Abundance Of Butyrate-producing Bacteria Research Articles

Alterations in gut microbiota contribute to cognitive deficits induced by chronic infection of Toxoplasma gondii

Chronic infection with Toxoplasma gondii (T. gondii) emerges as a risk factor for neurodegenerative diseases in animals and humans. However, the underlying mechanisms are largely unknown. We aimed to investigate whether gut microbiota and its metabolites play a role in T. gondii-induced cognitive deficits. We found that T. gondii infection induced cognitive deficits in mice, which was characterized by synaptic ultrastructure impairment and neuroinflammation in the hippocampus. Moreover, the infection led to gut microbiota dysbiosis, barrier integrity impairment, and inflammation in the colon. Interestingly, broad-spectrum antibiotic ablation of gut microbiota attenuated the adverse effects of the parasitic infection on the cognitive function in mice; cognitive deficits and hippocampal pathological changes were transferred from the infected mice to control mice by fecal microbiota transplantation. In addition, the abundance of butyrate-producing bacteria and the production of serum butyrate were decreased in infected mice. Interestingly, dietary supplementation of butyrate ameliorated T. gondii-induced cognitive impairment in mice. Notably, compared to the healthy controls, decreased butyrate production was observed in the serum of human subjects with high levels of anti-T. gondii IgG. Overall, this study demonstrates that gut microbiota is a key regulator of T. gondii-induced cognitive impairment.

Gut microbiota composition is associated with disease severity and host immune responses in COVID-19.

Human gut microbiota play a crucial role in the immune response of the host to respiratory viral infection. However, evidence regarding the association between the gut microbiome, host immune responses, and disease severity in coronavirus disease 2019 (COVID-19) remains insufficient. To better comprehend the interactions between the host and gut microbiota in COVID-19, we conducted 16S rRNA sequencing and characterized the gut microbiome compositions in stool samples from 40 COVID-19 patients and 33 non-pneumonia controls. We assessed several hematological parameters to determine the immune status. We found that the gut microbial composition was significantly changed in COVID-19 patients, which was characterized by increased opportunistic pathogens and decreased commensal bacteria. The frequency of prevalent opportunistic pathogens Enterococcus and Lactobacillus increased, especially in severe patients; yet the abundance of butyrate-producing bacteria, Faecalibacterium, Roseburia, and Anaerostipes, decreased significantly, and Faecalibacterium prausnitzii might help discriminate severe patients from moderate patients and non-pneumonia people. Furthermore, we then obtained a correlation map between the clinical characteristics of COVID-19 and severity-related gut microbiota. We observed a notable correlation between the abundance of Enterococcus faecium and abnormal neutrophil or lymphocyte percentage in all COVID-19 patients. Faecalibacterium was positively correlated with lymphocyte counts, while negatively correlated with neutrophil percentage. These results suggested that the gut microbiome could have a potential function in regulating host immune responses and impacting the severity or consequences of diseases.

Can dietary magnesium sources and buffer change the ruminal microbiota composition and fermentation of lactating dairy cows?

