Lower Gut Research Articles

Neighborhood socioeconomic status and the human gut microbiome composition: relating socioeconomic environment to microbial diversity and MDRO colonization

Low socioeconomic status is correlated with a greater vulnerability to both chemical and non-chemical stressors, however, there is limited research on how socioeconomic status relates to the human gut microbiome, and subsequent associations with downstream health outcomes. Here, we aimed to examine associations between neighborhood level economic hardship, an indicator of overall cumulative risk, gut microbiome composition and additional cofactors that might be involved in this association including diet quality and food insecurity. We conducted a cross-sectional analysis of 721 adults living in geographically diverse (urban vs. rural) regions of Wisconsin (United States). 16S rRNA gene amplicons were analyzed from human stool samples using QIIME2 to evaluate both the composition and diversity of the gut microbiotas from 721 participants. Next, we determined correlations with each individual’s neighborhood score for socioeconomic status, or Economic Hardship Index (EHI), using simple and zero-inflated negative binomial regression models. Our model of EHI, with alpha diversity (Inverse-Simpson) as an outcome, found a correlation (β= 1.68, p=0.03) that it is partially mediated by food insecurity (p= 0.02). Moreover, we found differential abundances of known health-associated bacteria including members of the genera Bifidobacterium and Akkermansia, and the family Ruminococaceae between high and low levels of EHI that were robust to correction for multiple comparisons. Finally, we discovered a higher prevalence (p=0.03) and number (p=0.02) of multi-drug resistant bacteria isolated from individuals with low alpha-diversity and high EHI. Our analyses suggest that living in low socioeconomic communities is associated with lower gut microbial diversity and potential increase in colonization by multi-drug resistant microbial pathogens. Mediation of associations by food insecurity is consistent with previous work from our group examining impacts of metal exposures on gut microbiome dysbiosis indicating dietary factors play an important role in mitigating environmental influences on gut microbial diversity.

Siderophore Immunization Restricted Colonization of Adherent-Invasive Escherichia coli and Ameliorated Experimental Colitis.

ABSTRACTInflammatory bowel diseases (IBD) are characterized by chronic inflammation of the gastrointestinal tract and profound alterations to the gut microbiome. Adherent-invasive Escherichia coli (AIEC) is a mucosa-associated pathobiont that colonizes the gut of patients with Crohn’s disease, a form of IBD. Because AIEC exacerbates gut inflammation, strategies to reduce the AIEC bloom during colitis are highly desirable. To thrive in the inflamed gut, Enterobacteriaceae acquire the essential metal nutrient iron by producing and releasing siderophores. Here, we implemented an immunization-based strategy to target the siderophores enterobactin and its glucosylated derivative salmochelin to reduce the AIEC bloom in the inflamed gut. Using chemical (dextran sulfate sodium) and genetic (Il10−/− mice) IBD mouse models, we showed that immunization with enterobactin conjugated to the mucosal adjuvant cholera toxin subunit B potently elicited mucosal and serum antibodies against these siderophores. Siderophore-immunized mice exhibited lower AIEC gut colonization, diminished AIEC association with the gut mucosa, and reduced colitis severity. Moreover, Peyer’s patches and the colonic lamina propria harbored enterobactin-specific B cells that could be identified by flow cytometry. The beneficial effect of siderophore immunization was primarily B cell-dependent because immunized muMT−/− mice, which lack mature B lymphocytes, were not protected during AIEC infection. Collectively, our study identified siderophores as a potential therapeutic target to reduce AIEC colonization and its association with the gut mucosa, which ultimately may reduce colitis exacerbation. Moreover, this work provides the foundation for developing monoclonal antibodies against siderophores, which could provide a narrow-spectrum strategy to target the AIEC bloom in Crohn’s disease patients.

Comparison of the Gut Microbiome between Atopic and Healthy Dogs-Preliminary Data.

