Association of Short-Chain Fatty Acids with Gut Microbiota and Lipid Metabolism in Mice with Diarrhea Induced by High-Fat Diet in a Fatigued State

Effects of high-fat, low-carbohydrate enteral nutrition in critically ill patients: A systematic review with meta-analysis

BACKGROUND & AIMS

High-fat, low-carbohydrate enteral nutrition has gained attention, with expectations of an improved respiratory condition, fewer complications, and lower mortality. The present study performed a systematic review and meta-analysis of randomized controlled trials to examine the effects of high-fat, low-carbohydrate enteral nutrition in critically ill adult patients.

METHODS

We searched MEDLINE via Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), and ICHUSHI for randomized controlled trials comparing high-fat, low-carbohydrate enteral nutrition to standard enteral nutrition in critically ill adult patients who received enteral nutrition. The primary outcome was mortality. Secondary outcomes included intensive care unit (ICU) mortality, length of ICU stay, length of mechanical ventilation, and adverse events of diarrhea and gastric residual volume. We examined the risk of bias using the Cochrane risk-of-bias tool for randomized trials version 2. We assessed the overall certainty of evidence based on the Grading of Recommendations Assessment, Development, and Evaluation methodology. Synthesis results were calculated with risk ratios and 95% confidence intervals using a Mantel-Haenszel random-effects model.

RESULTS

Eight trials with 607 patients were included. The effects of high-fat, low-carbohydrate enteral nutrition on mortality did not significantly differ from those of standard enteral nutrition (62/280 [22.1%] vs. 39/207 [18.8%], risk ratios = 1.14, 95% confidence intervals 0.80 to 1.62, P = 0.47). No significant differences were observed in ICU mortality, ICU length of stay, diarrhea, or gastric residual volume between the two groups. However, high-fat, low-carbohydrate enteral nutrition was associated with a significantly shorter duration of mechanical ventilation (mean difference -1.72 days, 95% confidence intervals -2.93 to -0.50, P = 0.005).

CONCLUSION

High-fat, low-carbohydrate enteral nutrition may not affect mortality, but may decrease the duration of mechanical ventilation in critically ill adult patients. Limitations include the small number of studies and potential for bias. Further research is needed to confirm these results and investigate effects on other outcomes and in a subgroup of patients requiring mechanical ventilation.

Research progress of traditional Chinese medicine on the treatment of diarrhea by regulating intestinal microbiota and its metabolites based on renal-intestinal axis

Intestinal microbiota and its metabolites are involved in many physiological processes of the human body and play a vital role in maintaining human health. The occurrence of kidney disease can cause intestinal microbiota imbalance, resulting in diarrhea. The change of intestinal microbiota and its metabolites content can aggravate renal function injury, which has a bidirectional regulating effect. The theory of renal-intestinal axis further clarified that the impaired renal function is related to the imbalance of intestinal microorganisms, and the impaired intestinal barrier is related to the accumulation of toxin products. Because of its unique therapeutic advantages, Traditional Chinese Medicine can treat diarrhea by enhancing the growth of beneficial bacteria, inhibiting pathogenic bacteria and immune regulation, and slow down the continuous deterioration of kidney disease. This paper focuses on the relationship between intestinal microbiota and its metabolites and diarrhea, the influence of Traditional Chinese Medicine on intestinal microbiota in the treatment of diarrhea, and the role of intestinal microbiota and its metabolites in the renal-intestinal axis. It provides a theoretical basis for Traditional Chinese Medicine to regulate intestinal microbiota and its metabolites based on the renal-intestinal axis theory to treat nephrology-induced diarrhea, and also provides a new idea and method for Traitional Chinese Medicine to treat nephrology-induced diarrhea.

Shenling Baizhu powder attenuates lard diet in a fatigued state-induced diarrhea via targeting microbial metabolites short chain fatty acids-mediated lipid metabolism