Magnesium oxide (MgO) is one of the most used Mg supplements in livestock. However, to avoid relying upon only one Mg source, it is important to have alternative Mg sources. Therefore, the objective of this study was to evaluate the effects of the interaction of two Mg sources with buffer use on the ruminal microbiota composition, ruminal fermentation, and nutrient digestibility in lactating dairy cows. Twenty lactating Holstein cows were blocked by parity and days in milk into five blocks with four cows each, in a 2 × 2 factorial design. Within blocks, cows were assigned to one of four treatments: 1) MgO; 2) MgO + Na sesquicarbonate (MgO+); 3) calcium-magnesium hydroxide (CaMgOH); 4) CaMgOH + Na sesquicarbonate (CaMgOH+). For 60 d, cows were individually fed a corn silage-based diet, and treatments were top-dressed. Ruminal fluid was collected via an orogastric tube, for analyses of the microbiota composition, volatile fatty acids (VFA), lactate, and ammonia nitrogen (NH3-N). The microbiota composition was analyzed using V4/16S rRNA gene sequencing, and taxonomy was assigned using the Silva database. Statistical analysis was carried out following the procedures of block design analysis, where block and cow were considered random variables. Effects of Mg source, buffer, and the interaction between Mg Source × Buffer were analyzed through orthogonal contrasts. There was no interaction effect of the two factors evaluated. There was a greater concentration of NH3-N, lactate, and butyrate in the ruminal fluid of cows fed with CaMg(OH)2, regardless of the buffer use. The increase in these fermentation intermediates/ end-products can be explained by an increase in abundance of micro-organisms of the genus Prevotella, Lactobacillus, and Butyrivibrio, which are micro-organisms mainly responsible for proteolysis, lactate-production, and butyrate-production in the rumen, respectively. Also, dietary buffer use did not affect the ruminal fermentation metabolites and pH; however, an improvement of the apparent total tract digestibility of dry matter (DM), organic matter (OM), neutral fiber detergent (NDF), and acid fiber detergent (ADF) were found for animals fed with dietary buffer. In summary, there was no interaction effect of buffer use and Mg source, whereas buffer improved total tract apparent digestibility of DM and OM through an increase in NDF and ADF digestibility and CaMg(OH)2 increased ruminal concentration of butyrate and abundance of butyrate-producing bacteria.

Dietary autolysed yeast modulates blood profiles, small intestinal morphology and caecal microbiota of weaning pigs

Yeast products are potential feed additives due to their beneficial effects on gut health. Thus, we verified the potential impacts of autolysed yeast (AY) on growth performance, blood profiles, gut morphology and microbiota in weaning pigs. In total, 72 castrated, commercial, crossbred, weaning pigs were divided into three groups, with each group consisting of eight replicates with three piglets each. The experimental diets were as follows: 1) control diet (0% AY); 2) diet with 1.0% AY; 3) diet with 3.0% AY. For the overall period, using 1.0% AY in the diet seemed to improve the feed conversion ratio (P = 0.09); whereas, other productive performance parameters were not significantly affected by the supplementations. Using 1.0% AY in the diet significantly decreased the blood urea nitrogen and neutrophil/lymphocyte ratio (N/L ratio) but increased the eosinophil count (P < 0.05). Adding AY to the diet did not influence caecal microbial diversity; using 1.0% AY in the diet decreased the abundances of the phylum Actinobacteria, the class Coriobacteriia and the family Coriobacteriaceae (P < 0.05). At the genus level, an AY inclusion level of 1.0% reduced the abundances of Collinsella, Clostridium and Catenibacterium and increased that of Marvinbryantia (P < 0.05). Furthermore, the abundance of butyrate-producing bacteria seemed to be increased by AY supplementation (P = 0.06). Pearson’s correlation coefficient (r) analysis revealed that AY intake was negatively associated with the abundance of pathogens of the genera Dorea (r = −0.84; P = 0.03) and Catenibacterium (r = −0.80; P = 0.04). This indicates that AY intake potentially reduces the population of some pathogenic bacteria at family level. Thus, using an appropriate AY inclusion level (1.0%) seemed to improve the feed use of postweaning pigs and clearly improved their small intestinal morphology, blood profiles and caecal microbiota.

Alterations in intestinal microbiota in ultramarathon runners

To date, only one study has reported changes in the gut microbiome of an ultramarathon runner before and after competing in the race. Herein we aimed to investigate changes in intestinal microbiota in nine ultramarathon runners. Eight of the nine participants ran 96.102 km (up 8062 m, down 6983 km) and one ran 99.12 km (up 8448 m, down 7369 m) within 38–44 h. Intestinal microbiota alterations were examined at three timepoints: before (Pre), after (Post), and 10 days after (Recovery) the race. The α- and β-diversity of intestinal microbiota were unaffected by the race. Six of the nine participants showed the B-type enterotype, while the remaining three showed the P-type enterotype; however, significant difference between enterotypes was not observed in the influence of the ultramarathon on intestinal microbiota. The abundance of mean Faecalibacterium prausnitzii, was significantly decreased from 2.9% (Pre) to 1.6% (Post), as well as other three butyrate producing bacteria. One participant with the largest decrease in F. prausnitzii abundance (− 85.7%) reported sluggishness and shallow sleep from Post to Recovery. Our findings revealed that the abundance of butyrate-producing bacteria is decreased in ultramarathon runners, which consequently decreases butyrate levels in the intestine and affects host immune function.

