Genomic and functional analysis of Romboutsia ilealis CRIBT reveals adaptation to the small intestine

The Role of the Gut, Urine, and Vaginal Microbiomes in the Pathogenesis of Urinary Tract Infection in Women and Consideration of Microbiome Therapeutics

The gut, urine, and vaginal microbiomes play significant roles in the pathogenesis of recurrent urinary tract infections (rUTIs). Analysis of these microbiota has shown distinct associations with urinary tract infections. Encouraging data indicate that rUTIs may be responsive to microbiome treatments such as fecal microbiota transplantation, expanding potential treatments beyond antibiotics, hydration, and behavioral interventions. If successful, these nonantibiotic therapies have the potential to increase time between rUTI episodes and reduce the prevalence of multidrug-resistant organisms. In this review, we discuss the role of the 3 microbiomes in the pathogenesis of rUTI and utilization of live biotherapeutic products as therapy for rUTI.

Fecal microbiota transplantation accelerates restoration of florfenicol-disturbed intestinal microbiota in a fish model

Antibiotic-induced dysbiosis in the fish gut causes significant adverse effects. We use fecal microbiota transplantation (FMT) to accelerate the restoration of florfenicol-perturbed intestinal microbiota in koi carp, identifying key bacterial populations and metabolites involved in the recovery process through microbiome and metabolome analyses. We demonstrate that florfenicol disrupts intestinal microbiota, reducing beneficial genera such as Lactobacillus, Bifidobacterium, Bacteroides, Romboutsia, and Faecalibacterium, and causing mucosal injuries. Key metabolites, including aromatic amino acids and glutathione-related compounds, are diminished. We show that FMT effectively restores microbial populations, repairs intestinal damage, and normalizes critical metabolites, while natural recovery is less effective. Spearman correlation analyses reveal strong associations between the identified bacterial genera and the levels of aromatic amino acids and glutathione-related metabolites. This study underscores the potential of FMT to counteract antibiotic-induced dysbiosis and maintain fish intestinal health. The restored microbiota and normalized metabolites provide a basis for developing personalized probiotic therapies for fish.

Regulation of Fructose Metabolism in Nonalcoholic Fatty Liver Disease

Elevations in fructose consumption have been reported to contribute significantly to an increased incidence of obesity and metabolic diseases in industrial countries. Mechanistically, a high fructose intake leads to the dysregulation of glucose, triglyceride, and cholesterol metabolism in the liver, and causes elevations in inflammation and drives the progression of nonalcoholic fatty liver disease (NAFLD). A high fructose consumption is considered to be toxic to the body, and there are ongoing measures to develop pharmaceutical therapies targeting fructose metabolism. Although a large amount of work has summarized the effects fructose exposure within the intestine, liver, and kidney, there remains a gap in our knowledge regarding how fructose both indirectly and directly influences immune cell recruitment, activation, and function in metabolic tissues, which are essential to tissue and systemic inflammation. The most recent literature demonstrates that direct fructose exposure regulates oxidative metabolism in macrophages, leading to inflammation. The present review highlights (1) the mechanisms by which fructose metabolism impacts crosstalk between tissues, nonparenchymal cells, microbes, and immune cells; (2) the direct impact of fructose on immune cell metabolism and function; and (3) therapeutic targets of fructose metabolism to treat NAFLD. In addition, the review highlights how fructose disrupts liver tissue homeostasis and identifies new therapeutic targets for treating NAFLD and obesity.

Altered bile acid and correlations with gut microbiome in transition dairy cows with different glucose and lipid metabolism status

The transition from pregnancy to lactation is critical in dairy cows. Among others, dairy cows experience a metabolic stress due to a large change in glucose and lipid metabolism. Recent studies revealed that bile acids (BA), besides being involved in both the emulsification and solubilization of fats during intestinal absorption, can also affect the metabolism of glucose and lipids, both directly or indirectly by affecting the gut microbiota. Thus, we used untargeted and targeted metabolomics and 16S rRNA sequencing approaches to investigate the concentration of plasma metabolites and BA, the composition of the rectum microbial community, and assess their interaction in transition dairy cows. In Experiment 1, we investigated BA and other blood parameters and gut microbiota in dairy cows without clinical diseases during the transition period, which can be seen as well adapted to the challenge of changed glucose and lipid metabolism. As expected, we detected an increased plasma concentration of β-hydroxybutyrate (BHBA) and nonesterified fatty acids (NEFA) but decreased concentration of glucose, cholesterol, and triglycerides (TG). Untargeted metabolomic analysis of the plasma revealed primary BA biosynthesis was one of the affected pathways, and was consistent with the increased concentration of BA in the plasma. A correlation approach revealed a complex association between BA and microbiota with the host plasma concentration of glucose and lipid metabolites. Among BA, chenodeoxycholic acid derivates such as glycolithocholic acid, taurolithocholic acid, lithocholic acid, taurochenodeoxycholic acid, and taurodeoxycholic acid were the main hub nodes connecting microbe and blood metabolites (such as glucose, TG, and NEFA). In Experiment 2, we investigated early postpartum dairy cows with or without hyperketonemia (HPK). As expected, HPK cows had increased concentration of NEFA and decreased concentrations of glucose and triglycerides. The untargeted metabolomic analysis of the plasma revealed that primary BA biosynthesis was also one of the affected pathways. Even though the BA concentration was similar among the 2 groups, the profiles of taurine conjugated BA changed significantly. A correlation analysis also revealed an association between BA and microbiota with the concentration in plasma of glucose and lipid metabolites (such as BHBA). Among BA, cholic acid and its derivates such as taurocholic acid, tauro α-muricholic acid, and taurodeoxycholic acid were the main hub nodes connecting microbe and blood metabolites. Our results indicated an association between BA, intestinal microbe, and glucose and lipid metabolism in transition dairy cows. These findings provide new insight into the adaptation mechanisms of dairy cows during the transition period.

Deciphering Microbial Shifts in the Gut and Lung Microbiomes of COVID-19 Patients

COVID-19, caused by SARS-CoV-2, results in respiratory and cardiopulmonary infections. There is an urgent need to understand not just the pathogenic mechanisms of this disease but also its impact on the physiology of different organs and microbiomes. Multiple studies have reported the effects of COVID-19 on the gastrointestinal microbiota, such as promoting dysbiosis (imbalances in the microbiome) following the disease's progression. Deconstructing the dynamic changes in microbiome composition that are specifically correlated with COVID-19 patients remains a challenge. Motivated by this problem, we implemented a biomarker discovery pipeline to identify candidate microbes specific to COVID-19. This involved a meta-analysis of large-scale COVID-19 metagenomic data to decipher the impact of COVID-19 on the human gut and respiratory microbiomes. Metagenomic studies of the gut and respiratory microbiomes of COVID-19 patients and of microbiomes from other respiratory diseases with symptoms similar to or overlapping with COVID-19 revealed 1169 and 131 differentially abundant microbes in the human gut and respiratory microbiomes, respectively, that uniquely associate with COVID-19. Furthermore, by utilizing machine learning models (LASSO and XGBoost), we demonstrated the power of microbial features in separating COVID-19 samples from metagenomic samples representing other respiratory diseases and controls (healthy individuals), achieving an overall accuracy of over 80%. Overall, our study provides insights into the microbiome shifts occurring in COVID-19 patients, shining a new light on the compositional changes.

Association between labor epidural analgesia and gut microbiota: A prospective cohort study

Background

Labor epidural analgesia (LEA) may influence gut microbiota. We explored the association between LEA and gut microbiota for both mothers and their newborns.

Methods

In this prospective cohort study, parturients aged 25-35 years with a gestational age of 37-42 weeks and planned vaginal delivery were recruited. Twenty-one parturients received LEA (the LEA group), and 24 did not (the control group). Maternal and neonatal fecal samples were collected, and the gut microbiota profiles were analyzed using the 16S rRNA gene sequencing. The impact of LEA on gut microbiota was assessed using the general liner models.

Results

We showcased the gut microbiota profile from the phyla to species levels based on data on 45 mother-newborn dyads. The results of α- and β-diversity suggested significant changes in gut microbiota between the LEA and control groups. After adjusting for baseline confounders, the administration of LEA had positive correlations with R. ilealis (β = 91.87, adjusted P = 0.007) in mothers; LEA also had negative correlations with A. pittii (β = -449.36, adjusted P = 0.015), P. aeruginosa (β = -192.55, adjusted P = 0.008), or S. maltophilia (β = -142.62, adjusted P = 0.001) in mothers, and with Muribaculaceae (β = -2702.77, adjusted P = 0.003) in neonates.

Conclusion

LEA was associated with changes in maternal and neonatal gut microbiota, and future studies are still required to assess their impact on clinical outcomes and explore the mechanisms.

The association between serum heat shock protein 72 and intestinal permeability with intestinal microbiota and clinical severity in patients with cerebral infarction

Objectives

We aimed to compare serum heat shock protein 72 (HSP72) and intestinal permeability in patients with cerebral infarction (CI) and healthy individuals to reveal their correlations and link to gut microbiota alterations and clinical severity of CI.

Methods and results

Stool samples of 50 patients with CI and 46 healthy volunteers were analyzed through 16S rRNA gene sequencing to characterize intestinal flora profiles. Serum HSP72 and zonulin were assayed using enzyme-linked immunoassay (ELISA). The obtained data were then subjected to comparative and correlative analysis. We found that the levels of zonulin and serum HSP72 were significantly higher in the CI group compared to the healthy group. Serum HSP72 and zonulin levels were positively correlated in the CI group and correlated positively with the clinical severity of CI. β diversity showed significant differences in intestinal microbiota composition between the two groups. In the CI patient group, the abundance of bacteria Eubacterium_fissicatena_group, Eubacterium_eligens_group, and Romboutsia manifested a remarkably positive correlation with serum HSP72. The abundance of bacteria Eubacterium_fissicatena_group and Acetivibrio had a significantly positive correlation with zonulin levels.

