Ficus pandurata Hance Inhibits Ulcerative Colitis and Colitis-Associated Secondary Liver Damage of Mice by Enhancing Antioxidation Activity

Study on the Protective Effect and Mechanism of Umbilicaria esculenta Polysaccharide in DSS-Induced Mice Colitis and Secondary Liver Injury

This study aimed to explore the ameliorative effects and potential mechanisms of Huangshan Umbilicaria esculenta polysaccharide (UEP) in dextran sulfate sodium-induced acute ulcerative colitis (UC) and UC secondary liver injury (SLI). Results showed that UEP could ameliorate both colon and liver pathologic injuries, upregulate mouse intestinal tight junction proteins (TJs) and MUC2 expression, and reduce LPS exposure, thereby attenuating the effects of the gut-liver axis. Importantly, UEP significantly downregulated the secretion levels of TNF-α, IL-1β, and IL-6 through inhibition of the NF-κB pathway and activated the Nrf2 signaling pathway to increase the expression levels of SOD and GSH-Px. In vitro, UEP inhibited the LPS-induced phosphorylation of NF-κB P65 and promoted nuclear translocation of Nrf2 in RAW264.7 cells. These results revealed that UEP ameliorated UC and SLI through NF-κB and Nrf2-mediated inflammation and oxidative stress. The study first investigated the anticolitis effect of UEP, suggesting its potential for the treatment of colitis and colitis-associated liver disease.

Sirtuin 3 ameliorates inflammatory bowel disease via inhibiting intestinal inflammation and oxidative stress

Sirtuin 3 involved in development of various diseases, but its role in inflammatory bowel disease is still unknown. We used inflammatory bowel disease biopsies, colitis animal model, and vitro cells RAW264.7 to study the role of Sirtuin 3 in the pathophysiology of inflammatory bowel disease. Sirtuin 3 negatively correlated with intestinal TNF-α. Sirt3 was less pronounced in pediatric and adult inflammatory bowel disease patients compared with corresponding control group. Sirtuin 3 activator Honokiol suppressed dextran sulfate sodium induced colonic manifestations, while Sirt3 inhibitor caused opposite results. Honokiol inhibited colonic oxidative stress by and reduced intestinal permeability. Honokiol repressed inflammatory response by reducing macrophage infiltration, pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 levels, and inhibiting activation of NF-κB p65 in the colitis mice. However, Sirt3 inhibitor amplified colonic oxidative stress and inflammatory response. In vitro study, Sirt3 inhibitor or siRNA Sirtuin 3 activated NF-κB p65 and enhanced TNF-α, IL-1β, and IL-6 secretion from LPS stimulated RAW264.7, while Honokiol remarkably attenuated these pro-inflammatory cytokines secretion. Finally, knockdown of Sirt3 in Caco-2 cells enhanced TNF-α induced intestinal barrier integrity injury. Sirtuin 3 negatively regulates inflammatory bowel disease progression via reducing colonic inflammation and oxidative stress. Sirtuin 3 is a promising therapeutic target in clinical application for inflammatory bowel disease therapy.

Effects of soyhulls with different particle size on the growth performance, blood indices and gut microbiota of yellow feather broilers

1. The objective of this study was to determine the effects of soyhulls with different particle sizes on the growth performance, blood indices and gut microbiota of yellow feather broilers.2. Total of 240 healthy, one-day-old, yellow feather broilers were randomly divided into four groups, with six pen replicates within each group and ten birds per pen. The control group birds were fed the basal diet (Control). For the treatment groups, 5% soyhulls with different particle sizes were included in the basal diet. The particle size geometric mean diameters (dgw) of the soyhulls in the three treatment groups were 299.69 μm (LowPS), 489.85 μm (MediumPS) and 734.83 μm (HighPS) with geometric standard deviation (Sgw) 1.75 μm, 1.62 μm and 1.67 μm, respectively.3. Results showed that the growth performance variables and organ indices were not different among the four groups. The MediumPS group had increased TG, T-CHO, ALT, HDL-C, and GSH-PX levels and decreased T-AOC levels, whereas LowPS and HighPS groups had increased HDL-C and GSH-PX levels (p < 0.05). Microbial diversity analysis showed that the intestinal microbiota of yellow feather broilers mainly included Firmicutes and Bacteroidetes. Inclusion of 5% soyhulls with different particle size had no effect on alpha diversity indices of caecal microbiota. The HighPS group had significantly higher relative abundance of Firmicutes spp. and lower Bacteroidetes spp. compared with the LowPS and MediumPS group but this was not different from the Control group. The relative abundance of Cyanobacteria spp. was significantly higher in the HighPS group than the other three groups. LEfSe analysis showed that there were more enriched biomarker taxa in the groups with soyhulls than the control group.4. Overall, the inclusion of soyhulls with different particle sizes had limited effects on growth performance, blood indices and caecal microbiota composition of yellow feather broilers.

