Cecal Contents Research Articles

Ishimozuku (Sphaerotrichia firma) lipids containing fucoxanthin suppress fatty liver and improve short chain fatty acid production in obese model mice

Ishimozuku (Sphaerotrichia firma) is one species of edible brown algae in Japan. The lipids contain rich of fucoxanthin and n-3 unsaturated fatty acids. This study analyzed dietary Ishimozuku lipid components and the effects on fatty liver and intestinal metabolite component production in obese model mice. Fatty acid composition and fucoxanthin contents of Ishimozuku lipids were analyzed by gas chromatography (GC) and high performance liquid chromatography (HPLC) analysis. Ishimozuku lipids contained fucoxanthin about 44.71 ± 0.02 mg/g. KK-Ay mice were fed with high-fat diet (Control) and a high-fat diet + 0.5% Ishimozuku lipid diet (Ishimozuku) for 4 weeks. Liver triglyceride contents and serum triglyceride concentrations were significantly lower in the Ishimozuku group than in the Control group. Results show that acetyl-CoA carboxylase (ACC) and stearoyl-CoA desaturase (SCD-1) mRNA expression were suppressed in the livers of Ishimozuku group mice. Furthermore, short chain fatty acid amounts in the cecal contents were greater in the Ishimozuku group mice. These results suggest that dietary Ishimozuku lipid components suppress liver lipid accumulation. Results also indicate Ishimozuku lipid components improve the balance of the intestinal microflora, which is disturbed by a high fat diet, and which promotes short chain fatty acid accumulation in the intestine. That accumulation is related to lipid and glucose metabolism.

Draft genome sequences of Campylobacter species isolated from the cecal contents of broiler chickens.

Here, we report the draft genomes of 10 Campylobacter strains isolated from the cecal contents of market-age broiler chickens naturally colonized with Campylobacter. Through a comprehensive analysis of these draft genomes, we have unveiled their core genetic elements and several antimicrobial resistance genes.

Dietary novel alkaline protease from Bacillus licheniformis improves broiler meat nutritional value and modulates intestinal microbiota and metabolites

BackgroundDifferent types of exogenous protease supplements have a positive impact on animal performance, but their effects on the nutritional value of meat and the gut microbial community of broilers have not been extensively studied. The objective of this investigation was to determine the impact of supplementation with a novel alkaline protease derived from Bacillus licheniformis (at doses of 0, 100, 200, 300, and 400 g/t) on the fatty acid and amino acid profiles, inosine monophosphate (IMP) levels, total volatile basic nitrogen (TVB-N) content found within the breast muscle, as well as the impact on the cecal microbiota and metabolites.ResultsSupplementation with 200–400 g/t of the novel protease resulted in a significant elevation in the concentration of essential amino acids (P < 0.001), flavor amino acids (P < 0.001), and total protein (P = 0.013) within the breast muscle. Results derived from the 16S rRNA sequencing and untargeted metabolomics analysis of the cecal content revealed that the novel protease reshaped the cecal microbial and metabolite profiles. In particular, it led to increased relative abundances of Bacteroides, Lactobacillus, Alistipes, and Eubacterium, while simultaneously causing a reduction in the metabolites of D-lactic acid and malonic acid. Moreover, correlation analyses unveiled significant relationships between distinct microbes and metabolites with the contents of IMP, fatty acids, and amino acids in the broiler's breast muscle.ConclusionIn summary, the novel protease regulated the intestinal microbial community and metabolism, thereby inducing changes in the compositions of fatty acids and amino acids profiles, as well as IMP levels in broiler meat. These alterations significantly contributed to the enhancement of the nutritional value and flavor of the meat.Graphical abstract

Comparison of the effects of alfalfa meal and sorghum distillery residue supplementation on the methane emissions in black-feathered Taiwan native chicken.