Conclusion

Our findings indicated that an increase in serum HSP72 and zonulin levels was manifested in patients with CI and was related to specific gut microbiota alterations and the clinical severity of CI.

The metabolic benefits of substituting sucrose for maple syrup are associated with a shift in carbohydrate digestion and gut microbiota composition in high-fat high-sucrose diet-fed mice

Overconsumption of added sugars is now largely recognized as a major culprit in the global situation of obesity and metabolic disorders. Previous animal studies reported that maple syrup (MS) is less deleterious than refined sugars on glucose metabolism and hepatic health, but the mechanisms remain poorly studied. Beyond its content in sucrose, MS is a natural sweetener containing several bioactive compounds, such as polyphenols and inulin, which are potential gut microbiota modifiers. We aimed to investigate the impact of MS on metabolic health and gut microbiota in male C57Bl/6J mice fed a high-fat high-sucrose (HFHS + S) diet or an isocaloric HFHS diet in which a fraction (10% of the total caloric intake) of the sucrose was substituted by MS (HFHS + MS). Insulin and glucose tolerance tests were performed at 5 and 7 wk into the diet, respectively. The fecal microbiota was analyzed by whole-genome shotgun sequencing. Liver lipids and inflammation were determined, and hepatic gene expression was assessed by transcriptomic analysis. Maple syrup was less deleterious on insulin resistance and decreased liver steatosis compared with mice consuming sucrose. This could be explained by the decreased intestinal α-glucosidase activity, which is involved in carbohydrate digestion and absorption. Metagenomic shotgun sequencing analysis revealed that MS intake increased the abundance of Faecalibaculum rodentium, Romboutsia ilealis, and Lactobacillus johnsonii, which all possess gene clusters involved in carbohydrate metabolism, such as sucrose utilization and butyric acid production. Liver transcriptomic analyses revealed that the cytochrome P450 (Cyp450) epoxygenase pathway was differently modulated between HFHS + S- and HFHS + MS-fed mice. These results show that substituting sucrose for MS alleviated dysmetabolism in diet-induced obese mice, which were associated with decreased carbohydrate digestion and shifting gut microbiota.NEW & NOTEWORTHY The natural sweetener maple syrup has sparked much interest as an alternative to refined sugars. This study aimed to investigate whether the metabolic benefits of substituting sucrose with an equivalent dose of maple syrup could be linked to changes in gut microbiota composition and digestion of carbohydrates in obese mice. We demonstrated that maple syrup is less detrimental than sucrose on metabolic health and possesses a prebiotic-like activity through novel gut microbiota and liver mechanisms.

Sodium butyrate alleviates R97-116 peptide-induced myasthenia gravis in mice by improving the gut microbiota and modulating immune response

Fermented butyrate exhibits an anti-inflammatory response to maintain immune homeostasis within the gut. However, the effect and underlying mechanism of butyrate on myasthenia gravis (MG) remain unclear. The changes in the gut microbiota and fecal contents of SCFAs in MG patients were examined. R97-116 peptide was used to induce the experimental autoimmune myasthenia gravis (EAMG) mice and sodium butyrate (NaB) was gavaged to the EAMG mice. Gut microbiota, the frequency of Th1, Th17, Treg, Tfh, and B cells, the levels of IFN-γ, IL-17 A, IL-10, IL-21, and anti-R97-116 IgG, RNA-seq of total B cells in the spleen were explored by metagenomics, flow cytometry, ELISA, and transcriptomics. A significant reduction in SCFA-producing bacteria including Butyricimonas synergistica and functional modules including butyrate synthesis/production II was observed in MG patients and fecal SCFAs detection confirmed the increase. The EAMG mice were successfully constructed and NaB supplementation has changed the composition and function of the gut microbiota. The numbers of Th1, Th17, Tfh, and B cells were significantly increased while that of Treg cells was obviously decreased in EAMG mice compared with controls. Interestingly, NaB treatment has reduced the amounts of Th17, Tfh, and B cells but increased that of Treg cells. Accordingly, the levels of IL-17 A, IL-21, and IgG were increased while IL-10 was decreased in EAMG mice. However, NaB treatment reduced IL-17 A and IL-21 but increased that of IL-10. RNA-seq of B cells has revealed 4577 deferentially expressed genes (DEGs), in which 1218 DEGs were up-regulated while 3359 DEGs were down-regulated in NaB-treated EAMG mice. GO enrichment and KEGG pathway analysis unveiled that the function of these DEGs was mainly focused on immunoglobulin production, mitochondrial respiratory chain complex, ribosome, oxidative phosphorylation, and CNS diseases including amyotrophic lateral sclerosis. We have found that butyrate was significantly reduced in MG patients and NaB gavage could evidently improve MG symptoms in EAMG mice by changing the gut microbiota, regulating the immune response, and altering the gene expression and function of B cells, suggesting NaB might be a potential immunomodulatory supplement for MG drugs.

Effect of providing citrus pulp-integrated diet on fecal microbiota and serum and fecal metabolome shifts in crossbred pigs

The study aimed to assess the impact of dehydrated citrus pulp (DCP) on growth performance, fecal characteristics, fecal bacterial composition (based on 16S rRNA analysis), and fecal and serum metabolomic profiles in crossbred pigs. 80 finishing pigs Duroc × (Landrace × Large White) were fed either a control diet (C) or a diet with 240 g/kg DCP (T) for six weeks. Including DCP in diets tended to decrease feed intake, increased (p < 0.05) the concentrations of acetic and heptanoic acids and decreased (p < 0.05) fecal butyric and branched-chain fatty acid concentrations in feces. Animals fed DCP exhibited a lower abundance of the genera Clostridium and Romboutsia, while Lachnospira significantly increased. Orthogonal partial least squares discriminant analysis plotted a clear separation of fecal and serum metabolites between groups. The main discriminant fecal metabolites were associated with bacterial protein fermentation and were downregulated in T-fed pigs. In serum, DCP supplementation upregulated metabolites related to protein and fatty acids metabolism. In conclusion, the addition of DCP as an environmentally friendly source of nutrients in pig diets, resulted in modifications of fecal bacterial composition, fermentation patterns, and overall pig metabolism, suggesting improvements in protein metabolism and gut health.

Effects of microalgae as dietary supplement on palatability, digestibility, fecal metabolites, and microbiota in healthy dogs

The current trend of dog owners increasingly favoring the functional value of food to assure preventive health and wellbeing of their pets has been raising the interest in microalgae as natural additives with bioactive properties. However, scientific studies addressing the effects of microalgae supplementation in diets for dogs are scarce. This study aimed to evaluate the effects of dietary supplementation with three microalgae species (Chlorella vulgaris, Nannochloropsis oceanica, and Tetradesmus obliquus) on diet palatability, total tract digestibility, metabolizable energy content, fecal metabolites and microbiota of dogs. Twelve adult Beagle dogs were used in three two-bowl tests to compare the palatability of a commercial complete diet for adult dogs without (reference diet) and with 1.5% supplementation of each microalgae. From the results obtained, three digestibility trials were performed according to a replicated Latin square 3 × 3, with six adult Beagle dogs, three experimental periods of 10 days each, and three dietary supplementation levels of microalgae (0.5, 1.0, and 1.5%). In each trial, effects of microalgae supplementation levels on total tract digestibility, metabolizable energy content, fecal metabolites and microbiota of dogs were evaluated. First diet approached or tasted was not significantly affected by microalgae inclusion, but dogs showed a preference for the reference diet over the diets with 1.5% inclusion of C. vulgaris and N. oceanica, no difference being observed with 1.5% T. obliquus. In all digestibility trials, dietary supplementation with microalgae up to 1.5% did not greatly affected the dietary chemical composition and kept unaffected food intake, fecal output and metabolites, and digestibility of nutrients and energy. Compared with the reference diet, supplementation with C. vulgaris increased protein digestibility. Fecal characteristics and metabolites were affected by microalgae supplementation, being the effects dependent on the species. Fecal microbiota composition of dogs fed with microalgae-supplemented diets was modified by promoting the beneficial Turicibacter and Peptococcus genera associated with gut health and activation of the immune system. Overall, the results support C. vulgaris, N. oceanica, and T. obliquus as sustainable functional supplements that potentially enhance gastrointestinal health of dogs through the selective stimulation of microbiota without detrimental effects on food intake and digestibility.

Characteristics of gut microbiota in male periadolescent rats with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder, however, its effect on gut microbiota during the periadolescent period remains unclear. In this study, our objective was to investigate the characteristics of gut microbiota in male periadolescent rats with IBS induced by neonatal maternal separation (NMS). We evaluated visceral sensitivity by electromyography (EMG), analyzed gut microbiota composition using 16S rDNA gene sequencing, and examined intestinal pathological changes between control and IBS-like groups. The IBS-like group had significantly higher discharge amplitude of the external oblique muscle of the abdomen during colorectal distension (CRD) at 40- and 60 mmHg pressures. We observed differences in gut microbiota composition, with an increase in Bacteroidetes abundance and a decrease in Firmicutes in IBS-like rats. Beta-diversity analysis revealed the gut microbiota of the IBS-like group displayed higher consistent, while that of the control group exhibited substantial variation. Linear discriminant analysis effect size (LEfSe) detected 10 bacterial taxonomic clades showing statistically significant differences (7 increased and 3 decreased) in the IBS-like group. Functional analysis revealed that aminoacyl-tRNA biosynthesis and fatty acid biosynthesis were significantly altered, leading to changes in gene expression. Our findings demonstrate a definite correlation between gut microbiota dysbiosis and IBS during the male periadolescent period, with Alloprevotella and Bacteroide positively associated with high risk of IBS. The effects of specific bacterial genera may provide new insights for the development of treatments for IBS.

