Short-chain Fatty Acid-producing Bacteria Research Articles

Phage cocktail alleviated type 2 diabetes by reshaping gut microbiota and decreasing proinflammatory cytokines.

Type 2 diabetes (T2D), a global health concern, is closely associated with the gut microbiota. Restoration of a balanced microbiota and intestinal homeostasis benefit therapy of T2D. Some special phages may selectively alter the gut microbiota without causing dysbiosis, such as MS2 and P22. However, scarcely systematic analysis of cascading effects triggered by MS2 and P22 phages on the microbiota, as well as interactions between specific gut bacteria and systemic metabolism, seriously inhibit the development of positive interventions of phages. Based on multi-omic analysis, we analyzed the intrinsic correlations among specific microbiota, their bioactive metabolites, and key indicators of T2D. We found that gavage of the MS2-P22 phage cocktail could significantly alter the gut microbiome to attenuate dysbiosis of diabetic C57BL/6 mice caused by high-fat diets (HFDs) and streptozotocin (STZ), by affecting microbial compositions as well as their metabolic pathways and metabolites, especially increasing amounts of short-chain fatty acid-producing (SCFA-producing) bacteria (e.g., Blautia and Romboutsia) and short-chain fatty acids (SCFAs). Correspondingly, a noteworthy reduction in the number of several opportunistic pathogens occurred, e.g., Candidatus Saccharimonas, Aerococcus, Oscillibacter, Desulfovibrio, and Clostridium sensu stricto 1. Synchronously, the levels of proinflammatory cytokines and lipopolysaccharide (LPS) were reduced to recover gut barrier function in T2D mice. These findings might benefit the development of a new dietary intervention for T2D based on phage cocktails. KEY POINTS: • Intestinal barrier integrity of T2D mice is improved by a phage cocktail • Negative relationship between Muribaculaceae and Corynebacterium reshaped gut microbiota • Acetate, propionate, and butyrate decreased the level of proinflammatory factors.

Super-comminuted dietary fiber from pomelo peel regulates blood lipids and gut microbiota and prevents obesity in high-fat diet-fed mice

This study investigated the inhibitory effects of super-comminuted dietary fiber from pomelo peel (SCPPDF) against high-fat diet (HFD)-induced obesity in mice. Mice were divided into five groups, which were fed with a normal diet, HFD, and HFD supplemented with low, medium, and high doses of SCPPDF for six weeks, respectively. Results showed that the SCPPDF supplementation effectively decreased the body weight and fat accumulation in liver and epididymal tissues in the HFD-fed mice, and decreased serum levels of triglycerides, low-density lipoprotein cholesterol, and total cholesterol. In addition, SCPPDF supplementation also decreased the Firmicutes to Bacteroidetes ratio (F/B), increased the relative abundances of short-chain fatty acids-producing bacteria, such as Lactobacillus, Bifidobacterium, and Allobaculum, reduced those of pathogenic bacteria, such as Staphylococcus and Corynebacterium_1, thereby regulating the HFD-induced imbalance of gut microbiota in mice. These findings indicated that SCPPDF could effectively inhibit obesity by regulating blood lipid levels, improving gut microbiota. SCPPDF has great potential to be developed into prebiotics or functional foods.

Dietary supplementation of proteases on growth performance, nutrient digestibility, blood characteristics and gut microbiota of growing pigs fed sorghum-based diets

Low-tannin sorghum is an excellent energy source in pig diets. However, sorghum contains several anti-nutritional factors that may have negative effects on nutrient digestibility. The impacts of proteases on growth performance, nutrient digestibility, blood parameters, and gut microbiota of growing pigs fed sorghum-based diets were studied in this study. Ninety-six pigs (20.66 ± 0.65 kg BW) were allocated into three groups (eight pens/group, four pigs/pen): (1) CON (control diet, sorghum-based diet included 66.98% sorghum), (2) PRO1 (CON + 200 mg/kg proteases), (3) PRO2 (CON + 400 mg/kg proteases) for 28 d. No differences were observed in growth performance and apparent total tract digestibility (ATTD) of nutrients between CON and PRO1 groups. Pigs fed PRO2 diet had increased (P < 0.05) BW on d 21 and 28, and increased (P < 0.05) average daily gain during d 14–21 and the overall period compared with pigs fed CON diet. In addition, pigs fed PRO2 diet had improved (P < 0.05) ATTD of gross energy, CP, and DM compared with pigs fed CON and PRO1 diets. Pigs fed PRO2 diet had lower (P < 0.05) plasma globulin (GLB) level and higher (P < 0.05) plasma glucose, albumin (ALB) and immunoglobulin G levels, and ALB/GLB ratio than pigs fed CON and PRO1 diets. Furthermore, pigs fed PRO2 diet had decreased (P < 0.05) the relative abundance of Acidobacteriota at the phylum level and increased (P < 0.05) the relative abundance of Prevotella_9 at the genus level. The linear discriminant analysis effect size analysis also showed that pigs fed PRO2 diet had significantly enriched short-chain fatty acid-producing bacteria, such as Subdoligranulum and Parabacteroides. In conclusion, protease supplementation at 400 mg/kg improved the growth performance of growing pigs fed sorghum-based diets, which may be attributed to the improvement of nutrient digestibility, host metabolism, immune status and associated with the altered gut microbiota profiles.