Simple SummaryAtopic dermatitis is a common inflammatory and itchy skin disease, constituting a global issue that affects up to 15% of the general human and dog population. The pathogenesis of this disease is known to be multifactorial and not only consisting of skin barrier dysfunction, but also with immunological dysregulation and skin microbiota changes having a central role. In humans, establishment of the gut microbiota in early life influences the development of allergies, among others also atopic dermatitis in children. To the author’s knowledge, there is currently no study comparing the gut microbiome between allergic and healthy dogs. We now present results demonstrating that allergic dogs have a significantly different gut microbiota when compared to healthy control dogs. Further investigations including a larger number of dogs are now required to confirm these results, in addition to studies utilizing novel interventions targeting the gut microbiota.Human studies show that in addition to skin barrier and immune cell dysfunction, both the cutaneous and the gut microbiota can influence the pathogenesis of atopic diseases. There is currently no data on the gut-skin axis in allergic canines. Therefore, the aim of this study was to assess the bacterial diversity and composition of the gut microbiome in dogs with atopic dermatitis (AD). Stool samples from adult beagle dogs (n = 3) with spontaneous AD and a healthy control group (n = 4) were collected at Days 0 and 30. After the first sampling, allergic dogs were orally dosed on a daily basis with oclacitinib for 30 days, and then re-sampled. Sequencing of the V3–V4 region of the 16S rRNA gene was performed on the Illumina MiSeq platform and the data were analyzed using QIIME2. The atopic dogs had a significantly lower gut microbiota alpha-diversity than healthy dogs (p = 0.033). In healthy dogs, a higher abundance of the families Lachnospiraceae (p = 0.0006), Anaerovoracaceae (p = 0.006) and Oscillospiraceae (p = 0.021) and genera Lachnospira (p = 0.022), Ruminococcus torques group (p = 0.0001), Fusobacterium (p = 0.022) and Fecalibacterium (p = 0.045) was seen, when compared to allergic dogs. The abundance of Conchiformibius (p = 0.01), Catenibacterium spp. (p = 0.007), Ruminococcus gnavus group (p = 0.0574) and Megamonas (p = 0.0102) were higher in allergic dogs. The differences in alpha-diversity and on the compositional level remained the same after 1 month, adding to the robustness of the data. Additionally, we could also show that a 4-week treatment course with oclacitinib was not associated with changes in the gut microbiota diversity and composition in atopic dogs. This study suggests that alterations in the gut microbiota diversity and composition may be associated with canine AD. Large-scale studies preferably associated to a multi-omics approach and interventions targeting the gut microbiota are needed to confirm these results.

Strongyloides stercoralis infection induces gut dysbiosis in chronic kidney disease patients.

Strongyloides stercoralis infection typically causes severe symptoms in immunocompromised patients. This infection can also alter the gut microbiota and is often found in areas where chronic kidney disease (CKD) is common. However, the relationship between S. stercoralis and the gut microbiome in chronic kidney disease (CKD) is not understood fully. Recent studies have shown that gut dysbiosis plays an important role in the progression of CKD. Hence, this study aims to investigate the association of S. stercoralis infection and gut microbiome in CKD patients. Among 838 volunteers from Khon Kaen Province, northeastern Thailand, 40 subjects with CKD were enrolled and divided into two groups (S. stercoralis-infected and -uninfected) matched for age, sex and biochemical parameters. Next-generation technology was used to amplify and sequence the V3-V4 region of the 16S rRNA gene to provide a profile of the gut microbiota. Results revealed that members of the S. stercoralis-infected group had lower gut microbial diversity than was seen in the uninfected group. Interestingly, there was significantly greater representation of some pathogenic bacteria in the S. stercoralis-infected CKD group, including Escherichia-Shigella (P = 0.013), Rothia (P = 0.013) and Aggregatibacter (P = 0.03). There was also a trend towards increased Actinomyces, Streptococcus and Haemophilus (P > 0.05) in this group. On the other hand, the S. stercoralis-infected CKD group had significantly lower representation of SCFA-producing bacteria such as Anaerostipes (P = 0.01), Coprococcus_1 (0.043) and a non-significant decrease of Akkermansia, Eubacterium rectale and Eubacterium hallii (P > 0.05) relative to the uninfected group. Interesting, the genera Escherichia-Shigella and Anaerostipes exhibited opposing trends, which were significantly related to sex, age, infection status and CKD stages. The genus Escherichia-Shigella was significantly more abundant in CKD patients over the age of 65 years and infected with S. stercoralis. A correlation analysis showed inverse moderate correlation between the abundance of the genus of Escherichia-Shigella and the level of estimated glomerular filtration rate (eGFR). Conclusion, the results suggest that S. stercoralis infection induced gut dysbiosis in the CKD patients, which might be involved in CKD progression.

