Evaluating the contribution of gut microbiome to the variance of porcine serum glucose and lipid concentration

Association of gastrointestinal microbiome and obesity with gestational diabetes mellitus-an updated globally based review of the high-quality literatures

OBJECTIVES

The purpose of this review is to investigate the relationship between gastrointestinal microbiome, obesity, and gestational diabetes mellitus (GDM) in an objective manner.

METHODS

We conducted a thorough and comprehensive search of the English language literatures published in PubMed, Web of Science, and the Cochrane Library from the establishment of the library until 12 December 2023. Our search strategy included both keywords and free words searches, and we strictly applied inclusion and exclusion criteria. Meta-analyses and systematic reviews were prepared.

RESULTS

Six high-quality literature sources were identified for meta-analysis. However, after detailed study and analysis, a certain degree of heterogeneity was found, and the credibility of the combined analysis results was limited. Therefore, descriptive analyses were conducted. The dysbiosis of intestinal microbiome, specifically the ratio of Firmicutes/Bacteroides, is a significant factor in the development of metabolic diseases such as obesity and gestational diabetes. Patients with intestinal dysbiosis and obesity are at a higher risk of developing GDM.

CONCLUSIONS

During pregnancy, gastrointestinal microbiome disorders and obesity may contribute to the development of GDM, with all three factors influencing each other. This finding could aid in the diagnosis and management of patients with GDM through further research on their gastrointestinal microbiome.

Extensive identification of serum metabolites related to microbes in different gut locations and evaluating their associations with porcine fatness

Gut microbiota plays important roles in host metabolism. Whether and how much the gut microbiota in different gut locations contributes to the variations of host serum metabolites are largely unknown, because it is difficult to obtain microbial samples from different gut locations on a large population scale. Here, we quantified the gut microbial compositions using 16S rRNA gene sequencing for 1070 samples collected from the ileum, cecum and faeces of 544 F6 pigs from a mosaic pig population. Untargeted metabolome measurements determined serum metabolome profiles. We found 1671, 12,985 and 103,250 significant correlations between circulating serum metabolites and bacterial ASVs in the ileum, cecum, and faeces samples. We detected nine serum metabolites showing significant correlations with gut bacteria in more than one gut location. However, most metabolite-microbiota pairwise associations were gut location-specific. Targeted metabolome analysis revealed that CDCA, taurine, L-leucine and N-acetyl-L-alanine can be used as biomarkers to predict porcine fatness. Enriched taxa in fat pigs, for example Prevotella and Lawsonia intracellularis were positively associated with L-leucine, while enriched taxa in lean pigs, such as Clostridium butyricum, were negatively associated with L-leucine and CDCA, but positively associated with taurine and N-acetyl-L-alanine. These results suggested that the contributions of gut microbiota in each gut location to the variations of serum metabolites showed spatial heterogeneity.

Gut Microbiota and Their Associated Metabolites in Diabetes: A Cross Talk Between Host and Microbes-A Review

Dysbiosis of the gut microbiota's composition and function is important in developing insulin resistance and diabetes. Diabetes has also been linked to changes in the circulating and fecal metabolites. Evidence suggests the associations between the gut microbiota and the aberrant diabetes-related metabolome. Metabolites play a crucial role in the host-microbiota interactions. Researchers have used a combination of metagenomic and metabolomic approaches to investigate the relationships between gut microbial dysbiosis and metabolic abnormalities in diabetes. We summarized current discoveries on the associations between the gut microbiota and metabolites in type 1 diabetes, type 2 diabetes, and gestational diabetes mellitus in the scoping review. According to research, the gut microbiota changes might involve in the development of diabetes through modulating the host's metabolic pathways such as immunity, energy metabolism, lipid metabolism, and amino acid metabolism. These results add to our understanding of the interplay between the host and gut microbiota metabolism.

