Abundance of Probiotics and Butyrate-Production Microbiome Manages Constipation via Short-Chain Fatty Acids Production and Hormones Secretion

Gut Dysbiosis Has the Potential to Reduce the Sexual Attractiveness of Mouse Female

Increasing evidence has shown that the gut microbiome has significant effects on mate preferences of insects; however, whether gut microbiota composition affects sexual attractiveness and mate preference in mammals remains largely unknown. Here, we showed that antibiotic treatment significantly restructured the gut microbiota composition of both mouse males and females. Males, regardless of antibiotic treatment, exhibited a higher propensity to interact with the control females than the antibiotic-treated females. The data clearly showed that gut microbiota dysbiosis reduced the sexual attractiveness of females to males, implying that commensal gut microbiota influences female attractiveness to males. The reduced sexual attractiveness of the antibiotic-treated females may be beneficial to discriminating males by avoiding disorders of immunity and sociability in offspring that acquire maternal gut microbiota via vertical transmission. We suggest further work should be oriented to increase our understanding of the interactions between gut microbiota dysbiosis, sexual selection, and mate choice of wild animals at the population level.

Parkinson's Disease Is Associated with Impaired Gut-Blood Barrier for Short-Chain Fatty Acids

BACKGROUND

Short-chain fatty acids (SCFAs) produced by gut microbiota are reduced in feces but paradoxically increased in plasma of patients with Parkinson's disease (PD), which may stem from intestinal wall leakage. Gut function should be taken into consideration when conducting microbial-metabolite research.

OBJECTIVE

The objective was to investigate synchronous changes of SCFAs in feces and plasma of patients with PD, taking constipation as a confounder to better disentangle the SCFA metabolism exclusively associated with PD.

METHODS

The concentrations of fecal and plasma SCFAs in 33 healthy control subjects and 95 patients with PD were measured using liquid and gas chromatography mass spectrometry, respectively. Patients with PD were divided into patients with PD without constipation (n = 35) and patients with PD with constipation (n = 60). Gut-blood barrier (GBB) permeability was assessed by plasma/fecal ratio of SCFA concentrations and fecal α1-antitrypsin concentration.

RESULTS

Patients with PD displayed decreased concentrations of fecal acetic, propionic, and butyric acid and increased concentrations of plasma acetic and propionic acid. Fecal acetic, isobutyric, and isovaleric acid were lower and plasma acetic and propionic acid were higher in patients with PD with constipation than in patients with PD without constipation. Constipation aggravated GBB permeability in patients with PD. Combined fecal and plasma SCFAs could discriminate patients with PD from healthy control subjects. Fecal SCFAs, except propionic acid, were negatively correlated with disease severity, while plasma acetic, propionic, and valeric acid showed a positive correlation.

CONCLUSIONS

Our study showed alterations of fecal and plasma SCFAs in patients with PD that were associated with an impaired GBB and might be aggravated by constipation. © 2022 International Parkinson and Movement Disorder Society.

Effects of Different Ionic Polysaccharides in Cooked Lean Pork Batters on Intestinal Health in Mice

The effects of cooked lean pork batters with three ionic types of polysaccharides (anionic xanthan-gum/sodium-alginate, neutral curdlan-gum/konjac-gum and cationic chitosan) on the intestinal health of mice were investigated in this study. The results showed that the zeta potential in the sodium-alginate group (−31.35 mV) was higher (p < 0.05) than that in the chitosan group (−26.00 mV), thus promoting the protein hydrolysis in the anionic group because of electrostatic repulsion. The content of total free amino acids in the small intestine in the xanthan-gum and sodium-alginate groups (2754.68 μg and 2733.72 μg, respectively) were higher (p < 0.05) than that in the chitosan group (1949.78 μg), which could decrease the amount of undigested protein entering the colon. The two anionic groups could also increase the abundance of Lactobacillus and the balance of Faecalibaculum and Alistipes in the colon. The content of proinflammatory factor IL−6 of colon tissues in the sodium-alginate group (1.02 ng/mL) was lower (p < 0.05) than that in chitosan, curdlan-gum and konjac-gum groups (1.29, 1.31 and 1.31 ng/mL, respectively). The result of haematoxylin-eosin staining of the colon also revealed that sodium alginate was beneficial for colonic health. The two neutral groups increased the content of faecal short-chain fatty acids in mice. These results demonstrated that anionic polysaccharides have potential for developing functional low-fat meat products.

Bifidobacterium longum relieves constipation by regulating the intestinal barrier of mice

Constipation is a major health concern worldwide, requiring effective and safe treatment options. This study mainly focused on three species and nine strains of bifidobacteria from different sources to study their abilities to relieve constipation induced by loperamide in BALB/C mice. By monitoring constipation-related indicators, it was found that only Bifidobacterium longum (B. longum) relieved constipation, which indicated that bifidobacteria had inter-species differences in relieving constipation. Furthermore, through the detection of biological, chemical, mechanical, and immune barriers in mice, it was discovered that B. longum upregulates the relative abundance of 22 genera that were positively related to faecal water content, small intestinal propulsion rate, acetate, propionate, and intestinal mechanical barrier and negatively correlated with inflammatory factors, AQP8 and the time of first black stool and downregulates the relative abundance of Akkermansia. Furthermore, it increased the level of acetate in faeces and reduced the expression of AQP8 in the colon. This enhances intestinal motility and improves water and electrolyte metabolism. Meanwhile, it inhibited inflammation and prevented loperamide-induced intestinal barrier damage in constipated mice by upregulating occludin and downregulating IL-1β and TNF-α. In summary, B. longum relieved constipation by regulating the intestinal barrier in constipated mice.

Effects of Maren Pills on the Intestinal Microflora and Short-Chain Fatty Acid Profile in Drug-Induced Slow Transit Constipation Model Rats

Background: Slow transit constipation (STC) is becoming a common and frequently occurring disease in today’s society, and it is necessary to explore the safe and effective treatment of STC.

Method: Our study aimed to investigate whether the laxative effect of Maren pills (MRW) is associated with the regulation of intestinal microflora and intestinal metabolism in the colon. Loperamide hydrochloride-induced STC rats received MRW intragastrically for two consecutive weeks to evaluate the laxative effect of MRW involving the regulation of intestinal microflora, intestinal metabolism, and 5-HT signaling pathway. Intestinal microflora was detected by 16s rDNA sequencing, intestinal metabolism of short-chain fatty acids (SCFAs) was detected by HPLC, and the 5-HT signaling pathway was detected by WB, ELISA, immunofluorescence, and immunohistochemical analysis.

