Polygonatum odoratum polysaccharide attenuates lipopolysaccharide‐induced lung injury in mice by regulating gut microbiota

Abstract Polygonatum odoratum is appreciated for its edible and medicinal benefits especially for lung protection. However, the contained active components have been understudied, and further research is required to fully exploit its potential application. We aimed to probe into the beneficial effects of Polygonatum odoratum polysaccharide (POP) in lipopolysaccharide‐induced lung inflammatory injury mice. POP treatment could ameliorate the survival rate, pulmonary function, lung pathological lesions, and immune inflammatory response. POP treatment could repair intestinal barrier, and modulate the composition of gut microbiota, especially reducing the abundance of Klebsiella, which were closely associated with the therapeutic effects of POP. Investigation of the underlying anti‐inflammatory mechanism showed that POP suppressed the generation of pro‐inflammatory molecules in lung by inhibiting iNOS+ M1 macrophages. Collectively, POP is a promising multi‐target microecological regulator to prevent and treat the immuno‐inflammation and lung injury by modulating gut microbiota.


| INTRODUC TI ON
Polygonatum odoratum, also known as fragrant Solomon's seal, is a species of flowering plant in the Asparagaceae family.In addition to the ornamental qualities, it is also highly valued for its edible and medicinal properties (Zhou et al., 2015).The rhizomes of the plant are consumed in a variety of dishes including the soups and stews in some cultures.This part of the plant is also used in traditional Chinese medicine (TCM) as Polygonati Odorati Rhizoma (Yu- Zhu) with the efficacy in "nourishing yin and moistening dryness" and "producing saliva and quenching thirst," which are commonly used in the treatment of lung diseases such as cold and dry cough and thirst due to diabetes.While the dried and powdered rhizomes can be used as a medicinal tea that is believed to have various health benefits, such as improving circulation, boosting immunity, and reducing inflammation (Committee for the Pharmacopoeia of PR China, 2020; Zhao et al., 2018).Despite its long history of being utilized both as the food source and herbal medicine with high nutritional value, the active components responsible for the efficacy of P. odoratum remain understudied.This constitutes a gap in the current understanding of this species and its potential application, warranting further research and investigation.
Polygonatum odoratum polysaccharide (POP), a main active component of P. odoratum, has been associated with antidiabetic, antialcohol-induced liver injury, and immunomodulatory effects (Liu et al., 2015;Zhao et al., 2019;Zhu et al., 2022).As biological macromolecules, most of polysaccharides cannot be directly absorbed by the gastrointestinal tract, but as a key carbon source required for the growth of probiotics, it can indirectly produce beneficial effects by promoting the proliferation of probiotics and converting them into active metabolites into the system (Zhang et al., 2022).
POP has been reported to enhance species richness and improve the community structure of gut microbiota, characterized by reducing the relative abundances of Clostridium, Enterococcus, Coprobacillus, Lactococcus, and Sutterella in high-fat diet-induced obesity rats (Wang et al., 2018).
Inflammatory injury in lungs is initiated by a complex series of events.In some extreme cases, it can develop into the acute respiratory distress syndrome and multiple organ failure, threatening the patient's life.Even if the patients can survive, the pulmonary function has been seriously damaged and is difficult to be cured (Wang et al., 2020).Notably, alterations in the gut microbiota have been recognized in many immunoinflammatory disorders, and attenuation of the gut microbiota dysbiosis may have the positive effect on lung injury (Dhar & Mohanty, 2020).Although the host's immunoinflammatory response is a multi-factor, multi-step, and multi-phase process, for the polysaccharides that is orally administrated in most cases, gut microbiota has been regarded as one of the key targets in the prevention and treatment of the immunoinflammatory disorders and the associated respiratory diseases (Li et al., 2021).However, the effects of POP on lung inflammatory injury via modulation of gut microbiota have not been investigated.We thereby presume POP might be a potential prebiotic to improve gut dysbiosis, which can lead to a reduction of systemic immune inflammation and contribute to the amelioration of lung injury.
In this work, we were aimed to investigate the effects of POP in alleviation of lung injury via gut microbiota modulation on lipopolysaccharide (LPS)-induced inflammatory mice models.By employing 16S rRNA sequencing and fecal transplantation techniques, the relationship between gut microbiota composition and lung injury-related parameters altered by POP was directly investigated.
Furthermore, the anti-inflammatory mechanisms of POP in lung associated with gut microbiota modulation were explored by multiplex cytokine analysis and immunofluorescent assays.Our findings may offer the biological basis for clarifying the "nourishing yin and moistening dryness" effects of Polygonati Odorati Rhizoma based on the gut, and contribute to the development of clinically available anti-immunoinflammatory and lung protective agent for lung injury treatment.