Almond (Prunus dulcis) Bagasse as a Source of Bioactive Compounds with Antioxidant Properties: An In Vitro Assessment

The presence of components of nutritional interest makes fresh almond bagasse an interesting by-product for obtaining functional ingredients. Stabilization through a dehydration process is an interesting option for its integral use, ensuring its conservation and management. Subsequently, it can be turned into powder, facilitating its use as an ingredient. The aim of this paper was to determine the effects of hot air drying at 60 and 70 °C and lyophilization on the release of phenolic components and antiradical capacity in in vitro gastrointestinal digestion and colonic fermentation, as well as on growing microbiota composition by applying high throughput sequencing. The novelty of this study lies in this holistic approach; considering both technological and physiological aspects related to gastrointestinal digestion and colonic fermentation will provide the best conditions for functional foods. The results obtained showed that lyophilization provides a powder with a total phenol content and antiradical capacity higher than hot air drying. Furthermore, in dehydrated samples, both in vitro digestion and colonic fermentation revealed a phenol content and anti-radical capacity superior to those existing in undigested products. In addition, after colonic fermentation, beneficial bacteria species have been identified. Obtaining powders from almond bagasse is presented as an interesting opportunity for the valorization of this by-product.

Effects of OsomeFood Clean Label plant-based meals on the gut microbiome

BACKGROUND

Plant-based diets offer more beneficial microbes and can modulate gut microbiomes to improve human health. We evaluated the effects of the plant-based OsomeFood Clean Label meal range ('AWE' diet), on the human gut microbiome.

METHODS

Over 21 days, ten healthy participants consumed OsomeFood meals for five consecutive weekday lunches and dinners and resumed their regular diets for other days/meals. On follow-up days, participants completed questionnaires to record satiety, energy and health, and provided stool samples. To document microbiome variations and identify associations, species and functional pathway annotations were analyzed by shotgun sequencing. Shannon diversity and regular diet calorie intake subsets were also assessed.

RESULTS

Overweight participants gained more species and functional pathway diversity than normal BMI participants. Nineteen disease-associated species were suppressed in moderate-responders without gaining diversity, and in strong-responders with diversity gains along with health-associated species. All participants reported improved short-chain fatty acids production, insulin and γ-aminobutyric acid signaling. Moreover, fullness correlated positively with Bacteroides eggerthii; energetic status with B. uniformis, B. longum, Phascolarctobacterium succinatutens, and Eubacterium eligens; healthy status with Faecalibacterium prausnitzii, Prevotella CAG 5226, Roseburia hominis, and Roseburia sp. CAG 182; and overall response with E. eligens and Corprococcus eutactus. Fiber consumption was negatively associated with pathogenic species.

CONCLUSION

Although the AWE diet was consumed for only five days a week, all participants, especially overweight ones, experienced improved fullness, health status, energy and overall responses. The AWE diet benefits all individuals, especially those of higher BMI or low-fiber consumption.

Effects of paraprobiotics on bile acid metabolism and liver health in largemouth bass (Micropterus salmoides) fed a cottonseed protein concentrate-based diet

Cottonseed protein concentrate is a sustainable fishmeal alternative in aquafeed. A 10-week experiment was conducted to investigate the effects of a cottonseed protein concentrate-based diet with and without multi-strain yeast fractions (MsYF) on growth, bile acid metabolism, and health in largemouth bass. Four hundred fish (54.0 ± 0.0 g) were casually distributed into 16 tanks (4 replicates/diet). Fish were fed with 4 iso-nitrogen and iso-energetic diets 3 times daily, including a fishmeal diet (FM), a soy protein concentrate-based diet (SPC; replacing 81% fishmeal protein), a cottonseed protein concentrate-based diet (CPC; replacing 81% fishmeal protein), and a CPC diet supplemented with 800 mg/kg MsYF (CPCY). Results showed that the survival of SPC was the lowest, i.e., 48%, with no apparent diet effect among other treatments; we omitted the SPC in additional analyses. Fish fed cottonseed protein concentrate-based diets showed lower growth than FM (P < 0.05). Fish fed CPC showed the highest nuclear dense hepatic phenotypes ratio (50%), followed by CPCY (33%) and FM (17%). Further, dietary CPC increased hepatic total cholesterol and triglyceride levels with concurrently increased cholesterol synthesis but decreased triglyceride synthesis-associated transcription levels (P < 0.05). Furthermore, dietary CPC increased bile acid synthesis but decreased bile acid transport-associated transcription levels (P < 0.05), and then induced an increment of plasma cholic acid and hepatic chenodeoxycholic acid content and the decrement of genus Romboustia (P < 0.05). Regarding the effect of MsYF, fish fed CPCY reduced hepatic lipid accumulation and total plasma bile acid content (P < 0.05) compared to CPC, suggesting an improvement in liver health. Also, dietary MsYF could reverse the microbiota community structure showing a similar gut microbial composition to FM. In conclusion, 81% of fishmeal protein replaced by cottonseed protein concentrate suppressed growth and liver health, while dietary MsYF might mitigate the negative impact of a high cottonseed protein concentrate level diet on liver functions via gut microbiota regulation.

Combined effects of sodium butyrate and xylo-oligosaccharide on growth performance, anti-inflammatory and antioxidant capacity, intestinal morphology and microbiota of broilers at early stage

This study aimed to evaluate the individual and combined effects of chemically protected sodium butyrate (CSB) and xylo-oligosaccharide (XOS) on performance, anti-inflammatory and antioxidant capacity, intestinal morphology and microbiota of broilers. A total of 280 one-day-old Arbor Acres broilers were randomly distributed into 5 treatments: basal diet (CON), basal diet supplemented with 100 mg/kg aureomycin and 8 mg/kg enramycin (ABX), 1000 mg/kg CSB (CSB), 100 mg/kg XOS (XOS), and mixture of 1000 mg/kg CSB and 100 mg/kg XOS (MIX), respectively. On d 21, ABX, CSB, and MIX decreased feed conversion ratio compared with CON (CON: ABX: CSB: MIX = 1.29: 1.22: 1.22: 1.22), whereas body weight of CSB and MIX was increased by 6.00% and 7.93%, and average daily gain was increased by 6.62% and 8.67% at 1-21 d, respectively (P < 0.05). The main effect analysis showed that both CSB and XOS treatments increased ileal villus height and villus height to crypt depth ratio (VCR) (P < 0.05). Moreover, broilers in ABX showed lower 21.39% ileal crypt depth and higher 31.43% VCR than those in CON (P < 0.05). Dietary CSB and XOS were added individually or collectively increased total antioxidant capacity and superoxide dismutase, and anti-inflammatory cytokines interleukin-10 and transforming growth factor-β, whereas decreased malondialdehyde, and proinflammatory cytokines IL-6 and tumor necrosis factor-α content in serum (P < 0.05). Meanwhile, MIX showed the best effect of antioxidant and anti-inflammatory capacity among the 5 groups (P < 0.05). There was an interaction between CSB and XOS treatments on increasing cecal acetic acid, propionic acid, butyric acid and total short-chain fatty acid (SCFA) (P < 0.05), and the one-way ANOVA showed that propionic acid in CSB was 1.54 times that of CON, whereas butyric acid and total SCFAs in XOS were 1.22 times and 1.28 times that of CON, respectively (P < 0.05). Furthermore, dietary combination of CSB and XOS changed phyla Firmicutes and Bacteroidota, and increased genera Romboutsia and Bacteroides (P < 0.05). In conclusion, dietary CSB and XOS improved growth performance of broilers, and the combined addition of them had the best effect on anti-inflammatory and antioxidant capacity, and intestinal homeostasis of broilers in current study, indicating that it may be a potential natural alternative to antibiotics.

Gamma-Aminobutyric Acid Promotes Beige Adipocyte Reconstruction by Modulating the Gut Microbiota in Obese Mice

Given the increasing prevalence of obesity, the white-to-beige adipocyte conversion has attracted interest as a target for obesity treatment. Gamma-aminobutyric acid (GABA) treatment can reduce obesity, but the underlying mechanism remains unclear. Here, we aimed to investigate the mechanism by which GABA triggers weight loss by improving the beiging of inguinal white adipose tissue (iWAT) and the role of gut microbiota in this process. The results showed that GABA reduced body weight and adipose inflammation and promoted the expression of thermogenic genes in the iWAT. The 16S rRNA sequence analysis of gut microbiota showed that GABA treatment increased the relative abundance of Bacteroidetes, Akkermansia, and Romboutsia and reduced that of Firmicutes and Erysipelatoclostridium in obese mice. Additionally, serum metabolomic analysis revealed that GABA treatment increased 3-hydroxybutyrate and reduced oxidized lipid levels in obese mice. Spearman's correlation analysis showed that Akkermansia and Romboutsia were negatively associated with the levels of oxidized lipids. Fecal microbiota transplantation analysis confirmed that the gut microbiota was involved in the white-to-beige adipocyte reconstruction by GABA. Overall, our findings suggest that GABA treatment may promote iWAT beiging through the gut microbiota in obese mice. GABA may be utilized to protect obese people against metabolic abnormalities brought on by obesity and gut dysbiosis.

Alteration of the gut microbiota and metabolite phenylacetylglutamine in patients with severe chronic heart failure

Chronic Heart Failure (CHF) is the end result of nearly all cardiovascular disease and is the leading cause of deaths worldwide. Studies have demonstrated that intestinal flora has a close relationship with the development of Cardiovascular Disease (CVD) and plays a vital role in the disease evolution process. Phenylacetylglutamine (PAGln) a metabolite of the intestinal flora, is one of the common chronic kidney disease toxins. Its concentrations in plasma were higher in patients with major adverse cardiovascular events (MACE) however, its variation in patients with various degrees of CHF has rarely been reported. Therefore, we collected stool and plasma samples from 22 healthy controls, 29 patients with NYHA Class III and 29 patients with NYHA Class IV CHF (NYHA stands for New York Heart Association) from the Department of Cardiology of Shanghai Fengxian District Central Hospital. Next, we analyzed these samples by performing bacterial 16S ribosomal RNA gene sequencing and liquid chromatography tandem mass spectrometry. The result shows: The Chao 1 index was significantly lower in both NYHA class III and NYHA class IV than it was in the control group. The beta diversity was substantially dissimilar across the three groups. The linear discriminant analysis effect size analysis (LEfSe) showed that the bacterial species with the largest differences were Lachnospiraceae in control group, Enterobacteriaceae in NYHA class III, and Escherichia in NYHA class IV. The concentration of PAGln was significantly different between CHF and control groups and increased with the severity of heart failure. Finally, the correlation analysis represented that Parabacteroides and Bacteroides were negatively correlated to brain natriuretic peptide (BNP) and PAGln; Romboutsia and Blautia adversely associated with PAGln; Klebsiella was positively interrelated with BNP; Escherichia-Shigella was positively correlated with PAGln and BNP; Alistipes was contrasted with BNP; and Parabacteroides was negatively correlated with the left ventricular end-diastolic diameter (LVEDD). This study presented that the intestinal flora and its metabolite PAGln were altered with different grades of CHF and illustrated the effects of the gut flora and its metabolite on CHF.