Wuling capsule modulates macrophage polarization by inhibiting the TLR4-NF-κB signaling pathway to relieve liver fibrosis

BACKGROUND AND PURPOSE

Wuling capsule (WL) has good efficacy in the clinical treatment of chronic hepatitis B and liver injury. Liver fibrosis is a common pathological feature of chronic liver disease and may progress to irreversible cirrhosis and liver cancer. Accumulating evidence reveals that modulating macrophage polarization contribute to the therapy of liver fibrosis. However, the effects of WL on modulating macrophage polarization to relive liver fibrosis remain unclear. This study investigated the anti-liver fibrosis effects of WL in carbon tetrachloride (CCl4)-induced liver fibrosis in rats, and the modulation effects and underlying molecular mechanism on macrophage polarization.

METHODS

A rat liver fibrosis model was constructed by intraperitoneal injection of 40 % CCl4 olive oil mixture. At 2, 4, 6, and 8 weeks, the histopathological status of the liver was assessed by hematoxylin-eosin (HE) and Masson staining; the liver biochemical indexes were measured in rat liver tissue. The expression levels of inflammatory cytokines in liver tissue were detected by ELISA. The mRNA levels and proteins expression of macrophage markers of different phenotypes, TLR4-NF-κB signaling pathway indicators were detected independently by ELISA, immunofluorescence, RT-PCR and western blotting.

RESULTS

In vivo, WL treatment attenuated abnormal changes in weight, organ indices and biochemical indices, alleviated pathological changes, and reduced collagen fiber deposition as well as the expression of α-SMA in liver tissues. Further studies revealed that WL decreased the expression of the macrophage M1 polarization markers inducible nitric oxide synthase (iNOS), TNF-α, IL-6, and CD86, promoted the expression of the M2 macrophage polarization markers IL-10, CD206, and arginase-1 (Arg-1), and inhibited the activation of the TLR4-NF-κB signaling pathway via several key signaling proteins. In vitro, WL significantly suppressed macrophage M1 polarization, and promoted M2 polarization while boosted M1 polarization transform to M2 polarization in LPS-activated RAW264.7 cells.

CONCLUSIONS

This study demonstrated that WL modulated macrophage polarization against liver fibrosis mainly by inhibiting the activation of the TLR4-NF-κB signaling pathway.

Rosa Roxburghii Tratt Fruit Extract Prevents Dss-Induced Ulcerative Colitis in Mice by Modulating the Gut Microbiota and the IL-17 Signaling Pathway

Ulcerative colitis (UC) is a non-specific inflammatory bowel illness characterized by intestinal mucosal barrier degradation, inflammation, oxidative damage, and gut microbiota imbalances. Rosa roxburghii Tratt Fruit extract (RRTE) was extracted from Rosa roxburghii Tratt fruit, exhibiting an excellent prevention effect against UC; RRTE could prevent the damage of DSS-induced human normal colonic epithelial (NCM 460) cells, especially in cell viability and morphology, and oxidative damage. Additionally, in UC mice, RRTE could limit the intestinal mucosal barrier by increasing the expression of intestinal tight junction proteins and mucin, reducing inflammation and oxidative damage in colon tissue. More importantly, RRTE can increase the abundance of beneficial bacteria to regulate gut microbiota such as Ruminococcus, Turicibacter, and Parabacteroides, and reduce the abundance of harmful bacteria such as Staphylococcus and Shigella. Furthermore, transcriptomics of colonic mucosal findings point out that the beneficial effect of RRTE on UC could be attributed to the modulation of inflammatory responses such as the IL-17 and TNF signaling pathways. The qPCR results confirm that RRTE did involve the regulation of several genes in the IL-17 signaling pathway. In conclusion, RRTE could prevent DSS-induced damage both in vitro and in vivo.

