Changes in the Mucosa-Associated Microbiome and Transcriptome across Gut Segments Are Associated with Obesity in a Metabolic Syndrome Porcine Model

The influence of host genotype and gut microbial interactions on feed efficiency traits in pigs

Feed efficiency and growth performance are economically important traits in pigs. Precious studies have been revealed that both genetics and gut microbes could influence host phenotypes, however, the mechanisms by which they affect pig growth and feed efficiency remain poorly understood. In this study, 361 crossbred Duroc × (Landrace × Yorkshire) commercial pigs were genotyped using GeneSeek Porcine SNP50K BeadChip, and the microbiotas from fecal samples were acquired using microbial 16S rRNA gene sequencing technology to investigate the impact of host genetics and gut microorganisms on growth and feed efficiency. The results showed that the heritability and enterobacterial force ranged from 0.27 to 0.46 and 0 to 0.03, respectively. Genome-wide association studies (GWAS) identified seven significant SNPs to be associated with growth and feed efficiency, and several genes, including AIF1L, ASS1, and QRFP were highlighted as candidates for the analyzed traits. Additionally, microbiome-genome-wide association studies GWAS revealed potential links between CCAR2, EGR3, GSTM3, and GPR61 genes and the abundance of microorganisms, such as Trueperella, Victivallis, and Erysipelatoclostridium. In addition, six microbial genera linked to growth and feed efficiency were identified as follows Lachnospiraceae_UCG-005, Prevotellaceae_UCG-003, Prevotellaceae_NK3B31_group, Prevotella_1, Prevotella_9, and Veillonella. Our findings provide novel insights into the factors influencing host phenotypic complexity and identify potential microbial targets for enhancing pig feed efficiency through selective breeding. This could aid in the development of strategies to manipulate the gut microbiota to optimize growth rates and feed efficiency in pig breeding.

Deficiency of SLC26A3 promotes jejunal barrier damage in metabolic disease-susceptible transgenic pigs

Intestinal disorders are common in metabolic syndrome. However, their pathogenesis is still not fully understood. Pig and human intestines are highly similar in terms of associated metabolic processes. Here, we successfully constructed a metabolic disease-susceptible transgenic (TG) Bama pig model by knocking in three humanized disease risk genes with the CRISPR/Cas9 technique to assess its potential as a model for human intestinal diseases and explore the possible pathological mechanisms involved. We found that jejunal barrier integrity was disrupted and that the infiltration of inflammatory cells increased in TG pigs after high-fat and high-sucrose diet (HFHSD) treatment. We revealed significant differences in the transcriptome, associated microbiome profiles and microbial metabolite short-chain fatty acid (SCFA) content of the jejunum of TG pigs. Notably, we found that SLC26A3 was significantly downregulated in TG pigs. Knockdown or overexpression of the SLC26A3 gene in IPEC-J2 cells significantly affected the expression of MUC2, MUC13 and occludin. Furthermore, in vitro experiments further verified that CDX2 directly regulated the expression of SLC26A3. Mechanistically, CDX2 mediated intestinal barrier function by enhancing the expression of SLC26A3 by binding to its promoter region between -1120 and - 1070 bp. TG pigs represent a promising model that provides new insights into preclinical research on human intestinal metabolic diseases associated with metabolic disorders and revealed that SLC26A3 may be a potential therapeutic target for intestinal metabolic diseases.