Targeted suppression of human IBD-associated gut microbiota commensals by phage consortia for treatment of intestinal inflammation

Human gut commensals are increasingly suggested to impact non-communicable diseases, such as inflammatory bowel diseases (IBD), yet their targeted suppression remains a daunting unmet challenge. In four geographically distinct IBD cohorts (n= 537), we identify a clade of Klebsiella pneumoniae (Kp) strains, featuring a unique antibiotics resistance and mobilome signature, to be strongly associated with disease exacerbation and severity. Transfer of clinical IBD-associated Kp strains into colitis-prone, germ-free, and colonized mice enhances intestinal inflammation. Stepwise generation of a lytic five-phage combination, targeting sensitive and resistant IBD-associated Kp clade members through distinct mechanisms, enables effective Kp suppression in colitis-prone mice, driving an attenuated inflammation and disease severity. Proof-of-concept assessment of Kp-targeting phages in an artificial human gut and in healthy volunteers demonstrates gastric acid-dependent phage resilience, safety, and viability in the lower gut. Collectively, we demonstrate the feasibility of orally administered combination phage therapy in avoiding resistance, while effectively inhibiting non-communicable disease-contributing pathobionts.

Spotlight on the Gut Microbiome in Menopause: Current Insights.

The gut microbiome is an important contributor to human health, shaped by many endogenous and exogenous factors. The gut microbiome displays sexual dimorphism, suggesting influence of sex hormones, and also has been shown to change with aging. Yet, little is known regarding the influence of menopause – a pivotal event of reproductive aging in women – on the gut microbiome. Here, we summarize what is known regarding the interrelationships of female sex hormones and the gut microbiome, and review the available literature on menopause, female sex hormones, and the gut microbiome in humans. Taken together, research suggests that menopause is associated with lower gut microbiome diversity and a shift toward greater similarity to the male gut microbiome, however more research is needed in large study populations to identify replicable patterns in taxa impacted by menopause. Many gaps in knowledge remain, including the role the gut microbiome may play in menopause-related disease risks, and whether menopausal hormone therapy modifies menopause-related change in the gut microbiome. Given the modifiable nature of the gut microbiome, better understanding of its role in menopause-related health will be critical to identify novel opportunities for improvement of peri- and post-menopausal health and well-being.

In Utero Exposure to Caffeine and Acetaminophen, the Gut Microbiome, and Neurodevelopmental Outcomes: A Prospective Birth Cohort Study.

Pregnant individuals are exposed to acetaminophen and caffeine, but it is unknown how these exposures interact with the developing gut microbiome. We aimed to determine whether acetaminophen and/or caffeine relate to the childhood gut microbiome and whether features of the gut microbiome alter the relationship between acetaminophen/caffeine and neurodevelopment. Forty-nine and 85 participants provided meconium and stool samples at 6–7, respectively, for exposure and microbiome assessment. Fecal acetaminophen and caffeine concentrations were quantified, and fecal DNA underwent metagenomic sequencing. Caregivers and study staff assessed the participants’ motor and cognitive development using standardized scales. Prenatal exposures had stronger associations with the childhood microbiome than concurrent exposures. Prenatal acetaminophen exposure was associated with a trend of lower gut bacterial diversity in childhood [β = −0.17 Shannon Index, 95% CI: (−0.31, −0.04)] and was marginally associated with differences in the relative abundances of features of the gut microbiome at the phylum (Firmicutes, Actinobacteria) and gene pathway levels. Among the participants with a higher relative abundance of Proteobacteria, prenatal exposure to acetaminophen and caffeine was associated with lower scores on WISC-IV subscales. Acetaminophen during bacterial colonization of the naïve gut is associated with lasting alterations in childhood microbiome composition. Future studies may inform our understanding of downstream health effects.