Alterations in Healthy Adult Canine Faecal Microbiome and Selected Metabolites as a Result of Feeding a Commercial Complete Synbiotic Diet with Enterococcus faecium NCIMB 10415

In dogs, the use of probiotics for preventive or therapeutic purposes has become increasingly common, however the evidence for beneficial effects are often limited. The aim of this study was to investigate the effects of feeding a diet containing Enterococcus faecium NCIMB 10415 on faecal quality, faecal short-chain fatty acid concentrations, serum concentrations of cholesterol, triglycerides, cobalamin and folate as well as faecal microbiome in adult dogs. Eleven healthy client owned dogs were enrolled in a randomized, double-blinded crossover study. All dogs were fed the same balanced diet with or without incorporation of Enterococcus faecium NCIMB 10415 for 16 days each. Blood and faecal samples were collected at baseline and during the feeding trial and owners recorded daily faecal scores. An Enterococcus spp. ASV, likely representing E. faecium NCIMB 10415 was detected in the faecal microbiome of some dogs 18-19 days after withdrawal of oral supplementation. Inclusion of E. faecium decreased circulating cholesterol (p = 0.008) compared to baseline. There were no differences in cholesterol concentrations between diets. Owners reported 0.6 ± 0.3) days less of loose stools compared to the control diet. Comparing to baseline, both diets significantly increased faecal concentration of acetate and butyrate, decreased serum cobalamin and increased faecal microbial diversity. Decreased serum cobalamin, and increased faecal acetate correlated with decreases in the Fusobacterium, Streptococcus, Blautia, and Peptoclostridium. Except for effects on circulating cholesterol and faecal score, effects were observed regardless of the addition of E. faecium. It is therefore likely that these effects can be contributed to dietary prebiotic effects on the faecal microbiome.

Delivery of streptomycin to the rat colon by use of electrospun nanofibers

Drug-loaded electrospun nanofibers are potential drug carrier systems that may optimize disease treatment while reducing the impact on commensal microbes. The feasibility of streptomycin-loaded pullulan nanofibers fabricated from a green electrospinning procedure using water as the solvent was assessed. We conducted a rat study including a group treated with streptomycin-loaded nanofibers (STR-F, n = 5), a group treated with similar concentrations of streptomycin in the drinking water (STR-W, n = 5), and a non-treated control group (CTR, n = 5). Streptomycin was successfully loaded into nanofibers and delivered by this vehicle, which minimized the quantity of the drug released in the ileal compartment of the gut. Ingested streptomycin-resistant E. coli colonized of up to 10⁶ CFU/g feces, revealing a selective effect of streptomycin even when given in the low amounts allowed by the nanofiber-based delivery. 16S amplicon sequencing of the indigenous microbiota revealed differential effects in the three groups. An increase of Peptostreptococcaceae in the cecum of STR-F animals may indicate that the fermentation of nanofibers directly or indirectly promoted growth of bacteria within this family. Our results elucidate relevant properties of electrospun nanofibers as a novel vehicle for delivery of antimicrobials to the large intestine.

Characterization and Dynamics of the Gut Microbiota in Rice Fishes at Different Developmental Stages in Rice-Fish Coculture Systems

The rice-fish system (RFS), a traditional coculture farming model, was selected as a "globally important agricultural heritage system." Host-associated microbiota play important roles in development, metabolism, physiology, and immune function. However, studies on the gut microbiota of aquatic animals in the RFS are scarce, especially the lack of baseline knowledge of the dynamics of gut microbial communities in rice fish during different developmental stages. In this study, we characterized the microbial composition, community structure, and functions of several sympatric aquatic animals (common carp (Cyprinus carpio), crucian carp (Carassius carassius), and black-spotted frogs (Pelophylax nigromaculatus)), and the environment (water) in the RFS using 16S rRNA gene sequencing. Moreover, we investigated stage-specific signatures in the gut microbiota of common carp throughout the three developmental stages (juvenile, sub-adult, and adult). Our results indicated that the Fusobacteriota, Proteobacteria, and Firmicutes were dominant gut microbial phyla in rice fish. The differences in gut microbial compositions and community structure between the three aquatic species were observed. Although no significant differences in alpha diversity were observed across the three developmental stages, the microbial composition and community structure varied with development in common carp in the RFS, with an increase in the relative abundance of Firmicutes in sub-adults and a shift in the functional features of the community. This study sheds light on the gut microbiota of aquatic animals in the RFS. It deepens our understanding of the dynamics of gut microflora during common carp development, which may help improve aquaculture strategies in the RFS.

Unveiling of dietary and gut-microbiota derived B vitamins: Metabolism patterns and their synergistic functions in gut-brain homeostasis

Nutrition-gut cross-talk holds a vital position in sustaining intestinal function, and micronutrient metabolism has emerged as the foremost metabolic pathway to preserve gut homeostasis. Among micronutrients, B vitamins have evolved prior to DNA/RNA and are known for their vital roles for major evolutionary transitions in extant organisms. Despite their universal requirement and critical role, not all the three domains of life are endowed with a natural ability for de novo B vitamins synthesis. The human gut microbiome constitutes prototrophs and auxotroph which are entirely dependent on dietary intake and gut microbial production of B vitamins. The syntrophic metabolism involving cross-feeding of B vitamins and community-wide exchange between commensal bacteria elicit important changes in the diversity and composition of the human gut microbiome. Hereto, we discuss the B-vitamins sharing among prototrophic and auxotrophic gut bacteria, their absorption in small intestine and transport in distal gut, functional role in relation to the gut homeostasis and symptoms linked to their deficiency. We also briefly explore their potential involvement as psychobiotics in brain energetic metabolism (kynurenines/tryptophan pathway) for neurological functions and highlight their deficiency related malfunctioning.

Effects of Lysophosphatidylcholine on Intestinal Health of Turbot Fed High-Lipid Diets

An 8-week feeding trial was conducted, where turbot were fed four experimental diets, containing different LPC levels (0%, 0.1%, 0.25%, and 0.5%, named LPC0, LPC0.1, LPC0.25, and LPC0.5, respectively). The intestinal morphology results showed that there were no widened lamina propria and mixed inflammatory cells in the LPC-supplemented groups. Dietary LPC remarkably decreased the expression of TLRs (TLR3, TLR8, TLR9, and TLR22), MyD88, and signaling molecules (NF-κB, JNK, and AP-1). Similarly, diets with LPC supplementation markedly depressed the gene expression of NF-κB and JNK signaling pathway downstream genes (TNF-α, IL-1β, Bax, Caspase9, and Caspase-3). Furthermore, dietary LPC modified the intestinal microbial profiles, increasing the relative abundance of short-chain fatty acids-producers, lactic acid bacteria, and digestive enzyme-producing bacteria. Predictive functions of intestinal microbiota showed that turbot fed LPC diets had a relatively higher abundance of functions, such as lipid metabolism and immune system, but a lower abundance of functions, such as metabolic diseases and immune system diseases. The activities of intestinal acid phosphatase and alkaline phosphatase were also increased by dietary LPC. In conclusion, LPC supplementation could regulate the intestinal mucosal barrier via the TLR signaling pathway and alter the intestinal microbiota profile of turbot fed high-lipid diets.

The gastrointestinal microbiome of browsing goats (Capra hircus)

Despite the growing interest in the ruminants' gastrointestinal tract (GIT) microbiomes' ability to degrade plant materials by animal husbandry and industrial sectors, only a few studies addressed browsing ruminants. The present work describes the taxonomic and functional profile of the bacterial and archaeal communities from five different gastrointestinal sections (rumen, omasum-abomasum, jejunum, cecum and colon) of browsing Capra hircus, by metabarcoding using 16S rRNA genes hypervariable regions. The bacterial communities across the GITs are mainly composed of Bacillota and Bacteroidota. Prevotella was the leading bacterial group found in the stomachs, Romboutsia in the jejuna, and Rikenellaceae_RC9_gut_group, Bacteroides, UCG-010_ge, UCG-005, and Alistipes in large intestines. The archaeal communities in the stomachs and jejuna revealed to be mainly composed of Methanobrevibacter, while in the large intestines its dominance is shared with Methanocorpusculum. Across the GITs, the main metabolic functions were related to carbohydrate, amino acid, and energy metabolisms. Significant differences in the composition and potential biological functions of the bacterial communities were observed among stomachs, jejuna and large intestines. In contrast, significant differences were observed among stomachs and jejuna verse large intestines for archaeal communities. Overall different regions of the GIT are occupied by different microbial communities performing distinct biological functions. A high variety of glycoside hydrolases (GHs) indispensable for degrading plant cell wall materials were predicted to be present in all the GIT sections.

