Intestinal microbiota in health and disease: Role of bifidobacteria in gut homeostasis

Understanding the role of gut microfloral bifidobacterium in cancer and its potential therapeutic applications

Gut microbiota research has gained a tremendous amount of attention from the scientific community because of its contribution to gut homeostasis, human health, and various pathophysiological conditions. The early colonizer of the human gut, i.e., bifidobacteria, has emerged as an efficient probiotic in various diseased conditions, including cancer. This review explores the pros and cons of Bifidobacterium in various malignancies and various therapeutic strategies. We have illustrated the controversial role of bifidobacteria participating in various malignancies as well as described the current knowledge regarding its use in anticancer therapies. Ultimately, this article also addresses the need for further extensive research in elucidating the mechanism of how bifidobacteria is involved and is indirectly affecting the tumor microenvironment. Exhaustive and large-scale research is also required to solve the controversial questions regarding the involvement of bifidobacteria in cancer research.

Oral Microbiota: The Influences and Interactions of Saliva, IgA, and Dietary Factors in Health and Disease

Recent advances in metagenomic analyses have made it easier to analyze microbiota. The microbiota, a symbiotic community of microorganisms including bacteria, archaea, fungi, and viruses within a specific environment in tissues such as the digestive tract and skin, has a complex relationship with the host. Recent studies have revealed that microbiota composition and balance particularly affect the health of the host and the onset of disease. Influences such as diet, food preferences, and sanitation play crucial roles in microbiota composition. The oral cavity is where the digestive tract directly communicates with the outside. Stable temperature and humidity provide optimal growth environments for many bacteria. However, the oral cavity is a unique environment that is susceptible to pH changes, salinity, food nutrients, and external pathogens. Recent studies have emphasized the importance of the oral microbiota, as changes in bacterial composition and balance could contribute to the development of systemic diseases. This review focuses on saliva, IgA, and fermented foods because they play critical roles in maintaining the oral bacterial environment by regulating its composition and balance. More attention should be paid to the oral microbiota and its regulatory factors in oral and systemic health.

Efficacy of Biejiajian Pill on Intestinal Microbiota in Patients with Hepatitis B Cirrhosis/Liver Fibrosis: A Randomized Double-Blind Controlled Trial

OBJECTIVE

To analyze the efficacy of Biejiajian Pill (BJJP) on intestinal microbiota in patients with hepatitis B cirrhosis/liver fibrosis, and explore its relationship with liver fibrosis.

METHODS

This was a prospective, randomized double-blind controlled trial. Using the stratified block randomization method, 35 patients with hepatitis B liver cirrhosis/liver fibrosis were randomly assigned (1:1) to receive entecavir (0.5 mg/d) combined with BJJP (3 g/time, 3 times a day) or placebo (simulator as control, SC group, simulator 3 g/time, 3 times a day) for 48 weeks. Blood and stool samples were collected from patients at baseline and week 48 of treatment, respectively. Liver and renal functions as well as hematological indices were detected. Fecal samples were analyzed by 16S rDNA V3-V4 high-throughput sequencing, and intestinal microbiota changes in both groups before and after treatment were compared, and their correlations with liver fibrosis were analyzed.

RESULTS

Compared with the SC group, there was no significant difference in liver function, renal function and hematology indices in the BJJP group, however, the improvement rate of liver fibrosis was higher in the BJJP group (94.4% vs. 64.7%, P=0.041). Principal coordinate analysis (PCoA) based on weighted Unifrac distance showed significant differences in intestinal microbiota community diversity before and after BJJP treatment (P<0.01 and P=0.003), respectively. After 48 weeks' treatment, the abundance levels of beneficial bacteria (Bifidobacteria, Lactobacillus, Faecalibacterium and Blautia) increased, whereas the abundance levels of potential pathogenic bacteria, including Escherichia coli, Bacteroides, Ruminococcus, Parabacteroides and Prevotella decreased, among which Ruminococcus and Parabacteroides were significantly positively correlated with degree of liver fibrosis (r=0.34, P=0.04; r=0.38, P=0.02), respectively. The microbiota in the SC group did not change significantly throughout the whole process of treatment.

CONCLUSION

BJJP had a certain regulatory effect on intestinal microbiota of patients with hepatitis B cirrhosis/liver fibrosis (ChiCTR1800016801).

The Role of Bifidobacterium in COVID-19: A Systematic Review

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, mainly causes respiratory and intestinal symptoms and changes in the microbiota of patients. We performed a systematic search in major databases using "Bifidobacterium" and "COVID-19" or "SARS-CoV-2" as key terms to assess the relationship of the genus to COVID-19. After the selection steps, 25 articles were analyzed. Of these, eighteen were observational, and seven were interventional articles that evaluated the use of Bifidobacterium alone or in mix as probiotics for additional treatment of patients with COVID-19. All stages and severities were contemplated, including post-COVID-19 patients. Overall, Bifidobacterium was associated with both protective effects and reduced abundance in relation to the disease. The genus has been found to be abundant in some cases and linked to disease severity. The studies evaluating the use of Bifidobacterium as probiotics have demonstrated the potential of this genus in reducing symptoms, improving pulmonary function, reducing inflammatory markers, alleviating gastrointestinal symptoms, and even contributing to better control of mortality. In summary, Bifidobacterium may offer protection against COVID-19 through its ability to modulate the immune response, reduce inflammation, compete with pathogenic microbes, and maintain gut barrier function. The findings provide valuable insights into the relationship between the disease and the genus Bifidobacterium, highlighting the potential of microbiota modulation in the treatment of COVID-19.

