Short-chain Fatty Acid Profiles Research Articles

P1337 High fat diet drives increased dysbiosis in IBD compared to healthy controls

Abstract Background High fat diets (HFD), consisting of low fibre intake and high fat are associated with increased IBD risk. Industrialised diets have known impacts on host health but also impact the gut microbiota1; known to be altered in IBD. Whilst fat is primarily digested in the upper GI tract excess fat travels to the colon, the hub of microbial activity. In this study, microbial community changes in response to HFD were compared in a healthy and IBD patient donor using in vitro continuous culture chemostats. Methods Stool from a healthy donor and a de novo, treatment naive IBD patient were used to seed independent bioreactors. Standard diet was fed until microbial stabilisation followed by 14 days of HFD. Standard diet was then resumed for a 14-day recovery period. Daily sampling was used to assess changes in microbial composition (16S rRNA amplicon sequencing) and function (short chain fatty acids (SCFA) measured by gas-chromatography mass spectrometry). Results Despite comparable bacterial densities at stability the IBD vessel had higher total SCFA output compared to healthy. SCFA profiles were unique between donors with higher acetate and propionate concentration in the IBD vessel (p<0.0086). Butyrate at stability, however, was higher in the healthy vessel (p=0.025). HFD resulted in a depletion of acetate and propionate in both donors and an increase in isobutyrate, isovalerate, heptanoate and octanoate. Following transfer back to standard diet, the healthy vessel remained depleted of propionate (p= 0.0009) and butyrate remained significantly depleted in the IBD vessel (p= 0.0034) and did not recover (stable: recovery; p<0.0001). Healthy only: HFD significantly lowered microbial (alpha) diversity by observed and Shannon metrics (p<0.034) but was unchanged in Chao1 index. By recovery alpha diversity realigned with the stable phase. Beta diversity showed unique composition across each experimental phase (p<0.02). HFD saw a depletion of Faecalibacterium and Blautia in favour of Escherichia-Shigella and Parasutterella genera. Sequence analysis of the IBD vessel is underway. Conclusion HFD affected both HC and IBD microbial communities; isovalerate and isobutyrate levels increased indicating greater amino acid (protein) metabolism by community members. Higher levels of heptanoate and octanoate are indicative of increased fatty acid degradation. The healthy donor had a more robust recovery with only 5 SCFAs remaining altered. In comparison, 8 metabolites remaining altered in IBD with a dramatic impact on butyrate production highlighting the greater fragility in the IBD microbiome. The findings support the need for further mechanistic understanding of the role of diet and microbial changes in IBD.

P1319 Multi-omic modelling of antibiotic perturbed faecal microbial communities demonstrates reduced microbial resilience in IBD

Abstract Background Excessive antibiotic use is a risk factor in IBD, due to the impact on the gastrointestinal microbiota, but the extent of impact on microbial metabolite production is unknown. Here we investigate the impact of ciprofloxacin (CIP) and metronidazole (MTZ) on gut microbiota structure/function in a healthy donor and a new-onset therapeutic naïve IBD patient. We also investigate the use of autologous faecal microbiota transplant (aFMT) as a microbial therapeutic to assist recovery of the gut ecosystem. Methods Donor faecal specimens (IBD or healthy) were used to inoculate twin chemostat vessels. Following community stabilisation, vessels were dosed daily with CIP or MTZ for 7 days. In the healthy donor vessel, 4 doses of aFMT were administered over 7 days (post antibiotics) followed by a 7-day recovery. In the IBD vessels no FMT was administered. Vessels were sampled daily to monitor microbial profiles (16S rRNA sequencing) and short chain fatty acid (SCFA) profiles (GC-MS). Results CIP in the healthy vessel caused a significant depletion of acetate, butyrate and propionate, remaining significantly depleted during aFMT. CIP dosing also resulted in an enrichment of Escherichia-Shigella and Enterobacter and a loss of Akkermansia, Faecalibacterium and Bacteroides. During recovery acetate and propionate recovered whilst butyrate remained depleted (p=0.004). In the healthy MTZ vessel, acetate increased during antibiotic dosing and was restored following aFMT. Butyrate decreased during MTZ dosing and remained significantly decreased (p<0.031). Propionate levels also reduced following MTZ but were found in highest abundance during aFMT and recovery phases (p<0.038). Parabacteroides increased during MTZ dosing which subsequently decreased to stable abundance. Akkermansia was significantly increased in recovery phase compared to aFMT and stability phases. In the IBD donor, CIP caused a significant reduction in 10 SCFAs and several taxa including Bacteroides and Dialister genera alongside an enrichment of Enterococcus, Lachnospiraceae, Anaerofilum and Eisenbergiella. MTZ treatment resulted in a less dramatic reduction in SCFAs. Microbial community changes included an enrichment of Escherichia-Shigella, Enterococcus and Parasutterella and a depletion of Alistipes and Dialister. Conclusion CIP and MTZ significantly depleted levels of beneficial genera and reduced the abundance of SCFAs. Neither donor community was able to fully restore composition or function. aFMT modulated the healthy donor microbial communities to a "new healthy". Further investigation into long-term antibiotic treatment and the use of microbial therapeutics is needed to fully understand this relationship in the context of IBD.

