Lentinan improves intestinal inflammation and gut dysbiosis in antibiotics-induced mice

Lentinan Ameliorates β-Hydroxybutyrate-Induced Lipid Metabolism Disorder in Bovine Hepatocytes by Upregulating the Expression of Acetyl-coenzyme A Acetyltransferase 2

Ketosis in dairy cows is often accompanied by the dysregulation of lipid homeostasis in the liver. Acetyl-coenzyme A acetyltransferase 2 (ACAT2) is specifically expressed in the liver and is important for regulating lipid homeostasis in ketotic cows. Lentinan (LNT) has a wide range of pharmacological activities, and this study investigates the protective effects of LNT on β-hydroxybutyrate (BHBA)-induced lipid metabolism disorder in bovine hepatocytes (BHECs) and elucidates the underlying mechanisms. BHECs were first pretreated with LNT to investigate the effect of LNT on BHBA-induced lipid metabolism disorder in BHECs. ACAT2 was then silenced or overexpressed to investigate whether this mediated the protective action of LNT against BHBA-induced lipid metabolism disorder in BHECs. Finally, BHECs were treated with LNT after silencing ACAT2 to investigate the interaction between LNT and ACAT2. LNT pretreatment effectively enhanced the synthesis and absorption of cholesterol, inhibited the synthesis of triglycerides, increased the expression of ACAT2, and elevated the contents of very low-density lipoprotein and low-density lipoprotein cholesterol, thereby ameliorating BHBA-induced lipid metabolism disorder in BHECs. The overexpression of ACAT2 achieved a comparable effect to LNT pretreatment, whereas the silencing of ACAT2 aggravated the effect of BHBA on inducing disorder in lipid metabolism in BHECs. Moreover, the protective effect of LNT against lipid metabolism disorder in BHBA-induced BHECs was abrogated upon silencing of ACAT2. Thus, LNT, as a natural protective agent, can enhance the regulatory capacity of BHECs in maintaining lipid homeostasis by upregulating ACAT2 expression, thereby ameliorating the BHBA-induced lipid metabolism disorder.

Dress me an outfit: advanced probiotics hybrid systems for intelligent IBD therapy

Inflammation bowel disease (IBD) has emerged as a public health challenge worldwide; with high incidence and rapid prevalence, it has troubled billions of people and further induced multitudinous systemic complications. Recent decade has witnessed the vigorous application of food-borne probiotics for IBD therapy; however, the complicated and changeable environments of digestive tract have forced probiotics to face multiple in vivo pressures, consequently causing unsatisfied prophylactic or therapeutic efficacy attributed to off-targeted arrival, damaged viability, insufficient colonization efficiency, etc. Fortunately, arisen hybrid technology has provided versatile breakthroughs for the targeted transplantation of probiotics. By ingeniously modifying probiotics to form probiotics hybrid systems (PHS), the biological behaviors of probiotics in vivo could be mediated, the interactions between probiotics with intestinal components can be facilitated, and diverse advanced probiotic-based therapies for IBD challenge can be developed, which attribute to the intelligent response to microenvironment of PHS, and intelligent design of PHS for multiple functions combination. In this review, various PHS were categorized and their intestinal behaviors were elucidated systematically, their therapeutic effects and intrinsic mechanism were further analyzed. Besides, shortages of present PHS and the corresponding solutions have been discussed, based on which the future perspectives of this field have also been proposed. The undeniable fact is that PHS show an incomparable future to bring the next generation of advanced food science.

The regulatory effect of polysaccharides on the gut microbiota and their effect on human health: A review

Polysaccharides with low toxicity and high biological activities are a kind of biological macromolecule. Recently, growing studies have confirmed that polysaccharides could improve obesity, diabetes, tumors, inflammatory bowel disease, hyperlipidemia, diarrhea, and liver-related diseases by changing the intestinal micro-environment. Moreover, polysaccharides could promote human health by regulating gut microbiota, enhancing production of short-chain fatty acids (SCFAs), improving intestinal mucosal barrier, regulating lipid metabolism, and activating specific signaling pathways. Notably, the biological activities of polysaccharides are closely related to their molecular weight, monosaccharide composition, glycosidic bond types, and regulation of gut microbiota. The intestinal microbiota can secrete glycoside hydrolases, lyases, and esterases to break down polysaccharides chains and generate monosaccharides, thereby promoting their absorption and utilization. The degradation of polysaccharides can produce SCFAs, further regulating the proportion of gut microbiota and achieving the effect of preventing and treating various diseases. This review aims to summarize the latest studies: 1) effect of polysaccharides structures on intestinal flora; 2) regulatory effect of polysaccharides on gut microbiota; 3) effects of polysaccharides on gut microbe-mediated diseases; 4) regulation of gut microbiota on polysaccharides metabolism. The findings are expected to provide important information for the development of polysaccharides and the treatment of diseases.