The interplay between Epstein-Barr virus DNA and gut microbiota in the development of arthritis in a mouse model

Epstein-Barr virus (EBV) DNA may influence the development of autoimmune diseases by increasing the production of proinflammatory cytokines. Such cytokines have been associated with inducing the dysbiosis of colonic microbiota, which, in turn, is a risk factor for autoimmune diseases such as rheumatoid arthritis (RA). Therefore, we investigated the role that EBV DNA may play in modulating the intestinal microbiota and consequent exacerbation of arthritis in a mouse model. Mice were treated with collagen (arthritis-inducing agent), EBV DNA and collagen, EBV DNA, or water. Fecal samples were collected from arthritic and control mice, and 16S rRNA sequencing was performed to determine the effect of EBV DNA on the composition of colonic microbiota. EBV DNA causes a change in the alpha diversity of the microbiota resulting in an increased Chao1 microbial richness and decreased Shannon diversity index in the RA mouse model. In addition, the abundance of particular genera/genus clusters was significantly altered among the various groups, with the EBV DNA-exacerbated arthritic group having the highest number of altered genera/genus cluster abundances. This group also had the highest number of cells co-expressing IL-17A, FOXP3, and IFNγ in the colons. Antimicrobial-cleared mice transplanted with fecal samples from EBV DNA-exacerbated arthritic mice showed a higher incidence and enhanced severity of RA compared to those transplanted with fecal samples from water or collagen-treated mice. IMPORTANCE Epstein-Barr virus (EBV) DNA alters the composition and diversity of the gut microbiota in a rheumatoid arthritis (RA) mouse model. These induced changes are associated with enhanced severity of symptoms. This better understanding of the various factors involved in the development of RA will possibly help in creating individualized treatments for RA patients including target mediators triggered by viral DNA. Given that a large swathe of the population harbors EBV, a significant proportion of subjects with arthritis may benefit from possible approaches that target EBV or mediators triggered by this virus.

Understanding Age-Related Longitudinal Dynamics in Abundance and Diversity of Dominant Culturable Gut Lactic Acid Bacteria in Pastured Goats

Understanding gut lactic acid bacteria (LAB) in healthy hosts is an important first step in selecting potential probiotic species. To understand the dynamics of LAB in healthy goats, a cohort of thirty-seven healthy new-born goat kids was studied over a ten-month period. Total LAB was quantified using SYBR green qPCR. Seven hundred LAB isolates were characterized using microscopy, M13 RAPD genotyping and 16S rDNA sequencing. The highest and lowest LAB counts were detected at one week and ten months of age, respectively. Diverse LAB species were detected, whose identity and prevalence varied with age. The main isolates belonged to Limosilactobacillus reuteri, Limosilactibacillus fermentum, Lactobacillus johnsonni, Ligilactobacillus murinus, Ligilactobacillus salivarius, Limosilactobacillus mucosae, Lactiplantibacillus plantarum, Ligilactobacillus agilis, Lactobacillus acidophilus/amyolovolus, Pediococcus spp. and Enterococcus spp. Uniquely, L. reuteri and Pediococcus spp. were most common in pre- and peri-weaned goats, while Lactobacillus mucosae and Enterococcus spp. were predominant in goats one month and older. Based on RAPD genotyping, L. reuteri had the highest genotypic diversity, with age being a factor on the genotypes detected. This data may be relevant in the selection of age-specific probiotics for goats. The findings may also have broader implications by highlighting age as a factor for consideration in probiotic bacteria selection in other animal hosts.

Bifidobacterium breve CBT BR3 is effective at relieving intestinal inflammation by augmenting goblet cell regeneration

BACKGROUND AND AIM

Bifidobacterium breve was the first bacteria isolated in the feces of healthy infants and is a dominant species in the guts of breast-fed infants. Some strains of B. breve have been shown to be effective at relieving intestinal inflammation, but the modes of action have yet to be elucidated. In this study, we investigated the mechanisms of action of B. breve CBT BR3 isolated from South Korean infant feces in relieving colitis in vitro and in vivo.

METHODS

Colitis was induced in mice with dextran sodium sulfate (DSS) and dinitrobenzene sulfonic acid (DNBS). Quantitative reverse-transcription polymerase chain reaction, in vitro FITC-dextran flux permeability assay, and aryl hydrocarbon receptor (AhR) luciferase assay are performed using Caco-2 cells and HT29-Lucia™ AhR cells.