| Chemicals and reagents
The material of P. odoratum (batch NO:191201091)

| Preparation of P. odoratum polysaccharide
The POP was prepared by water extraction and the alcohol precipitation method according to previous study (Fu et al., 2020;Hu et al., 2022).Briefly, the material of P. odoratum was crushed into powder and refluxed twice with deionized water (liquid-solid ratio at 10:1) at 100°C for 2 h.The extracted solution (about 5 L) was pooled and further concentrated to 1/7 of the initial volume under reduced pressure at 50°C.The concentrated solution was combined and precipitated by adding 95% ethanol (to finial 80%, v/v), and standing at 4°C for 24 h.The resultant precipitate was lyophilized to obtain the total POP powder (with the extraction rate of 12.7%).The content of polysaccharides was determined by the sulfuric acid-phenol method (Fu et al., 2020), and POP was composed of 66.36% carbohydrates (Table S1).
All animal experiments strictly complied with the Guide for the Care and Use of Laboratory Animals and approved by the Animal Ethics Committee of Tianjin University of Traditional Chinese Medicine (TCM-LAEC2021053).

| LPS-induced inflammatory model and POP administration
LPS injection induced lung injury in vivo due to a high immunoinflammatory response, and the lung injury models in this study were induced by reference to the previous study (Lv et al., 2023).After a week of adaption, the mice were randomly divided into six groups (15 mice for each): control (Con) group, LPS group, dexamethasone (DEX) group (5 mg/kg), and three levels of polysaccharides-treated (POP-100, -200, and -400 mg/kg) groups.Besides the Con group, all the others were injected with LPS into the tail vein at the dose of 5 mg/kg from the third to the fifth day of drug administration for modeling.The drugs of DEX and POP dissolved in double distilled water were given to mice once a day by gavage for 7 days.The Con and LPS group mice were received the same volume of double distilled water.All the mice were sacrificed under the deeply anesthetized condition after the morphology examinations and pulmonary function by the pulmonary system (software-iox2, EMKA Technologies, France) (Zhang et al., 2021).

| Fecal microbiota transplantation (FMT)
The FMT was performed under the anaerobic condition.Fresh feces from donors were pooled and homogenized, diluted in sterile saline with a final concentration of 100 mg feces/mL.The suspension was adequately mixed and placed stably for 10 min.Afterwards, the supernatant was collected and used for FMT.Before the FMT, the donors were treated with POP-400 mg/kg (Con+POP400), and the receptors were treated with antibiotic cocktail of 0.5 g/L vancomycin, 1 g/L neomycin, 1 g/L metronidazole, and 1 g/L ampicillin for 3 days.Within the next 7 days, FMT group receipted intragastric administration of the supernatant from donor mice (10 μL/g) once a day.

| Immunoinflammatory assays
The numbers of the immune cells, including the white blood cell (WBC), lymphocyte (LY), neutrophil (NE), and monocyte (MO), were tested immediately by an automated hematology analyzer (MEK-7222K) in the blood of mice, which was collected before the euthanasia using the eyeball-extraction method and incubated with EDTA at the room temperature.The cytokine concentrations of TNFα, IL-6, and IL-1β in serum and lung tissue, were determined by the corresponding ELISA kits (Sinobestbio), and detected by the spectrophotometry (UV-3100, Mapada).

| Tissue pathological examination
Lung, spleen, and colon tissues of mice were collected, washed with PBS, drained well with the filter paper, and then weighed.The relative weight of tissue was equal to the weight of the tissue divided by the body weight.The tissues were snap-frozen in liquid nitrogen for further analysis.Lung and parts of the colon were fixed in 4% paraformaldehyde for 48 h, embedded in paraffin and cut into 5μm slices, and stained with hematoxylin-eosin (H&E).The pathological injury of lung and colon tissues was observed and imaged by the light microscope (Leica DM750).

