antibiotic treatment alter gut microbiota development. We used the LonGP program to create predictive models to determine the contribution of exposures on infant gut bacterial abundances from one month to two years of age. These models indicate that infant antibiotic use, human milk intake, maternal pre-pregnancy BMI, and sample shipping time were associated with changes in gut microbiome composition. In most infants, Bacteroides, Lachnospiraceae unclassified, Faecalibacterium, Akkermansia, and Phascolarctobacterium abundance increased rapidly after 6 months, while Escherichia, Bifidobacterium, Veillonella, and Streptococcus decreased in abundance over time. Individual, time-varying, random effects explained most of the variation in the LonGP models. Multivariate association with linear models (MaAsLin) displayed partial agreement with LonGP in the predicted trajectories over time and in relation to significant factors such as human milk intake. Multiple factors influence the dynamic changes in bacterial composition of the infant gut. Within-individual differences dominate the temporal variations in the infant gut microbiome, suggesting individual temporal variability is an important feature to consider in studies with a longitudinal sampling design.

In vivo predation and modification of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) gut microbiome by the bacterial predator Bdellovibrio bacteriovorus.

The Mediterranean fruit fly (the medfly) causes major losses of agricultural fruits. Its microbiome is mainly composed of various Enterobacteriaceae that contribute to nutrient acquisition and are associated with the fly's development. Moreover, the performance of males produced by the sterile insect technique is improved by providing mass-reared insects with specific gut bacteria. Bdellovibrio and like organisms (BALOs) are obligate predators of Gram-negative bacteria that efficiently preys upon diverse Enterobacteriaceae, making it a potential disruptor of the fly's microbiome. We hypothesized that the fly's microbiome can be targeted to control the insect. Inoculation of B. bacteriovorus as free-swimming or encapsulated cells into gut extracts significantly reduced gut bacterial abundance, sustaining predator survival. Similar treatments applied to adult flies showed that the predators also survived in the gut environment. While addition of the predators did not affect total gut bacterial abundance and end-point fly mortality, a shift in the gut community structure, measured by high-throughput community sequencing was observed. The bacterial predator of bacteria B. bacteriovorus can prey and survive invivo in the medfly gut. This study establishes the potential of BALOs to affect the microbiome of insect hosts.

Microbiome analysis reveals the significant changes in gut microbiota of diarrheic Baer's Pochards (Aythya baeri)

Gut microbiota has been demonstrated to play multiple crucial roles in immunity, physiology, metabolism, and health maintenance. Diarrhea was closely related to the gut microbiota, but information regarding the alterations in gut microbial composition and structure in Baer's Pochard (Aythya baeri) with diarrhea remains scarce. Here, 16S rDNA amplicon sequencing was performed to investigate the gut microbial variability between diarrheic and healthy Baer's Pochard. Results indicated that the gut bacterial community of diarrheic Baer's Pochard showed a distinct decrease in alpha diversity, accompanied by evident changes in taxonomic compositions. Microbial taxonomic analysis revealed that Firmicutes, Proteobacteria and Bacteroidetes were the most dominant phyla in all the fecal samples regardless of health status. At the genus level, the differences in gut bacterial abundance between healthy and diarrheic populations were gradually observed. Specifically, the proportion of Elusimicrobia in the diarrheic Baer's Pochard was increased in comparison with healthy populations, while Acidobacteria, Rokubacteria, Cyanobacteria and Patescibacteria were dramatically decreased. Additionally, the relative proportion of 23 bacterial genera significantly decreased in diarrheic Baer's Pochard, whereas the relative percentage of 4 bacterial genera (Alkanindiges, Elusimicrobium, Spirosoma and Exiguobacterium) observably increased as compared to healthy populations. Taken together, the present study revealed that there were distinct differences in the gut microbial composition and diversity between the healthy and diarrheic Baer's Pochard. Remarkably, this is the first report on the differences in the gut microbiota of Baer's Pochard under different health states and may contribute to provide better insight into gut microbial composition and diversity of Baer's Pochard.

Alterations of the gut bacterial microbiota in rhesus macaques with SIV infection and on short- or long-term antiretroviral therapy

Gut dysbiosis and microbial translocation are associated with chronic systemic immune activation and inflammation in HIV-1 infection. However, the extent of restoration of gut microbiota in HIV-1 patients with short or long-term antiretroviral therapy (ART) is unclear. To understand the impact of ART on the gut microbiota, we used the rhesus macaque model of SIV infection to characterize and compare the gut microbial community upon SIV infection and during ART. We observed altered taxonomic compositions of gut microbiota communities upon SIV infection and at different time points of ART. SIV-infected animals showed decreased diversity of gut microbiome composition, while the ART group appeared to recover towards the diversity level of the healthy control. Animals undergoing ART for various lengths of time were observed to have differential gut bacterial abundance across different time points. In addition, increased blood lipopolysaccharide (LPS) levels during SIV infection were reduced to near normal upon ART, indicating that microbial translocation and immune activation can be improved during therapy. In conclusion, while short ART may be related to transient increase of certain pathogenic bacterial microbiome, ART may promote microbiome diversity compromised by SIV infection, improve the gut microbiota towards the healthy compositions and alleviate immune activation.