Effects of Dietary Supplementation of Solubles from Shredded, Steam-Exploded Pine Particles on the Performance and Cecum Microbiota of Acute Heat-Stressed Broilers

Heat stress (HS) negatively influences livestock productivity, but it can be, at least in part, mitigated by nutritional interventions. One such intervention is to use byproducts from various sources that are likely to be included in the consumer chain. Thus, the present study investigated the effects of dietary supplementation of solubles from shredded, steam-exploded pine particles (SSPPs) on the performance and cecum microbiota in broilers subjected to acute HS. One-week-old Ross 308 broilers (n = 108) were fed 0%, 0.1%, or 0.4% SSPP in their diets. On the 37th day, forty birds were allocated to one of four groups; namely, a group fed a control diet without SSPPs at thermoneutral temperature (NT) (0% NT) and acute heat-stressed birds with 0% (0% HS), 0.1% (0.1% HS), and 0.4% (0.4% HS) SSPP-supplemented diets. The NT was maintained at 21.0 °C, while the HS room was increased to 31 °C. The final BW, percent difference in body weight (PDBW), and feed intake (FI) were lower in HS birds, but PDBW was reversely associated with dietary SSPP. Similarly, HS birds had a higher rectal temperature (RT) and ΔT in comparison to birds kept at NT. The FI of SSPP-supplemented birds was not significant, indicating lower HS effects. Plasma triglyceride was decreased in HS birds but not affected in 0.1% HS birds in comparison to 0% NT birds. OTUs and Chao1 were increased by 0.1% HS compared to 0% NT. Unweighted Unifrac distances for 0.1% HS were different from 0% NT and 0.4% HS. The favorable bacterial phylum (Tenericutes) and genera (Faecalibacterium and Anaerofustis) were increased, while the pathogenic genus (Enterococcus) was decreased, in SSPP-supplemented birds. In sum, production performances are negatively affected under acute HS. Dietary supplementation of SSPPs is beneficial for improving community richness indices and unweighted Unifrac distances, and it enhanced the advantageous bacterial phyla and reduced virulent genera and triglyceride hydrolysis in acute HS broilers. Our results indicate that dietary SSPPs modulates the microbial profile of the cecum while resulting in relatively less weight loss and lower rectal temperature compared to control.

Changes in Serum Fatty Acid Composition and Metabolome-Microbiome Responses of Heigai Pigs Induced by Dietary N-6/n-3 Polyunsaturated Fatty Acid Ratio

Changing fatty acid composition is a potential nutritional strategy to shape microbial communities in pigs. However, the effect of different n-6/n-3 polyunsaturated fatty acid (PUFA) ratios on serum fatty acid composition, microbiota, and their metabolites in the intestine of pigs remains unclear. Our study investigated the changes in serum fatty acid composition and metabolome–microbiome responses induced by dietary n-6/n-3 PUFA ratio based on a Heigai-pig model. A total of 54 Heigai finishing pigs (body weight: 71.59 ± 2.16 kg) fed with 3 types of diets (n-6/n-3 PUFA ratios are 8:1, 5:1, and 3:1) were randomly divided into 3 treatments with 6 replications (3 pigs per replication) for 75 days. Results showed that dietary n-6/n-3 PUFA ratio significantly affected biochemical immune indexes including glucose (Glu), triglycerides (TG), total cholesterol (TChol), non-esterified fatty acid (NEFA), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total thyroxine (TT4), and medium- and long-chain fatty acid composition, especially n-3 PUFA and n-6/n-3 PUFA ratio in the serum. However, no significant effects were found in the SCFAs composition and overall composition of the gut microbiota community. In the low dietary n-6/n-3 PUFA ratio group, the relative abundance of Cellulosilyticum, Bacteroides, and Alloprevotella decreased, Slackia and Sporobacter increased. Based on the metabolomic analysis, dietary n-6/n-3 PUFA ratio altered the metabolome profiles in the colon. Moreover, Pearson’s correlation analysis indicated that differential microbial genera and metabolites induced by different n-6/n-3 PUFA ratio had tight correlations and were correlated with the n-6 PUFA and n-3 PUFA content in longissimus dorsi muscle (LDM) and subcutaneous adipose tissue (SAT). Taken together, these results showed that lower dietary n-6/n-3 PUFA ratio improved serum fatty acid composition and metabolome–microbiome responses of Heigai pigs and may provide a new insight into regulating the metabolism of pigs and further better understanding the crosstalk with host and microbes in pigs.