| Microbial diversity analysis
Fresh fecal samples were collected before the administration, modeling, and euthanasia under sterile condition, and immediately frozen at −80°C.The microbial genome DNA was extracted, and the 16S rRNA genes of V3-4 regions were amplified using primers 338F and 806R, and then purified, quantified, and paired-end sequenced on the Illumina MiSeq platform (Illumina).The raw reads were deposited into the NCBI Sequence Read Archive database (Accession Number: SRP371245), and then analyzed according to the previous study (Zhao et al., 2022).

| Multiplex cytokine analysis
Multiplex cytokine analysis is based on multiplex microbead Luminex technology enabling the quantification of multiple analytes in a single assay.Th17 cell and related cytokines can interact with other immune cells and modulate immune responses, which are key contributors to lung injury (Xia et al., 2020).Inflammatory cytokines in the lung tissue were analyzed via a multiplexing magnetic bead-based antibody detection kit (Milliplex MAP Mouse Th17 Kit, Millipore; Cat: MTH17MAG-47K) following with the manufacturer's instructions and previous study (Vrselja et al., 2019).The proteins of lung tissues were extracted in ice-cold modified by using the RIPA kit (Solarbio Life Science).After determining protein concentrations

| Statistical analysis
Data are expressed as mean ± SEM (standard error of the mean).GraphPad Prism 7.0 was used for all statistical analyses.One-way ANOVA was used for comparison among the multiple groups.
Difference between the pairwise groups was tested for the statistical significance by the student's t-test, and p < .05 was considered with the statistical significance.

| POP protects the survival condition, alleviates lung injury, and the immunoinflammatory response
The survival rate was 100% in the Con group, whereas that of the LPS group decreased to 60% (p < .05)(Figure 1a,b).The DEX and different doses of POP treatment (100, 200, and 400 mg/kg) could significantly improve the survival rate, especially for the mice with high-dose POP, for which the survival rate could ascend to nearly 90%.Compared to the Con group, the mice in the LPS group exhibited pilomotor fur, mental fatigue, and wet feces.After POP treatment, the spirit, fur, feces, and other characteristics, were ameliorated and generally recovered with dose dependence (vs.LPS) (Figure 1c).Progressive weight gain in the Con group was observed, while the weight decreased continuously from the fourth day until the injection of LPS was stopped.Daily treatment with high dose of POP (400 mg/kg) could significantly reduce the weight loss (p < .01, vs. LPS) (Figure 1d,e).As one of the important evaluation indexes for lung injury development, the pulmonary function was examined.
The continuous data of mice in the steady breathing state within 5 min were collected, and the average value of tidal volume (TV) and minute ventilation (MV) within 15 min was calculated (Figure 1f-i).
Compared with the Con group, the TV and MV values significantly decreased for the LPS group, but significantly increased by the POP treatment in a dose-dependent manner (400 mg/kg, TV: p < .001,MV: p < .001).The DEX treatment could also significantly improve the weight loss and the pulmonary function.Thus, the 400 mg/kgdose POP intervention not only reduced the mortality rate in mice induced by LPS, but also significantly improved the weight loss and pulmonary function, which thus provided the effectiveness and application potential of POP in the treatment of immuno-inflammation and lung injury (Devaney et al., 2011;Meng et al., 2018).
Compared with the Con group, pulmonary hemorrhage and edema were noted in the LPS-treated mice, and treatment with high dose of POP (400 mg/kg) could obviously alleviate this phenomenon (Figure 1j).Moreover, the relative weight of lung tissue was increased in the LPS group compared to the Con group (p < .001),while the high dose of POP treatment could decrease it from 0.0097 ± 0.00023 to 0.0084 ± 0.00018 (p < .05, vs. LPS) (Figure 1k).Pathological lesions in lung tissue of LPS-induced inflammatory mice were observed under the light microscopy after H&E staining.Compared with the Con group, the lung staining sections of LPS group exhibited a thickened alveolar septum, marked inflammatory cell infiltration, and increased the proportion of lung parenchyma.After treatment with DEX and high dose of POP, the lung pathological changes were attenuated (vs.LPS), but not observed for the other lower doses of POP groups (Figure 1l).The relative weight of spleen tissue was changed as observed for the lung tissue, after being treated with the high dose of POP (Figure S1a,b).LPS treatment significantly increased hematologic indices of WBC, NE, LY, and MO, which was decreased by the POP treatment in a dose-dependent manner (Figure S1c-f).
Specifically, the high-dose POP markedly reverted those four hematologic indices mentioned above (WBC, NE, MO: p < .001,LY: p < .01, vs. LPS).Given that the regulation of pro-inflammatory cytokines is crucial to prevent excessive inflammation and tissue damage in the lungs (Cheng et al., 2022;Simons et al., 1996), we investigated the effects of POP in regulating the expression of pro-inflammatory cytokines, including TNFα, IL-1β, and IL-6, both in the lung and serum samples by ELISA (Figure 1m,n).POP groups could significantly decrease the TNFα level in the lung tissue, and the largest decrease was detected in the high-dose group (p < .001, vs. LPS).The highdose group showed the downregulated expression of IL-6 and IL-1β both in the lung tissue and serum (p < .05, vs. LPS).