Dietary crude protein and protein solubility manipulation enhances intestinal nitrogen absorption and mitigates reactive nitrogen emissions through gut microbiota and metabolome reprogramming in sheep

Dietary nutrient manipulation (e.g. protein fractions) could lower the environmental footprints of ruminants, especially reactive nitrogen (N). This study investigated the impacts of dietary soluble protein (SP) levels with decreased crude protein (CP) on intestinal N absorption, hindgut N metabolism, fecal microbiota and metabolites, and their linkage with N metabolism phenotype. Thirty-two male Hu sheep, with an age of six months and an initial BW of 40.37 ± 1.18 kg, were randomly assigned to four dietary groups. The control diet (CON), aligning with NRC standards, maintained a CP content of 16.7% on a dry matter basis. Conversely, the experimental diets (LPA, LPB, and LPC) featured a 10% reduction in CP compared with CON, accompanied by SP adjustments to 21.2%, 25.9%, and 29.4% of CP, respectively. Our results showed that low-protein diets led to significant reductions in the concentrations of plasma creatinine, ammonia, urea N, and fecal total short-chain fatty acids (SCFA) (P < 0.05). Notably, LPB and LPC exhibited increased total SCFA and propionate concentrations compared with LPA (P < 0.05). The enrichment of the Prevotella genus in fecal microbiota associated with energy metabolism and amino acid (AA) biosynthesis pathways was evident with SP levels in low-protein diets of approximately 25% to 30%. Moreover, LPB and LPC diets demonstrated a decrease in fecalNH 4 + -N andNO 2 - -N contents as well as urease activity, compared with CON (P < 0.05). Concomitantly, reductions in fecal glutamic acid dehydrogenase gene (gdh), nitrite reductase gene (nirS), and nitric oxide reductase gene (norB) abundances were observed (P < 0.05), pointing towards a potential reduction in reactive N production at the source. Of significance, the up-regulation of mRNA abundance of AA and peptide transporters in the small intestine (duodenum, jejunum, and ileum) and the elevated concentration of plasma AA (e.g. arginine, methionine, aspartate, glutamate, etc.) underscored the enhancement of N absorption and N efficiency. In summary, a 10% reduction in CP, coupled with an SP level of approximately 25% to 30%, demonstrated the potential to curtail reactive N emissions through fecal Prevotella enrichment and improve intestinal energy and N utilization efficiency.

Mapping the geographical distribution of the mucosa-associated gut microbiome in GI-symptomatic children with autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by cognitive, behavioral, and communication impairments. In the past few years, it has been proposed that alterations in the gut microbiota may contribute to an aberrant communication between the gut and brain in children with ASD. Consistent with this notion, several studies have demonstrated that children with ASD have an altered fecal microbiota compared with typically developing (TD) children. However, it is unclear where along the length of the gastrointestinal (GI) tract these alterations in microbial communities occur. In addition, the variation between specific mucosa-associated communities remains unknown. To address this gap in knowledge of the microbiome associated with ASD, biopsies from the antrum, duodenum, ileum, right colon, and rectum of children with ASD and age- and sex-matched TD children were examined by 16S rRNA sequencing. We observed an overall elevated abundance of Bacillota and Bacteroidota and a decreased abundance of Pseudomonadota in all GI tract regions of both male and female children with ASD compared with TD children. Further analysis at the genera level revealed unique differences in the microbiome in the different regions of the GI tract in children with ASD compared with TD children. We also observed sex-specific differences in the gut microbiota composition in children with ASD. These data indicate that the microbiota of children with ASD is altered in multiple regions of the GI tract and that different anatomic locations have unique alterations in mucosa-associated bacterial genera.NEW & NOTEWORTHY Analysis in stool samples has shown gut microbiota alterations in children with autism spectrum disorder (ASD) compared with typically developing (TD) children. However, it is unclear which segment(s) of the gut exhibit alterations in microbiome composition. In this study, we examined microbiota composition along the gastrointestinal (GI) tract in the stomach, duodenum, ileum, right colon, and rectum. We found site-specific and sex-specific differences in the gut microbiota of children with ASD, compared with controls.

