Relative Abundance Of Firmicutes Research Articles

Effects of moxibustion at "Zusanli" (ST 36) on oxidative stress and intestinal flora in aging rats.

To observe the effects of moxibustion at "Zusanli"(ST 36)on oxidative stress and intestinal flora in subacute aging rats, and to explore the possible mechanism of moxibustion in delaying aging. Thirty SD rats were randomly divided into a blank group, a model group and a Zusanli group, with 10 rats in each group. Subacute aging model was established by intraperitoneal injection of D-galactose at dosage of 500 mg/kg in the model group and the Zusanli group, once a day for 42 days. In the Zusanli group, moxibustion was applied at bilateral "Zusanli" (ST 36) , once a day, 3 moxa cones at each acupoint, for consecutive 28 days. After intervention, the serum levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were detected by ELISA; the intestinal flora was detected by 16S rRNA sequencing technique in each group. Compared with the blank group, the serum level of SOD was decreased (P<0.01), the serum level of MDA was increased (P<0.01) in the model group. Compared with the model group, the serum level of SOD was increased (P<0.01), the serum level of MDA was decreased (P<0.01) in the Zusanli group. Compared with the blank group, Chao1 and Shannon indexes were decreased in the model group (P<0.01, P<0.05). Compared with the model group, Chao1 and Shannon indexes were increased in the Zusanli group (P<0.01, P<0.05). Compared with the blank group, the relative abundance of Firmicutes, Treponema_2 and Lachnospiraceae_NK4A136_group was increased (P<0.05, P<0.01), while the relative abundance of Prevotellaceae_UCG-003 and the relative abundance ratio of Bacteroidetes and Firmicutes (B/F value) were decreased (P<0.01, P<0.05) in the model group. Compared with the model group, the relative abundance of Firmicutes and Treponema_2 was decreased (P<0.01), while the relative abundance of Bacteroidetes, Lactobacillus, Prevotellaceae_UCG-003 and B/F value were increased (P<0.05, P<0.01) in the Zusanli group. Moxibustion at "Zusanli"(ST 36)can effectively improve the level of oxidative stress, regulate the constitution of intestinal flora, maintain the microecological balance of intestinal flora in aging rats, and thus play a role in delaying aging.

Effects of aeration modes and rates on nitrogen conversion and bacterial community in composting of dehydrated sludge and corn straw.

Aeration is an important factor to regulate composting efficiency and nitrogen loss. This study is aimed to compare the effects of different aeration modes (continuous and intermittent) and aeration rate on nitrogen conversion and bacterial community in composting from dehydrated sludge and corn straw. Results showed that the intermittent aeration mode at same aeration volume was superior to the continuous aeration mode in terms of NH3 emission reduction, nitrogen conversion and germination index (GI) improvement. Intermittent aeration mode with 1200 L/h (aeration 5 min, stop 15 min) [K5T15 (V1200)] and 300 L/h of continuous aeration helped to the conservation of nitrogen fractions and accelerate the composting process. However, it was most advantageous to use 150 L/h of continuous aeration to reduce NH3 emission and ensure the effective composting process. The aeration mode K5T15 (V1200) showed the fastest temperature rise, the longer duration of thermophilic stage and the highest GI (95%) in composting. The cumulative NH3 emission of intermittent aeration mode was higher than continuous aeration mode. The cumulative NH3 emission of V300 was 23.1% lower than that of K5T15 (V1200). The dominant phyla in dehydrated sludge and corn straw composting were Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. The dominant phylum in the thermophilic stage was Firmicutes (49.39%~63.13%), and the dominant genus was Thermobifida (18.62%~30.16%). The relative abundance of Firmicutes was greater in the intermittent aeration mode (63.13%) than that in the continuous aeration mode (57.62%), and Pseudomonas was dominant in composting with lower aeration rate and the lowest NH3 emission. This study suggested that adjustment to the aeration mode and rate could affect core bacteria to reduce the nitrogen loss and accelerate composting process.