Results: Our results revealed that the treatments with MRW increased not only the body weight, 24-h fecal number, 24-h wet fecal weight, 24-h dry fecal weight, fecal water content, and the intestinal propulsion rate but also the colonic goblet cell number, colonic Muc-2 protein expression, and colonic mucus layer thickness in the STC model rats. Moreover, MRW activated the 5-HT pathway by increasing the levels of 5-HT, 5-HIAA, 5-HT4R, CFTR, cAMP, and PKA in the colon tissue of STC rats. The 16S rDNA sequencing results showed that MRW improved the colonic microflora structure in colonic contents of STC rats, mainly by increasing Lactobacillus and decreasing Prevotella. Finally, we found that MRW regulated the SCFA metabolism in the colonic contents of the STC rats, mainly by increasing the contents of acetic acid, propionic acid, and butyric acid; the relative abundance of Lactobacillus was positively correlated with either contents of acetic acid, propionic acid, and butyric acid, and the relative abundance of Clostridium was negatively correlated.

Conclusion: Our study further showed that MRW could improve constipation in STC rats, and the mechanism may be by regulating the intestinal microflora structure and improving the metabolism of SCFAs.

Higher total faecal short-chain fatty acid concentrations correlate with increasing proportions of butyrate and decreasing proportions of branched-chain fatty acids across multiple human studies

Metabolites produced by microbial fermentation in the human intestine, especially short-chain fatty acids (SCFAs), are known to play important roles in colonic and systemic health. Our aim here was to advance our understanding of how and why their concentrations and proportions vary between individuals. We have analysed faecal concentrations of microbial fermentation acids from 10 human volunteer studies, involving 163 subjects, conducted at the Rowett Institute, Aberdeen, UK over a 7-year period. In baseline samples, the % butyrate was significantly higher, whilst % iso-butyrate and % iso-valerate were significantly lower, with increasing total SCFA concentration. The decreasing proportions of iso-butyrate and iso-valerate, derived from amino acid fermentation, suggest that fibre intake was mainly responsible for increased SCFA concentrations. We propose that the increase in % butyrate among faecal SCFA is largely driven by a decrease in colonic pH resulting from higher SCFA concentrations. Consistent with this, both total SCFA and % butyrate increased significantly with decreasing pH across five studies for which faecal pH measurements were available. Colonic pH influences butyrate production through altering the stoichiometry of butyrate formation by butyrate-producing species, resulting in increased acetate uptake and butyrate formation, and facilitating increased relative abundance of butyrate-producing species (notably Roseburia and Eubacterium rectale).

The Anti-Constipation Effects of Raffino-Oligosaccharide on Gut Function in Mice Using Neurotransmitter Analyses, 16S rRNA Sequencing and Targeted Screening

Raffino-oligosaccharide (ROS), the smallest oligosaccharide of the raffinose family, is a novel food ingredient. However, the anti-constipation effects of ROS remain obscure. This study investigates the anti-constipation effects of ROS based on the loperamide-induced mice model and reveals the underlying mechanism using constipation parameters, neurotransmitter level, 16S rRNA sequencing, and the targeted screening strategy. The prevention effects were firstly investigated by the gastro-intestinal transit rate experiment (50 mice) and defecation status experiment (50 mice), which were divided into five groups (n = 10/group): blank, model, and low-, medium- and high-dose ROS. Furthermore, the slow-transit constipation experiment (blank, model, and high-dose ROS, n = 10/group) was conducted to illustrate the underlying mechanism. The results showed that ROS aided in preventing the occurrence of constipation by improving the gastro-intestinal transit rate and the defecation frequency in mice, and ROS significantly reduced the serum levels of vasoactive intestinal peptide (VIP). In addition, ROS regulated the diversity and structure of intestinal flora. Among them, one specific family and six specific genera were significantly regulated in constipated mice. The targeted screening revealed that 29 targets related to the anti-constipation effects of ROS, indicating ROS may play a role by regulating multiple targets. Furthermore, the network pharmacology analysis showed that Akt1, Stat3, Mapk8, Hsp90aa1, Cat, Alb, Icam1, Sod2, and Gsk3b can be regarded as the core anti-constipation targets. In conclusion, ROS could effectively relieve constipation, possibly by inhibiting the level of neurotransmitters and regulating the gut flora in mice. This study also provides a novel network pharmacology-based targeted screening strategy to reveal the anti-constipation effects of ROS.

Habitual Dietary Fiber Intake, Fecal Microbiota, and Hemoglobin A1c Level in Chinese Patients with Type 2 Diabetes

High-fiber diet interventions have been proven to be beneficial for gut microbiota and glycemic control in diabetes patients. However, the effect of a low level of fiber in habitual diets remains unclear. This study aims to examine the associations of habitual dietary fiber intake with gut microbiome profiles among Chinese diabetes patients and identify differential taxa that mediated associations of dietary fiber with HbA1c level. Two cross-sectional studies and one longitudinal study were designed based on two follow-up surveys in a randomized trial conducted during 2015−2017. The study included 356 and 310 participants in the first and second follow-ups, respectively, with 293 participants in common in both surveys. Dietary fiber intake was calculated based on a 3-day 24-h diet recall at each survey and was classified into a lower or a higher group according to the levels taken based on the two surveys using 7.2 g/day as a cut-off value. HbA1c was assayed to assess glycemic status using a cut-off point of 7.0% and 8.0%. Microbiome was profiled by 16S rRNA sequencing. A high habitual dietary fiber intake was associated with a decrease in α-diversity in both the cross-sectional and longitudinal analyses. At the first follow−up, phylum Firmicutes and Fusobacteria were negatively associated with a higher dietary fiber intake (p < 0.05, Q < 0.15); at the second follow-up, genus Adlercreutzia, Prevotella, Ruminococcus, and Desulfovibrio were less abundant in patients taking higher dietary fiber (p < 0.05, Q < 0.15); genus Desulfovibrio and Ruminococcaceae (Unknown), two identified differential taxa by HbA1c level, were negatively associated with dietary fiber intake in both the cross-sectional and longitudinal analyses, and mediated the dietary fiber-HbA1c associations among patients taking dietary fiber ≥ 7.2 g/day (mediation effect β [95%CI]: −0.019 [−0.043, −0.003], p = 0.018 and −0.019 [−0.046, −0.003], p = 0.016). Our results suggest that habitual dietary fiber intake has a beneficial effect on gut microbiota in Chinese diabetes patients. Further studies are needed to confirm our results.