Enhancing digestion and gut fermentation in pigs: in vitro evaluation of the effects of reconstituted and ensiled sorghum grains

ABSTRACT The effect of ensiling sorghum grains harvested at different dates on pig nutrient digestibility and fermentability was evaluated using in vitro approaches. A sorghum crop was divided following a randomised complete block design and distributed in 3 treatments: 1) grain harvested 113 d after sowing (40% moisture) and ensiled for 180 d (high moisture, HMG), 2) grain harvested 159 d after sowing (15% moisture), rehydrated to 40% moisture and ensiled for 180 d (reconstituted, REC), and 3) sorghum grain harvested 159 d after sowing (15% moisture) and stored dry (dry, DG). Starch content was lower in ensiled grains (HMG and REC) (p = 0.019), and lower for HMG (p = 0.043). The resistant starch fraction was lower (p < 0.001), and the predicted glycaemic index was higher (p = 0.029) in ensiled grains. In vitro DM, OM and starch digestibility were greater in ensiled grains (p < 0.001 for all parameters). Ensiled grains had lower in vitro gas production [ml/g DM] (p = 0.002), but the rate of gas production [ml/h] was higher (p = 0.025). Finally, ensiled grains had lower butyrate and higher branched-chain fatty acids concentration [mol/L] (p < 0.001 and p < 0.003, respectively). The ensiling process improved in vitro digestibility and changed fermentation parameters and short-chain fatty acids profile, regardless of DM at harvest.

Effect of multispecies fungal extract supplementation on growth performance, nutrient digestibility, ruminal fermentation, and the rumen microbiome composition of beef cattle fed forage-based diets.

Our objective was to evaluate the effect of a multispecies fungal extract (MFE) on growth performance, apparent total tract digestibility (ATTD), fermentation characteristics, and rumen microbiome composition of beef cattle fed forage-based diets. For experiment 1, ruminally cannulated Angus × SimAngus cows (n = 4; body weight [BW] = 569 ± 21kg) were used in a randomized crossover design with two 21-d study periods and a 23-d washout period to evaluate the effect of dietary inclusion of an MFE on in situ digestion, ruminal fermentation, and the composition of the rumen microbiome. Treatments consisted of a forage-based diet with or without the inclusion of a MFE. Rumen samples were collected on days 5, 10, and 20. Experiment 2 evaluated different inclusion rates of the MFE in a randomized complete block design using Angus × SimAngus-crossbred steers (n = 80; BW = 370 ± 44kg). Steers were blocked by BW and randomly assigned to one of four treatments (2 pens/treatment): diet with no MFE, 0.02%, 0.04%, and 0.08% of the MFE (dry matter [DM] basis). Steers were fed a forage-based diet for 122 d. Subsets of 10 steers/treatment were randomly selected for the determination of ATTD on d 20, 40, and 60. All data were analyzed using the MIXED procedure of SAS. In exp 1, adding the MFE to the diet tended to increase the ruminal disappearance rate of the DM on day 10 (P = 0.06). No interactions or treatment effects were observed for the short-chain fatty acid profile of the rumen fluid (P ≥ 0.13). Metagenomic analysis of the rumen microbiome showed an MFE × d interaction for the Fibrobacter genus (P = 0.01), which on day 20 was less abundant in the rumen of cows fed the MFE. In exp 2, steers supplemented with 0.04% of MFE had a lower average daily gain and were lighter at the end of the experiment (cubic, P ≤ 0.04) compared to steers supplemented with 0.02% MFE. Steers fed the diet with 0.02% of MFE had the greatest gain-to-feed ratio among the MFE-supplemented groups (cubic, P < 0.01). Dietary inclusion of the MFE increased neutral detergent fiber digestibility (linear, P = 0.05). Steers supplemented with 0.04% of MFE had the greatest acid detergent fiber digestibility among treatments (quadratic, P = 0.03). Collectively, results showed that ruminal disappearance rate and digestibility of forage-based diets increased due to MFE supplementation, but did not translate into growth performance improvements or beneficially alter rumen fermentation.