Growth performance, serum parameters, inflammatory responses, intestinal morphology and microbiota of weaned piglets fed 18% crude protein diets with different ratios of standardized ileal digestible isoleucine to lysine

The present study was to explore the Ile requirement of piglets fed 18% crude protein (CP) diets. Two hundred and fifty 28-day-old Duroc × Landrace × Yorkshire piglets (8.37 ± 1.92 kg) were randomly divided into 5 dietary treatments (10 piglets per replicate, 5 barrows and 5 gilts per replicate) with 45%, 50%, 55%, 60%, 65% standardized ileal digestible (SID) Ile-to-Lys ratios, and the SID Lys was formulated to 1.19%. The experimental design consisted of two phases (d 1 to 14 and d 15 to 28). Results showed that average daily gain (ADG) had a tendency to quadratically increase as the SID Ile-to-Lys ratio increased (P = 0.09), and the optimum SID Ile-to-Lys ratios required to maximize ADG were 48.33% and 54.63% for broken-line linear model and quadratic polynomial model, respectively. Different SID Ile-to-Lys ratios had no significant effects on average daily feed intake and gain-to-feed ratio. Dry matter (P < 0.01), CP (P = 0.01), ether extract (P = 0.04), gross energy (P < 0.01) and organic matter (P < 0.01) digestibility increased quadratically. Serum total cholesterol levels decreased linearly (P = 0.01) and quadratically (P < 0.01); aspartate aminotransferase (P < 0.01), interleukin-1β (P = 0.01), and tumor necrosis factor-α (P < 0.01) levels decreased quadratically; immunoglobulin G (P = 0.03) and immunoglobulin M (P = 0.01) concentrations increased quadratically. Serum Ser levels decreased linearly (P < 0.01) and quadratically (P = 0.01); Glu (P = 0.02), Arg (P = 0.05), and Thr (P = 0.03) levels decreased quadratically; Gly (P < 0.01) and Leu (P = 0.01) levels decreased linearly; Ile (P < 0.01) concentration increased linearly. Duodenal villus height (P < 0.01) and villus height to crypt depth ratio (P < 0.01) increased quadratically. The deficiency or excess of Ile decreased short chain fatty acid-producing bacteria abundance and increased pathogenic bacteria abundance. Overall, taking ADG as the effect index, the optimum SID Ile-to-Lys ratios of piglets offered 18% CP diets were 48.33% and 54.63% based on two different statistical models, respectively, and the deficiency or excess of lle negatively affected piglet growth rates and health status.

Arjunolic acid protects the intestinal epithelial barrier, ameliorating Crohn's disease-like colitis by restoring gut microbiota composition and inactivating TLR4 signalling

Background and AimsCrohn's disease (CD) is characterized by an overabundance of epithelial cell death and an imbalance in microflora, both of which contribute to the dysfunction of the intestinal barrier. Arjunolic acid (AA) has anti-apoptotic effects and regulates microbiota efficacy. The objective of this study was to assess the impact of the treatment on colitis resembling Crohn's disease, along with exploring the potential underlying mechanism. MethodsCD animal models were created using Il-10−/− mice, and the impact of AA on colitis in mice was evaluated through disease activity index, weight fluctuations, pathological examination, and assessment of intestinal barrier function. To clarify the direct role of AA on intestinal epithelial cell apoptosis, organoids were induced by LPS, and TUNEL staining was performed. To investigate the potential mechanisms of AA in protecting the intestinal barrier, various methods including bioinformatics analysis and FMT experiments were employed. ResultsThe treatment for AA enhanced the condition of colitis and the function of the intestinal barrier in Il-10−/− mice. This was demonstrated by the amelioration of weight loss, reduction in tissue inflammation score, and improvement in intestinal permeability. Moreover, AA suppressed the apoptosis of intestinal epithelial cells in Il-10−/− mice and LPS-induced colon organoids, while also reducing the levels of Bax and C-caspase-3. In terms of mechanism, AA suppressed the activation of TLR4 signaling in Il-10−/− mice and colon organoids induced by LPS. In addition, AA increased the abundance of short-chain fatty acid-producing bacteria in the stool of Il-10−/- mice, and transplantation of feces from AA-treated mice improved CD-like colitis. ConclusionsThe results of our study demonstrate that AA has a protective effect on the intestinal barrier in Crohn's disease-like colitis by preventing apoptosis. Additionally, this groundbreaking study reveals the capacity of AA to hinder TLR4 signaling and alter the makeup of the intestinal microbiome. The findings present fresh possibilities for treating individuals diagnosed with Crohn's disease. AA offers a hopeful novel strategy for managing Crohn's disease by obstructing crucial pathways implicated in intestinal inflammation and enhancing the gut microbiota.

