Effects of Different Doses of Fructooligosaccharides (FOS) on the Composition of Mice Fecal Microbiota, Especially the Bifidobacterium Composition

Effects of fructooligosaccharides and Saccharomyces boulardii on the compositional structure and metabolism of gut microbiota in students

Fructooligosaccharides (FOS) are a common prebiotic widely used in functional foods. Meanwhile, Saccharomyces boulardii is a fungal probiotic frequenly used in the clinical treatment of diarrhea. Compared with single use, the combination of prebiotics and probiotics as symbiotics may be more effective in regulating gut microbiota as recently reported in the literature. The present study aimed to investigate the effects of FOS, S. boulardii and their combination on the structure and metabolism of the gut microbiota in healthy primary and secondary school students using an in vitro fermentation model. The results indicated that S. boulardii alone could not effectively regulate the community structure and metabolism of the microbiota. However, both FOS and the combination of FOS and S. boulardii could effectively regulate the microbiota, significantly inhibiting the growth of Escherichia-Shigella and Bacteroides, and controlling the production of the gases including H2S and NH3. In addition, both FOS and the combination could significantly promote the growth of Bifidobacteria and Lactobacillus, lower environmental pH, and enhance several physiological functions related to synthesis and metabolism. Nevertheless, the combination had more unique benefits as it promoted the growth of Lactobacillus, significantly increased CO2 production and enhanced the functional pathways of carbon metabolism and pyruvic acid metabolism. These findings provide guidance for clinical application and a theoretical basis for the development of synbiotic preparations.

Endurance exercise associated with a fructooligosaccharide diet modulates gut microbiota and increases colon absorptive area

BACKGROUND AND AIM

Fructooligosaccharide (FOS) supplementation can stimulate beneficial intestinal bacteria growth, but little is known about its influence on training performance. Therefore, this study analyzed FOS and exercise effects on gut microbiota and intestinal morphology of C57Bl/6 mice.

METHODS

Forty male mice were divided into four groups: standard diet-sedentary (SDS), standard diet-exercised (SDE), FOS supplemented (7.5% FOS)-sedentary (FDS), and FOS supplemented-exercised (FDE), n = 10 each group. Exercise training consisted of 60 min/day, 3 days/week, for 12 weeks.

RESULTS

SDE and FDE groups had an increase in aerobic performance compared to the pretraining period and SDS and FDS groups (P < 0.01), respectively. Groups with FOS increased colonic crypts size (P < 0.05). The FDE group presented rich microbiota (α-diversity) compared to other groups. The FDE group also acquired a greater microbial abundance (β-diversity) than other groups. The FDE group had a decrease in the Ruminococcaceae (P < 0.002) and an increase in Roseburia (P < 0.003), Enterorhabdus (P < 0.004) and Anaerotruncus (P < 0.006).

CONCLUSIONS

These findings suggest that aerobic exercise associated with FOS supplementation modulates gut microbiota and can increase colonic crypt size without improving endurance exercise performance.

Intervention with fructooligosaccharides, Saccharomyces boulardii, and their combination in a colitis mouse model

Objective

To examine the effects of an intervention with fructooligosaccharides (FOS), Saccharomyces boulardii, and their combination in a mouse model of colitis and to explore the mechanisms underlying these effects.

Methods

The effects of FOS, S. boulardii, and their combination were evaluated in a DSS-induced mouse model of colitis. To this end, parameters such as body weight, the disease activity index (DAI), and colon length were examined in model mice. Subsequently, ELISA was employed to detect the serum levels of proinflammatory cytokines. Histopathological analysis was performed to estimate the progression of inflammation in the colon. Gas chromatography was used to determine the content of short-chain fatty acids (SCFAs) in the feces of model mice. Finally, 16S rRNA sequencing technology was used to analyze the gut microbiota composition.

Results

FOS was slight effective in treating colitis and colitis-induced intestinal dysbiosis in mice. Meanwhile, S. boulardii could significantly reduced the DAI, inhibited the production of IL-1β, and prevented colon shortening. Nevertheless, S. boulardii treatment alone failed to effectively regulate the gut microbiota. In contrast, the combined administration of FOS/S. boulardii resulted in better anti-inflammatory effects and enabled microbiota regulation. The FOS/S. boulardii combination (109 CFU/ml and 107 CFU/ml) significantly reduced the DAI, inhibited colitis, lowered IL-1β and TNF-α production, and significantly improved the levels of butyric acid and isobutyric acid. However, FOS/S. boulardii 109 CFU/ml exerted stronger anti-inflammatory effects, inhibited IL-6 production and attenuated colon shortening. Meanwhile, FOS/S. boulardii 107 CFU/ml improved microbial regulation and alleviated the colitis-induced decrease in microbial diversity. The combination of FOS and S. boulardii significantly increased the abundance of Parabacteroides and decreased the abundance of Escherichia-Shigella. Additionally, it promoted the production of acetic acid and propionic acid.

Conclusion

Compared with single administration, the combination can significantly increase the abundance of beneficial bacteria such as lactobacilli and Bifidobacteria and effectively regulate the gut microbiota composition. These results provide a scientific rationale for the prevention and treatment of colitis using a FOS/S. boulardii combination. They also offer a theoretical basis for the development of nutraceutical preparations containing FOS and S. boulardii.

Fructooligosaccharides Intake during Pregnancy Improves Metabolic Phenotype of Offspring in High Fat Diet-Induced Obese Mice

SCOPE

Obesity and metabolic diseases are closely associated, and individuals who become obese are also prone to type 2 diabetes and cardiovascular disorders. Gut microbiota is mediated by diet and can influence host metabolism and the incidence of metabolic disorders. Recent studies have suggested that improving gut microbiota through a fructooligosaccharide (FOS)-supplemented diet may ameliorate obesity and other metabolic disorders. Although accumulating evidence supports the notion of the developmental origins of health and disease, the underlying mechanisms remain obscure.

METHODS AND RESULTS

ICR mice are fed AIN-93G formula-based cellulose -, FOS-, acetate-, or propionate-supplemented diets during pregnancy. Offspring are reared by conventional ICR foster mothers for 4 weeks; weaned mice are fed high fat diet for 12 weeks and housed individually. The FOS and propionate offspring contribute to suppressing obesity and improving glucose intolerance. Gut microbial compositions in FOS-fed mothers and their offspring are markedly changed. However, the beneficial effect of FOS diet on the offspring is abolished when antibiotics are administered to pregnant mice.

CONCLUSION

The findings highlight the link between the maternal gut environment and the developmental origin of metabolic syndrome in offspring. These results open novel research avenues into preemptive therapies for metabolic disorders by targeting the maternal gut microbiota.

Combination of vitamin D3 and fructooligosaccharides upregulates colonic vitamin D receptor in C57BL/6J mice and affects anxiety-related behavior in a sex-specific manner

Depression and anxiety disorders are among the most common mental health disorders that affect US adults today, frequently related to vitamin D (VD) insufficiency. Along with VD, growing evidence suggests gut microbiota likely play a role in neuropsychiatric disorders. Here, we investigated if modulation of gut microbiota would disrupt host VD status and promote behaviors related to depression and anxiety in adult mice. Six-week-old male and female C57BL/6J mice (n = 10/mice/group) were randomly assigned to receive (1) control diet (CTR), control diet treated with antibiotics (AB), control diet with total 5000 IU of VD (VD), VD treated with antibiotics (VD + AB), VD supplemented with 5% w/w fructooligosaccharides (FOS; VF), and VF diet treated with antibiotics (VF + AB), respectively, for 8 weeks. Our study demonstrated that VD status was not affected by antibiotic regimen. VD alone ameliorates anxiety-related behavior in female mice, and that combination with FOS (i.e., VF) did not further improve the outcome. Male mice, in contrast, exhibit greater anxiety with VF, but not VD, when compared with CTR mice. Colonic VD receptor was elevated in VF-treated mice in both sexes, compared with CTR, which was positively correlated to colonic TPH1, a rate-limiting enzyme for serotonin synthesis. Taken together, our data indicate that the effect of VF on anxiety-related behavior is sex-specific, which may partially be attributed to the activation of colonic VD signaling and subsequent serotonin synthesis. The synergistic or additive effect of VD and FOS on mood disorders remained to be investigated.

Colon impairments and inflammation driven by an altered gut microbiota leads to social behavior deficits rescued by hyaluronic acid and celecoxib

BACKGROUND

The exact mechanisms linking the gut microbiota and social behavior are still under investigation. We aimed to explore the role of the gut microbiota in shaping social behavior deficits using selectively bred mice possessing dominant (Dom) or submissive (Sub) behavior features. Sub mice exhibit asocial, depressive- and anxiety-like behaviors, as well as systemic inflammation, all of which are shaped by their impaired gut microbiota composition.

