Your browser does not allow saving data (e.g. private mode): bookmarks will be lost when the tab closes.
Search PubMed
Keywords, author, journal, years — results from PubMed, abstracts with Russian translation, bookmarks in your browser.
Found: 3 214
Page 239 of 322-
Transglycosylated starch accelerated intestinal transit and enhanced bacterial fermentation in the large intestine using a pig model.
Resistant starch can alter the intestinal nutrient availability and bulk of digesta, thereby modulating the substrate available for microbial metabolic activity along the gastrointestinal tract. This study elucidated the effect of transglycosylated starch (TGS) on the retention of digesta in the upper digestive tract, ileal flow and hindgut disappearance of nutrients, and subsequent bacterial profiles in pigs. Fourteen ileal-cannulated growing pigs were fed either the TGS or control (CON) diet in a complete crossover design. Each period consisted of a 10-d adaptation to the diets, followed by 3-d collection of faeces and ileal digesta. Consumption of TGS decreased the retention of digesta in the stomach and small intestine, and increased ileal DM, starch, Ca and P flow, leading to enhanced starch fermentation in the hindgut compared with CON-fed pigs. TGS increased ileal and faecal total SCFA, especially ileal and faecal acetate and faecal butyrate. Gastric retention time positively correlated to Klebsiella, which benefitted together with Selenomonas, Lactobacillus, Mitsuokella and Coriobacteriaceae from TGS feeding and ileal starch flow. Similar relationships existed in faeces with Coriobacteriaceae, Veillonellaceae and Megasphaera benefitting most, either directly or indirectly via cross-feeding, from TGS residuals in faeces. TGS, in turn, depressed genera within Ruminococcaceae, Clostridiales and Christensenellaceae compared with the CON diet. The present results demonstrated distinct ileal and faecal bacterial community and metabolite profiles in CON- and TGS-fed pigs, which were modulated by the type of starch, intestinal substrate flow and retention of digesta in the upper digestive tract.
-
Effect of 2-hydroxy-4-(methylthio) butanoate (HMTBa) supplementation on rumen bacterial populations in dairy cows when exposed to diets with risk for milk fat depression.
Diet-induced milk fat depression (MFD) is a condition marked by a reduction in milk fat yield experimentally achieved by increasing dietary unsaturated fatty acids and fermentable carbohydrates. 2-Hydroxy-4-(methylthio) butanoate (HMTBa) is a methionine analog observed to reduce diet-induced MFD in dairy cows. We hypothesize that the reduction in diet-induced MFD by HMTBa is due to changes in the rumen microbiota. To test this, 22 high-producing cannulated Holstein dairy cows were placed into 2 groups using a randomized block design and assigned to either control or HMTBa supplementation (0.1% of diet dry matter). All cows were then exposed to 3 different diets with a low risk (32% neutral detergent fiber, no added oil; fed d 1 to 7), a moderate risk (29% neutral detergent fiber and 0.75% soybean oil; fed d 8 to 24), or a high risk (29% neutral detergent fiber and 1.5% soybean oil; fed d 25 to 28) for diet-induced MFD. Rumen samples were collected on d 0, 14, 24, and 28, extracted for DNA, PCR-amplified for the V1-V2 region of the 16S rRNA gene, sequenced on an Illumina MiSeq (Illumina, San Diego, CA), and subjected to bacterial diversity analysis using the QIIME pipeline. The α diversity estimates (species richness and Shannon diversity) were decreased in the control group compared with the HMTBa group. Bacterial community composition also differed between control and HMTBa groups based on both weighted UniFrac (relative abundance of commonly detected bacteria) and unweighted UniFrac (presence/absence) distances. Within the HMTBa group, no differences were observed in bacterial community composition between d 0 and d 14, 24, and 28; however, in the control group, d 0 samples were different from d 14, 24, and 28. Certain bacterial genera including Dialister, Megasphaera, Lachnospira, and Sharpea were increased in the control group compared with the HMTBa group. Interestingly, these genera were positively correlated with milk fat trans-10,cis-12 conjugated linoleic acid and trans-10 C18:1, fatty acid isomers associated with biohydrogenation-induced MFD. It can be concluded that diet-induced MFD is accompanied by significant alterations in the rumen bacterial community and that HMTBa supplementation reduces these microbial perturbations.