Enhanced trimethylamine metabolism and gut dysbiosis in type 2 diabetes mellitus with microalbumin.

Abnormal gut microbiota and blood trimethylamine-N-oxide (TMAO) metabolome have been reported in patients with type 2 diabetes mellitus (T2DM) and advanced diabetic nephropathy. This study aimed to investigate the gut microbiota profiles and a group of targeted urine metabolic characteristics in T2DM patients with or without microalbuminuria, to determine the correlation between the gut microbiota composition, trimethylamine (TMA) metabolism, and the clinical features during progression of diabetic kidney disease (DKD). This study included 26 T2DM patients with microalbuminuria (Micro), 26 T2DM patients with normoalbuminuria (Normo), and 15 healthy controls (HC). Urine and Fecal samples were detected using ultra performance liquid chromatography tandem mass spectrometry and 16S ribosomal DNA gene sequencing, respectively. The TMAO/TMA ratio decreased gradually during the HC-Normo-Micro transition. The levels of TMA, choline and betaine were significantly different between the HC group and the T2DM patients belonging to both Normo and Micro groups. At the operational taxonomic unit (OTU) level, the gut microflora diversity was significantly reduced in the Micro groups compared to the HC groups and the Normo groups. Taxonomic analyses revealed significant consumption in the relative abundances of eight bacterial genera and significant enrichment of two bacterial genera during the HC-Normo-Micro transition. Furthermore, the relative abundances of six bacterial genera, namely, Ruminococcus_1, [Eubacterium]_ruminantium_group, Roseburia, Faecalibacterium, Fusicatenibacter and Coprococcus_3 exhibited significant differences, and were associated with elevated urinary albumin creatinine ratio (UACR), TMAO/TMA, TMA and its precursors in the Micro group compared with the other groups. The imbalance of gut microbiota has occurred in patients with early-stage DKD, and the consumption of short-chain fatty acid-producing bacteria were associated with the accumulation of TMA and UACR.

Isocaloric diets with varying protein levels affected energy metabolism in young adult Sprague-Dawley rats via modifying the gut microbes: A lipid imbalance was brought on by a diet with a particularly high protein content

Protein is the most important macro-nutrient when it comes to maximizing health, body composition, muscle growth, and recovery of body tissue. In recent years, it has been found that protein also plays an important role in metabolism and gut microbiota. This study was performed to investigate the effects of an isocaloric diet with different crude protein contents on the energy metabolism of Sprague-Dawley (SD) rats. Results revealed that compared with the 20% crude protein (CP; control) diet, the 38% CP diet improved serum parameters that are associated with dyslipidemia and glucose metabolic disorders in SD rats, whereas the 50% CP diet increased liver injury indicators and fatty acid synthesis-related genes and protein expression in the liver. Compared with the control diet, the 14% CP diet increased the abundance of colonic short-chain fatty acid-producing bacteria (Lachnospiraceae_NK4A136_group and Ruminiclostridium_9) and promoted colonic microbial cysteine and methionine metabolism, the 38% CP diet up-regulated colonic microbial lysine biosynthesis and degradation pathways, and the 50% CP diet down-regulated colonic mucosal cholesterol metabolism. Furthermore, the increase of multiple colonic enteropathogenic bacteria in the 50% CP group was associated with higher palmitic acid and stearic acid concentrations in the colonic microbes and lower cholesterol and arachidonic acid concentrations in the colonic mucosa. These findings revealed that the 14% CP and 38% CP diets improved rats' energy metabolism, while the 50% CP diet was accompanied by lipid metabolism imbalances and an increase in the abundance of multiple enteropathogenic bacteria.