Efficacy and safety of fecal microbiota transplantation for the induction of remission in active ulcerative colitis: a systematic review and meta-analysis of randomized controlled trials.

BackgroundFecal microbiota transplantation (FMT) is a novel management strategy for ulcerative colitis (UC). However, its effectiveness remains controversial. This study sought to assess the effectiveness of FMT in the treatment of active UC by performing a meta-analysis of randomized controlled trials (RCTs).MethodsWe searched the Cochrane, Embase, PubMed, and Web of Science databases from their inception to December 2021. RCTs that recruited patients with active UC and treated them with FMT, a placebo or a suitable comparator were included in the meta-analysis. PICOS: Patients, active UC; Intervention, FMT; Control, placebo or a suitable comparator; Outcomes, remission rate; Studies, RCTs. The risk of bias assessment was performed with Revised Cochrane risk-of-bias tool (version 2). Meta-analyses of risk ratios (RRs) were performed to estimate the differences in remission rates and the risk of serious adverse events (SAEs) between the FMT-treated and control patients.ResultsA total of 9 RCTs comprising 425 UC patients (213 FMT and 212 control) were included in the meta-analysis. The risk of bias was low in these RCTs. Clinical remission was observed in 86 of the 213 patients in the FMT groups and 47 of the 212 patients in the control groups [RR: 1.84; 95% confidence interval (CI): 1.37, 2.47; P<0.0001]. Clinical remission was better when the FMT delivery route was via the lower gut, the FMT dose was >300 grams, and the fecal specimen from multiple donors. Endoscopic remission (observed in 7 RCTs) was achieved in 33 of the 195 FMT-treated patients compared to 17 of the 194 control patients (RR: 1.94; 95% CI: 1.14, 3.31; P=0.01). SAEs were reported in 22 of the 213 FMT-treated patients but only 11 of the 212 control patients (RR: 2.05; 95% CI: 1.03, 4.09; P=0.04).DiscussionFMT is an effective treatment for patients with active UC. Significantly higher clinical and endoscopic remission rates are observed with FMT than with control treatments. However, FMT may cause a significantly higher incidence of SAEs than control treatments. Future studies should delineate the effects of donor selection, dosage, delivery route, and antibiotic pretreatment and should evaluate the safety profile of FMT.

A Green Tea Extract-Rich Confection in Healthy and Metabolic Syndrome Adults Decreases Small Intestinal Permeability in Association With Lower Gut Inflammation

ObjectivesPoor gut health, including increased intestinal permeability and inflammation, enhances cardiometabolic risk. Catechin-rich green tea extract (GTE) alleviates cardiometabolic complications in obese rodents by limiting gut permeability and inflammation, but whether these benefits occur in humans is not known. We hypothesized that the anti-inflammatory activities of GTE would decrease gut barrier dysfunction in persons at heightened cardiometabolic risk. MethodsIn a randomized, double-blind, placebo-controlled crossover study, persons with metabolic syndrome (MetS) and healthy persons completed two 4-wk interventions in which they received placebo or GTE confections (890 mg/d total catechins) while following a low-polyphenol diet. At wk 4, participants provided fecal samples for ELISA-based measures of inflammatory proteins. 24-h urine samples were also collected for LC/MS analysis of non-digestible sugars following the ingestion of lactulose (LAC), mannitol (MAN), sucralose (SUC), and erythritol (ERY). Data were analyzed by repeated measures ANOVA and linear regression controlling for within-subject repeated measures. ResultsMetS (n = 21; 40 ± 3 y; 35.2 ± 1.0 kg/m2) and healthy (n = 19; 34 ± 2 y; BMI = 22.3 ± 0.4 kg/m2) adults completed the study with no adverse effects, no changes in liver function tests, and > 95% compliance based on returned confections. Urinary SUC/ERY was unaffected by GTE and health status, but urinary LAC/MAN was lower (P = 0.043) in GTE compared with placebo regardless of health status. Fecal myeloperoxidase and calprotectin did not differ by health status, but were lower (P = 0.03–0.05) in response to GTE regardless of health status, and were positively correlated with each other (r = 0.75; P < 0.001). Fecal calprotectin and myeloperoxidase were both positively correlated with LAC/MAN ratio (r = 0.39–0.42; P = 0.01–0.02). ConclusionsInterim findings of this study support that dietary GTE decreases small intestinal permeability in association with lower gut inflammation, which may help to explain its known cardiometabolic benefits. Funding SourcesUSDA-NIFA (2019–67,017-29,259), USDA-HATCH, and the Ohio Agricultural Research and Development Center at The Ohio State University.