Adsorption, natural attenuation, and microbial community response of ofloxacin and oxolinic acid in marine sediments

The pollution of quinolone antibiotics in the marine environment has attracted widespread attention, especially for ofloxacin (OFL) and oxolinic acid (OXO) due to their frequent detection. However, few studies have been conducted to assess the behaviors and microbial community response to these antibiotics in marine sediments, particularly for potential antibiotic-resistant bacteria. In this work, the adsorption characteristics, natural attenuation characteristics, and variation of microbial communities of OFL and OXO in marine sediments were investigated. The adsorption process of antibiotics in sediments occurred on the surface and internal pores of organic matter, where OFL was more likely to be transferred from seawater to sediment compared with OXO. Besides, the adsorption of two antibiotics on sediment surfaces was attributed to physisorption (pore filling, electrostatic interaction) and chemisorption (hydrogen bonding). The natural attenuation of OFL and OXO in marine sediment followed second-order reaction kinetics with half-lives of 6.02 and 26.71 days, respectively, wherein biodegradation contributed the most to attenuation, followed by photolysis. Microbial community structure in marine sediments exposure to antibiotics varied by reducing abundance and diversity of microbial communities, as a whole displaying as an increase in the relative abundance of Firmicutes whereas a decrease of Proteobacteria. In detail, Escherichia-Shigella sp., Blautia sp., Bifidobacterium sp., and Bacillus sp. were those antibiotic-resistant bacteria with potential ability to degrade OFL, while Bacillus sp. may be resistant to OXO. Furthermore, functional predictions indicated that the microbial communities in sediment may resist the stress caused by OFL and OXO through cyano-amino acid metabolism, and ascorbate and aldarate metabolism, respectively. The research is key to understanding fate and bacterial resistance of antibiotics in marine sediments.

Bioaccessibility of lead and cadmium in soils around typical lead-acid power plants and their effect on gut microorganisms.

Potentially toxic elements (Pb and Cd) contamination of soil can adversely affect human health. Moreover, these metal ions interact with the gut microbiota after entering the human digestive system. Based on the physiologically based extraction test and the simulator of human intestinal microbial ecosystem, the bioaccessibility of Pb and Cd in soils contaminated with lead-acid power plants was assessed. The gastric stage exhibited the greatest average bioaccessibility of lead and cadmium (63.39% and 57.22%), followed by the small intestinal stage (6.86% and 36.29%); due to gut microorganisms, the bioaccessibility of lead and cadmium was further reduced in the colon stage (1.86% and 4.22%). Furthermore, to investigate soil contamination's effects on gut microbes, 16S rRNA high-throughput sequencing was used to identify the gut microbial species after the colon period. Due to Pb and Cd exposure, the relative abundance of Firmicutes and unidentified_Bacteria decreased, while the relative abundance of Proteobacteria, Synergistota, and Bacteroidota increased. The relationship between environmental factors and the number of microbial species in the gut was also examined using Spearman correlation analysis. Pb and Cd exposure has been found to affect the composition and structure of the gut microbiota.

Studies of peach gum polysaccharide on gut microbiota in vitro fermentation by human feces

Peach gum polysaccharides have multiple biological functions, such as anti-oxidation, blood lipids reduction, and immune protection. However, their impact on the gut microbiota was still unclear. Here, high throughput sequencing was used to study the regulatory effects of peach gum polysaccharide on gut microbiota using an in vitro fermentation model of human gut microbiota. The results showed that gut microbiota species increased significantly and α-diversity index (Sobs, Ace, Chao1, Shannon) decreased significantly after polysaccharide fermentation compared with control group (distilled water). At phylum level, the relative abundance of Firmicutes and Actinomyces increased (61.76% vs. 56.64%, 28.24% vs. 23.11%). In contrast, relative abundance of Bacteroides decreased significantly (8.10% vs. 19.21%). At genus level, the relative abundance of Bifidobacteria, Colinella and Parazobacteria increased significantly (21.43% vs. 19.08%, 6.32% vs. 3.73%, 6.37% vs. 0.00%), while the relative abundance of Bacteroides and Prevotella decreased significantly (3.83% vs. 5.52%, 3.49% vs. 12.15%). Precisely, peach gum polysaccharide can effectively regulate the structure of gut microbiota and has potential probiotic effects including anti-obesity, anti-inflammatory, maintenance of gut epithelial barrier and so on.

Long access heroin self-administration significantly alters gut microbiome composition and structure.