The issue of global warming, primarily fueled by anthropogenic greenhouse gas emissions, necessitates effective strategies to address methane (CH4) emissions from both ruminants and nonruminants. Drawing inspiration from successful approaches employed in ruminants, this study evaluates the impact of supplementing the diets of Taiwan's native black-feathered chickens with alfalfa meal and sorghum distillery residues (SDRs) on CH4 emissions. Using a respiration chamber the results reveal a significant reduction in CH4 emissions when incorporating either 30% alfalfa meal or 30% SDRs into the chicken diet, demonstrating a 59% and 49% decrease, respectively, compared to the control group (P < 0.05). Considering that alfalfa meal contains saponins and SDRs contain tannins, the study delves into the mechanism through which these components mitigate CH4 production in chickens. Incorporating saponins or tannins shows that groups supplemented with these components exhibit significantly lower CH4 emissions compared to the control group (P < 0.05), with a consistent linear decrease as the concentration of the feed additive increases. Further in vitro analysis of chicken cecal contents indicates a proportional reduction in CH4 production with increasing levels of added saponins or tannins (P < 0.05). These findings suggest that the CH4-reducing effects of alfalfa meal and SDRs can be attributed to their saponins and tannin content. However, caution is warranted as excessive alfalfa meal supplementation may adversely impact poultry growth. Consequently, sorghum distillery residue emerges as a more suitable feed ingredient for mitigating CH4 emissions in Taiwan's native black-feathered chickens compared to alfalfa. Additionally, substituting SDRs for conventional commercial chicken feed not only reduces CH4 emissions but also enhances the utilization of byproducts.

Resistance of Lactobacillus Sp. SKG 34 in The Digestive Tract of Rats Detected Using Random Amplified Polymorphic DNA Technique

In recent years, interest in probiotics, particularly Lactobacillus strains like Lactobacillus sp. SKG34, isolated from Sumbawa mare milk, has surged due to their potential health benefits. This strain holds promise as a probiotic agent, but understanding its behavior in the gastrointestinal (GI) tract is essential for effective application. This study aimed to investigate the resistance and persistence of Lactobacillus sp. SKG34 in the GI tract of rats. Rats were orally administered the strain at a concentration of 10^8 cells for 30 days. The probiotic’s ability to modulate gut microbiota and improve host health is a key area of interest. By utilizing techniques like PCR-RAPD, this research sought to elucidate the fate of Lactobacillus sp. SKG34 in the complex environment of the rat GI tract. Results revealed a significant increase in LAB population in cecal contents, from 3.06 x 10^9 cfu/g in the control group to 1.25 x 10^10 cfu/g in the probiotic group. RAPD analysis also detected Lactobacillus sp. SKG34 in approximately 23% of the total population of lactic acid bacteria in cecal contents, indicating its resistance and proliferation within the GI tract. Further investigation is warranted to fully understand the potential of Lactobacillus sp. SKG34 as a beneficial probiotic strain for human application.

Effect of shipping on the microbiome of donor mice used to reconstitute germ-free recipients.

The gut microbiota (GM) influences multiple processes during host development and maintenance. To study these events, fecal microbiota transfer (FMT) to germ-free (GF) recipients is often performed. Mouse models of disease are also susceptible to GM-dependent effects, and cryo-repositories often store feces from donated mouse strains. Shipping live mice may affect the GM and result in an inaccurate representation of the baseline GM. We hypothesize that the use of such fecal samples for FMT would transfer shipping-induced changes in the donor GM to GF recipients. To test this, donor mice originating from two suppliers were shipped to the University of Missouri. Fecal samples collected pre- and post-shipping were used to inoculate GF mice. Pre- and post-shipping fecal samples from donors, and fecal and/or cecal contents were collected from recipients at one and two weeks post-FMT. 16S rRNA sequencing revealed supplier-dependent effects of shipping on the donor microbiome. FMT efficiency was independent of shipping timepoint or supplier, resulting in transmission of shipping-induced changes to recipient mice, however the effect of supplier-origin microbiome remained evident. While shipping may cause subtle changes in fecal samples collected for FMT, such effects are inconsistent among supplier-origin GMs and minor in comparison to other biological variables.

