Insights into Butyrate Production in a Controlled Fermentation System via Gene Predictions

Heyndrickxia coagulans strain SANK70258 suppresses symptoms of upper respiratory tract infection via immune modulation: a randomized, double-blind, placebo-controlled, parallel-group, comparative study

Probiotic consumption strongly influences local intestinal immunity and systemic immune status. Heyndrickxia coagulans strain SANK70258 (HC) is a spore-forming lactic acid bacterium that has immunostimulatory properties on peripheral tissues. However, few reports have examined the detailed effectiveness of HC on human immune function and its mechanism of action. Therefore, we conducted a randomized, double-blind, placebo-controlled, parallel-group study to comprehensively evaluate the effects of HC on immunostimulatory capacity, upper respiratory tract infection (URTI) symptoms, and changes in intestinal organic-acid composition. Results of a questionnaire survey of URTI symptoms showed that runny nose, nasal congestion, sneezing, and sore throat scores as well as the cumulative number of days of these symptoms were significantly lower in the HC group than in the placebo group during the study period. Furthermore, the salivary secretory immunoglobulin A (sIgA) concentration was significantly higher, and the natural killer (NK) cell activity tended to be higher in the HC group than in the placebo group. In addition, we performed an exposure culture assay of inactivated influenza virus on peripheral blood mononuclear cells (PBMCs) isolated from the blood of participants in the HC and placebo groups. Gene-expression analysis in PBMCs after culture completion showed that IFNα and TLR7 expression levels were significantly higher in the HC group than in the placebo group. In addition, the expression levels of CD304 tended to be higher in the HC group than in the placebo group. On the other hand, the HC group showed a significantly higher increase in the intestinal butyrate concentration than the placebo group. HC intake also significantly suppressed levels of IL-6 and TNFα produced by PBMCs after exposure to inactivated influenza virus. Collectively, these results suggest that HC activated plasmacytoid dendritic cells expressing TLR7 and CD304 and strongly induced IFNα production, subsequently activating NK cells and increasing sIgA levels, and induced anti-inflammatory effects via increased intestinal butyrate levels. These changes may contribute to the acquisition of host resistance to viral infection and URTI prevention.

Butyrate acts as a positive allosteric modulator of the 5-HT transporter to decrease availability of 5-HT in the ileum

BACKGROUND AND PURPOSE

Radiation therapy-induced gastrointestinal distress is partly associated with the elimination of gut microbiota. The effectiveness of 5-HT receptor antagonists to treat radiation therapy-induced emesis implies a pathophysiological role of 5-HT. Peripheral 5-HT is derived from intestinal epithelium. We have investigated the role of gut microbiota in regulating intestinal 5-HT availability.

EXPERIMENTAL APPROACH

A radiation therapy murine model accompanied by faecal microbiota transplantation from donors fed different diets was investigated, and mouse ileal organoids were used for mechanistic studies. The clinical relevance was validated by a small-scale human study.

KEY RESULTS

Short-term high-fat diet (HFD) induced gut bacteria to produce butyrate. Irradiated mice receiving HFD-induced microbiome had the lowest ileal levels of 5-HT, compared with other recipients. Treatment with butyrate increased 5-HT uptake in mouse ileal organoids, assayed by the real-time tracking of a fluorescent substrate for monoamine transporters. Silencing the 5-HT transporter (SERT) in the organoids abolished butyrate-stimulated 5-HT uptake. The competitive tests using different types of selective 5-HT reuptake inhibitors suggested that butyrate acted as a positive allosteric modulator of SERT. In human gut microbiota, butyrate production was associated with the interconversion between acetate and butyrate. Faecal contents of both acetate and butyrate were negatively associated with serum 5-HT, but only butyrate was positively correlated with body mass index in humans.

CONCLUSION AND IMPLICATIONS

Short-term HFD may be beneficial for alleviating gastrointestinal reactions by increasing butyrate to suppress local 5-HT levels and providing energy to cancer patients given radiation therapy.

Effects of Dietary Callicarpa nudiflora Aqueous Extract Supplementation on Growth Performance, Growth Hormone, Antioxidant and Immune Function, and Intestinal Health of Broilers

C. nudiflora is notably rich in flavonoids and phenylethanoid glycosides, making it a significant natural source of antioxidants. We examined the effects of C. nudiflora aqueous extract (CNE) on growth performance, antioxidant function, immunity, intestinal barrier function, nutrient transporters, and microbiota of broilers. A total of 360 one-day-old broilers were randomly assigned to four treatment groups: a basal diet with 0 (control, CON), 300 mg/kg (CNEL), 500 mg/kg (CNEM), and 700 mg/kg (CNEH) CNE for 42 days. CNEL and CNEM groups quadratically increased body weight and average daily gain but decreased feed-to-gain ratios during the starter and whole phases. Regarding the immune response of broilers, CNE treatment linearly down-regulated jejunal myeloid differentiation factor 88 (MyD88) expression and interleukin-1β (IL-1β) and interferon-γ expression in the liver (d 21), while decreasing jejunal IL-1β expression and the concentration of serum tumor necrosis factor-α and interleukin-6 (d 42). The CNEM and CNEH groups had lower MyD88 and nuclear factor kappa B expression in the liver (d 21) compared to the CON group. Broilers in the CNEL and CNEM groups had higher spleen index and thymus index (d 21) and interleukin-10 expression from the liver and jejunal mucosa (d 42) than that in the CON group. For the antioxidant capacity of broilers, CNE treatment linearly decreased the content of malonaldehyde and increased the activity of total antioxidant capacity in serum (d 42). CNEM and CNEH groups linearly increased the activity of superoxide dismutase in serum and heme oxygenase-1 expression in the liver, while increasing the activity of glutathione peroxidase in serum, jejunal nuclear factor E2-related factor 2 expression, and NAD(P)H quinone oxidoreductase 1 expression in the liver (d 42). As for the growth hormone of broilers, CNEM group increased the level of serum insulin-like growth factor 1 and up-regulated jejunal glucagon-like peptide 2 (GLP-2) expression (d 21). Broilers in the CNEM and CNEH groups had higher jejunal GLP-2 expression and growth hormone (GH) expression in the liver and the level of serum GH (d 42) than that in the CON group. Additionally, the villus height and jejunal Occludin and Claudin-1 expression in the CNEM group increased. CNE-containing diets resulted in a linear increase in the expression of jejunal zonula occluden-1 (d 21), villus height to crypt depth ratio, jejunal Occludin, excitatory amino acid transporters-3, and peptide-transporter 1 (d 42). The regulation of Oscillospira, Ruminococcaceae_Ruminococcus, and Butyricicoccus genera indicated that CNEH altered the composition of the cecal microbiota. In general, supplementing broilers with C. nudiflora aqueous extract could boost hormones, immune and antioxidant function, and gut health, improving their growth performance. Hence, CNE was a promising poultry feed additive, with 500 mg/kg appearing to be the optimal dose.

Enhancing pig growth and gut health with fermented Jatropha curcas cake: Impacts on microbiota, metabolites, and neurotransmitters

Given the escalating global crisis in feed protein availability, Jatropha curcas L. cake has attracted significant interest as a viable alternative protein source in animal feed. This experiment was conducted to investigate the effects of fermented Jatropha curcas L. cake (FJCC) as a protein feed in the diet of pigs. A total of 96 growing pigs with an average weight of 27.60 ± 1.59 kg were divided into three dietary groups with varying FJCC inclusion levels (0, 2.5, and 5%) for a 28 d trial. Results showed that the diet with 5% FJCC (FJCC5) demonstrated significant improvements in average daily gain (p = 0.009), feed-to-gain ratio (p = 0.036), nutrient digestibility, and intestinal morphology. Furthermore, the FJCC5 diet resulted in a decrease in pH values in different gut sections (jejunum p = 0.045, cecum p = 0.001, colon p = 0.012), and favorably altered the profile of short-chain fatty acids (SCFAs) with increased butyric acid content (p = 0.005) and total SCFAs (p = 0.019). Additionally, this diet notably decreased IL-6 levels in the jejunum (p = 0.008) and colon (=0.047), significantly reduced IL-1 levels in the hypothalamus (p < 0.001), and lowered IL-1, IL-6, and IL-10 levels in plasma (p < 0.05). Microbiota and metabolite profile analysis revealed an elevated abundance of beneficial microbes (p < 0.05) and key metabolites such as 4-aminobutyric acid (GABA) (p = 0.003) and serotonin (5-HT) (p = 0.022), linked to neuroactive ligand-receptor interaction. Moreover, FJCC5 significantly boosted circulating neurotransmitter levels of 5-HT (p = 0.006) and GABA (p = 0.002) in plasma and hypothalamus, with corresponding increases in precursor amino acids (p < 0.05). These findings suggest that FJCC, particularly at a 5% inclusion rate, can be an effective substitute for traditional protein sources like soybean meal, offering benefits beyond growth enhancement to gut health and potentially impacting the gut-brain axis. This research underscores FJCC's potential as a valuable component in sustainable animal nutrition strategies.