It is well known that chronic opioid use disorder is associated with alterations in gastrointestinal (GI) function that include constipation, reduced motility, and increased bacterial translocation due to compromised gut barrier function. These signs of disrupted GI function can be associated with alterations in the gut microbiome. However, it is not known if long-access opioid self-administration has effects on the gut microbiome. We used 16S rRNA gene sequencing to investigate the gut microbiome in three independent cohorts (N=40 for each) of NIH heterogeneous stock rats before onset of long-access heroin self-administration (i.e., naïve status), at the end of a 15-day period of self-administration, and after post-extinction reinstatement. Measures of microbial α- and β-diversity were evaluated for all phases. High-dimensional class comparisons were carried out with MaAsLin2. PICRUSt2 was used for predicting functional pathways impacted by heroin based on marker gene sequences. Community α-diversity was not altered by heroin at any of the three phases by comparison to saline-yoked controls. Analyses of β-diversity showed that the heroin and saline-yoked groups clustered significantly apart from each other using the Bray-Curtis (community structure) index. Heroin caused significant alterations at the ASV level at the self-administration and extinction phases. At the phylum level, the relative abundance of Firmicutes was increased at the self-administration phase. Deferribacteres was decreased in heroin whereas Patescibacteria was increased in heroin at the extinction phase. Potential biomarkers for heroin emerged from the MaAsLin2 analysis. Bacterial metabolomic pathways relating to degradation of carboxylic acids, nucleotides, nucleosides, carbohydrates, and glycogen were increased by heroin while pathways relating to biosynthesis of vitamins, propionic acid, fatty acids, and lipids were decreased. These findings support the view that long access heroin self-administration significantly alters the structure of the gut microbiome by comparison to saline-yoked controls. Inferred metabolic pathway alterations suggest the development of a microbial imbalance favoring gut inflammation and energy expenditure. Potential microbial biomarkers and related functional pathways likely invoked by heroin self-administration could be targets for therapeutic intervention.

Effects of Isochlorogenic Acid on Ewes Rumen Fermentation, Microbial Diversity and Ewes Immunity of Different Physiological Stages.

The effects of isochlorogenic acid (ICGA) on ewes rumen environment, microbial diversity, and immunity at different physiological stages (estrus, pregnancy and lactation) were studied in this experiment. Twenty healthy female Hu lambs of 1.5 months with similar body weight (17.82 ± 0.98 kg) and body condition were selected and randomly divided into two groups: the control group (CON) and the ICGA group (ICGA). The lambs of CON were fed a basal diet, while the lambs of ICGA were supplemented with 0.1% ICGA based on the basal diet. Lambs rumen fermentation characteristics, microbial diversity and immunity at estrus, pregnancy, and lactation stages were determined and analyzed, respectively. The results showed that the rumen pH in CON increased first and then decreased as lambs grew (p < 0.05). However, it showed the opposite change in ICGA. The content of ammonia nitrogen (NH3-N) showed the highest at estrus stage in both groups, but it was significantly higher in ICGA than that in CON (p < 0.05). The Acetic acid/propionic acid (A/P) ratio at estrus stage and the volatile fatty acids (VFAs) at pregnancy stage in ICGA were significantly higher than those of the CON (p < 0.05). The 16S rDNA sequencing analysis showed that the Shannon, Chao 1 and ACE indexes of the ICGA were significantly higher than those of the CON both at estrus and lactation stages (p < 0.05), while they showed higher at the pregnancy stage in CON (p > 0.05). Principal component analysis (PCA) showed that there were significant differences in rumen microorganism structure between CON and ICGA at all physiological stages (p < 0.01). At the phylum level, compared with the CON, Firmicutes relative abundance of three physiological stages decreased (p > 0.05) while Bacteroidota increased (p > 0.05). The relative abundance of Synergistota at estrus stage and Patescibacteria at the lactation stage increased significantly too (p < 0.05). At the genus level, compared with the CON, the relative abundance of Prevotella at three stages showed the highest (p > 0.05), while the relative abundance of Succiniclasticum, unclassified_Selenomonadaceae and Rikenellaceae_RC9_gut_group showed different abundances at different physiological stages in ICGA. Compared with the CON, the lambs of the ICGA showed higher blood IgG, IgM, and TNF- α contents at three physiological stages and higher IL-6 contents at pregnancy stage (p < 0.05). Conclusion: Adding ICGA could regulate ewes rumen fermentation mode at different physiological stages by increasing rumen NH3-N at estrus, VFAs at pregnancy, and the ratio of A/P at lactation. It optimizes rumen microbial flora of different physiological stages by increasing Bacteroidota relative abundance while reducing Firmicutes relative abundance, maintaining rumen microbial homeostasis at pregnant stage, increasing the number of beneficial bacteria in later lactating and ewes blood immunoglobulins content at three physiological stages.