Fish gut-associated bacterial communities in a tropical lagoon (Aghien lagoon, Ivory Coast)

Aghien lagoon (Ivory Coast) is a eutrophic freshwater lagoon that harbors high biomasses of phytoplankton. Despite Increasing interest in fish gut microbiomes diversity and functions, little data is currently available regarding wild species from tropical west African lakes. Here, gut-associated bacterial communities are investigated in four fish species that are consumed by locale populations, namely the Cichlidae Hemichromis fasciatus, Tilapia guineensis and Sarotherodon melanotheron, and the Claroteidae Chrysichthys nigrodigitatus. Species-related differences are identified, that can be attributed to host phylogeny and diet. Important variations throughout the year are observed in T. guineensis and C. nigrodigitatus. This result emphasized the importance of time-series sampling and comparison with environmental variables even in tropical regions, that are not often conducted in wild populations. Effects of environmental factors (anthropogenic or not) on the microbiota and potential outcomes for fish health and populations sustainability need to be further explored. Interestingly, fish appear as major reservoirs of bacterial diversity, suggesting that they could contribute to the overall stability and resilience of bacterial communities present in the Aghien lagoon.

Differential regulation and preventive mechanisms of green tea powder with different quality attributes on high-fat diet-induced obesity in mice

Tea powder has been reported to have some physiological functions. However, there is no report on whether there are differences in the active ingredients of tea powder with different qualities and whether there are different prebiotic mechanisms. This study was aimed to investigate the effects of different qualities of tea powder on preventing obesity from different aspects, namely antioxidation, inflammation, lipid-lowering, and intestinal flora, using an obesity mouse model. The results showed that all three types of tea powder with different qualities could reduce body weight and decrease serum TC, TG, and LDL-C. However, tea powder with different quality attributes exhibited diverse modulatory effects and mechanisms. Tender tea powder contained more tea polyphenols, and it had a better effect on improving oxidative stress. Tender tea powder significantly decreased the abundances of Blautia, Bilophila, and Oscillibacter, and increased the abundances of Alloprevotella, Lachnoclostridium, Romboutsia, and Ruminococcaceae_UCG-004. Coarse tea powder contained more dietary fiber, and had a better effect on reducing the food intake and improving lipid metabolism, which could reduce lipid synthesis and increase lipid β-oxidation. Coarse tea powder significantly decreased the abundance of Dubosiella and increased the abundances of the Lachnospiraceae_NK4A136 group and Coriobacteriaceae_UCG-002. Our findings provide a theoretical reference for the comprehensive utilization of tea powder.

C-phycocyanin alleviated cisplatin-induced oxidative stress and inflammation via gut microbiota—metabolites axis in mice

C-phycocyanin is a natural protein extracted from Spirulina platensis. We aim to investigate the preventive effect of C-phycocyanin on cisplatin chemotherapy-induced oxidative damage and inflammation. The result showed that C-phycocyanin treatment reduced cisplatin-induced mortality and inflammation including decreased levels of serum IL6, kidney MCP1, and liver IL1β. Furthermore, C-phycocyanin also exerted antioxidant effects on mice, including increased GSH-Px, GGT, and GSH levels in the liver and increased CAT and SOD levels in the kidney. HepG2 cells experiments showed that C-phycocyanin exhibited none of the prevention effects on cisplatin injury. Faecalibaculum showed the greatest reduction among genera after cisplatin treatment, which was related to the enrichment of Romboutsia and Lactobacillus genera. C-phycocyanin treatment reduced the populations of harmful bacteria of Enterococcus faecalis, which was positively correlated with inflammation induced by cisplatin. C-phycocyanin increased the contents of 23-nordeoxycholic acid and β-muricholic acid. Moreover, C-phycocyanin increased amino acid-related metabolites, Nα-acetyl-arginine and trimethyl-lysine contents, and decreased fatty acid esters of hydroxy fatty acids (FAHFAs) contents. In conclusion, C-phycocyanin inhibited inflammation via the 23-nordeoxycholic acid-Enterococcus faecalis-inflammation axis, and enhanced the antioxidant capacity of kidney via Lactobacillus-NRF2 pathway. C-phycocyanin alleviated cisplatin injury via the modulation of gut microbiota, especially Lactobacillus and Enterococcus, as well as regulation of metabolites, especially bile acid and FAHFAs, which highlight the effect of C-phycocyanin and provide a new strategy to prevent cisplatin injury.

Specific gut microbiota alterations in essential tremor and its difference from Parkinson's disease

Essential tremor (ET) is the most common movement disorder and share overlapping symptoms with Parkinson’s disease (PD), making differential diagnosis challenging. Gut dysbiosis is regarded crucial in the pathogenesis of PD. Since ET patients also has comorbidity in gastrointestinal disorders, the relationship between gut microbiota and ET really worth investigating and may help distinguishing ET from PD. Fecal samples from 54 ET, 67 de novo PD and 54 normal controls (NC) were collected for 16S ribosomal RNA gene sequencing and quantitative real-time PCR. ET showed lower species richness (Chao1 index) than NC and PD. ET was with Bacteroides-dominant enterotype, while PD was with Ruminococcus-dominant enterotype. Compared with NC, 7 genera were significantly reduced in ET, 4 of which (Ruminococcus, Romboutsia, Mucispirillum, and Aeromonas) were identified to be distinctive with an area under the curve (AUC) of 0.705. Compared to PD, 26 genera were found significantly different from ET, 4 of which (Bacteroides, Fusobacterium, Phascolarctobacterium, and Lachnospira) were found distinguishable with an AUC of 0.756. Clinical association results indicated that Proteus was associated with disease severity (TETRAS) of ET, while Klebsiella was linked to depression and anxiety in ET. Functional predictions revealed that 4 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were altered in ET. This study reveals gut dysbiosis in ET and it provides new insight into the pathogenesis of ET and helps distinguishing ET from PD.

The effects of fish meal substitution by clam meal on the growth and health of Florida pompano (Trachinotus carolinus)

A 12-week feeding trial was conducted to evaluate the effects of fish meal (FM) substitution by clam meal (CM, at 10%, 20% and 30% of the diet) on the growth, feed utilization, hepatic antioxidant enzymes, plasma parameters, fatty acid and amino acid composition, and gut microbiome of juvenile Florida pompano, Trachinotus carolinus. The results indicated that: (1) juveniles fed 10% and 20% CM had a significantly higher final weight than the group fed the control (0% CM); and the control group also showed significantly lower weight gain, feed intake, protein retention value, whole-body crude protein and total amino acids composition, but higher hepatosomatic index and whole-body crude fat; (2) hepatic peroxide content and superoxide dismutase activity were not significantly affected by the substitution of CM, but it did affect glutathione peroxidase activity, with higher levels found in fish fed 30% CM compared to 0% and 10% CM; (3) plasma total protein, alkaline phosphatase, alanine aminotransferase, and immunoglobulin M showed no significant differences among the treatments; (4) there were no significant differences among treatments in terms of fatty acids composition and microbial diversity. Overall, this study concluded that CM has comparable benefit in the diet of Florida pompano as FM does.

Pot-pollen supplementation reduces fasting glucose and modulates the gut microbiota in high-fat/high-sucrose fed C57BL/6 mice

Pot-pollen is a mixture of pollen and nectar from flowers combined with salivary substances of stingless bees, which together are fermented inside cerumen pots. As pot-pollen is rich in polyphenols, we hypothesized that dietary ingestion could modulate obesity, glucose metabolism, and the gut microbiota in an animal model of diet-induced obesity. Male C57BL/6J mice were fed a low-fat/low-sucrose diet (LF/LS), a HF/HS diet or a HF/HS diet containing 0.1% pot-pollen (HF/HS-PP) for 12 weeks. In HF/HS-fed mice, pot-pollen supplementation decreased fasting blood glucose and increased glucose-stimulated insulin secretion without modifying weight gain, body composition, glucose tolerance, and insulin sensitivity. Intake of pot-pollen resulted in changes of the gut microbiota, including a decrease in the abundance of the Rikenellaceae RC9 gut group and Lactobacillus, and an increase in the abundance of Romboutsia. Correlations between genus abundances and metabolic changes in response to supplementation indicated that the gut microbiota contributed to the positive effects of pot-pollen ingestion on fasting glucose. Pot-pollen supplementation-associated changes in the gut microbiota composition correlated with the lowering of fasting glucose levels without modulating weight gain.

Survival and activity of an indigenous iron-reducing microbial community from MX80 bentonite in high temperature / low water environments with relevance to a proposed method of nuclear waste disposal

MX80 bentonite clay has been selected as the buffer and backfill in a proposed method for long-term deep geological storage of nuclear waste. Extensive studies have been carried out on the geomechanical properties of the clay; however, it is not clear what effect microbes, specifically iron-reducing bacteria, will have on its ability to function as an affective barrier. Iron-reducing bacteria can reduce structural or external Fe(III) to Fe(II) and have been previously identified in the indigenous microbial community of MX80 bentonite. Experiments to assess bacterial survival at the high temperature and low water conditions likely to exist in the repository were carried out at different temperatures with the addition of steel to represent a nuclear waste canister. The resulting microbial enrichments were analysed, and mineralogical and geomechnical analysis was carried out on the clay. Microbial sequencing revealed that iron-reducing bacteria, and other indigenous species can survive these conditions in MX80 bentonite in either an active or dormant state. Microbial influenced mineralogical changes may lead to a loss of silica from the clay and reduction of Fe(III) to Fe(II). These changes could alter the ability of the clay to act as an effective barrier in nuclear waste disposal. Furthermore, evidence of reduced steel corrosion when microbes were present suggested that microbial activity may lead to either a protective coating on the steel or depletion of oxygen to slow corrosion. The production of such a layer would benefit nuclear waste disposal by inhibiting corrosion of a metal waste canister.

