Trichinella spiralis: The influence of short chain fatty acids on the proliferation of lymphocytes, the goblet cell count and apoptosis in the mouse intestine

The potential prophylactic and therapeutic efficacy of progesterone and mifepristone on experimental trichinellosis with ultra-structural studies

Right up to now, there has not been an effective or safe therapy for trichinellosis. Thus, this study aimed to determine the efficacy of prophylactic and therapeutic regimens of progesterone and mifepristone on the intestinal and muscular phases of experimental Trichinella spiralis infection compared to albendazole. Seven distinct groups of mice were divided as follows: negative, positive, and drug control groups, as well as prophylactic and treatment groups using mifepristone and progesterone. Mice were sacrificed on the 7th and 37th days after infection. Treatment efficacy was evaluated using parasitological techniques, histopathological examination, immunohistochemical staining, and ultrastructural morphological analysis of adult worms by scanning electron microscopy. The mice groups received progesterone (300 ng/ml) and mifepristone (100 ng/ml). They demonstrated a significant improvement in intestinal and muscular inflammation and a statistically significant decline in the adult worm burden and encysted larvae (P < 0.001). Moreover, immunohistochemical staining of vascular endothelial growth factor and mucosal mast cell analyses were coincided with the obtained parasitological results. There was notable destruction and degeneration of the adult worm tegument by using both drugs. The current study pointed out that progesterone and mifepristone may provide new insights regarding the development of vaccines and drug protocols to treat trichinellosis through their combined action in reducing the inflammation, affecting the intestinal immune cell, and decreasing the adult worm burden, and larval capsule development.

The Role of Gut-derived Short-Chain Fatty Acids in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic condition affecting the central nervous system (CNS), where the interplay of genetic and environmental factors influences its pathophysiology, triggering immune responses and instigating inflammation. Contemporary research has been notably dedicated to investigating the contributions of gut microbiota and their metabolites in modulating inflammatory reactions within the CNS. Recent recognition of the gut microbiome and dietary patterns as environmental elements impacting MS development emphasizes the potential influence of small, ubiquitous molecules from microbiota, such as short-chain fatty acids (SCFAs). These molecules may serve as vital molecular signals or metabolic substances regulating host cellular metabolism in the intricate interplay between microbiota and the host. A current emphasis lies on optimizing the health-promoting attributes of colonic bacteria to mitigate urinary tract issues through dietary management. This review aims to spotlight recent investigations on the impact of SCFAs on immune cells pivotal in MS, the involvement of gut microbiota and SCFAs in MS development, and the considerable influence of probiotics on gastrointestinal disruptions in MS. Comprehending the gut-CNS connection holds promise for the development of innovative therapeutic approaches, particularly probiotic-based supplements, for managing MS.

Pumpkin seeds (Cucurbita pepo subsp. ovifera) decoction promotes Trichinella spiralis expulsion during intestinal phase via "Weep and Sweep" mechanism

Trichinosis is a zoonotic disease of communal health concern as it instigated human outbreaks in several countries. Besides, the development of resistance, traditional therapy has numerous antagonistic effects. Thereby, finding efficient natural alternatives is required. In comparison to albendazole, this study evaluated the impact of pumpkin decoction on Trichinella spiralis in experimentally infected mice. The anthelmintic action of pumpkin decoction (500 mg/kg) was determined using T. spiralis infected mice in enteric phase for 5 days. Pumpkin decoction anthelmintic activity fortified by mixing with honey (1:1). Pumpkin decoction and Pumpkin decoction-honey mixture were evaluated by comprising with reference drug, albendazole (50 mg/kg). The T. spiralis adult count was significantly lower in all treated groups, with the pumpkin decoction-honey mixture showing the largest reduction (83.2%) when compared to the infected group (P ≤ 0.001). The intestinal histological changes and the level of COX-2 expression in the intestinal tissue were both significantly reduced in the same group. The pumpkin decoction improved the immune response, as evidenced by a significant decrease in nitric oxide (NO) and tumor necrosis factor (TNF-α) and a significant increase in the expression of the transforming growth factor (TGF-1β) and interleukin-17 (IL-17). The pumpkin decoction's anthelmintic action was facilitated by the TGF-1β and IL-17-driven Weep and Sweep mechanism. Both administration of pumpkin decoction beside honey showed the best treatment group that resulted in high infection reduction besides amelioration of biochemical markers and restoration of histological to normal state. In conclusion, pumpkin decoction is highly effective against T. spiralis which could be a promising alternative herbal drug and the pumpkin decoction effect was higher in the case of combination with honey.