Mechanism of sturgeon intestinal inflammation induced by Yersinia ruckeri and the effect of florfenicol intervention

The mechanism by which Y. ruckeri infection induces enteritis in Chinese sturgeon remains unclear, and the efficacy of drug prevention and control measures is not only poor but also plagued with numerous issues. We conducted transcriptomic and 16 S rRNA sequencing analyses to examine the differences in the intestinal tract of hybrid sturgeon before and after Y. ruckeri infection and florfenicol intervention. Our findings revealed that Y. ruckeri induced the expression of multiple inflammatory factors, including il1β, il6, and various chemokines, as well as casp3, casp8, and multiple tumor necrosis factor family members, resulting in pathological injury to the body. Additionally, at the phylum level, the relative abundance of Firmicutes and Bacteroidota increased, while the abundance of Plesiomonas and Cetobacterium decreased at the genus level, altering the composition of the intestinal flora. Following florfenicol intervention, the expression of multiple apoptosis and inflammation-related genes was down-regulated, promoting tissue repair. However, the flora became further dysregulated, increasing the risk of infection. In conclusion, our analysis of the transcriptome and intestinal microbial composition demonstrated that Y. ruckeri induces intestinal pathological damage by triggering apoptosis and altering the composition of the intestinal microbiota. Florfenicol intervention can repair pathological damage, but it also exacerbates flora imbalance, leading to a higher risk of infection. These findings help elucidate the molecular mechanism of Y. ruckeri-induced enteritis in sturgeon and evaluate the therapeutic effect of drugs on intestinal inflammation in sturgeon.

Effects of Whole-Plant Corn Silage on Growth Performance, Serum Biochemical Indices, and Fecal Microorganisms in Hezuo Pigs.

In this study, we investigated the effects of the dietary inclusion of different proportions of whole-plant corn silage on growth performance, serum biochemical indexes, and intestinal microorganisms in Hezuo pigs. Thirty-two two-month-old Hezuo pigs (body weight: 7.88 ± 0.81 kg) were randomly divided into four groups of eight pigs (half male, half female) each. The control (CON) group received a basal diet, while the three experimental groups were fed the basal diet, part of which had been replaced with 5%, 10%, and 15% whole-plant corn silage, respectively. The experiment lasted for 127 days, including 7 days of pre-testing and 120 days of formal testing. At the end of the experiment, blood and fecal samples were collected. Compared with the CON group, the feed-to-gain ratio was significantly lower in the 10% test group (p < 0.05), whereas the total protein, albumin, triglyceride, and glucose contents were significantly higher (p < 0.05). No significant differences in total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, creatinine, urea, aspartate aminotransferase, and alanine aminotransferase were observed among the groups (p > 0.05). The addition of whole-plant corn silage to the diet significantly increased alpha diversity in the pig gut based on 16S rRNA gene sequencing. The principal coordinate analysis results showed significant clustering of the different groups (p < 0.05). At the phylum level, the addition of whole-plant corn silage to the diet significantly decreased (p < 0.05) the relative abundance of Firmicutes and significantly increased (p < 0.05) that of Bacteroidetes. At the genus level, the relative abundance of Streptococcus significantly decreased (p < 0.05) with increasing silage supplementation levels, whereas species diversity significantly increased (p < 0.05). In conclusion, 10% is the recommended inclusion ratio for whole-plant corn silage in the diets of pigs.

Traditional Chinese medicine (Xielikang) reduces diarrhea symptoms in acquired immune deficiency syndrome (AIDS) patients by regulating the intestinal microbiota.

Diarrheal acquired immune deficiency syndrome (AIDS) seriously affects the quality of life of patients. In this study, we analyzed the differences in the intestinal microbiota among healthy individuals, AIDS patients without diarrhea and AIDS patients with diarrhea through high-throughput sequencing. The microbial diversity in the intestines of patients in the AIDS diarrhea group was significantly increased, and after treatment with Xielikang, the intestinal microbial diversity returned to the baseline level. At the phylum level, compared those in to the healthy (ZC) and AIDS non diarrhea (FN) groups, the relative abundances of Bacteroidetes and Verrucomirobia in the AIDS diarrhea (FA) group before treatment were significantly increased, while the relative abundance of Firmicutes was significantly decreased. Similarly, compared with those in the FA group, the relative abundances of Bacteroidea and Firmicutes in the AIDS diarrhea (FB) group after treatment were significantly increased, while the relative abundance of Firmicutes was significantly decreased after treatment. Additionally, there was no significant difference between the ZC and FN groups. At the genus level, compared with those in the ZC group, the relative abundance of Prevotella and Escherichia_Shigella in the FA group was significantly increased, while the relative abundances of Megamonas and Bifidobacterium was significantly decreased compared to that in the ZC group. After treatment with Xielikang, the relative abundance of Prevotella and Escherichia_Shigella in the FB group were significantly decreased, while the relative abundances of Megamonas and Bifidobacteria were significantly increased than those in the FA group; moreover, there was no significant difference between the ZC and FN groups. The functional prediction results showed that the ketodeoxyoctonate (Kdo) transfer to lipid IVA III and the superpathway of N-acetylglucosamine pathways in the AIDS diarrhea group were significantly altered. The correlation analysis results showed that Dorea was positively correlated with inflammatory factors, while Streptococcus and Lactobacillus were negatively correlated with inflammatory factors. The composition and function of the intestinal microbiota changed significantly in AIDS diarrhea patients, which affected the immune function of the host. The Xielikang capsule modulated the composition of the intestinal microbiota in AIDS diarrhea patients and thus improved immune function and reduced diarrheal symptoms.