-
Effect of synbiotic and probiotic supplementation on serum brain-derived neurotrophic factor level, depression and anxiety symptoms in hemodialysis patients: a randomized, double-blinded, clinical trial.
BACKGROUND: The aim of this study was to investigate the effects of probiotic and synbiotic supplementation on the depression and anxiety symptoms and serum brain-derived neurotrophic factor (BDNF) level. METHODS: Seventy-five HD patients were randomly assigned to receive the synbiotic (15 g of prebiotics, 5 g of probiotic containing Lactobacillus acidophilus T16, Bifidobacterium bifidum BIA-6, Bifidobacterium lactis BIA-7, and Bifidobacterium longum BIA-8 (2.7 × 107 CFU/g each)) or probiotics (5 g probiotics as in synbiotic group with 15 g of maltodextrin as placebo) or placebo (20 g of maltodextrin) for 12 weeks. Serum BDNF was measured by ELISA kit. Hospital Anxiety and Depression Scale (HADS) was used to assess symptoms of depression (HADS-DEP) and anxiety (HADS-ANX). RESULTS: From baseline to 12 weeks, synbiotic supplementation resulted in a significant decrease in HADS-DEP score in a subgroup of patients with depressive symptom (HADS-DEP ≥ 8) compared to the placebo and probiotic supplementation (p = .001, p = .002, respectively) and in all patients compared to the placebo (p = .004). There was no significant difference among the groups in terms of HADS-ANX scores. However, the HADS-ANX scores decreased significantly in the synbiotic group compared to the baseline in all patients (p = .047) and also patients with depressive symptom (p = .03). In addition, in a subgroup of HD patients with depressive symptom, the serum BDNF increased significantly in the synbiotic group when compared to the placebo (p < .001) and probiotic group (p = .011). CONCLUSION: Overall, 12 weeks of synbiotic supplementation resulted in greater improvement in depression symptoms and serum BDNF level compared to the probiotic supplementation in HD patients especially in the subgroup of patients with depression symptoms.
-
Effect of stoned olive pomace on rumen microbial communities and polyunsaturated fatty acid biohydrogenation: an in vitro study.
BACKGROUND: Stoned olive pomace (SOP), which represents approximately 50% of the conversion process of olives to olive oil, is largely not utilised and creates costs for its disposal and has negative environmental impacts. In vitro trial experiments were employed to study the effect of feeds integrated with this bio-waste, which is rich in polyphenols, on rumen biohydrogenation, using sheep rumen liquor as inoculum. RESULTS: Fatty acid (FA) analysis and a polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) approach aimed at characterising the microbial community indicated that including SOP in feeds at the level of 50 g/kg and 90 g/kg induced changes in the FA profile and microbial populations. The simultaneous decrease of Butyrivibrio proteoclasticus and accumulation of vaccenic acid was observed. A depression in the populations of Neisseria weaveri, Ruminobacter amylophilus and other unclassified bacteria related to members of the Lachnospiraceae and Pasteurellaceae families was detected, suggesting that these microbial groups may be involved in rumen biohydrogenation. CONCLUSIONS: Supplementation of feeds with SOP alters the rumen bacterial community, including bacteria responsible for the hydrogenation of vaccenic acid to stearic acid, thereby modifying the FA profile of the rumen liquor. Hence, a use of SOP aimed to produce meat or dairy products enriched in functional lipids can be hypothesised.
-
Altered colonic function and microbiota profile in a mouse model of chronic depression.