OM-85 attenuates high-fat diet-induced obesity, insulin resistance, gut dysbiosis and nonalcoholic steatohepatitis in a murine model

BackgroundObesity is a global epidemic that is tied to a wide range of human disorders. Chronic consumption of a high-fat diet is linked to disruption of the intestinal microbiome, which drives obesity-related pathophysiology. Broncho-Vaxom® (OM-85), a bacterial lysate used for prophylaxis of recurrent respiratory tract infections, has both immunostimulatory and immunomodulatory functions. MethodsMale C57Bl/6 mice were maintained on normal control vs. high-fat diets for 8 weeks and treated or untreated with OM-85 or with the probiotic Lactobacillus plantarum, as a positive control. Mice were evaluated for weight gain, glucose tolerance, insulin tolerance, gut microbiome composition and non-alcoholic steatohepatitis (NASH). ResultsHigh-fat diet mice developed obesity, insulin resistance, NASH and gut dysbiosis with a shift from the Bacteroidetes phylum, such as Bacteroidales order and Muribaculaceae family organisms to Firmicutes groups, such as the Clostridium and Blautia genuses. Treatment with OM-85 led to 1) prevention of obesity, 2) prevention of insulin resistance, 3) attenuation of NASH and 4) attenuation of gut dysbiosis, with decreased levels of the organisms mentioned above and increases in Verrucomicrobiae phylum organisms such as Akkermansia family microbes as well as Muribaculaceae organisms. These shifts in the gut microbiome predict favorable effects on the short chain fatty acid profile in the gut and increased integrity of the intestinal barrier. Pathway analysis showed that OM-85 decreases rates of carbohydrate metabolism, providing an additional mechanism whereby OM-85 prevents obesity. ConclusionImmune modulators such as OM-85 should be investigated for their potential therapeutic effects on metabolism.

Short and Medium-chain Fatty Acid Profile of Goat Milk Fed with Pineapple Peel Silage

This study aims to determine the profile of short-chain fatty acids (SCFA) and medium-chain fatty acids (MCFA) in goat milk-fed pineapple peel silage. The pineapple waste was milled and mixed with 5% (w/w) of rice brand, put into an anaerobic plastic bag, and stored for 21 days to produce pineapple peel silage. The materials used in this research were 12 female Etawa cross-breed dairy goats allocated into randomized block designs with four kinds of feed treatments and three groups of lactation periods. The feed treatments were P0 (60% forage + 40% concentrate); P1 (30% forage + 30% pineapple peel silage + 40% concentrate); P2 (15% forage + 45% pineapple peel silage + 40% concentrate); P3 (60% pineapple peel silage + 40% concentrate). Forage contains native grass and rubber leaves. The concentrate consists of 58% bran, 25% fine corn, 6% soybean meal, 9% coconut meal, 1% mineral mixture, and 1% salt. The variables observed were feed consumption, fat milk, and short-chain and medium-chain milk fatty acids. The data obtained were analyzed using ANOVA, and if there were differences between treatments, a Duncan test. The result of this study showed that the use of pineapple peel silage as a forage source had affected the feed consumption (P&lt;0.05) but did not significantly affect SCFA acid and MCFA profile (P&gt; 0.05) in goat milk. Using pineapple peel silage as forage replacement up to 45 % in Fed, the dairy Ettawa cross-breed (EC) goat’s diet significantly affects the short-chain and medium-chain fatty acids profile. The content of short-chain fatty acids and medium-chain fatty acids in goat's milk decreases, and there is no musty smell due to the addition of pineapple peel silage in the feed.