The Effects of Honeysuckle (Lonicera caerulea L.) Berry Iridoid-Anthocyanin Extract on the Intestinal and Muscle Histopathology in Mice during Experimental Trichinellosis

The aim of the study was to determine the effect of iridoid-anthocyanin extract from honeysuckle (Lonicera caerulea L.) (LC) berries on histopathological changes in the intestines and muscles during experimental trichinellosis in mice. The LC extract was administered to uninfected mice (LC group) and Trichinella-spiralis-infected mice (T+LC) orally at a dose of 2 g/kg bw, six times at 24 h intervals, from day 3 prior to infection to day 3 post-infection (dpi). Jejunum samples were collected on 5, 7, 14, and 21 dpi, and their histological assessment involved the villus height to crypt depth ratio (VH/CD), goblet cell (GC) number, and morphological changes. In the T. spiralis-infected muscles, the extent of inflammatory infiltration on the 14th and 21st dpi was assessed. LC in the infected mice restored the VH/CD ratio to control values on 14 dpi. A beneficial effect of the LC extract on the villus height was also observed 14 dpi in the LC and T+LC groups. No differences in the extent of inflammatory infiltration in the muscles between the T+LC and T groups were observed. In conclusion, the iridoid-anthocyanin extract from honeysuckle berry contributed to alleviating the symptoms of the intestinal phase of T. spiralis infection.

Treatment of pregnant mice with ABZ had no effect on the immune response of their offspring infected with Trichinella spiralis

Trichinellosis is a food-borne parasitic disease with a worldwide distribution that not only endangers human health but also leads to economic loss. Infection of pregnant animals with Trichinella spiralis (T. spiralis) may lead to abortion and other adverse consequences, so it is necessary to treat the infection during pregnancy. Albendazole (ABZ) is an effective therapeutic drug for adult T. spiralis worms. The safety of this drug during pregnancy, especially whether it has any effect on offspring, should be fully evaluated. A change in the immune response to T. spiralis in the offspring of pregnant mice treated with ABZ may lead to a difference in susceptibility to T. spiralis compared to that of the offspring of normal mice. However, the safety of ABZ treatment in pregnant mice and the effects on the immune response and susceptibility of their offspring to T. spiralis are poorly understood. Therefore, we assessed whether maternal ABZ treatment during pregnancy affects the immune response or susceptibility to T. spiralis in infected offspring. In this study, mice were infected with T. spiralis at 10 days of pregnancy and treated with ABZ at 3 days post infection (dpi), and the specific immune response in the pregnant mice and the survival rate and worm burden of their 6-week-old offspring after T. spiralis infection were examined. The results showed that the antiparasitic immune response in pregnant mice was activated by T. spiralis infection. Treatment of pregnant mice with ABZ increased the percentage of CD4 + T cells. The percentages of Th2 and Treg cells in the PP, MLN and spleen of pregnant mice in the infection group were significantly increased compared with those of normal mice. ABZ treatment during pregnancy promoted the Th2 and Treg immune responses in pregnant mice infected with T. spiralis. The transcriptional levels of the Th2 and Treg cytokines IL-4, IL-5, IL-13, and TGF-β in the small intestine, MLN and spleen of pregnant mice in the treatment group were significantly higher than those of pregnant mice in the T. spiralis infection only group. The results indicated that ABZ treatment did not cause abortion in pregnant mice or affect the survival rate of their offspring. Furthermore, treatment of pregnant mice with ABZ had no significant effect on the above immune responses in their T. spiralis-infected offspring compared to those of T. spiralis-infected offspring of mice in the normal group. The results also indicated that treatment of pregnant mice infected with T. spiralis with ABZ shifted the immune response to a Th2- and Treg-skewed immune response and that this drug had no effects on the offspring survival rate, immune response or worm burden after T. spiralis infection. This study further indicated that ABZ administration to treat T. spiralis infection in pregnant mice is safe for the select immune response and susceptibility of their offspring.

Regulation of short-chain fatty acids in the immune system

A growing body of research suggests that short-chain fatty acids (SCFAs), metabolites produced by intestinal symbiotic bacteria that ferment dietary fibers (DFs), play a crucial role in the health status of symbiotes. SCFAs act on a variety of cell types to regulate important biological processes, including host metabolism, intestinal function, and immune function. SCFAs also affect the function and fate of immune cells. This finding provides a new concept in immune metabolism and a better understanding of the regulatory role of SCFAs in the immune system, which impacts the prevention and treatment of disease. The mechanism by which SCFAs induce or regulate the immune response is becoming increasingly clear. This review summarizes the different mechanisms through which SCFAs act in cells. According to the latest research, the regulatory role of SCFAs in the innate immune system, including in NLRP3 inflammasomes, receptors of TLR family members, neutrophils, macrophages, natural killer cells, eosinophils, basophils and innate lymphocyte subsets, is emphasized. The regulatory role of SCFAs in the adaptive immune system, including in T-cell subsets, B cells, and plasma cells, is also highlighted. In addition, we discuss the role that SCFAs play in regulating allergic airway inflammation, colitis, and osteoporosis by influencing the immune system. These findings provide evidence for determining treatment options based on metabolic regulation.