RESULTS

B. breve CBT BR3 was orally administered. B. breve CBT BR3 improved colitis symptoms in both DSS- and DNBS-induced colitis models. B. breve CBT BR3 increased the number of goblet cells per crypt. B. breve increased the mRNA expressions of Notch, Spdef, Muc5, and Il22. The mRNA expressions of Occludin, which encodes a membrane tight-junction protein, and Foxo3, which encodes a protein related to butyrate metabolism, were also increased in the DSS- and DNBS-induced colitis models. B. breve CBT BR3 protected inflammation-induced epithelial cell permeability and improved goblet cell function by inducing aryl hydrocarbon receptor in vitro.

CONCLUSIONS

These results indicate that B. breve CBT BR3 is effective at relieving intestinal inflammation by augmenting goblet cell regeneration.

An Overview of the Use and Applications of Limosilactobacillus fermentum in Broiler Chickens

The implementation of government regulations on antibiotic use, along with the public's concern for drug resistance, has strengthened interest in developing alternatives not only aimed at preserving animal production but also at reducing the effects of pathogenic infections. Probiotics, in particular, are considered microorganisms that induce health benefits in the host after consumption of adequate amounts; they have been established as a potential strategy for improving growth, especially by stimulating intestinal homeostasis. Probiotics are commonly associated with lactic acid bacteria, and Limosilactobacillus fermentum is a well-studied species recognized for its favorable characteristics, including adhesion to epithelial cells, production of antimicrobial compounds, and activation of receptors that prompt the transcription of immune-associated genes. Recently, this species has been used in animal production. Different studies have shown that the application of L. fermentum strains not only improves the intestinal ecosystem but also reduces the effects caused by potentially pathogenic microorganisms. These studies have also revealed key insights into the mechanisms behind the actions exerted by this probiotic. In this manuscript, we aim to provide a concise overview of the effects of L. fermentum administration on broiler chicken health and performance.

Probiotic supplementation during antibiotic treatment is unjustified in maintaining the gut microbiome diversity: a systematic review and meta-analysis

BACKGROUND

Probiotics are often used to prevent antibiotic-induced low-diversity dysbiosis, however their effect is not yet sufficiently summarized in this regard. We aimed to investigate the effects of concurrent probiotic supplementation on gut microbiome composition during antibiotic therapy.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials reporting the differences in gut microbiome diversity between patients on antibiotic therapy with and without concomitant probiotic supplementation. The systematic search was performed in three databases (MEDLINE (via PubMed), Embase, and Cochrane Central Register of Controlled Trials (CENTRAL)) without filters on 15 October 2021. A random-effects model was used to estimate pooled mean differences (MD) with 95% confidence intervals (CI). This review was registered on PROSPERO (CRD42021282983).

RESULTS

Of 11,769 identified articles, 15 were eligible in the systematic review and 5 in the meta-analyses. Quantitative data synthesis for Shannon (MD = 0.23, 95% CI: [(-)0.06-0.51]), Chao1 (MD = 11.59 [(-)18.42-41.60]) and observed OTUs (operational taxonomic unit) (MD = 17.15 [(-)9.43-43.73]) diversity indices revealed no significant difference between probiotic supplemented and control groups. Lacking data prevented meta-analyzing other diversity indices; however, most of the included studies reported no difference in the other reported α- and ß-diversity indices between the groups. Changes in the taxonomic composition varied across the eligible studies but tended to be similar in both groups. However, they showed a potential tendency to restore baseline levels in both groups after 3-8 weeks. This is the first meta-analysis and the most comprehensive review of the topic to date using high quality methods. The limited number of studies and low sample sizes are the main limitations of our study. Moreover, there was high variability across the studies regarding the indication of antibiotic therapy and the type, dose, and duration of antimicrobials and probiotics.

CONCLUSIONS

Our results showed that probiotic supplementation during antibiotic therapy was not found to be influential on gut microbiome diversity indices. Defining appropriate microbiome diversity indices, their standard ranges, and their clinical relevance would be crucial.

Effects of isolation and confinement on gastrointestinal microbiota-a systematic review

Purpose

The gastrointestinal (GI) microbiota is a complex and dynamic ecosystem whose composition and function are influenced by many internal and external factors. Overall, the individual GI microbiota composition appears to be rather stable but can be influenced by extreme shifts in environmental exposures. To date, there is no systematic literature review that examines the effects of extreme environmental conditions, such as strict isolation and confinement, on the GI microbiota.

Methods

We conducted a systematic review to examine the effects of isolated and confined environments on the human GI microbiota. The literature search was conducted according to PRISMA criteria using PubMed, Web of Science and Cochrane Library. Relevant studies were identified based on exposure to isolated and confined environments, generally being also antigen-limited, for a minimum of 28 days and classified according to the microbiota analysis method (cultivation- or molecular based approaches) and the isolation habitat (space, space- or microgravity simulation such as MARS-500 or natural isolation such as Antarctica). Microbial shifts in abundance, alpha diversity and community structure in response to isolation were assessed.

Results

Regardless of the study habitat, inconsistent shifts in abundance of 40 different genera, mainly in the phylum Bacillota (formerly Firmicutes) were reported. Overall, the heterogeneity of studies was high. Reducing heterogeneity was neither possible by differentiating the microbiota analysis methods nor by subgrouping according to the isolation habitat. Alpha diversity evolved non-specifically, whereas the microbial community structure remained dissimilar despite partial convergence. The GI ecosystem returned to baseline levels following exposure, showing resilience irrespective of the experiment length.