METHODS

An age-dependent comparative analysis of the gut microbiota composition of Dom and Sub mice was performed using 16S rRNA sequencing, from early infancy to adulthood. Dom and Sub gastrointestinal (GI) tract anatomy, function, and immune profiling analyses were performed using histology, RT-PCR, flow cytometry, cytokine array, and dextran-FITC permeability assays. Short chain fatty acids (SCFA) levels in the colons of Dom and Sub mice were quantified using targeted metabolomics. To support our findings, adult Sub mice were orally treated with hyaluronic acid (HA) (30 mg/kg) or with the non-steroidal anti-inflammatory agent celecoxib (16 mg/kg).

RESULTS

We demonstrate that from early infancy the Sub mouse gut microbiota lacks essential bacteria for immune maturation, including Lactobacillus and Bifidobacterium genera. Furthermore, from birth, Sub mice possess a thicker colon mucin layer, and from early adulthood, they exhibit shorter colonic length, altered colon integrity with increased gut permeability, reduced SCFA levels and decreased regulatory T-cells, compared to Dom mice. Therapeutic intervention in adult Sub mice treated with HA, celecoxib, or both agents, rescued Sub mice phenotypes. HA treatment reduced Sub mouse gut permeability, increased colon length, and improved mouse social behavior deficits. Treatment with celecoxib increased sociability, reduced depressive- and anxiety-like behaviors, and increased colon length, and a combined treatment resulted in similar effects as celecoxib administered as a single agent.

CONCLUSIONS

Overall, our data suggest that treating colon inflammation and decreasing gut permeability can restore gut physiology and prevent social deficits later in life. These findings provide critical insights into the importance of early life gut microbiota in shaping gut immunity, functionality, and social behavior, and may be beneficial for the development of future therapeutic strategies.

The mutual interactions among Helicobacter pylori, chronic gastritis, and the gut microbiota: a population-based study in Jinjiang, Fujian

Objectives

Helicobacter pylori (H. pylori) is a type of bacteria that infects the stomach lining, and it is a major cause of chronic gastritis (CG). H. pylori infection can influence the composition of the gastric microbiota. Additionally, alterations in the gut microbiome have been associated with various health conditions, including gastrointestinal disorders. The dysbiosis in gut microbiota of human is associated with the decreased secretion of gastric acid. Chronic atrophic gastritis (CAG) and H. pylori infection are also causes of reduced gastric acid secretion. However, the specific details of how H. pylori infection and CG, especially for CAG, influence the gut microbiome can vary and are still an area of ongoing investigation. The incidence of CAG and infection rate of H. pylori has obvious regional characteristics, and Fujian Province in China is a high incidence area of CAG as well as H. pylori infection. We aimed to characterize the microbial changes and find potential diagnostic markers associated with infection of H. pylori as well as CG of subjects in Jinjiang City, Fujian Province, China.

Participants

Enrollment involved sequencing the 16S rRNA gene in fecal samples from 176 cases, adhering to stringent inclusion and exclusion criteria. For our study, we included healthy volunteers (Normal), individuals with chronic non-atrophic gastritis (CNAG), and those with CAG from Fujian, China. The aim was to assess gut microbiome dysbiosis based on various histopathological features. QIIME and LEfSe analyses were performed. There were 176 cases, comprising 126 individuals who tested negative for H. pylori and 50 who tested positive defined by C14 urea breath tests and histopathological findings in biopsies obtained through endoscopy. CAG was also staged by applying OLGIM system.

Results

When merging the outcomes from 16S rRNA gene sequencing results, there were no notable variations in alpha diversity among the following groups: Normal, CNAG, and CAG; OLGIM I and OLGIM II; and H. pylori positive [Hp (+)] and H. pylori negative [Hp (-)] groups. Beta diversity among different groups show significant separation through the NMDS diagrams. LEfSe analyses confirmed 2, 3, and 6 bacterial species were in abundance in the Normal, CNAG, and CAG groups; 26 and 2 species in the OLGIM I and OLGIM II group; 22 significant phylotypes were identified in Hp (+) and Hp (-) group, 21 and 1, respectively; 9 bacterial species exhibited significant differences between individuals with CG who were Hp (+) and those who were Hp (-).

Conclusion

The study uncovered notable distinctions in the characteristics of gut microbiota among the following groups: Normal, CNAG, and CAG; OLGIM I and OLGIM II; and Hp (+) and Hp (-) groups. Through the analysis of H. pylori infection in CNAG and CAG groups, we found the gut microbiota characteristics of different group show significant difference because of H. pylori infection. Several bacterial genera could potentially serve as diagnostic markers for H. pylori infection and the progression of CG.

Effects of Resistant Starch Infusion, Solely and Mixed with Xylan or Cellulose, on Gut Microbiota Composition in Ileum-Cannulated Pigs

Fermentation of dietary fiber (DF) is beneficial for gut health, but its prebiotic effects are often impeded in the distal large intestine because of the fast degradation of fermentable substrates. One way to enhance the prebiotic effect of DF is to deliver fibers to the lower parts of the gut, which can be achieved by mixing different kinds of fiber. Therefore, in the present study, an ileum-cannulated pig model was employed to investigate the fermentation influence in the large intestine by infusing resistant starch solely (RS, fast fermentable fiber) and mixing with other fibers (xylan or cellulose). Twenty-four ileum-cannulated growing pigs were divided into four groups: one control group receiving saline ileal infusions and three experimental groups infused with RS, RS with xylan, or RS with cellulose. Fecal and plasma samples were analyzed for gut microbiota composition, short-chain fatty acids (SCFAs), and blood biochemistry. Results indicated no significant differences between the RS and control group for the microbiome and SCFA concentration (p > 0.05). However, RS combined with fibers, particularly xylan, resulted in enhanced and prolonged fermentation, marked by an increase in Blautia and higher lactate and acetate production (p < 0.05). In contrast, RS with cellulose infusion enriched bacterial diversity in feces (p < 0.05). Blood biochemistry parameters showed no significant differences across groups (p > 0.05), though a trend of increased glucose levels was noted in the treatment groups (p < 0.1). Overall, RS alone had a limited impact on the distal hindgut microbiota due to rapid fermentation in the proximal gut, whereas combining RS with other fibers notably improved gut microecology by extending the fermentation process.

Multi-copy expression of a protease-resistant xylanase with high xylan degradation ability and its application in broilers fed wheat-based diets

The acidic thermostable xylanase (AT-xynA) has great potential in the feed industry, but its low activity is not conductive to large-scale production, and its application in poultry diets still needs to be further evaluated. In Experiment1, AT-xynA activity increased 3.10 times by constructing multi-copy strains, and the highest activity reached 10,018.29 ± 91.18 U/mL. AT-xynA showed protease resistance, high specificity for xylan substrates, xylobiose and xylotriose were the main hydrolysates. In Experiment2, 192 broilers were assigned into 3 treatments including a wheat-based diet, and the diets supplemented with AT-xynA during the entire period (XY-42) or exclusively during the early stage (XY-21). AT-xynA improved growth performance, while the performance of XY-21 and XY-42 was identical. To further clarify the mechanism underlying the particular effectiveness of AT-xynA during the early stage, 128 broilers were allotted into 2 treatments including a wheat-based diet and the diet supplemented with AT-xynA for 42 d in Experiment3. AT-xynA improved intestinal digestive function and microbiota composition, the benefits were stronger in younger broilers than older ones. Overall, the activity of AT-xynA exhibiting protease resistance and high xylan degradation ability increased by constructing multi-copy strains, and AT-xynA was particularly effective in improving broiler performance during the early stage.

The gut microbiota participates in the effect of linaclotide in patients with irritable bowel syndrome with constipation (IBS-C): a multicenter, prospective, pre-post study

BACKGROUND

Interindividual variation characterizes the relief experienced by constipation-predominant irritable bowel syndrome (IBS-C) patients following linaclotide treatment. Complex bidirectional interactions occur between the gut microbiota and various clinical drugs. To date, no established evidence has elucidated the interactions between the gut microbiota and linaclotide. We aimed to explore the impact of linaclotide on the gut microbiota and identify critical bacterial genera that might participate in linaclotide efficacy.

METHODS

IBS-C patients were administered a daily linaclotide dose of 290 µg over six weeks, and their symptoms were then recorded during a four-week posttreatment observational period. Pre- and posttreatment fecal samples were collected for 16S rRNA sequencing to assess alterations in the gut microbiota composition. Additionally, targeted metabolomics analysis was performed for the measurement of short-chain fatty acid (SCFA) concentrations.