Understanding microbiome dynamics and functional responses during acidogenic fermentation of sucrose and sugarcane vinasse through metatranscriptomic analysis

Improving anaerobic digestion of sugarcane vinasse - a high-strength wastewater from ethanol distillation - is a subject of great interest, in view of the reduction of the pollutants and recovery of methane and valuable metabolites as byproducts. Through metatranscriptomic analysis, this study evaluated the active microbiome and metabolic pathways in a continuous acidogenic reactor: Stage 1S (control): 100% sucrose-based substrate (SBS); Stage 2SV (acclimation): 50% SBS and 50% vinasse; Stage 3V: 100% vinasse. Metatranscriptome obtained from each Stage was subjected to taxonomic and functional annotations. Under SBS feeding, pH dropped to pH 2.7 and biohydrogen production was observed. As vinasse was added, pH increased to 4.1-4.5, resulting in community structure and metabolite changes. In Stage 3V, biohydrogen production ceased, and propionate and acetate prevailed among the volatile fatty acids. Release of homoacetogenesis enzymes by Clostridium ljungdahlii and of uptake hydrogenase (EC 1.12.99.6) by Pectinatus frisingensis were linked to hydrogen consumption in Stages 2SV and 3V. Metabolic pathways of vinasse compounds, such as carbohydrates, malate, oxalate, glycerol, sulfate and phenol, were investigated in detail. In pyruvate metabolism, gene transcripts of oadA (oxaloacetate decarboxylase) and mdh (malate dehydrogenase), were upregulated in Stage 3V, being mostly attributed to P. frisingensis. Acetate formation from vinasse degradation was mainly attributed to Megasphaera and Clostridium, and propionate formation to P. frisingensis. Glycerol removal from vinasse exceeded 99%, and gene transcripts encoding for glpF (glycerol uptake facilitator protein), glpK (glycerol kinase) and glpABC (glycerol-3-phosphate dehydrogenase) were expressed mostly by Pectinatus and Prevotella. mRNA profiling showed that active bacteria and gene expression greatly changed when vinasse replaced sucrose, and Pectinatus was the main active bacterium degrading the searched compounds from vinasse. The identification of the main metabolic routes and the associated microorganisms achieved in this work contributes with valuable information to support further optimization of fermentation towards the desired metabolites.

Cold exposure, gut microbiota and health implications: A narrative review

Temperature has been recognized as an important environmental factor affecting the composition and function of gut microbiota (GM). Although research on high-temperature impacts has been well studied, knowledge about the effect of cold exposure on GM remains limited. This narrative review aims to synthesize the latest scientific findings on the impact of cold exposure on mammalian GM, and its potential health implications. Chronic cold exposure could disrupt the α-diversity and the composition of GM in both experimental animals and wild-living hosts. Meanwhile, cold exposure could impact gut microbial metabolites, such as short-chain fatty acids. We also discussed plausible biological pathways and mechanisms by which cold-induced changes may impact host health, including metabolic homeostasis, fitness and thermogenesis, through the microbiota-gut-brain axis. Intriguingly, alterations in GM may provide a tool for favorably modulating the host response to the cold temperature. Finally, current challenges and future perspectives are discussed, emphasizing the need for translational research in humans. GM could be manipulated by utilizing nutritional strategies, such as probiotics and prebiotics, to deal with cold-related health issues and enhance well-being in populations living or working in cold environments.

Short term supplementation with cranberry extract modulates gut microbiota in human and displays a bifidogenic effect

Cranberry is associated with multiple health benefits, which are mostly attributed to its high content of (poly)phenols, particularly flavan-3-ols. However, clinical trials attempting to demonstrate these positive effects have yielded heterogeneous results, partly due to the high inter-individual variability associated with gut microbiota interaction with these molecules. In fact, several studies have demonstrated the ability of these molecules to modulate the gut microbiota in animal and in vitro models, but there is a scarcity of information in human subjects. In addition, it has been recently reported that cranberry also contains high concentrations of oligosaccharides, which could contribute to its bioactivity. Hence, the aim of this study was to fully characterize the (poly)phenolic and oligosaccharidic contents of a commercially available cranberry extract and evaluate its capacity to positively modulate the gut microbiota of 28 human subjects. After only four days, the (poly)phenols and oligosaccharides-rich cranberry extract, induced a strong bifidogenic effect, along with an increase in the abundance of several butyrate-producing bacteria, such as Clostridium and Anaerobutyricum. Plasmatic and fecal short-chain fatty acids profiles were also altered by the cranberry extract with a decrease in acetate ratio and an increase in butyrate ratio. Finally, to characterize the inter-individual variability, we stratified the participants according to the alterations observed in the fecal microbiota following supplementation. Interestingly, individuals having a microbiota characterized by the presence of Prevotella benefited from an increase in Faecalibacterium with the cranberry extract supplementation.

Spatial monitoring of hydrolysis in a plug-flow bioreactor: a support for flexible operation?

Hydrolysis at changing hydraulic retention time, recirculation, bedding straw content in the feed, bioaugmentation and the impact of those changes on gradient formation in the liquid phase in plug-flow reactors (PFRs) was examined. The pH-value, conductivity and oxidation-reduction potential (ORP) were monitored at three spots along the PFRs to study potential correlations to process performance during a total process time of 123 weeks. The on-line monitoring showed good correlations to acidogenesis: namely, the pH and ORP to the acidification, to butyric (and lactic) acid concentration and to the acid yield. The ORP (measured at the inlet) showed the most stable correlation to acidogenesis under dynamic operation, while the conductivity (at the outlet) correlated to the acid concentration in dependence on the feedstock. Multiple measurement spots as used in this study allow to gain more information about acidogenic fermentation than a single spot, simplifying process control and automation attempts with recalcitrant feedstock.

Dietary fibre fractions rich in (poly)phenols from orange by-products and their metabolisation by in vitro digestion and colonic fermentation

Orange peel is an interesting by-product because of its composition, particularly its dietary fibre and flavanones. The aim of this work was to extract different fibre fractions from orange peel to obtain potential added-value ingredients and evaluate how the presence of fibre may interfere with (poly)phenol metabolism. Using an aqueous extraction, as a green extraction method, an insoluble fibre fraction (IFF) and a water-soluble extract (WSE) were obtained. Those fractions were analysed to determine the proximate and dietary fibre composition, hydration properties, (poly)phenol composition and antioxidant capacity, comparing the results with the orange peel (OP). The IFF presented the highest content of insoluble dietary fibre and the WSE showed the highest content of (poly)phenols, these being mainly flavanones. An in vitro faecal fermentation was carried out to evaluate the production of short-chain fatty acids (SCFAs) and lactate as prebiotic indicators; the IFF gave the highest production, derived from the greater presence of dietary fibre. Moreover, catabolites from (poly)phenol metabolism were also analysed, phenylpropanoic acids being the major ones, followed by phenylacetic acids and benzoic acids. These catabolites were found in higher quantities in WSE, because of the greater presence of (poly)phenols in its composition. IFF also showed a significant production of these catabolites, which was delayed by the greater presence of fibre. These results reveal that the new ingredients, obtained by an environmentally friendly water extraction procedure, could be used for the development of new foods with enhanced nutritional and healthy properties.

Novel primers to identify a wider diversity of butyrate-producing bacteria

Butyrate-producing bacteria are a functionally important part of the intestinal tract flora, and the resulting butyric acid is essential for maintaining host intestinal health, regulating the immune system, and influencing energy metabolism. However, butyrate-producing bacteria have not been defined as a coherent phylogenetic group. They are primarily identified using primers for key genes in the butyrate-producing pathway, and their use has been limited to the Bacillota and Bacteroidetes phyla. To overcome this limitation, we developed functional gene primers able to identify butyrate-producing bacteria through the butyrate kinase gene, which encodes the enzyme involved in the final step of the butyrate-producing pathway. Genomes extracted from human and rat feces were used to amplify the target genes through PCR. The obtained sequences were analyzed using BLASTX to construct a developmental tree using the MEGA software. The newly designed butyrate kinase gene primers allowed to recognize a wider diversity of butyrate-producing bacteria than that recognized using currently available primers. Specifically, butyrate-producing bacteria from the Synergistota and Spirochaetota phyla were identified for the first time using these primers. Thus, the developed primers provide a more accurate method for researchers and doctors to identify potential butyrate-producing bacteria and deepen our understanding of butyrate-producing bacterial species.

Gut microbiota mediates anxiety-like behaviors induced by chronic infection of Toxoplasma gondii in mice

BACKGROUND

Chronic infection with the neurotropic parasite Toxoplasma gondii (T. gondii) can cause anxiety and gut microbiota dysbiosis in hosts. However, the potential role of gut microbiota in anxiety induced by the parasite remains unclear.

METHODS

C57BL/6J mice were infected with 10 cysts of T. gondii. Antibiotic depletion of gut microbiota and fecal microbiota transplantation experiments were utilized to investigate the causal relationship between gut microbiota and anxiety. Anxiety-like behaviors were examined by the elevated plus maze test and the open field test; blood, feces, colon and amygdala were collected to evaluate the profiles of serum endotoxin (Lipopolysaccharide, LPS) and serotonin (5-hydroxytryptamine, 5-HT), gut microbiota composition, metabolomics, global transcriptome and neuroinflammation in the amygdala. Furthermore, the effects of Diethyl butylmalonate (DBM, an inhibitor of mitochondrial succinate transporter, which causes the accumulation of endogenous succinate) on the disorders of the gut-brain axis were evaluated.