Inulin alleviates atherosclerosis through improving lipid metabolism, inflammation, and gut microbiota in ApoE-knockout mice: the short-chain is more efficacious.

Atherosclerosis (AS) is considered the underlying cause of many diseases, particularly cardiovascular and cerebrovascular diseases. Inulin, a type of fructan, has shown potential in improving atherosclerosis, although there are conflicting findings. It is hypothesized that the polymerization degree of inulin may largely influence its therapeutic effectiveness. Therefore, this study aimed to investigate the effects and mechanisms of short-chain and long-chain inulin in AS. ApoE-/- mice fed a high fat diet (HFD) were used to establish an atherosclerosis model. These mice received daily oral administration of either short-chain or long-chain inulin for 12weeks. Plasma lipid metabolism-related indices were measured using biochemical analysis, and plasma immunological indices were analyzed via ELISA. The aorta, aortic root regions, liver tissue, adipose tissue, and colon tissue were examined through various staining techniques, including ORO staining, hematoxylin and eosin staining, Alcian blue staining, and immunofluorescent or immunohistochemical assays. Microbiome analysis was conducted in the cecal content. The results indicated that both short-chain and long-chain inulin substantially reduced the formation of atherosclerotic plaques. Inulin also improved plasma lipid concentrations and hepatic lipid metabolism, and partially alleviated both localized (atherosclerotic lesions) and systemic inflammation. Short-chain inulin was more effective than long-chain inulin in reducing atherosclerotic plaques formation, enhancing lipid metabolism and reducing inflammation. Additionally, both types of inulin showed similar effectiveness in enhancing intestinal epithelial barrier integrity, gut microbiota composition and functionality. These findings suggest that inulin has a protective role against atherosclerosis by enhancing lipid metabolism, reducing inflammation, and improving intestinal barrier and gut microbiota. As a dietary intervention, short-chain inulin is more effective than long-chain inulin, offering clinical implications for using inulin as a therapeutic agent for atherosclerosis.

Impact of maternal Bifidobacterium breve M-16V and scGOS/lcFOS supplementation during pregnancy and lactation on the maternal immune system and milk composition.

Maternal synbiotic supplementation during pregnancy and lactation can significantly influence the immune system. Prebiotics and probiotics have a positive impact on the immune system by preventing or ameliorating among others intestinal disorders. This study focused on the immunomodulatory effects of B. breve M-16V and short chain galacto-oligosaccharides (scGOS)/long chain fructo-oligosachairdes (lcFOS), including systemic and mucosal compartments and milk composition. Lewis rats were orally administered with the synbiotic or vehicle during pregnancy (21 days) and lactation (21 days). At the weaning day, small intestine (SI), mammary gland (MG), adipose tissue, milk, mesenteric lymph nodes (MLN), salivary gland (SG), feces and cecal content were collected from the mothers. The immunoglobulinome profile showed increased IgG2c in plasma and milk, as well as elevated sIgA in feces at weaning. The supplementation improved lipid metabolism through enhanced brown adipose tissue activity and reinforced the intestinal barrier by increasing the expression of Muc3, Cldn4, and Ocln. The higher production of short chain fatty acids in the cecum and increased Bifidobacterium counts suggest a potential positive impact on the gastrointestinal tract. These findings indicate that maternal synbiotic supplementation during gestation and lactation improves their immunological status and improved milk composition.

Effects of varying wheat levels on growth performance, intestinal barrier, and cecal microbiota of broilers.