Shenling Baizhu Powder (SLBZP), a traditional Chinese medicine (TCM) prescription renowned for its efficacy, is specifically recognized for its therapeutic effects in managing diarrhea associated with spleen qi deficiency. Our previous research has demonstrated that a lard diet in a fatigued state induced diarrhea belonging to spleen qi deficiency in TCM. Through a comprehensive investigation, we aimed to provide insights into the intricate relationship between SLBZP and the modulation of gut microbiota in alleviating symptoms associated with spleen qi deficiency-induced diarrhea. We induced diarrhea in mice by subjecting them to continuous standing on a multiple-platform apparatus while administering lard through intragastric administration for 14 days. Subsequently, we conducted gavage administration of SLBZP at a concentration of 0.637 g/ml for seven days. We observed a therapeutic effect of SLBZP on diarrhea induced by a lard diet in a fatigued state. SLBZP mitigated disorders in lipid metabolism and diminished hepatic oxidative responses. Additionally, SLBZP reversed gut microbiota dysbiosis of diarrheic mice and notably increased the production of short-chain fatty acids (SCFAs), primarily acetic acid, butyric acid, and valeric acid. Through correlation analysis, we additionally identified Lactobacillus reuteri and Lactobacillus intestinalis as potentially pivotal species associated with the therapeutic effects of SLBZP. We demonstrated that SLBZP exerts therapeutic effects on diarrhea caused by a lard diet in a fatigued state by repairing the intestinal mucosal barrier, improving lipid metabolism disorders, and regulating gut microbiota and metabolites SCFAs.

Fat and proteolysis due to methionine, tryptophan, and niacin deficiency leads to alterations in gut microbiota and immune modulation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is one of the intractable diseases. Nutritional components associated with IBD have been identified, and it is known that excessive methionine intake exacerbates inflammation, and that tryptophan metabolism is involved in inflammation. Analysis of the gut microbiota has also progressed, where Lactobacillus regulate immune cells in the intestine and suppress inflammation. However, whether the methionine and tryptophan metabolic pathways affect the growth of intestinal Lactobacillus is unknown. Here we show how transient methionine, tryptophan, and niacin deficiency affects the host and gut microbiota in mouse models of colitis (induced by dextran sodium sulfate) fed a methionine-deficient diet (1K), tryptophan and niacin-deficient diet (2K), or methionine, tryptophan, and niacin-deficient diet (3K). These diets induced body weight decrease and 16S rRNA analysis of mouse feces revealed the alterations in the gut microbiota, leading to a dramatic increase in the proportion of Lactobacillus in mice. Intestinal RNA sequencing data confirmed that the expression of several serine proteases and fat-metabolizing enzymes were elevated in mice fed with methionine, tryptophan, and niacin (MTN) deficient diet. In addition, one-carbon metabolism and peroxisome proliferator-activated receptor (PPAR) pathway activation were also induced with MTN deficiency. Furthermore, changes in the expression of various immune-related cytokines were observed. These results indicate that methionine, tryptophan, and niacin metabolisms are important for the composition of intestinal bacteria and host immunity. Taken together, MTN deficiencies may serve as a Great Reset of gut microbiota and host gene expression to return to good health.

Renshen Yangrong decoction for secondary malaise and fatigue: network pharmacology and Mendelian randomization study

Background

Renshen Yangrong decoction (RSYRD) has been shown therapeutic effects on secondary malaise and fatigue (SMF). However, to date, its bioactive ingredients and potential targets remain unclear.

Purpose

The purpose of this study is to assess the potential ingredients and targets of RSYRD on SMF through a comprehensive strategy integrating network pharmacology, Mendelian randomization as well as molecular docking verification.

Methods

Search for potential active ingredients and corresponding protein targets of RSYRD on TCMSP and BATMAN-TCM for network pharmacology analysis. Mendelian randomization (MR) was performed to find therapeutic targets for SMF. The eQTLGen Consortium (sample sizes: 31,684) provided data on cis-expression quantitative trait loci (cis-eQTL, exposure). The summary data on SMF (outcome) from genome-wide association studies (GWAS) were gathered from the MRC-IEU Consortium (sample sizes: 463,010). We built a target interaction network between the probable active ingredient targets of RSYRD and the therapeutic targets of SMF. We next used drug prediction and molecular docking to confirm the therapeutic value of the therapeutic targets.

Results

In RSYRD, network pharmacology investigations revealed 193 possible active compounds and 234 associated protein targets. The genetically predicted amounts of 176 proteins were related to SMF risk in the MR analysis. Thirty-seven overlapping targets for RSYRD in treating SMF, among which six (NOS3, GAA, IMPA1, P4HTM, RB1, and SLC16A1) were prioritized with the most convincing evidence. Finally, the 14 active ingredients of RSYRD were identified as potential drug molecules. The strong affinity between active components and putative protein targets was established by molecular docking.

Conclusion

This study revealed several active components and possible RSYRD protein targets for the therapy of SMF and provided novel insights into the feasibility of using Mendelian randomization for causal inference between Chinese medical formula and disease.