Conclusion

An isolated and confined environment has a considerable impact on the GI microbiota composition in terms of diversity and relative abundances of dominant taxa. However, due to a limited number of studies with rather small sample sizes, it is important to approach an in-depth conclusion with caution, and results should be considered as a preliminary trend. The risk of dysbiosis and associated diseases should be considered when planning future projects in extreme environments.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022357589.

Bifidobacterium longum LBUX23 Isolated from Feces of a Newborn; Potential Probiotic Properties and Genomic Characterization

Bifidobacterium longum is considered a microorganism with probiotic potential, which has been extensively studied, but these probiotic effects are strain dependent. This work aims to characterize the probiotic potential, based on the biochemical and genomic functionality, of B. longum LBUX23, isolated from neonates' feces. B. longum LBUX23 contains one circular genome of 2,287,838 bp with a G+C content of 60.05%, no plasmids, no CRISPR-Cas operon, possesses 56 tRNAs, 9 rRNAs, 1 tmRNA and 1776 coding sequences (CDSs). It has chromosomally encoded resistance genes to ampicillin and dicloxacillin, non-hemolytic activity, and moderate inhibition of Escherichia coli ATCC 25922 and to some emergent pathogen's clinical strains. B. longum LBUX23 was able to utilize lactose, sucrose, fructooligosaccharides (FOS), and lactulose. The maximum peak of bacterial growth was observed in sucrose and FOS at 6 h; in lactose and lactulose, it was shown at 8 h. B. longum LBUX23 can survive in gastrointestinal conditions (pH 4 to 7). A decrease in survival (96.5 and 93.8%) was observed at pH 3 and 3.5 during 120 min. argC, argH, and dapA genes could be involved in this tolerance. B. longum LBUX23 can also survive under primary and secondary glyco- or tauro-conjugated bile salts, and a mixture of bile salts due to the high extracellular bile salt hydrolase (BSH) activity (67.3 %), in taurocholic acid followed by taurodeoxycholic acid (48.5%), glycocholic acid (47.1%), oxgall (44.3%), and glycodeoxycholic acid (29.7%) probably due to the presence of the cbh and gnlE genes which form an operon (start: 119573 and end: 123812). Low BSH activity was determined intracellularly (<7%), particularly in glycocholic acid; no intracellular activity was shown. B. longum LBUX23 showed antioxidant effects in DPPH radical, mainly in intact cells (27.4%). In the case of hydroxyl radical scavenging capacity, cell debris showed the highest reduction (72.5%). In the cell-free extract, superoxide anion radical scavenging capacity was higher (90.5%). The genome of B. longum LBUX23 contains PNPOx, AhpC, Bcp, trxA, and trxB genes, which could be involved in this activity. Regarding adherence, it showed adherence up to 5% to Caco-2 cells. B. longum LBUX23 showed in vitro potential probiotic properties, mainly in BSH activity and antioxidant capacity, which indicates that it could be a good candidate for antioxidant or anti-cholesterol tests using in vivo models.

The neuromodulatory effects of flavonoids and gut Microbiota through the gut-brain axis

Recent investigations show that dietary consumption of flavonoids could potentially confer neuroprotective effects through a variety of direct and indirect mechanisms. Numerous flavonoids have been shown to cross the BBB and accumulate within the central nervous system (CNS). Some of these compounds purportedly counteract the accumulation and deleterious effects of reactive oxygen species, fostering neuronal survival and proliferation by inhibiting neuroinflammatory and oxidative stress responses. Moreover, several studies suggest that gut microbiota may participate in regulating brain function and host behavior through the production and modulation of bioactive metabolites. Flavonoids may shape gut microbiota composition by acting as carbon substrates to promote the growth of beneficial bacteria that produce these neuroprotective metabolites, consequently antagonizing or suppressing potential pathogens. By influencing the microbiota-gut-brain axis through this selection process, flavonoids may indirectly improve brain health. This review examines the current state of research into the relationship between bioactive flavonoids, gut microbiota, and the gut-brain axis.

Extracellular vesicles of the Gram-positive gut symbiont Bifidobacterium longum induce immune-modulatory, anti-inflammatory effects

The gut microbiota is now well known to affect the host's immune system. One way of bacterial communication with host cells is via the secretion of vesicles, small membrane structures containing various cargo. Research on vesicles secreted by Gram-positive gut bacteria, their mechanisms of interaction with the host and their immune-modulatory effects are still relatively scarce. Here we characterized the size, protein content, and immune-modulatory effects of extracellular vesicles (EVs) secreted by a newly sequenced Gram-positive human gut symbiont strain - Bifidobacterium longum AO44. We found that B. longum EVs exert anti-inflammatory effects, inducing IL-10 secretion from both splenocytes and dendritic cells (DC)-CD4+ T cells co-cultures. Furthermore, the EVs protein content showed enrichment in ABC transporters, quorum sensing proteins, and extracellular solute-binding proteins, which were previously shown to have a prominent function in the anti-inflammatory effect of other strains of B. longum. This study underlines the importance of bacterial vesicles in facilitating the gut bacterial immune-modulatory effects on the host and sheds light on bacterial vesicles as future therapeutics.