RESULTS

Here, we found that T. gondii chronic infection induced anxiety-like behaviors and disturbed the composition of the gut microbiota in mice. In the amygdala, T. gondii infection triggered the microglial activation and neuroinflammation. In the colon, T. gondii infection caused the intestinal dyshomeostasis including elevated colonic inflammation, enhanced bacterial endotoxin translocation to blood and compromised intestinal barrier. In the serum, T. gondii infection increased the LPS levels and decreased the 5-HT levels. Interestingly, antibiotics ablation of gut microbiota alleviated the anxiety-like behaviors induced by T. gondii infection. More importantly, transplantation of the fecal microbiota from T. gondii-infected mice resulted in anxiety and the transcriptomic alteration in the amygdala of the antibiotic-pretreated mice. Notably, the decreased abundance of succinate-producing bacteria and the decreased production of succinate were observed in the feces of the T. gondii-infected mice. Moreover, DBM administration ameliorated the anxiety and gut barrier impairment induced by T. gondii infection.

CONCLUSIONS

The present study uncovers a novel role of gut microbiota in mediating the anxiety-like behaviors induced by chronic T. gondii infection. Moreover, we show that DBM supplementation has a beneficial effect on anxiety. Overall, these findings provide new insights into the treatment of T. gondii-related mental disorders.

Gut microbiota affects the estrus return of sows by regulating the metabolism of sex steroid hormones

BACKGROUND

Sex hormones play important roles in the estrus return of post-weaning sows. Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota. However, the extent to which the gut microbiota affects estrus return of post-weaning sows is largely unknown.

RESULTS

In this study, we first screened 207 fecal samples from well-phenotyped sows by 16S rRNA gene sequencing and identified significant associations between microbes and estrus return of post-weaning sows. Using metagenomic sequencing data from 85 fecal samples, we identified 37 bacterial species that were significantly associated with estrus return. Normally returning sows were characterized by increased abundances of L. reuteri and P. copri and decreased abundances of B. fragilis, S. suis, and B. pseudolongum. The changes in gut microbial composition significantly altered the functional capacity of steroid hormone biosynthesis in the gut microbiome. The results were confirmed in a validation cohort. Significant changes in sex steroid hormones and related compounds were found between normal and non-return sows via metabolome analysis. An integrated analysis of differential bacterial species, metagenome, and fecal metabolome provided evidence that normal return-associated bacterial species L. reuteri and Prevotella spp. participated in the degradation of pregnenolone, progesterone, and testosterone, thereby promoting estrogen biosynthesis. Furthermore, the microbial metabolites related to sow energy and nutrient supply or metabolic disorders also showed relationships with sow estrus return.

CONCLUSIONS

An integrated analysis of differentially abundant bacterial species, metagenome, and fecal metabolome revealed the involvement of L. reuteri and Prevotella spp. in sow estrus return. These findings provide deep insight into the role of gut microbiota in the estrus return of post-weaning sows and the complex cross-talk between gut microbiota and sex hormones, suggesting that the manipulation of the gut microbiota could be an effective strategy to improve sow estrus return after weaning.

Plant Secondary Compounds Promote White Adipose Tissue Browning via Modulation of the Gut Microbiota in Small Mammals

The browning of white adipose tissue (WAT) is a promising area of research for treating metabolic disorders and obesity in the future. However, studies on plant secondary compounds promoting WAT browning are limited. Herein, we explored the effects of swainsonine (SW) on gut microbiota and WAT browning in captive pikas. SW inhibited body mass gain, increased brown adipose tissue (BAT) mass, and induced WAT browning in pikas. The 16S rDNA sequencing revealed a significant reduction in the alpha diversity and altered community structure of the gut microbiota in captive pikas. However, the addition of SW to the diet significantly increased the alpha diversity of gut microbiota and the relative abundance of Akkermansia, Prevotella, and unclassified_f__Lachnospiraceae, along with the complexity of the microbial co-occurrence network structure, which decreased in the guts of captive pikas. Functional profiles showed that SW significantly decreased the relative abundances of energy metabolism, lipid metabolism, and glycan biosynthesis and metabolism, which were enriched in captive pikas. Furthermore, SW decreased deterministic processes of gut microbiota assembly in July and increased them in November. Finally, the genera Prevotella and unclassified_f__Prevotellaceae were positively correlated with BAT mass. Our results highlighted that plant secondary compounds promote WAT browning by modulating the gut microbiota in small mammals.

Epigallocatechin gallate alleviates osteoporosis by regulating the gut microbiota and serum metabolites in rats

Osteoporosis, one of the serious public health problems worldwide, can lead to degeneration of the bone structure and increased risk of fractures. Epigallocatechin gallate (EGCG) is a natural product with potential efficacy in inhibiting bone loss. However, the specific mechanism remains unclear. This study first investigated the role of EGCG in preventing dexamethasone (DEX)-induced osteoporosis by regulating intestinal microbiota and serum metabolites. We detected the bone density, bone microstructure, and changes in intestinal microorganisms and serum metabolites. According to our results, EGCG inhibited the decline of bone density, protected the bone microstructure, increased microbial diversity, promoted the abundance of beneficial bacteria such as Prevotellaceae and Ruminococcus, and inhibited the abundance of pathogenic bacteria such as Peptostreptococcaceae. There were also significant changes in serum metabolites among different treatments. Differential metabolites were mainly involved in sphingolipid metabolism and glycerophospholipid metabolism pathways, especially ceramide (d18:0/16:0(2OH)), phosphatidylserine (P-20:0/20:4(5Z,8Z,11Z,14Z)), phosphatidylserine (18:2(9Z,12Z)/12:0), and phosphatidylethanolamine (O-16:0/0:00), which were increased after EGCG treatment. Notably, most of the above metabolites were positively correlated with bone mineral density, BV/TV and Tb·Th, and negatively correlated with Tb·Sp. In summary, EGCG can prevent bone damage, promote the production of beneficial bacteria and metabolites, and enhance immune function. This study provides a basis and reference for the prevention and treatment of osteoporosis, as well as the application of EGCG in maintaining body health.

Dietary phosphate disturbs of gut microbiome in mice

Disorder of phosphate metabolism is a common pathological condition in chronic kidney disease patients. Excessive intake of dietary phosphate deteriorates chronic kidney disease and various complications including cardiovascular and infectious diseases. Recent reports have demonstrated that gut microbiome disturbance is associated with both the etiology and progression of chronic kidney disease. However, the relationship between dietary phosphate and gut microbiome remains unknown. Here, we examined the effects of excessive intake of phosphate on gut microbiome. Five-week-old male C57BL/6J mice were fed either control diet or high phosphate diet for eight weeks. Analysis of the gut microbiota was carried out using MiSeq next generation sequencer, and short-chain fatty acids were determined with GC-MS. In analysis of gut microbiota, significantly increased in Erysipelotrichaceae and decreased in Ruminococcaceae were observed in high phosphate diet group. Furthermore, high phosphate diet induced reduction of microbial diversity and decreased mRNA levels of colonic tight junction markers. These results suggest that the excessive intake of dietary phosphate disturbs gut microbiota and affects intestinal barrier function.

Degenerative Cervical Myelopathy induces sex-specific dysbiosis in mice

Degenerative Cervical Myelopathy (DCM) is the most common cause of spinal cord impairment in elderly populations. It describes a spectrum of disorders that cause progressive spinal cord compression, neurological impairment, loss of bladder and bowel functions, and gastrointestinal dysfunction. The gut microbiota has been recognized as an environmental factor that can modulate both the function of the central nervous system and the immune response through the microbiota-gut-brain axis. Changes in gut microbiota composition or microbiota-producing factors have been linked to the progression and development of several pathologies. However, little is known about the potential role of the gut microbiota in the pathobiology of DCM. Here, DCM was induced in C57BL/6 mice by implanting an aromatic polyether material underneath the C5-6 laminae. The extent of DCM-induced changes in microbiota composition was assessed by 16S rRNA sequencing of the fecal samples. The immune cell composition was assessed using flow cytometry. To date, several bacterial members have been identified using BLAST against the largest collection of metagenome-derived genomes from the mouse gut. In both, female and males DCM caused gut dysbiosis compared to the sham group. However, dysbiosis was more pronounced in males than in females, and several bacterial members of the families Lachnospiraceae and Muribaculaceae were significantly altered in the DCM group. These changes were also associated with altered microbe-derived metabolic changes in propionate-, butyrate-, and lactate-producing bacterial members. Our results demonstrate that DCM causes dynamic changes over time in the gut microbiota, reducing the abundance of butyrate-producing bacteria, and lactate-producing bacteria to a lesser extent. Genome-scale metabolic modeling using gapseq successfully identified pyruvate-to-butanoate and pyruvate-to-propionate reactions involving genes such as Buk and ACH1, respectively. These results provide a better understanding of the sex-specific molecular effects of changes in the gut microbiota on DCM pathobiology.