Pediococcus acidilactici Strain Alleviates Gluten-Induced Food Allergy and Regulates Gut Microbiota in Mice.

Wheat flour, the most important source of food globally, is also one of the most common causative agents of food allergy. Wheat gluten protein, which accounts for 80% of the total wheat protein, is a major determinant of important wheat-related disorders. In this study, the effects of Pediococcus acidilactici XZ31 against gluten-induced allergy were investigated in a mouse model. The oral administration of P. acidilactici XZ31 attenuated clinical and intestinal allergic responses in allergic mice. Further results showed that P. acidilactici XZ31 regulated Th1/Th2 immune balance toward Th1 polarization, which subsequently induced a reduction in gluten-specific IgE production. We also found that P. acidilactici XZ31 modulated gut microbiota homeostasis by balancing the Firmicutes/Bacteroidetes ratio and increasing bacterial diversity and the abundance of butyrate-producing bacteria. Specifically, the abundance of Firmicutes and Erysipelotrichaceae is positively correlated with concentrations of gluten-specific IgE and may act as a fecal biomarker for diagnosis. The evidence for the role of P. acidilactici XZ31 in alleviating gluten-induced allergic responses sheds light on the application of P. acidilactici XZ31 in treating wheat allergy.

The gut fungal and bacterial microbiota in pediatric patients with inflammatory bowel disease introduced to treatment with anti-tumor necrosis factor-\u03b1

Pediatric inflammatory bowel disease (PIBD) is a globally increasing chronic inflammatory disease associated with an imbalanced intestinal microbiota and treated with several treatment options, including anti-tumor necrosis factor alpha (TNF-α), such as infliximab (IFX). Up to half of the patients do not respond to the drug and there are no methods for response prediction. Our aim was to predict IFX response from the gut microbiota composition since this is largely unexplored in PIBD. The gut microbiota of 30 PIBD patients receiving IFX was studied by MiSeq sequencing targeting 16S and ITS region from fecal samples collected before IFX and two and six weeks after the start of treatment. The response to IFX induction was determined by fecal calprotectin value < 100 µg/g at week six. The bacterial microbiota differed significantly between response groups, with higher relative abundance of butyrate-producing bacteria in responders compared to non-responders at baseline, validated by high predictive power (area under curve = 0.892) for baseline Ruminococcus and calprotectin. Additionally, non-responders had higher abundance of Candida, while responders had higher abundance of Saccharomyces at the end of the study. The gut microbiota composition in PIBD patients could predict response to IFX treatment in the future.

Gut Microbiota, Glucose, Lipid, and Water-Electrolyte Metabolism in Children With Nonalcoholic Fatty Liver Disease.

There is evidence that nonalcoholic fatty liver disease (NAFLD) is affected by gut microbiota, glucose, and lipid. However, the function of water-electrolyte metabolism remains undefined in children with NAFLD. Therefore, the aim of this case-control study was to better understand these interactions. The sample consisted of 75 children, aged between 7 and 16, of whom 25 had nonalcoholic fatty liver (NAFL), 25 had nonalcoholic steatohepatitis (NASH), and 25 were obese and without NAFLD. These groups were matched by age, sex, and body mass index. Data were collected between June, 2019 and December, 2019 at the Hunan Children’s Hospital, in China. Microbiome composition in fecal samples was assessed using 16S ribosomal RNA amplicon sequencing. In the clinical indices, 12 glucose and lipid metabolism indices were included, and six water-electrolyte metabolism indices were included. The results indicated that microbiomes of NAFLD children had lower alpha diversity but higher beta diversity index than the other two groups. Specifically, anti-inflammatory and probiotics abundance (e.g., Faecalibacterium, Akkermansia, and Bifidobacterium_adolescentis) was significantly decreased in NAFLD, whereas the abundance of harmful bacteria (e.g., Staphylococcaceae) was increased. Moreover, the abundance of butyrate-producing bacteria (e.g., Faecalibacterium, Roseburia_inulinivorans, Roseburia_intestinalis, and Coprococcus_comes) was significantly decreased in NASH. The abundance of these bacteria were associated with glucose, lipid, and water-electrolyte metabolism (e.g., glucose, triglyceride, cholesterol, inorganic salt, total body water, etc.), implying that the NAFLD and its severity were associated with glucose, lipid, and water-electrolyte metabolism dysbiosis. Therefore, these findings suggest that the gut microbiome, especially butyrate-producing bacteria, play an important role in the development of NAFLD in children.

