L. reuteri ZJ617 inhibits inflammatory and autophagy signaling pathways in gut-liver axis in piglet induced by lipopolysaccharide

Lactobacillus reuteri ZJ617 attenuates metabolic syndrome via microbiota-derived spermidine

Metabolic syndrome (MetS) is a difficult-to-manage disease that poses a significant risk to human health. Here, we show that the supplementation of Lactobacillus reuteri ZJ617 ameliorates symptoms of MetS in mice induced by the high-fat diet. L. reuteri ZJ617 modulates host metabolism by interacting with the microbiome, resulting in the production of spermidine synthesized by the microbiota. L. reuteri ZJ617 serves as a source of substrates for the microbiota to synthesize spermidine, hence preventing the decline of bacteria responsible for spermidine production. Spermidine treatment mimics the metabolic effects of L. reuteri ZJ617, whereas pharmacological inhibition of spermidine biosynthesis in mice abolishes these benefits. Our findings reveal the mechanism by which L. reuteri ZJ617 alleviates MetS symptoms and provide support for its potential use as a probiotic for promoting metabolic health.

Bacillus amyloliquefaciens SC06 Attenuated Lipopolysaccharide-Induced acute liver injury by suppressing bile acid-associated NLRP3 inflammasome activation

The involvement of the inflammatory response has been linked to the development of liver illnesses. As medications with the potential to prevent and cure liver illness, probiotics have garnered an increasing amount of interest in recent years. The present study used a piglet model with acute liver injury (ALI) induced by lipopolysaccharides (LPS) to investigate the regulatory mechanisms of Bacillus amyloliquefaciens SC06. Our findings indicated that SC06 mitigated the liver structural damage caused by LPS, as shown by the decreased infiltration of inflammatory cells and the enhanced structural integrity. In addition, After the administration of SC06, there was a reduction in the increased levels of the liver damage markers. In the LPS group, there was an increase in the mRNA expression of inflammatory cytokines, apoptosis cell rate, and genes associated with apoptosis, while these alterations were mitigated by SC06 administration. Furthermore, SC06 prevented pigs from suffering liver damage by preventing the activation of the NLRP3 inflammasome, which was normally triggered by LPS. The examination of serum metabolic pathways found that ALI was related to several metabolic processes, including primary bile acid biosynthesis, pentose and glucuronate interconversions and the metabolism of phenylalanine. Significantly, our research revealed that the administration of SC06 effectively controlled the concentrations of bile acids in the serum. The correlation results also revealed clear relationships between bile acids and liver characteristics and NLRP3 inflammasome-related genes. However, in vitro experiments revealed that SC06 could not directly inhibit NLRP3 activation under ATP, monosodium urate, and nigericin stimulation, while taurochenodeoxycholic acid (TCDCA) activated NLRP3 inflammasome related genes. In conclusion, our study proved that the hepaprotective effect of SC06 on liver injury, which was closely associated with the restoration of bile acids homeostasis and NLRP3 inflammasome inhibition.

Liensinine alleviates sepsis-induced acute liver injury by inhibiting the NF-κB and MAPK pathways in an Nrf2-dependent manner

Sepsis remains a serious public health issue that needs to be addressed globally. Severe liver injury caused by sepsis increases the risk of death in patients with sepsis. Liensinine (Lie) is one of the primary active components in Plumula nelumbinis and has anti-inflammatory and antioxidant effects. Nevertheless, the effects of Lie on septic liver injury are unclear. This research investigated the protective effect of Lie (10, 20 and 40 mg/kg) on liver damage via intraperitoneal administration of LPS (10 mg/kg) to C57BL/6 mice. Lie was given through intraperitoneal injection once a day for five days. Mice were treated with LPS intraperitoneally for 6 h at 1 h after Lie administration on the last day. The results suggested that Lie could decrease AST and ALT levels in serum, ameliorate histopathological changes and inhibit cell apoptosis in mice with LPS-induced septic liver injury. In addition, Lie inhibited increases in the mRNA levels of TNF-α, IL-1β, iNOS and IL-6. Lie also increased the mRNA level of IL-10. Lie reduced the content of MDA, a marker of lipid peroxidation, and increased the activity of the antioxidant enzymes GSH-Px, CAT and SOD. Our results also showed that Lie could suppress the LPS-activated MAPK and NF-κB pathways and trigger the Nrf2 signaling pathway both in vitro and in vivo. Additionally, an Nrf2 inhibitor (ML385) weakened the suppressive effect of Lie on the MAPK and NF-κB pathways. Our results demonstrated that the suppressive effect of Lie on the MAPK and NF-κB pathways was partially reliant on activation of the Nrf2 pathway. In summary, these results indicate that Lie can improve inflammation and oxidative stress by activating Nrf2, which is a prospective therapeutic drug for alleviating septic liver injury.