The study aimed to investigate the potential effects of varying wheat levels in broiler diets on growth performance, intestinal barrier, and cecal microbiota. Day-old male broilers were fed the same diet until 10 d of age. Then they were randomly assigned to 1) the low-level wheat group, where inclusion of 15.0% and 25.0% wheat in the grower and finisher diet, respectively, 2) the medium-level wheat group with 30.0% and 40.0% of wheat in the grower and finisher periods; and 3) the high-level wheat dietary group, in which the grower and finisher diets contained 55.77% and 62.38% of wheat, respectively. Dietary treatments unaffected the body weight at 39 d, whereas incorporating high wheat in diets significantly increased the feed intake and reduced the feed conversion ratio from 10 to 39 d (p < 0.05). Except for increased phosphorus digestibility in the high wheat group, dietary treatments had no significant effect on the apparent digestibility of dry matter, crude protein, and ether extract. Meanwhile, the broilers that consumed the medium and high content of wheat presented a higher villus height and the ratio of villus height to crypt depth than those fed the low-level wheat birds. Feeding the medium-level wheat enhanced ileal integrity and depressed the expression of proinflammatory cytokines in the ileum. The addition of high levels of wheat reduced the Chao1 index and the abundance of Lactobacillaceae, Bacteroidaceae, and Ruminococcacea in cecal content, which probably decreased the metabolism of histidine, sulfur-containing amino acids, and the biosynthesis of lysine. These results support the medium-level wheat diet improved intestinal barrier function and had no deleterious effects on the growth performance of broiler; dietary inclusion of high wheat reduced the feed conversion rate, which might be associated with the disturbed gut microbiota and decreased metabolism of amino acids.

A type 4 resistant potato starch alters the cecal microbiome and gene expression in mice fed a western diet based on NHANES data.

Four major types of resistant starch (RS1-4) are present in foods, all of which can alter the microbiome and are fermented in the cecum and colon to produce short-chain fatty acids (SCFAs). Type 4 RSs are chemically modified starches, not normally found in foods, but have become a popular food additive as their addition increases fiber content. Multiple studies, in humans and rodents, have explored how different RS4 affect post-prandial glucose metabolism, but fewer studies have examined the effects of RS4 consumption on the microbiome. In addition, many RS studies conducted in rodents use high-fat diets that do not approximate what is typically consumed by humans. To address this, mice were fed a Total Western Diet (TWD), based on National Health and Nutrition Examination Survey (NHANES) data that mimics the macro and micronutrient composition of a typical American diet, for six weeks, and then supplemented with 0, 2, 5, or 10% of the RS4, Versafibe 1490™ (VF), a phosphorylated and cross-linked potato starch, for an additional three weeks. The cecal contents were analyzed for SCFA content and microbiota composition. Butyrate production was increased while branched chain SCFA production decreased. The alpha-diversity of the microbiome decreased in mice fed the TWD with 10% VF 1490 added while the beta-diversity plot showed that the 5% and 10% VF groups were distinct from mice fed the TWD. Similarly, the largest changes in relative abundance of various genera were greatest in mice fed the 10% VF diet. To examine the effect of VF consumption on tissue gene expression, cecal and distal colon tissue mRNA abundance were analyzed by RNASeq. Gene expression changes were more prevalent in the cecum than the colon and in mice fed the 10% VF diet, but the number of changes was substantially lower than we previously observed in mice fed the TWD supplemented with native potato starch (RPS). These results provide additional evidence that the structure of the RS is a major factor determining its effects on the microbiome and gene expression in the cecum and colon.

Effects of exposure to the neonicotinoid pesticide clothianidin on mouse intestinal microbiota under unpredictable environmental stress

Recent research has demonstrated the toxicity of neonicotinoid pesticides (NNs) in mammals through their interaction with nicotinic acetylcholine receptors (nAChRs). These effects are reported to extend to the intestinal microbiota as well. In addition, environmental stress affects the expression of nAChRs, which may alter sensitivity to NNs. In this study, we analyzed the intestinal microbiota of mice exposed to clothianidin (CLO), a type of NN, under environmental stress, and aimed to clarify the effects of such combined exposure on the intestinal microbiota. C57BL/6 N male mice (9 weeks old) were subchronically administered a no-observed-adverse-effect-level (NOAEL) CLO-mixed rehydration gel for 29 days and simultaneously subjected to chronic unpredictable mild stress (CUMS). After the administration period, cecum contents were collected and analyzed by 16S rRNA sequencing for intestinal microbiota. CLO exposure alone resulted in alterations in the relative abundance of Alistipes and ASF356, which produce short-chain fatty acids. The addition of CUMS amplified these changes. On the other hand, CLO alone did not affect the relative abundance of Lactobacillus, but the abundance decreased when CUMS was added. This study revealed that the combined exposure to CLO and stress not only amplifies their individual effects on intestinal microbiota but also demonstrates combined and multifaceted toxicities.