Heart failure stimulates colorectal tumour growth through gut microbial alterations of specific populations

Abstract Background/purpose The field of reverse cardio-oncology has received growing attention in the last years, since epidemiological studies showed that patients with HF are at increased risk of developing cancer. In addition, HF can stimulate tumour growth directly in distant organs, including colon cancer. The exact mechanisms underlying this phenomenon, however, remain largely unknown. The connection between the microbiome and colorectal cancer (CRC) has been studied extensively and microbial dysbiosis in CRC is linked to cancer progression. Recent studies have also shown that HF patients display microbial dysbiosis. We hypothesized that microbial dysbiosis might contribute to HF-induced CRC tumour growth. Methods C57BL/6J mice were subjected to myocardial infarction (MI), with sham surgery as control. After six weeks faeces were collected, processed for 16s rRNA sequencing, and pooled for faecal microbial transplantation. CRC tumour growth was provoked in germ-free mice by treating them with Azoxymethane (AOM)/Dextran sodium sulphate (DSS). The CRC mice were transplanted with faeces from MI or sham mice. Disease progression was monitored using the disease severity score and endoscopy. After ten weeks mice were sacrificed, and tumour number and proliferation were quantified. All experimental procedures were performed in accordance with the European Union guidelines (CCD_8141, the Netherlands, LA_1400637, Belgium). Results MI-induced HF resulted in a decrease in microbial diversity (Shannon diversity p=0.018), characterized by a decrease in short chain fatty acid-producing bacteria, including the genera Blautia (p&amp;lt;0.01) and Roseburia (p&amp;lt;0.01). In addition, caecal butyrate levels were decreased in MI mice (p=0.029). These changes were largely comparable to microbial changes observed in HF patients and CRC patients. Interestingly, faecal transplantation with faeces from MI mice resulted in faster growth of CRC tumours in mice treated with AOM/DSS. This was demonstrated by a higher endoscopy score (7.9 ±2.5 vs. 10 ±2.4, p=0.038), indicative of worse disease progression, increased tumour counts (22 ±5.3 vs. 29 ±6, p&amp;lt;0.01), and a higher percentage of Ki67 positive cells in tumour tissue (p=0.012), relative to AOM/DSS treated mice transplanted with faeces from sham mice. Sequencing data revealed several differences in the microbial composition of mice transplanted with faeces from MI mice compared to mice transplanted with faeces from sham mice. Conclusion Our results demonstrate that HF induces microbial dysbiosis in mice. In addition, we show, for the first time, using a faecal transplantation model, that HF-induced microbial dysbiosis is causally involved in CRC tumour growth in a mouse model of CRC. Targeting the microbiome may present a tool to mitigate HF associated co-morbidities, especially cancer.Graphical abstract

Association Analysis of Gut Microbiota and Prognosis of Patients with Acute Ischemic Stroke in Basal Ganglia Region.

Previous studies have implied the potential impact of gut microbiota on acute ischemic stroke (AIS), but the relationships of gut microbiota with basal ganglia region infarction (BGRI) and the predictive power of gut microbiota in BGRI prognosis is unclear. The aim of this study was to ascertain characteristic taxa of BGRI patients with different functional outcomes and identify their predictive value. Fecal samples of 65 BGRI patients were collected at admission and analyzed with 16s rRNA gene sequencing. Three-month functional outcomes of BGRI were evaluated using modified Rankin Scale (mRS), and patients with mRS score of 0-1 were assigned to good-BGRI group while others were assigned to poor-BGRI group. We further identified characteristic microbiota using linear discriminant analysis effect size, and receiver operating characteristic (ROC) curve was used to determine the predictive value of differential bacteria. According to the mRS score assessed after 3 months of stroke onset, 22 patients were assigned to poor-BGRI group, while 43 patients were assigned to good-BGRI group. Short chain fatty acids-producing bacteria, Romboutsia and Fusicatenibacter, were characteristic microbiota of the good-BGRI group, while pro-inflammatory taxa, Acetanaerobacterium, were characteristic microbiota of the poor-BGRI group. Furthermore, the differential bacteria showed extensive associations with clinical indices. ROC curves, separately plotted based on Romboutsia and Fusicatenibacter, achieved area under the curve values of 0.7193 and 0.6839, respectively. This study identified the efficient discriminative power of characteristic microbiota in BGRI patients with different outcomes and provided novel insights into the associations of gut microbiota with related risk factors.