Distinct Gut Microbiota and Arachidonic Acid Metabolism in Obesity-Prone and Obesity-Resistant Mice with a High-Fat Diet

An imbalance of energy intake and expenditure is commonly considered as the fundamental cause of obesity. However, individual variations in susceptibility to obesity do indeed exist in both humans and animals, even among those with the same living environments and dietary intakes. To further explore the potential influencing factors of these individual variations, male C57BL/6J mice were used for the development of obesity-prone and obesity-resistant mice models and were fed high-fat diets for 16 weeks. Compared to the obesity-prone mice, the obesity-resistant group showed a lower body weight, liver weight, adipose accumulation and pro-inflammatory cytokine levels. 16S rRNA sequencing, which was conducted for fecal microbiota analysis, found that the fecal microbiome's structural composition and biodiversity had changed in the two groups. The genera Allobaculumbiota, SMB53, Desulfovibrio and Clostridium increased in the obesity-prone mice, and the genera Streptococcus, Odoribacter and Leuconostoc were enriched in the obesity-resistant mice. Using widely targeted metabolomics analysis, 166 differential metabolites were found, especially those products involved in arachidonic acid (AA) metabolism, which were significantly reduced in the obesity-resistant mice. Moreover, KEGG pathway analysis exhibited that AA metabolism was the most enriched pathway. Significantly altered bacteria and obesity-related parameters, as well as AA metabolites, exhibited strong correlations. Overall, the phenotypes of the obesity-prone and obesity-resistant mice were linked to gut microbiota and AA metabolism, providing new insight for developing an in-depth understanding of the driving force of obesity resistance and a scientific reference for the targeted prevention and treatment of obesity.

Exercise Affects Mucosa-Associated Microbiota and Colonic Tumor Formation Induced by Azoxymethane in High-Fat-Diet-Induced Obese Mice

The only reliable factor that reduces the risk of colorectal carcinogenesis is physical activity. However, the underlying mechanisms remain unclear. In this study, we examined the effects of physical activity against gut microbiota, including mucosa-associated microbiota (MAM) on azoxymethane-induced colorectal tumors in obese mice. We divided the subjects into four groups: normal diet (ND), high-fat diet (HFD), ND + exercise (Ex), and HFD + Ex groups. The Ex group performed treadmill exercise for 20 weeks. Thereafter, fecal and colonic mucus samples were extracted for microbiota analysis. DNA was collected from feces and colonic mucosa, and V3-V4 amplicon sequencing analysis of the 16SrRNA gene was performed using MiSeq. The HFD group had significantly more colonic polyps than the ND group (ND 6.5 ± 1.3, HFD 11.4 ± 1.5, p < 0.001), and the addition of Ex suppressed the number of colonic polyps in ND and HFD groups (ND 6.5 ± 1.3, ND + Ex 2.8 ± 2.5, p < 0.05). The HFD group showed significantly lower concentrations of succinic, acetic, butyric, and propionic acids (mg/g) in feces, compared with the ND group (succinic acid HFD 0.59, ND 0.17; acetic acid HFD 0.63, ND 2.41; propionic acid HFD 0.10, ND 0.47; and N-butyric acid HFD 0.31, ND 0.93). In the case of ND, succinic acid and butyric acid tended to decrease with Ex (succinic acid ND 0.17, ND + Ex 0.12; N-butyric acid ND 0.93, ND + Ex 0.74 0.74). Succinic acid, acetic acid, butyric acid, and propionic acid levels in feces were significantly lower in the HFD group than in the ND group; in both feces and mucus samples, Butyricicoccus and Lactobacillus levels were significantly lower in the HFD group. Akkermansia was significantly increased in ND + Ex and HFD + Ex groups. Diet and exercise affected the number of colorectal tumors. Furthermore, diet and exercise alter intestinal MAM, which may be involved in colorectal tumor development.

mbDecoda: a debiased approach to compositional data analysis for microbiome surveys