In vitro Fecal Fermentation of Indigestible Residues from Heat‐Moisture Treated Maize Meal and Maize Starch with Stearic Acid

AbstractThe effect of resistant starch type 5 (amylose‐lipid complex, ALC) from maize starch and maize meal on short‐chain fatty acids (SCFAs) production by in‐vitro human faecal fermentation are determined. The maize starch and meal are modified using heat‐moisture treatment (HMT), stearic acid (SA), and combination treatment (SA+HMT) and digested to obtain indigestible residues. The results showed the production of SCFAs (acetate, propionate, and butyrate) from indigestible residues containing amylose‐lipid complexes during the process of in vitro faecal fermentation. The concentrations of three SCFAs are lower than fructooligosaccharides (control) in most cases. In regard to the indigestible residues, the combination treatment has a significantly higher concentration of the total SCFAs than the individual SCFAs produced by different treatments and the control. Reduction in pH with increased gas production is observed. Acetate and butyrate levels are higher than propionate values of RS 5 from maize starch and meal. A positive correlation between the gas produced and SCFAs (acetate, propionate, and butyrate) is noticed, however it resulted in negative correlation with pH. In conclusion, indigestible residues containing ALC (or RS 5) produced SCFAs during in vitro faecal fermentation, suggesting that ALC are suitable substrates for fermentation in the lower gut.

Effects of Tannic Acid Supplementation on Growth Performance, Oocyst Shedding, and Gut Health of in Broilers Infected with Eimeria Maxima.

Simple SummaryE. maxima, an intracellular protozoan parasite propagating in the jejunum, can cause severe negative effects on growth and gut health of chickens. Tannic acid (TA), a polyphenol compound that can precipitate proteins, was hypothesized to control E. maxima infection and attenuate its negative effects in broilers due to their antimicrobial, antioxidative, and anti-inflammatory effects. Our study showed that supplementation of TA reduced oocyst shedding of E. maxima. Supplementation of TA at the level of 500 to 2750 mg/kg reduced gut permeability, increased nutrient digestibility, and improved intestinal development in broilers infected with E. maxima. However, supplementation of 5000 mg/kg TA showed anti-nutritional effects including reducing growth performance, increasing gut permeability, and decreasing nutrient digestibility in broilers infected with E. maxima. In summary, supplementation of TA at the level of 500 to 2750 mg/kg showed potential as an anti-coccidial agent by decreasing oocyst shedding and improving nutrient digestibility and intestinal integrity in broilers infected with E. maxima.The purpose of this study was to evaluate effects of tannic acid (TA) on growth performance, fecal moisture content, oocyst shedding, gut permeability, lesion score, intestinal morphology, apparent ileal digestibility, and the antioxidant and immune system of broilers infected with Eimeria maxima. A total of 420 one-day-old broilers were distributed to five treatments with seven replicates of 12 birds. The five treatments were the (1) sham-challenged control (SCC; birds fed a control diet and administrated with PBS); (2) challenged control (CC; birds fed a control diet and inoculated with E. maxima); (3) tannic acid 0.5 (TA0.5; CC + 500 mg/kg TA); (4) tannic acid 2.75 (TA2.75; CC + 2750 mg/kg TA); and (5) tannic acid 5 (TA5; CC + 5000 mg/kg TA). The TA2.75 group had significantly lower gut permeability compared to the CC group at 5 days post-infection (dpi). Supplementation of TA linearly reduced oocyst shedding of E. maxima at 7 to 9 dpi (p < 0.05). At 13 dpi, the TA2.75 group had significantly greater apparent ileal digestibility (AID) of dry matter (DM) and organic matter (OM) compared to the CC group. At 13 dpi, supplementation of TA linearly increased jejunal villus height (VH). Thus, this study showed that supplementation of TA at levels of 500 to 2750 mg/kg has the potential to be an anti-coccidial agent against E. maxima in broilers.