Effect of Lotus Seed Resistant Starch on Lactic Acid Conversion to Butyric Acid Fermented by Rat Fecal Microbiota

The aim was to investigate the effect of lotus seed resistant starch (LRS) on lactic acid (LA) conversion to butyric acid (BA) fermented by rat fecal microbiota to construct an acetyl CoA pathway. According to growth curves, the microbiota compositions at 10 and 36 h were further analyzed. The microbiota in the LRS group had higher richness and diversity compared to glucose (GLU) and high amylose maize starch (HAMS). Moreover, LRS and isotope LA promoted the growth of Lactobacillus and Bifidobacterium, promoted BA production, and inhibited the growth of Escherichia-Shigella. The BUT pathway played a dominant role in three groups. At 10 h, Escherichia-Shigella and Bifidobacterium showed a negative correlation with BUT and a positive correlation with BUK, whereas Escherichia-Shigella, Allobaculum, Bifidobacterium, and Ralstonia showed a positive correlation with BUT and BUK at 36 h. [3-¹³C] LA was converted to [4-¹³C] BA by the isotope labeling technique. Finally, LRS promoted LA conversion to BA mainly by the BUT pathway in intestinal microbiota, especially including Allobaculum, Bifidobacterium, and Ralstonia.

A randomised, double-blind, placebo-controlled trial of Bifidobacterium bifidum CCFM16 for manipulation of the gut microbiota and relief from chronic constipation

A variety of opinions exist on the potential of probiotics to provide relief from chronic constipation with much focus being placed on their mechanism of action and causes of heterogeneity in the results of different studies. We aimed to determine the efficacy and safety of ingesting Bifidobacterium bifidum (B. bifidum) CCFM16 for 28 days to relieve constipation and to understand the mechanism of action. Using Rome IV criterion, 53 and 50 participants diagnosed with chronic constipation were included in the probiotic group and placebo group, respectively. Spontaneous bowel movements (SBMs) per week, stool consistency (Bristol Stool Form Scale [BSFS]), the proportion of SBM responders, patient assessment of constipation symptoms (PAC-SYM), and quality of life (PAC-QoL) were evaluated. The gut microbiota, short-chain fatty acids (SCFAs) and other indicators were also assessed. B. bifidum CCFM16 treatment improved the stool consistency and increased the proportion of SBM responders, but the differences in PAC-SYM and PAC-QoL were statistically insignificant between the groups. Analysis of the SCFAs and microbiome revealed that CCFM16 significantly increased the acetic acid and butyric acid concentrations and enhanced the Firmicutes/Bacteroidetes ratio. Levels of Clostridia were particularly increased and were associated with the increase in butyric acid. In addition, we found the other side of Clostridia; several taxa in the order Clostridiales were observed to prevent CCFM16 from proper functioning in the pre-treatment microbiome. In conclusion, CCFM16 can potentially and efficaciously relieve chronic constipation in Chinese adults by regulating the gut microbiota and SCFA metabolism. The two sides of Clostridia illustrate its importance in microbial therapy for constipation.

Integrated Analysis of the Cecal Microbiome and Plasma Metabolomics to Explore NaoMaiTong and Its Potential Role in Changing the Intestinal Flora and Their Metabolites in Ischemic Stroke

Ischemic stroke (IS), as a leading cause of disability worldwide, affects intestinal bacterial communities and their metabolites, while recent discoveries have highlighted the importance of the intestinal microflora in the development of IS. Systematic investigations of complex intestinal bacterial communities and their metabolites during ischemic brain injury contribute to elucidate the promising therapeutic targets for IS. However, the associations between intestinal microbiota and related circulating metabolic processes in IS remained unclear. Hence, to identify the changed microflora and their metabolites in IS of NaoMaiTong (NMT), an effective clinical medication, we established the middle cerebral artery occlusion/reperfusion (MCAO/R) model using conventionalized and pseudo-germ-free (PGF) rats. Subsequently, we systematically screen the microflora and related metabolites changing in IS via an integrated approach of cecal 16S rRNA sequencing combined with plasma metabolomics. We found that NMT relied on intestinal flora to improve stroke outcome in conventionalized rats while the protection of NMT was reduced in PGF rats. Total 35 differential bacterial genera and 26 differential microbial metabolites were regulated by NMT. Furthermore, L-asparagine and indoleacetaldehyde were significantly negatively correlated with Lachnospiraceae_UCG.001 and significantly positively correlated with Lachnoclostridium. Indoleacetaldehyde also presented a negative correlation with Lactobacillus and Bifidobacterium. 2-Hydroxybutyric acid was strongly negatively correlated with Ruminococcus, Lachnospiraceae_UCG.001 and Lachnospiraceae_UCG.006. Creatinine was strongly negatively correlated with Akkermansia. In summary, the research provided insights into the intricate interaction between intestinal microbiota and metabolism of NMT in IS. We identified above differential bacteria and differential endogenous metabolites which could be as prebiotic and probiotic substances that can influence prognosis in stroke and have potential to be used as novel therapeutic targets or exogenous drug supplements.