Differential colitis susceptibility of Th1- and Th2-biased mice: A multi-omics approach

The health and economic burden of colitis is increasing globally. Understanding the role of host genetics and metagenomics is essential to establish the molecular basis of colitis pathogenesis. In the present study, we have used a common composite dose of DSS to compare the differential disease severity response in C57BL/6 (Th1 biased) and BALB/c (Th2 biased) mice with zero mortality rates. We employed multi-omics approaches and developed a newer vector analysis approach to understand the molecular basis of the disease pathogenesis. In the current report, comparative transcriptomics, metabonomics, and metagenomics analyses revealed that the Th1 background of C57BL/6 induced intense inflammatory responses throughout the treatment period. On the contrary, the Th2 background of BALB/c resisted severe inflammatory responses by modulating the host’s inflammatory, metabolic, and gut microbial profile. The multi-omics approach also helped us discover some unique metabolic and microbial markers associated with the disease severity. These biomarkers could be used in diagnostics.

Interactions Between the Aging Gut Microbiome and Common Geriatric Giants: Polypharmacy, Frailty, and Dementia

The gut microbiome has pervasive bidirectional relationships with pharmacotherapy, chronic disease, and physical and cognitive function. We conducted a narrative review of the current literature to examine the relationships between the gut microbiome, medication use, sarcopenia and frailty, and cognitive impairment. Data from in vitro experiments, in vivo experiments in invertebrates and complex organisms, and humans indicate associations between the gut microbiome and geriatric syndromes. Better understanding of the direct and indirect roles of the microbiome may inform future prevention and management of geriatric syndromes.

Dietary and Pharmacologic Manipulations of Host Lipids and Their Interaction With the Gut Microbiome in Non-human Primates

The gut microbiome influences nutrient processing as well as host physiology. Plasma lipid levels have been associated with the microbiome, although the underlying mechanisms are largely unknown, and the effects of dietary lipids on the gut microbiome in humans are not well-studied. We used a compilation of four studies utilizing non-human primates (Chlorocebus aethiops and Macaca fascicularis) with treatments that manipulated plasma lipid levels using dietary and pharmacological techniques, and characterized the microbiome using 16S rDNA. High-fat diets significantly reduced alpha diversity (Shannon) and the Firmicutes/Bacteroidetes ratio compared to chow diets, even when the diets had different compositions and were applied in different orders. When analyzed for differential abundance using DESeq2, Bulleidia, Clostridium, Ruminococcus, Eubacterium, Coprocacillus, Lachnospira, Blautia, Coprococcus, and Oscillospira were greater in both chow diets while Succinivibrio, Collinsella, Streptococcus, and Lactococcus were greater in both high-fat diets (oleic blend or lard fat source). Dietary cholesterol levels did not affect the microbiome and neither did alterations of plasma lipid levels through treatments of miR-33 antisense oligonucleotide (anti-miR-33), Niemann-Pick C1-Like 1 (NPC1L1) antisense oligonucleotide (ASO), and inducible degrader of LDLR (IDOL) ASO. However, a liver X receptor (LXR) agonist shifted the microbiome and decreased bile acid levels. Fifteen genera increased with the LXR agonist, while seven genera decreased. Pseudomonas increased on the LXR agonist and was negatively correlated to deoxycholic acid, cholic acid, and total bile acids while Ruminococcus was positively correlated with taurolithocholic acid and taurodeoxycholic acid. Seven of the nine bile acids identified in the feces significantly decreased due to the LXR agonist, and total bile acids (nmol/g) was reduced by 62%. These results indicate that plasma lipid levels have, at most, a modest effect on the microbiome, whereas bile acids, derived in part from plasma lipids, are likely responsible for the indirect relationship between lipid levels and the microbiome.

Flaxseed Oil and Heated Flaxseed Supplements Have Different Effects on Lipid Deposition and Ileal Microbiota in Albas Cashmere Goats

Simple Summary

With the grassland desertification intensified, pasture carrying capacity decreased, and grass seasonal changed, stall-feeding fattening has become an effective means to protect the natural environment. The stall-feeding fattening increased the cashmere goats’ weight but reduced the meat quality and increased the saturated fatty acids content in muscle and fat tissue of cashmere goats. Supplementing flaxseed and flaxseed oil rich-in linolenic acid (ALA) to diet to improve meat quality is an effective nutritional regulation means. Previous research results of our team showed that compared to diet supplemented with flaxseed oil, added flaxseed increased linoleic acid biohydrogenation by reducing the Ruminobacter relative abundance and increasing the relative abundance of Prevotellaceae_UCG-001 and Fretibacterium in rumen, protected ALA away from biohydrogenation, and more n-3 polyunsaturated fatty acids entered the post-intestinal tract. Based on the previous research, this study explored whether the ALA flowing into the posterior intestine can reduce fat deposition and blood lipid by affecting intestinal microbiota. The results showed that adding flaxseed grain to diet decreased the growth performance, lipid deposition, and blood lipid content of goats by regulating the blood lipid-related enzyme activity, which positively associated with [Eubacterium]_coprostanoligenes_group, but negatively associated with unclassified_f_Peptostreptococcaceae, Intestinibacter, and Ruminococcus_2.