Dietary supplementation of solubles from shredded, steam-exploded pine particles modulates cecal microbiome composition in broiler chickens

This study evaluated the effects of supplementing solubles from shredded, steam-exploded pine particles (SSPP) on growth performances, plasma biochemicals, and microbial composition in broilers. The birds were reared for 28 days and fed basal diets with or without the inclusion of SSPP from 8 days old. There were a total of three dietary treatments supplemented with 0% (0% SSPP), 0.1% (0.1% SSPP) and 0.4% (0.4% SSPP) SSPP in basal diets. Supplementation of SSPP did not significantly affect growth or plasma biochemicals, but there was a clear indication of diet-induced microbial shifts. Beta-diversity analysis revealed SSPP supplementation-related clustering (ANOSIM: r = 0.31, p < 0.01), with an overall lower (PERMDISP: p < 0.05) individual dispersion in comparison to the control group. In addition, the proportions of the Bacteroides were increased, and the relative abundances of the families Vallitaleaceae, Defluviitaleaceae, Clostridiaceae, and the genera Butyricicoccus and Anaerofilum (p < 0.05) were significantly higher in the 0.4% SSPP group than in the control group. Furthermore, the linear discriminant analysis effect size (LEfSe) also showed that beneficial bacteria such as Ruminococcus albus and Butyricicoccus pullicaecorum were identified as microbial biomarkers of dietary SSPP inclusion (p < 0.05; | LDA effect size | > 2.0). Finally, network analysis showed that strong positive correlations were established among microbial species belonging to the class Clostridia, whereas Erysipelotrichia and Bacteroidia were mostly negatively correlated with Clostridia. Taken together, the results suggested that SSPP supplementation modulates the cecal microbial composition of broilers toward a "healthier" profile.

Deep insight into oriented propionate production from food waste: Microbiological interpretation and design practice

Using mixed microbial cultures (MMCs) for oriented volatile fatty acids (VFAs) refining in an open environment is a typical challenge due to the microbial diversiform and the process complexity. Especially for carbohydrate-rich waste (such as food waste), butyrate-type fermentation is usually dominant in a single-stage MMCs anaerobic process, while the production of odd-carbon VFAs (such as propionate) is difficult although it plays a significant role in chemicals industries. In this study, firstly, we gave a new perspective on the rationality of the oriented propionate production using MMCs with lactate as feedstock by conducting in-depth microbial informatics and reaction analysis. Secondly, we verified the feasibility of the "food waste-lactate-propionate" route to reverse the original butyrate-type fermentation situation and explore mechanisms for maintaining stability. In the first stage, a defined lactate fermentation microbiome was used to produce lactate-containing broth (80% of total chemical oxygen demand) at pH=4. In the second stage, an undomesticated undefined anaerobic microbiome was used to drive propionate production (45.26% ± 2.23% of total VFAs) under optimized conditions (C/N = 100:1-200:1 and pH=5.0). The low pH environment in the first stage enhanced the lactic acid bacteria to resist the invasion of non-functional flanking bacteria, making the community stable. In the second stage, the system maintained the propionate-type fermentation due to the absence of the ecological niche of the invasive lactic acid bacteria; The selection of propionate-producing specialists was a necessary but not sufficient condition for propionate-type fermentation. At last, this study proposed an enhanced engineering strategy framework for understanding elaborate MMCs fermentation.

Seasonal variations in acidogenic fermentation of filter primary sludge

Primary treatment of municipal wastewater by rotating belt filtration followed by hydrolysis and acidogenic fermentation of the filter primary sludge (FPS) at ambient temperature was studied at pilot-scale during one year. The seasonal variations of volatile fatty acids (VFAs), nutrient release and soluble COD production as well as microbial community assembly were assessed, leading to novel findings for fermentation at ambient temperature. The reproducibility of VFA production performance was first established by operating the two fermentation reactors under the same conditions, showing similar results regarding VFA production and microbial community structure. One year of operation at 5 d retention time (RT) and 16-29 °C resulted in an average VFA yield of 180±35 mg COD/g VSin and soluble COD yield of 242±40 mg COD/g VSin. The VFA formation was temperature-dependent, with ϴ=1.033±0.005 ( [Formula: see text] . The seasonal variations of the acetic and propionic acid productions were pronounced, whereas the productions of VFAs with longer chains were more stable regardless of temperature. The community structure of the reactor microbiomes was also clearly affected by season and temperature and linked with the production spectrum of VFAs. The ammonium and phosphate releases were stable during the year, leading to a decrease in ratios of soluble COD to NH4+-N and PO43--P during winter. The soluble COD yield was 11% and 27% higher at 5 d RT compared to 3 and 2 d RT respectively, but the corresponding volumetric productivities were lower. The dissimilarities between microbiomes in influent FPS and fermenters were significant even at a short RT of 2 d, and increased with longer RT of 3 and 5 d, primarily caused by selection of bacteria within Bacteroidota in the fermentation reactors.

COVID-19 alters human microbiomes: a meta-analysis

Introduction

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected a substantial portion of the world's population, and novel consequences of COVID-19 on the human body are continuously being uncovered. The human microbiome plays an essential role in host health and well-being, and multiple studies targeting specific populations have reported altered microbiomes in patients infected with SARS-CoV-2. Given the global scale and massive incidence of COVID on the global population, determining whether the effects of COVID-19 on the human microbiome are consistent and generalizable across populations is essential.

Methods

We performed a synthesis of human microbiome responses to COVID-19. We collected 16S rRNA gene amplicon sequence data from 11 studies sampling the oral and nasopharyngeal or gut microbiome of COVID-19-infected and uninfected subjects. Our synthesis included 1,159 respiratory (oral and nasopharyngeal) microbiome samples and 267 gut microbiome samples from patients in 11 cities across four countries.

Results

Our reanalyses revealed communitywide alterations in the respiratory and gut microbiomes across human populations. We found significant overall reductions in the gut microbial diversity of COVID-19-infected patients, but not in the respiratory microbiome. Furthermore, we found more consistent community shifts in the gut microbiomes of infected patients than in the respiratory microbiomes, although the microbiomes in both sites exhibited higher host-to-host variation in infected patients. In respiratory microbiomes, COVID-19 infection resulted in an increase in the relative abundance of potentially pathogenic bacteria, including Mycoplasma.

Discussion

Our findings shed light on the impact of COVID-19 on the human-associated microbiome across populations, and highlight the need for further research into the relationship between long-term effects of COVID-19 and altered microbiota.

Plug-flow hydrolysis with lignocellulosic residues: effect of hydraulic retention time and thin-sludge recirculation

BACKGROUND

Two parallel plug-flow reactors were successfully applied as a hydrolysis stage for the anaerobic pre-digestion of maize silage and recalcitrant bedding straw (30% and 66% w/w) under variations of the hydraulic retention time (HRT) and thin-sludge recirculation.

RESULTS

The study proved that the hydrolysis rate profits from shorter HRTs while the hydrolysis yield remained similar and was limited by a low pH-value with values of 264-310 and 180-200 g_O2 kg_VS^-1 for 30% and 66% of bedding straw correspondingly. Longer HRT led to metabolite accumulation, significantly increased gas production, a higher acid production rate and a 10-18% higher acid yield of 78 g_SCCA kg_VS^-1 for 66% of straw. Thin-sludge recirculation increased the acid yield and stabilized the process, especially at a short HRT. Hydrolysis efficiency can thus be improved by shorter HRT, whereas the acidogenic process performance is increased by longer HRT and thin-sludge recirculation. Two main fermentation patterns of the acidogenic community were found: above a pH-value of 3.8, butyric and acetic acid were the main products, while below a pH-value of 3.5, lactic, acetic and succinic acid were mainly accumulating. During plug-flow digestion with recirculation, at low pH-values, butyric acid remained high compared to all other acids. Both fermentation patterns had virtually equal yields of hydrolysis and acidogenesis and showed good reproducibility among the parallel reactor operation.

CONCLUSIONS

The suitable combination of HRT and thin-sludge recirculation proved to be useful in a plug-flow hydrolysis as primary stage in biorefinery systems with the benefits of a wider feedstock spectrum including feedstock with cellulolytic components at an increased process robustness against changes in the feedstock composition.

Gender Influences Gut Microbiota among Patients with Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disease that affects approximately 11% of the general population. The gut microbiota, among other known factors, plays a substantial role in its pathogenesis. The study aimed to characterize the gut microbiota differences between patients with IBS and unaffected individuals, taking into account the gender aspect of the patients and the types of IBS determined on the basis of the Rome IV Criteria, the IBS-C, IBS-D, IBS-M, and IBS-U. In total, 121 patients with IBS and 70 unaffected individuals participated in the study; the derived stool samples were subjected to 16S rRNA amplicon sequencing. The gut microbiota of patients with IBS was found to be more diverse in comparison to unaffected individuals, and the differences were observed primarily among Clostridiales, Mogibacteriaceae, Synergistaceae, Coriobacteriaceae, Blautia spp., and Shuttleworthia spp., depending on the study subgroup and patient gender. There was higher differentiation of females' gut microbiota compared to males, regardless of the disease status. No correlation between the composition of the gut microbiota and the type of IBS was found. Patients with IBS were characterized by more diverse gut microbiota compared to unaffected individuals. The gender criterion should be considered in the characterization of the gut microbiota. The type of IBS did not determine the identified differences in gut microbiota.

STING Promotes Intestinal IgA Production by Regulating Acetate-producing Bacteria to Maintain Host-microbiota Mutualism

BACKGROUND

Intestinal Immunoglobulin A (IgA) is crucial in maintaining host-microbiota mutualism and gut homeostasis. It has been shown that many species of gut bacteria produce cyclic dinucleotides, along with an abundance of microbiota-derived DNA present within the intestinal lumen, which triggers the tonic activation of the cytosolic cGAS-STING pathway. However, the role of STING in intestinal IgA remains poorly understood. We further investigated whether and how STING affects intestinal IgA response.