| POP improves intestinal barrier function and gut microbial diversity
Literature has reported that, compared with the Con group, LPS injection could induce disordered colon mucosa structure, crypt atrophy, and inflammatory cell infiltration (Chen et al., 2021).In this work, POP intervention ameliorated the colonic injury which was characterized by the disordered colon mucosa structure with crypt atrophy and inflammatory cell reduction (vs.LPS) (Figure 2a).
POP treatment also upregulated the expression of intestinal tight junction proteins (e.g., ZO-1 and occludin) contributing to gut barrier integrity (Figure 2b,c).Particularly, the high-dose POP treatment displayed remarkable effects on the intestinal barrier function recovery induced by LPS and might be associated with gut microbiota regulation.
LPS could lead to a decreased gut microbial richness (Figure 2d-g).
Compared with the Con group, the Chao was significantly decreased in the LPS group (p < .01).After high-dose POP treatment for 7 days, the Chao index was significantly increased (p < .05, vs. LPS).The same enhancing trend was detected in the ACE, Shannon, and PD.
Additionally, the low-and middle-dose groups could also increase the gut microbial diversity, but no significant difference was observed compared with the LPS group.Principal coordinate analysis (PCoA) indicated the obvious difference between the LPS and Con samples, and the high dose of POP-treated samples were separated from the LPS group and the other doses-treated samples (Figure 2h).

| POP modulates the lung injury-related bacteria
The changes of the gut microbiota of mice by LPS modeling and POP administration time were analyzed.Before the LPS injection, the position of different doses of POP-treated samples could be separated from that of the Con samples in the PCoA (Figure 3a), indicating that the short-term POP intervention for 3 days could alter the composition of the gut microbiota.Compared with the pre-LPS group or Con group, the abundance of norank_f_Muribaculaceae and Escherichia-Shigella showed the negative correlation (Figure 3e).

| FMT from POP-fed mice attenuates gut dysbiosis and lung injury
Fecal microbiota from POP-fed mice were transplanted into LPSinjected recipients (Figure 4a).Notably, the gut barrier protective effects of POP were transferable by fecal transplantation.These observations were accompanied by increased expression of ZO-1 and occludin (Figure 4b,c).In order to evaluate the effectiveness of FMT, we observed the alteration of gut microbiota during FMT (Figure S2a,b).FMT treatment remodeled the gut microbiome after antibiotic administration and LPS induction, characterized by decreasing the abundance of phylum Proteobacteria, and increasing the abundance of Firmicutes (Figure S2c,d).FMT treatment enriched the abundance of Lactobacillus, and reduced the abundance of Klebsiella (Figure S2e-f).The abundance of Lactobacillus, Precotellaceae UCG-001, and unclassified_f_Lachnospiraceae also had an up-regulation effect after eating POP in normal donor mice (Figure S2g-h).
Given that FMT ameliorated the gut dysbiosis, we examined whether the beneficial effects of POP may be mediated by the gut microbiota.Compared with the LPS group, the survival rate of FMT group increased from 58.33% to 83.33% (Figure 4e), which was consistent with the previous study (Tang et al., 2021).The body weight of FMT mice was slightly increased, and the pulmonary function was significantly improved (vs.LPS) (Figure S3a-g).Notably, FMT significantly decreased the number of immune cells including WBC, NE, LY, and MO in peripheral blood, compared with the LPS group (Figure 4f).Also, the relative weight of spleen was significantly reduced by FMT (Figure S3h-i, p < .01, vs. LPS).In addition, FMT also reduced the level of TNFα, IL-6, and IL-1β both in serum (Figure 4g) and lung tissue (Figure 4h).These results indicated that the gut microbiota contributed to the anti-immunoinflammatory effects performed by POP.Recent studies showed that FMT not only improved immunoinflammatory response, but also had certain potential for respiratory disease (Liu et al., 2017).As shown in Figure 4i-k, the relative weight of the lungs was reduced (p < .05, vs. LPS), and the pathological damage was reversed, which showed that the alveolar wall thickness was close to Con group, and the inflammatory cell infiltration in the lung space was reduced.FMT treatment also restored the structure of colon and reduced infiltration of inflammatory cells (Figure S3j).