Immunoregulation of bovine lactoferrin together with osteopontin promotes immune system development and maturation.

The immune system of infants is partly weak and immature, and supplementation of infant formula can be of vital importance to boost the development of the immune system. Lactoferrin (LF) and osteopontin (OPN) are essential proteins in human milk with immunoregulation function. An increasing number of studies indicate that proteins have interactions with each other in milk, and our previous study found that a ratio of LF : OPN at 1 : 5 (w/w, denoted as LOP) had a synergistic effect on intestinal barrier protection. It remains unknown whether LOP can also exert a stronger effect on immunoregulation. Hence, we used an in vitro model of LPS-induced macrophage inflammation and in vivo models of LPS-induced intestinal inflammation and early life development. We showed that LOP increased the secretion of the granulocyte-macrophage colony-stimulating factor (132%), stem cell factor (167%) and interleukin-3 (176%) in bone marrow cells, as well as thymosin (155%) and interleukin-10 (161%) in the thymus, more than LF or OPN alone during development, and inhibited changes in immune cells and cytokines during the LPS challenge. In addition, analysis of the components of digested proteins in vitro revealed that differentially expressed peptides may provide immunoregulation. Lastly, LOP increased the abundance of Rikenellaceae, Muribaculum, Faecalibaculum, and Elisenbergiella in the cecum content. These results imply that LOP is a potential immunomodifier for infants and offers a new theoretical basis for infant formula innovation.

Danggui Buxue decoction regulates the immune function and intestinal microbiota of cyclophosphamide induced immunosuppressed mice.

Danggui Buxue decoction (DBD) is a traditional Chinese herbal formula. According to the theory of traditional Chinese medicine, the combination of Astragali Radix (AR) and Angelica sinensis (AS) is a classic prescription of tonifying qi and enriching blood. DBD has the functions of hematopoietic, immune enhancement and inflammation inhibition, usually used to treat qi and blood deficiency symptoms. Cyclophosphamide (CY) can inhibit humoral and cellular immunity, leading to the overall immune disorder of the body, resulting in immunosuppressive (IS). Pre-laboratory studies confirmed the immunomodulatory effects of DBD, but its mechanisms have not been thoroughly studied. In this study, the main purpose was to determine the effects of DBD on the immune function and intestinal mucosal barrier function of IS mice induced by CY, and initially explored the immunomodulatory mechanism of DBD. 100g of AR and 20g of AS were accurately weighed and 0.5g/mL of the DBD was obtained by boiling, filtration and rotary evaporation. Then, mice in the DBD group were administered 5g/kg of DBD by gavage, positive group were administered 40mg/kg of levamisole hydrochloride, whereas those in the control and model groups were given the corresponding volume of normal saline by gavage for 1week. At the end of the experiment, blood, spleen, thymus, ileum and cecum contents of all the experimental mice were collected aseptically. IS mouse model induced by intraperitoneal injection of 80mg/kg CY for three consecutive days. Pathomorphology was used to observe the physical barrier of the intestine, flow cytometry to detect splenic lymphocytes, immunohistochemistry to determine the content of intestinal barrier-associated proteins, ELISA to measure the secretion of ileal SIgA, qRT-PCR to detect the mRNA expression of immune-related genes in the intestine, and high-throughput sequencing and analysis of cecum contents. DBD alleviated spleen tissue damage and restored impaired immune functions, such as increased thymus index and CD4+/CD8+ subsets of spleen lymphocytes. In addition, DBD could increase ileum villi length and the ratio of villi length to crypt depth (V/C), and decrease crypt depth. Moreover, DBD administration up-regulated the expression of ZO-1, Occludin, Claudin-1, MUC-2 mRNA in ileum. And the secretions of sIgA and ZO-1 in ileum were also significantly improved. Furthermore, the administration of DBD can increase the diversity of gut microbiota, improve the composition of intestinal flora and increase the relative abundance of beneficial genus, such as Bacteroides. DBD alleviated CY-induced immune damage by decreasing the ratio of spleen index to CD4+/CD8+ of T lymphocyte subsets. And the intestinal barrier function of mice was by improves improving the intestinal morphology of the ileum and up-regulating the expression levels of ZO-1, MUC-2 and SIgA. DBD regulates CY-induced gut microbiota dysregulation in mice by increasing species diversity and richness, regulating the phylum, class and order levels of Bacteroidetes.