Short chain fatty acids, a possible treatment option for autoimmune diseases

Gut microbiota can interact with the immune system through its metabolites. Short-chain fatty acids (SCFAs), as one of the most abundant metabolites of the resident gut microbiota play an important role in this crosstalk. SCFAs (acetate, propionate, and butyrate) regulate nearly every type of immune cell in the gut's immune cell repertoire regarding their development and function. SCFAs work through several pathways to impose protection towards colonic health and against local or systemic inflammation. Additionally, SCFAs play a role in the regulation of immune or non-immune pathways that can slow the development of autoimmunity either systematically or in situ. The present study aims to summarize the current knowledge on the immunomodulatory roles of SCFAs and the association between the SCFAs and autoimmune disorders such as celiac disease (CD), inflammatory bowel disease (IBD), rheumatoid arthritis (RA), multiple sclerosis (MS), systemic lupus erythematosus (SLE), type 1 diabetes (T1D) and other immune-mediated diseases, uncovering a brand-new therapeutic possibility to prevent or treat autoimmunity.

Therapeutic efficacy of albendazole and berberine loaded on bovine serum albumin nanoparticles on intestinal and muscular phases of experimental trichinellosis

There has been no treatment for trichinellosis until now. Therefore, this work targeted to investigating the efficacy of albendazole and berberine alone and loaded on bovine serum albumin (BSA) nanoparticles against intestinal and muscular phases of trichinellosis in mice. Mice were divided into nine different groups: negative control, positive control, blank nanoparticle, albendazole, berberine, a combination of albendazole and berberine, albendazole-loaded nanoparticle, berberine-loaded nanoparticle and combination of albendazole and berberine-loaded nanoparticle. Subsequently, they were sacrificed 6 and 35 days after infection. Treatment efficacies were parasitologically, histopathologically and, immunohistochemically assessed. Parasitological counting for the adult worms and encysted larvae with histopathological assessment using H&E for intestinal and muscular sections and picrosirius red stain for muscular sections were used. Also, immunohistochemical expression of the intestinal nod-like receptor-pyrin domain containing 3 (NLRP3) was investigated. The group treated with nano_combined drugs showed a statistically significant reduction in adult and encysted larval count (p<0.005), a remarkable improvement of intestinal and muscular inflammation, and a reduction in the capsular thickness of the larvae. Also, this group showed the highest reduction of NLRP3 expression. This work revealed that berberine might be a promising anti-trichinellosis drug with a synergistic effect when combined with albendazole through modulation of the immune response, inflammation, and larva capsule formation. Furthermore, delivering both drugs in a nanoparticle form improves their therapeutic response.

Aging-Accelerated Mouse Prone 8 (SAMP8) Mice Experiment and Network Pharmacological Analysis of Aged Liupao Tea Aqueous Extract in Delaying the Decline Changes of the Body

Aging and metabolic disorders feedback and promote each other and are closely related to the occurrence and development of cardiovascular disease, type 2 diabetes, neurodegeneration and other degenerative diseases. Liupao tea is a geographical indication product of Chinese dark tea, with a “red, concentrated, aged and mellow” flavor quality. In this study, the aqueous extract of aged Liupao tea (ALPT) administered by continuous gavage significantly inhibited the increase of visceral fat and damage to the intestinal–liver–microbial axis in high-fat modeling of SAMP8 (P8+HFD) mice. Its potential mechanism is that ALPT significantly inhibited the inflammation and aggregation formation pathway caused by P8+HFD, increased the abundance of short-chain fatty acid producing bacteria Alistipes, Alloprevotella and Bacteroides, and had a calorie restriction effect. The results of the whole target metabolome network pharmacological analysis showed that there were 139 potential active components in the ALPT aqueous extract, and the core targets of their actions were SRC, TP53, AKT1, MAPK3, VEGFA, EP300, EGFR, HSP90AA1, CASP3, etc. These target genes were mainly enriched in cancer, neurodegenerative diseases, glucose and lipid metabolism and other pathways of degenerative changes. Molecular docking further verified the reliability of network pharmacology. The above results indicate that Liupao tea can effectively delay the body’s degenerative changes through various mechanisms and multi-target effects. This study revealed that dark tea such as Liupao tea has significant drinking value in a modern and aging society.