Effects of dietary supplementation with Haematococcus pluvialis on the growth, antioxidantase activities, and gut microbiota of Chinese mitten crab (Eriocheir sinensis)

AbstractThe Chinese mitten crab (Eriocheir sinensis) is bred extensively in Eastern and Northern China and faces a series of problems such as frequent diseases, germplasm degradation, and declining benefits, which have appeared to seriously affect the sustainable development of the cultivation industry. Haematococcus pluvialis, a type of unicellular green algae, have been proven to be the suitable dietary supplementation in crustacean feeds. After 14 days of feeding with 5% dietary supplementation with Haematococcus pluvialis powder, the growth, antioxidantase activities, and gut microbiota of E. sinensis were analyzed. The results indicated that H. pluvialis powder could significantly improve growth indicators including weight gain rate (WGR) and specific growth rate (SGR) of E. sinensis (p &lt; 0.05). The levels of superoxide dismutase (SOD) and catalase (CAT) declined, while that of phenoloxidase (PO) kept rising under the treatment of H. pluvialis powder. Moreover, alkaline phosphatase (AKP) activity dropped initially and then increased. No significant differences in the Simpson index and Chao1 index in the control and H. pluvialis powder treatment were observed (p &gt; 0.05). Although the dominant microbiota in the crab gut were not affected significantly by H. pluvialis powder, significant differences in the relative abundance of the dominant phyla between the control and H. pluvialis powder treatment groups were observed (p &lt; 0.05). Furthermore, the relative abundance of Firmicutes and Candidatus_Bacilloplasma, which play an important role in the life activities of E. sinensis, were significantly higher in the group treated by H. pluvialis powder than in the control (p &lt; 0.05). Therefore, the H. pluvialis powder could be potentially used not only as a rapid fattening regulator, but also to improve the immunity and metabolic capacity of E. sinensis.

Impact of agitation and non-agitation on microbiota and reactor performance in anaerobic digestion

Optimizing process conditions in anaerobic digestion could enhance the utilization of organic matter for renewable energy generation. Thus, initial upset substrates with elevated volatile fatty acids were investigated under agitation and non-agitation conditions for optimal bioreactor performance. There were two continuous agitation scenarios for the liquid-state (40 and 100 rpm) with a non-agitated scenario. Similarly, a non-agitated and 40 rpm scenario for the solid-state. The result indicated that the non-agitated liquid-state reactor had the highest methane yield (193 L/kgVS) and lowest retention (51 days) despite delayed microbial adaptation. Of the prominent microbes, the relative abundance of Firmicutes and Archaea_unclassified negatively correlated with VFA at 100 rpm. Contrarily at 40 rpm, Firmicutes correlated positively with VFA, an indication that Firmicutes could withstand acid production at agitation speed ≤40 rpm suggesting that agitation associated with VFA might reduce microbial diversity in an initial upset liquid-state bioreactor. Thus, upset influent could be utilized for energy generation with a non-agitated liquid-state bioreactor.

Effects of citric acid on arsenic transformation and microbial communities in different paddy soils

Root exudate is a major source of soil organic matter and can significantly affect arsenic (As) migration and transformation in paddy soils. Citric acid is the main component of rice root exudate, however, the impacts and rules of citric acid on As bioavailability and rhizobacteria in different soils remains unclear. This study investigated the effects of citric acid on As transformation and microbial community in ten different paddy soils by flooded soil culture experiments. The results showed that citric acid addition increased total As and arsenate (As(V)) in the soil porewater by up to 41-fold and 65-fold, respectively, after 2-h incubation. As(V) was the main As species in soil porewater within 10 days with the addition of citric acid. Non-specifically sorbed As of soils, total Fe and total As were the main environmental factors affecting the soil microbial communities. High-throughput sequencing analysis demonstrated that citric acid addition significantly altered the soil microbial community structure, shifting the Proteobacteria-related reducing bacteria to Firmicutes-related reducing bacteria in different paddy soils. The relative abundance of Firmicutes was promoted by 174–196%. Clostridium-related bacteria belonging to Firmicutes became the dominant genera, which is believed to regulate As release through the reductive dissolution of iron oxides or the direct reduction of As(V) to arsenite (As(III)). However, citric acid addition significantly decreased the relative abundance of Geobacter and Anaeromyxobacter, which are also typical active As(V)- and ferric-reducing bacteria. Real-time quantitative polymerase chain reaction (qPCR) also revealed that the addition of citric acid significantly decreased the relative abundances of Geobacter in the different soils by 8–28 times while the relative abundances of Clostridium increased by 2–5 times. These results provide significant insight on As transformation in different types of rice rhizospheric soils and guidance for the application of rice varieties with low citric acid exuding to restrict As accumulation.