Mesalazine hollow suppositories based on 3D printing for treatment of ulcerative colitis

Mesalazine (MSZ) suppositories are a first-line medication for the localized treatment of ulcerative colitis (UC). However, the frequent defecation of patients with UC influences the retention of the suppository in the rectum and multiple doses have to be applied. Here, a mesalazine hollow suppository (MHS) is developed using three-dimensional (3D) printing. The MHS is composed of an inner supporting spring and an outer MSZ-loaded curved hollow shell. Springs were prepared using fused deposition modeling (FDM) 3D printing with thermoplastic urethane filaments, followed by splitting. The optimal parameters, including elasticity, filament diameter, spring inner diameter, and filament distance, were screened. The shell was prepared by FDM 3D printing utilizing MSZ, polyvinyl alcohol, and polyethylene glycol, which were assembled with springs to obtain FDM 3D-printed MHS (F-MHS); if 3D-printed metal molding was used in preparing shell, mold-formed MHS (M-MHS) was obtained. The F-MHS exhibited faster MSZ release than the M-MHS; therefore, the molding method is preferable. The inserted M-MHS was retained in the rat rectum for 5 h without affecting defecation. M-MHS alleviated tissue damage of UC rats and reduced inflammation with low levels of myeloperoxidase and proinflammatory cytokines. Personalized MHS is a promising medication for the localized treatment of UC.

Medicinal Plants, Phytochemicals and Regulation of the NLRP3 Inflammasome in Inflammatory Bowel Diseases: A Comprehensive Review

Ongoing research explores the underlying causes of ulcerative colitis and Crohn's disease. Many experts suggest that dysbiosis in the gut microbiota and genetic, immunological, and environmental factors play significant roles. The term "microbiota" pertains to the collective community of microorganisms, including bacteria, viruses, and fungi, that reside within the gastrointestinal tract, with a particular emphasis on the colon. When there is an imbalance or disruption in the composition of the gut microbiota, it is referred to as dysbiosis. Dysbiosis can trigger inflammation in the intestinal cells and disrupt the innate immune system, leading to oxidative stress, redox signaling, electrophilic stress, and inflammation. The Nod-like Receptor (NLR) Family Pyrin Domain Containing 3 (NLRP3) inflammasome, a key regulator found in immunological and epithelial cells, is crucial in inducing inflammatory diseases, promoting immune responses to the gut microbiota, and regulating the integrity of the intestinal epithelium. Its downstream effectors include caspase-1 and interleukin (IL)-1β. The present study investigated the therapeutic potential of 13 medicinal plants, such as Litsea cubeba, Artemisia anomala, Piper nigrum, Morus macroura, and Agrimonia pilosa, and 29 phytocompounds such as artemisitene, morroniside, protopine, ferulic acid, quercetin, picroside II, and hydroxytyrosol on in vitro and in vivo models of inflammatory bowel diseases (IBD), with a focus on their effects on the NLRP3 inflammasome. The observed effects of these treatments included reductions in IL-1β, tumor necrosis factor-alpha, IL-6, interferon-gamma, and caspase levels, and increased expression of antioxidant enzymes, IL-4, and IL-10, as well as regulation of gut microbiota. These effects could potentially provide substantial advantages in treating IBD with few or no adverse effects as caused by synthetic anti-inflammatory and immunomodulated drugs. However, additional research is necessary to validate these findings clinically and to develop effective treatments that can benefit individuals who suffer from these diseases.

Nogo-B inhibition restricts ulcerative colitis via inhibiting p68/miR-155 signaling pathway

BACKGROUND & AIMS

Ulcerative colitis (UC) is a main type of inflammatory bowel diseases which spreads globally during the westernization of lifestyle over the past few decades. However, the cause of UC is still not fully understood. We aimed to disclose the role of Nogo-B in the development of UC.

METHODS

Nogo-deficiency (Nogo^-/-) and wild-type male mice were treated with dextran sodium sulfate (DSS) to conduct a UC model, followed by determination of colon and serum inflammatory cytokines level. RAW264.7, THP1 and NCM460 cells were used to determine macrophage inflammation as well as proliferation and migration of NCM460 cells under Nogo-B or miR-155 intervention.