RESULTS

Approximately 43.3% of patients met the FDA responder endpoint after taking linaclotide for 6 weeks, and 85% of patients reported some relief from abdominal pain and constipation. Linaclotide considerably modified the gut microbiome and SCFA metabolism. Notably, the higher efficacy of linaclotide was associated with enrichment of the Blautia genus, and the abundance of Blautia after linaclotide treatment was higher than that in healthy volunteers. Intriguingly, a positive correlation was found for the Blautia abundance and SCFA concentrations with improvements in clinical symptoms among IBS-C patients.

CONCLUSION

The gut microbiota, especially the genus Blautia, may serve as a significant predictive microbe for symptom relief in IBS-C patients receiving linaclotide treatment.

TRIAL REGISTRATION

This trial was registered with the Chinese Clinical Trial Registry (Chictr.org.cn, ChiCTR1900027934).

The use of probiotics and prebiotics in decolonizing pathogenic bacteria from the gut; a systematic review and meta-analysis of clinical outcomes

Repeated exposure to antibiotics and changes in the diet and environment shift the gut microbial diversity and composition, making the host susceptible to pathogenic infection. The emergence and ongoing spread of AMR pathogens is a challenging public health issue. Recent evidence showed that probiotics and prebiotics may play a role in decolonizing drug-resistant pathogens by enhancing the colonization resistance in the gut. This review aims to analyze available evidence from human-controlled trials to determine the effect size of probiotic interventions in decolonizing AMR pathogenic bacteria from the gut. We further studied the effects of prebiotics in human and animal studies. PubMed, Embase, Web of Science, Scopus, and CINAHL were used to collect articles. The random-effects model meta-analysis was used to pool the data. GRADE Pro and Cochrane collaboration tools were used to assess the bias and quality of evidence. Out of 1395 citations, 29 RCTs were eligible, involving 2871 subjects who underwent either probiotics or placebo treatment to decolonize AMR pathogens. The persistence of pathogenic bacteria after treatment was 22%(probiotics) and 30.8%(placebo). The pooled odds ratio was 0.59(95% CI:0.43-0.81), favoring probiotics with moderate certainty (p = 0.0001) and low heterogeneity (I2 = 49.2%, p = 0.0001). The funnel plot showed no asymmetry in the study distribution (Kendall'sTau = -1.06, p = 0.445). In subgroup, C. difficile showed the highest decolonization (82.4%) in probiotics group. Lactobacillus-based probiotics and Saccharomyces boulardii decolonize 71% and 77% of pathogens effectively. The types of probiotics (p < 0.018) and pathogens (p < 0.02) significantly moderate the outcome of decolonization, whereas the dosages and regions of the studies were insignificant (p < 0.05). Prebiotics reduced the pathogens from 30% to 80% of initial challenges. Moderate certainty of evidence suggests that probiotics and prebiotics may decolonize pathogens through modulation of gut diversity. However, more clinical outcomes are required on particular strains to confirm the decolonization of the pathogens. Protocol registration: PROSPERO (ID = CRD42021276045).

Synbiotic Sapota-do-Solimões (Quararibea cordata Vischer) Juice Improves Gut Microbiota and Short-Chain Fatty Acid Production in an In Vitro Model

Sapota-do-Solimões (Quararibea cordata Vischer) is Amazon South América fruit found in Brazil, Colombia, Ecuador, and Peru. The orange-yellow fruit is usually eaten out of hand or as juice. Despite being a source of carotenoids and dietary fibers (pectin) that can reach the colon and act as an energy source for intestinal microbiota, the fruit is rarely known outside of South America. The symbiotic juice was prepared by fermenting the fruit juice with Lacticaseibacillus casei B-442 and adding prebiotic fructooligosaccharides (FOS, 7% w/v). This study evaluated the functional juice immediately after L. casei fermentation (SSJ0) and after 30 days of cold storage (SSJ30) regarding its effect on human colonic microbiota composition after in vitro fermentation. Fecal samples were collected from two healthy female volunteers, and the 16s rRNA gene sequencing analyzed the fecal microbiota composition. In vitro, colonic fermentation was performed using a batch bioreactor to simulate gastrointestinal conditions. The L. casei viability did not change significantly after 30 days of the synbiotic juice cold storage (4 °C). After the colonic fermentation, the relative abundance of Firmicutes decreased while Proteobacteria and Actinobacteria increased. Regarding short-chain fatty acid (SCFA) production by fecal colonic microbiota, the butyric acid was higher after sample SSJ0 fecal fermentation. In contrast, propionic, isobutyric, and acetic acids were higher after SSJ30 sample fecal fermentation. This study contributes to understanding the interactions between specific foods and the gut microbiota, which can affect human health and well-being.

Plant cell wall composition modulates the gut microbiota and metabolites in in-vitro fermentation

This research investigated the effect of different types of plant cell wall fibres, including cereal (i.e., barley, sorghum, and rice), legume (i.e., pea, faba bean, and mung bean), and tuber (potato, sweet potato, and yam) cell wall fibres on in vitro faecal fermentation profiles and gut microbiota composition. The cell wall composition, specifically the content of lignin and pectin, was found to have a significant influence on the gut microbiota and fermentation outcomes. Compared with type I cell walls (legume and tuber) which have high pectin content, the type II cell walls (cereal) which are high in lignin but low in pectin had a lower fermentation rates and less short-chain fatty acid production. The redundancy analysis showed samples with similar fibre composition and fermentation profiles clustered together, and the principal coordinate analysis revealed separation among different types of cell walls and closer proximity among the same cell wall types. These findings emphasize the importance of cell wall composition in shaping the microbial community during fermentation and contribute to a better understanding of the relationship between plant cell walls and gut health. This research has practical implications for the development of functional foods and dietary interventions.

Synergistic synbiotic containing fructooligosaccharides and Lactobacillus delbrueckii CIDCA 133 alleviates chemotherapy-induced intestinal mucositis in mice

Intestinal mucositis is a commonly reported side effect in oncology patients undergoing chemotherapy and radiotherapy. Probiotics, prebiotics, and synbiotics have been investigated as alternative therapeutic approaches against intestinal mucositis due to their well-known anti-inflammatory properties and health benefits to the host. Previous studies showed that the potential probiotic Lactobacillus delbrueckii CIDCA 133 and the prebiotic Fructooligosaccharides (FOS) alleviated the 5-Fluorouracil (5-FU) chemotherapy-induced intestinal mucosa damage. Based on these previous beneficial effects, this work evaluated the anti-inflammatory property of the synbiotic formulation containing L. delbrueckii CIDCA 133 and FOS in mice intestinal mucosa inflammation induced by 5-FU. This work showed that the synbiotic formulation was able to modulate inflammatory parameters, including reduction of cellular inflammatory infiltration, gene expression downregulation of Tlr2, Nfkb1, and Tnf, and upregulation of the immunoregulatory Il10 cytokine, thus protecting the intestinal mucosa from epithelial damage caused by the 5-FU. The synbiotic also improved the epithelial barrier function by upregulating mRNA transcript levels of the short chain fatty acid (SCFA)-associated GPR43 receptor and the occludin tight junction protein, with the subsequent reduction of paracellular intestinal permeability. The data obtained showed that this synbiotic formulation could be a promising adjuvant treatment to be explored against inflammatory damage caused by 5-FU chemotherapy.

Intestinal microbiomics and hepatic metabolomics insights into the potential mechanisms of probiotic Bifidobacterium pseudolongum CCFM1253 preventing acute liver injury in mice

BACKGROUND

Bifidobacterium pseudolongum is widely exists in mammal gut and its abundance is associated with human and animal health. The present study aimed to investigate the potential mechanisms of B. pseudolongum CCFM1253 on protecting against lipopolysaccharide (LPS)-induced acute liver injury (ALI) by metagenomic analysis and liver metabolomic profiles.

RESULTS

Bifidobacterium pseudolongum CCFM1253 preintervention remarkably attenuated the influence of LPS on serum alanine transaminase and aspartate amino transferase activities. B. pseudolongum CCFM1253 preintervention remarkably attenuated the inflammation responses (tumor necrosis factor-α, interleukin-1β, and interleukin-6) and elevated antioxidative enzymes activities [total antioxidant capacity, superoxide dismutase, catalase, and glutathione peroxidase] in ALI mice by intervening in the Nf-kβ and Nrf2 pathways, respectively. Bifidobacterium pseudolongum CCFM1253 treatment elevated the proportion of Alistipes and Bifidobacterium, and decreased the proportion of uncultured Bacteroidales bacterium, Muribaculum, Parasutterella and Ruminococcaceae UCG-010 in ALI mice, which were strongly correlated with the inhibition of inflammation responses and oxidative stress. Untargeted liver metabolomics exhibited that the hepatoprotective efficacy of B. pseudolongum CCFM1253 might be achieved by altering liver metabolites-related riboflavin metabolism, phenylalanine metabolism, alanine, citrate cycle (tricarboxylic acid cycle), and so on. Furthermore, riboflavin exposure could control the contents of malondialdehyde, superoxide dismutase, and catalase in hydrogen peroxide-treated HepG2 cells.