METHODS

Intestinal IgA was determined between wild-type (WT) mice and Sting-/- mice in steady conditions and upon enteric Citrobacter rodentium infection. STING agonists were used to stimulating B cells or dendritic cells in vitro. Gut microbiota composition was examined by 16S ribosomal RNA gene sequencing. Bacteria metabolomics functional analyses was performed by PICRUSt2. Fecal short-chain fatty acid (SCFA) was determined by Mass spectrometry and Cedex Bio Analyzer. Gut bacteria from WT mice and Sting-/- mice were transferred into germ-free mice and antibiotic-pretreated mice.

RESULTS

Intestinal IgA response was impaired in Sting-/- mice. However, STING agonists did not directly stimulate B cells or dendritic cells to induce IgA. Interestingly, Sting-/- mice displayed altered gut microbiota composition with decreased SCFA-producing bacteria and downregulated SCFA fermentation pathways. Transfer of fecal bacteria from Sting-/- mice induced less IgA than that from WT mice in germ-free mice and antibiotic-pretreated mice, which is mediated by GPR43. Acetate, the dominant SCFA, was decreased in Sting-/- mice, and supplementation of acetate restored intestinal IgA production in Sting-/- mice.

CONCLUSIONS

STING promotes intestinal IgA by regulating acetate-producing gut bacteria.

Zearalenone attenuates colitis associated colorectal tumorigenesis through Ras/Raf/ERK pathway suppression and SCFA-producing bacteria promotion

The high prevalence of colorectal cancer (CRC) and its leading death causing rate have placed a considerable burden on patients and healthcare providers. There is a need for a therapy that has fewer adverse effects and greater efficiency. Zearalenone (ZEA), an estrogenic mycotoxin, has been demonstrated to exert apoptotic properties when administrated in higher doses. However, it is unclear whether such apoptotic effect remains valid in an in vivo setting. The current study aimed to investigate the effect of ZEA on CRC and its underlying mechanisms in the azoxymethane/ dextran sodium sulfate (AOM/DSS) model. Our results revealed that ZEA significantly lowered the total number of tumours, colon weight, colonic crypt depth, collagen fibrosis and spleen weight. ZEA suppressed Ras/Raf/ERK/cyclin D1 pathway, increasing the expression of apoptosis parker, cleaved caspase 3, while decreasing the expression of proliferative marker, Ki67 and cyclin D1. The gut microbiota composition in ZEA group showed higher stability and lower vulnerability in the microbial community when compared to AOM/DSS group. ZEA increased the abundance of short chain fatty acids (SCFAs) producing bacteria unidentified Ruminococcaceae, Parabacteroidies and Blautia, as well as the faecal acetate content. Notably, unidentified Ruminococcaceae and Parabacteroidies were substantially correlated with the decrease in tumour count. Overall, ZEA demonstrated a promising inhibitory effect on colorectal tumorigenesis and exhibited the potential for further development as a CRC treatment.

The role of gut microbiota on cognitive development in rodents: a meta-analysis

Cognitive function includes learning, remembering and using acquired information. Emerging studies indicate the correlation between microbiota and cognitive function. Higher abundance of a specific gut microbiota, such as Bacteroidetes may improve cognitive abilities. However, another study reported different result. These results suggest that further systematic analysis is required to determine the effect of the gut microbiota abundance on cognitive development. The aim of this study is to summarize the abundance of the specific gut microbiota and cognitive development using meta-analysis. PubMed, ScienceDirect, and Clinical-Key were used as data bases to perform the literature search. Phylum Bacteroidetes, and family Lactobacillaceae were more abundant in cognitive-behavioral enhancement (CBE), whereas Firmicutes, Proteobacteria, Actinobacteria, and family Ruminococcaceae were less abundant in CBE. Differences in gut microbiota abundance are influenced by differences in stage of cognitive dysfunction, intervention, and strain of gut microbiota.

Analysis of gut microbiota in rats with bile duct obstruction after biliary drainage

The abundance of specific gut microorganisms is strongly associated with the concentrations of microbially modified bile acids. This study aimed to investigate the composition of intestinal microbiota in rats subjected to bile duct ligation or biliary drainage. Extrahepatic bile duct ligation was conducted to induce bile duct obstruction in rats. The bile was drained via a percutaneous biliary drainage catheter to cause bile deficiency. The total DNA extracted from fecal samples was sequenced with 16S DNA sequencing. Taxonomic classifications were conducted using the Mothur algorithm and SILVA138 database and were presented along with the abundance presented using a heatmap. The inter- and intra-group differences in the intestinal microbiome composition were analyzed by ANOSIM test. The biomarker microorganisms were screened using the Linear discriminant analysis Effect size method. The possible functional pathways were predicted using the Tax4Fun package. A total of 3277 operational taxonomic units (OTUs) were examined, with 2410 in the Kongbai group, 2236 in the Gengzu group, and 1763 in the Yinliu group. The composition of microorganisms at the levels of phylum, class, order, family, and genus was altered in rats with bile duct obstruction. This composition was then restored by biliary drainage. The top 10 predominant microorganisms were identified that led to the inter-group differences. Functional annotation revealed that the potential functions of the microorganisms with significant differences were enriched in metabolism, cellular processes, and genetic and environmental information processing. The intestinal microbial community was significantly changed in rats with bile duct obstruction. The changes in the abundance of intestinal microbiota Prevotellaceae and Enterobacteriaceae were statistically significant after biliary drainage treatment.

Assessment of aflatoxin exposure, growth faltering and the gut microbiome among children in rural Guatemala: protocol for an observational prospective cohort and bioreactor simulations

INTRODUCTION

Aflatoxin B1 (AFB1) is a carcinogen produced by Aspergillus flavus and Aspergillus parasiticus which grow on maize. Given the high prevalence of child stunting (ie, impaired growth) and other nutritional disorders in low-income and middle-income countries, where maize is consumed, the role of aflatoxin exposure may be significant. Observational reports have demonstrated associations between aflatoxin exposure and impaired child growth; however, most have been cross-sectional and have not assessed seasonal variations in aflatoxin, food preparation and dynamic changes in growth. Biological mechanistic data on how aflatoxin may exert an impact on child growth is missing. This study incorporates a prospective cohort of children from rural Guatemala to assess (1) temporal associations between aflatoxin exposure and child growth and (2) possible mediation of the gut microbiome among aflatoxin exposure, inflammation and child growth.

METHODS AND ANALYSIS

We will prospectively evaluate aflatoxin exposure and height-for-age difference trajectories for 18 months in a cohort of 185 children aged 6-9 months at enrolment. We will assess aflatoxin exposure levels and biomarkers of gut and systemic inflammation. We will examine the faecal microbiome of each child and identify key species and metabolic pathways for differing AFB1 exposure levels and child growth trajectories. In parallel, we will use bioreactors, inoculated with faeces, to investigate the response of the gut microbiome to varying levels of AFB1 exposure. We will monitor key microbial metabolites and AFB1 biotransformation products to study nutrient metabolism and the impact of the gut microbiome on aflatoxin detoxification/metabolism. Finally, we will use path analysis to summarise the effect of aflatoxin exposure and the gut microbiome on child growth.

ETHICS AND DISSEMINATION

Ethics approval was obtained from Arizona State University Institutional Review Board (IRB; STUDY00016799) and Wuqu' Kawoq/Maya Health Alliance IRB (WK-2022-003). Findings will be disseminated in scientific presentations and peer-reviewed publications.

Importance of the female reproductive tract microbiome and its relationship with the uterine environment for health and productivity in cattle: A review

Once thought to be sterile, the reproductive tract microbiome has been characterized due to the transition from culture-dependent identification of bacteria to culture-independent sequencing methods. The urogenital microbiome was first identified in women through the Human Microbiome Project, which led to research in other species such as the bovine. Previous research focused on uterine bacteria associated with postpartum disease, but next generation sequencing methods identified a normal, healthy bacterial community of the reproductive tract of cows and heifers. Bacterial communities are now understood to differ between the uterus and vagina, and throughout the estrous cycle with changes in hormone dominance. In a healthy state, the bacterial communities largely interact with the uterine environment by assisting in maintaining the proper pH, providing and utilizing nutrients and metabolites, and influencing the immunological responses of the reproductive tract. If the bacterial communities become unbalanced due to an increase in potentially pathogenic bacteria, the health and fertility of the host may be affected. Although the presence of a reproductive tract microbiome has become widely accepted, the existence of a placental microbiome and in utero colonization of the fetus is still a popular debate due to conflicting study results. Currently, researchers are evaluating methods to manipulate the reproductive bacterial communities, such as diet changes and utilizing probiotics, to improve reproductive outcomes. The following review discusses the current understanding of the reproductive tract microbiome, how it differs between humans and cattle, and its relationship with the uterine environment.