Increased Proportion of Fiber-Degrading Microbes and Enhanced Cecum Development Jointly Promote Host To Digest Appropriate High-Fiber Diets

Previous study found that appropriate high-fiber diet (containing 19.10% total dietary fiber [TDF], treatment II) did not reduce apparent fiber digestibility of Chinese Suhuai finishing pigs and increased the yield of short-chain fatty acids (SCFAs), but too high-fiber diet (containing 24.11% TDF, treatment IV) significantly reduced apparent fiber digestibility compared with normal diet (containing 16.70% TDF, control group). However, characteristics of microbiota at the species level and histological structure in pigs with the ability to digest appropriate high-fiber diets were still unknown. This study conducted comparative analysis of cecal physiology and microbial populations colonizing cecal mucosa. The results showed intestinal development indexes including cecum length, densities of cecal goblet cells, and renewal of cecal epithelial cells in treatment II and IV had better performance than those in the control. Paludibacter jiangxiensis, Coprobacter fastidiosus, Bacteroides coprocola CAG:162, Bacteroides barnesiae, and Parabacteroides merdae enriched in treatment II expressed large number of glycoside hydrolase (GH)-encoding genes and had the largest number of GH families. In addition, pathogenic bacteria (Shigella sonnei, Mannheimia haemolytica, and Helicobacter felis) were enriched in treatment IV. Correlation analysis revealed that the intestinal development index positively correlated with the relative abundance of cecal mucosal microbiota and the amount of digested fiber. These results indicated that increased proportions of fiber-degrading microbes and enhanced intestinal development jointly promote the host to digest an appropriate high-fiber diet. However, although too-high fiber levels in diet could maintain the adaptive development of cecal epithelium, the proportions of pathogenic bacteria increased, which might lead to a decrease of fiber digestion in pigs. IMPORTANCE Although studies about the effects of dietary fiber on fiber digestion and intestinal microbiota of pigs were widely in progress, few studies have been conducted on the dynamic response of intestinal microbiota to dietary fiber levels, and the characteristics of intestinal microbiota and intestinal epithelial development adapted to high-fiber diet s were still unclear. Appropriate high fiber promoted the thickness of large intestine wall, increased the density of cecal goblet cells, and promoted the renewal of cecal epithelial cells. In addition, appropriate high fiber improves the microbial abundance with fiber-digesting potential. However, excessive dietary fiber caused an increase in the abundance of pathogenic bacteria. These results indicated that an increased proportion of fiber-degrading microbes and enhanced intestinal development jointly promote host to digest appropriate high-fiber diets. However, although too-high fiber levels in diet could maintain the adaptive development of cecal epithelium, the proportions of pathogenic bacteria increased, which might lead to a decrease of fiber digestion in pigs. Our data provided a theoretical basis for rational and efficient utilization of unconventional feed resources in pig production.

A potential herbal therapeutic for trichinellosis

Background

Trichinellosis is a helminthic disease caused by Trichinella spiralis via the ingestion of raw or undercooked meat of infected animals. Current estimates indicate that 11 million humans have trichinellosis, worldwide. The effective use of anti-trichinella medications is limited by side effects and resistance which highlight the critical need for safe and effective drugs, particularly those derived from medicinal plants. Therefore, in the present study, we aimed to evaluate the efficacy of the ethanolic extract of Artemisia annua (A. annua) in treatment of experimentally induced trichinellosis.

Materials and methods

Trichinellosis was induced experimentally in male 6–8 weeks BALB/c mice. BALB/c mice were divided into four groups, 10 mice each. One group was left uninfected and untreated, whereas three groups were infected with T. spiralis. One infected group of mice was left untreated (negative control) while the remaining two infected groups received either 300 mg/kg of the ethanolic extract of A. annua or 50 mg/kg of albendazole (positive control). All treatments started from the third day post-infection (dpi) for 3 successive days. All animals were sacrificed on the 7th dpi for evaluation of treatment efficacy.

Results

Our findings showed that A. annua treatment reduced the T. spiralis adult-worm count in the intestine of infected animals. Moreover, treatment with A. annua restored the normal intestinal architecture, reduced edema, alleviated inflammation as demonstrated by reduced inflammatory infiltrate and expression of TGF-β in intestinal tissues of A. annua-treated animals compared to infected untreated animals.

Conclusions

Our findings show that A. annua extract is effective in treating experimentally induced trichinellosis which highlight the therapeutic potential of A. annua for intestinal trichinellosis.