Heat-treated foxtail millet protein delayed the development of pre-diabetes to diabetes in mice by altering gut microbiota and metabolomic profiles

Millet protein has gained much attention for its beneficial effects in mitigating metabolic diseases. However, most individuals pass through a prediabetic phase before developing full-blown diabetes, and whether millet protein has hypoglycemic effects on prediabetic mice remains unclear. In the present study, heat-treated foxtail millet protein (HMP) supplementation significantly decreased fasting blood glucose and serum insulin levels, alleviated insulin resistance, and improved impaired glucose tolerance in prediabetic mice. In addition, HMP altered the intestinal flora composition, as evidenced by the reduction in the abundance of Dubosiella and Marvinbryantia and the increase in the content of Lactobacillus, Bifidobacterium, and norank_f_Erysipelotrichaceae. Moreover, HMP supplementation dramatically regulated the levels of serum metabolites (i.e., LysoPCs, 11,14,17-eicosatrienoic acid, and sphingosine) and related metabolic pathways, such as sphingolipid metabolism and pantothenate and CoA biosynthesis. In conclusion, the improvement of gut microbiota and serum metabolic profiles was related to the hypoglycemic potential of HMP in prediabetes.

Terminalia bellirica ethanol extract ameliorates nonalcoholic fatty liver disease in mice by amending the intestinal microbiota and faecal metabolites

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia bellirica (Gaertn.) Roxb. (TB) is a traditional Tibetan medicine used to treat hepatobiliary diseases. However, modern pharmacological evidence of the activities and potential mechanisms of TB against nonalcoholic fatty liver disease (NAFLD) are still unknown.

AIM OF THE STUDY

This study aimed to evaluate the anti-NAFLD effect of ethanol extract of TB (ETB) and investigate whether its ameliorative effects are associated with the regulation of intestinal microecology.

MATERIALS AND METHODS

In this study, the curative effects of ETB on NAFLD were evaluated in mice fed a choline-deficient, L-amino acid defined, high fat diet (CDAHFD). Biochemical markers and hepatic histological alterations were detected. Gut microbiota and faecal metabolites were analyzed by 16S rRNA gene sequencing and liquid chromatograph mass spectrometer (LC‒MS) profiling.

RESULTS

The results showed that oral treatment with middle- and high-dose ETB significantly improved features of NAFLD, reducing the levels of TG, LDL-C, ALT and AST, and increasing the level of HDL-C. Liver histopathologic examination demonstrated that ETB attenuated lipid accumulation and hepatocellular necrosis. ETB treatment restored the structural disturbances of gut microbiota induced by CDAHFD, reduced the levels of Intestinimonas, Lachnoclostridium, and Lachnospirace-ae_FCS020_group, and increased Akkermansia and Bifidobacterium. Moreover, untargeted metabolomics analysis revealed that ETB could restore the disrupted taurine and hypotaurine metabolism, glycine, serine and threonine metabolism, and glutathione metabolism of the intestinal bacterial community in NAFLD mice.

CONCLUSIONS

ETB was effective in ameliorating the NAFLD, possibly by remodelling the gut microbiota composition and modulating the faecal metabolism metabolites of the host, highlighting the potential of TB as a resource for the development of anti-NAFLD drugs.

Basal Diet Fed to Recipient Mice Was the Driving Factor for Colitis and Colon Tumorigenesis, despite Fecal Microbiota Transfer from Mice with Severe or Mild Disease

Consumption of the total Western diet (TWD) in mice has been shown to increase gut inflammation, promote colon tumorigenesis, and alter fecal microbiome composition when compared to mice fed a healthy diet, i.e., AIN93G (AIN). However, it is unclear whether the gut microbiome contributes directly to colitis-associated CRC in this model. The objective of this study was to determine whether dynamic fecal microbiota transfer (FMT) from donor mice fed either the AIN basal diet or the TWD would alter colitis symptoms or colitis-associated CRC in recipient mice, which were fed either the AIN diet or the TWD, using a 2 × 2 factorial experiment design. Time-matched FMT from the donor mice fed the TWD did not significantly enhance symptoms of colitis, colon epithelial inflammation, mucosal injury, or colon tumor burden in the recipient mice fed the AIN diet. Conversely, FMT from the AIN-fed donors did not impart a protective effect on the recipient mice fed the TWD. Likewise, the composition of fecal microbiomes of the recipient mice was also affected to a much greater extent by the diet they consumed than by the source of FMT. In summary, FMT from the donor mice fed either basal diet with differing colitis or tumor outcomes did not shift colitis symptoms or colon tumorigenesis in the recipient mice, regardless of the basal diet they consumed. These observations suggest that the gut microbiome may not contribute directly to the development of disease in this animal model.