Lactobacillus reuteri mitigates hepatic ischemia/reperfusion injury by modulating gut microbiota and metabolism through the Nrf2/HO-1 signaling

BACKGROUND

This study seeks to investigate the impacts of Lactobacillus reuteri (L. reuteri) on hepatic ischemia-reperfusion (I/R) injury and uncover the mechanisms involved.

METHODS

Mice in the I/R groups were orally administered low and high doses of L.reuteri (L.reuteri-low and L. reuteri-hi; 1 × 1010 CFU/d and 1 × 1011 CFU/d), for 4 weeks prior to surgery. Following this, mice in the model group were treated with an Nrf2 inhibitor (ML-385), palmitoylcarnitine, or a combination of both.

RESULTS

After treatment with L. reuteri, mice exhibited reduced levels of serum aminotransferase (ALT), aspartate aminotransferase (AST), and myeloperoxidase (MPO) activity, as well as a lower Suzuki score and apoptosis rate. L. reuteri effectively reversed the I/R-induced decrease in Bcl2 expression, and the significant increases in the levels of Bax, cleaved-Caspase3, p-p65/p65, p-IκB/IκB, p-p38/p38, p-JNK/JNK, and p-ERK/ERK. Furthermore, the administration of L. reuteri markedly reduced the inflammatory response and oxidative stress triggered by I/R. This treatment also facilitated the activation of the Nrf2/HO-1 pathway. L. reuteri effectively counteracted the decrease in levels of beneficial gut microbiota species (such as Blautia, Lachnospiraceae NK4A136, and Muribaculum) and metabolites (including palmitoylcarnitine) induced by I/R. Likewise, the introduction of exogenous palmitoylcarnitine demonstrated a beneficial impact in mitigating hepatic injury induced by I/R. However, when ML-385 was administered prior to palmitoylcarnitine treatment, the previously observed effects were reversed.

CONCLUSION

L. reuteri exerts protective effects against I/R-induced hepatic injury, and its mechanism may be related to the promotion of probiotic enrichment, differential metabolite homeostasis, and the Nrf2/HO-1 pathway, laying the foundation for future clinical applications.

Dietary supplementation of benzoic acid and essential oils combination enhances intestinal resilience against LPS stimulation in weaned piglets

BACKGROUND

The benefits of combining benzoic acid and essential oils (BAO) to mitigate intestinal impairment during the weaning process have been well established, while the detailed underlying mechanism has not been fully elucidated. Previous research has primarily focused on the reparative effects of BAO on intestinal injury, while neglecting its potential in enhancing intestinal stress resistance.

METHODS

In this study, we investigated the pre-protective effect of BAO against LPS-induced stress using a modified experimental procedure. Piglets were pre-supplemented with BAO for 14 d, followed by a challenge with LPS or saline to collect blood and intestinal samples.

RESULTS

Our findings demonstrated that BAO supplementation led to significant improvements in piglets' final weight, average daily gain, and feed intake/body gain ratio. Additionally, BAO supplementation positively influenced the composition of intestinal microbiota, increasing beneficial Actinobacteriota and Alloprevotella while reducing harmful Desulfobacterota, Prevotella and Oscillospira. Furthermore, BAO supplementation effectively mitigated oxidative disturbances and inflammatory responses induced by acute LPS challenge. This was evidenced by elevated levels of T-AOC, SOD, and GSH, as well as decreased levels of MDA, TNF-α, and IL-6 in the plasma. Moreover, piglets subjected to LPS challenge and pre-supplemented with BAO exhibited significant improvements in intestinal morphological structure and enhanced integrity, as indicated by restored expression levels of Occludin and Claudin-1 compared to the non-supplemented counterparts. Further analysis revealed that BAO supplementation enhanced the jejunal antioxidative capacity by increasing GSH-Px levels and decreasing MDA levels under the LPS challenge and stimulated the activation of the Nrf2 signaling pathway. Additionally, the reduction of TLR4/NF-κB/MAPK signaling pathways activation and proinflammatory factor were also observed in the jejunal of those piglets fed with BAO.

CONCLUSIONS

In summary, our study demonstrates that pre-supplementation of BAO enhances the anti-stress capacity of weaned piglets by improving intestinal microbiota composition, reinforcing the intestinal barrier, and enhancing antioxidative and anti-inflammatory capabilities. These effects are closely associated with the activation of Nrf2 and TLR4/NF-κB/MAPK signaling pathways.