Oscillospira - a candidate for the next-generation probiotics

Oscillospira is a class of organism that often appears in high-throughput sequencing data but has not been purely cultured and is widely present in the animal and human intestines. There is a strong association between variation in Oscillospira abundance and obesity, leanness, and human health. In addition, a growing body of studies has shown that Oscillospira is also implicated in other diseases, such as gallstones and chronic constipation, and has shown some correlation with the positive or negative changes in its course. Sequencing data combined with metabolic profiling indicate that Oscillospira is likely to be a genus capable of producing short-chain fatty acids (SCFAs) such as butyrate, which is an important reference indicator for screening "next-generation probiotics ". Considering the positive effects of Oscillospira in some specific diseases, such as obesity-related metabolic diseases, it has already been characterized as one of the next-generation probiotic candidates and therefore has great potential for development and application in the future food, health care, and biopharmaceutical products.

The Aged Intestine: Performance and Rejuvenation

Owing to the growing elderly population, age-related problems are gaining increasing attention from the scientific community. With senescence, the intestine undergoes a spectrum of changes and infirmities that are likely the causes of overall aging. Therefore, identification of the aged intestine and the search for novel strategies to rescue it, are required. Although progress has been made in research on some components of the aged intestine, such as intestinal stem cells, the comprehensive understanding of intestinal aging is still limited, and this restricts the in-depth search for efficient strategies. In this concise review, we discuss several aspects of intestinal aging. More emphasis is placed on the appraisal of current and potential strategies to alleviate intestinal aging, as well as future targets to rejuvenate the aged intestine.

Herbal therapy for ameliorating nonalcoholic fatty liver disease via rebuilding the intestinal microecology

The worldwide prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing, and this metabolic disorder has been recognized as a severe threat to human health. A variety of chemical drugs have been approved for treating NAFLD, however, they always has serious side effects. Chinese herbal medicines (CHMs) have been widely used for preventing and treating a range of metabolic diseases with satisfactory safety and effective performance in clinical treatment of NAFLD. Recent studies indicated that imbanlance of the intestinal microbiota was closely associated with the occurrence and development of NAFLD, thus, the intestinal microbiota has been recognized as a promising target for treatment of NAFLD. In recent decades, a variety of CHMs have been reported to effectively prevent or treat NAFLD by modulating intestinal microbiota to further interfer the gut-liver axis. In this review, recent advances in CHMs for the treatment of NAFLD via rebuilding the intestinal microecology were systematically reviewed. The key roles of CHMs in the regulation of gut microbiota and the gut-liver axis along with their mechanisms (such as modulating intestinal permeability, reducing the inflammatory response, protecting liver cells, improving lipid metabolism, and modulating nuclear receptors), were well summarized. All the knowledge and information presented here will be very helpful for researchers to better understand the applications and mechanisms of CHMs for treatment of NAFLD.

Effects of co-fermented collagen peptide-jackfruit juice on the immune response and gut microbiota in immunosuppressed mice

Recently, the development of fermented foods for ameliorating immunity and gut microbiota has attracted extensive attention. In this study, co-fermented collagen peptide-jackfruit juice was used in immunosuppressed mice to evaluate the immune response and gut microbiota modulatoration. The results showed that co-fermented peptide-jackfruit juice (FPJ) increased anti-oxidant capacity and lactic acid content. FPJ significantly promoted the immune organ (spleen and thymus) indexes, alleviated the injuries of colon tissue and stimulated the secretion of cytokines and immunoglobulins (IgA, IgM, IgG) (P < 0.05). Moreover, FPJ significantly upregulated the gene expression of TNF-α, IL-4, IFN-γ, IL-2, IL-10, T-bet, Foxp3, RORγ and GATA3. Furthermore, FPJ improved gut microbiota composition and elevated the short-chain fatty acids (SCFAs) concentration. The relative abundances of pathogenic bacteria decreased while beneficial bacteria increased after administration FPJ. These findings suggested that FPJ could be developed as a promising functional food for immunomodulation.

Fermentation and Metabolism of Dietary Protein by Intestinal Microorganisms

Dietary protein is linked to the intestinal microorganisms. The decomposition of dietary protein can provide nutrients for microbial growth, which in turn can ferment protein to produce some metabolites. This review elaborates that the effects of different protein levels and types on intestinal microorganisms and their metabolites fermented by intestinal microorganisms, as well as the effects of these metabolites on organisms. It is well known that intestinal microbial imbalance can cause some diseases. Dietary protein supplementation can alter the composition of intestinal microorganisms and thus regulates the body health. However, protein can also produce some harmful metabolites. Therefore, how to rationally supplement protein is particularly important.