RESULTS

Nogo deficiency significantly reduced DSS-induced weight loss, colon length and weight reduction, and inflammatory cells accumulation in the intestinal villus, while increased the expression of tight junctions (TJs) proteins (Zonula occludens-1, Occludin) and adherent junctions (AJs) proteins (E-cadherin, α-catenin), implying that Nogo deficiency attenuated DSS-induced UC. Mechanistically, Nogo-B deficiency reduced TNFα, IL-1β and IL-6 levels in the colon, serum, RAW264.7 cells and THP1-derived macrophages. Furthermore, we identified that Nogo-B inhibition can reduce the maturation of miR-155, which is essential for Nogo-B-affected inflammatory cytokines expression. Interestingly, we determined that Nogo-B and p68 can interact with each other to promote the expression and activation of Nogo-B and p68, thus facilitating miR-155 maturation to induce macrophage inflammation. Blocking p68 inhibited Nogo-B, miR-155, TNFα, IL-1β and IL-6 expression. Moreover, the culture medium collected from Nogo-B overexpressed macrophages can inhibit enterocytes NCM460 cells proliferation and migration.

CONCLUSION

We disclose that Nogo deficiency reduced DSS-induced UC via inhibiting p68-miR-155-activated inflammation. Our results indicate that Nogo-B inhibition serves as a new potential therapeutic candidate for the prevention and treatment of UC.

Progress on Regulation of NLRP3 Inflammasome by Chinese Medicine in Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is a chronic, non-specific intestinal disease that not only affects the quality of life of patients and their families but also increases the risk of colorectal cancer. The nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome is an important component of inflammatory response system, and its activation induces an inflammatory cascade response that is involved in the development and progression of UC by releasing inflammatory cytokines, damaging intestinal epithelial cells, and disrupting the intestinal mucosal barrier. Chinese medicine (CM) plays a vital role in the prevention and treatment of UC and is able to regulate NLRP3 inflammasome. Many experimental studies on the regulation of NLRP3 inflammasome mediated by CM have been carried out, demonstrating that CM formulae with main effects of clearing heat, detoxifying toxicity, drying dampness, and activating blood circulation. Flavonoids and phenylpropanoids can effectively regulate NLRP3 inflammasome. Other active components of CM can interfere with the process of NLRP3 inflammasome assembly and activation, leading to a reduction in inflammation and UC symptoms. However, the reports are relatively scattered and lack systematic reviews. This paper reviews the latest findings regarding the NLRP3 inflammasome activation-related pathways associated with UC and the potential of CM in treating UC through modulation of NLRP3 inflammasome. The purpose of this review is to explore the possible pathological mechanisms of UC and suggest new directions for development of therapeutic tools.

Liver Protection of a Low-Polarity Fraction from Ficus pandurata Hance, Prepared by Supercritical CO2 Fluid Extraction, on CCl4-Induced Acute Liver Injury in Mice via Inhibiting Apoptosis and Ferroptosis Mediated by Strengthened Antioxidation

Ficus pandurata Hance (FPH) is a Chinese herbal medicine widely used for health care. This study was designed to investigate the alleviation efficacy of the low-polarity ingredients of FPH (FPHLP), prepared by supercritical CO₂ fluid extraction technology, against CCl₄-induced acute liver injury (ALI) in mice and uncover its underlying mechanism. The results showed that FPHLP had a good antioxidative effect determined by the DPPH free radical scavenging activity test and T-AOC assay. The in vivo study showed that FPHLP dose-dependently protected against liver damage via detection of ALT, AST, and LDH levels and changes in liver histopathology. The antioxidative stress properties of FPHLP suppressed ALI by increasing levels of GSH, Nrf2, HO-1, and Trx-1 and reducing levels of ROS and MDA and the expression of Keap1. FPHLP significantly reduced the level of Fe²⁺ and expression of TfR1, xCT/SLC7A11, and Bcl2, while increasing the expression of GPX4, FTH1, cleaved PARP, Bax, and cleaved caspase 3. The results demonstrated that FPHLP protected mouse liver from injury induced by CCl₄ via suppression of apoptosis and ferroptosis. This study suggests that FPHLP can be used for liver damage protection in humans, which strongly supports its traditional use as a herbal medicine.

Effects of Medicinal Plants and Phytochemicals in Nrf2 Pathways during Inflammatory Bowel Diseases and Related Colorectal Cancer: A Comprehensive Review

Inflammatory bowel diseases (IBDs) are related to nuclear factor erythroid 2-related factor 2 (Nrf2) dysregulation. In vitro and in vivo studies using phytocompounds as modulators of the Nrf2 signaling in IBD have already been published. However, no existing review emphasizes the whole scenario for the potential of plants and phytocompounds as regulators of Nrf2 in IBD models and colitis-associated colorectal carcinogenesis. For these reasons, this study aimed to build a review that could fill this void. The PubMed, EMBASE, COCHRANE, and Google Scholar databases were searched. The literature review showed that medicinal plants and phytochemicals regulated the Nrf2 on IBD and IBD-associated colorectal cancer by amplifying the expression of the Nrf2-mediated phase II detoxifying enzymes and diminishing NF-κB-related inflammation. These effects improve the bowel environment, mucosal barrier, colon, and crypt disruption, reduce ulceration and microbial translocation, and consequently, reduce the disease activity index (DAI). Moreover, the modulation of Nrf2 can regulate various genes involved in cellular redox, protein degradation, DNA repair, xenobiotic metabolism, and apoptosis, contributing to the prevention of colorectal cancer.