Lactobacillus reuteri CCFM8631 Alleviates Hypercholesterolaemia Caused by the Paigen Atherogenic Diet by Regulating the Gut Microbiota

Cardiovascular disease has one of the highest global incidences and mortality rates. Atherosclerosis is the main cause of cardiovascular disease, and hypercholesterolaemia and hyperlipidaemia are the main risk factors for the development of atherosclerosis. Decreasing serum cholesterol and triglyceride concentrations is considered to be an effective strategy to prevent atherosclerotic cardiovascular disease. Previous studies have shown that many diseases are related to gut microbiota dysbiosis. The positive regulation of the gut microbiota by probiotics may prevent or treat certain diseases. In this study, Lactobacillus reuteri CCFM8631 treatment was shown to decrease plasma total cholesterol (TC), low-density lipoprotein–cholesterol, aspartate transaminase, alanine transaminase and trimethylamine N-oxide concentrations, decrease liver TC and malondialdehyde concentrations and recover liver superoxide dismutase concentrations in mice fed a Paigen atherogenic diet. In addition, L. reuteri increased the faecal short-chain fatty acid content (acetate, propionate and butyrate), which was accompanied by an increase in the relative abundance of faecal Deferribacteres, Lachnospiraceae NK4A136 group, Lactobacillus and Dubosiella; a decrease in the relative abundance of Erysipelatoclostridium and Romboutsia and the activation of butanoate and vitamin B6 metabolism, leading to the alleviation of hypercholesterolaemia.

Enzymatic Preparation of Low-Molecular-Weight Laminaria japonica Polysaccharides and Evaluation of Its Effect on Modulating Intestinal Microbiota in High-Fat-Diet-Fed Mice

Recent studies have shown that seaweed polysaccharides can ameliorate high-fat-diet (HFD)-induced metabolic syndromes associated with the regulatory function of gut microbiota. However, kelp, a natural source of seaweed polysaccharides, is highly viscous, making it difficult to prepare dietary fiber by simple degradation. Therefore, we developed a novel method of preparing low-molecular-weight polysaccharides from Laminaria japonica by combining high-pressure pretreatment and composite enzymatic degradation and evaluated the obesity prevention activity of these polysaccharides. Seaweed L. japonica polysaccharides (SJP) were rapidly utilized by the human fecal microbiota in vitro, resulting in the generation of short-chain fatty acids (SCFAs), specifically acetate and propionate. The in vivo effects of SJP on the intestinal microbiota were also investigated using HFD-fed C57BL/6J mice. SJP reduced weight gain and fat deposition in HFD-fed mice and increased the concentration of total SCFAs, including acetate, propionate, and butyrate in the feces. SJP ameliorated HFD-induced gut microbiota dysbiosis, resulting in increased abundance of Faecalibaculum, Romboutsia, and Clostridium sensu stricto 1 and decreased abundance of Blautia and Lactobacillus. Further, SJP enhanced the abundance of Akkermansia muciniphila in mice provided with HFD and normal chow. Single-strain culture experiments also revealed that SJP promoted the growth of A. muciniphila. This study highlights the potential use of SJP, prepared using composite enzymatic degradation (cellulase and recombinant alginate lyase), in preventing obesity and restoring intestinal homeostasis in obese individuals.

Anti-aging potency correlates with metabolites from in vitro fermentation of edible fungal polysaccharides using human fecal intestinal microflora

Aging is a natural process in which the structural integrity of an organism declines over time.

Lactobacillus rhamnosus Strain LRH05 Intervention Ameliorated Body Weight Gain and Adipose Inflammation via Modulating the Gut Microbiota in High-Fat Diet-Induced Obese Mice

SCOPE

This study aims to investigate the underlying mechanism of a specific probiotic strain on suppression of adipogenesis and inflammatory response in white adipose tissue (WAT) of high-fat diet (HFD)-fed mice.

METHODS AND RESULTS

Eight strains are screened in vitro for candidates of potential probiotics. Lactobacillus rhamnosus LRH05 (LRH05) and Lactobacillus reuteri LR47 (LR47) are screened out with lower triglyceride expression in vitro. The mice are fed a control diet (CD), HFD, or HFD supplemented with a dose of LRH05 or LR47 at 10⁹ CFU per mouse per day for 10 weeks (n = 8), respectively. The results demonstrate that LRH05, but not LR47, significantly reduce body weight gain and the weight of WAT, as well as improve hepatic steatosis and glucose intolerance. LRH05 regulates the Mogat1, Igf-1, Mcp-1, and F4/80 mRNA expression and decreases macrophage infiltration in WAT. LRH05 shows an increase in butyric and propionic acid-producing bacteria, including Lachnoclostridium, Romboutsia, and Fusobacterium that is coincident with the increased fecal propionic acid and butyric acid levels.

CONCLUSION

LRH05 shows a strain-specific effect on ameliorating the pro-inflammatory process by reducing inflammatory macrophage infiltration and the expression of inflammation-related genes in mice. Thus, LRH05 can be considered a potential probiotic strain to prevent obesity.

The effects of fermented rye products on gut microbiota and their association with metabolic factors in Chinese adults - an explorative study

Rye is among the cereals with the highest content of dietary fibre. A high rye food intake has been associated with improved metabolic risk factors in some but not all observational and intervention studies. Whole-grain rye has also been suggested to affect the gut microbiota in individuals with metabolic syndrome. However, it is yet unclear to what extent effects on the gut microbiota mediate the beneficial metabolic responses of whole-grain rye intake. We hypothesized that a high intake of whole grain rye products containing fermented rye bran (FRB) vs. refined wheat based products (RW) could alter the gut microbiota and short-chain fatty acid (SCFA) composition towards a phenotype associated with beneficial metabolic effects in a population not used to such foods. For this purpose, we conducted a post hoc analysis of a 12-week randomized controlled trial in Chinese adults with Helicobacter pylori (HP) infection, with 53 participants consuming RW and 31 participants consuming FRB included in the analysis. Anthropometric measurements and fasting blood and fecal sample analyses as well as 13C-urea breath test were performed at baseline and after a 12-week intervention. At week 12, we observed a higher serum insulin concentration (P-value = 0.038) in the FRB group (n = 31) versus the RW group (n = 53), and this difference was corroborated with alterations in the genus-level relative abundances of the gut microbiota, represented by an increase in Romboutsia and a reduction in Bilophila in the FRB group (n = 22) versus the RW group (n = 46). Compared to the RW group (n = 53), fecal acetic acid concentration was significantly higher in the FRB group (n = 31) at week 12. We also found that fecal acetic and butyric acids positively, while isobutyric, isovaleric and 2-methylbutyric acids inversely, correlated with the gut Romboutsia level among all participants (n = 68) at week 12. We found positive correlations of fecal isobutyric, isovaleric and 2-methylbutyric acids with gut Bilophila (n = 68). In conclusion, our results suggest that the intake of high-fibre rye products could modify gut Romboutsia and Bilophila in a Chinese population with HP infection. These effects are paralleled with favorable modifications of the SCFA concentration and are associated with altered glycemic traits.

Characterization of the fecal microbiota of sows and their offspring from German commercial pig farms

Strategies to combat microbiota-associated health problems are of high interest in pig production. Successful intervention strategies with beneficial long-term effects are still missing. Most studies on pig microbiota have been conducted under standardized experimental conditions, but the situation in commercial farms differs dramatically. This study describes the fecal microbiota in German commercial pig farms under practical conditions. The study is part of the larger project "Optibiom" that aims to use bacterial composition and farm metadata to formulate tailor-made solutions for farm-specific health maintenance strategies. Special consideration is given to the sow-piglet relationship. Fecal samples from sows and their piglets were collected at two time points each in 20 different farms (sows ante- and postpartum and piglets before and after weaning). The extracted DNA was sequenced with Illumina 16S rDNA sequencing. For data analysis and visualization, differential abundance analyses, as well as hierarchical clustering and nonmetric multidimensional scaling (NMDS) were performed. A new "family unit" was implemented to compare farms based on the association between the microbiota in sows and their offspring. There are distinct changes in the microbial communities in sows before and after birth as well as in suckling and post-weaning piglets. The suckling pig microbiota is particularly different from all other groups and shows a lower bacterial diversity. While dominant genera in antepartum sows further displace the abundance of non-dominant genera postpartum, the opposite was true for piglets, where non-dominant bacteria in the suckling phase became dominant after weaning. The family unit for sows and their piglets led to separate cluster formation for some farms. The results indicate that the sow-piglet relationship is one driving force for the observed differences of the pig farms. The next step in the analysis will be the combination of metadata (feeding, housing and management practices) to find farm-specific differences that can be exploited to formulate a farm-specific health maintenance strategy.

Structural and quantitative alterations of gut microbiota in experimental small bowel obstruction

OBJECTIVE

To investigate structural and quantitative alterations of gut microbiota in an experimental model of small bowel obstruction.

METHOD

A rat model of small bowel obstruction was established by using a polyvinyl chloride ring surgically placed surrounding the terminal ileum. The alterations of gut microbiota were studied after intestinal obstruction. Intraluminal fecal samples proximal to the obstruction were collected at different time points (24, 48 and 72 hours after obstruction) and analyzed by 16s rDNA high-throughput sequencing technology and quantitative PCR (qPCR) for target bacterial groups. Furthermore, intestinal claudin-1 mRNA expression was examined by real-time polymerase chain reaction analysis, and serum sIgA, IFABP and TFF3 levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Small bowel obstruction led to significant bacterial overgrowth and profound alterations in gut microbiota composition and diversity. At the phylum level, the 16S rDNA sequences showed a marked decrease in the relative abundance of Firmicutes and increased abundance of Proteobacteria, Verrucomicrobia and Bacteroidetes. The qPCR analysis showed the absolute quantity of total bacteria increased significantly within 24 hours but did not change distinctly from 24 to 72 hours. Further indicators of intestinal mucosa damage and were observed as claudin-1 gene expression, sIgA and TFF3 levels decreased and IFABP level increased with prolonged obstruction.

CONCLUSION

Small bowel obstruction can cause significant structural and quantitative alterations of gut microbiota and induce disruption of gut mucosa barrier.

Dysbiosis in the Gut Microbiome in Streptozotocin-Induced Diabetes Rats and Follow-Up During Retinal Changes

Purpose

To analyze the gut bacterial microbiome of streptozotocin-induced diabetic rats and rats with retinal changes.

Methods

Induction of diabetes was confirmed by an increase in blood sugar (>150 mg/dL), and the progression of diabetes with retinal changes was assessed by histology and immunohistochemistry of retinal sections. Microbiomes were generated using fecal DNA, and the V3–V4 amplicons were sequenced and analyzed by QIIME and R.