Potentially pathogenic or probiotic microbes can be identified by comparing their abundance levels between healthy and diseased populations, or more broadly, by linking microbiome composition with clinical phenotypes or environmental factors. However, in microbiome studies, feature tables provide relative rather than absolute abundance of each feature in each sample, as the microbial loads of the samples and the ratios of sequencing depth to microbial load are both unknown and subject to considerable variation. Moreover, microbiome abundance data are count-valued, often over-dispersed and contain a substantial proportion of zeros. To carry out differential abundance analysis while addressing these challenges, we introduce mbDecoda, a model-based approach for debiased analysis of sparse compositions of microbiomes. mbDecoda employs a zero-inflated negative binomial model, linking mean abundance to the variable of interest through a log link function, and it accommodates the adjustment for confounding factors. To efficiently obtain maximum likelihood estimates of model parameters, an Expectation Maximization algorithm is developed. A minimum coverage interval approach is then proposed to rectify compositional bias, enabling accurate and reliable absolute abundance analysis. Through extensive simulation studies and analysis of real-world microbiome datasets, we demonstrate that mbDecoda compares favorably with state-of-the-art methods in terms of effectiveness, robustness and reproducibility.

Inhibitory Effects of Jiuzao Polysaccharides on Alcoholic Fatty Liver Formation in Zebrafish Larvae and Their Regulatory Impact on Intestinal Microbiota

The liver is critical in alcohol metabolism, and excessive consumption heightens the risk of hepatic damage, potentially escalating to hepatitis and cirrhosis. Jiuzao, a by-product of Baijiu production, contains a rich concentration of naturally active polysaccharides known for their antioxidative properties. This study investigated the influence of Laowuzeng Jiuzao polysaccharide (LJP) on the development of ethanol-induced alcoholic fatty liver. Zebrafish larvae served as the model organisms for examining the LJPs hepatic impact via liver phenotypic and biochemical assays. Additionally, this study evaluated the LJPs effects on gene expression associated with alcoholic fatty liver and the composition of the intestinal microbiota through transcriptomic and 16 S rRNA gene sequencing analyses, respectively. Our findings revealed that LJP markedly mitigated morphological liver damage and reduced oxidative stress and lipid peroxidation in larvae. Transcriptome data indicated that LJP ameliorated hepatic fat accumulation and liver injury by enhancing gene expression involved in alcohol and lipid metabolism. Furthermore, LJP modulated the development of alcoholic fatty liver by altering the prevalence of intestinal Actinobacteriota and Firmicutes, specifically augmenting Acinetobacter while diminishing Chryseobacterium levels. Ultimately, LJP mitigated alcohol-induced hepatic injury by modulating gene expression related to ethanol metabolism, lipid metabolism, and inflammation and by orchestrating alterations in the intestinal microbiota.

Linking active rectal mucosa-attached microbiota to host immunity reveals its role in host-pathogenic STEC O157 interactions

The rectal-anal junction (RAJ) is the major colonization site of Shiga toxin-producing Escherichia coli (STEC) O157 in beef cattle, leading to transmission of this foodborne pathogen from farms to food chains. To date, there is limited understanding regarding whether the mucosa-attached microbiome has a profound impact on host-STEC interactions. In this study, the active RAJ mucosa-attached microbiota and its potential role in host immunity-STEC commensal interactions were investigated using RAJ mucosal biopsies collected from calves orally challenged with two STEC O157 strains with or without functional stx2a (stx2a+ or stx2a-). The results revealed that shifts of microbial diversity, topology, and assembly patterns were subjected to stx2a production post-challenge and Paeniclostridium and Gallibacterium were the keystone taxa for both microbial interactions and assembly. Additional mucosal transcriptome profiling showed stx2a-dependent host immune responses (i.e. B- and T-cell signaling and antigen processing and presentation) post-challenge. Further integrated analysis revealed that mucosa-attached beneficial microbes (i.e. Provotella, Faecalibacterium, and Dorea) interacted with host immune genes pre-challenge to maintain host homeostasis; however, opportunistic pathogenic microbes (i.e. Paeniclostridium) could interact with host immune genes after the STEC O157 colonization and interactions were stx2a-dependent. Furthermore, predicted bacterial functions involved in pathogen (O157 and Paeniclostridium) colonization and metabolism were related to host immunity. These findings suggest that during pathogen colonization, host-microbe interactions could shift from beneficial to opportunistic pathogenic bacteria driven and be dependent on the production of particular virulence factors, highlighting the potential regulatory role of mucosa-attached microbiota in affecting pathogen-commensal host interactions in calves with STEC O157 infection.