Dietary Supplementation with Botanical Blends Modified Intestinal Microbiota and Metabolomics of Weaned Pigs Experimentally Infected with Enterotoxigenic Escherichia coli

The objective of this study was to investigate supplementation of botanical blends (BB) comprised of 0.3% capsicum oleoresin and 12% garlic oil on gut microbiota and metabolomic profiles in serum and ileal mucosa of Escherichia coli infected pigs. Sixty weaned pigs were assigned to one of five treatments: negative control (CON-), positive control (CON+), dietary supplementation of 100 ppm BB1, 50 or 100 ppm BB2. All pigs, except CON-, were orally inoculated with 10¹⁰ CFU F18 ETEC/3-mL dose for 3 consecutive days after 7 d adaption. Feces, ileal digesta and cecal content were collected for 16S rRNA amplicon sequencing. Serum and ileal mucosa underwent primary metabolomics analysis. Supplementing 100 ppm BB1 increased (p < 0.05) relative abundances of Enterobacteriaceae and Escherichia-Shigella in ileum, and the relative abundances of Bacteroidota and Prevotellaceae in cecum than CON+ on d 5 post-inoculation (PI). Supplementing 100 ppm BB2 upregulated serum pinitol on d 4 PI and serum cholesterol and aminomalonic acids on d 21 PI, while supplementing 50 ppm BB2 reduced asparagine in ileal mucosa on d 5 PI than CON+. Supplementation with botanical blends modulated ileal and cecal microbiota and serum metabolomics profiles in weaned pigs under Escherichia coli challenge.

Replacing alfalfa hay with industrial hemp ethanol extraction byproduct and Chinese wildrye hay: Effects on lactation performance, plasma metabolites, and bacterial communities in Holstein cows

This trial was designed to investigate the effects of industrial hemp ethanol extraction byproduct (IHEEB) and Chinese wildrye hay (CWH) replacement of alfalfa hay (AH) on digestibility, and lactation performance, plasma metabolites, ruminal fermentation, and bacterial communities in Holstein dairy cows. Nine healthy multiparous Holstein cows (parity = 3) with similar body weights (584 ± 12.3 kg), days in milk (108 ± 11.4), and milk yields (30 ± 1.93 kg; all mean ± standard deviation) were used in a replicated 3 × 3 Latin square design with 3 periods of 21 d. During each period, each group consumed 1 of 3 diets: (1) 0% IHEEB (0IHEEB); (2) 6.0% IHEEB and 1.7% Chinese wildrye hay (6IHEEB); (3) 10.8% IHEEB and 4.3% Chinese wildrye hay (11IHEEB). The diets in each group were isocaloric and isonitrogenous, with similar contents of concentrate and silage but different ratios of IHEEB and CWH to replace AH. The results showed that increasing the substitute did not affect the total-tract apparent nutrient digestibility. There was no difference in lactation performance of dairy cows fed the three diets, except for the cows' somatic cell count (SCC), which decreased with the increase in the amount of the substitute. Cannabidiol and tetrahydrocannabinol were not detected in milk samples of dairy cows in the different treatment groups. 6IHEEB and 11IHEEB-fed cows showed a linear decrease in total volatile fatty acids (VFA) and butyrate compared to the 0IHEEB cows. Plasma IL-1β content quadratically decreased with feeding IHEEB and CWH, and other blood parameters were unaffected. The rumen fluid's relative abundances of Bacteroidota, Fibrobacterota, and Prevotellaceae quadratically increased, while Firmicutes tended to decrease quadratically as the substitution increased. Feeding IHEEB and CWH linearly increased the relative abundances of Firmicutes, Lachnospiraceae, Monoglobaceae, and Butyricicoccaceae in the feces. As the substitution increased, the cost of dairy farming was reduced. In summary, substituting AH with IHEEB and CWH in diets did not affect the total-tract apparent nutrient digestibility, improved milk composition, and plasma immune indices. It changed the bacterial composition in rumen fluid and feces and improved dairy farming benefits.

Effects of second-line anti-tuberculosis drugs on the intestinal microbiota of patients with rifampicin-resistant tuberculosis

Objective

To determine the effects of second-line anti-tuberculosis (TB) drugs on the composition and functions of intestinal microbiota in patients with rifampicin-resistant TB (RR-TB).

Methods

In this cross-sectional study, stool samples and relevant clinical information were collected from patients with RR-TB admitted to the Drug-resistant Specialty Department at Hunan Chest Hospital (Hunan Institute For Tuberculosis Control). The composition and functions of intestinal microbiota were analyzed using metagenomic sequencing and bioinformatics methods.

Results

Altered structural composition of the intestinal microbiota was found when patients from the control, intensive phase treatment, and continuation phase treatment groups were compared (P<0.05). Second-line anti-TB treatment resulted in a decrease in the relative abundance of species, such as Prevotella copri, compared with control treatment. However, the relative abundance of Escherichia coli, Salmonella enterica, and 11 other conditionally pathogenic species increased significantly in the intensive phase treatment group. Based on differential functional analysis, some metabolism-related functions, such as the biosynthesises of phenylalanine, tyrosine, and tryptophan, were significantly inhibited during second-line anti-TB drug treatment, while other functions, such as phenylalanine metabolism, were significantly promoted during the intensive phase of treatment.

Conclusion

Second-line anti-TB drug treatment caused changes in the structural composition of the intestinal microbiota in patients with RR-TB. In particular, this treatment induced a significant increase in the relative abundance of 11 conditionally pathogenic species, including Escherichia coli. Functional analysis revealed significantly decreased biosynthesises of phenylalanine, tyrosine, and tryptophan and significantly increased phenylalanine metabolism.

Preliminary evidence for developing safe and efficient fecal microbiota transplantation as potential treatment for aged related cognitive impairments

Background

Recent studies have reported that gut microbiota is closely associated with cognitive fuction. Fecal microbiota transplantation (FMT) may be a potential treatment for cognitive impairment, but its efficacy in patients with cognitive impairment is unknown.

Objectives

This study aimed to investigate the safety and efficacy of FMT for cognitive impairment treatment.

Methods

Five patients aged 54-80 years (three women) were enrolled in this single-arm clinical trial from July 2021 to May 2022. The Montreal Cognitive Assessment-B (MoCA-B), Activities of Daily Living (ADL), and the cognitive section of the Alzheimer's Disease Assessment Scale (ADAS-Cog) were assessed at days 0, 30, 60, 90, and 180. Additionally, stool and serum samples were obtained twice before FMT was administered and six months after the treatment. The structure of fecal microbiota was analyzed by 16S RNA gene sequencing. Serum samples were analyzed for metabolomics and lipopolysaccharide (LPS)-binding proteins by liquid chromatography-mass spectrometry and enzyme-linked immunosorbent assay, respectively. Safety was assessed based on adverse events, vital signs, and laboratory parameters during FMT and the follow-up period.

Results

The MoCA, ADL, and ADAS-Cog scores of patients with mild cognitive impairment (patients C and E) after FMT were improved or maintained compared with those before transplantation. However, patients with severe cognitive impairment (patients A, B, and D) had no worsening of cognitive scores. Fecal microbiota analysis showed that FMT changed the structure of gut microbiota. The results of serum metabolomics analysis suggested that there were significant changes in the serum metabolomics of patients after FMT, with 7 up-regulated and 28 down-regulated metabolites. 3b,12a-dihydroxy-5a-cholanoic acid, 25-acetylvulgaroside, deoxycholic acid, 2(R)-hydroxydocosanoic acid, and P-anisic acid increased, while bilirubin and other metabolites decreased. KEFF pathway analysis indicated that the main metabolic pathways were bile secretion and choline metabolism in cancer. No adverse effects were reported throughout the study.

Conclusions

In this pilot study, FMT could maintain and improve cognitive function in mild cognitive impairment by changing gut microbiota structure and affecting serum metabolomics. Fecal bacteria capsules were safe. However, further studies are needed to evaluate the safety and efficacy of fecal microbiota transplantation. ClinicalTrials.gov Identifier: CHiCTR2100043548.

The protective effect of Buzhong Yiqi decoction on ischemic stroke mice and the mechanism of gut microbiota

Buzhong Yiqi decoction (BZYQD) has been developed for preventing or reducing the recurrence of ischemic stroke for a long time in China. However, the mechanism of action of the BZYQD is not completely understood. Our research aims to determine whether the mechanism of action of BZYQD is by regulating gut microbiota using 16SR RNA and fecal microbiota transplantation. In a cerebral ischemia mouse model, the results showed that prophylactic administration of BZYQD could reduce brain infarct volume and improve neurological function and behavior. The prophylactic administration of BZYQD could regulate intestinal microbiota and increase the abundance of butyrate-producing Prevotellaceae_NK3B31_group and probiotic Akkermansia in mice 72 h after surgery. Transplanting BZYQD-administered bacterial flora into antibiotic-depleted mice could reproduce the therapeutic effects of BZYQD. Overall, our study provided molecular insights into the mechanism and impact of BZYQD in the prevention of cerebral ischemic damage and highlighted the potential of regulation of intestinal microbiota as a therapeutic approach for ischemic stroke.