Results

Dysbiosis in the gut microbiome of diabetic rats and diabetic rats with retinal changes was observed at the phylum and genus levels compared with the control rats. Heat-map analysis based on the differentially abundant genera indicated that the microbiomes of controls and diabetic rats separated into two distinct clusters. The majority of the microbiomes in diabetic rats with retinal changes also formed a distinct cluster from the control rats. β-diversity analysis separated the microbiome of control rats from the microbiome of diabetic rats and diabetic rats with retinal changes, but the microbiomes of diabetic rats and diabetic rats with retinal changes showed an overlap. Functional analysis indicated that the enhanced inflammation in diabetic rats showing retinal changes could be ascribed to a decrease in anti-inflammatory bacteria and an increase in pathogenic and proinflammatory bacteria.

Conclusions

This study showed that the gut bacterial microbiome in diabetic rats with retinal changes was different compared with control rats. The results could help develop novel therapeutics for diabetics and diabetic individuals with retinal changes.

The effect of microbial composition and proteomic on improvement of functional constipation by Chrysanthemum morifolium polysaccharide

In this paper, SD rat constipation model was established with loperamide hydrochloride to study the effect of Chrysanthemum morifolium polysaccharide on the improvement of functional constipation, and the mechanism of improving constipation was investigated with the proteomics and intestinal flora. The results showed that the HD group of C. morifolium polysaccharide could significantly increase the levels of water content of stool pellets, small intestine propulsion rate, gastrin (MTL), gastrin (GAS) and substance P (SP), decrease the level of growth inhibitor (SS) and improved gastrointestinal motility in rats. Gut microbial studies showed that C. morifolium polysaccharide could significantly increase species abundance and flora diversity and improve flora structure. The relative abundance of Lactobacillus and Romboutsia increased, while the relative abundance of Lachnospiraceae_NK4A136_group and Roseburia decreased compared with the MC group. Proteomics studies suggested that C. morifolium polysaccharides could reduce intestinal lesions, enhance intestinal homeostasis, increase amino acid uptake, promote intestinal motility and relieve constipation by regulating the expression of RAS, FABP1 and SLC1A5 proteins.

Fecal Methylmercury Correlates With Gut Microbiota Taxa in Pacific Walruses (Odobenus rosmarus divergens)

OBJECTIVES

Methylmercury metabolism was investigated in Pacific walruses (Odobenus rosmarus divergens) from St. Lawrence Island, Alaska, United States.

METHODS

Total mercury and methylmercury concentrations were measured in fecal samples and paired colon samples (n = 16 walruses). Gut microbiota composition and diversity were determined using 16S rRNA gene sequencing. Associations between fecal and colon mercury and the 24 most prevalent gut microbiota taxa were investigated using linear models.

RESULTS

In fecal samples, the median values for total mercury, methylmercury, and %methylmercury (of total mercury) were 200 ng/g, 4.7 ng/g, and 2.5%, respectively, while in colon samples, the median values for the same parameters were 28 ng/g, 7.8 ng/g, and 26%, respectively. In fecal samples, methylmercury was negatively correlated with one Bacteroides genus, while members of the Oscillospirales order were positively correlated with both methylmercury and %methylmercury (of total mercury). In colon samples, %methylmercury (of total mercury) was negatively correlated with members of two genera, Romboutsia and Paeniclostridium.

CONCLUSIONS

Median %methylmercury (of total mercury) was 10 times higher in the colon compared to the fecal samples, suggesting that methylmercury was able to pass through the colon into systemic circulation. Fecal total mercury and/or methylmercury concentrations in walruses were comparable to some human studies despite differences in seafood consumption rates, suggesting that walruses excreted less mercury. There are no members (at this time) of the Oscillospirales order which are known to contain the genes to methylate mercury, suggesting the source of methylmercury in the gut was from diet and not in vivo methylation.

Understanding the effects of intramuscular injection and feed withdrawal on Salmonella Typhimurium shedding and gut microbiota in pullets

Background

Gut microbiota plays a key role in health, immunity, digestion, and production in layers. Factors such as environment, diet, diseases, stress, and flock management significantly affect gut microbiota; however, it is not known how potential stressors such as intramuscular injections or feed withdrawal alter the composition of gut microbiota that result in increased the shedding level of foodborne pathogens. In the current study, the effects of intramuscular corticosterone injection and feed withdrawal were evaluated to understand their role in Salmonella Typhimurium shedding and changes in the composition of gut microbiota in layers.

Results

Salmonella shedding was observed for 8 weeks post-infection. There was a significant increase in Salmonella Typhimurium count after intramuscular injection and feed withdrawal. The Salmonella infected and the negative control groups showed significant differences in the abundance of different genera in gut microbiota at week 1 and up to week 7 post infection. The infected group showed a significant reduction in alpha diversity of gut microbiota. Firmicutes reduced significantly (P < 0.05) after intramuscular injection, while the feed withdrawal groups did not cause any significant changes in Proteobacteria-Firmicutes ratio. Furthermore, intramuscular injection resulted in a significant change in alpha diversity of gut microbiota.

Conclusions

Exposure of chicks to relatively low dose of Salmonella Typhimurium can lead to persistent shedding in pullets. The Salmonella Typhimurium infection disrupted the gut microbiota composition immediately after infection. The potential stress of intramuscular injection and feed withdrawal significantly increased the Salmonella Typhimurium count in faeces. The intramuscular injection also resulted in a significant alteration of the Proteobacteria-Firmicutes ratio, which could increase the risk of dysbiosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-021-00597-9.

Preventive Effects of Bacillus licheniformis on Heat Stroke in Rats by Sustaining Intestinal Barrier Function and Modulating Gut Microbiota

Heat stroke (HS) models in rats are associated with severe intestinal injury, which is often considered as the key event at the onset of HS. Probiotics can regulate the gut microbiota by inhibiting the colonization of harmful bacteria and promoting the proliferation of beneficial bacteria. Here, we investigated the preventive effects of a probiotic Bacillus licheniformis strain (BL, CMCC 63516) on HS rats as well as its effects on intestinal barrier function and gut microbiota. All rats were randomly divided into four groups: control (Con) + PBS (pre-administration with 1 ml PBS twice a day for 7 days, without HS induction), Con + BL group (pre-administration with 1 ml 1 × 10⁸ CFU/ml BL twice a day for 7 days, without HS induction), HS + PBS (PBS, with HS induction), and HS + BL (BL, with HS induction). Before the study, the BL strain was identified by genomic DNA analysis. Experimental HS was induced by placing rats in a hot and humid chamber for 60 min until meeting the diagnostic criterion of HS onset. Body weight, core body temperature, survival rate, biochemical markers, inflammatory cytokines, and histopathology were investigated to evaluate the preventive effects of BL on HS. D-Lactate, I-FABP, endotoxin, and tight-junction proteins were investigated, and the fluorescein isothiocyanate-dextran (FD-4) test administered, to assess the degree of intestinal injury and integrity. Gut microbiota of rats in each group were analyzed by 16S rRNA sequencing. The results showed that pre-administration with BL significantly attenuated hyperthermia, reduced HS-induced death, alleviated multiple-organ injury, and decreased the levels of serum inflammatory cytokines. Furthermore, BL sustained the intestinal barrier integrity of HS rats by alleviating intestinal injury and improving tight junctions. We also found that BL significantly increased the ratios of two probiotic bacteria, Lactobacillus and Lactococcus. In addition, Romboutsia, a candidate biomarker for HS diagnosis, was unexpectedly detected. In summary, BL pre-administration for 7 days has preventative effects on HS that may be mediated by sustaining intestinal barrier function and modulating gut microbiota.

Characterization of the Luminal and Mucosa-Associated Microbiome along the Gastrointestinal Tract: Results from Surgically Treated Preterm Infants and a Murine Model

Environmental factors, including nutritional habits or birth mode, are known key determinants for intestinal microbial composition. Investigations of the intestinal microbiome in different species in a multiplicity of studies during recent decades have revealed differential microbial patterns and quantities along the gastrointestinal (GI) tract. Characterization of the microbial pattern in various aspects is a prerequisite for nutritional interventions. In this 16S rRNA amplicon-based approach, we present a characterization of the mucosa-associated microbiome in comparison with the luminal community of four infants at the time of the closure of ileostomies and perform a systematic characterization of the corresponding luminal and mucosal microbiome from jejunal, ileal and colonic regions, as well as collected feces in mice. The most dominant taxa in infant-derived samples altered due to individual differences, and in the mucosa, Enterococcus, Clostridiumsensustricto1, Veillonella, Streptococcus and Staphylococcus were the most abundant. Two less abundant taxa differed significantly between the mucosa and lumen. In murine samples, relative abundances differed significantly, mainly between the intestinal regions. Significant differences between mouse mucosa- and lumen-derived samples could be found in the observed species with a trend to lower estimated diversity in mucosa-derived samples, as well as in the relative abundance of individual taxa. In this study, we examined the difference between the mucosal and luminal bacterial colonization of the gastrointestinal tract in a small sample cohort of preterm infants. Individual differences were characterized and statistical significance was reached in two taxa (Cupriavidus, Ralstonia). The corresponding study on the different murine intestinal regions along the GI tract showed differences all over the intestinal region.