High-fiber basil seed flour reduces insulin resistance and hepatic steatosis in high-fat diet mice

The incidence of insulin resistance (IR) and hepatic steatosis is increasing, with dietary fiber playing a protective role against these disorders. Ocimum basilicum L., widely used in food, pharmaceutical, and cosmetic industries, but their health-promoting properties remain underexplored. This study evaluated the effects of a fiber-rich fraction of partially defatted basil seeds (BSF) on IR, hepatic steatosis, and polyunsaturated fatty acid and short-chain fatty acid (SCFA) profiles in high-fat diet (HFD)-fed C57BL/6 J male mice. Mice were assigned to four groups and fed either a control diet or HFD, supplemented with BSF or oat flour for 4 weeks. HFD induced IR, hepatic steatosis, proinflammatory state, and a significant decreased in SCFA production. In contrast, supplementation with BSF attenuated IR, steatosis, liver damage, oxidative stress, and inflammation, while increasing n-3 polyunsaturated fatty acids in liver, adipocytes, and erythrocytes, and enhancing SCFA production, suggesting potential therapeutic benefits in managing these conditions.

A comprehensive study of the whole profiles of short-chain fatty acids in milk

Despite milk contains low levels of short-chain fatty acids (SCFA), these levels are higher than in plant oils and still exhibit significant biological activity. However, data regarding SCFA in milk are limited and fragmented. Therefore, our study utilized a laboratory-established method to analyze the SCFA profiles of milk from different species, geographical regions, and heat treatments. Our results revealed that SCFA composition of milk from Holstein cow, buffalo, ewe, and goat differs markedly from that of human, camel, and donkey, with camel and donkey displaying relatively similar SCFA composition. Furthermore, significant variations in SCFA content and composition were observed among different geographical regions. Additionally, significant volatilization losses of SCFA were noted due to the heat treatment of ultra-high temperature sterilization (137°C for 4s). Overall, species were found to be the major factor influencing total SCFA. This study provides substantial data to support a comprehensive investigation into the content and composition of SCFA in milk.

Lactobacillus reuteri or Lactobacillus rhamnosus GG intervention facilitates gut barrier function, decreases corticosterone and ameliorates social behavior in LPS-exposed offspring

Probiotic therapy with Lactobacillus reuteri and Lactobacillus rhamnosus (LGG) demonstrates potential as an adjunctive treatment for autism spectrum disorder (ASD). In a rat model of ASD induced by lipopolysaccharide (LPS) injection during pregnancy, we evaluated the effects of these probiotics on offspring. Administration of L. reuteri or LGG for three weeks post-birth improved social deficits and reduced anxiety in LPS-exposed rats. Additionally, probiotics significantly modified short-chain fatty acid profiles, increasing butyric acid levels and decreasing propionic acid levels. They also enhanced colonic barrier integrity by upregulating tight junction proteins, including ZO-1, Occludin, and Claudin4. RNA sequencing identified differential gene expression in pathways related to inflammation, the HPA axis, and reactive oxygen species metabolism, with NADPH oxidase 1 (NOX1) emerging as a crucial gene. Validation studies confirmed that Lactobacillus strains reduced inflammatory cytokines, inhibited corticosterone secretion, increased antioxidant levels, and suppressed the NF-κB/NOX1 pathway. In an H2O2-induced oxidative stress model using Caco-2 cells, pre-treatment with L. reuteri, LGG, or NF-κB inhibitors enhanced cellular antioxidants, inhibited NF-κB/NOX1 activation, and improved barrier function. Overall, L. reuteri and LGG administration improved social behavior, bolstered colonic barrier function, and mitigated HPA axis overactivation in LPS-exposed rats, while also alleviating oxidative stress in the colon and Caco-2 cells. These findings suggest that L. reuteri and LGG have substantial clinical potential for ASD treatment by targeting multiple pathophysiological mechanisms, including inflammation, HPA axis dysregulation, and oxidative stress, thereby presenting a promising adjunctive therapeutic strategy for enhancing social behavior and gut health in ASD.

Dietary Additive Combination for Dairy Calves After Weaning Has a Modulating Effect on the Profile of Short-Chain Fatty Acids in the Rumen and Fecal Microbiota

Dietary Additive Combination for Dairy Calves After Weaning Has a Modulating Effect on the Profile of Short-Chain Fatty Acids in the Rumen and Fecal Microbiota

Dietary Dihydroquercetin Alleviated Colitis via the Short-Chain Fatty Acids/miR-10a-5p/PI3K-Akt Signaling Pathway.