Xianglian Pill attenuates ulcerative colitis through TLR4/MyD88/NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Xianglian Pill (XLP) is a classical Chinese medicine prescription applied for controlling ulcerative colitis (UC). Whereas, the underlying mechanism remains unclear.

AIM OF THE STUDY

The present work was aimed to investigate the mechanism of XLP in dextran sulfate sodium (DSS)-induced UC via the Toll Like Receptor 4 (TLR4)/Myeloid Differentiation factor 88 (MyD88)/Nuclear Factor kappa-B (NF-κB) signaling in mice.

MATERIALS AND METHODS

The major components of XLP were detected by high-performance liquid chromatography-diode array detection (HPLC-DAD). The ulcerative colitis model was induced by DSS in mice. 5-Amino Salicylic Acid (5-ASA) group and XLP group were intragastrically treated. Disease activity index (DAI) and colon length were monitored and hematoxylin-eosin (HE) staining was conducted. Gasdermin D (GSDMD)-N and TLR4 expressions in colon tissues were visualized by immunofluorescence. TLR4 mRNA was measured by Real Time Quantitative PCR (RT-qPCR). The expressions of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), active-caspase-1, GSDMD-N, TLR4, MYD88, NF-κB, p-NF-κB, and the ubiquitination of TLR4 in colon tissues were detected by Western blot. Myeloperoxidase (MPO) enzyme activity was examined and serum inflammatory factors Interleukin (IL)-1β, IL-6, Tumor Necrosis Factor-α (TNF-α), and IL-18 were determined by Enzyme-linked Immunosorbent Assay (ELISA). TLR4^-/- mice were applied for verifying the mechanism of XLP attenuated DSS symptoms.

RESULTS

The XLP treatment extended colon length, reduced DAI, and attenuated histopathological alteration in DSS-induced mice. XLP administration suppressed MPO activity and reduced the content of IL-1β, IL-6, TNF-α and IL-18 in serum. XLP also inhibited the expression levels of GSDMD-N, TLR4, NLRP3, active-caspase-1, MyD88, p-NF-κB/NF-κB in colon tissues of DSS-induced mice. TLR4^-/- mice proved that TLR4 was involved in XLP-mediated beneficial effect on DSS-induced ulcerative colitis.

CONCLUSIONS

XLP might treat ulcerative colitis by regulating the TLR4/MyD88/NF-κB signaling pathway.

Polysaccharides from Garlic Protect against Liver Injury in DSS-Induced Inflammatory Bowel Disease of Mice via Suppressing Pyroptosis and Oxidative Damage

Inflammatory bowel disease (IBD), a widespread intestinal disease threatening human health, is commonly accompanied by secondary liver injury (SLI). Pyroptosis and oxidative stress act as an important role underlying the pathophysiology of SLI, during which a large number of proinflammatory cytokines and oxidative intermediates can be produced, thereby causing the liver severely damaged. Suppression of pyroptosis and oxidative damage can be considered one of the critical strategies for SLI therapy. Garlic, a natural food with eatable and medicinal functions, is widely used in people's daily life. There is no study about the alleviation of garlic against IBD accompanied with SLI. This study is aimed at investigating the efficacy of the polysaccharides from garlic (PSG) in treating IBD and SLI, as well as its pharmacological mechanism. The results showed that PSG significantly alleviated dextran sulfate sodium-induced IBD determined by evaluating the bodyweight loss, disease activity index, colon length, and colonic pathological examination of mice. PSG significantly reduced the colonic inflammation by reversing the levels of myeloperoxidase, diamine oxidase activity, iNOS, and COX2 and strengthened the intestinal barrier by increasing the expressions of ZO1, occludin, and MUC2 of IBD mice. Furthermore, PSG strongly alleviated SLI determined by assessing the liver morphological change, liver index, levels of ALT and AST, and liver pathological change of mice. Mechanically, PSG reduced the high levels of LPS, IL-1β, IL18, NLRP3, gasdermin D, caspase 1, ASC, TLR4, MyD88, NF-κB, phospho-NF-κB, while it increased IL-10 in the livers of mice, indicating that PSG alleviated SLI by suppressing inflammation and pyroptosis. Additionally, PSG significantly inhibited the oxidative damage in the liver tissues of SLI mice by reducing the levels of ROS, MDA, Keap-1, 8-OHDG, and phospho-H2AX and increasing the levels of GPX4, SOD2, HO1, NQO1, and Nrf2. These findings suggested that the garlic polysaccharides could be used to treat IBD accompanied with SLI in humans.

