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 246 of 322-
Processing barley grain with lactic acid and tannic acid ameliorates rumen microbial fermentation and degradation of dietary fibre in vitro.
BACKGROUND: Cereal grains are important ingredients of ruminant diets, but their rapid degradation seriously impairs rumen fermentation and the host's health. The goal of this study was to evaluate whether processing of barley grain with 1 or 5% lactic acid (LA) and 1 or 5% tannic acid (TA), without or with an additional heat treatment (1% LAH or 1% TAH), may affect microbial ruminal abundance, fermentation profile, and nutrient degradation in vitro. RESULTS: Processing with LA lowered (P < 0.05) the concentration of short-chain fatty acids (SCFAs), proportions of branched-chain SCFA, and the acetate-to-propionate ratio. Treatment with 1% TAH and 1% LAH lowered (P < 0.05) gene copy numbers of total protozoa, rumen lipopolysaccharide, and degradation of crude protein, and tended (P = 0.08) to lower the proportion of the genus Prevotella. Treatment of barley grain with 1% LA or 1% LAH stimulated Clostridium cluster XIV. Degradation of fibre was enhanced (P < 0.05) by all LA and TA treatments. CONCLUSION: Chemical and heat treatment of barley grain modulated the ruminal fermentation profile and enhanced fibre degradation; however, processing of grain with LA seems to be superior because this effect was not associated with a concomitant depression in ruminal degradation of organic matter.
-
Increasing linseed supply in dairy cow diets based on hay or corn silage: Effect on enteric methane emission, rumen microbial fermentation, and digestion.
We investigated the effects of increasing extruded linseed supply in diets based on hay (H; experiment 1) or corn silage (CS; experiment 2) on enteric methane (CH4) emission, rumen microbial and fermentation parameters, and rumen and total-tract digestibility. In each experiment, 4 lactating Holstein cows fitted with cannulas at the rumen and proximal duodenum were used in a 4×4 Latin square design (28-d periods). Cows were fed ad libitum a diet [50:50 and 60:40 forage:concentrate on a dry matter (DM) basis for experiments 1 and 2, respectively] without supplementation (H0, CS0) or supplemented with extruded linseed at 5% (H5, CS5), 10% (H10, CS10), and 15% (H15, CS15) of dietary DM (i.e., 1.8, 3.6 and 5.4% total fatty acids added, respectively). All measurements were carried out during the last 8 d of each period. Linseed supply linearly decreased daily CH4 emission in cows fed H diets (from 486 to 289g/d for H0 to H15, on average) and CS diets (from 354 to 207g/d for CS0 to CS15, on average). The average decrease in CH4 per kilogram of DM intake was, respectively, -7, -15, and -38% for H5, H10, H15 compared with the H0 diet, and -4, -8, and -34% for CS5, CS10, and CS15 compared with the CS0 diet. The same dose-response effect was observed on CH4 emission in percent of gross energy intake, per kilogram of nutrient digested, and per kilogram of 4% fat- and 3.3% protein-corrected milk (FPCM) in both experiments. Changes in the composition of rumen volatile fatty acids in response to increasing linseed supply resulted in a moderate or marked linear decrease in acetate:propionate ratio for H or CS diets, respectively. The depressive effect of linseed on total protozoa concentration was linear for H diets (-15 to -40%, on average, for H5 to H15 compared with H0) and quadratic for CS diets (-17 to -83%, on average, for CS5 to CS15 compared with CS0). Concentration of methanogens was similar among H or CS diets. The energetic benefits from the decreased CH4 emission with linseed supply in diets based on hay or corn silage did not improve digestibility or milk yield. Milk efficiency (kg of FPCM/kg of DM intake) was improved with linseed supply up to H10 in H diets and was unchanged in CS diets. Lower CH4 enteric emission from dairy cows fed linseed helps limit the environmental footprint of ruminant livestock.
-
Psychobiotic Effects of Postbiotics in Depression, Psychosis and Mania.