Rhubarb Enema Increasing Short-Chain Fatty Acids that Improves the Intestinal Barrier Disruption in CKD May Be Related to the Regulation of Gut Dysbiosis

The incidence of CKD seriously endangers people's health. Researchers have proposed that improving the intestinal barrier damage in CKD may be an effective target for delaying the progression of CKD. Rhubarb can effectively improve the intestinal barrier and renal fibrosis, which may be related to the regulation of gut dysbiosis, but the mechanism needs to be further studied. Short-chain fatty acids (SCFAs) are important metabolites of the gut microbiota and play an important role in maintaining the intestinal barrier. The purpose of this study was to investigate whether rhubarb enema regulates the production of short-chain fatty acid-related gut microbiota and improves the intestinal barrier damage of CKD. 5/6 nephrectomy rats were used as the animal model, sevelamer was used as the positive control group, and the sham operation rats were used as the control group. After 4 weeks of enema treatment, the general clinical indicators, short-chain fatty acid levels, renal pathology, intestinal tissue pathology, intestinal tight junction protein, and changes in gut microbiota were detected. The results showed that rhubarb enema can increase the level of short-chain fatty acids in the 5/6 nephrectomy model rats, improve the intestinal barrier damage, inhibit the decrease of intestinal tight junction proteins, reduce inflammation levels, improve kidney pathology, reduce blood creatinine levels, and regulate the intestinal tract, the abundance, and composition of the flora. Further correlation analysis showed that rhubarb enema increased the level of short-chain fatty acids in 5/6 nephrectomy model rats, which may be related to the 7 strains that may regulate the production of short-chain fatty acids. This study indicated that rhubarb enema can improve the intestinal barrier damage of 5/6 nephrectomy model rats and improve CKD, which may be related to the regulation of short-chain fatty acid-producing gut microbiota.

Effect of fecal microbiota transplantation in patients with slow transit constipation and the relative mechanisms based on the protein digestion and absorption pathway

BACKGROUND

Fecal microbiota transplantation (FMT) is considered an effective treatment for slow transit constipation (STC); nevertheless, the mechanism remains unclear.

METHODS

In this study, eight patients with STC were selected according to the inclusion and exclusion criteria; they then received three treatments of FMT. The feces and serum of STC patients were collected after each treatment and analyzed by integrating 16 s rRNA microbiome and metabolomic analyses.

RESULTS

The results showed that the percentage of clinical improvement reached 62.5% and the rates of patients' clinical remission achieved 75% after the third treatment. At the same time, FMT improved the Wexner constipation scale (WCS), the Gastrointestinal Quality-of-Life Index (GIQLI) and Hamilton Depression Scale (HAMD). Fecal microbiome alpha diversity and beta diversity altered significantly after FMT. Analysis of the 16 s rRNA microbiome showed that the numbers of Bacteroidetes (Prevotell/Bacteroides) and Firmicute (Roseburia/Blautia) decreased, whereas Actinobacteria (Bifidobacterium), Proteobacteria (Escherichia), and Firmicute (Lactobacillus) increased after FMT. The metabolomics analyses showed that the stool of FMT-treated patients were characterized by relatively high levels of N-Acetyl-L-glutamate, gamma-L-glutamyl-L-glutamic acid, Glycerophosphocholine, et al., after FMT. Compared with baseline, the serum of treated patients was characterized by relatively high levels of L-Arginine, L-Threonine, Ser-Arg, Indoleacrylic acid, Phe-Tyr, 5-L-Glutamyl-L-alanine, and lower levels of Erucamide after the treatment. The correlation analysis between the metabolites and gut microbiota showed a significant correlation. For example, L-Arginine was positively correlated with lactobacillus, et al. L-Threonine was positively correlated with Anaerovibrio, Sediminibacterium but negatively correlated with Phascolarctobacterium. Erucamide had significant negative correlations with Sediminibacterium and Sharpea, while being positively correlated with Phascolarctobacterium. Enriched KEGG pathways analysis demonstrated that the protein digestion and absorption pathways gradually upregulated with the increase of FMT frequency. The L-Arginine and L-Threonine were also involved in the pathway. A large amount of Na + was absorbed in the pathway, so that it might increase mucus secretion and electrical excitability of GI smooth muscle.

CONCLUSIONS

Therefore, we speculated that FMT changed the patients' gut microbiota and metabolites involved in the protein digestion and absorption pathways, thereby improving the symptoms of STC. Study on the effectiveness and safety of FMT in the treatment of STC. The study was reviewed and approved by Ethics Committee of Tianjin People's Hospital (ChiCTR2000033227) in 2020.

Multispecies probiotics alter fecal short-chain fatty acids and lactate levels in weaned pigs by modulating gut microbiota

Short-chain fatty acids (SCFAs) are metabolic products produced during the microbial fermentation of non-digestible fibers and play an important role in metabolic homeostasis and overall gut health. In this study, we investigated the effects of supplementation with multispecies probiotics (MSPs) containing Bacillus amyloliquefaciens, Limosilactobacillus reuteri, and Levilactobacillus brevis on the gut microbiota, and fecal SCFAs and lactate levels of weaned pigs. A total of 38 pigs weaned at 4 weeks of age were fed either a basal diet or a diet supplemented with MSPs for 6 weeks. MSP administration significantly increased the fecal concentrations of lactate (2.3-fold; p < 0.01), acetate (1.8-fold; p < 0.05), and formate (1.4-fold; p < 0.05). Moreover, MSP supplementation altered the gut microbiota of the pigs by significantly increasing the population of potentially beneficial bacteria such as Olsenella, Catonella, Catenibacterium, Acidaminococcus, and Ruminococcaceae. MSP supplementation also decreased the abundance of pathogenic bacteria such as Escherichia and Chlamydia. The modulation of the gut microbiota was observed to be strongly correlated with the changes in fecal SCFAs and lactate levels. Furthermore, we found changes in the functional pathways present within the gut, which supports our findings that MSP modulates the gut microbiota and SCFAs levels in pigs. The results support the potential use of MSPs to improve the gut health of animals by modulating SCFAs production.

Lactitol Supplementation Modulates Intestinal Microbiome in Liver Cirrhotic Patients

Background: Cirrhosis is a common chronic liver disease characterized by irreversible diffuse liver damage. Intestinal microbiome dysbiosis and metabolite dysfunction contribute to the development of cirrhosis. Lactitol (4-β-D-galactopyranosyl-D-glucitol) was previously reported to promote the growth of intestinal Bifidobacteria. However, the effect of lactitol on the intestinal microbiome and fecal short-chain fatty acids (SCFAs) and bile acids (BAs) and the interactions among these factors in cirrhotic patients pre- and post-lactitol treatment remain poorly understood. Methods: Here, using shotgun metagenomics and targeted metabolomics methods. Results: we found that health-promoting lactic acid bacteria, including Bifidobacterium longum, B.pseudocatenulatum, and Lactobacillus salivarius, were increased after lactitol intervention, and significant decrease of pathogen Klebsiella pneumonia and associated antibiotic resistant genes /virulence factors. Functionally, pathways including Pseudomonas aeruginosa biofilm formation, endotoxin biosynthesis, and horizontal transfer of pathogenic genes were decreased in cirrhotic patients after 4-week lactitol intervention compared with before treatment. Conclusion: We identified lactitol-associated metagenomic changes, and provide insight into the understanding of the roles of lactitol in modulating gut microbiome in cirrhotic patients.