Lactobacillus plantarum Metabolites Elicit Anticancer Effects by Inhibiting Autophagy-Related Responses

Lactobacillus plantarum (L. plantarum) is a probiotic that has emerged as novel therapeutic agents for managing various diseases, such as cancer, atopic dermatitis, inflammatory bowel disease, and infections. In this study, we investigated the potential mechanisms underlying the anticancer effect of the metabolites of L. plantarum. We cultured L. plantarum cells to obtain their metabolites, created several dilutions, and used these solutions to treat human colonic Caco-2 cells. Our results showed a 10% dilution of L. plantarum metabolites decreased cell viability and reduced the expression of autophagy-related proteins. Moreover, we found co-treatment with L. plantarum metabolites and chloroquine, a known autophagy inhibitor, had a synergistic effect on cytotoxicity and downregulation of autophagy-related protein expression. In conclusion, we showed the metabolites from the probiotic, L. plantarum, work synergistically with chloroquine in killing Caco-2 cells and downregulating the expression of autophagy-related proteins, suggesting the involvement of autophagy, rather than apoptosis, in their cytotoxic effect. Hence, this study provides new insights into new therapeutic methods via inhibiting autophagy.

Identification of a Novel Strain Lactobacillus Reuteri and Anti-Obesity Effect through Metabolite Indole-3-Carboxaldehyde in Diet-Induced Obese Mice

The potentially beneficial effects of probiotics in the treatment of obesity have been generally demonstrated. In the present study, a new strain of Lactobacillus reuteri SY523 (L. reuteri SY523) with an anti-obesity effect was isolated from the fecal microbiota of diet-induced obese mice. Untargeted metabolomics analysis of mice serum showed that the significantly differential metabolite indole-3-carboxaldehyde (3-IAId) was markedly elevated in the L. reuteri SY523-treated group, and interestingly, the abundance of 3-IAId was significantly negatively associated with obesity-related indicators. As expected, in the HepG2 cell induced by free fatty acids, the potential activity of 3-IAId in restraining lipid deposition was verified. Further, we found that 3-IAId was involved in the anti-obesity effect of L. reuteri SY523 mainly via regulating the cGMP/cAMP signaling pathway. The highlight of this study lies in clarifying the pivotal role of metabolite 3-IAId in the anti-obesity effect induced by L. reuteri SY523, which is conducive to the development of probiotics for anti-obesity agents.

Lacticaseibacillus casei ATCC334 Ameliorates Radiation-Induced Intestinal Injury in Rats by Targeting Microbes and Metabolites

SCOPE

Gastrointestinal side effects are frequently observed in patients receiving medical radiation therapy. As Lacticaseibacillus casei ATCC334 potentially affects microbial ecosystem, the study hypothesizes that it may improve radiation-induced intestinal injury in rats by modulating the "gut microbiota-metabolite-barrier axis."

METHODS AND RESULTS

Rats are fed one of three or no doses of L. casei ATCC334 for 7 days and then expose to a single dose of 9 Gy X-ray total abdominal irradiation. Supplementation with L. casei ATCC334 promote the proliferation of intestinal stem cells (ISCs), increase the expression of tight junction proteins, reduce intestinal permeability, and protect intestinal barrier integrity. Moreover, 16S rRNA sequencing show that medium and high doses of L. casei ATCC334 inhibit the growth of Escherichia/Shigella and favor Akkermansia proliferation. L. casei ATCC334 intervention reprogram the metabolic profile and inhibit putrescine production but promote alpha-linolenic acid (ALA) production. Notably, a decrease in putrescine and an increase in ALA are significantly correlated with the proliferation of ISCs and enhanced intestinal barrier function following L. casei ATCC334 intervention.

CONCLUSION

These results highlight that medium and high doses of L. casei ATCC334 alleviate radiation-induced intestinal damage by enhancing the mucosal barrier and remodeling the gut microbiota structure and metabolic activity.

Lactobacillus reuteri MJM60668 Prevent Progression of Non-Alcoholic Fatty Liver Disease through Anti-Adipogenesis and Anti-inflammatory Pathway

Non-alcoholic fatty liver disease (NALFD) is a disease characterized by liver steatosis. The liver is a key organ involved in the metabolism of fat, protein, and carbohydrate, enzyme activation, and storage of glycogen, which is closely related to the intestine by the bidirectional relation of the gut-liver axis. Abnormal intestinal microbiota composition can affect energy metabolism and lipogenesis. In this experiment, we investigated the beneficial effect of Lactobacillus reuteri MJM60668 on lipid metabolism and lipogenesis. C57BL/6 mice were fed a high-fat diet (HFD) and orally administrated with MJM60668. Our results showed that mice treated with MJM60668 significantly decreased liver weight and liver/body weight ratio, without affecting food intake. Serum levels of ALT, AST, TG, TCHO, and IL-1β in mice fed with MJM60668 were decreased compared to the HFD group. Investigation of gene and protein expression on the lipogenesis and lipid metabolism showed that the expression of ACC, FAS, and SREBP was decreased, and PPARα and CPT was increased. Furthermore, an increase of adiponectin in serum was shown in our experiment. Moreover, serum IL-1β level was also significantly decreased in the treated mice. These results suggested that MJM60668 can strongly inhibit lipogenesis, enhance fatty acid oxidation, and suppress inflammation. Additionally, supplementation of MJM60668 increased the proportion of Akkermansiaceae and Lachnospiracea, confirming a potential improvement of gut microbiota, which is related to mucus barrier and decrease of triglycerides levels.