Control of lymphocyte functions by gut microbiota-derived short-chain fatty acids

A mounting body of evidence indicates that dietary fiber (DF) metabolites produced by commensal bacteria play essential roles in balancing the immune system. DF, considered nonessential nutrients in the past, is now considered to be necessary to maintain adequate levels of immunity and suppress inflammatory and allergic responses. Short-chain fatty acids (SCFAs), such as acetate, propionate, and butyrate, are the major DF metabolites and mostly produced by specialized commensal bacteria that are capable of breaking down DF into simpler saccharides and further metabolizing the saccharides into SCFAs. SCFAs act on many cell types to regulate a number of important biological processes, including host metabolism, intestinal functions, and immunity system. This review specifically highlights the regulatory functions of DF and SCFAs in the immune system with a focus on major innate and adaptive lymphocytes. Current information regarding how SCFAs regulate innate lymphoid cells, T helper cells, cytotoxic T cells, and B cells and how these functions impact immunity, inflammation, and allergic responses are discussed.

L. johnsonii, L. plantarum, and L. rhamnosus alleviated Enterohaemorrhagic Escherichia coli-induced diarrhoea in mice by regulating gut microbiota

Enterohaemorrhagic Escherichia coli (EHEC) is a prominent foodborne pathogen that causes infectious intestinal diarrhoea. Lactobacillus is a recognized probiotic that inhibits intestinal pathogens and maintains the balance of the intestinal flora. The purpose of this study was to investigate the regulatory effects of three Lactobacillus strains, L. johnsonii, L. plantarum, and L. rhamnosus, on the intestinal flora of EHEC-infected mice. The initial weight and diarrhoea index of the mice were recorded. After 21 days, the faeces of the mice were subjected to 16S rDNA high-throughput sequencing. The diarrhoea index of mice treated with Lactobacillus improved, their body weight continued to rise, and their liver index gradually decreased. The α diversity analysis showed that the intestinal flora diversity and abundance were lower in mice infected with EHEC than in healthy mice. L. plantarum, L. johnsonii, and L. rhamnosus significantly improved the diversity of the flora species. In terms of flora composition, the three main phyla present were Bacteroidetes, Firmicutes, and Proteobacteria. The abundance of these three phyla was reduced to 93.81% after infection and restored to over 96.30% after treatment. At the genus level, Lactobacillus reduced the abundance of Bacteroides, Helicobacter pylori, and Shigella, while increasing the abundance of butyric acid-producing bacteria and Lactobacillus. Finally, a heat map and non-metric multidimensional scaling analysis showed that the intestinal flora structures in the L. johnsonii, L. plantarum, and L. rhamnosus treatment groups were closest to those of healthy mice. In conclusion, L. johnsonii, L. plantarum, and L. rhamnosus regulated and improved the structure of intestinal flora and relieved diarrhoea caused by EHEC infection.

Dose-dependent effects of lead induced gut injuries: An in vitro and in vivo study

Lead (Pb) toxicity has been widely studied, but its dose-dependent toxic effects on the gut remain unclear, therefore, the aim of this study was to evaluate the effects of different doses of Pb exposure on the gut microbiota and gut barrier in vitro and in vivo. The HT-29 cell model was used to determine the Pb-induced effects on cell viability, reactive oxygen species (ROS), and tight junction proteins (TJPs) in vitro, and C57BL/6 mice models exposed to 0, 20, 100, 500, and 1000 mg/kg Pb were used to investigate the Pb-induced dose-dependent effects on the gut microbiota, TJP expression, and colon histopathology. Our results showed that the exposure of HT-29 cells to 8 mM Pb decreased cell viability by 50%, elevated ROS levels by 200%, and suppressed the expression of the TJPs, zonula occludens-1 (ZO-1) and occludin by 23% and 35%, respectively. Consistently, Pb-exposed mice showed significant increases in colon tissue damage and inflammation and reductions in ZO-1 mRNA levels in a dose-dependent manner. The occludin mRNA levels decreased in the 500 and 1000 mg/kg groups. At the genus level, the relative abundance of Coprococcus and Oscillospira decreased and that of Lactobacillus increased in linear manner with the Pb exposure dose. PICRUSt analysis based on 16S rRNA sequencing revealed Pb dose-dependent alterations in metabolism through the gut microbiota. These findings suggest that Pb exposure can not only disrupt the barrier by generating oxidative stress, but can also induce gut dysbiosis, colon tissue damage, and gut inflammation in a dose-dependent manner.