BACKGROUND: The gut microbiota significantly influences mental health through the gut-brain axis, modulating mood, cognition, and emotional regulation. While probiotics and prebiotics have been widely studied for their psychobiotic effects, postbiotics-metabolic byproducts of probiotics-represent an underexplored area with potential therapeutic applications. Understanding the role of postbiotics in mental health disorders, such as depression, psychosis, and mania, could lead to novel treatment strategies. This review examines the psychobiotic potential of postbiotics and their mechanisms of action. METHODS: A systematic literature review was conducted to evaluate the effects of postbiotics on mental health conditions. We searched PubMed, Medline, EMBASE, and the Cochrane Library for English-language articles published between January 1, 2015, and January 1, 2025, using keywords such as "postbiotic," "paraprobiotic," "depression," "anxiety," and "psychosis." A manual search supplemented the electronic search to ensure comprehensive coverage. Studies focusing on postbiotic effects on mood regulation, neuroinflammation, and neurotransmitter modulation were included. RESULTS: Postbiotics demonstrate promising psychobiotic effects in depression, psychosis, and mania. They modulate neurotransmitter levels, including serotonin and gamma-aminobutyric acid (GABA), and reduce neuroinflammation, contributing to improved mood and cognitive function. Additionally, postbiotics influence the hypothalamic-pituitary-adrenal (HPA) axis, enhancing stress response and emotional regulation. These findings suggest that postbiotics may serve as effective therapeutic agents for mental health disorders. CONCLUSION: Postbiotics offer significant potential as novel interventions for mental health conditions, with mechanisms involving neurotransmitter modulation and neuroinflammation reduction. Further empirical research is needed to elucidate their clinical applications and optimize therapeutic protocols. This review highlights the importance of postbiotics in advancing innovative strategies to improve mental health outcomes and well-being.
-
A prospective analysis of dietary fiber intake and mental health quality of life in the Iowa Women's Health Study.
OBJECTIVE: Recent studies have reported associations between dietary intake and mental health. Dietary fiber is one nutrient that may modulate mental health, specifically depression risk, through the gut microbiome. We prospectively examined the association between dietary fiber intake and mental health-related quality of life (QOL) scores, a proxy for depressive symptoms, in a cohort of 14,129 post-menopausal women in the Iowa Women's Health Study. METHODS: Dietary intake was assessed at baseline [1986] using a 127-item food frequency questionnaire. Mental health-related QOL scores were assessed at the follow-up questionnaire [2004] using the Mental Health (MH) component and Mental Health Composite (MCS) scales derived from the SF-36 Health Survey. The association between dietary fiber intake and mean QOL scores was examined using linear regression, with adjustment for age, alcohol intake, energy intake, waist-to-hip ratio, physical activity, smoking status, and education. RESULTS: The median dietary fiber intake was 19.0 g/day, ranging from 1.1 to 89.4 g/day. Multivariable-adjusted mean MH scores were higher among those with higher fiber intake (P for trend = 0.02). For MCS score, the association with fiber intake observed in a model adjusted for age and energy intake became insignificant after multivariable adjustment. CONCLUSIONS: Our study is one of the first prospective analyses of the association between higher dietary fiber intake and increased MH QOL scores later in life. Given a plausible biological mechanism underlying the association between fiber intake and mental health, additional studies are warranted.
-
Increased Ileal Immunoglobulin A Production and Immunoglobulin A-Coated Bacteria in Diarrhea-Predominant Irritable Bowel Syndrome.