Gut microbiota provides an important insight into clarifying the mechanism of active substances with low bioavailability, but its specific action mechanism varied case by case and remained unclear. Dihydroquercetin (DHQ) is a bioactive flavonoid with low bioavailability, which showed beneficial effects on colitis alleviation and gut microbiota modulation. Herein, we aimed to explore the microbiota-dependent anticolitis mechanism of DHQ in sight of gut microbiota metabolites and their interactions with microRNAs (miRNAs). Dietary supplementation of DHQ alleviated dextran sulfate sodium-induced colitis phenotypes and improved gut microbiota dysbiosis. Fecal microbiota transplantation further revealed that the anticolitis activity of DHQ was mediated by gut microbiota. To clarify how the modulated gut microbiota alleviated colitis in mice, the tandem analyses of the microbiome and targeted metabolome were performed, and altered profiles of metabolite short-chain fatty acids (SCFAs) and bile acids and their producers were observed in DHQ-treated mice. In addition, SCFA treatment showed anticolitis activity compared to that of bile acids, along with the specific inhibition on the phosphoinositide-3-kinase (PI3K)-protein kinase B (Akt) pathway. Subsequently, the colonic miRNA profile of mice receiving SCFA treatment was sequenced, and a differentially expressed miR-10a-5p was identified. Both prediction analysis and dual-luciferase reporter assay indicated that miR-10a-5p directly bind to the 3'-untranslated regions of gene pik3ca, inhibit the PI3K-Akt pathway activation, and lead to colitis alleviation. Together, we proposed that gut microbiota mediated the anticolitis activity of DHQ through the SCFAs/miR-10a-5p/PI3K-Akt axis, and it provided a novel insight into clarifying the microbiota-dependent mechanism via the interaction between metabolites and miRNAs.

Metataxonomic and Immunological Analysis of Feces from Children with or without Phelan-McDermid Syndrome.

Phelan-McDermid syndrome (PMS) is a neurodevelopmental disorder characterized by a developmental delay and autism spectrum disorder (ASD)-like behaviors. Emerging research suggests a link between gut microbiota and neuropsychiatric conditions, including PMS. This study aimed to investigate the fecal microbiota and immune profiles of children with PMS compared to healthy controls. Fecal samples were collected from children diagnosed with PMS and age-matched healthy controls. The bacterial composition was analyzed using 16S rRNA gene sequencing, while short-chain fatty acids (SCFAs) were quantified through gas chromatography. Immunological profiling was conducted using a multiplex cytokine assay. Significant differences were observed in the gut microbiota composition between PMS patients and controls, including a lower abundance of key bacterial genera such as Faecalibacterium and Agathobacter in PMS patients. SCFA levels were also reduced in PMS patients. Immunological analysis revealed higher levels of several pro-inflammatory cytokines in the PMS group, although these differences were not statistically significant. The findings indicate that children with PMS have distinct gut microbiota and SCFA profiles, which may contribute to the gastrointestinal and neurodevelopmental symptoms observed in this syndrome. These results suggest potential avenues for microbiota-targeted therapies in PMS.

Integrative microbiomics, proteomics and lipidomics studies unraveled the preventive mechanism of Shouhui Tongbian Capsules on cerebral ischemic stroke injury