Salmonella enterica serovar Choleraesuis vector outperforms alum as an adjuvant, increasing a cross-protective immune response against Glaesserella parasuis

The adjuvant and/or vector significantly affect a vaccine's efficacy. Although traditional adjuvants such as alum have contributed to vaccine development, deficiencies in the induction of cellular and mucosal immunity have limited their further promotion. Salmonella vectors have unique advantages for establishing cellular and mucosal immunity due to mucosal pathways of invasion and intracellular parasitism. In addition, Salmonella vectors can activate multiple innate immune pathways, thereby promoting adaptive immune responses. In this work, the attenuated Salmonella enterica serovar Choleraesuis (S. Choleraesuis) vector rSC0016 was used to deliver the conserved protective antigen HPS_06257 of Glaesserella parasuis (G. parasuis), generating a novel recombinant strain rSC0016(pS-HPS_06257). The rSC0016(pS-HPS_06257) can express and deliver the HPS_06257 protein to the lymphatic system of the host. In comparison to HPS_06257 adjuvanted with alum, rSC0016(pS-HPS_06257) significantly increased TLR4 and TLR5 activation in mice as well as the levels of proinflammatory cytokines. In addition, rSC0016 promoted a greater degree of maturation in bone marrow-derived dendritic cells (BMDCs) than alum. The specific humoral, mucosal, and cellular immune responses against HPS_06257 in mice immunized with rSC0016(pS-HPS_06257) were significantly higher than those of HPS_06257 adjuvanted with alum. HPS_06257 delivered by the S. Choleraesuis vector induces a Th1-biased Th1/Th2 mixed immune response, while HPS adjuvanted with alum can only induce a Th2-biased immune response. HPS_06257 adjuvanted with alum only causes opsonophagocytic activity (OPA) responses against a homologous strain (G. parasuis serotype 5, GPS5), whereas rSC0016(pS-HPS_06257) could generate cross-OPA responses against a homologous strain and a heterologous strain (G. parasuis serotype 12, GPS12). Ultimately, HPS_06257 adjuvanted with alum protected mice against lethal doses of GPS5 challenge by 60 % but failed to protect mice against lethal doses of GPS12. In contrast, mice immunized with rSC0016(pS-HPS_06257) had 100 % or 80 % survival when challenged with lethal doses of GPS5 or GPS12, respectively. Altogether, the S. Choleraesuis vector rSC0016 could potentially generate an improved innate immune response and an improved adaptive immunological response compared to the traditional alum adjuvant, offering a novel concept for the development of a universal G. parasuis vaccine.

Alterations of ileal mucosa-associated microbiota in hypercholesterolemia patients

Many metabolic diseases have been demonstrated to be associated with changes in the microbiome. However, no studies have yet been conducted to examine the characteristics of the mucosal microbiota of patients with hypercholesterolemia. We aimed to examine mucosa-associated microbiota in subjects with hypercholesterolemia. We conducted a case-control study, in which ileal mucosal samples were collected from 13 hypercholesterolemia patients and 13 controls for 16S rRNA gene sequencing. There were differences in the composition of ileal mucosal microbiota based on beta diversity between the hypercholesterolemia and control groups (P < 0.05). Compared with the control group, the phylum Bacteroidetes and the genera Bacteroides, Butyricicoccus, Parasutterella, Candidatus_Soleaferrea, and norank_f__norank_o__Izemoplasmatales were less abundant in the hypercholesterolemia group (P < 0.05), while the genus Anaerovibrio was enriched in the hypercholesterolemia group (P < 0.05). The relative abundance of Bacteroides was negatively correlated with total cholesterol and low-density lipoprotein cholesterol (P < 0.01). The relative abundance of Coprococcus was negatively correlated with triglycerides and body mass index (all P < 0.05). PICRUSt functional prediction analysis showed that pathways related to Glycerophospholipid metabolism, ABC transporters, Phosphotransferase system, and Biofilm formation - Escherichia coli, and infectious diseases of pathogenic Escherichia coli were enriched in the hypercholesterolemia group. This work suggests a potential role of ileal mucosal microbiota in the development of hypercholesterolemia.