OBJECTIVES: Immune activation and intestinal microbial dysbiosis could induce diarrhea-predominant irritable bowel syndrome (IBS-D). We examined the roles of ileal immunoglobulin A (IgA) and IgA-coated bacteria in IBS-D pathogenesis. METHODS: Peripheral blood, fecal samples, and ileal and cecal biopsies were collected from 32 healthy volunteers and 44 patients with IBS-D. Quantitative reverse transcriptase polymerase chain reaction was used to assess differential gene expression. IgA levels in the blood and fecal samples were quantified by an enzyme-linked immunosorbent assay. IgA cells were assessed by immunofluorescence imaging. Flow-cytometry-based IgA bacterial cell sorting and 16S rRNA gene sequencing (IgA-SEQ) was used to isolate and identify fecal IgA bacteria. RESULTS: Fecal IgA, particularly IgA1, was upregulated in patients with IBS-D. IgA class switch and B cell-activating factor-receptor were increased in the terminal ileum of patients. The intestinal microbiota composition was altered in patients compared with that in controls. IgA-SEQ showed that the proportion of fecal IgA-coated bacteria was increased significantly in patients with IBS-D. IgA bacteria in patients with IBS-D showed higher abundances of Escherichia-Shigella, Granulicatella, and Haemophilus compared with healthy controls and IgA bacteria in patients with IBS-D. The Escherichia-Shigella IgA coating index was positively correlated with anxiety and depression. The Escherichia-Shigella relative abundance, luminal IgA activity, and some altered IgA-coated bacteria were positively associated with the clinical manifestations of IBS-D. DISCUSSION: Microbial dysbiosis may promote the terminal ileal mucosa to produce higher levels of IgA, increasing the proportion of IgA-coated bacteria by activating IgA class switching, which might regulate local inflammation and clinical manifestations in IBS-D. IgA may mediate the effects of microbial dysbiosis on the pathogenesis of IBS-D.
-
Gut Microbiome and Depression: How Microbes Affect the Way We Think.
The gut microbiome serves an important role in the human body. Reportedly, one of the benefits of these microflora is on mental health. Once established, food and other dietary sources that enhance quality microbiome content in our gastrointestinal system will be a significant consideration in individuals' day to day lives. This literature review conducted a PubMed search for studies about the gut microbiome and its relation to depression. In using several Medical Subject Heading (MeSH) keywords, relevant literature was selected. A total of 26 articles were selected after applying the inclusion and exclusion criteria, and after checking the articles' accessibility. This literature would like to establish the role of the gut microbiome in depression. This study's findings showed that there is a strong association of microbiome function to mental well-being.
-
Serum homocysteine showed potential association with cognition and abnormal gut microbiome in major depressive disorder.
BACKGROUND: Cognitive impairment is one of the common clinical manifestations of depression, causing negative distress to patients. Elevated homocysteine (Hcy) concentrations and gut microbiome dysfunction may be observed in patients with depression. AIM: To investigate the relationship between Hcy, microbiome, and cognition in depressive patients. METHODS: We recruited 67 patients with major depressive disorder (MDD) (MDD group) and 94 healthy controls (HCs) individuals (HCs group). Serum Hcy levels were determined using the enzyme circulation method. 16s rRNA sequencing was used to classify and identify the fecal bacteria. 17 Hamilton depression rating scale and MATRICS consensus cognitive battery were used to evaluate mood states and cognition in patients with MDD. Correlation analysis was performed to explore the correlation between fecal flora, Hcy, and depressive cognitive function. RESULTS: Elevated serum levels of Hcy were seen in patients with MDD compared to healthy individuals. Patients with MDD indicated significant decreases in cognitive scores (P < 0.001) in six modules: Speed of processing, working memory, visual learning, reasoning and problem-solving, social cognition, and total scores. Hcy levels showed a negative correlation with processing speed, social cognition, and total MDD scores (P < 0.05). Hcy was also significantly negatively correlated with Alistipes, Ruminococcae, Tenericides, and Porphyromonas (P < 0.05). CONCLUSION: Our results highlight that Hcy was correlated with cognition and gut microbiome in MDD. This interaction may be related to the physiological and pathological mechanisms underlying cognitive deficits in depression.
-
Changes in ruminal and reticular pH and bacterial communities in Holstein cattle fed a high-grain diet.