Ethnopharmacological relevanceCerebral ischemic stroke (CIS) is one of the most important factors leading to death and disability, which seriously threaten the survival and health of patients. The intentional flora and its derived metabolites are demonstrated to play vital roles in the physiology and onset of CIS. Shouhui Tongbian Capsules (SHTB), a Traditional Chinese Medicine, could regulate gut microbiota and metabolites. Study has found that SHTB has protective effect on CIS, but the mechanism is still unclear. Aim of studyThis study was designed to evaluate the preventive effects and the mechanism of SHTB on CIS injury. Materials and methodsThe rats were pretreated with SHTB for 5 days, then the middle cerebral artery occlusion/reperfusion (MCAO/R) was established. Neurological deficit score, TTC staining, brain water content, H&E and Nissl staining were preformed to evaluate the preventive effects of SHTB on CIS. The Occludin and ZO-1 were analyzed to evaluate the blood-brain barrier (BBB). 16S rDNA sequencing and LC-ESI-MS/MS-based metabolomics profiling were performed to analyze the gut microbiota composition and short chain fatty acids (SCFAs) profile in gut. Serum lipopolysaccharide specific IgA antibody (LPS-SIgA) and diamine oxidase (DAO), as well as colon Claudin 5 and ZO-1 were analyzed to evaluate the intestinal barrier. Proteomics was used to evaluated the proteins profile in brain. Lipidomics were used to evaluate the brain SCFAs as well as medium and long chain fatty acids (MCFAs and LCFAs). Malondialdehyde (MDA), Total Superoxide dismutase (T-SOD), Glutathione (GSH), Glutathione peroxidase (GSH-Px), Catalase (CAT) and reactive oxygen species (ROS) were assayed to evaluate the oxidative stress in brain. Western blot was performed to evaluate the expression of PPARγ, Nrf2, SLC3A2, SCL7A11, GPX4, ACSL4 and LOX. ResultsSHTB prevented rats from MCAO/R injury, which was confirmed by lower cerebral infarct rate, brain water content, neurological deficit score and nissl body loss, and improved brain pathology. Meanwhile, SHTB upregulated the expression of ZO-1 and Occludin to maintain the integrity of BBB. 16S rDNA sequencing and LC-ESI-MS/MS-based targeted metabolomics found that SHTB increased the abundance of gut microbiota, regulated the numbers of intestinal bacteria to increase the production of Acetic acid, Propionic acid, and Butyric acid, as well as decrease the production of Valeric acid and Hexanoic acid in the gut. Meanwhile, SHTB improved the intestinal barrier by upregulating the protein levels of Claudin 5 and ZO-1, which was confirmed by low concentrations of LPS-SIgA and DAO in serum. Multi omics and spearman correlation analysis indicated that SHTB regulated the abundance of Escherichia-Shigella and Lactobacillus to increase Acetic acid, Propionic acid, and Butyric acid to induce the expression of PPARγ, thereby regulating fatty acid metabolism and degradation, improving lipid metabolism disorders, downregulating lipid oxidative stress, inhibiting ferroptosis, and alleviating brain injury. ConclusionThis study confirmed that SHTB improved the disturbance of fatty acid metabolism in brain tissue by regulating gut microbiota and the production of fecal SCFAs to inhibit ferroptosis caused by lipid oxidative stress and prevent CIS injury, which provided a potential candidate drug for the prevention of CIS.

Multi-View Integrative Approach For Imputing Short-Chain Fatty Acids and Identifying Key factors predicting Blood SCFA.

Short-chain fatty acids (SCFAs) are the main metabolites produced by bacterial fermentation of dietary fiber within gastrointestinal tract. SCFAs produced by gut microbiotas (GMs) are absorbed by host, reach bloodstream, and are distributed to different organs, thus influencing host physiology. However, due to the limited budget or the poor sensitivity of instruments, most studies on GMs have incomplete blood SCFA data, limiting our understanding of the metabolic processes within the host. To address this gap, we developed an innovative multi-task multi-view integrative approach (M2AE, Multi-task Multi-View Attentive Encoders), to impute blood SCFA levels using gut metagenomic sequencing (MGS) data, while taking into account the intricate interplay among the gut microbiome, dietary features, and host characteristics, as well as the nuanced nature of SCFA dynamics within the body. Here, each view represents a distinct type of data input (i.e., gut microbiome compositions, dietary features, or host characteristics). Our method jointly explores both view-specific representations and cross-view correlations for effective predictions of SCFAs. We applied M2AE to two in-house datasets, which both include MGS and blood SCFAs profiles, host characteristics, and dietary features from 964 subjects and 171 subjects, respectively. Results from both of two datasets demonstrated that M2AE outperforms traditional regression-based and neural-network based approaches in imputing blood SCFAs. Furthermore, a series of gut bacterial species (e.g., Bacteroides thetaiotaomicron and Clostridium asparagiforme), host characteristics (e.g., race, gender), as well as dietary features (e.g., intake of fruits, pickles) were shown to contribute greatly to imputation of blood SCFAs. These findings demonstrated that GMs, dietary features and host characteristics might contribute to the complex biological processes involved in blood SCFA productions. These might pave the way for a deeper and more nuanced comprehension of how these factors impact human health.

Altered gut microbial profile accompanied by abnormal short chain fatty acid metabolism exacerbates nonalcoholic fatty liver disease progression