Glycerol Monolaurate Ameliorated Intestinal Barrier and Immunity in Broilers by Regulating Intestinal Inflammation, Antioxidant Balance, and Intestinal Microbiota.

This study was conducted to investigate the impact of glycerol monolaurate (GML) on performance, immunity, intestinal barrier, and cecal microbiota in broiler chicks. A total of 360 one-day-old broilers (Arbor Acres) with an average weight of 45.7 g were randomly allocated to five dietary groups as follows: basal diet and basal diets complemented with 300, 600, 900, or 1200 mg/kg GML. Samples were collected at 7 and 14 days of age. Results revealed that feed intake increased (P < 0.05) after 900 and 1200 mg/kg GML were administered during the entire 14-day experiment period. Dietary GML decreased (P < 0.05) crypt depth and increased the villus height-to-crypt depth ratio of the jejunum. In the serum and jejunum, supplementation with more than 600 mg/kg GML reduced (P < 0.05) interleukin-1β, tumor necrosis factor-α, and malondialdehyde levels and increased (P < 0.05) the levels of immunoglobulin G, jejunal mucin 2, total antioxidant capacity, and total superoxide dismutase. GML down-regulate (P < 0.05) jejunal interleukin-1β and interferon-γ expression and increased (P < 0.05) the mRNA level of zonula occludens 1 and occludin. A reduced (P < 0.05) expression of toll-like receptor 4 and nuclear factor kappa-B was shown in GML-treated groups. In addition, GML modulated the composition of the cecal microbiota of the broilers, improved (P < 0.05) microbial diversity, and increased (P < 0.05) the abundance of butyrate-producing bacteria. Spearman’s correlation analysis revealed that the genera Barnesiella, Coprobacter, Lachnospiraceae, Faecalibacterium, Bacteroides, Odoriacter, and Parabacteroides were related to inflammation and intestinal integrity. In conclusion, GML ameliorated intestinal morphology and barrier function in broiler chicks probably by regulating intestinal immune and antioxidant balance, as well as intestinal microbiota.

Rumen microbiota and its relation to fermentation in lactose-fed calves

In our previous studies, we revealed the effect of lactose inclusion in calf starters on the growth performance and gut development of calves. We conducted the present study as a follow-up study to identify the shift in rumen microbiota and its relation to rumen fermentation when calves are fed a lactose-containing starter. Thirty Holstein bull calves were divided into 2 calf starter treatment groups: texturized calf starter (i.e., control; n = 15) or calf starter in which starch was replaced with lactose at 10% (i.e., LAC10; n = 15) on a dry matter basis. All calves were fed their respective treatment calf starter ad libitum from d 7, and kleingrass hay from d 35. Rumen digesta were collected on d 80 (i.e., 3 wk after weaning) and used to analyze rumen microbiota and fermentation products. There was no apparent effect of lactose feeding on the α-diversity and overall composition of rumen microbiota. Amplicon sequencing and real-time PCR quantification of the 16S rRNA gene confirmed that the abundance of butyrate-producing bacteria (i.e., Butyrivibrio group and Megasphaera elsdenii) did not differ between the control and LAC10 groups. Conversely, the relative abundance of Mitsuokella spp., which produce lactate, succinate, and acetate, was significantly higher in the rumen of calves that were fed lactose, whereas the lactate concentration did not differ between the control and LAC10 groups. These findings suggest that the lactate production can be elevated by an increase of Mitsuokella spp. and then converted into butyrate, not propionate, since the proportion of propionate was lower in lactose-fed calves. In addition, we observed a higher abundance of Coriobacteriaceae and Pseudoramibacter-Eubacterium in the LAC10 group. Both these bacterial taxa include acetate-producing bacteria, and a positive correlation between the acetate-to-propionate ratio and the abundance of Pseudoramibacter-Eubacterium was observed. Therefore, the higher abundance of Coriobacteriaceae, Mitsuokella spp., and Pseudoramibacter-Eubacterium in the rumen of lactose-fed calves partially explains the increase in the proportion of rumen acetate that was observed in our previous study.