BACKGROUND: Depression often coexists with the irritable bowel syndrome (IBS) which is characterized by alterations in gut function. There is emerging evidence that the microbial composition (microbiota) of the gut is altered in IBS, but the basis for this is poorly understood. The aim of this study was to determine whether the induction of chronic depression results in changes in the colonic function and in its microbial community, and to explore underlying mechanisms. METHODS: Bilateral olfactory bulbectomy (OBx) was used to induce depression-like behavior in mice. Colonic function was assessed by measuring muscle contractility, pellet excretion, c-fos activity, and serotonin levels. Microbiota profiles were obtained using denaturing gradient gel electrophoresis (DGGE). The hypothalamic-pituitary axis (HPA) was assessed by the hypothalamic expression of corticotropin-releasing hormone (CRH). In separate studies, mice without OBx received CRH via intracerebroventricular (ICV) infusion for 4 weeks prior to assessing colonic function and microbiota profiles. KEY RESULTS: Olfactory bulbectomy mice demonstrated chronic depression- and anxiety-like behaviors associated with elevated central CRH expression and increases in c-Fos activity, serotonin levels, and motility in the colon. These changes were accompanied by an altered intestinal microbial profile. Central CRH administration produced similar changes in behavior and motility and altered the microbiota profile in the colon. CONCLUSIONS & INFERENCES: The induction of chronic depression alters motor activity and the microbial profile in the colon likely via activation of the HPA. These findings provide a basis for linking the behavioral and gastrointestinal manifestations of IBS.
-
Molecular Mechanisms of Reelin in the Enteric Nervous System and the Microbiota-Gut-Brain Axis: Implications for Depression and Antidepressant Therapy.
Current pharmacological treatments for depression fail to produce adequate remission in a significant proportion of patients. Increasingly, other systems, such as the microbiome-gut-brain axis, are being looked at as putative novel avenues for depression treatment. Dysbiosis and dysregulation along this axis are highly comorbid with the severity of depression symptoms. The endogenous extracellular matrix protein reelin is present in all intestinal layers as well as in myenteric and submucosal ganglia, and its receptors are also present in the gut. Reelin secretion from subepithelial myofibroblasts regulates cellular migration along the crypt-villus axis in the small intestine and colon. Reelin brain expression is downregulated in mood and psychotic disorders, and reelin injections have fast antidepressant-like effects in animal models of depression. This review seeks to discuss the roles of reelin in the gastrointestinal system and propose a putative role for reelin actions in the microbiota-gut-brain axis in the pathogenesis and treatment of depression, primarily reflecting on alterations in gut epithelial cell renewal and in the clustering of serotonin transporters.
-
Microbiota-Gut-Brain Axis in Psychiatry: Focus on Depressive Disorders.
PURPOSE OF REVIEW: Gut microbiota contribute to several physiological processes in the host. The composition of the gut microbiome is associated with different neurological and neurodevelopmental diseases. In psychiatric disease, stress may be a major factor leading to gut microbiota alterations. Depressive disorders are the most prevalent mental health issues worldwide and patients often report gastrointestinal symptoms. Accordingly, evidence of gut microbial alterations in depressive disorders has been growing. Here we review current literature revealing links between the gut microbiome and brain function in the context of depression. RECENT FINDINGS: The gut-brain axis could impact the behavioral manifestation of depression and the underlying neuropathology via multiple routes: the HPA axis, immune function, the enteric nervous system, and the vagus nerve. Furthermore, we explore possible therapeutic interventions including fecal microbiota transplant or probiotic supplementation in alleviating depressive symptoms. SUMMARY: Understanding the mechanisms by which bidirectional communication along the gut-brain axis can be dysregulated in patients with depression could lead to the development of personalized, microbiome-targeted therapies for the treatment of this disorder.
-
Short-Chain Fatty Acids Ameliorate Depressive-like Behaviors of High Fructose-Fed Mice by Rescuing Hippocampal Neurogenesis Decline and Blood-Brain Barrier Damage.
Excessive fructose intake is associated with the increased risk of mental illness, such as depression, but the underlying mechanisms are poorly understood. Our previous study found that high fructose diet (FruD)-fed mice exhibited neuroinflammation, hippocampal neurogenesis decline and blood-brain barrier (BBB) damage, accompanied by the reduction of gut microbiome-derived short-chain fatty acids (SCFAs). Here, we found that chronic stress aggravated these pathological changes and promoted the development of depressive-like behaviors in FruD mice. In detail, the decreased number of newborn neurons, mature neurons and neural stem cells (NSCs) in the hippocampus of FruD mice was worsened by chronic stress. Furthermore, chronic stress exacerbated the damage of BBB integrity with the decreased expression of zonula occludens-1 (ZO-1), claudin-5 and occludin in brain vasculature, overactivated microglia and increased neuroinflammation in FruD mice. These results suggest that high fructose intake combined with chronic stress leads to cumulative negative effects that promote the development of depressive-like behaviors in mice. Of note, SCFAs could rescue hippocampal neurogenesis decline, improve BBB damage and suppress microglia activation and neuroinflammation, thereby ameliorate depressive-like behaviors of FruD mice exposed to chronic stress. These results could be used to develop dietary interventions to prevent depression.