Dysfunction of cecal microbiota and CutC activity in mice mediating diarrhea with kidney-yang deficiency syndrome

Objective

Previous studies have indicated that diarrhea with kidney-yang deficiency syndrome leads to a disorder of small intestine contents and mucosal microbiota. However, the relationship of TMA-lyase (CutC) activity and TMAO with diarrhea with kidney-yang deficiency syndrome remains unexplored. Therefore, this study explores the relationship between cecal microbiota and choline TMA-lyase (CutC) activity, as well as the correlation between trimethylamine oxide (TMAO), inflammatory index, and CutC activity.

Method

Twenty SPF-grade male KM mice were randomly divided into the normal group (CN) and the diarrhea model group (CD). Diarrhea mouse models were established by adenine combined with Folium sennae administration. CutC activity, TMAO, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels were detected, and the cecal content microbiota was sequenced.

Result

After 14 days, diarrhea occurred in the CD group. Compared with the CN group, there was no significant change in the activity of CutC in the small intestine of the CD group, while the activity of CutC in the cecum was significantly increased, and the levels of TMAO, IL-6, and TNF-α showed a significant increase. The Chao1 index, Observed_species index, Shannon index, and Simpson index all exhibited a decreasing trend. The main changes at the bacterial genus level were Alistipes, Enterorhabdus, Desulfovibrio, Bacteroides, Candidatus_Saccharimonas, and [Ruminococcus]_torques_group. The results of LEfSe analysis, random forest analysis and ROC curve analysis revealed Paludicola, Blautia, Negativibacillus, Paraprevotella, Harryflintia, Candidatus_Soleaferrea, Anaerotruncus, Oscillibacter, Colidextribacter, [Ruminococcus]_torques_group, and Bacteroides as characteristic bacteria in the CD group. Correlation analysis showed a significant negative correlation between cecal CutC activity and Ligilactobacillus, and a significant positive correlation with Negativibacillus and Paludicola. The level of TMAO was significantly positively correlated with CutC activity and IL-6.

Conclusion

Diarrhea with kidney-yang deficiency syndrome significantly affects the physiological status, digestive enzyme activity, CutC activity, TMAO levels, and inflammatory response in mice. Additionally, there are changes in the composition and function of cecal microbiota, indicating an important impact of diarrhea with kidney-yang deficiency syndrome on the host intestinal microbiota balance. The occurrence of diarrhea with kidney-yang deficiency syndrome may be associated with dysbiosis of intestinal microbiota, increased CutC activity, elevated TMAO levels, and heightened inflammatory factor levels.

Gut microbiome and plasma metabolome alterations in myopic mice

Background

Myopia is one of the most common eye diseases leading to blurred distance vision. Inflammatory diseases could trigger or exacerbate myopic changes. Although gut microbiota bacteria are associated with various inflammatory diseases, little is known about its role in myopia.

Materials and methods

The mice were randomly divided into control and model groups, with the model group being attached-30D lens onto the eyes for 3 weeks. Then, mouse cecal contents and plasma were collected to analyze their intestinal microbiota and plasma metabolome.

Results

We identified that the microbial composition differed considerably between the myopic and non-myopic mice, with the relative abundance of Firmicutes phylum decreased obviously while that of Actinobacteria phylum was increased in myopia. Furthermore, Actinobacteria and Bifidobacterium were positively correlated with axial lengths (ALs) of eyeballs while negatively correlated with refractive diopters. Untargeted metabolomic analysis identified 141 differentially expressed metabolites, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed considerable enrichment mainly in amino acid metabolism pathways. Notably, pathways involved glutamate metabolism including "Glutamine and D-glutamate metabolism" and "Alanine, aspartate and glutamate metabolism" was changed dramatically, which presented as the concentrations of L-Glutamate and L-Glutamine decreased obviously in myopia. Interestingly, microbiome dysbiosis and metabolites alternations in myopia have a disrupting gut barrier feature. We further demonstrated that the gut barrier function was impaired in myopic mice manifesting in decreased expression of Occludin, ZO-1 and increased permeation of FITC-dextran.

Discussion

Myopic mice had obviously altered gut microbiome and metabolites profiles compared to non-myopic mice. The dysbiosis and plasma metabolomics shift in myopia had an interrupting gut barrier feature. Our study provides new insights into the possible role of the gut microbiota in myopia and reinforces the potential feasibility of microbiome-based therapies in myopia.