Pregnant women who develop preeclampsia have lower abundance of the butyrate-producer Coprococcus in their gut microbiota.

Preeclampsia is a pregnancy-specific disorder characterized by hypertension and dysfunction of several organs, that is associated with maternal and fetal complications. The human gut microbiota is related to health and disease including hypertension. Alterations in gut microbiota composition can change the short-chain fatty acid profile released by the bacteria and contribute to hypertension and metabolic syndrome. It is unclear if the composition of the gut microbiota is altered in women who develop late-onset preeclampsia. In this study, we investigated the composition of the gut microbiota at 28weeks gestation in women who developed late-onset (>34weeks gestation) preeclampsia (DPE) by 16S rRNA gene amplicon sequencing of fecal samples obtained from 213 pregnant women in the SPRING cohort (Study of Probiotics IN Gestational diabetes). Quantitative real-time PCR was used to assess the density of butyrate-producing genes. Gut microbiota composition was compared between women with and without DPE. The abundance of the butyrate-producing Coprococcus genus significantly decreased in DPE. Abundance of Coprococcus is significantly and positively correlated with the abundance of genes encoding the terminal step in bacterial butyrate formation (but and buk). Women with DPE also had significantly reduced levels of serum butyrate prior to the development of symptoms than controls. This study suggests that a reduction in the abundance of butyrate-producing bacteria, and Coprococcus spp. in particular, may contribute to an increased risk of developing preeclampsia in pregnant women.

Clinical Significance of the Correlation between Changes in the Major Intestinal Bacteria Species and COVID-19 Severity.

Coronavirus disease 2019 (COVID-19) is a highly contagious infectious disease. Similar to H7N9 infection, pneumonia and cytokine storm are typical clinical manifestations of COVID-19. Our previous studies found that H7N9 patients had intestinal dysbiosis. However, the relationship between the gut microbiome and COVID-19 has not been determined. This study recruited a cohort of 57 patients with either general (n = 20), severe (n = 19), or critical (n = 18) disease. The objective of this study was to investigate changes in the abundance of ten predominant intestinal bacterial groups in COVID-19 patients using quantitative polymerase chain reaction (q-PCR), and to establish a correlation between these bacterial groups and clinical indicators of pneumonia in these patients. The results indicated that dysbiosis occurred in COVID-19 patients and changes in the gut microbial community were associated with disease severity and hematological parameters. The abundance of butyrate-producing bacteria, such as Faecalibacterium prausnitzii, Clostridium butyricum, Clostridium leptum, and Eubacterium rectale, decreased significantly, and this shift in bacterial community may help discriminate critical patients from general and severe patients. Moreover, the number of common opportunistic pathogens Enterococcus (Ec) and Enterobacteriaceae (E) increased, especially in critically ill patients with poor prognosis. The results suggest that these bacterial groups can serve as diagnostic biomarkers for COVID-19, and that the Ec/E ratio can be used to predict death in critically ill patients.