Yeast Culture Improves Egg Quality and Reproductive Performance of Aged Breeder Layers by Regulating Gut Microbes

This study aimed to investigate the effects of dietary yeast culture (YC) supplementation on egg production, egg quality, reproductive performance, immune functions, antioxidant capacity, and intestinal microbial structure of aged hens. A total of 224 Hy-Line Brown layers (54 weeks old) were randomly assigned to two dietary treatments. The control group was fed a basal diet and the YC group was supplemented with YC at 2.0 g/kg of their diet. Each group had seven replicates with 16 hens each. The study was conducted over a period of 8 weeks. Results indicated that YC addition had no significant effect on laying performance. However, it significantly improved egg quality and hatching rate, enhanced ileum crude fat digestibility, increased the serum parameters of lysozyme (LZM) and total antioxidation capacity (T-AOC) (P < 0.05), and reduced serum aspartate aminotransferase (AST) levels (P < 0.05). Using 16S rRNA analysis, we found that addition of YC significantly altered ileum microbial composition. Linear discriminant analysis of effect size (LEfSe) showed significant enrichment of Bacilli and Lactobacilli in the YC group. PICRUSt analysis of the ileal microbiota found that glutathione metabolism, ubiquinone, and other terpenoid-quinone biosynthesis and lipopolysaccharide biosynthesis protein pathways were highly enriched in the YC group compared with the basal diet group. In summary, the addition of YC can improve egg quality, immune functions, antioxidant capacity, reproduction efficiency, and digestive absorption by increasing the abundance of Lactobacilli and Bacilli. Furthermore, it also improves the biosynthesis of lipopolysaccharide proteins, glutathione metabolism, and the synthesis of ubiquinone and other terpenoid-quinone metabolic pathways.

Taxonomic and Functional Characteristics of the Gill and Gastrointestinal Microbiota and Its Correlation with Intestinal Metabolites in NEW GIFT Strain of Farmed Adult Nile Tilapia (Oreochromis niloticus)

The gill and gastrointestinal tract are primary entry routes for pathogens. The symbiotic microbiota are essential to the health, nutrition and disease of fish. Though the intestinal microbiota of Nile tilapia (Oreochromis niloticus) has been extensively studied, information on the mucosa-associated microbiota of this species, especially the gill and gastrointestinal mucosa-associated microbiota, is lacking. This study aimed to characterize the gill and gastrointestinal mucosa- and digesta-associated microbiota, as well as the intestinal metabolite profiles in the New Genetically Improved Farmed Tilapia (NEW GIFT) strain of farmed adult Nile tilapia by high-throughput sequencing and gas chromatography/mass spectrometry metabolomics. The diversity, structure, composition, and predicted function of gastrointestinal microbiota were significantly different across gastrointestinal regions and sample types (Welch t-test; p < 0.05). By comparing the mucosa- and digesta-associated microbiota, linear discriminant analysis (LDA) effect size (LEfSe) analysis revealed that Pelomonas, Ralstoniapickettii, Comamonadaceae, and Staphylococcus were significantly enriched in the mucosa-associated microbiota, whereas many bacterial taxa were significantly enriched in the digesta-associated microbiota, including Chitinophagaceae, Cetobacterium, CandidatusCompetibacter, Methyloparacoccus, and chloroplast (LDA score > 3.5). Furthermore, Undibacterium, Escherichia-Shigella, Paeniclostridium, and Cetobacterium were dominant in the intestinal contents and mucosae, whereas Sphingomonasaquatilis and Roseomonasgilardii were commonly found in the gill and stomach mucosae. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) analysis revealed that the predictive function of digesta-associated microbiota significantly differed from that of mucosa-associated microbiota (R = 0.8152, p = 0.0001). In addition, our results showed a significant interdependence between specific intestinal microbes and metabolites. Notably, the relative abundance values of several potentially beneficial microbes, including Undibacterium, Crenothrix, and Cetobacterium, were positively correlated with most intestinal metabolites, whereas the relative abundance values of some potential opportunistic pathogens, including Acinetobacter, Mycobacterium, Escherichia-Shigella, Paeniclostridium, Aeromonas, and Clostridiumsensustricto 1, were negatively correlated with most intestinal metabolites. This study revealed the characteristics of gill and gastrointestinal mucosa-associated and digesta-associated microbiota of farmed Nile tilapia and identified a close correlation between intestinal microbes and metabolites. The results serve as a basis for the effective application of targeted probiotics or prebiotics in the diet to regulate the nutrition and health of farmed tilapia.

The effect of acute moderate-intensity exercise on the serum and fecal metabolomes and the gut microbiota of cross-country endurance athletes

Physical exercise can produce changes in the microbiota, conferring health benefits through mechanisms that are not fully understood. We sought to determine the changes driven by exercise on the gut microbiota and on the serum and fecal metabolome using 16S rRNA gene analysis and untargeted metabolomics. A total of 85 serum and 12 fecal metabolites and six bacterial taxa (Romboutsia, Escherichia coli TOP498, Ruminococcaceae UCG-005, Blautia, Ruminiclostridium 9 and Clostridium phoceensis) were modified following a controlled acute exercise session. Among the bacterial taxa, Ruminiclostridium 9 was the most influenced by fecal and serum metabolites, as revealed by linear multivariate regression analysis. Exercise significantly increased the fecal ammonia content. Functional analysis revealed that alanine, aspartate and glutamate metabolism and the arginine and aminoacyl-tRNA biosynthesis pathways were the most relevant modified pathways in serum, whereas the phenylalanine, tyrosine and tryptophan biosynthesis pathway was the most relevant pathway modified in feces. Correlation analysis between fecal and serum metabolites suggested an exchange of metabolites between both compartments. Thus, the performance of a single exercise bout in cross-country non-professional athletes produces significant changes in the microbiota and in the serum and fecal metabolome, which may have health implications.

Linkage between the intestinal microbiota and residual feed intake in broiler chickens

Background

Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on feed efficiency of livestock animals. However, the intestinal microbes that are critically involved in feed efficiency remain elusive.

Methods

To identify intestinal bacteria associated with residual feed intake (RFI) in chickens, male Cobb broiler chicks were individually housed from day 14 to day 35. Individual RFI values were calculated for 56 chickens. Luminal contents were collected from the ileum, cecum, and cloaca of each animal on day 35. Bacterial DNA was isolated and subjected to 16S rRNA gene sequencing. Intestinal microbiota was classified to the feature level using Deblur and QIIME 2. High and low RFI groups were formed by selecting 15 and 17 chickens with the most extreme RFI values for subsequent LEfSe comparison of the difference in the microbiota. Spearman correlation analysis was further performed to identify correlations between the intestinal microbiota composition and RFI.

Results

No significant difference in evenness, richness, and overall diversity of the microbiota in the ileum, cecum, or cloaca was observed between high and low RFI chickens. However, LEfSe analysis revealed a number of bacterial features being differentially enriched in either high or low RFI chickens. Spearman correlation analysis further identified many differentially enriched bacterial features to be significantly correlated with RFI (P < 0.05). Importantly, not all short-chain fatty acid (SCFA) producers showed a positive association with RFI. While two novel members of Oscillibacter and Butyricicoccus were more abundant in low-RFI, high-efficiency chickens, several other SCFA producers such as Subdoligranulum variabile and two related Peptostreptococcaceae members were negatively associated with feed efficiency. Moreover, a few closely-related Lachnospiraceae family members showed a positive correlation with feed efficiency, while others of the same family displayed an opposite relationship.

Conclusions

Our results highlight the complexity of the intestinal microbiota and a need to differentiate the bacteria to the species, subspecies, and even strain levels in order to reveal their true association with feed efficiency. Identification of RFI-associated bacteria provides important leads to manipulate the intestinal microbiota for improving production efficiency, profitability, and sustainability of poultry production.

Male castration increases adiposity via small intestinal microbial alterations

Castration of young males is widely used in the cattle industry to improve meat quality, but the mechanism linking hypogonadism and host metabolism is not clear. Here, we use metataxonomic and metabolomic approaches to evaluate the intestinal microbiota and host metabolism in male, castrated male (CtM), and female cattle. After pubescence, the CtM cattle harbor distinct ileal microbiota dominated by the family Peptostreptococcaceae and exhibit distinct serum and muscle amino acid profiles (i.e., highly abundant branched-chain amino acids), with increased extra- and intramuscular fat storage. We also evaluate the causative factor(s) that underpin the alteration of the intestinal microbiota and host metabolic phenotype in response to hypogonadism. Castration of male mice phenocopies both the intestinal microbial alterations and obese-prone metabolism observed in cattle. Antibiotic treatment and fecal microbiota transplantation experiments in a mouse model confirm that the intestinal microbial alterations associated with hypogonadism are a key contributor to the obese phenotype in the CtM animals. Collectively, targeting the gut microbiota is a potential therapeutic strategy for the treatment of both hypogonadism and obesity.

Characterization of the Intestinal Microbiota of Broiler Breeders With Different Egg Laying Rate

The gastrointestinal microbiota plays a pivotal role in maintaining animal health, immunity and reproductive performances. However, literature about the relationship between microbiota and reproductive performance is limited. The aim of the present study was to determine differences in the intestinal microbiota of broiler breeders with different egg laying rate. A total of 200 AA+ parent broiler breeders (41-week-old) were separated into two groups according to their different egg laying rate [average egg laying rate group (AR: 78.57 ± 0.20%) and high egg laying rate group (HR: 90.79 ± 0.43%). Feed conversion ratio (FCR), ovary cell apoptosis rate (ApoCR) and relative abdominal fat weight were lower (p = 0.01), while the hatchability rate of qualified egg was higher (p = 0.04) in HR group than that in AR group. Phascolarctobacterium abundance were lower (p = 0.012) in ileum of HR birds. Romboutsia (genus) in ileum was negatively related to the feed efficiency (r = -0.58, p < 0.05), Firmicutes (phylum) and Lactobacillus (genus) abundances in cecum were positively related to the egg laying rate (ELR) (r = 0.35 and 0.48, p < 0.05), feed efficiency (r = 0.42 and 0.43, p < 0.05), while Spirochaetes (phylum) and Sphaerochaeta (genus) abundances in cecum were negatively related to the ELR (r = -0.43 and -0.70, p < 0.05), feed efficiency (r = 0.54 and 0.48, p < 0.05), and positively related to ApoCR (r = 0.46 and 0.47, p < 0.05). Our results suggested that microbiota, such as Firmicutes (phylum) and Lactobacillus (genus) have positive relationship, while Spirochaetes (phylum) and Romboutsia (genus) abundances exert negative relationship with broiler breeders' reproductive performances.