CONCLUSION

Bifidobacterium pseudolongum CCFM1253 can effectively alleviate inflammatory response and oxidative stress, and regulate the intestinal microbiota composition and liver metabolism, and elevate the liver riboflavin content in LPS-treated mice. Therefore, B. pseudolongum CCFM1253 could serves as a potential probiotic to ameliorate the host health. © 2023 Society of Chemical Industry.

Effects of Bifidobacterium with the Ability of 2'-Fucosyllactose Utilization on Intestinal Microecology of Mice

In breast milk, 2'-Fucosyllactose (2'FL) is the most abundant breast milk oligosaccharide and can selectively promote the proliferation of bifidobacteria. This study aimed to explore the effect of ifidobacterial with different utilization capacities of 2'FL on the intestinal microecology of mice. Furthermore, the effects of ifidobacterial with different 2'FL utilization capabilities on mice gut microbiota under the competitive pressure of 2'FL as a carbon source were explored. Compared with the control group, 2'FL, Bifidobacterium (B.) bifidum M130R01M51 + 2'FL, B. longum subsp. Longum CCFM752, and CCFM752 + 2'FL treatments significantly decreased the food intake. Moreover, the water intake, body weight, and fecal water content in all groups showed no significant difference compared with the control group. The combination of B. longum subsp. longum CCFM752 and 2'FL can significantly increase the levels of pro-inflammatory and anti-inflammatory factors. B. bifidum M130R01M51 and mixed strains combined with 2'FL significantly increased the contents of acetic acid and isobutyric acid. The results showed that B. bifidum M130R01M51, B. breve FHuNCS6M1, B. longum subsp. longum CCFM752, and B. longum subsp. infantis SDZC2M4 combined with 2'FL significantly increased the species richness of the gut microbiota. Moreover, B. longum subsp. longum CCFM752 and B. longum subsp. infantis SDZC2M4 significantly increased the abundance of Faecalibaculum and Bifidobacterium, respectively. In conclusion, exploring the impact on intestinal microecology can provide theoretical guidance for the development of personalized prebiotics for different bifidobacteria, which has the potential to improve the ecological imbalance of infant gut microbiota.

Recent Research and Application Prospect of Functional Oligosaccharides on Intestinal Disease Treatment

The intestinal tract is an essential digestive organ of the human body, and damage to the intestinal barrier will lead to various diseases. Functional oligosaccharides are carbohydrates with a low degree of polymerization and exhibit beneficial effects on human intestinal health. Laboratory experiments and clinical studies indicate that functional oligosaccharides repair the damaged intestinal tract and maintain intestinal homeostasis by regulating intestinal barrier function, immune response, and intestinal microbial composition. Functional oligosaccharides treat intestinal disease such as inflammatory bowel disease (IBD) and colorectal cancer (CRC) and have excellent prospects for therapeutic application. Here, we present an overview of the recent research into the effects of functional oligosaccharides on intestinal health.

Fructooligosaccharides (FOS) significantly increased the relative abundance of intestinal B. pseudolongum in mice with different genotypes

Fructooligosaccharides (FOS) promote the proliferation of Bifidobacterium, especially Bifidobacterium pseudolongum in C57BL/6J mice. However, the response of intestinal microbes to FOS is influenced by host genotypes. Therefore, we compared the intestinal microbiota of four commonly used mice before and after FOS intervention, including C57BL/6J, BALB/c, Institute Cancer Research (ICR), and Kunming (KM) mice. The intestinal microbiota of the four genotypes exhibited similarities in composition but differences in relative abundance. Bifidobacterium was significantly increased to different degrees in the four genotypes of mice after FOS intervention, and Akkermansia and Bacteroides were also significantly increased in BALB/c and KM mice. Lactobacillus and Alistipes levels were unchanged or decreased. Within the genus Bifidobacterium, B. pseudolongum was the dominant species in the four genotypes of mice and proliferated significantly after FOS intervention, with dramatic proliferation in C57BL/6J mice (9.49%). Furthermore, eight strains of B. pseudolongum were screened from the feces of mice with four genotypes, and there was a great difference in the ability and manner of utilizing FOS among the strains. The strains from C57BL/6J mice exhibited the strongest utilization of 1-kestose (GF2), whereas other strains could utilize both GF2 and nistose (GF3) weakly. The gut microbial analysis of mice with different genotypes complemented our previous studies. The results provided the background strains of the different mouse genotypes and suggested a correlation between the utilization ability and the response of the strains to FOS. Further studies on the utilization ability of strains and competition in the intestine will contribute to the understanding of the mechanisms of the intestinal microbial response to diet.

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The intestinal microbiota is similar in composition for mice of different genotypes.

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B. pseudolongum predominates in bifidobacteria in mice of different genotypes.

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The relative abundance of B. pseudolongum increases after FOS intake.

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B. pseudolongum strains show different abilities in utilizing FOS.

Effects of a mildly cooked human-grade dog diet on gene expression, skin and coat health measures, and fecal microbiota of healthy adult dogs

Purported benefits of human-grade pet foods include reduced inflammation, enhanced coat quality, and improved gut health, but research is scarce. Therefore, we compared gene expression, skin and coat health measures, and the fecal microbiome of dogs consuming a mildly cooked human-grade or extruded kibble diet. Twenty beagles (BW = 10.25 ± 0.82 kg; age = 3.85 ± 1.84 yr) were used in a completely randomized design. Test diets included: 1) chicken and brown rice recipe [feed-grade; extruded; blue buffalo (BB)]; and 2) chicken and white rice [human-grade; mildly cooked; Just Food for Dogs (JFFD)]. The study consisted of a 4-week baseline when all dogs ate BB, and a 12-week treatment phase when dogs were randomized to either diet (n = 10/group). After the baseline and treatment phases, fresh fecal samples were scored and collected for pH, dry matter (DM), and microbiome analysis; blood samples were collected for gene expression analysis; hair samples were microscopically imaged; and skin was analyzed for delayed-type hypersensitivity (DTH), sebum concentration, hydration status, and transepidermal water loss (TEWL). Data were analyzed as a change from baseline (CFB) using the Mixed Models procedure of SAS (version 9.4). At baseline, fecal pH was higher (P < 0.05) and hair surface score, superoxide dismutase (SOD) expression, and tumor necrosis factor-α (TNF-α) expression was lower (P < 0.05) in dogs allotted to JFFD. The decrease in CFB fecal pH and DM was greater (P < 0.05) in dogs fed JFFD, but fecal scores were not different. The increase in CFB hair surface score was higher (P < 0.05) in dogs fed JFFD. The decrease in CFB TEWL (back region) was greater (P < 0.05) in dogs fed JFFD, but TEWL (inguinal and ear regions), hydration status, and sebum concentrations in all regions were not different. Hair cortex scores and DTH responses were not affected by diet. The increase in CFB gene expression of SOD, COX-2, and TNF-α was greater (P < 0.05) in dogs fed JFFD. PCoA plots based on Bray-Curtis distances of bacterial genera and species showed small shifts over time in dogs fed BB, but dramatic shifts in those fed JFFD. JFFD increased (adj. P < 0.05) relative abundances of 4 bacterial genera, 11 bacterial species, 68 KEGG pathways, and 167 MetaCyc pathways, and decreased (adj. P < 0.05) 16 genera, 25 species, 98 KEGG pathways, and 87 MetaCyc pathways. In conclusion, the JFFD diet dramatically shifted the fecal microbiome but had minor effects on skin and coat measures and gene expression.

Evaluation of the Potential Protective Effects of Lactobacillus Strains against Helicobacter pylori Infection: A Randomized, Double-Blinded, Placebo-Controlled Trial

BACKGROUND

The beneficial effects of probiotic supplementation standard antibiotic therapies for Helicobacter pylori infection have been verified, but the ability of probiotic monotherapy to eradicate H. pylori remains unclear.

AIM

To evaluate the accuracy and efficacy of specific Lactobacillus strains against H. pylori infection.

METHODS

Seventy-eight patients with H. pylori infection were treated with strain L. crispatus G14-5M (L. crispatus CCFM1118) or L. helveticus M2-09-R02-S146 (L. helveticus CCFM1121) or L. plantarum CCFM8610 at a dose of 2 g twice daily for one month. ¹⁴C-urea breath test, the gastrointestinal symptom rating scale, serum pepsinogen concentrations, and serum cytokine concentrations of patients were measured at baseline and end-of-trial to analyze the effect of the Lactobacillus strains in eradicating H. pylori infection and reducing gastrointestinal discomfort in patients. In addition, the composition and abundance of the intestinal microbiota of patients were also measured at end-of-trial.