Prebiotic inulin enhances gut microbial metabolism and anti-inflammation in apolipoprotein E4 mice with sex-specific implications

Gut dysbiosis has been identified as a crucial factor of Alzheimer's disease (AD) development for apolipoprotein E4 (APOE4) carriers. Inulin has shown the potential to mitigate dysbiosis. However, it remains unclear whether the dietary response varies depending on sex. In the study, we fed 4-month-old APOE4 mice with inulin for 16 weeks and performed shotgun metagenomic sequencing to determine changes in microbiome diversity, taxonomy, and functional gene pathways. We also formed the same experiments with APOE3 mice to identify whether there are APOE-genotype dependent responses to inulin. We found that APOE4 female mice fed with inulin had restored alpha diversity, significantly reduced Escherichia coli and inflammation-associated pathway responses. However, compared with APOE4 male mice, they had less metabolic responses, including the levels of short-chain fatty acids-producing bacteria and the associated kinases, especially those related to acetate and Erysipelotrichaceae. These diet- and sex- effects were less pronounced in the APOE3 mice, indicating that different APOE variants also play a significant role. The findings provide insights into the higher susceptibility of APOE4 females to AD, potentially due to inefficient energy production, and imply the importance of considering precision nutrition for mitigating dysbiosis and AD risk in the future.

Shen-Ling-Bai-Zhu-San alleviates the imbalance of intestinal homeostasis in dextran sodium sulfate-induced colitis mice by regulating gut microbiota and inhibiting the NLRP3 inflammasome activation

Ethnopharmacological relevanceShen-Ling-Bai-Zhu-San (SLBZS) is a classic formula for strengthening the spleen and dispelling dampness, which has shown excellent efficacy in inflammatory bowel disease (IBD) in traditional Chinese medicine clinical studies. However, its exact pharmacological mechanism needs to be further elucidated. Aim of the studyThis study aims to investigate the restorative effect and mechanism of SLBZS on disturbed intestinal homeostasis in DSS-induced colitis mice. Materials and methodsA colitis model was induced by 3% dextran sulfate sodium (DSS) for seven days, and SLBZS was administered by gavage. The influence of SLBZS on DSS-induced clinical symptoms and disease activity index (DAI) was monitored and analyzed. Alcian blue and fluorescein isothiocyanate-conjugated wheat germ agglutinin (FITC-WGA) staining were used to assess intestinal mucus changes. The expression of intestinal barrier function indexes and immune-associated indexes were determined by H&E staining, real-time quantitative PCR (RT-qPCR), and Western blot. And gut microbiota changes were detected by 16S rDNA sequencing technology. The antibiotic experiment was used to explore the role of gut microbiota in SLBZS treatment. ResultsThe results showed that SLBZS significantly improved the physiological indexes including body weight, DAI score, and colon length of colitis mice. We focused on the effects of SLBZS on intestinal homeostasis in colitis mice. First, SLBZS could enhance the secretion of intestinal mucin and the expression levels of tight junctions and adhesive junctions. Second, SLBZS inhibited the expression level of inflammatory factors and reduced the protein expression level of NLRP3 inflammasome. Third, 16S rDNA sequencing analysis revealed that SLBZS repaired the dysfunctional gut microbiota of colitis mice, such as enhancing the abundance of short-chain fatty acid-producing bacteria including Faecalibaculum, Colidextribacter, and Coprococcus. Further, by gut microbiota-depleted mice, we found that SLBZS could not exert an anti-colitis effect when gut microbiota was absent. ConclusionsSLBZS restored intestinal environmental homeostasis by enhancing intestinal barrier function, inhibiting NLRP3 inflammasome, and restoring disturbed gut microbiota. And SLBZS could not ameliorate colitis mice with depleted gut microbiota. Our finding provided a theoretical basis for the clinical application of SLBZS in IBD.

High-Soluble-Fiber Diet Attenuates Hypoxia-Induced Vascular Remodeling and the Development of Hypoxic Pulmonary Hypertension.

Hypoxic pulmonary hypertension is a difficult disease to manage that is characterized by sustained elevation of pulmonary vascular resistance and pulmonary artery pressure due to vasoconstriction, perivascular inflammation, and vascular remodeling. Consumption of soluble-fiber is associated with lower systemic blood pressure, but little is known about its ability to affect the pulmonary circulation. Mice were fed either a low- or high-soluble-fiber diet (0% or 16.9% inulin) and then exposed to hypoxia (FiO2, 0.10) for 21 days to induce pulmonary hypertension. The impact of diet on right ventricular systolic pressure and pulmonary vascular resistance was determined in vivo or in ex vivo isolated lungs, respectively, and correlated with alterations in the composition of the gut microbiome, plasma metabolome, pulmonary inflammatory cell phenotype, and lung proteome. High-soluble-fiber diet increased the abundance of short-chain fatty acid-producing bacteria, with parallel increases in plasma propionate levels, and reduced the abundance of disease-related bacterial genera such as Staphylococcus, Clostridioides, and Streptococcus in hypoxic mice with parallel decreases in plasma levels of p-cresol sulfate. High-soluble-fiber diet decreased hypoxia-induced elevations of right ventricular systolic pressure and pulmonary vascular resistance. These changes were associated with reduced proportions of interstitial macrophages, dendritic cells, and nonclassical monocytes. Whole-lung proteomics revealed proteins and molecular pathways that may explain the effect of soluble-fiber supplementation. This study demonstrates for the first time that a high-soluble-fiber diet attenuates hypoxia-induced pulmonary vascular remodeling and the development of pulmonary hypertension in a mouse model of hypoxic pulmonary hypertension and highlights diet-derived metabolites that may have an immuno-modulatory role in the lung.