Tilapia head glycolipids reduce inflammation by regulating the gut microbiota in dextran sulphate sodium-induced colitis mice

In this study, we evaluated the effects of tilapia head glycolipids (TH-GLs) on male C57BL/6 mice with inflammatory bowel disease (IBD) induced by dextran sulfate sodium (DSS) and the changes in gut microbiota compared with sulfasalazine. Mice were orally treated with 3% (w/v) DSS or not for 7 days, followed by drug treatment with TH-GLs or sulfasalazine. After treatment, macroscopic colitis symptoms, intestinal epithelial barrier function, inflammatory cytokines, and gut microbiota homeostasis were assessed. Further studies showed that TH-GLs and sulfasalazine showed different influences on the gut microbiota structure. Both sulfasalazine and TH-GLs decreased the DSS-induced enrichment of Gammaproteobacteria and Enterobacteriaceae. However, TH-GLs had a selective increase in the enrichment of Akkermansia, Prevotellaceae, Oscillospira, Allobaculum, Bifidobacterium, and Coprococcus in contrast to sulfasalazine, which selectively increased the enrichment of Dorea, Turicibacter, Bacteroides, Coprobacillus, Mucispirillum, and Dehalobacterium. In addition, both TH-GLs and sulfasalazine relieved body weight loss, and increased the immune organ index, while maintaining the balance between pro-inflammatory and anti-inflammatory cytokines. The results indicate that TH-GLs alleviate DSS-induced IBD in mice by decreasing the abundance of harmful gut microbiota and enhancing the abundance of probiotic gut microbiota. Thus, the mechanism through which TH-GLs inhibit inflammation through gut microbiota is different from that of sulfasalazine. Therefore, TH-GLs stand as potential prebiotics for the treatment of colonic inflammation and related diseases.

Exposure time determines the protective effect of Trichinella spiralis on experimental colitis

Several studies demonstrate the protective effect of Trichinella spiralis (T. spiralis) on autoimmune diseases, however the optimal exposure time remains unexplored. This study aimed to determine whether pre-exposure of mice to T. spiralis conferred greater protection than introduction of the parasite in the acute phase of experimental colitis. We compared the effect of T. spiralis on dextran sodium sulfate (DSS)-induced colitis using two exposure paradigms: introduction three weeks prior to, or immediately after the induction period. Inflammation scores, morphological changes and cytokine profiles in serum and colonic tissue were assessed. At a parasite dose of 300 cysts, post exposure had a more pronounced effect on cytokine profiles, improved gross appearance of colon tissue, and reduced inflammatory symptoms. In addition, we demonstrate that regardless of cyst number, pre-exposure to T. spiralis did not confer protective benefits when compared to parasite introduction in the acute phase of DSS-induced colitis. Moreover, our data indicates that the underlying mechanisms of action involve an IL-17/TNF-alpha synergistic reaction, suppression of Th1 and Th2 responses, and an upregulation of the regulatory cytokines IL-10 and TGF-beta 1. Our results demonstrate that moderate exposure to T. spiralis in the acute phase of DSS-induced colitis improves disease associated inflammation and tissue disruption.

The Short-Chain Fatty Acid Acetate in Body Weight Control and Insulin Sensitivity

The interplay of gut microbiota, host metabolism, and metabolic health has gained increased attention. Gut microbiota may play a regulatory role in gastrointestinal health, substrate metabolism, and peripheral tissues including adipose tissue, skeletal muscle, liver, and pancreas via its metabolites short-chain fatty acids (SCFA). Animal and human data demonstrated that, in particular, acetate beneficially affects host energy and substrate metabolism via secretion of the gut hormones like glucagon-like peptide-1 and peptide YY, which, thereby, affects appetite, via a reduction in whole-body lipolysis, systemic pro-inflammatory cytokine levels, and via an increase in energy expenditure and fat oxidation. Thus, potential therapies to increase gut microbial fermentation and acetate production have been under vigorous scientific scrutiny. In this review, the relevance of the colonically and systemically most abundant SCFA acetate and its effects on the previously mentioned tissues will be discussed in relation to body weight control and glucose homeostasis. We discuss in detail the differential effects of oral acetate administration (vinegar intake), colonic acetate infusions, acetogenic fiber, and acetogenic probiotic administrations as approaches to combat obesity and comorbidities. Notably, human data are scarce, which highlights the necessity for further human research to investigate acetate’s role in host physiology, metabolic, and cardiovascular health.