Impact of repeated fumigant applications on soil properties, crop yield, and microbial communities in a plastic-mulched tomato production system

Pre-plant soil fumigation is widely applied to control nematodes, soil-borne fungal pathogens, and weeds in vegetable crops. However, most of the research evaluating the effect of fumigants on crop yield and soil microbial communities has been done on single compounds despite growers mainly applying fumigant combinations. We studied the effect of different fumigant combinations (chloropicrin, 1,3-dichloropropene, and metam potassium) on soil properties, crop yield, and the soil bacterial and fungal microbiome for two consecutive years in a plastic-mulched tomato production system in Florida (United States). While combinations of fumigants did not improve plant productivity more than the individual application of these products, application of fumigants with >60 % chloropicrin did significantly increase yield. Fumigant combinations had no significant effect on bacterial diversity, but fumigants with >35 % chloropicrin reduced soil fungal diversity and induced temporary changes in the soil bacterial and fungal community composition. These changes included short-term increases in the relative abundance of Firmicutes and Ascomycota, as well as decreases in other bacterial and fungal taxa. Repeated fumigation reduced network complexity and the relative abundance of several predicted bacterial functions and fungal guilds, particularly after fumigation and at end of harvest (3-months post fumigation). A structural equation model (SEM) showed fumigants not only directly impact crop yield, but they can also indirectly determine variations in plant productivity through effects on the soil microbiome. Overall, this study increases our understanding of the environmental and agricultural impacts of fumigants in a plastic-mulched tomato production system.

Gut microbiota changes associated with low-carbohydrate diet intervention for obesity.

Low-carbohydrate diets (LCDs) are frequently recommended for alleviating obesity, and the gut microbiota plays key roles in energy metabolism and weight loss. However, there is limited in-human research on how LCD changes gut microbiota. In this before-after study, 43 participants were assigned to the LCD intervention for 4 weeks. The main objective was to investigate the specific changes that occur in the participants' microbiome in response to the LCD. Changes in gut microbiota were analyzed using 16s rRNA sequencing. Body composition was measured using InBody 770. Remarkably, 35 participants (79.07%) lost more than 5% of their body weight; levels of BMI, body fat, and total cholesterol were significantly decreased, indicating the effectiveness of the LCD intervention. The richness of microbiota significantly increased after the intervention. By taking the intersection of ANOVA and linear discriminant analysis effect size (LEfSe) analysis results, we identified three phyla, three classes, four orders, five families, and six genera that were differentially enriched between baseline and week-4 time points. Among the three phyla, relative abundances of Firmicutes and Actinobacteriota decreased significantly, while Bacteroidetes increased significantly. At the genus level, Ruminococcus, Agathobacter, Streptococcus, and Bifidobacterium showed a significant reduction in relative abundances, whereas Parabacteroides and Bacteroides increased steadily. Our results demonstrate that LCD can effectively alleviate obesity and modify certain taxa of gut microbiota, providing potential insights for personalized dietary interventions against obesity.

P1213 The effects of Escherichia coli Nissle 1917 on the gut microbiota composition in ulcerative colitis patients