Hericium coralloides Ameliorates Alzheimer's Disease Pathologies and Cognitive Disorders by Activating Nrf2 Signaling and Regulating Gut Microbiota.

Alzheimer's disease (AD) is prone to onset and progression under oxidative stress conditions. Hericium coralloides (HC) is an edible medicinal fungus that contains various nutrients and possesses antioxidant properties. In the present study, the nutritional composition and neuroprotective effects of HC on APP/PS1 mice were examined. Behavioral experiments showed that HC improved cognitive dysfunction in APP/PS1 mice. Immunohistochemical and Western blotting results showed that HC reduced the levels of p-tau and amyloid-β deposition in the brain. By altering the composition of the gut microbiota, HC promoted the growth of short-chain fatty acid-producing bacteria and suppressed the growth of Helicobacter. Metabolomic results showed that HC decreased D-glutamic acid and oxidized glutathione levels. In addition, HC reduced the levels of reactive oxygen species, enhanced the secretion of superoxide dismutase, catalase, and glutathione peroxidase, inhibited the production of malondialdehyde and 4-hydroxynonenal, and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. Collectively, HC demonstrated antioxidant activity by activating Nrf2 signaling and regulating gut microbiota, further exerting neuroprotective effects. This study confirms that HC has the potential to be a clinically effective AD therapeutic agent and offers a theoretical justification for both the development and use of this fungus.

Prebiotic effect of poly-D-3-hydroxybutyrate prevents dyslipidemia in obese mice.

Obesity is a global health problem caused by genetic, environmental, and psychological factors and is associated with various health disorders. As such, there is a growing focus on the prevention of obesity and related diseases. The gut microbiota plays a crucial role in these diseases and has become a therapeutic target. Prebiotics, such as poly-d-3-hydroxybutyric acid (PHB), have gained attention for their potential to alter the gut microbiota, promote beneficial bacterial growth, and alleviate obesity. In this study, we examined the prebiotic effects of PHB in obese mice. We found that, in C57BL/6N mice, PHB reduced blood lipid levels. Analysis of the intestinal microflora also revealed an increase in short-chain fatty acid-producing bacteria. When PHB was administered to obese mice, subcutaneous fat and dyslipidemia were reduced, and the number of beneficial bacteria in the intestinal microflora increased. Furthermore, fatty degradation and oxidative stress were suppressed in the liver. PHB regulates gut bacterial changes related to obesity and effectively inhibits dyslipidemia, suggesting that it could be a prebiotic agent for curing various obesity-related diseases. In summary, PHB increases the beneficial gut microbiota, leading to an alleviation of obesity-associated dyslipidemia.

Distinct signatures of gut microbiota and metabolites in different types of diabetes: a population-based cross-sectional study

Patients with type 1 diabetes (T1D) and type 2 diabetes (T2D) present intestinal disturbances. Recent epidemiological data have showed that, worldwide, over half of newly diagnosed T1D patients were adults. However, the gut microbial alterations in adult-onset T1D are unclear. We aimed to identify the signatures of gut microbiota and metabolites in patients with adult-onset T1D systematically, comparing with T2D patients and healthy controls (HCs). This study enrolled 218 subjects from February 2019 to April 2022 (discovery cohort: 36HCs, 51 patients with adult-onset T1D and 56 patients with T2D; validation cohort: 28HCs, 27 patients with adult-onset T1D and 20 patients with T2D). Gut microbial profiles of the study subjects were investigated by metagenomic sequencing, and their faecal and serum metabolites were measured with targeted metabolomics. The study was registered on ClinicalTrials.gov (NCT05252728). Patients with adult-onset T1D had significant differences in the composition of bacteria and their metabolites, characterized by notable depletion of short-chain fatty acid-producing bacteria, especially Eubacterium rectale. This was associated with a severe loss of phenolic acids and their derivatives, including gallic acid (associated with glucose metabolism) and 3,4-dihydroxyhydrocinnamic acid (linked with glucose metabolism and pancreatic beta cell autoimmunity). A predictive model based on six bacteria and six metabolites simultaneously discriminated adult-onset T1D from T2D and HCs with high accuracy. Interestingly, bacterial-viral or bacterial-fungal trans-kingdom relationships, especially positive correlations between bacteriophages and beneficial bacteria, were significantly reduced in adult-onset T1D compared to HCs. Adult-onset T1D patients exhibit unique changes in host-microbiota-metabolite interactions. Gut microbiota and metabolite-based algorithms could be used as additional tools for differential diagnosis of different types of diabetes and beyond. National Key Research and Development Program of China, the National Natural Science Foundation of China.