Gut microbiota in hypertensive patients with versus without obstructive sleep apnea

We investigated the alteration of gut microbiota and the associated metabolic risks in hypertensive patients with obstructive sleep apnea (OSA) comorbidity. Fecal and blood samples were collected from 52 hypertensive patients, who were divided into three groups: A (controls, apnea-hypopnea index[AHI] < 5, n = 15), B (mild OSA, 5 < AHI < 20, n = 17), and C (moderate-to-severe OSA, AHI > 20, n = 20). The composition of the gut microbiota was studied through 16s RNA sequencing of variable regions 3-4. Analysis of the results revealed that group C had a significant higher concentration of total cholesterol, low-density lipoprotein, and IL-1β compared with group A. The Shannon index showed that bacterial biodiversity was lower in OSA patients. At the phylum level, the ratio of Firmicutes to Bacteroidetes (F/B) was significantly higher in group C than in groups A and B. At the genus level, the relative abundance of short-chain fatty acids (SCFA)-producing bacteria (e.g., Bacteroides and Prevotella) was lower while the number of inflammation-related bacteria (e.g., Lactobacillus) was increased in patients with OSA. We found that the IL-1β level was negatively correlated with Bacteroidetes. The area under the receiver operating characteristic curve was .672 for F/B ratio in determining hypertensive patients with OSA. In patients with hypertension, OSA was associated with worse gut dysbiosis, as evidenced by decreased levels of short-chain fatty acids-producing bacteria and increased number of inflammation-related bacteria. The differences in gut microbiota discriminate hypertensive patients with OSA from those without and may result in an enhanced inflammatory response and increase the risk of metabolic diseases.

Brussels Chicory Stabilizes Unstable Atherosclerotic Plaques and Reshapes the Gut Microbiota in Apoe-/- Mice

BACKGROUND

Adherence to a Mediterranean dietary pattern can protect against atherosclerosis in part by reducing intestinal permeability and gut microbial LPS production. Brussels chicory, a typical Mediterranean vegetable, has been shown to inhibit the formation of early-stage atherosclerosis in mice.

OBJECTIVES

We evaluated whether Brussels chicory affects advanced atherosclerosis progression, intestinal permeability, and gut microbial LPS production.

METHODS

Thirty-week-old male apoE-deficient mice with unstable atherosclerotic plaques in the brachiocephalic artery were fed the AIN-93G diet alone (control) or supplemented with 0.5% freeze-dried Brussels chicory for 20 wk. Plaque volume and features of plaque stability, plaque macrophage polarization, fecal and serum LPS concentrations, serum lipid profiles and inflammation-related cytokines, and gut microbial profiles were measured.

RESULTS

Compared with the control treatment, Brussels chicory consumption did not significantly change plaque volume and serum lipid profiles. However, it increased plaque stability (P < 0.05), as evidenced by reduced necrotic core size (42.3%), and increased fibrous cap thickness (55.0%) and collagen content (68.4%). Moreover, Brussels chicory consumption reduced intestinal permeability (56.3%), fecal and serum LPS concentrations (52.2% and 39.4%), serum IL1β and TNFα (52.0% and 33.8%), promoted plaque macrophage polarization towards the M2-like phenotype, and altered gut microbial composition, the latter indicated by increased relative abundance of certain members of the Ruminococcaceae family, such as Ruminiclostridium_9, Ruminiclostridium_5, and Intestinimonas (P < 0.05). Spearman correlation analyses further showed that these bacterial genera were significantly correlated with intestinal permeability, fecal and serum LPS, serum proinflammatory cytokines, and several features of plaque stability.

CONCLUSIONS

Brussels chicory might help stabilize atherosclerotic plaques in mice by reducing intestinal permeability and gut microbial LPS production. This study provides a promising approach to slow the progression of atherosclerosis.

Yeast-Fermented Rapeseed Meal Extract Is Able to Reduce Inflammation and Oxidative Stress Caused by Escherichia coli Lipopolysaccharides and to Replace ZnO in Caco-2/HTX29 Co-Culture Cells

(1) The present study tested in vitro the capacity of a fermented rapeseed meal extract to reduce medicinal ZnO, which will be banned at the EU level from 2023 onwards because of its potential to cause environmental pollution and the development of Zn resistance in gut bacteria. Rapeseed meal could be an important ZnO substitute as it has antioxidant/radical scavenging properties due to its content of bioactive compounds (e.g., polyphenols). (2) Protein array and flow cytometry were used to detect apoptosis, oxidative stress production, and inflammatory and signaling-related molecules in Caco-2 and goblet HT29-MTX co-culture cells challenged with Escherichia coli lipopolysaccharides and treated with ZnO and FRSM. (3) LPS induced cell death (21.1% vs. 12.7% in control, p < 0.005); apoptosis (16.6%); ROS production; and overexpression of biomarkers related to inflammation (63.15% cytokines and 66.67% chemokines), oxidative stress, and signaling proteins when compared to untreated cells. ZnO was effective in counteracting the effect of LPS, and 73.68% cytokines and 91.67% of chemokines were recovered. FRSM was better at restoring normal protein expression for 78.94% of cytokines, 91.67% of chemokines, and 61.11% of signaling molecules. FRSM was able to mitigate negative effects of LPS and might be an alternative to ZnO in pig diets.

Acidogenic fermentation of food waste in a leachate bed reactor (LBR) at high volumetric organic Loading: Effect of granular activated carbon (GAC) and sequential enrichment of inoculum

This study investigated the impact of different granular activated carbon (GAC) loadings and inoculum enrichment on acidogenic fermentation of food waste in a leachate bed reactor (LBR) operated at a high volumetric organic loading of 49 g VS/L_reactor. LBR with a high GAC loading of 0.51 g GAC/g VS_{food waste} achieved hydrolysis yield of 620 g SCOD/kg VS_added, significantly (P ≤ 0.05) higher to that obtained for LBRs with low or no GAC loading. A high GAC loading also resulted in a higher acidification yield of 507 g COD_SCFA/kg VS_added. Butyrate dominated the short-chain fatty acid (SCFA) composition by constituting 57-60 % of total SCFA at high GAC loadings, while the composition of acetate (38-40 %) and butyrate (36-38 %) were similar at lower GAC loadings. Inoculum enrichment further improved the hydrolysis and acidogenesis yields by 10-22 % resulting in the final hydrolysis yield of 683 g SCOD/kg VS_added and acidification yield of 617 g COD_SCFA/kg VS_added.

Targets of statins intervention in LDL-C metabolism: Gut microbiota

Increasing researches have considered gut microbiota as a new “metabolic organ,” which mediates the occurrence and development of metabolic diseases. In addition, the liver is an important organ of lipid metabolism, and abnormal lipid metabolism can cause the elevation of blood lipids. Among them, elevated low-density lipoprotein cholesterol (LDL-C) is related with ectopic lipid deposition and metabolic diseases, and statins are widely used to lower LDL-C. In recent years, the gut microbiota has been shown to mediate statins efficacy, both in animals and humans. The effect of statins on microbiota abundance has been deeply explored, and the pathways through which statins reduce the LDL-C levels by affecting the abundance of microbiota have gradually been explored. In this review, we discussed the interaction between gut microbiota and cholesterol metabolism, especially the cholesterol-lowering effect of statins mediated by gut microbiota, via AMPK-PPARγ-SREBP1C/2, FXR and PXR-related, and LPS-TLR4-Myd88 pathways, which may help to explain the individual differences in statins efficacy.

Acceleration of lactate-utilizing pathway for enhancing biohydrogen production by magnetite supplementation in Clostridium butyricum

A conductive metal compound can be used as a catalyst for enhancing hydrogen production by dark fermentation. This study aimed to identify mechanisms of enhanced hydrogen production by magnetite supplementation. Experiments were performed with lactate and/or magnetite supplementation to confirm that the lactate-utilizing pathway is the key cause of enhanced hydrogen production. Also, ribonucleic acid sample was collected for monitoring gene regulation under each condition. Hydrogen production was significantly enhanced by approximately 25.6% and 58.9%, respectively, via magnetite alone and with lactate. Moreover, the expression of genes involved in hydrogen production, including pyruvate ferredoxin oxidoreductase, hydrogenase, and ferredoxin, via magnetite alone and with lactate was upregulated by 0.26, 0.71, and 3.50 and 1.06, 2.14, and 1.94 times, respectively.

Simulated elephant colon for cellulose extraction from sugarcane bagasse: An effective pretreatment to reduce chemical use

Sugarcane bagasse (SCB) is an abundant by-product from sugar production and promising biomass for cellulose extraction. Simulated elephant colon pretreatment (SEP) to reduce chemical use in cellulose extraction from SCB was investigated using elephant dung as fermentation inoculum. The 16S rRNA gene sequences showed microorganisms in elephant dung that corresponded to metabolites during pretreatment. Organic acid accumulation in the fermentation broth was confirmed by the presence of lactic, acetic, propionic and butyric acids. Lignin peroxidase, manganese peroxidase and xylanase detected during the pretreatment enhanced lignin removal. The SEP fiber showed increased cellulose content, while lignin content decreased with reduced bleaching time from 7 to 5 h and high whiteness and crystallinity indices. Lignin removal was also confirmed by Fourier transform infrared spectroscopy. Scanning electron microscopy revealed increasing internal surface area through opening up the fiber structure. SEP offered an efficient and promising approach for cellulose fiber extraction with reduced use of chemicals for the bleaching process.