Investigation of the Diet-Gut-Muscle Axis in the Osteoporotic Fractures in Men Study.

To investigate the association between dietary fiber density (grams of fiber consumed per 100 kcal) with the gut-muscle axis in older adult men. Cross-sectional study. Osteoporotic Fractures in Men (MrOS) cohort participants at Visit 4 (2014-16). Older adult men (average age, 85y) from the MrOS study. Men who were in the highest tertiles for dietary fiber density and the percentage of whole body lean mass were defined as T3T3 (n=42), whereas men who were in the lowest and intermediate tertiles for these variables were defined as T1T1 (n=32), T1T3 (n=24), and T3T1 (n=13), respectively. Additionally, measures of physical function, including the short physical performance battery (SPPB) score and grip strength were higher in T3T3 when compared with T1T1. Gut bacterial abundance was quantified with use of 16S v4 rRNA sequencing, and the bacterial functional potential was derived from the 16S data with PICRUSt. Chao1, ACE, Shannon, Simpson, and Fisher indices were used as measures of α-diversity. Weighted and unweighted Unifrac, and Bray-Curtis were used as measures of β-diversity. Age, physical activity score, smoking, and number of medications-adjusted DESeq2 models were used to identify bacteria and functions that were different when comparing T3T3 with T1T1, but that were not also different when comparing T3T3 with T1T3 or T3T1. α-diversity was not different, but significant differences for β-diversity (unweighted UniFrac, Bray-Curtis) were identified when comparing T3T3 with T1T1. Known butyrate-producing bacteria, including Ruminococcus, Lachnospira, and Clostridia, and gene counts for butyrate production (KEGG IDs: K01034, K01035) were higher in T3T3, when compared with T1T1. These data suggest that a high-fiber diet may positively impact butyrate-producing genera and gene counts, which collectively may be involved in mechanisms related to the percentage of whole body lean mass and physical functioning in older adult men. Future studies aimed at testing the causative role of this hypothesis are of interest.

High Fat High Calories Diet (HFD) Increase Gut Susceptibility to Carcinogens by Altering the Gut Microbial Community.

Objective: To investigate the risk of colorectal cancer and its relationship with colonic flora and microenvironment under high-fat and high-calorie diet. Methods: Wistar rats were used to study, and they were given normal diet, high-fat diet, and dimethyl hydrazine (DMH) to induce the occurrence of colorectal cancer. Then observe the difference in tumor formation and the relationship among microbial community, inflammatory factors and metabolism. Results: No tumors were found in the normal diet group (G1) and the high-fat diet group (G3). Four nodules were found in the four rats in the normal diet + DMH group (G2) and 8 cancerous nodules were formed in 7 rats (70%) from high-fat diet + DMH group (G4). Cholesterol and TNF-α increased, IL-1, IL-6 and LEP decreased in the high-fat diet group. The difference was statistically significant. In the cancer-inducing group, only the difference in cholesterol was statistically significant. Compared with the normal diet group (G1) and the high-fat diet group (G3), the rat's gut bacterial abundance was not significantly different, but the gut flora structure was significantly changed. The content of Candida in the intestinal tract of rats in the high-fat diet group was reduced (P = 0.015), while the content of Verrucomicrobia increased (P = 0.035); In the comparison of genus content, Ruminococcus, Candida, Saccharibacteria genera incertae sedis, Enterobacter, Clostridium IV, Enterococcus, Enterorhabdus, Acetivibrio, Adlercreutzia, Lactococcus, etc., decreased significantly, while Akkermansia, Warthococcus, Staphylococcus, Butyricimonas, Clostridium XVIII, etc. increased significantly.Conclusion: This study found that high-fat, high-calorie diet can increase the susceptibility of the intestine to carcinogenic factors. The reason may be that the high-fat diet causes the body to appear inflammatory states and microbial community imbalance, especially rumenococcus, candida, Saccharomyces, Enterobacter, Clostridium IV, Enterococcus, Enterobacter, Vibrioaceticus and other genus reduction are important links. Exploring ways to improve these floras is an important factor to improve the resistance of the intestinal tract to cancer-inducing agents.

Positive effects of dietary supplementation of three probiotics on milk yield, milk composition and intestinal flora in Sannan dairy goats varied in kind of probiotics.