| POP and FMT exert the anti-inflammatory effect by suppressing M1 macrophage in lung
The associated molecular mechanisms of POP on immuno- The results showed that POP and FMT downregulated the iNOS + macrophages, which were presenting the M1 macrophage.But there was no obvious effect on CD206 + macrophages (Figure 5b,c).Our results suggested that POP ameliorated lung injury through suppression of the immuno-inflammation, which was in association with modulating the gut microbiota.

| DISCUSS ION
P. odoratum have Yin-nourishing and lung-moistening functions in TCM, and are often used as functional foods to benefit the health.
Polysaccharides isolated from P. odoratum can exhibit milder immunomodulatory activity on cell viability and IL-6 production of RAW 264.7 macrophages, and promote the activity of T LYs in vitro (Zhao et al., 2019).In this study, the therapeutic effects of POP against systemic and pulmonary cytokine release syndrome caused by pathogens such as bacteria or viruses were explored in vivo.Using the LPS-induced lung inflammatory injury mice model (Lv et al., 2023), the therapeutic potential of POP as a lung protective agent has been confirmed, and its beneficial activity of modulating the associated gut microbiota.Besides, the 400 mg/kg-dose POP interventions not only reduced the mortality rate from 40% to 10% induced by LPS in mice, but also significantly improved the weight loss, pulmonary function, and pulmonary edema.
Previous studies (Agudelo-Ochoa et al., 2020;Zuo et al., 2020) have shown that the gut microbiota of patients with lung injury significantly changed compared with normal subjects, which is characterized by enrichment of opportunistic pathogens and depletion of beneficial commensals.LPS can disrupt the integrity of the gut barrier, leading to increased intestinal permeability (Yoseph et al., 2016), inflammatory response and contribution to exacerbation of lung injury (Dickson, 2016).The immune activation and inflammation can disrupt the delicate balance of the gut microbiota, resulting in changes in its diversity and abundance.In turn, gut microbiota dysbiosis can contribute to the translocation of microbial components from the gut lumen into systemic circulation, which is a potential factor of inflammation and immune-related pathology (Bai et al., 2022;Pickard et al., 2017), and further affect pulmonary immunity through a vital cross-talk between gut and lung, as gut-lung axis.Alterations in the gut microbial species and metabolites have been linked to changes in immune responses and inflammation as well as the lung injury development.As a signature feature of gut dysbiosis, the abundance of Proteobacteria was significantly decreased in the high-dose group (p < .05, vs. LPS), suggesting a closely link with the therapeutic effects of POP (Shin et al., 2015).The enhancement of the proportion of Lactobacillus (Hossain et al., 2022), Muribaculaceae (Tian et al., 2021), and Prevotellaceae UCG-001 (Zhu et al., 2021), the SCFA-producing bacteria, can mitigate colonic barrier dysfunction and inflammation and inhibit the endotoxin production.Additionally, the reduction of harmful bacteria including Escherichia-shigella and Klebsiella, which were the typical LPS producing, gram-negative bacteria, had been confirmed to ameliorate the lung injury (Sun et al., 2020).Notably, Klebsiella could disrupt the gut barrier (Nakamoto et al., 2019), which not only trigger a systemic or local inflammatory response that further altering the overall immune homeostasis of the host to exacerbate the occurrence of inflammatory lung injury (Belkaid & Hand, 2014), but also lead to a risk factor for pneumonia-induced lung injury (Liu et al., 2018).Lactobacillus, a genus of beneficial bacteria, can inhibit the growth and activity of Klebsiella (Tang et al., 2022).As a potential prebiotic-like polysaccharide, POP might promote the growth of Lactobacillus to inhibit the growth and activity of Klebsiella.Our results indicated that the therapeutic mechanism of POP that are not directly absorbed was associated with the remodeling the gut microbiota.
Moreover, the observed gut microbiota composition shift might be a direct response to the POP's administration, so as to reach the anti-immune inflammatory states via the innate immune signaling pathway, rather than a direct involvement in disease severity by POP (Ji et al., 2014).Our results suggested that POP alleviated LPS-induced immuno-inflammation and lung injury in association with modulating gut microbiota, which may be related to the inhibition of inflammation, protection of intestinal barrier, and regulation of mucosal immunity through a vital cross-talk between gut and lung, as the gut-lung axis (Yang & Cong, 2021).The results of TNFα, IL-1β, and IL-6 were consistent with the previous results during the lung inflammation development.IL-28B and IL-13 may also modulate the lung inflammation through suppressing the generation of pro-inflammatory molecules (Yan et al., 2017).While using the multiplex Luminex panel to evaluate the cytokine expression was more sensitive and advanced, allowing the detection of more factor changes (Johnson et al., 2019).It has been reported that the TLR4 signaling pathway played an important role in the development of pro-inflammatory cytokine expression and M1 macrophage activation (Zhang et al., 2022).TLR4 was a sensor mediating the crosstalk between the intestinal commensal microbiome and host immunity, and the gut commensal present significant antiinflammation effects during microbial respiratory infections by inhibiting TLR4 and its signal transduction (Wu et al., 2022).LPS-induced inflammation was involved in the activation of MAPKs, NF-κB, and JAK signal pathway (Lai et al., 2017) thereby resulting in the overproduction of cytokines, such as TNFα, IL-1β, and IL-6 (Dang & Marsland, 2019).
Our results suggested that POP ameliorated the lung injury through suppression of pro-inflammatory M1 macrophages, which was in association with modulating the gut microbiota.Polysaccharides can modulate the gut microbiota composition and production of metabolites, such as SCFAs, leading to anti-inflammatory effects.More work is needed to understand the mechanisms, and context, for how gut microbes or metabolites, selectively prime myeloid precursors in the gut-lung axis upon inflammation and if this also holds true during homeostasis (Dang & Marsland, 2019;Nan et al., 2023).Additional studies on the underlying mechanisms could give valuable insight on how to modulate the immune system at one of its most fundamental levels for therapeutic purposes.
In conclusion, POP could significantly ameliorate the immunoinflammation and lung injury by modulating the gut microbiota, protecting the intestinal barrier, inhibiting the M1 macrophages in LPS-induced inflammatory injury mice.Our findings elucidated the biological basis of POP to improve lung inflammatory injury from the perspective of regulating gut microbiota, and provided new ideas to develop the nutritional prevention and treatment strategy of lung protection based on the gut.These results favor that POP may be used as a prebiotic agent for targeting the gut microbiota against the inflammation-related diseases.
was purchased from Hebei Chunkai Pharmaceutical Co., Ltd, China, and authenticated by Dr. Lijuan Zhang from Tianjin University of Traditional Chinese Medicine (Tianjin, China).
of each sample by BCA protein quantification kit (Beyotime Institute of Biotechnology), 25 μg of protein per sample was loaded onto the multiplex plate for each well approximately.Standard curves for each analyte were generated and the results were analyzed by Bio-Plex 200 System (Luminex xMAP, BIO-RAD).