The gut microbiome, resistome, and mycobiome in preterm newborn infants and mouse pups: lack of lasting effects by antimicrobial therapy or probiotic prophylaxis

BACKGROUND

Enhancing our understanding of the underlying influences of medical interventions on the microbiome, resistome and mycobiome of preterm born infants holds significant potential for advancing infection prevention and treatment strategies. We conducted a prospective quasi-intervention study to better understand how antibiotics, and probiotics, and other medical factors influence the gut development of preterm infants. A controlled neonatal mice model was conducted in parallel, designed to closely reflect and predict exposures. Preterm infants and neonatal mice were stratified into four groups: antibiotics only, probiotics only, antibiotics followed by probiotics, and none of these interventions. Stool samples from both preterm infants and neonatal mice were collected at varying time points and analyzed by 16 S rRNA amplicon sequencing, ITS amplicon sequencing and whole genome shotgun sequencing.

RESULTS

The human infant microbiomes showed an unexpectedly high degree of heterogeneity. Little impact from medical exposure (antibiotics/probiotics) was observed on the strain patterns, however, Bifidobacterium bifidum was found more abundant after exposure to probiotics, regardless of prior antibiotic administration. Twenty-seven antibiotic resistant genes were identified in the resistome. High intra-variability was evident within the different treatment groups. Lastly, we found significant effects of antibiotics and probiotics on the mycobiome but not on the microbiome and resistome of preterm infants.

CONCLUSIONS

Although our analyses showed transient effects, these results provide positive motivation to continue the research on the effects of medical interventions on the microbiome, resistome and mycobiome of preterm infants.

Effects of glycyrrhiza polysaccharides on growth performance, meat quality, serum parameters and growth/meat quality-related gene expression in broilers

With growing restrictions on the use of antibiotics in animal feed, plant extracts are increasingly favored as natural feed additive sources. Glycyrrhiza polysaccharide (GP), known for its multifaceted biological benefits including growth promotion, immune enhancement, and antioxidative properties, has been the focus of recent studies. Yet, the effects and mechanisms of GP on broiler growth and meat quality remain to be fully elucidated. This study aimed to investigate the effects of GP on growth, serum biochemistry, meat quality, and gene expression in broilers. The broilers were divided into five groups, each consisting of five replicates with six birds. These groups were supplemented with 0, 500, 1,000, 1,500, and 2,000 mg/kg of GP in their basal diets, respectively, for a period of 42 days. The results indicated that from day 22 to day 42, and throughout the entire experimental period from day 1 to day 42, the groups receiving 1,000 and 1,500 mg/kg of GP showed a significant reduction in the feed-to-gain ratio (F:G) compared to the control group. On day 42, an increase in serum growth hormone (GH) levels was shown in groups supplemented with 1,000 mg/kg GP or higher, along with a significant linear increase in insulin-like growth factor-1 (IGF-1) concentration. Additionally, significant upregulation of GH and IGF-1 mRNA expression levels was noted in the 1,000 and 1,500 mg/kg GP groups. Furthermore, GP significantly elevated serum concentrations of alkaline phosphatase (AKP) and globulin (GLB) while reducing blood urea nitrogen (BUN) levels. In terms of meat quality, the 1,500 and 2,000 mg/kg GP groups significantly increased fiber density in pectoral muscles and reduced thiobarbituric acid (TBA) content. GP also significantly decreased cooking loss rate in both pectoral and leg muscles and the drip loss rate in leg muscles. It increased levels of linoleic acid and oleic acid, while decreasing concentrations of stearic acid, myristic acid, and docosahexaenoic acid. Finally, the study demonstrated that the 1,500 mg/kg GP group significantly enhanced the expression of myogenin (MyoG) and myogenic differentiation (MyoD) mRNA in leg muscles. Overall, the study determined that the optimal dosage of GP in broiler feed is 1,500 mg/kg.