Transmission of Alzheimer's disease-associated microbiota dysbiosis and its impact on cognitive function: evidence from mice and patients

Spouses of Alzheimer's disease (AD) patients are at a higher risk of developing incidental dementia. However, the causes and underlying mechanism of this clinical observation remain largely unknown. One possible explanation is linked to microbiota dysbiosis, a condition that has been associated with AD. However, it remains unclear whether gut microbiota dysbiosis can be transmitted from AD individuals to non-AD individuals and contribute to the development of AD pathogenesis and cognitive impairment. We, therefore, set out to perform both animal studies and clinical investigation by co-housing wild-type mice and AD transgenic mice, analyzing microbiota via 16S rRNA gene sequencing, measuring short-chain fatty acid amounts, and employing behavioral test, mass spectrometry, site-mutations and other methods. The present study revealed that co-housing between wild-type mice and AD transgenic mice or administrating feces of AD transgenic mice to wild-type mice resulted in AD-associated gut microbiota dysbiosis, Tau phosphorylation, and cognitive impairment in the wild-type mice. Gavage with Lactobacillus and Bifidobacterium restored these changes in the wild-type mice. The oral and gut microbiota of AD patient partners resembled that of AD patients but differed from healthy controls, indicating the transmission of microbiota. The underlying mechanism of these findings includes that the butyric acid-mediated acetylation of GSK3β at lysine 15 regulated its phosphorylation at serine 9, consequently impacting Tau phosphorylation. Pending confirmative studies, these results provide insight into a potential link between the transmission of AD-associated microbiota dysbiosis and development of cognitive impairment, which underscore the need for further research in this area.

Key elements determining the intestinal region-specific environment of enteric neurons in type 1 diabetes

Diabetes, as a metabolic disorder, is accompanied with several gastrointestinal (GI) symptoms, like abdominal pain, gastroparesis, diarrhoea or constipation. Serious and complex enteric nervous system damage is confirmed in the background of these diabetic motility complaints. The anatomical length of the GI tract, as well as genetic, developmental, structural and functional differences between its segments contribute to the distinct, intestinal region-specific effects of hyperglycemia. These observations support and highlight the importance of a regional approach in diabetes-related enteric neuropathy. Intestinal large and microvessels are essential for the blood supply of enteric ganglia. Bidirectional morpho-functional linkage exists between enteric neurons and enteroglia, however, there is also a reciprocal communication between enteric neurons and immune cells on which intestinal microbial composition has crucial influence. From this point of view, it is more appropriate to say that enteric neurons partake in multidirectional communication and interact with these key players of the intestinal wall. These interplays may differ from segment to segment, thus, the microenvironment of enteric neurons could be considered strictly regional. The goal of this review is to summarize the main tissue components and molecular factors, such as enteric glia cells, interstitial cells of Cajal, gut vasculature, intestinal epithelium, gut microbiota, immune cells, enteroendocrine cells, pro-oxidants, antioxidant molecules and extracellular matrix, which create and determine a gut region-dependent neuronal environment in diabetes.