Assessment of the influence on Hypsizygus marmoreus stem waste as a sustainable alternative to corn in Holdobagy geese dietary

The processing of edible mushrooms generates a large amount of mushroom residue. How to handle this mushroom residue in a way that avoids environmental pollution and maximizes effective utilization is a current issue that needs to be explored. This study aimed to investigate the effects of substituting dietary corn with Hypsizygus marmoreus mushroom stem waste (HSW) in the diet of geese. The control group was fed with a basal diet (BD), and the other groups were fed the basal diet to which 12% (HSW12 group), 24% (HSW24 group), or 32% (HSW32 group) of HSW were added to replace the equivalent proportion of corn. The test lasted 28 days. The results showed that the average daily feed intake (ADFI) of the HSW12 and HSW24 groups at 35–49 d, and the HSW12 and HSW32 groups at 35–63 d, was significantly higher compared to the BD group (p&amp;lt;0.05). The average daily gain (ADG) of the HSW12 group was significantly higher than BD at 35–49 d (p&amp;lt;0.05), but there was no significant difference in the feed/gain (F/G) among the groups. The levels of serum total protein (TP), albumin (ALB), globulin (GLOB), glutathione peroxidase (GSH-Px), and catalase (CAT) in HSW24 group were significantly higher than those in the BD group (p&amp;lt;0.05). Total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and malondialdehyde (MDA) decreased significantly, and there were no significant differences in carcass traits and meat quality. As 24% HSW supplementation had the best overall effect on the growth performance, serum biochemical indicators, meat quality, and carcass traits of geese, gut microbiota analysis was only performed on this group. The microbiota α-diversity of the cecum and ileum did not differ significantly between the BD and HSW24 groups. Principal coordinate analysis (PCoA) indicated that the difference in the cecum was significant in the β-diversity (p&amp;lt;0.05). Short chain fatty acid-producing bacteria and decomposing protein and carbohydrate bacteria (Prevotella) were enriched in the cecum in the HSW24 group. Gut immune regulating and nutritional bacteria, Lactococcus and Bacillus, respectively, were enriched in the ileum in HSW24 group. Spearman’s analysis indicated that Bacillus, Prevotella, and Clostridium were positively associated with serum protein and lipid metabolism. These results indicate that 24% HSW substitution of corn could improve goose serum ALB and fat metabolism, and increase serum antioxidant capacity, which may becaused by the improvement of goose cecal microbiota.

Multimodal immune cell phenotyping in GI biopsies reveals microbiome-related T cell modulations in human GvHD

Acute graft-versus-host disease (aGvHD) is a significant complication after allogeneic hematopoietic stem cell transplantation (aHSCT), but major factors determining disease severity are not well defined yet. By combining multiplexed tissue imaging and single-cell RNA sequencing on gastrointestinal biopsies from aHSCT-treated individuals with fecal microbiome analysis, we link high microbiome diversity and the abundance of short-chain fatty acid-producing bacteria to the sustenance of suppressive regulatory Tcells (Tregs). Furthermore, aGvHD severity strongly associates with the clonal expansion of mainly CD8 Tcells, which we find distributed over anatomically distant regions of the gut, persistent over time, and inversely correlated with the presence of suppressive Tregs. Overall, our study highlights the pathophysiological importance of expanded CD8 Tcell clones in the progression of aGvHD toward more severe clinical manifestations and strongly supports the further development of microbiome interventions as GvHD treatment via repopulation of the gut Treg niche to suppress inflammation.

877-P: Effects of SGLT2 Inhibitors on Gut Microbiota in Japanese Patients with Type 2 Diabetes