Modified Montmorillonite Improved Growth Performance of Broilers by Modulating Intestinal Microbiota and Enhancing Intestinal Barriers, Anti-Inflammatory Response, and Antioxidative Capacity

This study aims to explore the effects of modified montmorillonite (MMT, copper loading) on the growth performance, gut microbiota, intestinal barrier, antioxidative capacity and immune function of broilers. Yellow-feathered broilers were randomly divided into control (CTR), modified montmorillonite (MMT), and antibiotic (ANTI) groups. Results revealed that MMT supplementation increased the BW and ADG and decreased the F/R during the 63-day experiment period. 16S rRNA sequencing showed that MMT modulated the cecal microbiota composition of broilers by increasing the relative abundance of two phyla (Firmicutes and Bacteroidetes) and two genera (Bacteroides and Faecalibacterium) and decreasing the abundance of genus Olsenella. MMT also improved the intestinal epithelial barrier indicated by the up-regulated mRNA expression of claudin-1, occludin, and ZO-1 and the increased length of microvilli in jejunum and the decreased levels of DAO and D-LA in serum. In addition, MMT enhanced the immune function indicated by the increased levels of immunoglobulins, the decreased levels of MPO and NO, the down-regulated mRNA expression of IL-1β, IL-6, and TNF-α, and the up-regulated mRNA expression of IL-4 and IL-10. Moreover, MMT down-regulated the expression of jejunal TLRs/MAPK/NF-κB signaling pathway-related genes (TLR2, TLR4, Myd88, TRAF6, NF-κB, and iNOS) and related proteins (TRAF6, p38, ERK, NF-κB, and iNOS). In addition, MMT increased the antioxidant enzyme activities and the expression of Nrf2/HO-1 signaling pathway-related genes and thereby decreased the apoptosis-related genes expression. Spearman’s correlation analysis revealed that Bacteroides, Faecalibacterium, and Olsenella were related to the inflammatory index (MPO and NO), oxidative stress (T-AOC, T-SOD, and CAT) and intestinal integrity (D-LA and DAO). Taken together, MMT supplementation improved the growth performance of broilers by modulating intestinal microbiota, enhancing the intestinal barrier function, and improving inflammatory response, which might be mediated by inhibiting the TLRs/MAPK/NF-κB signaling pathway, and antioxidative capacity mediated by the Nrf2/HO-1 signaling pathway.

Lactic Acid Bacteria Mixture Isolated From Wild Pig Alleviated the Gut Inflammation of Mice Challenged by Escherichia coli

Wild pigs usually showed high tolerance and resistance to several diseases in the wild environment, suggesting that the gut bacteria of wild pigs could be a good source for discovering potential probiotic strains. In our study, wild pig feces were sequenced and showed a higher relative abundance of the genus Lactobacillus (43.61% vs. 2.01%) than that in the domestic pig. A total of 11 lactic acid bacteria (LAB) strains including two L. rhamnosus, six L. mucosae, one L. fermentum, one L. delbrueckii, and one Enterococcus faecalis species were isolated. To investigate the synergistic effects of mixed probiotics strains, the mixture of 11 LAB strains from an intestinal ecology system was orally administrated in mice for 3 weeks, then the mice were challenged with Escherichia coli ATCC 25922 (2 × 10⁹ CFU) and euthanized after challenge. Mice administrated with LAB strains showed higher (p < 0.05) LAB counts in feces and ileum. Moreover, alterations of specific bacterial genera occurred, including the higher (p < 0.05) relative abundance of Butyricicoccus and Clostridium IV and the lower (p < 0.05) abundance of Enterorhabdus in mice fed with mixed LAB strains. Mice challenged with Escherichia coli showed vacuolization of the liver, lower GSH in serum, and lower villus to the crypt proportion and Claudin-3 level in the gut. In contrast, administration of mixed LAB strains attenuated inflammation of the liver and gut, especially the lowered IL-6 and IL-1β levels (p < 0.05) in the gut. Our study highlighted the importance of gut bacterial diversity and the immunomodulation effects of LAB strains mixture from wild pig in gut health.