BACKGROUND: Subacute ruminal acidosis (SARA) is characterized by a ruminal pH depression, and microbiota can also be affected by a higher acidity and/or dietary changes. Previous studies have revealed similar patterns in pH reduction in the rumen and reticulum, whereas changes in reticular pH and bacterial community following a high-grain diet are not fully understood. The aim of this study was to investigate the changes in reticular pH and bacterial community structure following a high-grain diet simultaneously with those in the rumen. RESULTS: SARA was diagnosed when ruminal and reticular pH remained under 5.6 for 350 ± 14 and 312 ± 24 min/d, respectively, on the last day of the CON period. During the CON period, lower proportion of acetic acid and higher proportion of butyric acid were observed compared with the HAY period. The proportions of acetic acid and propionic acid were lower and higher, respectively, in the rumen compared with the reticulum. From 454 pyrosequencing analysis, the relative abundance of several genera differed significantly between the two periods and the two locations. During the HAY period, higher relative abundances of Prevotella, Eubacterium, Oscillibacter, and Succiniclasticum and lower relative abundances of Ruminococcus, Clostridium, and Olsenella were identified compared with the CON period. Furthermore, the relative abundance of Eubacterium was lower in the rumen compared with the reticulum. Bacterial diversity indices were significantly different between the HAY and CON periods, being higher in the HAY period. The quantitative real-time PCR showed that the copy numbers of several cellulolytic bacteria (Fibrobacter succinogenes and Ruminococcus albus) were higher during the HAY period. CONCLUSION: A high-grain diet showed similar impacts on the pH, fermentation, and bacterial community structure in the rumen and reticulum. During the CON period, ruminal and reticular pH decreased following the high-grain challenge, and lower bacterial diversity and changes in the bacterial composition, similarity, and bacterial copy numbers were observed due to a higher acidity and dietary changes compared with the HAY period. These changes may influence the fermentative ability of the rumen and reticulum.
-
Depression and fatigue in active IBD from a microbiome perspective-a Bayesian approach to faecal metagenomics.
BACKGROUND: Extraintestinal symptoms are common in inflammatory bowel diseases (IBD) and include depression and fatigue. These are highly prevalent especially in active disease, potentially due to inflammation-mediated changes in the microbiota-gut-brain axis. The aim of this study was to investigate the associations between structural and functional microbiota characteristics and severity of fatigue and depressive symptoms in patients with active IBD. METHODS: We included clinical data of 62 prospectively enrolled patients with IBD in an active disease state. Patients supplied stool samples and completed the questionnaires regarding depression and fatigue symptoms. Based on taxonomic and functional metagenomic profiles of faecal gut microbiota, we used Bayesian statistics to investigate the associative networks and triangle motifs between bacterial genera, functional modules and symptom severity of self-reported fatigue and depression. RESULTS: Associations with moderate to strong evidence were found for 3 genera (Odoribacter, Anaerotruncus and Alistipes) and 3 functional modules (pectin, glycosaminoglycan and central carbohydrate metabolism) with regard to depression and for 4 genera (Intestinimonas, Anaerotruncus, Eubacterium and Clostridiales g.i.s) and 2 functional modules implicating amino acid and central carbohydrate metabolism with regard to fatigue. CONCLUSIONS: This study provides the first evidence of association triplets between microbiota composition, function and extraintestinal symptoms in active IBD. Depression and fatigue were associated with lower abundances of short-chain fatty acid producers and distinct pathways implicating glycan, carbohydrate and amino acid metabolism. Our results suggest that microbiota-directed therapeutic approaches may reduce fatigue and depression in IBD and should be investigated in future research.
-
The Relationship Between Polycystic Ovary Syndrome (PCOS) and Depression.
OBJECTIVE: Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder, frequently accompanied by psychological comorbidities including depression. The aim of this narrative review is to summarise the latest research regarding potential contributors to and underpinning mechanisms of this relationship. DESIGN: A detailed search of the PubMed database was carried out beginning with systematic reviews and using the 'snowballing' method to identify further studies. The results yielded were assessed for quality using the GRADE framework. Depression in all studies was assessed using validated questionnaires. RESULTS: The association of PCOS and depression is bidirectional and multifactorial. The role of biological factors such as hyperandrogenism, metabolic dysregulation, chronic low-grade inflammation, gut microbiome, and genetic and epigenetic factors are highlighted. Also, psychosocial contributors includingillness perception (obesity, acne and hirsutism), menstruation, infertility issues, and sexual dysfunction, as well as eating disorders have a prevalent role. The majority of the studies included were systematic reviews and cross-sectional original research studies. CONCLUSION: Given the complex pathophysiology underpinning both diseases independently as well as in combination, despite evolving research, there is no single unifying link. However, this highlights the need for mental health risk stratification, addressing possible contributing factors, and offering the support required for patients with PCOS and depression.