SGLT2 inhibitors (SGLT2is) promote urinary glucose excretion, thereby lowering blood glucose. In addition, SGLT2is have been reported to reduce body weight. However, the mechanism underlying the reduction in the body weight induced by SGLT2i remains to be elucidated. In this study, we investigated the effects of SGLT2is on the gut microbiota. A total of 36 Japanese patients with type 2 diabetes received SGLT2is for 3 months, and the prevalences of balance-regulating bacteria (12 types), which regulate the balance of the gut microbiota to maintain health, and balance-disturbing bacteria (6 types), which disturb the balance of the gut microbiota to cause disease, in the feces of the patients before and after 3 months of SGLT2i treatment were determined. Furthermore, the prevalences of short-chain fatty acid-producing bacteria (6 types), which are thought to be involved in body weight gain and weight loss, were also analyzed individually. The SGLT2i treatment was associated with a significant increase of the overall prevalence of the 12 types of balance-regulating bacteria. In addition, significant increases in the prevalences of the short-chain fatty acid-producing bacteria among the balance-regulating bacteria were also observed. However, the SGLT2i treatment had no effect on the balance-disturbing bacteria. Individual analyses of the balance-regulating bacteria revealed that the SGLT2i treatment was associated with a significant increase in the prevalence of Ruminococci, which are balance-regulating bacteria classified as short-chain fatty acid-producing bacteria. In conclusion, SGLT2i treatment was associated with an overall increase in the prevalence of balance-regulating bacteria. Among the balance-regulating bacteria, the prevalences of short-chain fatty acid-producing bacteria increased. Since short-chain fatty acids have been reported to prevent obesity, these results suggest that SGLT2is might induce body weight reduction via their actions on the gut microbiota. Disclosure M.Kusunoki: Research Support; Taisho Pharmaceutical Holdings Co., Ltd., Ono Pharmaceutical Co., Ltd., Daiichi Sankyo, Kaken Pharmaceutical Co., Ltd., Eli Lilly Japan K.K. F.Hisano: None. S.Matsuda: None. T.Miyata: None.

1620-P: Royal Jelly Improved Dysbiosis and Glucose Intolerance in db/db Mice

In this study, we have investigated the mechanisms of improvement of glucose intolerance via changes in gut microbiota using db/db mice. Eight-week-old db/m and db/db mice were divided into 5 groups and housed for eight weeks (n=6 for each group): db/m group without RJ (db/m), db/db mice without RJ (db/db), db/db mice with 0.2% RJ (db/db + 0.2% RJ), db/db mice with 1% RJ (db/db + 1% P), db/db mice with 5% RJ (db/db + 5% RJ) (Figure A). Body weight of db/db mice was higher than that of db/db mice fed with RJ (Figure B). Moreover, glucose tolerance evaluated by iPGTT and ITT were improved by RJ (Figure C-F). Next, the expression of inflammation-related genes (Tnfa, Ifng) and nutrient transporter genes (Cd36, Sglt1, and Pept1) in small intestine were increased in db/db mice more than in db/m mice, nevertheless significantly decreased by RJ (Figure G-K). In the gut microbiota analyses by 16S rRNA sequencing, it was found that seven taxa, including Firmicutes, were overexpressed in db/db mice, while seven taxa including short-chain fatty acid-producing bacteria such as the family Ruminococcaceae, the genus Butyricioccus, and the genus Acetiviblio were overexpressed in db/db +5%RJ mice in the LEfSe algorithm (Figure L). In summary, it is suggested that RJ might altere the gut microbiota and contributed to the improvement of metabolic disorders by changing the expression of genes related to nutrient absorption in the small intestine. Disclosure T. Okamura: Research Support; Yamada Bee Company, Inc. M. Hamaguchi: Research Support; Yamada Bee Company, Inc. H. Okamoto: Employee; Yamada Bee Company, Inc. N. Okumura: Employee; Yamada bee company, Inc. M. Fukui: None.

Metabarcoding of colonic cleansing fluid reveals unique bacterial members of mucosal microbiota associated with Inflammatory Bowel Disease

Background Inflammatory Bowel Disease (IBD) is a group of chronic idiopathic inflammatory diseases of the gastrointestinal (GI) tract associated with the dysbiosis of gut microbiota. Metabarcoding-based profiling of the gut microbiota of IBD patients is generally based on the stool samples collected from individual patients which rarely represent the mucosa-associated microbiota. The ideal sampling strategy for routine monitoring of the mucosal component of IBD has yet to be determined. Methods We hereby compare the microbiota composition of the colonic cleansing fluid (CCF) collected during colonoscopy with stool samples from IBD patients. The relationship between IBD and gut microbiota was revealed through the application of the 16S rRNA amplicon sequencing-based metabarcoding approach. CCF and stool samples were collected from IBD patients with Crohn’s disease and ulcerative colitis. Results The present study shows significant differences in the microbial composition of CCF samples, presumably indicating changes in the mucosal microbiota of IBD patients as compared to the control group. Short-chain fatty acid-producing bacteria under the family Lachnospiraceae, the actinobacterial genus Bifidobacterium, the proteobacterial Sutterella and Raoultella are found to contribute to the microbial dysbiosis of the mucosal flora in IBD patients. Conclusions CCF microbiota has the capacity to distinguish IBD patients from healthy controls and, thus, may constitute an alternative analysis strategy for the early diagnosis and disease progression in IBD biomarker research.