The Role of Probiotics in Inflammation Associated with Major Surgery: A Narrative Review

Background: Gut microbiota is well-known for its ability to maintain intestinal homeostasis. However, the disruption of this homeostasis, known as dysbiosis, leads to multiple consequences, including local and systemic inflammation. Surgery-induced inflammation is a major concern for patients, as it leads to many infectious and non-infectious complications. Objective: The purpose of this review was to explore the role of probiotics and symbiotics in surgery-induced inflammation and to determine if their use is effective in combatting inflammation and its complications Methods and Materials: A literature search was conducted, and articles published only in English, until December 2022 were included. The results are reported in the form of a narrative review. Results: The perioperative use of probiotics and/or symbiotics results in lower risk of infectious complications, including reduced rates of surgical site infections, respiratory and urinary tract infections, shorter hospital stays, and fewer days of antibiotic administration. It also contributes to reducing non-infectious complications, as it mitigates systemic and local inflammation via maintenance of the intestinal barrier, improves intestinal mobility, and is associated with lower rates of postoperative pain and anastomotic leak. Conclusions: Restoring gut microbiota after disruptions caused by surgery may accelerate local healing processes, attenuate systemic inflammation, and may thus prove beneficial to certain populations.

Role of microbiota and microbiota-derived short-chain fatty acids in PDAC

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive lethal diseases among other cancer types. Gut microbiome and its metabolic regulation play a crucial role in PDAC. Metabolic regulation in the gut is a complex process that involves microbiome and microbiome-derived short-chain fatty acids (SCFAs). SCFAs regulate inflammation, as well as lipid and glucose metabolism, through different pathways. This review aims to summarize recent developments in PDAC in the context of gut and oral microbiota and their associations with short-chain fatty acid (SCFA). In addition to this, we discuss possible therapeutic applications using microbiota in PDAC.

Therapeutic Oral Application of Carvacrol Alleviates Acute Campylobacteriosis in Mice Harboring a Human Gut Microbiota

Human Campylobacter jejuni infections are rising globally. Since antibiotics are usually not indicated in acute campylobacteriosis, antibiotic-independent intervention measures are desirable. The phenolic compound carvacrol constitutes a promising candidate molecule given its antimicrobial and immune-modulatory features. To test the disease-alleviating effects of oral carvacrol treatment in acute murine campylobacteriosis, IL-10-/- mice harboring a human gut microbiota were perorally infected with C. jejuni and treated with carvacrol via the drinking water. Whereas C. jejuni stably established in the gastrointestinal tract of mice from the placebo cohort, carvacrol treatment resulted in lower pathogen loads in the small intestines on day 6 post infection. When compared to placebo, carvacrol ameliorated pathogen-induced symptoms including bloody diarrhea that was accompanied by less distinct histopathological and apoptotic cell responses in the colon. Furthermore, innate and adaptive immune cell numbers were lower in the colon of carvacrol- versus placebo-treated mice. Notably, carvacrol application dampened C. jejuni-induced secretion of pro-inflammatory mediators in intestinal, extra-intestinal and systemic organs to naive levels and furthermore, resulted in distinct shifts in the fecal microbiota composition. In conclusion, our preclinical placebo-controlled intervention study provides evidence that therapeutic carvacrol application constitutes a promising option to alleviate campylobacteriosis in the infected vertebrate host.

Gut Microbiota in Colorectal Cancer: Biological Role and Therapeutic Opportunities

Colorectal cancer (CRC) is the second-leading cause of cancer-related deaths worldwide. While CRC is thought to be an interplay between genetic and environmental factors, several lines of evidence suggest the involvement of gut microbiota in promoting inflammation and tumor progression. Gut microbiota refer to the ~40 trillion microorganisms that inhabit the human gut. Advances in next-generation sequencing technologies and metagenomics have provided new insights into the gut microbial ecology and have helped in linking gut microbiota to CRC. Many studies carried out in humans and animal models have emphasized the role of certain gut bacteria, such as Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, and colibactin-producing Escherichia coli, in the onset and progression of CRC. Metagenomic studies have opened up new avenues for the application of gut microbiota in the diagnosis, prevention, and treatment of CRC. This review article summarizes the role of gut microbiota in CRC development and its use as a biomarker to predict the disease and its potential therapeutic applications.

Dietary Complex Probiotic Supplementation Changed the Composition of Intestinal Short-Chain Fatty Acids and Improved the Average Daily Gain of Growing Pigs

At present, probiotics are being extensively evaluated for their efficacy as an alternative to antibiotics, and their safety in livestock production. In this study, 128 (Duroc, Yorkshire and Landrace) pigs with an average initial body weight of 28.38 ± 0.25 kg were allocated to four dietary treatments in a randomized complete-block design. There were eight pens per treatment, with four pigs per pen (two barrows and two gilts). Dietary treatments included: (1) control diet; (2) control diet + 0.05% complex probiotic; (3) control diet + 0.1% complex probiotic; (4) control diet + 0.2% complex probiotic. During the 28-day experimental period, the feeding of 0.1% complex probiotic in the diet increased body weight and average daily gain (p < 0.05). The addition of complex probiotics decreased total cholesterol and glucose concentrations in the blood (p < 0.01). Acetate concentrations in the blood increased from 0.1% complex probiotic in the diet (p < 0.05), while NH₃ and H₂S emissions in the feces decreased (p < 0.05) from 0.1% or 0.2% complex probiotic in the diet. In conclusion, dietary complex probiotic supplementation changed the composition of intestinal short-chain fatty acids and improved growth performance for growing pigs.