RESULTS

The ¹⁴C-urea breath test value of the three Lactobacillus treatment groups had decreased significantly, and the eradication rate of H. pylori had increased by the end of the trial. In particular, the eradication rate in the G14-5M treatment group was significantly higher than the placebo group (70.59% vs. 15.38%, P=0.0039), indicating that one-month administration of the G14-5M regimen was sufficient to eradicate H. pylori infection. The ingestion of Lactobacillus strains also ameliorated the gastrointestinal symptom rating scale scores, and the serum interleukin-8 concentrations of H. pylori-infected patients appeared to modulate the gut microbiota of patients. However, none of the Lactobacillus strains had a significant effect on general blood physiological characteristics, serum tumor necrosis factor α concentrations, or serum pepsinogen concentrations in the patients.

CONCLUSION

Three Lactobacillus strains significantly alleviate the gastrointestinal discomfort and the gastric inflammatory response of H. pylori-infected patients. The activity of probiotics in eradicating H. pyloriinfection may be species/strain specific.

Effects of fructooligosaccharides (FOS) on the composition of cecal and fecal microbiota and the quantitative detection of FOS-metabolizing bacteria using species-specific primers

BACKGROUND

Fructooligosaccharides (FOS) are a kind of prebiotic. Previous studies concerning the effect of FOS on intestinal microbiota have focused on Bifidobacterium and Lactobacillus. However, the presence of other FOS-utilizing bacteria makes it necessary to investigate the quantitative changes in these bacterial species in the intestine after FOS intake. In this study, the composition of cecal and fecal microbiota was analyzed using MiSeq sequencing, and the abundance of FOS-utilizing bacteria was detected using quantitative polymerase chain reaction after the oral administration of FOS.

RESULTS

Species-specific primers for FOS-utilizing bacteria were designed with superior amplification efficiency for quantification. After FOS intervention, the relative abundance of Bifidobacterium pseudolongum in feces increased to 17.37% and the abundance reached 2.28 × 10¹⁰  CFU g^-1 . The abundance of Bifidobacterium longum and Bifidobacterium breve did not change significantly. Whereas the abundance of Ligilactobacillus murinus decreased, that of Lactiplantibacillus plantarum, Lacticaseibacillus paracasei, and Lacticaseibacillus rhamnosus remained at approximately 10⁴  CFU g^-1 .

CONCLUSION

Species-specific primers for FOS-utilizing bacteria were successfully developed, and we confirmed that FOS significantly increased the relative abundance and the abundance of B. pseudolongum in mice, while decreasing the proportion of Lactobacillus. The detection of these species using 16S ribosomal DNA sequencing and quantitative polymerase chain reaction showed the same results. Further investigations are needed to reveal the response of the intestinal microbiota to different FOS compositions. These techniques will contribute to future studies about the composition and dynamics of the intestinal microflora. © 2022 Society of Chemical Industry.

Effect of a diet rich in galactose or fructose, with or without fructooligosaccharides, on gut microbiota composition in rats

Recent studies suggest that a diet rich in sugars significantly affects the gut microbiota. Adverse metabolic effects of sugars may partly be mediated by alterations of gut microbiota and gut health parameters, but experimental evidence is lacking. Therefore, we investigated the effects of high intake of fructose or galactose, with/without fructooligosaccharides (FOS), on gut microbiota composition in rats and explored the association between gut microbiota and low-grade systemic inflammation. Sprague-Dawley rats (n = 6/group) were fed the following isocaloric diets for 12 weeks (% of the dry weight of the sugars or FOS): (1) starch (control), (2) fructose (50%), (3) galactose (50%), (4) starch+FOS (15%) (FOS control), (5) fructose (50%)+FOS (15%), (6) galactose (50%)+FOS (15%), and (7) starch+olive (negative control). Microbiota composition in the large intestinal content was determined by sequencing amplicons from the 16S rRNA gene; 341F and 805R primers were used to generate amplicons from the V3 and V4 regions. Actinobacteria, Verrucomicrobia, Tenericutes, and Cyanobacteria composition differed between diets. Bifidobacterium was significantly higher in all diet groups where FOS was included. Modest associations between gut microbiota and metabolic factors as well as with gut permeability markers were observed, but no associations between gut microbiota and inflammation markers were observed. We found no coherent effect of galactose or fructose on gut microbiota composition. Added FOS increased Bifidobacterium but did not mitigate potential adverse metabolic effects induced by the sugars. However, gut microbiota composition was associated with several metabolic factors and gut permeability markers which warrant further investigations.

Dietary citrus pectin drives more ileal microbial protein metabolism and stronger fecal carbohydrate fermentation over fructo-oligosaccharide in growing pigs

Fructo-oligosaccharide (FOS) and pectin are known soluble dietary fibers and can influence gut microbiota and consequently modulate gut health. To understand the differential impact patterns of pectin vs. FOS in modulating gut microbiota in the small and large intestine, an ileal-cannulated pig model was adopted to compare the temporal and spatial effects of FOS and citrus pectin (CP) on the gut microbiota. Sixteen terminal ileal-cannulated pigs were randomly divided into 2 groups and fed with a standard diet supplemented with either 3% FOS or 3% CP for 28 d. The CP group and FOS group showed different microbial composition, especially in the feces, with time and location as major factors affecting microbiota in the CP group, and with only location contribution in the FOS group. In the feces, relative to the FOS group, the CP group showed higher abundance of ChristensenellaceaeR-7 group and RuminococcaceaeUCG-010 and lower abundance of Mitsuokella and Olsenella (adjusted P < 0.05), a higher level of short-chain fatty acids and a lower level of lactate at both d 14 and 25 (P < 0.05), and more copy numbers of genes encoding key enzymes related to propionate (mmdA) and butyrate (BCoAT) production and lactate utilization (LcdA) (P < 0.05), indicating a greater degree of microbial carbohydrate fermentation. In the ileum, as compared with FOS, CP increased the bacteria with high capability of fermenting amino acids, including Escherichia-Shigella and Klebsiella (adjusted P < 0.05), and the expression of enzymes responsible for amino acid fermentation (i.e. lysine decarboxylase), as well as the amino acid fermentation products (cadaverine and tyramine) (P < 0.05), indicating a greater degree of amino acid fermentation. Overall, our results highlight a differential dynamic impact of dietary CP vs. FOS on microbial composition and metabolism in the gut. The dietary CP has a stronger ability to promote microbial amino acid fermentation in the ileum and carbohydrate fermentation in the feces than FOS. These findings provide a new insight into the role of different fibers in gut nutrition and guidelines for the choice of fibers in manipulating gut health.

Dysregulation of intestinal flora: excess prepackaged soluble fibers damage the mucus layer and induce intestinal inflammation

Soluble fiber is commonly used as a dietary supplement to improve intestinal flora, and many prepackaged products are sold in the market. However, whether these prepared soluble fibers are harmless for intestinal flora has not been systematically evaluated. Here, we assessed the dose-effect of fructooligosaccharides (FOSs) on obesity and intestinal flora using a mouse model. Gavage of low- and medium-dose FOS improved the microbiota in high-fat diet fed mice, but high-dose FOS leads to intestinal flatulence, diarrhea and flora disorders, including an increase in Akkermansia muciniphila and Clostridium difficile, which disrupt the mucus barrier and cause intestinal inflammation. Besides, a high dose of xylooligosaccharide by gavage induces symptoms similar to those of FOS in mice. These adverse effects can be alleviated by regulating intestinal flora. In addition, we experimentally proved that supplementary probiotics protect against the negative effects of FOS in obese mice. Therefore, prepackaged soluble fiber supplements need to be taken with caution, and excessive consumption of soluble fibers results in intestinal dysfunction and even induces intestinal inflammation. Combining probiotics and soluble fiber can be considered if necessary.

Effects of the Lipid Profile, Type 2 Diabetes and Medication on the Metabolic Syndrome—Associated Gut Microbiome

Metabolic syndrome (MetSyn) is a major health problem affecting approximately 25% of the worldwide population. Since the gut microbiota is highly connected to the host metabolism, several recent studies have emerged to characterize the role of the microbiome in MetSyn development and progression. To this end, our study aimed to identify the microbiome patterns which distinguish MetSyn from type 2 diabetes mellitus (T2DM). We performed 16S rRNA amplicon sequencing on a cohort of 70 individuals among which 40 were MetSyn patients. The microbiome of MetSyn patients was characterised by reduced diversity, loss of butyrate producers (Subdoligranulum, Butyricicoccus, Faecalibacterium prausnitzii) and enrichment in the relative abundance of fungal populations. We also show a link between the gut microbiome and lipid metabolism in MetSyn. Specifically, low-density lipoproteins (LDL) and high-density lipoproteins (HDL) display a positive effect on gut microbial diversity. When interrogating the signature of gut microbiota in a subgroup of patients harbouring both MetSyn and T2DM conditions, we observed a significant increase in taxa such as Bacteroides, Clostridiales, and Erysipelotrichaceae. This preliminary study shows for the first time that T2DM brings unique signatures of gut microbiota in MetSyn patients. We also highlight the impact of metformin treatment on the gut microbiota. Metformin administration was linked to changes in Prevotellaceae, Rickenellaceae, and Clostridiales. Further research focusing on the microbiome-metabolome patterns is needed to clarify the exact association of various gut microbial communities with the progression of T2DM and the occurrence of various complications in MetSyn patients.