Helicobacter pylori Eradication Therapy Affect the Gut Microbiota and Ghrelin Levels

Background: Antibiotic therapy used to eradicate Helicobacter pylori has been associated with changes in plasma ghrelin and alterations in the gut microbiota. On the other hand, changes in ghrelin levels have been related to changes in gut microbiota composition. Our aim was to evaluate the relationship between changes in the gut microbiota and ghrelin levels in H. pylori infected patients who received antibiotic treatment for its eradication.

Methods: A prospective case-control study that included forty H. pylori-positive patients who received eradication therapy (omeprazole, clarithromycin, and amoxicillin) and twenty healthy H. pylori antigen-negative participants. Patients were evaluated, including clinical, anthropometric and dietary variables, before and 2 months after treatment. Gut microbiota composition was analyzed through 16S rRNA amplicon sequencing (IlluminaMiSeq).

Results: Changes in gut microbiota profiles and decrease in ghrelin levels were identified after H. pylori eradication treatment. Gut bacteria such as Bifidobacterium longum, Bacteroides, Prevotella, Parabacteroides distasonis, and RS045 have been linked to ghrelin levels fasting and/or post meals. Changes in the abundance of Lachnospiraceae, its genus Blautia, as well as Prevotella stercorea, and Megasphaera have been inversely associated with changes in ghrelin after eradication treatment.

Conclusions: Eradication treatment for H. pylori produces changes in the composition of the intestinal microbiota and ghrelin levels. The imbalance between lactate producers such as Blautia, and lactate consumers such as Megasphaera, Lachnospiraceae, or Prevotella, could trigger changes related to ghrelin levels under the alteration of the eradication therapy used for H. pylori. In addition, acetate producing bacteria such as B. longum, Bacteroides, and P. distasonis could also play an important role in ghrelin regulation.

Dietary synbiotic ameliorates constipation through the modulation of gut microbiota and its metabolic function

The purpose of this study is to investigate the mitigatory effect of a novel synbiotic (SBT) on constipation from the perspective of gut microbiome and metabolome. Here, intake of SBT effectively attenuated diphenoxylate-induced constipation, recuperated colonic epithelial integrity and increased serum levels of gastrointestinal excitatory neurotransmitters (P substance, vasoactive intestinal peptide, motilin, gastrin and serotonin). 16S rRNA sequencing showed that SBT intake rehabilitated the composition and functionality of gut microbiota. Relative abundances of short-chain fatty acids (SCFAs)-producing bacteria including Lactobacillus, Faecalibaculum and Bifidobacterium were elevated by administration of SBT. The gas chromatography-mass spectrometry analysis confirmed that fecal concentrations of propionate and butyrate were significantly increased in the rats intervened with SBT. In addition, SBT ingestion reduced the relative levels of opportunistic pathogens, such as Oscillibacter, Parasutterella and Parabacteroides. Microbial functional prediction showed that the relative abundances of lipopolysaccharide (LPS) biosynthesis and arachidonic acid metabolism were downregulated with SBT administration, which were in accordance with the serum metabolomics results. Furthermore, serum levels of LPS, tumour necrosis factor alpha and interleukin 6 were significantly decreased, indicating that SBT supplementation suppressed inflammatory responses. Therefore, this study demonstrated that consumption of SBT ameliorated constipation possibly by regulating gut microbiota, promoting the SCFAs production and inhibiting inflammatory responses in rats. Our study also indicated that SBT may provide a novel alternative strategy for the treatment of constipation clinically in future.

Maternal Gut Dysbiosis Alters Offspring Microbiota and Social Interactions

Increasing application of antibiotics changes the gut microbiota composition, leading to dysbiosis of the gut microbiota. Although growing evidence suggests the potential role of gut dysbiosis as the cause of neurodevelopmental disorders and behavioral defects, a broad gap of knowledge remains to be narrowed to better understand the exact mechanisms by which maternal gut dysbiosis alters microbiota development and social interactions of offspring. Here, we showed that maternal gut dysbiosis during gestation is a critical determinant of gut microbiota and social interactions off mouse offspring. Gut microbiota of 2-week-old offspring showed significant changes in response to maternal antibiotic treatment. We even detected distinct effects of maternal oral antibiotics on gut microbiota of 14-week-old offspring. Compared to controls, offspring born to antibiotics-treated mothers displayed reduction in sociability and preference for social novelty, suggesting that the altered offspring social behavior was closely linked to dysbiosis of maternal gut microbiota. Our study opens the possibility to better understand the mechanism of how maternal gut microbiota vertically impairs social interactions of offspring in animal models, providing support to the maternal gut microbiota as a potential mediator between offspring microbiota and behaviors.

Effects of inulin and isomalto-oligosaccharide on diphenoxylate-induced constipation, gastrointestinal motility-related hormones, short-chain fatty acids, and the intestinal flora in rats

The prebiotics inulin (INU) and isomalto-oligosaccharide (IMO) influence intestinal health and immunity, but their effects on constipation are not clearly established. We evaluated the effects of INU and IMO in a rat model of diphenoxylate-induced constipation. Twenty-four male rats were divided into four groups: basal diet (Con), 40 mg kg-1 diphenoxylate (PCon), 20 g kg-1 INU and treated with 40 mg kg-1 diphenoxylate, and 20 g kg-1 IMO and treated with 40 mg kg-1 diphenoxylate. INU and IMO increased the number, weight, and water content of fecal pellets, and decreased the time to the first black stool in rats with constipation. Serum levels of the gastrointestinal motility-related hormones adrenocorticotropic hormone (ACTH), motilin (MTL), and Substance P (SP) were higher and corticosterone (CORT), vasoactive intestinal peptide (VIP), and calcitonin gene-related peptide (CGRP) were lower in rats treated with prebiotics than in untreated rats. Colon tissue levels of MTL and SP were increased, and VIP and CGRP were decreased by prebiotics. Furthermore, in rats with constipation, INU and IMO increased the colonic contents of short-chain fatty acids. The relative abundance of Bacteroidetes was lower in the prebiotics groups than in the Con and PCon groups. Lactobacillus was more abundant in the INU and IMO groups than in PCon rats. Lactobacillus reuteri and Lactobacillus intestinalis were more abundant in the IMO group than in the PCon group (P < 0.01), and L. intestinalis was more abundant in the INU group than in the PCon group (P < 0.01). In summary, INU and IMO improved constipation and altered the intestinal microbiota in a rat model of constipation.