Transmission of Alzheimer's Disease-Associated Microbiota Dysbiosis and its Impact on Cognitive Function: Evidence from Mouse Models and Human Patients

Spouses of Alzheimer's disease (AD) patients are at higher risk of developing AD dementia, but the reasons and underlying mechanism are unknown. One potential factor is gut microbiota dysbiosis, which has been associated with AD. However, it remains unclear whether the gut microbiota dysbiosis can be transmitted to non-AD individuals and contribute to the development of AD pathogenesis and cognitive impairment. The present study found that co-housing wild-type mice with AD transgenic mice or giving them AD transgenic mice feces caused AD-associated gut microbiota dysbiosis, Tau phosphorylation, and cognitive impairment. Gavage with Lactobacillus and Bifidobacterium restored these changes. The oral and gut microbiota of AD patient partners resembled that of AD patients but differed from healthy controls, indicating the transmission of oral and gut microbiota and its impact on cognitive function. The underlying mechanism of these findings includes that the butyric acid-mediated acetylation of GSK3β at lysine 15 regulated its phosphorylation at serine 9, consequently impacting Tau phosphorylation. These results provide insight into a potential link between gut microbiota dysbiosis and AD and underscore the need for further research in this area.

Characterization of A-to-I Editing in Pigs under a Long-Term High-Energy Diet

Long-term high-energy intake has detrimental effects on pig health and elevates the risk of metabolic disease. RNA editing modifying RNA bases in a post-transcriptional process has been extensively studied for model animals. However, less evidence is available that RNA editing plays a role in the development of metabolic disorders. Here, we profiled the A-to-I editing in three tissues and six gut segments and characterized the functional aspect of editing sites in model pigs for metabolic disorders. We detected 64,367 non-redundant A-to-I editing sites across the pig genome, and 20.1% correlated with their located genes' expression. The largest number of A-to-I sites was found in the abdominal aorta with the highest editing levels. The significant difference in editing levels between high-energy induced and control pigs was detected in the abdominal aorta, testis, duodenum, ileum, colon, and cecum. We next focused on 6041 functional A-to-I sites that detected differences or specificity between treatments. We found functional A-to-I sites specifically involved in a tissue-specific manner. Two of them, located in gene SLA-DQB1 and near gene B4GALT5 were found to be shared by three tissues and six gut segments. Although we did not find them enriched in each of the gene features, in correlation analysis, we noticed that functional A-to-I sites were significantly enriched in gene 3'-UTRs. This result indicates, in general, A-to-I editing has the largest potential in the regulation of gene expression through changing the 3'-UTRs' sequence, which is functionally involved in pigs under a long-term high-energy diet. Our work provides valuable knowledge of A-to-I editing sites functionally involved in the development of the metabolic disorder.

Fermented Cerasus humilis fruits protect against high-fat diet induced hyperlipidemia which is associated with alteration of gut microbiota

BACKGROUND

Hyperlipidemia is regarded as a public health matter, and its effective prevention and treatment are urgently required. However, the treatment of hyperlipidemia is still relatively scarce.

RESULTS

Fermented Cerasus humilis fruit (FCHF) had higher total flavonoid, total phenolic, procyanidin, and organic and free amino acid content, and lower total sugar content, than non-fermented C. humilis fruit (NFCHF). Both FCHF and NFCHF treatment significantly prevent putting on weight. Furthermore, FCHF administration ameliorated hyperlipidemia and cholesterol over-accumulation. In addition, FCHF administration activated the antioxidase system and decreased the malondialdehyde content to relieve oxidative stress, and showed more efficaciously than NFCHF administration. FCHF treatments significantly reverse the fat deposition in high-fat diet rat liver. FCHF supplementation can relieve the dysbacteriosis induced by hyperlipidemia, and regulate the composition of rat gut microbiota by increasing the abundance of Prevotella and norank_f_Muribaculaceae.

CONCLUSION

Lactobacillus plantarum and Saccharomyces cerevisiae fermentation enhanced the antihyperlipidemic property of C. humilis fruits by promoting gut microbiota regulation. © 2022 Society of Chemical Industry.