Gut Site and Gut Morphology Predict Microbiome Structure and Function in Ecologically Diverse Lemurs.

Most studies of wildlife gut microbiotas understandably rely on feces to approximate consortia along the gastrointestinal tract. We therefore compared microbiome structure and predicted metagenomic function in stomach, small intestinal, cecal, and colonic samples from 52 lemurs harvested during routine necropsies. The lemurs represent seven genera (Cheirogaleus, Daubentonia, Varecia, Hapalemur, Eulemur, Lemur, Propithecus) characterized by diverse feeding ecologies and gut morphologies. In particular, the hosts variably depend on fibrous foodstuffs and show correlative morphological complexity in their large intestines. Across host lineages, microbiome diversity, variability, membership, and function differed between the upper and lower gut, reflecting regional tradeoffs in available nutrients. These patterns related minimally to total gut length but were modulated by fermentation capacity (i.e., the ratio of small to large intestinal length). Irrespective of feeding strategy, host genera with limited fermentation capacity harbored more homogenized microbiome diversity along the gut, whereas those with expanded fermentation capacity harbored cecal and colonic microbiomes with greater diversity and abundant fermentative Ruminococcaceae taxa. While highlighting the value of curated sample repositories for retrospective comparisons, our results confirm that the need to survive on fibrous foods, either routinely or in hypervariable environments, can shape the morphological and microbial features of the lower gut.

Gut microbiota alterations in critically ill older patients: a multicenter study

BackgroundAging generates changes in the gut microbiota, affecting its functionality. Little is known about gut microbiota in critically ill older adults. The objective of this study was to describe the profile of gut microbiota in a cohort of critically ill older adults.MethodsThis observational study was conducted in five health institutions. Over a 6-month study period, critically ill patients over 18 years old who were admitted to the intensive care unit were enrolled. Fecal microbiota profiles were determined from 155 individuals, over 60 years old (n = 72) and under 60 years old (n = 83). Gut microbiota was analyzed by sequencing the V3-V4 region of the 16S rRNA gene. Alpha and beta diversity, operational taxonomic units and the interaction of gut microbiota with variables under study were analyzed. Amplicon sequence variants (ASVs) specifically associated with age were recovered by including gender, discharge condition, BMI, ICU stay and antibiotics as covariates in a linear mixed model.ResultsIn older adults, sepsis, malnutrition, antibiotic prescription and severity (APACHE and SOFA scores) were higher than in the group under 60 years of age. Alpha diversity showed lower gut microbiota diversity in those over 60 years of age (p < 0.05); beta diversity evidenced significant differences between the groups (PERMANOVA = 1.19, p = 0.038). The microbiota of the adults under 60 years old showed greater abundance of Murdochiella, Megasphaera, Peptoniphilus and Ezakiella, whereas those over 60 years old Escherichia-Shigella and Hungatella were more abundant.ConclusionThe gut microbial community was altered by different factors; however, age significantly explained the variability in critically ill patients. A lower presence of beneficial genera and a higher abundance of pathogens was observed in adults over 60 years old.

Associations Between Eczema and Attention Deficit Hyperactivity Disorder Symptoms in Children.