-
Effect of Ruanjian Xiaoying Granules on Hashimoto Rats with Depression of Liver and Deficiency of Spleen and Effect on Intestinal Microflora.
In order to investigate the effect of Ruanjian Xiaoying Granule, experiments were conducted on the intestinal flora of rats with liver depression and spleen deficiency. 48 SPF grade rats are used as the object, and 12 rats are randomly selected as the normal control group. The Hashimoto rat model of liver depression and spleen deficiency type by drug intervention is constructed by the remaining rats. They are randomly divided into three groups: the model group, the traditional Chinese medicine group, and the Jinshuibao group. The normal group and model group are given 2 ml of distilled water twice a day, and the traditional Chinese medicine group is given the Ruanjian Xiaoying granule group (12.96 g/kg/day) twice a day. The Jinshuibao capsule is dissolved in water and given orally at a dose of 0.45 g/kg/day twice a day. After 12 weeks of intervention, the effect is evaluated, and the levels of serum TGAb, TPOAb, and bacterial diversity are compared. Experimental results show that Ruanjian Xiaoying granules can promote the regulation of flora levels in Hashimoto rats with liver depression and spleen deficiency.
-
Relationship between depression and oral microbiome diversity: analysis of NHANES data (2009-2012).
BACKGROUND: While the association between the gut microbiome and depression is well studied, the association between the oral microbiome and depression is less well characterized. METHODS: This cross-sectional study analyzed the association between depression and diversity of oral microbiome using data from the 2009-2012 National Health and Nutrition Examination Survey (NHANES). The gene sequencing of 16S ribosomal RNA was adopted for the profiling of oral microbiome. Alpha diversity, quantified by the observed number of amplicon sequence variants (ASVs), and beta diversity, assessed using Bray-Curtis dissimilarity, were evaluated to represent oral microbiome diversity. Depressive symptoms were measured by the Patient Health Questionnaire-9 (PHQ-9) scale, with alpha diversity as the primary predictor. Weighted logistic regression was employed to examine the relationship between depression and microbial alpha diversity. Threshold effect analysis was performed to explore potential nonlinear relationships between the observed ASVs and depression. Subgroup analysis indicated that smoke, excessive alcohol consumption, and oral treatment influenced the association between oral microbiology and depression, with interaction effects observed across gender and racial groups. Beta diversity differences were evaluated using Bray-Curtis dissimilarity and visualized via non-metric multidimensional scaling (NMDS). RESULTS: A total of 15,018 participants were included, with an average age of 42.25 ± 15.2 years. In the fully adjusted model, the alpha diversity of oral microbiome was significantly negatively correlated with depression (OR = -0.51, 95% CI: -0.79--0.23, P = 0.003). Threshold analysis also revealed a nonlinear association in this relationship, with a significant inflection point as Log10ASVs of 2.32. Furthermore, beta diversity of the oral microbiome differed significantly between the normal and depression groups (p = 0.001). Sensitivity analyses showed that the relationship between depression and oral microbial diversity observed in this research was particularly pronounced among non-Hispanic Whites (OR = 0.16, 95% CI: 0.07-0.35) and men (OR = 0.14, 95% CI: 0.06-0.30). Additionally, significant differences in oral microbiome beta diversity were observed between the normal and depression groups (p = 0.001). CONCLUSIONS: The findings suggest that the diversity of oral microbiome is negatively correlated with depressive symptoms. Hence, oral dysbiosis may serve as a therapeutic target or biomarker of depression. However, the underlying mechanisms require further investigation.