Fructooligosaccharides (FOS) differentially modifies the in vitro gut microbiota in an age-dependent manner

Introduction

Fructooligosaccharides (FOS) are well-known carbohydrates that promote healthy gut microbiota and have been previously demonstrated to enhance levels of Bifidobacterium and Lactobacillus. Its bifidogenic properties are associated with positive health outcomes such as reduced obesity and anti-inflammatory properties, and, therefore, is in use as a prebiotic supplement to support healthy gut microbiota. However, the gut microbiota changes with age, which may lead to differential responses to treatments with prebiotics and other dietary supplements.

Methods

To address this concern, we implemented a 24-h in vitro culturing method to determine whether FOS treatment in three different adult age groups would have a differential effect. The age groups of interest ranged from 25 to 70 years and were split into young adults, adults, and older adults for the purposes of this analysis. Metagenomics and short-chain fatty acid analysis were performed to determine changes in the structure and function of the microbial communities.

Results

These analyses found that FOS created a bifidogenic response in all age groups, increased overall SCFA levels, decreased alpha diversity, and shifted the communities to be more similar in beta diversity metrics. However, the age groups differed in which taxa were most prevalent or most affected by FOS treatment.

Discussion

Overall, the results of this study demonstrate the positive effects of FOS on the gut microbiome, and importantly, how age may play a role in the effectiveness of this prebiotic.

Comparative analysis of scalp and gut microbiome in androgenetic alopecia: A Korean cross-sectional study

Androgenetic alopecia (AGA) is a non-scarring and progressive form of hair loss occurring in both men and women. Although genetic predisposition and sex steroid hormones are the main causes, many factors remain unknown, and various extrinsic factors can negatively affect the lifespan of hair. We investigated skin-gut axis microorganisms as potential exogenous factors causing AGA, through comparative analyses of the scalp and gut microbiome in individuals with and without AGA in a Korean cohort. Using 16S rRNA gene sequencing, we characterized the scalp and gut microbiomes of 141 individuals divided into groups by sex and presence of AGA. Alpha diversity indices in the scalp microbiome were generally higher in individuals with AGA than in healthy controls. These indices showed a strong negative correlation with scalp-inhabitant bacteria (Cutibacterium and Staphylococcus), indicating that the appearance of non-inhabitant bacteria increases as hair loss progresses. No significant differences in diversity were observed between the gut microbiomes. However, bacterial functional differences, such as bile acid synthesis and bacterial invasion of epithelial cells, which are related to intestinal homeostasis, were observed. The networks of the scalp and gut microbiome were more complex and denser with higher values of the network topology statistic coefficient values (i.e., transitivity, density, and degree centrality) and more unique associations in individuals with AGA than in healthy controls. Our findings reveal a link between skin-gut microorganisms and AGA, indicating the former's potential involvement in the latter's development. Additionally, these results provide evidence for the development of cosmetics and therapeutics using microorganisms and metabolites involved in AGA.

Dietary Supplementation with Black Raspberries Altered the Gut Microbiome Composition in a Mouse Model of Colitis-Associated Colorectal Cancer, although with Differing Effects for a Healthy versus a Western Basal Diet

Black raspberries (BRB) are rich in anthocyanins with purported anti-inflammatory properties. However, it is not known whether dietary supplementation would ameliorate Western-diet enhanced gut inflammation and colon tumorigenesis. We employed a mouse model of colitis-associated colorectal cancer (CAC) to determine the effects of dietary supplementation with 5 to 10% (w/w) whole, freeze-dried BRB in male C57BL/6J mice fed either a standard healthy diet (AIN93G) or the total Western diet (TWD). In a pilot study, BRB suppressed colitis and colon tumorigenesis while also shifting the composition of the fecal microbiome in favor of taxa with purported health benefits, including Bifidobacterium pseudolongum. In a follow-up experiment using a 2 × 2 factorial design with AIN and TWD basal diets with and without 10% (w/w) BRB, supplementation with BRB reduced tumor multiplicity and increased colon length, irrespective of the basal diet, but it did not apparently affect colitis symptoms, colon inflammation or mucosal injury based on histopathological findings. However, BRB intake increased alpha diversity, altered beta diversity and changed the relative abundance of Erysipelotrichaceae, Bifidobacteriaceae, Streptococcaceae, Rikenellaceae, Ruminococcaceae and Akkermansiaceae, among others, of the fecal microbiome. Notably, changes in microbiome profiles were inconsistent with respect to the basal diet consumed. Overall, these studies provide equivocal evidence for in vivo anti-inflammatory effects of BRB on colitis and colon tumorigenesis; yet, BRB supplementation led to dynamic changes in the fecal microbiome composition over the course of disease development.

Walnut consumption and health outcomes with public health relevance-a systematic review of cohort studies and randomized controlled trials published from 2017 to present

CONTEXT

Considering the accumulation of recent studies investigating the health effects of walnut consumption, both including and beyond cardiovascular health effects, a systematic review of this literature to investigate the strength of the evidence is warranted.