Matcha alleviates obesity by modulating gut microbiota and its metabolites

Matcha shows promise for diabetes, obesity, and gut microbiota disorders. Studies suggest a significant link between gut microbiota, metabolites, and obesity. Thus, matcha may have a positive impact on obesity by modulating gut microbiota and metabolites. This study used 16S rDNA sequencing and untargeted metabolomics to examine the cecal contents in mice. By correlation analysis, we explored the potential mechanisms responsible for the positive effects of matcha on obesity. The results indicated that matcha had a mitigating effect on the detrimental impacts of a high-fat diet (HFD) on multiple physiological indicators in mice, including body weight, adipose tissue weight, serum total cholesterol (TC), and low-density lipoprotein (LDL) levels, as well as glucose tolerance. Moreover, it was observed that matcha had an impact on the structural composition of gut microbiota and gut metabolites. Specifically, matcha was able to reverse the alterations in the abundance of certain obesity-improving bacteria, such as Alloprevotella, Ileibacterium, and Rikenella, as well as the abundance of obesity-promoting bacteria Romboutsia, induced by a HFD. Furthermore, matcha can influence the levels of metabolites, including formononetin, glutamic acid, pyroglutamic acid, and taurochenodeoxycholate, within the gastrointestinal tract. Additionally, matcha enhances caffeine metabolism and the HIF-1 signaling pathway in the KEGG pathway. The results of the correlation analysis suggest that formononetin, theobromine, 1,3,7-trimethyluric acid, and Vitamin C displayed negative correlation with both the obesity phenotype and microbiota known to exacerbate obesity, while demonstrating positive correlations with microbiota that alleviated obesity. However, glutamic acid, pyroglutamic acid, and taurochenodeoxycholate had the opposite effect. In conclusion, the impact of matcha on gut metabolites may be attributed to its modulation of the abundance of Alloprevotella, Ileibacterium, Rikenella, and Romboutsia within the gastrointestinal tract, thereby potentially contributing to the amelioration of obesity.

Panax notoginseng stems and leaves affect microbial community and function in cecum of duzang pigs.

Panax notoginseng is a Chinese medicine with a long history in which stems and leaves are the wastes of processing Panax notoginseng and have not been effectively utilized. The effects of diets containing Panax notoginseng stems and leaves on the cecal short-chain fatty acid (SCFA) concentration and microbiome of independent pigs were studied. Diets containing Panax notoginseng stems and leaves did not affect the concentration of SCFA in the cecal contents of Duzang pigs but affected the microbial composition and diversity. Firmicutes, Proteobacteria, and Bacteroidetes dominate in the cecal of Duzang pigs. Feeding Duzang pigs with a 10% Panax notoginseng stems and leaves diet increases the abundance of Lactobacillus, Christensenellaceae R-7 group, and Akkermansia in the cecal. We found 14 genera positively associated with acetate, and they were Lactobacillus, Ruminococcaceae UCG 005, Ruminiclostridium 6; Escherichia Shigella and Family XIII AD3011 group showed negative correlations. Solobacterium, Desulfovibrio, and Erysipelatoclostridium were positively associated with propionate. Campylobacter, Clostridium sensu stricto 11, and Angelakisella were positively associated with butyrate. In conclusion, Panax notoginseng stems and leaves could affect the cecal microbial community and functional composition of Duzang pigs. Panax notoginseng stems and leaves reduce the enrichment of lipopolysaccharide biosynthetic pathway of the cecal microbiome, which may have a positive effect on intestinal health. The higher abundance of GH25 family in Duzang pig's cecal microbiome of fed Panax notoginseng stems and leaves diet. This increase may be the reason for the microbial diversity decrease.