F
Polygonatum odoratum polysaccharide (POP) exerts protective effects on the survival condition and lung injury.(a) The schematic diagram for modeling and administration pipeline in lipopolysaccharide (LPS)-induced mice; (b) survival rate; (c) representative morphology of mice before euthanasia; (d) body weight of LPS-induced mice after 7-day treatment; (e) the change of body weight after 7-day treatment; Observation of (f) TV and (g) MV in 5 consecutive and steady minutes, and statistical analysis of (h) TV and (i) MV within 10 min; (j) representative picture and (k) the relative weight of lung tissue; (l) representative pictures of hematoxylin-eosin in the lung tissue; The effects of POP on the inflammatory biomarkers (m) in the lung tissue TNFα, IL-6, IL-1β, and (n) in the serum TNFα, IL-6, and IL-1β (mean ± SEM, n = 6, ## p < .01 vs. Con, ### p < .001 vs. Con, **p < .01 vs. LPS, ***p < .001 vs. LPS).
Tang et al. (2021) stablished a gut flora disorder model with administration antibiotics in LPS-induced acute lung injury mice, and found that FMT improved the imbalance and diversity of the gut flora-induced and -antagonized LPS.The gut microbiota was modulated by a short-term (3-day) POP pre-intervention and the trend was sustained of Lactobacillus in the donor mice, which played important roles in gut microbiota for prevention in LPS-induced injury.