2'-Fucosyllactose Increases the Abundance of Blautia in the Presence of Extracellular Fucosidase-Possessing Bacteria

Blautia is a genus of anaerobic bacteria that is widely distributed in the mammalian gut. Recently, an increasing body of research has demonstrated a link between this genus and human health, suggesting applications as a novel probiotic strain. Moreover, we have previously shown that 2'-fucosyllactose (2'-FL), a major component of human milk oligosaccharides, increases the relative abundance of Blautia sp., particularly Blautia wexlerae, in the cultured fecal microbiota of healthy adults using a pH-controlled single-batch fermenter. However, the effects of 2'-FL on Blautia proliferation vary among individuals. In this study, we assessed the impact of the intrinsic gut microbiota on the prebiotic effects of 2'-FL. Metagenomic analysis of feces collected from all donors showed that the homolog of the intracellular GH95 α-l-fucosidase gene was considerably enriched in two non-responders (individuals who showed no increase in Blautia proliferation), whereas the homologous genes encoding extracellular α-l-fucosidase were more abundant in responders, suggesting that lactose and fucose released into the environment could be substrates mediating the growth of Blautia. In vitro assays confirmed the ability of B. wexlerae to utilize the two carbohydrates but not 2'-FL. We also observed that B. wexlerae utilized fucose released from 2'-FL by Bifidobacterium bifidum, which possessed extracellular GH95 α-l-fucosidase, in co-cultures of these two organisms. Finally, increasing the proportion of extracellular GH95 by the addition of a B. bifidum strain led to Blautia proliferation by 2'-FL in fecal cultures of the two non-responders. These findings provided valuable perspectives on individualized nutritional approaches to properly control the gut microbiota. Future clinical trials are needed to obtain further insights into the characteristics of responders vs. non-responders.

Characteristics and Mediating Effect of Gut Microbiota With Experience of Childhood Maltreatment in Major Depressive Disorder

Gut microbiota and childhood maltreatment are closely related to depressive symptoms. This study aimed to analyze the characteristics of gut microbiota in major depressive disorder (MDD) patients with childhood maltreatment experience and explore the correlation between gut microbiota, childhood maltreatment, and depressive symptoms. A total of 37 healthy controls (HCs) and 53 patients with MDD were enrolled, including 18 MDD patients without childhood maltreatment experience and 35 MDD patients with childhood maltreatment experience. The Hamilton’s Depression Scale (HAMD-24) and Childhood Trauma Questionnaire-Short Form (CTQ-SF) were used to evaluate their depressive symptoms and childhood maltreatment experience, respectively. The composition of gut microbiota was evaluated using 16S rRNA sequencing. Spearman’s correlation analysis was used to evaluate the correlation between different gut microbiota, depressive symptoms and childhood maltreatment. The mediation analysis was used to evaluate the mediating effect of gut microbiota. In the α-diversity analysis, we found that the Simpson index and Pielou’s Evenness index differed significantly between MDD patients without childhood maltreatment experience and HCs. In the β-diversity analysis, principal coordinate analysis (PCoA) showed significant differences between MDD patients without childhood maltreatment experience, MDD patients with childhood maltreatment experience and HCs. Twenty-seven different bacteria were identified through Linear discriminant analysis effect size (LEfSe) analysis at different levels of classification. The analysis of the correlation showed that Blautia, Bifidobacterium, Bacteroides, Roseburia, and Phascolarctobacterium were significantly correlated with HAMD and CTQ-SF scores. The mediation analysis showed that childhood maltreatment had a significant direct effect on the patients’ depressive symptoms, and Blautia, Bifidobacterium, Roseburia had a significant mediating effect. The findings of this study suggested that MDD patients with childhood maltreatment experience had different gut microbiota, which might have a mediating effect on the influence of childhood maltreatment on depressive symptoms.

Red Raspberry and Fructo-Oligosaccharide Supplementation, Metabolic Biomarkers, and the Gut Microbiota in Adults with Prediabetes: A Randomized Crossover Clinical Trial

BACKGROUND

Evidence suggests that the gut microbiota and cardiometabolic status are associated, suggesting dietary interventions that alter the microbiota may affect metabolic health.

OBJECTIVES

We investigated whether supplementation with (poly)phenol-dense red raspberries (RRB), alone or with a fructo-oligosaccharide (FOS) prebiotic, would improve biomarkers of cardiometabolic risk in individuals with prediabetes (PreDM) and insulin resistance (IR) and whether the effects are related to modulation of the gut microbiota.

METHODS

Adults with PreDM-IR (n = 26; mean ± SEM age, 35 ± 2 years; fasting glucose, 5.7 ± 0.1 mmol/L; HOMA-IR, 3.3 ± 0.3) or who were metabolically healthy (reference group; n = 10; age, 31 ± 3 years; fasting glucose, 5.1 ± 0.2 mmol/L; HOMA-IR, 1.1 ± 0.1) participated in a randomized crossover trial with two 4-week supplementation periods, in which they consumed either RRB (125 g fresh equivalents) daily or RRB + 8g FOS daily, separated by a 4-week washout. The primary outcome variable was the change in the gut microbiota composition, assessed by shotgun sequencing before (baseline) and at the end of each supplementation period. Secondary outcomes were changes in glucoregulation, lipid metabolism, anti-inflammatory status, and anthropometry. The trial is registered at ClinicalTrials.gov, NCT03049631.

RESULTS

In PreDM-IR, RRB supplementation reduced hepatic-IR (-30.1% ± 14.6%; P = 0.04) and reduced plasma total and LDL cholesterol [-4.9% ± 1.8% (P = 0.04) and -7.2% ± 2.3% (P = 0.003), respectively] from baseline. Adding FOS (RRB + FOS) improved β-cell function [insulin secretion rate, +70.2% ± 32.8% (P = 0.02); Disposition Index, +94.4% ± 50.2% (P = 0.04)], but had no significant effect on plasma cholesterol compared to baseline. RRB increased Eubacterium eligens (2-fold) and decreased Ruminococcus gnavus (-60% ± 34%), whereas RRB + FOS increased Bifidobacterium spp. (4-fold) and decreased Blautia wexlerae (-23% ± 12%) from baseline (all P values ≤ 0.05). R. gnavus was positively correlated with hepatic-IR, and E. eligens and Bifidobacterium catenulatum were negatively correlated with cholesterol concentrations (P ≤ 0.05).

CONCLUSIONS

Increased Bifidobacterium spp., concurrently with reduced R. gnavus, was associated with metabolic improvements in adults with PreDM-IR, warranting further research on the mechanisms involved in (poly)phenol/FOS-microbial interactions with host metabolism.

Bifidobacterium longum CCFM1077 Ameliorated Neurotransmitter Disorder and Neuroinflammation Closely Linked to Regulation in the Kynurenine Pathway of Autistic-like Rats

The kynurenine pathway (KP) is abnormal in autistic patients and model animals. According to studies on the brain–gut axis, probiotics can help ameliorate the metabolic abnormalities of the KP in patients and model animals with neurological diseases. This study was aimed at evaluating the ability of Bifidobacterium longum (B. longum) CCFM077 to enhance the gut microbiome and KP metabolism and regulate the neurotransmitter levels and neuroinflammation of autistic rats. The KP metabolism of autistic rats was significantly disordered and significantly related to the regulation of neurotransmitter (excitation and inhibition) and neuroglia states. B. longum CCFM1077 could effectively alleviate autistic-like behaviours (repetitive stereotyped behaviour, learning and memory ability, and despair mood) and regulate the KP metabolism in the periphery system (gut and blood) and brain. In particular, B. longum CCFM1077 could significant regulate the quinolinic acid (QUIN) level in the brain and markedly regulate glutamic acid (Glu) and Glu/γ-aminobutyric acid (GABA) levels in the brain while alleviating microglia activity in the cerebellum. Through a correlation analysis, the QUIN level in the brain was strongly related with autistic-like behaviours and neurotransmitter levels (GABA and Glu). The QUIN level may thus be a potential therapeutic marker for treating autism through the intestinal and neural pathways.