Short-chain fatty acid delivery: assessing exogenous administration of the microbiome metabolite acetate in mice

Short-chain fatty acids (SCFAs) are fermentation by-products of gut microbes which have been linked to positive effects on host physiology; the most abundant SCFA is acetate. Exogenous administration of acetate alters host metabolism, immune function, and blood pressure, making it a biologic of interest. The effects of acetate have been attributed to activation of G-protein-coupled receptors and other proteins (i.e., HDACs), often occurring at locations distant from the gut such as the pancreas or the kidney. However, due to technical difficulties and costs, studies have often delivered exogenous acetate without determining if systemic plasma acetate levels are altered. Thus, it is unclear to what extent each method of acetate delivery may alter systemic plasma acetate levels. In this study, we aimed to determine if acetate is elevated after exogenous administration by drinking water (DW), oral gavage (OG), or intraperitoneal (IP) injection, and if so, over what timecourse, to best inform future studies. Using a commercially available kit, we demonstrated that sodium acetate delivered over 21 days in DW does not elicit a measurable change in systemic acetate over baseline. However, when acetate is delivered by OG or IP injection, there are rapid, reproducible, and dose-dependent changes in plasma acetate. These studies report, for the first time, the timecourse of changes in plasma acetate following acetate administration by three common methods, and thus inform the best practices for exogenous acetate delivery.

Immune Cell Responses and Cytokine Profile in Intestines of Mice Infected with Trichinella spiralis

The intestinal phase is critical for trichinellosis caused by Trichinella spiralis (T. spiralis), as it determines both process and consequences of the disease. Several previous studies have reported that T. spiralis induces the initial predominance of a Th1 response during the intestine stage and a subsequent predominance of a Th2 response during the muscle stage. In the present study, immune cells and cytokine profile were investigated in the intestine of mice infected with T. spiralis. The results showed that the number of eosinophils, goblet cells, mucosal mast cells, and 33D1+ dendritic cells (DCs) increased during the intestinal phase of the infection. Among these, eosinophils, goblet cells, and mucosal mast cells continued to increase until 17 days post infection (dpi), and the number of 33D1+ DCs increased compared to wild type; however, it did not change with the days of infection. The mRNA and protein levels of Th1 cytokines IL-2, IL-12, and IFN-γ and the Th2 cytokines IL-4, IL-5, IL-10, IL-13, and TGF-β were all increased in the tissues of the small intestine in infected mice; however, in general, Th2 cytokines increased more than Th1 cytokines. In conclusion, our findings suggest that T. spiralis infection can induce an increase of small intestine mucosal immune cells and add further evidence to show that the intestinal mucosal immune system of infected mice was induced toward mixed Th1/Th2 phenotypes with the predominance of Th2 response at the early stage of infection.

Arabinoxylan in wheat is more responsible than cellulose for promoting intestinal barrier function in weaned male piglets

BACKGROUND

The effect of dietary fiber on intestinal function primarily has been ascribed to its interaction with intestinal bacteria in the hindgut, whereas changes in intestinal bacteria in the host have been considered to depend on fiber composition.

OBJECTIVES

The objectives of this study were to determine the contribution of the major fiber components to the health-promoting effects of wheat bran on intestinal mucosal barrier function and to elucidate the involvement of microbiota changes in weaned piglets.

METHODS

Thirty freshly weaned male piglets were assigned to 5 dietary treatment groups (n = 6) according to litter and weight. The piglets consumed synthetic diets ad libitum for 30 d, including a basal control diet (CON) without fiber components, a wheat bran diet (WB) as reference diet (10% wheat bran), and 3 other diets containing amounts of fiber components equivalent to those in the WB, i.e., an arabinoxylan diet (AX), a cellulose diet (CEL), and a combined arabinoxylan and cellulose diet (CB).

RESULTS

The groups consuming diets containing arabinoxylans (i.e., the WB, AX, and CB groups) had increased intestinal secretory immunoglobulin A concentrations, goblet cell number and cecal short-chain fatty acid concentrations, and reduced branched-chain fatty acid concentrations and pH values compared with the CON group. In the WB group, the stimulated secretion of Cl(-) was suppressed (60.8% and 47.5% change in short-circuit current caused by theophylline and carbachol, respectively) in the distal small intestine compared with the CON group. The AX and CB groups also had increased intestinal alkaline phosphatase activities and reduced intestinal transcellular permeability (by 77.3% and 67.2%, respectively) compared with the CON group. Meanwhile, in the WB group, cecal Bacteroidetes and Enterobacteriaceae populations were lower, and the growth of Lactobacillus was higher in the AX and CB groups than in the CON group, whereas no positive effect on intestinal barrier function was observed in the CEL group.

CONCLUSION

Arabinoxylan in wheat bran, and not cellulose, is mainly responsible for improving various functional components of the intestinal barrier function and the involvement of microbiota changes.