Corrigendum to "Positive Effect of Electro-Acupuncture Treatment on Gut Motility in Constipated Mice Is Related to Rebalancing the Gut Microbiota"

[This corrects the article DOI: 10.1155/2021/6652017.].

Fecal microbiota in children with juvenile idiopathic arthritis treated with methotrexate or etanercept

BACKGROUND

Alterations in the composition of the fecal microbiota in children with juvenile idiopathic arthritis (JIA) have been observed in several studies, but it has not been determined whether the standard treatment for JIA changes the composition or function of the microbiota. The first-line disease-modifying anti-rheumatic drug for treatment of JIA is usually methotrexate, followed or supplemented by anti-tumor necrosis factor alpha drugs, such as etanercept. The aim of this study was to investigate the effects of methotrexate and etanercept treatments on the fecal microbiota and the fecal short-chain fatty acids (SCFAs) in children with JIA.

METHODS

In this multicenter study, the composition of fecal microbiota from 45 treatment-naïve children with JIA was compared with that from 29 children treated with methotrexate and 12 children treated with etanercept. We also made pairwise comparisons of 15 children sampled before and during methotrexate treatment and 7 children sampled before and during etanercept treatment. The microbiota was determined using sequencing amplicons from the V3 and V4 regions of the 16S rRNA gene. Alpha-diversity, community composition, and relative abundances of bacterial taxa were analyzed in all comparisons. Analyses of fecal SCFAs, using a high-performance liquid chromatograph, were performed for the pairwise comparisons.

RESULTS

We did not find any significant differences in α-diversity or community composition of microbiota. However, principal coordinate analysis indicated a change in community composition in 7 of the 15 paired samples before and during methotrexate and 2 of the 7 paired samples before and during etanercept. Comparisons of the relative abundance of taxa revealed minor differences before and during treatment with methotrexate or etanercept, but they were not significant after correction for multiple analyses, and the unpaired and paired analyses did not show similar changes. There were no significant differences in levels of fecal SCFAs before and during treatment with methotrexate or etanercept.

CONCLUSIONS

Treatment with methotrexate or etanercept had minor, but no significant or consistent changes either on composition of microbiota or on levels of SCFAs, suggesting that these changes are not related to the therapeutic effects of methotrexate or etanercept.

Synbiotic yogurt containing konjac mannan oligosaccharides and Bifidobacterium animalis ssp. lactis BB12 alleviates constipation in mice by modulating the stem cell factor (SCF)/c-Kit pathway and gut microbiota

Synbiotic dietary supplements, as an effective means of regulating the gut microbiota, may have a beneficial effect on constipation. This study evaluated the effects of synbiotic yogurt containing konjac mannan oligosaccharides (KMOS) and Bifidobacterium animalis ssp. lactis BB12 (BB12) on constipated Kunming mice (the model group). Following administration of yogurt containing 2.0% KMOS and BB12 (YBK2.0), black fecal weight and number and gastrointestinal transit rate increased by 97.5, 106.3, and 55.7%, respectively, compared with the model group. Serum levels of excitability neurotransmitters (motilin, substance P, and acetylcholine) in the YBK2.0 group were increased by 139.7, 120.4, and 91.8%, respectively, and serum levels of inhibitory neurotransmitters (vasoactive intestinal peptide, nitric oxide, and acetylcholine) were decreased. Moreover, synbiotic yogurt supplementation significantly downregulated the expression of vasoactive intestinal peptide receptor 1 (VIPR1) and upregulated the expression of serotonin receptor 4 (5-HT4) in the colon, and enhanced the expression of the stem cell factor (SCF)/c-Kit pathway. Additionally, YBK2.0 treatment significantly regulated the community composition and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of gut microbiota, which were positively correlated with physiological parameters of constipation. Thus, supplementation with synbiotic yogurt composed of KMOS and BB12 could facilitate fecal excretion by regulating related pathways and the gut microbiota. These findings demonstrated that the synbiotic yogurt can be considered a functional food for alleviating constipation.

Gut Microbiota Composition Changes in Constipated Women of Reproductive Age

Background

Chronic constipation is one of the most prevalent functional gastrointestinal disorders, yet its etiology is multifactorial, and the pathophysiological mechanism is still unclear. Previous studies have shown that the gut microbiota of constipated patients differs from healthy controls; however, many discrepancies exist in the findings, and no clear link has been confirmed between chronic constipation and changes in the gut microbiota. Growing evidence indicates that age, gender, and hormone levels can affect the composition of gut microbiota. The aim of this study is to examine the overall changes in gut microbiota within a specific sub-population of patients, namely, constipated women of reproductive age.

Methods

We carried out a cross-sectional study comparing the fecal microbial composition of 30 healthy women and 29 constipated women using 16S rRNA gene sequencing. Only women of reproductive age were recruited to reduce the effects of age, gender, and hormone levels on the microbiome, and to prevent conflating the impact of these factors with the effects of constipation.

Results

There were obvious differences in the gut microbiota in constipated women of reproductive age compared with the healthy controls, manifesting mainly as a significant increase in the abundance of Bacteroides (p < 0.05) and a significant decrease in the abundance of Proteobacteria (p < 0.01). The overall composition of the gut microbiota in each group was different, which was reflected in the ratios of Firmicutes to Bacteroidetes (F/B), which was 1.52 in the constipated group vs. 2.21 in the healthy group. Additionally, there was a significant decrease in butyrate-producing bacteria, like Roseburia and Fusicatenibacter (p < 0.01).

Conclusion

The overall composition of the gut microbiota changed in constipated women of reproductive age, characterized by a loss in Proteobacteria and an increase in Bacteroidetes. Furthermore, the abundance of some butyrate-producing bacteria also reduced. These changes may reflect the unique interactions between host and some bacteria, or some bacterial metabolic products, which may be important targets for future studies to explore the pathogenesis of constipation.