Implication of the gut microbiome composition of type 2 diabetic patients from northern China

Emerging evidence has suggested the association of the gut microbiome with some human diseases, including type 2 diabetes (T2D). In this study, we analyzed the gut microbiota from a cohort of healthy and diabetic Chinese individuals from Northern China. Pyrosequencing of the V4V5 region of 16S rRNA genes revealed a significant decrease in the gut microbiota diversity of diabetic patients as compared to healthy individuals. Butyrate-producing bacteria such as Bifidobacterium and Akkermansia were significantly decreased in diabetic patients. Furthermore, the abundance of Dorea was significantly increased in T2D individuals and negatively correlated with the abundance of butyrate-producing bacteria. The increase of Dorea could play a role in the development of T2D and has been previously overlooked. Importantly, functional analysis of the gut microbiome revealed for the first time that increased levels of butyrate production via transferases and the degradation of several amino acids due to gut microbial metabolism have strong correlations with T2D in Northern China. Moreover, the potential of gut microbiota-based classifiers to identify individuals with a high risk for T2D has been demonstrated in this study. Taken together, our findings have revealed a previously unappreciated association of the gut microbiome with T2D and have also suggested that changes in gut microbiota may be used to identify individuals at high risk for T2D.

Effect of Wheat Bran on Fecal Butyrate-Producing Bacteria and Wheat Bran Combined with Barley on Bacteroides Abundance in Japanese Healthy Adults.

Wheat bran (WB) is rich in insoluble arabinoxylan, while BARLEYmax (BM) is a barley line that is rich in fructan, resistant starch, and β-glucan. In the present study, we investigated which of these two fiber sources would produce more favorable changes in the fecal variables of healthy subjects. Sixty healthy subjects were randomly divided into four groups (n = 15 per group) and fed twice daily for 4 weeks with baked cereal bars containing neither WB nor BM (WB−BM−), WB without BM (WB+BM−), BM without WB (WB−BM+), or WB and BM (WB+BM+). At baseline and after 4 weeks, the fecal microbiota composition and the concentrations of short-chain fatty acids were measured. A significant interactive effect of WB and BM on the abundance of genus Bacteroides was observed at week 4. The abundance of butyrate-producing bacteria and the fecal concentration of n-butyrate were significantly higher in the WB+ groups than in the WB− groups. In conclusion, WB was associated with elevated fecal concentrations of short-chain fatty acids including butyrate owing to an increase in the abundance of butyrate-producing bacteria. Additionally, the combination of WB and BM was associated with an increase in the abundance of genus Bacteroides. Therefore, both WB alone and WB combined with BM favorably influenced the fecal variables of healthy subjects.

Anemia in infancy is associated with alterations in systemic metabolism and microbial structure and function in a sex-specific manner: an observational study

Anemia is a term that describes low hemoglobin concentrations and can result from micronutrient deficiencies, infection, or low birth weight. Early-life anemia, particularly iron-deficiency anemia (IDA) is associated with several negative metabolic, developmental, and cognitive outcomes, some of which persist into adulthood. The aim of this study was to investigate alterations in systemic metabolism and fecal microbial diversity and functionality associated with anemia and IDA in male and female infants from Iquitos, Peru. Cross-sectional stool and serum samples were collected from 95 infants (53 boys and 42 girls) at 12 mo of age. The fecal microbiome was assessed by using 16S ribosomal RNA gene sequencing, and the fecal and serum metabolomes were quantified using 1H-nuclear magnetic resonance. The prevalence of anemia was 64%, with a greater proportion of anemia in male infants attributed to iron deficiency. Metabolically, anemia was associated with decreased concentrations of tricarboxylic acid cycle metabolites in both sexes (males: succinate, P=0.031; females: fumarate, P=0.028). In addition, anemic male infants exhibited significantly lower serum concentrations of several amino acids compared with nonanemic male infants. Although no specific structural or functional differences in the microbiota were observed with anemia in general, likely due the heterogeneity of its etiology, IDA affected the microbiome both structurally and functionally. Specifically, the abundance of butyrate-producing bacteria was lower in IDA subjects of both sexes than in nonanemic, non-iron-deficient subjects of the same sex (females: Butyricicoccus, P=0.041; males: Coprococcus, P=0.010; Roseburia, P=0.027). IDA male infants had higher concentrations of 4-hydroxyphenyllactate (P<0.001) and putrescine (P=0.042) than those without IDA, whereas IDA female infants exhibited higher concentrations of leucine (P=0.011) and valine (P=0.003). Sexually dimorphic differences associated with anemia and IDA are suggestive of greater mitochondrial dysfunction and oxidative stress in male infants compared with female infants, and alterations in microbial structure and function may further contribute. Differences in metabolic pathways associated with anemia and IDA in each sex point to potential mechanisms for the associated lasting cognitive deficits. This trial is registered at clinicaltrials.gov as NCT03377777.