Lactic acid fermentation of food waste at acidic conditions in a semicontinuous system: effect of HRT and OLR changes

Lactic acid production through fermentation is an established technology, however, improvements are necessary to reduce the process costs and to decrease its market price. Lactic acid is used in many industrial sectors and its market has increased in the last decade for its use as the raw material for polylactic acid product. Using food waste as a cheap and renewable substrate, as well as fermentation at uncontrolled pH, helps to make the production cheaper and to simplify the downstream purification process. Lactic acid production at acidic conditions and the role of varying organic loading rate (OLR) and hydraulic retention time (HRT) were tested in two different semicontinuous batch fermentation systems. Reactor performances indicated that lactic acid fermentation was still possible at pH < 3.5 and even up to a pH of 2.95. The highest lactic acid production was recorded at 14-day HRT, 2.14 g VS/L·day OLR, and pH 3.11 with a maximum lactic acid concentration of 8.72 g/L and a relative yield of 0.82 g lactate/g carbohydrates. The fermentation microbial community was dominated by Lactobacillus strains, the organism mainly responsible for lactic acid conversion from carbohydrates. This study shows that low pH fermentation is a key parameter to improve lactic acid production from food waste in a semicontinuous system. Acidic pH favored both the selection of Lactobacillus strains and inhibited VFA producers from utilizing lactic acid as primary substrate, thus promoting the accumulation of lactic acid. Finally, production yields tend to decrease with high OLR and low HRT, while lactic acid production rates showed the opposite trend.

Biorefining food waste through the anaerobic conversion of endogenous lactate into caproate: A fragile balance between microbial substrate utilization and product inhibition

New technologies development and renewable source exploitation are key tools to realize the European Green Deal and to boost the bio-based economy. In this context, fermentation of organic residues as food waste is an efficient method to obtain marketable products such as carboxylic acids widely applied in industrial production. Under favourable thermodynamic conditions, short chain fatty acids deriving from primary fermentation could be biologically converted into medium-chain fatty acids as caproate via chain elongation (CE) process, by using ethanol or lactate as electron donors. This study evaluates the effectivity of producing caproate from Food Waste extract rich in organics with in situ electron donor production. The test carried out at OLR 15 gCOD L^-1d^-1 showed high Volatile Fatty Acids (from acetic to caproic acid) yields (0.37 g g^-1COD_fed), with a maximum caproate concentration of 8 g L^-1. The associated microbiome was composed by lactate-producing bacteria (Corynebacterium, Lactobacillus, and Olsenella) and by chain elongators (Clostridiaceae and Caproiciproducens). By stressing the system with OLR increase up to 20 gCOD L^-1d^-1, the CE process was inhibited by the high concentration of caproate (low occurrence of Clostridiaceae and Caproiciproducens). Nevertheless, after few days of stop-feeding regime imposed to the system, the microbiome restored its capability to proceed with lactate-based CE pathways. Different batch tests carried out with the inhibited biomass at increasing initial caproate concentration confirmed its impact on lactate utilization kinetics.

Gut Microbiota in Psoriasis

Psoriasis is a chronic inflammatory skin disease with autoimmune pathogenic characteristics and is caused by chronic inflammation, which results in uncontrolled keratinocyte growth and defective differentiation. The link between the gut microbiota and immune system regulation opened a novel angle to understand the pathogenesis of many chronic multifactorial diseases, including psoriasis. Current evidence suggests that modulation of the gut microbiota, both through dietary approaches and through supplementation with probiotics and prebiotics, could represent a novel therapeutic approach. The present work aims to highlight the latest scientific evidence regarding the microbiome alterations of psoriatic patients, as well as state of the art insights in terms of microbiome-targeted therapies as promising preventive and therapeutic tools for psoriasis.

The Relationship Between Atrial Fibrillation and Intestinal Flora With Its Metabolites

Atrial fibrillation (AF) is characterized by high morbidity and disability rate. The incidence of AF has rapidly increased due to increased aging population, causing a serious burden on society and patients. Therefore, it is necessary to determine the prevention and treatment of AF. Several studies have assessed the occurrence, development mechanism, and intervention measures of AF. The human gut has several non-pathogenic microorganisms forming the gut flora. The human gut microbiota plays a crucial role in the construction and operation of the metabolic system and immune system. Emerging clinical studies and basic experiments have confirmed that intestinal flora and its metabolites have a role in some metabolic disorders and chronic inflammatory diseases. Moreover, the gut microbiota has a role in cardiovascular diseases, such as hypertension and heart failure. However, the relationship between AF and gut microbiota is unclear. This review summarizes the relevant literature on the relationship between AF and intestinal flora with its metabolites, including Trimethylamine N-Oxide, short-chain fatty acids, lipopolysaccharide and bile acids. Therefore, this review may enhance further development of related research.

The Responses of Lactobacillus reuteri LR1 or Antibiotic on Intestinal Barrier Function and Microbiota in the Cecum of Pigs

This study aimed to investigate responses of the Lactobacillus reuteri or an antibiotic on cecal microbiota and intestinal barrier function in different stages of pigs. A total of 144 weaned pigs (Duroc × Landrace × Yorkshire, 21 days of age) were randomly assigned to the control group (CON, fed with a basal diet), the antibiotic group (AO, fed with basal diet plus 100 mg/kg olaquindox and 75 mg/kg aureomycin), and the L. reuteri group (LR, fed with the basal diet + 5 × 10¹⁰ CFU/kg L. reuteri LR1) throughout the 164-d experiment. A total of 45 cecal content samples (5 samples per group) from different periods (14th, 42th, and 164th days) were collected for 16S rRNA gene amplification. The results revealed that although LR and AO did not change the diversity of cecal microbiota in pigs, the abundance of some bacteria at the genus level was changed with age. The proportion of Lactobacillus was increased by LR in early life, whereas it was decreased by AO compared with the control group. The relative abundance of Ruminococcaceae was increased along with age. In addition, the gas chromatography results showed that age, not AO or LR, has significant effects on the concentrations of SCFAs in the cecum of pigs (P < 0.05). However, the mRNA expression of tight junction proteins zonula occluden-1 (ZO-1) and occludin were increased by AO in the cecum of pigs on day 14, while LR increased the mRNA expression of intestinal barrier-related proteins ZO-1, occludin, mucin-1, mucin-2, PG1-5, and pBD2 in the cecum of pigs on days 14 and 164 (P < 0.05). In conclusion, LR and AO have different effects on the intestinal barrier function of the cecum, and neither LR nor AO damaged the intestinal barrier function of pig cecum. In addition, LR and AO have little effects on cecal microflora in different stages of the pigs. The microflora and their metabolite SCFAs were significantly changed along with age. These findings provide important information to understand the homeostasis of the cecum of pigs after antibiotic or probiotic treatment.

Effects of fucoidans and alginates from Sargassum graminifolium on allergic symptoms and intestinal microbiota in mice with OVA-induced food allergy

Food allergy has been one of the main problems threatening people's health in recent years. However, there is still no way to completely cure it at present. Therefore, the development of food allergy related drugs is still necessary. Sargassum graminifolium (SG) is a kind of polysaccharide rich marine brown alga used in food and medicine. Sargassum graminifolium polysaccharides (SGP) is mainly composed of fucoidans and alginic acid. In our study, we compared the activity of fucoidans and alginates from SG against OVA-induced food allergy in a mouse model, observed the regulatory effects of fucoidans and alginates from SG on the intestinal microbiota and summarized the possible role of the intestinal microbiota in the anti-food allergy process because polysaccharides can further act on the body through the intestinal microbiota. The results showed that fucoidans and alginates from SG could relieve the symptoms of allergy, diarrhea and jejunum injury significantly in mice with food allergy (p < 0.05). Furthermore, fucoidans at 500 mg kg-1 could reduce OVA-specific IgE and TNF-α levels significantly in the serum of food allergic mice (p < 0.05), while alginates could only significantly down-regulate serum OVA-specific IgE (p < 0.05). The results also showed that fucoidans had a stronger regulatory effect on the richness and diversity of the intestinal microbiota in food allergic mice compared to alginates at the same dose. In addition, fucoidans at 500 mg kg-1 had the most significant regulatory effect on Firmicutes, Lactobacillus and Alistipes in food allergic mice. These results suggested that fucoidans and alginates might regulate food allergy in mice through different pathways. Together, this study enriched the research on the action of alga-derived polysaccharides against food allergy.

Metabolic and Microbiome Alterations Following the Enrichment of a High-Fat Diet With High Oleic Acid Peanuts Versus the Traditional Peanuts Cultivar in Mice

A new Israeli-developed peanut cultivar, “Hanoch-Oleic” (HO), uniquely contains enlarged oleic acid contents and was designed to confer additional beneficial effects over the traditional cultivar, “Hanoch” (HN). This work elucidates metabolic changes and microbiota adaptations elicited by HO addition to a high-fat diet (HFD). Male C57BL/6 mice were fed for 18 weeks with a normal diet or a HFD with/without the addition of HN (HFDh) or HO (HFDo). Body-weight did not differ between HFD-fed mice groups, while liver and adipose weight were elevated in the HFDh and HFD groups, respectively. Insulin-sensitivity (IS) was also decreased in these groups, though to a much greater extent in the traditional peanuts-fed group. Modifications in lipids metabolism were evident by the addition of peanuts to a HFD. Liver inflammation seems to return to normal only in HFDh. Peanuts promoted an increase in α-diversity, with HFDo exhibiting changes in the abundance of microbiota that is primarily associated with ameliorated gut health and barrier capacity. In conclusion, the HO cultivar appears to be metabolically superior to the traditional peanut cultivar and was associated with an improved inflammatory state and microbial profile. Nevertheless, IS-negative effects reinforced by peanuts addition, predominantly NH, need to be comprehensively defined.