The gut microbiome: a key player in the complexity of amyotrophic lateral sclerosis (ALS)

BACKGROUND

Much progress has been made in mapping genetic abnormalities linked to amyotrophic lateral sclerosis (ALS), but the majority of cases still present with no known underlying cause. Furthermore, even in families with a shared genetic abnormality there is significant phenotypic variability, suggesting that non-genetic elements may modify pathogenesis. Identification of such disease-modifiers is important as they might represent new therapeutic targets. A growing body of research has begun to shed light on the role played by the gut microbiome in health and disease with a number of studies linking abnormalities to ALS.

MAIN BODY

The microbiome refers to the genes belonging to the myriad different microorganisms that live within and upon us, collectively known as the microbiota. Most of these microbes are found in the intestines, where they play important roles in digestion and the generation of key metabolites including neurotransmitters. The gut microbiota is an important aspect of the environment in which our bodies operate and inter-individual differences may be key to explaining the different disease outcomes seen in ALS. Work has begun to investigate animal models of the disease, and the gut microbiomes of people living with ALS, revealing changes in the microbial communities of these groups. The current body of knowledge will be summarised in this review. Advances in microbiome sequencing methods will be highlighted, as their improved resolution now enables researchers to further explore differences at a functional level. Proposed mechanisms connecting the gut microbiome to neurodegeneration will also be considered, including direct effects via metabolites released into the host circulation and indirect effects on bioavailability of nutrients and even medications.

CONCLUSION

Profiling of the gut microbiome has the potential to add an environmental component to rapidly advancing studies of ALS genetics and move research a step further towards personalised medicine for this disease. Moreover, should compelling evidence of upstream neurotoxicity or neuroprotection initiated by gut microbiota emerge, modification of the microbiome will represent a potential new avenue for disease modifying therapies. For an intractable condition with few current therapeutic options, further research into the ALS microbiome is of crucial importance.

Effects of Transanal Irrigation on Gut Microbiota in Pediatric Patients with Spina Bifida

Recent studies using 16S rRNA-based microbiota profiling have demonstrated dysbiosis of gut microbiota in constipated patients. The aim of this study was to investigate the changes in gut microbiota after transanal irrigation (TAI) in patients with spina bifida (SB). A questionnaire on neurogenic bowel disfunction (NBD), Bristol scale, and gut microbiota using 16S rRNA sequencing were completed in 16 SB patients and 10 healthy controls aged 6–17 years. Then, 11 of 16 SB patients with moderate to severe NBD scores received TAI for 3 months. Changes in urine cultures were also examined before and after the TAI treatments. In addition, correlation of gut microbiota and Bristol scale was analyzed. Significantly decreased abundance in Faecalibacterium, Blautia and Roseburia, and significantly increased abundance in Bacteroides and Roseburia were observed in the SB patients compared with controls and after TAI, respectively. The abundance of Roseburia was significantly correlated positively with Bristol scale. Urinary tract infection tended to decrease from 82% to 55% after TAI (p = 0.082) despite persistent fecal incontinence. Butyrate-producing bacteria such as Roseburia play a regulatory role in the intestinal motility and host immune system, suggesting the effects of TAI on gut microbiota.

Myelin as a regulator of development of the microbiota-gut-brain axis

Myelination in the peripheral and central nervous systems is critical in regulating motor, sensory, and cognitive functions. As myelination occurs rapidly during early life, neonatal gut dysbiosis during early colonization can potentially alter proper myelination by dysregulating immune responses and neuronal differentiation. Despite common usage of antibiotics (Abx) in children, the impact of neonatal Abx-induced dysbiosis on the development of microbiota, gut, brain (MGB) axis, including myelination and behavior, is unknown. We hypothesized that neonatal Abx-induced dysbiosis dysregulates host-microbe interactions, impairing myelination in the brain, and altering the MGB axis. Neonatal C57BL/6 mice were orally gavaged daily with an Abx cocktail (neomycin, vancomycin, ampicillin) or water (vehicle) from postnatal day 7 (P7) until weaning (P23) to induce gut dysbiosis. Behavior (cognition; anxiety-like behavior), microbiota sequencing, and qPCR (ileum, colon, hippocampus and pre-frontal cortex [PFC]) were performed in adult mice (6-8 weeks). Neonatal Abx administration led to intestinal dysbiosis in adulthood, impaired intestinal physiology, coupled with perturbations of bacterial metabolites and behavioral alterations (cognitive deficits and anxiolytic behavior). Expression of myelin-related genes (Mag, Mog, Mbp, Mobp, Plp) and transcription factors (Sox10, Myrf) important for oligodendrocytes were significantly increased in the PFC region of Abx-treated mice. Increased myelination was confirmed by immunofluorescence imaging and western blot analysis, demonstrating increased expression of MBP, SOX10 and MYRF in neonatally Abx-treated mice compared to sham controls in adulthood. Finally, administration of the short chain fatty acid butyrate following completion of the Abx treatment restored intestinal physiology, behavior, and myelination impairments, suggesting a critical role for the gut microbiota in mediating these effects. Taken together, we identified a long-lasting impact of neonatal Abx administration on the MGB axis, specifically on myelin regulation in the PFC region, potentially contributing to impaired cognitive function and bacterial metabolites are effective in reversing this altered phenotype.

Prevention of loperamide induced constipation in mice by KGM and the mechanisms of different gastrointestinal tract microbiota regulation

Constipation is one of the most prevalent gastrointestinal tract diseases. Konjac glucomannan (KGM) dietotherapy can effectively relieve the clinical symptoms of patients with constipation. However, the causal relationship among KGM, constipation and different gastrointestinal microbiome (i.e., the stomach {St}, small intestine {S}, and large intestine {L}) remains poorly understood. In this study, constipated mice were treated with KGM (75, 150, 300 mg/kg bw). Results showed that KGM treatment improved the general physiological state, fecal character, small intestinal propulsive rate, gastric emptying rate, MTL and AchE activities, ET-1, 5-HT, and NO levels, and SCFA concentrations. KGM in the diets of constipated mice reduced the diversity of St and S microbiota, while increased those in the L. The KGM intervention regulated the microbiota profile, which afterwards was closer to the normal mouse group: confirmation was provided by different changes of bacteria like Lactobacillus, Bifidobacterium and Allobaculum spp et al.