Streptococcus salivarius subsp. thermophilus CCFM1312 enhanced mice resilience to activity-based anorexia.

Probiotic intervention, already showing promise in the treatment of various psychiatric disorders like depression, emerges as a potential therapy for anorexia nervosa (AN) with minimal side effects. In this study, we established an activity-based anorexia (ABA) model to probe the pathogenesis of AN and assess the impact of probiotics on ABA mice. ABA resulted in a compensatory increase in duodenal ghrelin levels, impairing the regulation of feeding and the brain reward system. Intervention with Streptococcus salivarius subsp. thermophilus CCFM1312 ameliorated these ABA-induced effects, and the activation of neurons in the nucleus tractus solitarius (NTS) was observed following probiotic administration, revealing the advantageous role of probiotics in AN through the vagus nerve. Furthermore, our metabolomics analysis of cecal contents unveiled that S. salivarius subsp. thermophilus CCFM1312 modulated gut microbiota metabolism and thereby regulated intestinal ghrelin levels.

High methionine intake alters gut microbiota and lipid profile and leads to liver steatosis in mice.

Methionine is an important sulfur-containing amino acid. Health effects of both methionine restriction (MR) and methionine supplementation (MS) have been studied. This study aimed to investigate the impact of a high-methionine diet (HMD) (1.64% methionine) on both the gut and liver functions in mice through multi-omic analyses. Hepatic steatosis and compromised gut barrier function were observed in mice fed the HMD. RNA-sequencing (RNA-seq) analysis of liver gene expression patterns revealed the upregulation of lipid synthesis and degradation pathways, cholesterol metabolism and inflammation-related nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathway. Metagenomic sequencing of cecal content demonstrated a shift in gut microbial composition with an increased abundance of opportunistic pathogens and gut microbial functions with up-regulated lipopolysaccharide (LPS) biosynthesis in mice fed HMD. Metabolomic study of cecal content showed an altered gut lipid profile and the level of bioactive lipids, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), palmitoylethanolamide (PEA), linoleoyl ethanolamide (LEA) and arachidonoyl ethanolamide (AEA), that carry anti-inflammatory effects significantly reduced in the gut of mice fed the HMD. Correlation analysis demonstrated that gut microbiota was highly associated with liver and gut functions and gut bioactive lipid content. In conclusion, this study suggested that the HMD exerted negative impacts on both the gut and liver, and an adequate amount of methionine intake should be carefully determined to ensure normal physiological function without causing adverse effects.

Lactobacillus-derived indole derivatives ameliorate intestinal barrier damage in rat pups with complementary food administration.