BackgroundEpidemiological studies suggest a link between eczema and attention deficit hyperactivity disorder (ADHD), but underlying mechanisms have not been examined.ObjectiveWe aim to investigate the association between eczema and subsequent ADHD symptoms in the Growing Up in Singapore Towards healthy Outcomes cohort and explore the role of pro-inflammatory cytokines and gut microbiome.MethodsThe modified International Study of Asthma and Allergies in Childhood questionnaire and Computerized Diagnostic Interview Schedule for Children Version IV were administered to assess reported eczema within the first 18 months and presence of ADHD symptoms at 54 months, respectively. Skin prick testing at 18 months, cytokines in maternal blood during pregnancy and cord blood and the mediating role of the gut microbiome at 24 months were assessed.ResultsAfter adjusting for confounders, eczema with or without a positive skin prick test was associated with doubling the risk of ADHD symptoms. No differences in maternal and cord blood cytokines were observed in children with and without eczema, or children with and without ADHD. Gut microbiome dysbiosis was observed in children with eczema and children with ADHD. Children with eczema also had lower gut bacterial Shannon diversity. However, the relationship between eczema and ADHD was not mediated by gut microbiome.ConclusionEarly life eczema diagnosis is associated with a higher risk of subsequent ADHD symptoms in children. We found no evidence for underlying inflammatory mechanism or mediation by gut microbiome dysbiosis. Further research should evaluate other mechanisms underlying the link between eczema and ADHD.Clinical Trial Registration[https://clinicaltrials.gov/ct2/show/NCT01174875], identifier [NCT01174875].

HISTO-AMELIORATIVE EFFECT OF PLEUROTUS TUBERREGIUM AGAINST LEAD INDUCED HEART, SPLEEN AND LOWER GUT DAMAGE IN ALBINO RAT

This study evaluates ameliorative effect of Pleurotus tuberregium on the effects of lead (Pb) using different concentrations of Pleurotus tuberregium /growers mash feed mixture in 90 Albino rats divided into six groups with three replicates (with 5 rats per group) for 21days pre-experimental stage for proper acclimatization. There after all the experimental groups were exposed to 0.1 g/l of lead daily for 21days. At the end of exposure period, lead salt was discontinued for 21and 42days post-experimental stage. Tissues of heart, spleen and lower gut were then collected and subsequently analyzed for the structural changes at every 21days interval. The tissues of the pre-experimental stages showed normal tissues as those of the control except in the lower gut which showed ileal mucosa with chronic inflammatory cell infiltration and muscularis propria. However, the experimental groups, showed observable damages to the tissues of heart (with transmural oedoma and myocardial degeneration, interstitial haemorrhage and coronary vascular hypertrophy), spleen(with focal activated follicles and sinus hyperplasia.) and lower gut (have ileal mucosa with focal atrophy and normal muscularis propria) which improved in the post experimental stages after 21 and 42 days with increased Pleurotus tuberregium content in the feed. The results of this study demonstrated that P .tuberregium may ameliorate lead toxicity in heart, spleen and lower gut tissues

Rumen and lower gut microbiomes relationship with feed efficiency and production traits throughout the lactation of Holstein dairy cows

Fermentation of dietary nutrients in ruminants' gastrointestinal (GI) tract is an essential mechanism utilized to meet daily energy requirements. Especially in lactating dairy cows, the GI microbiome plays a pivotal role in the breakdown of indigestible plant polysaccharides and supply most AAs, fatty acids, and gluconeogenic precursors for milk synthesis. Although the contribution of the rumen microbiome to production efficiency in dairy cows has been widely researched over the years, variations throughout the lactation and the lower gut microbiome contribution to these traits remain poorly characterized. Therefore, we investigated throughout lactation the relationship between the rumen and lower gut microbiomes with production efficiency traits in Holstein cows. We found that the microbiome from both locations has temporal stability throughout lactation, yet factors such as feed intake levels played a significant role in shaping microbiome diversity. The composition of the rumen microbiome was dependent on feed intake. In contrast, the lower gut microbiome was less dependent on feed intake and associated with a potentially enhanced ability to digest dietary nutrients. Therefore, milk production traits may be more correlated with microorganisms present in the lower gut than previously expected. The current study's findings advance our understanding of the temporal relationship of the rumen and lower gut microbiomes by enabling a broader overview of the gut microbiome and production efficiency towards more sustainable livestock production.