In this study, we investigated the effects of Saccharomyces cerevisiae (SC), Bacillus subtilis (BS) and Enterococcus faecalis (EF), singly and in combination, on the dry matter intake (DMI), milk production and composition, and faecal microflora of Saanen dairy goats. Fifty goats were randomly divided into five groups: (a) basal diet (control); (b) basal diet+SC; (c) basal diet+BS; (d) basal diet+EF; and (e) basal diet+mixed probiotics. Each treated animal received 5g/d of probiotics for a total administration of 5×1,011CFU/goat per day. The inclusion of B. subtilis and E. faecalis in the diet of lactating Saanen goats increased DMI (p<.05). Enhanced milk yield was observed with BS and EF. Milk fat percentage was significantly increased by feeding mixed probiotics compared with the control (p<.05); supplying SC, BS and mixed probiotics enhanced the protein percentage (p<.05). The milk lactose percentage in the SC and BS groups was higher than in the control (p<.05). The amount of milk total solids was higher after feeding EF or mixed probiotics than in the control group (p<.05). Non-fat solids showed no notable differences among groups (p>.05). There was no significant influence on gut bacterial abundance and diversity from adding these three probiotics, singly or in combination. Bacteroidales, Escherichia-Shigella and Christensenellaceae abundances were decreased by supplying these probiotics but Succinivibrionaceae increased. In conclusion, there were positive influences of probiotic feed supplementation on intake, milk performance and intestinal microecology.

Compositional analyses reveal correlations between taxon-level gut bacterial abundance and peripheral T cell marker expression in African infants

ABSTRACTAlthough exclusive breastfeeding has been linked to lower rates of postnatal HIV transmission compared to nonexclusive breastfeeding, mechanisms underlying this are unclear. Across a longitudinally sampled cohort of South African infants, we showed that exclusively breastfed (EBF) infants had altered gut bacterial communities when compared to nonexclusively breastfed (NEBF) infants, as well as reduced peripheral CD4 + T cell activation and lowered chemokine and chemokine receptor expression in the oral mucosa. We further demonstrated that the relative abundance of key taxa was correlated with peripheral CD4 + T cell activation. Here, we supplement those findings by using compositional data analyses to identify shifts in the abundance of several Bifidobacteria strains relative to select strains of Escherichia, Bacteroides, and others that are associated with the transition to NEBF. We illustrate that the abundance ratio of these taxa is tightly correlated with feeding modality and is a strong predictor of peripheral T cell activation. More broadly, we discuss our study in the context of novel developments and explore future directions for the field.

Lactobacillus plantarum MTCC 9510 supplementation protects from chronic unpredictable and sleep deprivation-induced behaviour, biochemical and selected gut microbial aberrations in mice.

Here, we evaluated any beneficial effects of a potential probiotic bacterial strain (Lactobacillus plantarum MTCC 9510) in two different stress paradigms in mice. Lactobacillus plantarum MTCC 9510 (2×1010 CFU per mice) was supplemented to male Swiss albino mice either subjected to chronic unpredictable mild stress or sleep deprivation (SD) stress. Various behavioural and biochemical tests along with selected gut bacterial abundances were determined. Lactobacillus plantarum MTCC 9510 supplementation prevented stress-induced behavioural despair (depression, anxiety, learning and memory, stereotypic behaviour), oxidative stress markers and inflammatory cytokines in brain and serum. Its supplementation also improved gut and blood brain barrier integrity. It also affected caecal short-chain fatty acids along with the promotion of Lactobacillus sp. and reduction in Enterobacteriaceae abundances. We also observed that two different stresses variably affected various behavioural and biochemical changes but L. plantarum MTCC 9510 supplementation most effectively prevented all these changes. We provide evidence that positive modulation of the selected beneficial gut microbial population could serve as a viable strategy to neutralize day-to-day and SD stress-induced pathological alterations. Therapeutic potential of this/other probiotic strains in tackling the deleterious neurobiological effects on exposure to various stress-related conditions can be explored.

Short‐term feeding of fermentable dietary fibres influences the gut microbiota composition and metabolic activity in rats

SummaryThis study investigated the effects of dietary fibres on gut bacterial abundance and metabolic activity in rats fed short‐term. Faecal samples from rats fed for 7 days showed differences in the effects of dietary fibres on gut bacterial populations. Broccoli fibre, inulin, potato fibre and potato resistant starch significantly increased the faecal Bacteroides‐Prevotella‐Porphyromonas group compared with cellulose. Growth of pathogenic bacteria such as Clostridium perfringens, Escherichia coli and Enterococcus spp. was decreased significantly in rats fed barley β‐glucan, citrus pectin, inulin and broccoli fibre diets. An increase in Bifidobacterium spp. and butyric acid levels, the so‐called bifidogenic and butyrogenic effects, was observed in rats fed inulin and potato fibre diets. Organic acid concentrations and polysaccharide contents in the rat faeces confirm the fermentability of dietary fibres in the gut. This study demonstrates the positive effects of plant‐sourced dietary fibres on gut microbiota composition and metabolic activity.