Dysregulation of the gut microbiome has associated with the occurrence and progression of non-alcoholic fatty liver disease (NAFLD). To determine the diagnostic capacity of this association, we compared fecal microbiomes across 104 participants including non-NAFLD controls and NAFLD subtypes patients that were distinguished by magnetic resonance imaging. We measured their blood biochemical parameters, 16 S rRNA-based gut microbiota and fecal short-chain fatty acids (SCFAs). Multi-omic analyses revealed that NAFLD patients exhibited specific changes in gut microbiota and fecal SCFAs as compared to non-NAFLD subjects. Four bacterial genera (Faecalibacterium, Subdoligranulum, Haemophilus, and Roseburia) and two fecal SCFAs profiles (acetic acid, and butyric acid) were closely related to NAFLD phenotypes and could accurately distinguish NAFLD patients from healthy non-NAFLD subjects. Twelve genera belonging to Faecalibacterium, Subdoligranulum, Haemophilus, Intestinibacter, Agathobacter, Lachnospiraceae_UCG-004, Roseburia, Butyricicoccus, Actinomycetales_unclassified, [Eubacterium]_ventriosum_group, Rothia, and Rhodococcus were effective to distinguish NAFLD subtypes. Of them, combination of five genera can distinguish effectively mild NAFLD from non-NAFLD with an area under curve (AUC) of 0.84. Seven genera distinguish moderate NAFLD with an AUC of 0.83. Eight genera distinguish severe NAFLD with an AUC of 0.90. In our study, butyric acid distinguished mild-NAFLD from non-NAFLD with AUC value of 0.83. And acetic acid distinguished moderate-NAFLD and severe-NAFLD from non-NAFLD with AUC value of 0.84 and 0.70. In summary, our study and further analysis showed that gut microbiota and fecal SCFAs maybe a method with convenient detection advantages and invasive manner that are not only a good prediction model for early warning of NAFLD occurrence, but also have a strong ability to distinguish NAFLD subtypes.

Unveiling the therapeutic potential and mechanism of inulin in DSS-induced colitis mice

Inulin has been reported to alleviate colitis. In this study, colitis patients' feces were used to simulate fermentation to demonstrate changes in the microbiota profile in the presence of inulin. We found inulin can reshape the gut microbiota profile of colitis patients, especially by altering the abundance of Faecalibacterium and Blautia. Interestingly, the subsequent co-culture with inulin demonstrated that inulin promoted the growth of these two strains of bacteria. The dextran sodium sulfate (DSS)-induced mouse model was used to examine the effect of inulin and its combination with two probiotics on colitis. Results showed that all three treatments can alleviate the clinical symptoms, including weight-losing, colon-shortening, and the Disease Activity Index (DAI) score. Further investigations showed that the administrations regulate colitis mice's pro- and anti-inflammatory cytokines, such as TNF-α, IL-1β, IL-6, IL-10, and IL-17. Also, they alter the relative abundance of Faecalibacterium and Blautia, change the short-chain fatty acids (SCFAs) profile in the cecum and colon, and improve the intestinal barrier; specifically, the intervention increased the expressions of Claudin, Occludin, Zonula Occludens (ZO)-1, and Mucin (MUC)-2 in colonic tissues, thus restoring the colonic tissue structure and morphology of colitis mice. Collectively, our results confirm that inulin can alter the colitis patients' characteristic microbial community, and they can ameliorate experimental colitis by inhibiting the TRL4/MyD88/NF-κB signaling pathway—improving the inflammatory response and enhancing the intestinal barrier. In conclusion, we propose that inulin may hold promise as a functional food therapeutic approach for the treatment of colitis.

Genomic analysis and functional properties of Lactobacillus johnsonii GJ231 isolated from healthy beagles.

Probiotics are one of the management tools to improve the host's healthy microbiota. The positive effects of probiotics on host health are species-specific, so probiotics isolated from host's own gut may be most beneficial. Many of the metabolites (e.g., short-chain fatty acids, bacteriocins, and hydrogen peroxide) produced by Lactobacillus johnsonii have specific inhibitory profiles against invading pathogens. In this study, we isolated L. johnsonii GJ231 from the intestinal tract of healthy female beagles. The genome size of 1.763 M encoded a total of 1,691 predicted genes. Many carbohydrate-active enzymes responsible for carbohydrate degradation and the production of short-chain fatty acids were also predicted. The metabolic profile of short-chain fatty acids in L. johnsonii GJ231 was determined using LC-MS/MS. The bacteriocin-producing gene bacteriocin (lactacin F) in L. johnsonii GJ231 was also predicted. In vitro, experiments demonstrated that GJ231 can thrive in weak acids, 0.3% bile salts, and artificial gastrointestinal fluid models. It was tolerant of to high temperatures up to 70°C, was non- hemolytic, inhibited pathogenic bacteria, and had a high antioxidant capacity. In vivo safety experiments conducted in mice revealed that oral administration of GJ231 not only had no toxic side effect but also increased their antioxidant capacity. In conclusion, combining the above test results, which collectively demonstrate that canine-derived L. johnsonii GJ231 was a non-pathogenic, acid-tolerant and bile-salt-tolerant probiotic strain that inhibits pathogenic bacteria and improves host antioxidant function. This may make it a promising candidate for the development of innovative functional foods for pets.