Purple Sweet Potato Polysaccharide Exerting an Anti-inflammatory Effect via a TLR-Mediated Pathway by Regulating Polarization and Inhibiting the Inflammasome Activation

Purple sweet potato polysaccharide (PSPP-1) is a novel glucan; this study aimed to examine the anti-inflammatory effect of PSPP-1 and elucidate its potential mechanisms. Lipopolysaccharide (LPS)-induced RAW264.7 was used as the model of inflammation, cell viability, and levels of nitric oxide (NO), reactive oxygen species (ROS), and calcium ion (Ca2+) were analyzed. ELISA and qPCR were used to assess the productions and mRNA expression of cytokines, and Western blotting was used to assess protein expressions in the TLR-mediated pathway, macrophage polarization, and inflammasome activation. The results demonstrated PSPP-1 inhibited cell proliferation and markedly decreased NO, ROS, and Ca2+ levels. Moreover, PSPP-1 suppressed the secretions and mRNA expressions of pro-inflammatory cytokines and increased those of anti-inflammatory cytokines. Furthermore, PSPP-1 could exert anti-inflammatory effects through different pathways mediated by both TLR2 and TLR4, which modulated the expressions of essential proteins in the myeloid differentiation factor 88 (MyD88)-dependent and toll/IL-1 receptor domain-containing adaptor-inducing interferon-β (TRIF)-dependent signaling pathways. PSPP-1 even regulated the polarization of M1/M2 macrophages and inhibited the nucleotide oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation. These findings indicate that PSPP-1 can suppress LPS-induced inflammation via multiple pathways and may be a potential agent for therapeutic inflammation-related pathophysiological processes and disorders.

Composition, structural properties and immunomodulatory activity of several aqueous Pleurotus β-glucan-rich extracts

In this work, aqueous extracts from six different Pleurotus species were obtained and their yield, gross composition, β-glucan content, monosaccharide profile, thermal stability, molecular weight distribution, and FT-IR were analyzed before and after purification through ethanol precipitation of the carbohydrate-rich fractions. The bioactivity (anti-inflammatory and immunomodulatory activity) of the various fractions obtained was also analyzed in three different cell cultures and compared with a lentinan control. The trend observed after purification of the aqueous fractions was an increase in the concentration of polysaccharides (especially β-glucans), a decrease in ash, glucosamine and protein content and the elimination of low molecular weight (Mw) compounds, thus leaving in the purified samples high Mw populations with increased thermal stability. Interestingly, all these purified fractions displayed immunomodulatory capacity when tested in THP-1 macrophages and most of them also showed significant activity in HEK-hTLR4 cells, highlighting the bioactivity observed for Pleurotus ostreatus (both the extracts obtained from the whole mushroom and from the stipes). This specific species was richer in heteropolysaccharides, having moderate β-glucan content and being enriched upon purification in a high Mw fraction with good thermal stability.

Harnessing the power of traditional Chinese medicine monomers and compound prescriptions to boost cancer immunotherapy

At present, cancer is the largest culprit that endangers human health. The current treatment options for cancer mainly include surgical resection, adjuvant radiotherapy and chemotherapy, but their therapeutic effects and long-term prognosis are unsatisfactory. Immunotherapy is an emerging therapy that has completely transformed the therapeutic landscape of advanced cancers, and has tried to occupy a place in the neoadjuvant therapy of resectable tumors. However, not all patients respond to immunotherapy due to the immunological and molecular features of the tumors. Traditional Chinese Medicine (TCM) provides a new perspective for cancer treatment and is considered to have the potential as promising anti-tumor drugs considering its immunoregulatory properties. This review concludes commonly used TCM monomers and compounds from the perspective of immune regulatory pathways, aiming to clearly introduce the basic mechanisms of TCM in boosting cancer immunotherapy and mechanisms of several common TCM. In addition, we also summarized closed and ongoing trials and presented prospects for future development. Due to the significant role of immunotherapy in the treatment of non-small cell lung cancer (NSCLC), TCM combined with immunotherapy should be emphasized in NSCLC.

Lentinan: An unexplored novel biomaterial in drug and gene delivery applications

Recently, lentinan (LNT) has been utilized for its diversified potential in research with an extended role from nutritional or medicinal applications to a novel biomaterial. LNT is a biocompatible, multifunctional polysaccharide employed as a pharmaceutical additive in engineering customized drug or gene carriers with an improved safety profile. Its triple helical structure containing hydrogen bonding offers more extraordinary binding sites for the attachments of dectin-1 receptors and polynucleotide sequences (poly(dA)). Hence, the diseases expressing dectin-1 receptors can be specifically targeted through so-designed LNT-engineered drug carriers. Gene delivery using poly(dA)-s-LNT complexes and composites has exhibited greater targetability and specificity. The achievement of such gene applications is assessed through the pH and redox potential of the extracellular cell membrane. The steric hindrance-acquiring behavior of LNT shows promise as a system stabilizer in drug carrier engineering. LNT shows viscoelastic gelling behavior temperature-dependently and therefore needs to explore more to meet topical disease applications. The immunomodulatory and vaccine adjuvant properties of LNT help in mitigating viral infections too. This review highlights the new role of LNT as a novel biomaterial, particularly in drug delivery and gene delivery applications. In addition, its importance in achieving various biomedical applications is also discussed.