Abstract

The present study investigated the effect of flaxseed grain or flaxseed oil on ileal microbiota and lipid deposition of cashmere goats. Sixty kid goats (average body weight 18.6 ± 0.1 kg) were allocated to three treatments, fed for 90 days, with control treatment: basal diet (CON, total-mixed ration), experimental treatment: basal diet with added flaxseed oil (LNO), experimental treatment: basal diet with added heated flaxseed grain (HLS). The final body weight, body weight gain, the weight of kidney fat, omental fat, tail fat, and fat tissue, the activity of fatty acid synthetase, acetyl-coa carboxylase, and malic dehydrogenase, and the relative abundance (RA) of unclassified_f_Peptostreptococcaceae and Intestinibacter were remarkably higher in the LNO treatment than in the HLS treatment, but the [Eubacterium]_coprostanoligenes_group RA showed the opposite result. The content of triglyceride, cholesterol, and low-density lipoprotein cholesterol were significantly higher in the CON and LNO treatments than in the HLS treatment, while the hormone-sensitive lipase activity and the non-esterified fatty acid content showed the opposite result. In conclusion, the flaxseed grain is more efficient than flaxseed oil in ameliorating the blood lipid profiles and it is a potential product for decreasing the lipid deposition of cashmere goats.

Altered gut bacterial and metabolic signatures and their interaction in gestational diabetes mellitus

Emerging evidence indicates that the gut microbiome can modulate metabolic homeostasis, and thus may influence the development of gestational diabetes mellitus (GDM). However, whether and how the gut microbiome and its correlated metabolites change in GDM is uncertain. Herein we compare the gut microbial compositions, and fecal and urine metabolomes, of 59 patients with GDM versus 48 pregnant healthy controls (HCs). We showed that the microbial and metabolic signatures of GDM patients were significantly different from those of HCs. Compared to HCs, the GDM subjects were characterized by enriched bacterial operational taxonomic units (OTUs) of the family Lachnospiraceae, and depleted OTUs of the families Enterobacteriaceae and Ruminococcaceae. Some altered gut microbes were significantly correlated with glucose values and fetal ultrasonography indexes. Moreover, we identified four fecal and 15 urine metabolites that discriminate GDM from HC. These differential metabolites are mainly involved in carbohydrate and amino acid metabolism. Significantly, co-occurrence network analysis revealed that Lachnospiraceae and Enterobacteriaceae bacterial OTUs formed strong co-occurring relationships with metabolites involved in carbohydrate and amino acid metabolism, suggesting that disturbed gut microbiome may mediate GDM. Furthermore, we identified a novel combinatorial marker panel that could distinguish GDM from HC subjects with high accuracy. Together our findings demonstrate that altered microbial composition and metabolic function may be relevant to the pathogenesis and pathophysiology of GDM.

Unraveling Host-Gut Microbiota Dialogue and Its Impact on Cholesterol Levels

Disruption in cholesterol metabolism, particularly hypercholesterolemia, is a significant cause of atherosclerotic cardiovascular disease. Large interindividual variations in plasma cholesterol levels are traditionally related to genetic factors, and the remaining portion of their variance is accredited to environmental factors. In recent years, the essential role played by intestinal microbiota in human health and diseases has emerged. The gut microbiota is currently viewed as a fundamental regulator of host metabolism and of innate and adaptive immunity. Its bacterial composition but also the synthesis of multiple molecules resulting from bacterial metabolism vary according to diet, antibiotics, drugs used, and exposure to pollutants and infectious agents. Microbiota modifications induced by recent changes in the human environment thus seem to be a major factor in the current epidemic of metabolic/inflammatory diseases (diabetes mellitus, liver diseases, inflammatory bowel disease, obesity, and dyslipidemia). Epidemiological and preclinical studies report associations between bacterial communities and cholesterolemia. However, such an association remains poorly investigated and characterized. The objectives of this review are to present the current knowledge on and potential mechanisms underlying the host-microbiota dialogue for a better understanding of the contribution of microbial communities to the regulation of cholesterol homeostasis.