Comprehensive modulatory effects of whole grain consumption on immune-mediated inflammation in middle-aged and elderly community residents: A real-world randomized controlled trial

Background and aimsWhole grain consumption is widely recognized as a vital component of a balanced diet. Dietary fiber has been well-documented to play a crucial role in these health benefits attributed to whole grain intake. However, population-based evidence directly linking whole grain consumption to anti-inflammatory effects, especially in the context of immune-mediated inflammation, remains limited. We hypothesized that whole grain consumption promotes health by modulating immune-mediated inflammation. Methods and resultsThis study was designed as a real-world, population-based randomized controlled trial. We compared the effects of whole grain versus refined grain consumption on immune-mediated inflammation through staple food substitution, while participants maintained their usual dietary practices. The results demonstrated that whole grain consumption significantly reduced circulating levels of pro-inflammatory cytokines IL-22 and IL-23 compared to refined grain consumption. These reductions were associated with optimized short-chain fatty acid profiles and changes in CD4+ T cell subset distributions. ConclusionsThe findings suggest that the anti-inflammatory effects of whole grain consumption in middle-aged and elderly populations are mediated by targeting specific CD4+ T cell subsets, in addition to modulating both upstream short-chain fatty acid composition and downstream expression of the pro-inflammatory cytokines IL-22 and IL-23.

Two-Year Study on the Intra-Individual Dynamics of Gut Microbiota and Short-Chain Fatty Acids Profiles in Healthy Adults.

While the gut microbiome has been intensively investigated for more than twenty years already, its role in various disorders remains to be unraveled. At the same time, questions about what changes in the gut microbiota can be considered as normal or pathological and whether communities are able to recover after exposure to negative factors (diseases, medications, environmental factors) are still unclear. Here, we describe changes in the gut microbiota composition and the content of short-chain fatty acids in adult healthy volunteers (n = 15) over a 24 month-period. Intraindividual variability in gut microbial composition was 40%, whereas the short chain fatty acids profile remained relatively stable (2-year variability 20%, inter-individual 26%). The changes tend to accumulate over time. Nevertheless, both short-term and long-term changes in the gut microbiome composition were significantly smaller within individuals than interindividual differences (two-year interindividual variability was 75%). Seasonal changes in gut microbiota were found more often in autumn and spring involving the content of minor representatives (less than 1.5% of the community in average) in the phyla Actinobacteriota, Firmicutes and Proteobacteria.

Metabolic Profiles of the Gut Microbiota in Patients with Different Stages of Metabolism Dysfunction-Associated Fatty Liver Disease

Aim: to study the metabolic activity of the intestinal microbiota depending on the stage of metabolic dysfunction-associated fatty liver disease (MAFLD). Materials and methods. The study included 85 patients with MAFLD (27 patients with steatosis without steatohepatitis and fibrosis, 42 patients with steatohepatitis, 16 patients with cirrhosis as an outcome of MAFLD, Child — Pugh class A–B) and 20 healthy people who formed the control group. The level and spectrum of short-chain fatty acids (SCFA) were determined by gas-liquid chromatography. Results. It was found that patients with MAFLD at the stage of steatosis and cirrhosis of the liver have unidirectional changes in the metabolic activity of the intestinal microbiota. We established a decrease in the absolute concentrations of SCFA — their total content, the level of acetate, propionate, butyrate, a decrease in the level of isoacids. The SCFA profiles showed an increase in the proportion of acetate and a decrease in propionate and butyrate. Moreover, changes in the named parameters of SCFAs are aggravated with progression to liver cirrhosis. At the stage of steatohepatitis, we identified two subgroups of patients with different levels of metabolic activity of the microbiota. Patients whose microbiota metabolism for SCFA production was high had correspondingly elevated SCFA levels. And, on the contrary, patients in whom the metabolic activity of the microbiota was reduced were characterized by a steady decrease in SCFAs and disease progression to liver cirrhosis. In the study, we showed an inverse correlation between the calculated prognostic indices of NFS and FIB-4, elastography values with the total level of SCFA, the level of acetate, propionate, butyrate. Thus, a decrease in the content of SCFA for patients with MAFLD can be considered as a prognostic marker of an unfavorable course of liver disease.