Abstract Background Escherichia coli Nissle (EcN) 1917 is a Gram-negative bacterium currently used as probiotic in the management of infectious gastroenteritis and ulcerative colitis (UC). We evaluated the effect of administration of EcN on the composition of the gut microbiota and on intestinal permeability in patients affected by UC. Methods Five patients with stable UC were treated with EcN one pill daily for ten days followed by two pills per day for further twenty days. Fecal samples were collected before the treatment (T0), after ten days (T1) and after one month of treatment (T2). Alpha diversity, microbiota composition and taxonomy were analyzed. Results Alpha diversity increased through treatment: Good’s coverage index revealed an increase in the number of operational taxonomic units (OTUs) at T2. At phylum taxonomic level, Firmicutes relative abundance decreased at T1 compared to T0. At family level, Clostridiacae relative abundance at T1 was higher than T0 and T2. The T test on gut microbiota variations at species level reveals the variability at the two timepoints (T0 and T2), with significant increase for Actinomyces, Anaerostipes, Bacteroides, Bulleidia, Corynebacterium, Dialister, Enterobacteriaceae, Erysipelotrichaceae, Finegoldia, Granulicatella, Lactobacillaceae, Peptoniphilus, Phascolarctobacterium, Roseburia, Serratia, Veillonellaceae, Veillonella dispar. Furthermore, the administration of EcN improved intestinal permeability, assessed on a CaCO2 monolayer. Conclusion Treatment with EcN leads to an improvement in the qualitative composition of the gut microbiota in patients affected by UC, in terms of both diversity and taxonomy. These effects are stronger at the end of treatment.

Effects of Aquaculture and Thalassia testudinum on Sediment Organic Carbon in Xincun Bay, Hainan Island

Eutrophication due to aquaculture can cause the decline of seagrasses and impact their carbon storage capacity. This study explored the effects of aquaculture on the sediment organic carbon (SOC) in Thalassia testudinum seagrass beds using enzyme activity and microorganisms as indicators. Our results showed that the distance to aquaculture significantly increased the SOC and TN of sediments; the C/N ratio of sediments was reduced by the distance to aquaculture. Distance to aquaculture and seagrasses significantly impacted the δ13C of sediments, and their significant interactive effects on the δ13C of sediments were found. Distance to aquaculture and seagrasses had significantly interactive effects on the cellulase activity of sediments. Distance to aquaculture and seagrasses separately reduced the invertase activity of sediments. SOC in the seagrass bed was significantly positively impacted by cellulase activity and polyphenol oxidase activity in sediments. Firmicutes, Desulfobacterota and Chloroflexi were the dominant taxa in the S1 and S2 locations. From the S1 location to the S2 location, the relative abundances of Firmicutes and Desulfobacterota increased. The functional profiles of COG were relatively similar between the S1 and S2 locations. BugBase phenotype predictions indicated that the microbial phenotypes of all the seagrass sediment samples were dominated by anaerobic bacteria in terms of oxygen utilizing phenotypes. FAPROTAX functional predictions indicated that aquaculture affects functions associated with seagrass bed sediment bacteria, particularly those related to carbon and nitrogen cycling. This study can provide an important basis for understanding the response mechanism of global carbon sink changes to human activities such as aquaculture and supply more scientific data for promoting the conservation and management of seagrass beds.

Rhodiola rosea L. improved intestinal digestive enzyme activities, inflammatory response, barrier and microbiota dysbiosis in Lateolabrax maculatus juveniles fed with high-carbohydrate diets

A 56-d feeding trial was conducted to evaluate the influences of Rhodiola rosea L. on digestive enzyme activities, intestinal barrier, inflammatory response, and microbiota dysbiosis in Lateolabrax maculatus juveniles (9.37 ± 0.03 g) fed with high-carbohydrate diets. Six diets were designed: a control diet (20% corn starch, Control), high-carbohydrate diet (30% corn starch, HC1), and four high-carbohydrate diets supplemented with Rhodiola rosea L. at 30, 60, 90 and 120 mg/kg (HC2, HC3, HC4 and HC5, respectively). Compared with the control group, the HC1 diet remarkably increased α-amylase, lipase, and chymotrypsin activities in the intestine (p < 0.05), as well as the mRNA levels of Claudin-15, NF-κB, TNF-α, IL-1β, and IL-8 (p < 0.05) and the relative abundance of Proteobacteria and Photobacterium in the intestine, which belong to the phylum and genus level, respectively. But the opposite trend was found in muscular thickness and villus lengths (p < 0.05), the mRNA levels of Occludin, ZO-1, and TGF-β (p < 0.05), at the level of phylum and genus level in the HC1 group, and the relative abundance of Firmicutes, Bacteroidetes, and Bacillus in the intestine compared with the control group. Intestinal chymotrypsin activity was significantly higher in the HC3 group and intestinal muscular thickness and villus lengths were also significantly higher in the HC2, HC3, HC4, and HC5 groups compared to the HC1 group (p < 0.05). In addition, Occludin mRNA expression in the intestine was significantly increased in the HC2, HC4, and HC5 groups compared to the HC1 group. ZO-1 and TGF-β mRNA expression in the intestine were significantly increased in the HC2, HC3, HC4, and HC5 groups compared to the HC1 group (p < 0.05). At the phylum level, the relative abundance of Firmicutes and Bacteroidetes was higher in the intestine in the HC2, HC3, HC4, and HC5 groups than that in the HC1 group. On the contrary, intestinal lipase and chymotrypsin activities were significantly decreased in the HC2 group compared to the HC1 group, respectively (p < 0.05). The Claudin-15, NF-κB, TNF-α, IL-1β, and IL-8 mRNA expression in the intestine were significantly decreased in the HC2, HC3, HC4, and HC5 groups compared to the HC1 group (p < 0.05). Besides, at the genus level, compared to the HC1 group, the relative abundance of Photobacterium in the intestine and the diversity of the intestinal microbiota in the HC2, HC3, HC4, and HC5 groups were all decreased. In conclusion, these results demonstrated that the addition of Rhodiola rosea L. in high-carbohydrate diets can improve intestinal digestive enzyme activities, inflammatory response and intestinal barrier-related gene expression, and microbiota dysbiosis in L. maculatus. The suitable supplemental level of Rhodiola rosea L. in high-carbohydrate diets of L. maculatus is 60 mg/kg.