Bifidobacteria exhibited stronger ability to utilize fructooligosaccharides, compared with other bacteria in the mouse intestine

BACKGROUND

Fructooligosaccharides (FOS) have been identified as important prebiotics. Previous studies have found that they can significantly promote the proliferation of Bifidobacterium pseudolongum in the mouse intestine. However, it is still unclear which other bacteria in the mouse intestine can utilize FOS, and the differences in the ability to utilize FOS. In this study, the bacteria capable of utilizing FOS were isolated from mice feces and their ability to utilize FOS was compared. Draft genome sequencing was also applied to explain the differences in FOS utilization at the gene levels.

RESULTS

A total of 15 species were isolated from mouse feces and 13 species were able to utilize fructofuranosylnystose (GF2). Eleven species could utilize nistose (GF3), but not Enterococcus hirae and Lactobacillus reuteri. In contrast, 1-kestose (GF4) was hardly utilized. The enzyme activity determination and draft genome sequencing-based analyses revealed that all isolated species used the phosphotransferase system or permease system to transport FOS into the cells before hydrolysis by β-fructofuranosidase. Although β-fructofuranosidase exists in all strains, there are big differences in the corresponding coding genes between bifidobacteria and non-bifidobacteria.

CONCLUSION

Compared with the other isolates, Bifidobacterium species exhibited higher enzyme activity and shorter generation time, leading to a stronger ability to utilize FOS. © 2021 Society of Chemical Industry.

Novel Developments on Stimuli-Responsive Probiotic Encapsulates: From Smart Hydrogels to Nanostructured Platforms

Biomaterials engineering and biotechnology have advanced significantly towards probiotic encapsulation with encouraging results in assuring sufficient bioactivity. However, some major challenges remain to be addressed, and these include maintaining stability in different compartments of the gastrointestinal tract (GIT), favoring adhesion only at the site of action, and increasing residence times. An alternative to addressing such challenges is to manufacture encapsulates with stimuli-responsive polymers, such that controlled release is achievable by incorporating moieties that respond to chemical and physical stimuli present along the GIT. This review highlights, therefore, such emerging delivery matrices going from a comprehensive description of addressable stimuli in each GIT compartment to novel synthesis and functionalization techniques to currently employed materials used for probiotic’s encapsulation and achieving multi-modal delivery and multi-stimuli responses. Next, we explored the routes for encapsulates design to enhance their performance in terms of degradation kinetics, adsorption, and mucus and gut microbiome interactions. Finally, we present the clinical perspectives of implementing novel probiotics and the challenges to assure scalability and cost-effectiveness, prerequisites for an eventual niche market penetration.

Evaluating live microbiota biobanking using an ex vivo microbiome assay and metaproteomics

Biobanking of live microbiota is becoming indispensable for mechanistic and clinical investigations of drug-microbiome interactions and fecal microbiota transplantation. However, there is a lack of methods to rapidly and systematically evaluate whether the biobanked microbiota maintains their cultivability and functional activity. In this study, we use a rapid ex vivo microbiome assay and metaproteomics to evaluate the cultivability and the functional responses of biobanked microbiota to treatment with a prebiotic (fructo-oligosaccharide, FOS). Our results indicate that the microbiota cultivability and their functional responses to FOS treatment were well maintained by freezing in a deoxygenated glycerol buffer at -80°C for 12 months. We also demonstrate that the fecal microbiota is functionally stable for 48 hours on ice in a deoxygenated glycerol buffer, allowing off-site fecal sample collection and shipping to laboratory for live microbiota biobanking. This study provides a method for rapid evaluation of the cultivability of biobanked live microbiota. Our results show minimal detrimental influences of long-term freezing in deoxygenated glycerol buffer on the cultivability of fecal microbiota.

Health improvements of type 2 diabetic patients through diet and diet plus fecal microbiota transplantation

Type 2 diabetes (T2D) is a major public health problem, and gut microbiota dysbiosis has been implicated in the emergence of T2D in humans. Dietary interventions can indirectly influence the health status of patients with type 2 diabetes through their modulatory effects on the intestinal microbiota. In recent years, fecal microbiota transplantation is becoming familiar as a new medical treatment that can rapidly improve intestinal health. We conducted a 90-day controlled open-label trial to evaluate the health improvement ability of a specially designed diet, and the diet combined with fecal microbiota transplantation (FMT). According to our study, both diet and diet plus FMT treatments showed great potential in controlling blood glucose and blood pressure levels. Sequencing the V4 region of 16S rRNA gene on the Illumina MiniSeq platform revealed a shift of intestinal microbial community in T2D patients, and the changes were also observed in response to the treatments. FMT changed the gut microbiota more quickly than diet. Beneficial bacterium, such as Bifidobacterium, increased along the study and was negatively correlated with blood glucose, blood pressure, blood lipid and BMI. Sulfate-reducing bacteria (SRB), Bilophila and Desulfovibrio, decreased significantly after treatment, showed a positive correlation with blood glucose indices. Thus, the specially designed diet is beneficial to improve blood glucose control in diabetic patients, it also showed the potential to reverse dyslipidemia and dysarteriotony.

Blautia-a new functional genus with potential probiotic properties?

Blautia is a genus of anaerobic bacteria with probiotic characteristics that occur widely in the feces and intestines of mammals. Based on phenotypic and phylogenetic analyses, some species in the genera Clostridium and Ruminococcus have been reclassified as Blautia, so to date, there are 20 new species with valid published names in this genus. An extensive body of research has recently focused on the probiotic effects of this genus, such as biological transformation and its ability to regulate host health and alleviate metabolic syndrome. This article reviews the origin and biological characteristics of Blautia and the factors that affect its abundance and discusses its role in host health, thus laying a theoretical foundation for the development of new functional microorganisms with probiotic properties.

Exploring the universal healthy human gut microbiota around the World

The human gut holds a special place in the study of different microbial environments due to growing evidence that the gut microbiota is related to host health. However, despite extensive research, there is still a lack of knowledge about the core taxa forming the gut microbiota and, moreover, available information is biased towards western microbiomes in both genome databases and most core taxa studies. To tackle these limitations, we tested a database enrichment strategy and analyzed public datasets of whole-genome shotgun data, generated from 545 fecal samples, comprising three gradients of westernization. The NT database was selected as a baseline of biological diversity, subsequently being combined with various studies of interest related to the human microbiota. This enrichment strategy made it possible to improve classification capacity, compared to the original unenriched database, regarding the various lifestyles and populations studied. The effects of incomplete-taxonomy metagenome-assembled genomes on genome database enrichment were also examined, revealing that, while they are helpful, they should be used with caution depending on the taxonomic level of interest. Moreover, in terms of high prevalence, the core analysis revealed a conserved set of bacterial taxa in the healthy human gut microbiota worldwide, despite apparent lifestyle differences. Such taxa show a set of traits, metabolic roles, and ancestral status, making them suitable candidates for a hypothetical phylogenetic core of mutualistic microorganisms co-evolving with the human species.

Butyl-fructooligosaccharides modulate gut microbiota in healthy mice and ameliorate ulcerative colitis in a DSS-induced model

Butyl-fructooligosaccharides (B-FOSs) are newly synthesized prebiotics composed of short-chain FOS (GF2, 1-kestose; GF3, nystose; GF4, fructofuranosyl-nystose; GF5, 1-F-(1-b-D-fructofuranosyl)-2-nystose) bound with one or two butyric groups by ester bonds. Previous in...

Colonized Niche, Evolution and Function Signatures of Bifidobacterium pseudolongum within Bifidobacterial Genus

Background: Although genomic features of various bifidobacterial species have received much attention in the past decade, information on Bifidobacterium pseudolongum was limited. In this study, we retrieved 887 publicly available genomes of bifidobacterial species, and tried to elucidate phylogenetic and potential functional roles of B. pseudolongum within the Bifidobacterium genus. Results: The results indicated that B. pseudolongum formed a population structure with multiple monophyletic clades, and had established associations with different types of mammals. The abundance of B. pseudolongum was inversely correlated with that of the harmful gut bacterial taxa. We also found that B. pseudolongum showed a strictly host-adapted lifestyle with a relatively smaller genome size, and higher intra-species genetic diversity in comparison with the other tested bifidobacterial species. For functional aspects, B. pseudolongum showed paucity of specific metabolic functions, and enrichment of specific enzymes degrading complex plant carbohydrates and host glycans. In addition, B. pseudolongum possessed a unique signature of probiotic effector molecules compared with the other tested bifidobacterial species. The investigation on intra-species evolution of B. pseudolongum indicated a clear evolution trajectory in which considerable clade-specific genes, and variation on genomic diversity by clade were observed. Conclusions: These findings provide valuable information for explaining the host adaptability of B. pseudolongum, its evolutionary role, as well as its potential probiotic effects.