Oral Administration of Lotus-Seed Resistant Starch Protects against Food Allergy

Food allergy is a serious food safety and public health issue. However, the medical interventions for allergy treatment are still suboptimal. Recently, the gut microbiome-immune axis has been considered as a promising target to reduce the symptoms of food allergy. In this study, we explore the oral administration of lotus-seed resistant starch as a means to protect against food allergy using an ovalbumin (OVA) sensitization and challenge rodent model. The results obtained showed that lotus-seed resistant starch intervention alleviated the food allergy symptoms (such as reductions in body temperature and allergic diarrhea). Furthermore, lotus-seed resistant starch also attenuated the increase in OVA-specific immunoglobulins and improved Th1/Th2 imbalance in OVA-sensitized mice. These anti-allergic effects might be associated with the actions of lotus-seed resistant starch on intestinal microbiota. Taken together, our findings suggest that daily ingestion of lotus-seed resistant starch might be effective for the alleviation of food allergy.

Oligosaccharides isolated from Rehmannia glutinosa protect LPS-induced intestinal inflammation and barrier injury in mice

Objectives

We investigated the protective effect of Rehmannia glutinosa oligosaccharides (RGO) on lipopolysaccharide (LPS)-induced intestinal inflammation and barrier injury among mice.

Methods

RGO is prepared from fresh rehmannia glutinosa by water extraction, active carbon decolorization, ion exchange resin impurity removal, macroporous adsorption resin purification, and decompression drying. LPS could establish the model for intestinal inflammation and barrier injury in mice. Three different doses of RGO were administered for three consecutive weeks. Then the weight, feces, and health status of the mice were recorded. After sacrificing the mice, their colon length and immune organ index were determined. The morphological changes of the ileum and colon were observed using Hematoxylin-eosin (H&E) staining, followed by measuring the villus length and recess depth. RT-qPCR was utilized to detect the relative mRNA expression of intestinal zonula occludens-1 (ZO-1) and occludin. The expression of inflammatory factors and oxidation markers within ileum and colon tissues and the digestive enzyme activities in the ileum contents were detected using ELISA. The content of short-chain fatty acids (SCFAs) in the colon was determined with GC. The gut microbial composition and diversity changes were determined with 16S-rRNA high-throughput sequencing. The association between intestinal microorganisms and SCFAs, occludins, digestive enzymes, inflammatory factor contents, and antioxidant indexes was also analyzed.

Results

RGO significantly increased the weight, pancreatic index, thymus index, and colon length of mice compared with the model group. Moreover, it also improved the intestinal tissue structure and increased the expression of intestinal barrier-related junction proteins ZO-1 and Occludin. The contents of IL-6, IL-17, IL-1β, and TNF-α in the intestinal tissues of mice were significantly reduced. Additionally, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were elevated. In contrast, the malondialdehyde (MDA) content decreased. Trypsin and pancreatic lipase activities in the ileum enhanced, and the SCFA contents such as acetic acid, propionic acid, and butyric acid in the colon increased. The study on intestinal flora revealed that RGO could enhance the abundance of intestinal flora and improve the flora structure. After RGO intervention, the relative abundance of Firmicutes, Lactobacillus, and Akkermania bacteria in the intestinal tract of mice increased compared with the model group, while that of Actinomycetes decreased. The intestinal microbiota structure changed to the case, with probiotics playing a dominant role. The correlation analysis indicated that Lactobacillus and Ackermann bacteria in the intestinal tract of mice were positively associated with SCFAs, Occludin, ZO-1, pancreatic amylase, SOD, and CAT activities. Moreover, they were negatively correlated with inflammatory factors IL-6, IL-17, IL-1β, and TNF-α.

Conclusions

RGO can decrease LPS-induced intestinal inflammation and intestinal barrier injury in mice and protect their intestinal function. RGO can ameliorate intestinal inflammation and maintain the intestinal barrier by regulating intestinal flora.