A Novel Approach for Monitoring the Volatile Metabolome in Biological Samples from Ruminants through Miniaturized Liquid-Liquid Extraction and Multiclass Gas Chromatography Analysis.

A straightforward and versatile methodology for the extraction of volatile metabolites in biological samples from ruminants for gas chromatography analysis is proposed. The methodology was applied in the determination of multiclass metabolites (short-chain fatty acids, aldehydes, alcohols, ketones, esters, phenols, and sulfides) in different analytical matrices (rumen fluid, urine, and feces) collected from Holstein cows. The 24 multiclass volatile metabolites reported in the different biological samples and their respective concentrations were critically discussed in the context of digestive physiology. Most detected compounds are derived from the rumen and lower gut fermentation of carbohydrates, proteins, and lipids or their metabolism, being consistent with the prior state of the art. The proposed method also takes advantage of the already existing tools in animal nutrition laboratories, providing a novel methodological ground that can generate relevant bioanalytical information with a significant impact on ruminant's nutritional studies.

Obesity mechanisms and importance of bioactive compounds from fruits in its regulation – a narrative review

A balanced diet is essential in obesity control. Fruits stand out for the presence of various bioactive compounds, which represent promising tools in the prevention and treatment of various pathologies. In obesity, fruits phytochemicals present are related to different important mechanisms of action, such as antioxidant and anti-inflammatory activity. This narrative review aims to understand the main physiological alterations of obesity and the effects of bioactive compounds in fruits on them, identifying the best-known substances and their likely mechanisms of action on the main biomarkers. The research was carried out in the Google Scholar, Scielo, Pubmed and Science Direct databases, considering reviews published since 2015 and experimental studies since 2010. Inflammatory cytokines and adipokines are considered primary biomarkers of obesity, and are currently also considered the insulin resistance, lower glucose tolerance, oxidative stress, gut microbiota, nutrients and microRNAs. Three groups of fruits stood out for their effects: Citrus fruits, berries and tropical fruits, sources mainly of flavonoids, anthocyanins and carotenoids. Experimental results indicate that fruits and their compounds can help in the prevention and treatment of obesity through the regulation of inflammatory cytokines and adipokines involved in the mechanisms of this disease, as well as antioxidant properties and modulation of lipogenesis. More clinical studies are needed to understand the biochemical mechanisms involved, in order to favor not only the production of specific supplements but also the best clinical dietary prescription.

Integration of rumen and lower gut microbiomes throughout lactation improve the prediction of feed efficiency and production traits in dairy cows (Supplemental Table 1)

Integration of rumen and lower gut microbiomes throughout lactation improve the prediction of feed efficiency and production traits in dairy cows (Supplemental Table 1)

Glucocorticoids coordinate changes in gut microbiome composition in wild North American red squirrels

The gut microbiome impacts host health and fitness, in part through the diversification of gut metabolic function and pathogen protection. Elevations in glucocorticoids (GCs) appear to reduce gut microbiome diversity in experimental studies, suggesting that a loss of microbial diversity may be a negative consequence of increased GCs. However, given that ecological factors like food availability and population density may independently influence both GCs and microbial diversity, understanding how these factors structure the GC-microbiome relationship is crucial to interpreting its significance in wild populations. Here, we used an ecological framework to investigate the relationship between GCs and gut microbiome diversity in wild North American red squirrels (Tamiasciurus hudsonicus). As expected, higher GCs predicted lower gut microbiome diversity and an increase in metabolic taxa. Surprisingly, but in line with prior empirical studies on wild animals, gastrointestinal pathogens decreased as GCs increased. Both dietary heterogeneity and an upcoming food pulse exhibited direct effects on gut microbiome diversity, whereas conspecific density and reproductive activity impacted diversity indirectly via changes in host GCs. Our results provide evidence of a gut–brain axis in wild red squirrels and highlight the importance of situating the GC-gut microbiome relationship within an ecological framework.