The consumption of complementary foods can bring about diarrhea and intestinal barrier dysfunction in infants. In this study, three different Lactobacillus strains combined with L-tryptophan (Trp) were administered to rat pups with complementary foods. Complementary food feeding caused inflammatory cell infiltration, crypt structure irregularity and goblet cell reduction in the colon tissues of the rat pups. However, the oral administration of Trp combined with Lactiplantibacillus plantarum DPUL-S164 or Limosilactobacillus reuteri DPUL-M94 significantly restored the pathological changes in the colon tissues and inhibited the expression of pro-inflammatory cytokines in the colon and ileum of the rat pups. M94 or S164 combined with Trp intervention could promote the expression of cell differentiation genes and tight junction proteins, and restore the intestinal barrier damage caused by complementary foods in rat pups by activating the aryl hydrocarbon receptors (AhR) and nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. In addition, the indole-3-lactic acid (ILA), indole-3-propionic acid (IPA), or indole-3-carbaldehyde (I3C) level in the cecal contents of the rat pups increased after intervention of Trp combined with S164 or M94, which may account for the amelioration of intestinal barrier damage in rat pups administered with complementary foods. Furthermore, S164 or M94 combined with Trp intervention up-regulated the relative abundance of f_Lactobacillaceae, f_Akkermansiaceae, g_Lactobacillus, and g_Akkermansia in the intestinal tract of the rat pups. In conclusion, S164 or M94 combined with Trp intervention can ameliorate complementary food-induced intestinal barrier damage and gut flora disorder in rat pups by producing ILA, IPA, or I3C, which are AhR ligands.

Optimizing the Glass Bead Sterilization Protocol Focusing on Removal of Organic and Bacterial Intraoperative Contamination.

Validated glass bead sterilization protocols to effectively sterilize rodent surgical instruments after bacterial exposure (for example, cecal contamination) are lacking. To refine current approaches, we added either a multienzyme detergent, neutral pH detergent, or chlorhexidine scrub step before glass bead sterilization of forceps or needle drivers exposed to cecal contents. We exposed sets of forceps and needle drivers to cecal contents, which were then air dried for 3 min. Immediately after, the instruments were wiped several times with a clean, dry paper towel. The contaminated tips were soaked in either a multienzyme or neutral pH detergent (t = 5 min), chlorhexidine scrub (t = 2 min), or no pretreatment solution. To further increase debris removal, instruments (from all groups) were brushed using a clean toothbrush. The nonpretreatment instruments were briefly soaked in saline before brushing. After being rinsed with sterile water, all instruments were exposed to a glass bead sterilizer for 60 s at 500 °F (260 °C). Sets were then swabbed for bacterial culturing. Swabs were plated onto either sheep blood agar (n = 23) or chocolate agar (n = 20) for aerobic culturing or Brucella agar (n = 20) for anaerobic culturing. A subset of instruments was sampled to determine organic material presence after treatment using an ATP luminometer (n = 21). Multiple agar types and bioluminescence were used to more deeply evaluate tool sterility and to differentiate the relative effectiveness of each protocol. From the saline group, only one pair of forceps yielded growth on Brucella agar, and 2 pairs yielded growth on chocolate agar. No other bacterial growth was observed. The use of a pretreatment agent also lowered overall organic contamination levels in needle drivers compared with using only saline. These results indicate that brushing instruments to mechanically remove debris from instruments is paramount to ensure sterility. However, a best practice would be to also use one of the pretreatment options used in this study.

Integrating microbial 16S rRNA sequencing and non-targeted metabolomics to reveal sexual dimorphism of the chicken cecal microbiome and serum metabolome.

The gut microbiome plays a key role in the formation of livestock and poultry traits via serum metabolites, and empirical evidence has indicated these traits are sex-linked. We examined 106 chickens (54 male chickens and 52 female chickens) and analyzed cecal content samples and serum samples by 16S rRNA gene sequencing and non-targeted metabolomics, respectively. The cecal microbiome of female chickens was more stable and more complex than that of the male chickens. Lactobacillus and Family XIII UCG-001 were enriched in male chickens, while Eubacterium_nodatum_group, Blautia, unclassified_Anaerovoraceae, Romboutsia, Lachnoclostridium, and norank_Muribaculaceae were enriched in female chickens. Thirty-seven differential metabolites were identified in positive mode and 13 in negative mode, showing sex differences. Sphingomyelin metabolites possessed the strongest association with cecal microbes, while 11β-hydroxytestosterone showed a negative correlation with Blautia. These results support the role of sexual dimorphism of the cecal microbiome and metabolome and implicate specific gender factors associated with production performance in chickens.