Dairy Propionibacterium freudenreichii ameliorates acute colitis by stimulating MUC2 expression in intestinal goblet cell in a DSS-induced colitis rat model

An intact mucus layer is important in managing inflammatory bowel disease (IBD). Dairy Propionibacterium freudenreichii has probiotic potential, produces propionic acid and is known to promote health. The aim of this study was to evaluate the effects of P. freudenreichii on the improvement of colitis. LS 174T goblet cells and a dextran sodium sulfate (DSS)-induced colitis rat model were used to investigate the P. freudenreichii-induced stimulation of mucin production in vitro and in vivo, respectively. The mRNA and protein expression levels of MUC2, a main component of intestinal mucus, increased in the supernatant of P. freudenreichii culture (SPFC)-treated LS 174 cells. The SPFC and live P. freudenreichii (LPF) reduced the disease activity index (DAI) in the rats with DSS-induced colitis. After treatment with SPFC or LPF, the mRNA levels of typical pro-inflammatory cytokines decreased and the inflammatory state was histologically improved in the rats with DSS-induced colitis. The SPFC and LPF treatments increased the gene and protein expression levels of MUC2 in the rats with DSS-induced colitis compared with the expression levels in the negative control rats, and immunohistochemistry (IHC) showed an increase of the intestinal MUC2 level. In addition, SPFC and LPF augmented the level of propionate in the faeces of the rats with DSS-induced colitis. In conclusion, P. freudenreichii might improve acute colitis by restoring goblet cell number and stimulating the expression of MUC2 in intestinal goblet cells.

Distinct Gut Microbiota and Serum Metabolites in Response to Weight Loss Induced by Either Dairy or Exercise in a Rodent Model of Obesity

Energy imbalance is a primary cause of obesity. While the classical approach to attenuate weight gain includes an increase in energy expenditure through exercise, dietary manipulation such as the inclusion of dairy products has also been proven effective. In the present study, we explored the potential mechanisms by which dairy and exercise attenuate weight gain in diet-induced obese rats. Male Sprague-Dawley rats were fed a high fat, high-sugar (HFHS) diet to induce obesity for 8 weeks. Rats were then further grouped into either control (HFHS + casein) or dairy diet (HFHS + nonfat skim milk) with and without treadmill exercise for 6 weeks. Serum and fresh fecal samples were collected for gut microbiota, serum metabolomics, and metallomics analysis. Diet and exercise resulted in distinct separation in both gut microbiota and serum metabolite profiles. Most intriguingly, obesogenic bacteria including Desulfovibrio and Oribacterium were reduced, and bioactive molecules such as mannose and arginine were significantly increased in the dairy group. Correlations of at least six bacterial genera with serum metal ions and metabolites were also found. Results reveal distinct impacts of dairy and exercise on the gut microbiota and in the modulation of circulating metabolites with the former primarily responsible for driving microbial alterations known to attenuate weight gain.

Natural Products for the Treatment of Autoimmune Arthritis: Their Mechanisms of Action, Targeted Delivery, and Interplay with the Host Microbiome

Rheumatoid arthritis (RA) is a chronic, debilitating illness characterized by painful swelling of the joints, inflammation of the synovial lining of the joints, and damage to cartilage and bone. Several anti-inflammatory and disease-modifying drugs are available for RA therapy. However, the prolonged use of these drugs is associated with severe side effects. Furthermore, these drugs are effective only in a proportion of RA patients. Hence, there is a need to search for new therapeutic agents that are effective yet safe. Interestingly, a variety of herbs and other natural products offer a vast resource for such anti-arthritic agents. We discuss here the basic features of RA pathogenesis; the commonly used animal models of RA; the mainstream drugs used for RA; the use of well-characterized natural products possessing anti-arthritic activity; the application of nanoparticles for efficient delivery of such products; and the interplay between dietary products and the host microbiome for maintenance of health and disease induction. We believe that with several advances in the past decade in the characterization and functional studies of natural products, the stage is set for widespread clinical testing and/or use of these products for the treatment of RA and other diseases.