Andrographolide sodium bisulfite ameliorates dextran sulfate sodium-induced colitis and liver injury in mice via inhibiting macrophage proinflammatory polarization from the gut-liver axis

Ulcerative colitis (UC), an inflammatory disease, is widely thought to be associated with colonic barrier damage and inflammatory response. With the destruction of the colonic barrier, lipopolysaccharide (LPS) enters the liver through the portal vein and causes liver injury. Liver injury in turn exacerbates UC to form a vicious cycle, so the treatment of liver injury cannot be ignored. Andrographolide (Andro) has a protective effect against colitis and liver injury, but with low bioavailability. Andrographolide sodium bisulfite (ASB), a water-soluble sulfonate of Andro, has better bioavailability, whether it has a better curative effect against UC and liver injury is rarely reported. Hence, we investigated the protective effect and potential mechanism of ASB against dextran sulfate sodium (DSS)-induced UC and liver injury in mice. The results showed that treatment with ASB significantly relieved the clinical symptoms of UC and liver injury by reducing disease activity index, inhibiting gut-derived LPS leakage, and improving colonic and hepatic injury, and its curative effect was better than Andro. Moreover, ASB effectively decreased the YAP-mediated colonic inflammation and TLR4/MyD88/NF-κB-mediated pro-inflammatory factor release in the liver. Both colonic and hepatic inflammation were associated with macrophage proinflammatory polarization, but they were significantly inhibited by ASB. ASB showed good safety in the treatment of UC and liver injury and has no nephrotoxicity as previously described. In conclusion, ASB has an effective protective effect on DSS-induced UC and liver injury, mainly by suppressing macrophage proinflammatory polarization from the gut-liver axis.

Multi-omic Profiling Reveals that Intra-abdominal-Hypertension-Induced Intestinal Damage Can Be Prevented by Microbiome and Metabolic Modulations with 5-Hydroxyindoleacetic Acid as a Diagnostic Marker

Emerging evidence shows that modulation of the microbiome can suppress intra-abdominal hypertension (IAH)-induced intestinal barrier damage through the regulation of amino acid (AA) biosynthesis. Here, we investigated the protective effects of orally gavaged Lactobacillus acidophilus L-92 (L92) and a mixture of AA in rats with induced IAH. The results showed that both L92 and AA pretreatments effectively mitigated IAH-induced intestinal damage. Interestingly, L92 but not AA prevented metagenomic changes induced by IAH. Bacteroides fragilis, Bacteroides eggerthii, Bacteroides ovatus, Faecalibacterium prausnitzii, Prevotella, and extensively altered functional pathways were associated with L92-mediated host protection. Metabolomic profiling revealed that tryptophan metabolism was involved in both L92- and AA-mediated gut protection. The tryptophan metabolite 5-hydroxyindoleacetic acid (5-HIAA) is a sensitive biomarker for IAH in rats and patients with either gut-derived sepsis (n = 41) or all-source sepsis (n = 293). In conclusion, we show that microbiome and metabolic modulations can effectively prevent IAH-induced intestinal damage and that 5-HIAA is a potential metabolic marker for IAH and sepsis.

IMPORTANCE Gut protection through modulation of the microbiome for critically ill patients has been gaining much attention recently. Intra-abdominal hypertension (IAH) is a prevailing clinical feature of acute gastrointestinal injuries in critically ill patients, characterized by nonspecific intestinal barrier damage. Prolonged IAH can induce or aggravate the development of sepsis and multiorgan dysfunctions. Therefore, the prevention of IAH-induced damage in rats through microbiome and metabolic interventions by commercially available L92 and AA treatments and the identification of 5-HIAA as an important marker for IAH/sepsis have important clinical implications for the treatment and early diagnosis of critically ill patients.