Chitosan oligosaccharides attenuate loperamide-induced constipation through regulation of gut microbiota in mice

This study was designed to explore the improvement of chitosan oligosaccharides (COS) on constipation through regulation of gut microbiota. Here, we proved that COS treatment profoundly boosted intestinal motility, restrained inflammatory responses, improved water-electrolyte metabolism and prevented gut barrier damage in constipated mice induced by loperamide. By 16S rDNA gene sequencing, the disbalanced gut microbiota was observed in constipated mice, while COS treatment statistically reversed the abundance changes of several intestinal bacteria at either phylum, family and genus levels, which partly led to the balance in production of intestinal metabolites including bile acids, short-chain fatty acids and tryptophan catabolites. In addition, COS failed to relieve the constipation in mice with intestinal flora depletion, confirming the essentiality of gut microbiota in COS-initiated prevention against constipation. In summary, COS can ameliorate the development of loperamide-induced constipation in mice by remodeling the structure of gut microbial community.

The impact of Helicobacter pylori infection on gut microbiota-endocrine system axis; modulation of metabolic hormone levels and energy homeostasis

The gut microbiota is a complex ecosystem that is involved in the development and preservation of the immune system, energy homeostasis and nutritional status of the host. The crosstalk between gut microbiota and the host cells modulates host physiology and metabolism through different mechanisms. Helicobacter pylori (H. pylori) is known to reside in the gastric mucosa, induce inflammation, and alter both gastric and intestinal microbiota resulting in a broad spectrum of diseases, in particular metabolic syndrome-related disorders. Infection with H. pylori have been shown to affect production level and physiological regulation of the gut metabolic hormones such as ghrelin and leptin which are involved in food intake, energy expenditure and body mass. In this study, we reviewed and discussed data from the literature and follow-up investigations that links H. pylori infection to alterations of the gut microbiota and metabolic hormone levels, which can exert broad influences on host metabolism, energy homeostasis, behavior, appetite, growth, reproduction and immunity. Also, we discussed the strong potential of fecal microbiota transplantation (FMT) as an innovative and promising investigational treatment option for homeostasis of metabolic hormone levels to overcome H. pylori-associated metabolic syndrome-related disorders.

27-Hydroxycholesterol contributes to cognitive deficits in APP/PS1 transgenic mice through microbiota dysbiosis and intestinal barrier dysfunction

Background

Research on the brain-gut-microbiota axis has led to accumulating interest in gut microbiota dysbiosis and intestinal barrier dysfunction in Alzheimer’s disease (AD). Our previous studies have demonstrated neurotoxic effects of 27-hydroxycholesterol (27-OHC) in in vitro and in vivo models. Here, alterations in the gut microbiota and intestinal barrier functions were investigated as the possible causes of cognitive deficits induced by 27-OHC treatment.

Methods

Male APP/PS1 transgenic and C57BL/6J mice were treated for 3 weeks with 27-OHC (5.5 mg/kg/day, subcutaneous injection) and either a 27-OHC synthetase inhibitor (anastrozole, ANS) or saline. The Morris water maze and passive avoidance test were used to assess cognitive impairment. Injuries of the intestine were evaluated by histopathological examination. Intestinal barrier function was assessed by plasma diamine oxidase (DAO) activity and d-lactate. Systemic and intestinal inflammation were evaluated by IL-1β, TNF-α, IL-10, and IL-17 concentrations as determined by ELISA. The fecal microbiome and short-chain fatty acids (SCFAs) were analyzed using 16S rDNA sequencing and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Tight junction proteins were evaluated in the ileum and colon by qRT-PCR and Western blots. Tight junction ultrastructure was examined by transmission electron microscopy.

Results

Treatment with 27-OHC resulted in severe pathologies in the ileum and colon. There was impaired intestinal barrier integrity as indicated by dilated tight junctions and downregulation of tight junction proteins, including occludin, claudin 1, claudin 5, and ZO-1, and signs of inflammation (increased IL-1β, TNF-α, and IL-17). Fecal 16S rDNA sequencing and taxonomic analysis further revealed a decreased abundance of Roseburia and reduced fecal levels of several SCFAs in 27-OHC-treated mice. Meanwhile, co-treatment with ANS reduced intestinal inflammation and partially preserved intestinal barrier integrity in the presence of 27-OHC.

Conclusions

The current study demonstrates for the first time that 27-OHC treatment aggravates AD-associated pathophysiological alterations, specifically gut microbiota dysbiosis and intestinal barrier dysfunction, which suggests that the gut microbiome and intestinal barrier function warrant further investigation as potential targets to mitigate the neurotoxic impact of 27-OHC on cognitive function and the development of AD.

Photoperiod modulates the gut microbiome and aggressive behavior in Siberian hamsters

Seasonally breeding animals undergo shifts in physiology and behavior in response to changes in photoperiod (day length). Interestingly, some species, such as Siberian hamsters (Phodopus sungorus), are more aggressive during the short-day photoperiods of the non-breeding season, despite gonadal regression. While our previous data suggest that Siberian hamsters employ a 'seasonal switch' from gonadal to adrenal regulation of aggression during short-day photoperiods, there is emerging evidence that the gut microbiome, an environment of symbiotic bacteria within the gastrointestinal tract, may also change seasonally and modulate social behaviors. The goal of this study was to compare seasonal shifts in the gut microbiome, circulating levels of adrenal dehydroepiandrosterone (DHEA) and aggression in male and female Siberian hamsters. Hamsters were housed in either long-day (LD) or short-day (SD) photoperiods for 9 weeks. Fecal samples were collected and behaviors were recorded following 3, 6 and 9 weeks of housing, and circulating DHEA was measured at week 9. SD females that were responsive to changes in photoperiod (SD-R), but not SD-R males, displayed increased aggression following 9 weeks of treatment. SD-R males and females also exhibited distinct changes in the relative abundance of gut bacterial phyla and families, yet showed no change in circulating DHEA. The relative abundance of some bacterial families (e.g. Anaeroplasmataceae in females) was associated with aggression in SD-R but not LD or SD non-responder (SD-NR) hamsters after 9 weeks of treatment. Collectively, this study provides insight into the complex role of the microbiome in regulating social behavior in seasonally breeding species.