71. Altered composition of the gut microbiota in women who develop hypertensive disorders of pregnancy

Introduction Metabolites released by the gut microbiota affect host physiology. Hypertension is associated with altered composition of the gut microbiota. In early pregnancy, the abundance of bacteria producing the short-chain fatty acid butyrate, is negatively correlated with blood pressure in the mother. Butyrate may affect blood pressure through affecting GPR41 and 43 signalling. It is unclear if gut microbiota composition is altered in women who develop hypertensive disorders of pregnancy (HDP). Objective To compare the composition of the gut microbiota at 28 weeks gestation between women who do and do not develop HDP later in pregnancy. Methods Gut microbiota composition was assessed by 16S rRNA sequencing in faecal samples obtained from participants in the Study of Probiotics IN gestational diabetes (SPRING) RCT at 28 weeks gestation. In SPRING, women were randomised to a probiotics or placebo intervention from 16 weeks gestation. Gut microbiota composition was assessed using the QIIME and Calypso software suites. The composition was compared between women with future HDP (N = 32) and those who remained normotensive (N = 182). Results Rates of HDP and overall gut microbiota composition were similar between women randomised to probiotics (7.1%, N = 15) and placebo (8.0%, N = 17; P = 0.85) and the treatment groups were therefore pooled. At 28 weeks gestation, the women with future HDP already had significantly higher systolic and diastolic blood pressures than those who remained normotensive. Women with future HDP had higher abundance of Collinsella aerofasciens, Ruminococcus gnavus, Blautia producta and Bifidobacterium longum. They had lower abundance of Faecalibacterium prausnitzii, Coprococcus eutactus and Roseburia faecis, which are all known butyrate producers. Discussion The gut microbiota of women with future HDP has lower abundance of butyrate-producing bacteria at 28 weeks gestation prior to the development of overt hypertension. This may suggest that lower abundance of short-chain fatty acid producers predisposes to the development of HDP.

Structural shift of gut microbiota during chemo-preventive effects of epigallocatechin gallate on colorectal carcinogenesis in mice.

AIMTo investigate the effect of epigallocatechin gallate (EGCG) on structural changes of gut microbiota in colorectal carcinogenesis.METHODSAn azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colitis mouse model was established. Forty-two female FVB/N mice were randomly divided into the following three groups: group 1 (10 mice, negative control) was treated with vehicle, group 2 (16 mice, positive control) was treated with AOM plus vehicle, and group 3 (16 mice, EG) was treated with AOM plus EGCG. For aberrant crypt foci (ACF) evaluation, the colons were rapidly took out after sacrifice, rinsed with saline, opened longitudinally, laid flat on a polystyrene board, and fixed with 10% buffered formaldehyde solution before being stained with 0.2% methylene blue in saline. For tumor evaluation, the colon was macroscopically inspected and photographed, then the total number of tumors was enumerated and tumor size measured. For histological examination, the fixed tissues were paraffin-embedded and sectioned at 5 mm thickness. Microbial genomic DNA was extracted from fecal and intestinal content samples using a commercial kit. The V4 hypervariable regions of 16S rRNA were PCR-amplified with the barcoded fusion primers. Using the best hit classification option, the sequences from each sample were aligned to the RDP 16S rRNA training set to classify the taxonomic abundance in QIIME. Statistical analyses were then performed.RESULTSTreatment of mice with 1% EGCG caused a significant decrease in the mean number of ACF per mouse, when compared with the model mice treated with AOM/DSS (5.38 ± 4.24 vs 13.13 ± 3.02, P < 0.01). Compared with the positive control group, 1% EGCG treatment dependently decreased tumor load per mouse by 85% (33.96 ± 6.10 vs 2.96 ± 2.86, respectively, P < 0.01). All revealed that EGCG could inhibit colon carcinogenesis by decreasing the number of precancerous lesions as well as solid tumors, with reduced tumor load and delayed histological progression of CRC. During the cancerization, the diversity of gut microbiota increased, potential carcinogenic bacteria such as Bacteroides were enriched, and the abundance of butyrate-producing bacteria (Clostridiaceae, Ruminococcus, etc.) decreased continuously. In contrast, the structure of gut microbiota was relatively stable during the intervention of EGCG on colon carcinogenesis. Enrichment of probiotics (Bifidobacterium, Lactobacillu, etc.) might be a potential mechanism for EGCG’s effects on tumor suppression. Via bioinformatics analysis, principal coordinate analysis and cluster analysis of the tumor formation process, we found that the diversity of gut microbiota increased in the tumor model group while that in the EGCG interfered group (EG) remained relatively stable.CONCLUSIONGut microbiota imbalance might be a potential mechanism for the prevention of malignant transformation by EGCG, which is significant for diagnosis, treatment, prognosis evaluation, and prevention of colorectal cancer.