Lactobacillus reuteri FYNLJ109L1 Attenuating Metabolic Syndrome in Mice via Gut Microbiota Modulation and Alleviating Inflammation

Metabolic syndrome is caused by an excessive energy intake in a long-term, high-fat and/or high-sugar diet, resulting in obesity and a series of related complications, which has become a global health concern. Probiotics intervention can regulate the gut microbiota and relieve the systemic and chronic low-grade inflammation, which is an alternative to relieving metabolic syndrome. The aim of this work was to explore the alleviation of two different Lactobacillusreuteri strains on metabolic syndrome. Between the two L. reuteri strains, FYNLJ109L1 had a better improvement effect on blood glucose, blood lipid, liver tissue damage and other related indexes than NCIMB 30242. In particular, FYNLJ109L1 reduced weight gain, food intake and fat accumulation. Additionally, it can regulate the gut microbiota, increase IL-10, and reduce IL-6 and tumor necrosis factor-α (TNF-α), as well as liver injury, and further reduce insulin resistance and regulate lipid metabolism disorders. In addition, it could modulate the gut microbiota, particularly a decreased Romboutsia and Clostridium sensu stricto-1, and an increased Acetatifactor. The results indicated that FYNLJ109L1 could improve metabolic syndrome significantly via alleviating inflammation and gut microbiota modulation.

Human gut-derived B. longum subsp. longum strains protect against aging in a D-galactose-induced aging mouse model

BACKGROUND

Probiotics have been used to regulate the gut microbiota and physiology in various contexts, but their precise mechanisms of action remain unclear.

RESULTS

By population genomic analysis of 418 Bifidobacterium longum strains, including 143 newly sequenced in this study, three geographically distinct gene pools/populations, BLAsia1, BLAsia2, and BLothers, were identified. Genes involved in cell wall biosynthesis, particularly peptidoglycan biosynthesis, varied considerably among the core genomes of the different populations, but accessory genes that contributed to the carbohydrate metabolism were significantly distinct. Although active transmission was observed inter-host, inter-country, inter-city, intra-community, and intra-family, a single B. longum clone seemed to reside within each individual. A significant negative association was observed between host age and relative abundance of B. longum, while there was a strong positive association between host age and strain genotype [e.g., single nucleotide polymorphisms in the arginine biosynthesis pathway]. Further animal experiments performed with the B. longum isolates via using a D-galactose-induced aging mouse model supported these associations, in which B. longum strains with different genotypes in arginine biosynthesis pathway showed divergent abilities on protecting against host aging possibly via their different abilities to modify the metabolism of gut microbes.

CONCLUSIONS

This is the first known example of research on the evolutionary history and transmission of this probiotic species. Our results propose a new mechanistic insight for promoting host longevity via the informed use of specific probiotics or molecules. Video abstract.

Lactobacillus rhamnosus FJSYC4-1 and Lactobacillus reuteri FGSZY33L6 alleviate metabolic syndrome via gut microbiota regulation

Metabolic syndrome, which includes a series of metabolic disorders such as hyperglycemia, hyperlipidemia, insulin resistance and obesity, has become a catastrophic disease worldwide. Accordingly, probiotic intervention is a new strategy to alleviate metabolic syndrome, which can adjust the gut microbiota to a certain extent. The aim of the current work was to explore the alleviation of metabolic syndrome by Lactobacillus reuteri and L. rhamnosus. Two L. reuteri and two L. rhamnosus strains were administered to mice with a high-fat diet for 12 weeks. All Lactobacillus strains tested significantly slowed weight gain in the mice. Among four strains, L. reuteri FGSZY33L6 and L. rhamnosus FJSYC4-1 showed the strongest ability to relieve blood glucose disorders, blood lipid disorders, tissue damage, and particularly gut microbiota disorders. Thus, our findings indicate that these strains can regulate the gut microbiota and produce short-chain fatty acids (SCFAs), which can induce satiety hormones, inhibit food intake and increase satiety, and thus improve metabolic syndrome.

Evaluation of common genetic variants in vitamin E-related pathway genes and colorectal cancer susceptibility

Vitamin E is effective for preventing the risk of cancer. However, few studies have elucidated the mechanism of vitamin E in cancer occurrence. Herein, we aimed to identify the genetic variants in vitamin E-related pathway genes associated with colorectal cancer risk. We applied logistic regression models to assess the association between single-nucleotide polymorphisms (SNPs) in vitamin E-related pathway genes and colorectal cancer risk in the Chinese and European population. The false discovery rate (FDR) method was used to correct multiple comparisons. The mRNA and protein expression analysis were evaluated in public database and in-house RNA-Seq data. SCARB1 rs73227586 was identified significantly increased risk of colorectal cancer in the Chinese population (odd ratio (OR) = 1.46, 95% confidence interval (CI) = 1.22-1.75, P = 2.99 × 10^-5). This finding was further validated in the European population (OR = 1.11, 95% CI = 1.02-1.20, P = 1.44 × 10^-2). Additionally, the mRNA and protein expression of SCARB1 were markedly up-regulated in colorectal tumor tissues. Moreover, rs73227586 T allele could increase the minimum free energy (MFE) and weaken binding ability to transcription factor ELL2. Our findings indicated that SCARB1 may play a carcinogenic role in colorectal cancer. Genetic variants in vitamin E-related pathway genes may concern to be predictors of colorectal cancer risk.

The autistic-like behaviors development during weaning and sexual maturation in VPA-induced autistic-like rats is accompanied by gut microbiota dysbiosis

Researches on gut microbiota in autism have mostly focused on children, but the dynamic changes of gut microbiota from weaning to adulthood were still not clear because of the difficulty of diagnosing autism. In this study, autistic-like rats indued by valproate (VPA) were tracked from weaning (end of breastfeeding; four weeks old) to sexual maturation (food; eight weeks old). Autistic-like rats were found to show obvious developmental disorders. During weaning, autistic-like rats only exhibited obvious repetitive stereotyped behaviors, but the autistic-like behaviors were fully apparent upon sexual maturation. Significant differences were observed between the gut microbiota of autistic-like and healthy rats across both age groups. The correlation analysis results revealed that the correlation between behaviors and some microbiota, especially Helicobacter, did not vary with age or diet. The total amount of short-chain fatty acids (SCFAs) decreased, butyric acid metabolism decreased, and propionic acid metabolism increased in the feces of autistic-like rats. The correlation between autistic-like behaviors and the butyric acid and propionic acid levels did not vary with diet or age. Inositol phosphate metabolism, amino acid metabolism, and lipopolysaccharide biosynthesis were significantly associated with autistic-like behaviors. Our results showed that although the microbiota and SCFAs related to autism were affected by age and diet, some remained consistent irrespective of age and diet, and they could be considered two of the factors related to autistic-like behaviors development.

Causal Inference in Microbiome Medicine: Principles and Applications

Microorganisms that colonize the mammalian skin and cavity play critical roles in various physiological functions of the host. Numerous studies have revealed strong associations between the microbiota and multiple diseases. However, association does not mean causation. To clarify the mechanisms underlying microbiota-mediated diseases, research is moving from associative analyses to causation studies. In this article, we first introduce the principles of the computational methods for causal inference, and then discuss the applications of these methods in microbiome medicine. Furthermore, we examine the reliability of theoretically inferred causality by the interventionist framework. Finally, we show the potential of confirmed causality in microbiota-targeted therapy, especially in personalized dietary intervention. We conclude that a comprehensive understanding of the causal relationships between diets, microbiota, host targets, and diseases is critical to future microbiome medicine.

Xylooligosaccharides Increase Bifidobacteria and Lachnospiraceae in Mice on a High-Fat Diet, with a Concomitant Increase in Short-Chain Fatty Acids, Especially Butyric Acid

Effects of xylooligosaccharides (XOSs) as well as a mixture of XOS, inulin, oligofructose, and partially hydrolyzed guar gum (MIX) in mice fed a high-fat diet (HFD) were studied. Control groups were fed an HFD or a low-fat diet. Special attention was paid to the cecal composition of the gut microbiota and formation of short-chain fatty acids, but metabolic parameters were also documented. The XOS group had significantly higher cecum levels of acetic, propionic, and butyric acids than the HFD group, and the butyric acid content was higher in the XOS than in the MIX group. The cecum microbiota of the XOS group contained more Bifidobacteria, Lachnospiraceae, and S24-7 bacteria than the HFD group. A tendency of lower body weight gain was observed on comparing the XOS and HFD groups. In conclusion, the XOS was shown to be a promising prebiotic candidate. The fiber diversity in the MIX diet did not provide any advantages compared to the XOS diet.