Evaluation of corn fermented protein on the fecal microbiome of cats.

Co-products from the ethanol industry, such as distillers dried grains with solubles (DDGS), can provide alternative protein sources for pet food. Corn fermented protein (CFP) is produced using postfermentation technology to split the protein and yeast from fiber prior to drying. This results in a higher protein ingredient compared to DDGS, increasing its appeal for pet food. In addition, the substantial yeast component, at approximately 20% to 25%, may promote gut health through modulation of the microbiome and the production of short-chain fatty acids. Therefore, the objective of this study was to determine the effect of CFP on the fecal microbiome of cats. The 4 experimental diets included a control with no yeast (T1) and diets containing either 3.5% brewer's dried yeast (T2), 2.5% brewer's dried yeast plus 17.5% DDGS (T3), or 17.5% CFP (T4). All diets except T1 were formulated to contain 3.5% yeast. Diets were fed to adult cats (n = 11) in an incomplete 4 × 4 replicated Latin square design. Cats were adapted to diet for 9 d followed by a 5-d total fecal collection. During each collection period, fresh fecal samples from each cat were collected and stored at -80 °C until analysis. Fresh fecal samples (n = 44) were analyzed by 16S rRNA gene sequencing. Raw sequences were processed through Mothur (v.1.44.1). Community diversity was evaluated in R (v4.0.3). Relative abundance was analyzed within the 50 most abundant operational taxonomic unitsusing a mixed model of SAS (v9.4, SAS Institute, Inc., Cary, NC). Diet was the fixed effect and cat and period were random effects. Results were considered significant at P < 0.05. Alpha-diversity indices (Observed, Chao1, Shannon, Simpson) and beta-diversity metric (principal coordinate analysis) were similar for all treatments. Predominant phyla were Firmicutes (66%), Bacteroidetes (25%), Actinobacteria (8%), Proteobacteria (0.64%), and Desulfobacteria (0.54%). The relative abundance of Firmicutes and Actinobacteria was lower (P < 0.05) for T3 compared to T4 and T2, respectively. On a more specific phylogenic level, 17 genera resulted in differences (P < 0.05) among dietary treatments. Overall, this data indicates that compared to traditional yeast and distillers dried grains, CFP did not alter the overall diversity of the fecal microbiome of healthy adult cats over a 14-d period.

Oxidized konjac glucomannan: A safe dietary fiber influencing mouse gut microbiota

In this 13-week study, the potential effects of oxidized konjac glucomannan (OKGM) on ICR mice's metabolic health and gut microbiota were investigated and contrasted with enzyme-hydrolyzed KGM (EKGM) at a same molecular weight. Mice were fed diets containing 0 %, 2.5 %, 5.0 %, and 7.5 % of OKGM for 13 weeks. Results indicated that OKGM induced no adverse effects, with overall health, body weight gain, food consumption, and clinical pathology parameters being comparable to the control group. The no-observed-adverse-effect-level for OKGM was determined at 7.5 % in the diet, corresponding to 10.21 and 12.01 g/kg/day for male and female mice, respectively. OKGM intake positively regulated gut microbiota, characterized by a reduction in the relative abundance of Firmicutes, an increase in Bacteroidetes, and an enhanced presence of Lactobacillus, particularly Lactobacillus reuteri. In comparison, EKGM differently modulated the microbiota, notably increasing Muribaculaceae. These findings suggest that OKGM has the potential to be a functional food additive.