Microbe-based approaches for the treatment of diabetes

The adult human intestinal microbiota comprises 10–10 microorganisms, and the gut microbiome, in other words, the aggregate genome of all microorganisms, is around 100-times larger than the human genome. Intestinal dysbiosis is defined as a state of imbalance of the gut microbial ecosystem, including the overgrowth of some organisms and the loss of others. Dysbiosis has been implicated in a series of major chronic diseases such as Type 1 diabetes and obesity and Type 2 diabetes [1,2]. These observations raise the issue of whether measures aimed at restoring the balance of the microbiota and correcting the dysbiosis could be applied for the prevention and/or treatment of these metabolic disorders. In the context of Type 1 diabetes it has been reported, based on prospective studies, that autoantibody-positive children en route to clinical disease are characterized by a decreased bacterial and functional diversity and a reduced community stability when compared with autoantibody-negative controls matched for gender, date of birth and HLA genotype [3,4]. Bacteroidetes seems to be the dominant phylum among autoantibodypositive children and at the genus level an increased abundance of Bacteroides and Clostridium was observed [3,5], although not consistently so [6]. In addition, the autoantibody-positive children, who later progressed to clinical Type 1 diabetes or carried a high risk of progression, were characterized by a decreased abundance of butyrate-producing bacteria [5,7]. A recent prospective study with monthly stool samples starting from birth showed that the difference in microbial diversity between seroconverters and controls emerged after seroconversion to autoantibody positivity [4] indicating that the altered microbiota may be involved in the progression from β-cell autoimmunity to overt diabetes rather than in the initiation of β-cell autoimmunity. A very recent study comparing the intestinal microbiota in children with HLA-conferred diabetes susceptibility derived from six centers taking part in the international TEDDY study showed clear significant differences in the bacterial diversity and in the abundance of several bacterial

Severity of atopic disease inversely correlates with intestinal microbiota diversity and butyrate-producing bacteria.

The reports on atopic diseases and microbiota in early childhood remain contradictory, and both decreased and increased microbiota diversity have been associated with atopic eczema. In this study, the intestinal microbiota signatures associated with the severity of eczema in 6-month-old infants were characterized. Further, the changes in intestinal microbiota composition related to the improvement of this disease 3months later were assessed. The severity of eczema correlated inversely with microbiota diversity (r=-0.54, P=0.002) and with the abundance of butyrate-producing bacteria (r=-0.52, P=0.005). During the 3-month follow-up, microbiota diversity increased (P<0.001) and scoring atopic dermatitis values decreased (P<0.001) in all infants. This decrease coincided with the increase in bacteria related to butyrate-producing Coprococcus eutactus (r=-0.59, P=0.02). In conclusion, the high diversity of microbiota and high abundance of butyrate-producing bacteria were associated with milder eczema, thus suggesting they have a role in alleviating symptoms of atopic eczema.

Scouring weaner pigs have a lower abundance of butyrate-producing bacteria

Scouring weaner pigs have a lower abundance of butyrate-producing bacteria