Alterations in hepatic transcriptome and cecum microbiota underlying potential ways to prevent early fatty liver in laying hens

Fatty liver syndrome (FLS) is a kind of nutritional metabolic disease in laying hens. Revealing FLS pathogenesis during the early period is what really makes sense for the prevention or nutritional regulation strategies. In the study, 9 healthy or naturally occurring early FLS birds were screened based on visual inspection, liver index and morphologic analysis. Liver and fresh cecal content samples were collected. Then transcriptomic and 16S rRNA technologies are applied to investigate hepatic transcriptome and cecum microbiota composition. Unpaired Student t test and some omics methods were used for statistical analysis. Results showed higher liver weight and index were found in FLS group; morphologic analysis indicated that there existed more lipid droplets in the liver of birds with FLS. Based on DESeq2 analysis, there were 229 up- and 487 down-regulated genes in the FLS group, among which most genes related to de novo fatty acid synthesis were up-regulated such as acetyl-CoA carboxylase, fatty acid synthase, stearoyl-CoA desaturase, and ELOVL fatty acid elongase 6 (ELOVL6). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that pathways associated with lipid metabolism and liver damage were affected. 16S rRNA sequencing analysis of cecum microbiota showed that there was a significant difference between the Con and FLS groups. LEfSe analysis revealed that the relative abundance of Coprococcus, Odoribacter, Collinsella, Turicibacter, YRC22, Enterococcus, Shigella, and Bifidobacterium were down-regulated in the FLS group, whereas the abundance of Bacteroides, Mucispirillum, Butyricicoccus, Campylobacter, Akkermansia, and Clostridium were up-regulated. The KEGG enrichment from differential microbiota suggested that some metabolism-related functions were altered to some extent. Taken together, during the developmental of early fatty liver of laying hens, lipogenesis was enhanced, whereas abnormal metabolism occurs not only in lipid transportation but also in hydrolysis, which caused structural damage to the liver organ. Moreover, the dysbiosis of the cecum microbiota occurred. All of these serve as targets or provide theoretical references for the development of probiotics for fatty liver prevention in laying hens.

Association of gut microbiota and SCFAs with finishing weight of Diannan small ear pigs

Finishing weight is a key economic trait in the domestic pig industry. Evidence has linked the gut microbiota and SCFAs to health and production performance in pigs. Nevertheless, for Diannan small ear (DSE) pigs, a specific pig breed in China, the potential effect of gut microbiota and SCFAs on their finishing weight remains unclear. Herein, based on the data of the 16S ribosomal RNA gene and metagenomic sequencing analysis, we found that 13 OTUs could be potential biomarkers and 19 microbial species were associated with finishing weight. Among these, carbohydrate-decomposing bacteria of the families Streptococcaceae, Lactobacillaceae, and Prevotellaceae were positively related to finishing weight, whereas the microbial taxa associated with intestinal inflammation and damage exhibited opposite effects. In addition, interactions of these microbial species were found to be linked with finishing weight for the first time. Gut microbial functional annotation analysis indicated that CAZymes, such as glucosidase and glucanase could significantly affect finishing weight, given their roles in increasing nutrient absorption efficiency. Kyoto Encyclopedia of Genes and Genomes (KEGG) Orthologies (KOs) and KEGG pathways analysis indicated that glycolysis/gluconeogenesis, phosphotransferase system (PTS), secondary bile acid biosynthesis, ABC transporters, sulfur metabolism, and one carbon pool by folate could act as key factors in regulating finishing weight. Additionally, SCFA levels, especially acetate and butyrate, had pivotal impacts on finishing weight. Finishing weight-associated species Prevotella sp. RS2, Ruminococcus sp. AF31-14BH and Lactobacillus pontis showed positive associations with butyrate concentration, and Paraprevotella xylaniphila and Bacteroides sp. OF04-15BH were positively related to acetate level. Taken together, our study provides essential knowledge for manipulating gut microbiomes to improve finishing weight. The underlying mechanisms of how gut microbiome and SCFAs modulate pigs' finishing weight required further elucidation.