OBJECTIVE

To investigate associations between walnut consumption and outcomes with public health relevance (specifically all-cause mortality, type 2 diabetes, CVD, metabolic syndrome, obesity, cancer, neurological and mental health, musculoskeletal, gastrointestinal, and maternal disorders) and the effect on associated disease risk markers, reported in studies published from 2017 to present.

DATA SOURCES

MEDLINE, FSTA, CENTRAL, and Scopus were searched from 1 January 2017 to 5 May 2021.

DATA EXTRACTION

Human studies (cohort studies and RCTs) ≥3 weeks in duration comparing consumption of walnuts (whole, pieces, or 100% butter) to a control and measuring associations with relevant public health outcomes and disease risk markers were assessed. Key study characteristics were extracted independently by 2 investigators using a standardized table. The quality of the studies was assessed using the Cochrane Risk-of-Bias tool 2.0 and the Newcastle-Ottawa Scale.

DATA ANALYSIS

Only 1 RCT was considered to be at low risk of bias for any of its outcomes. The cohort studies were considered to be of moderate or high quality. The results were synthesized using vote counting, based on the direction of effect. Thirty-three articles, 23 describing RCTs (walnut dose ∼10-99 g/day, 1,948 subjects) and 10 describing cohort studies (∼675,928 subjects), were included. Vote counting could be performed for the blood lipids, cardiovascular function, inflammation- and hemostatic-related factors, markers of glucose metabolism, and body weight and composition outcome groupings. The results are presented in effect direction plots. With respect to blood lipids, results from 8/8 RCTs favoured walnuts, in accordance with associations with a reduced risk of CVD suggested by cohort studies; results from 6/6 RCTs favoured control with respect to body weight and composition, although most of these effects were small. This was contrary to cohort study results suggesting small benefits of walnut consumption on body weight. There was no overall consistent direction of effect for cardiovascular function, markers of glucose metabolism, or inflammation- and hemostatic-related factors.

CONCLUSIONS

Evidence published since 2017 is consistent with previous research suggesting that walnut consumption improves lipid profiles and is associated with reduced CVD risk. Evidence is accumulating in other areas, such as cognitive health, although more research is needed to draw firm conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD4202122.

Microbial Modulation in Inflammatory Bowel Diseases

Gut dysbiosis is one of prominent features in inflammatory bowel diseases (IBDs) which are of an unknown etiology. Although the cause-and-effect relationship between IBD and gut dysbiosis remains to be elucidated, one area of research has focused on the management of IBD by modulating and correcting gut dysbiosis. The use of antibiotics, probiotics either with or without prebiotics, and fecal microbiota transplantation from healthy donors are representative methods for modulating the intestinal microbiota ecosystem. The gut microbiota is not a simple assembly of bacteria, fungi, and viruses, but a complex organ-like community system composed of numerous kinds of microorganisms. Thus, studies on specific changes in the gut microbiota depending on which treatment option is applied are very limited. Here, we review previous studies on microbial modulation as a therapeutic option for IBD and its significance in the pathogenesis of IBD.

The role and therapeutic potential of gut microbiome in severe burn

Severe burn is a serious acute trauma that can lead to significant complications such as sepsis, multiple organ failure, and high mortality worldwide. The gut microbiome, the largest microbial reservoir in the human body, plays a significant role in this pathogenic process. Intestinal dysbiosis and disruption of the intestinal mucosal barrier are common after severe burn, leading to bacterial translocation to the bloodstream and other organs of the body, which is associated with many subsequent severe complications. The progression of some intestinal diseases can be improved by modulating the composition of gut microbiota and the levels of its metabolites, which also provides a promising direction for post-burn treatment. In this article, we summarised the studies describing changes in the gut microbiome after severe burn, as well as changes in the function of the intestinal mucosal barrier. Additionally, we presented the potential and challenges of microbial therapy, which may provide microbial therapy strategies for severe burn.

The Role of Individually Selected Diets in Obese Women with PCOS-A Review

Polycystic ovarian syndrome (PCOS) is one of the most common heterogeneous endocrine and metabolic disorders in premenopausal women. It is a complex multifactorial disorder with strong epigenetic and environmental influences, including factors related to eating habits and lifestyle. There is a close relationship between obesity and PCOS. Weight gain and obesity are often clinical symptoms manifested by biochemical markers. Moreover, abdominal obesity in women with PCOS is involved in the development of inflammatory changes. A significant share of balanced therapies correcting the lifestyle of patients is suggested, e.g., with the implementation of appropriate diets to minimize exposure to inflammatory factors and prevent abnormal immune system stimulation. In the case of obese patients with PCOS, planning a diet program and supporting the motivation to change eating habits play an important role to lose weight and lower BMI. Probiotics/synbiotic supplementation may enhance weight loss during the diet program and additionally positively affect metabolic and inflammatory factors by improving the intestinal microbiome.

An observational investigation of the faical microbiota and metabonome of gastrostomy fed children, on blended and formula diets

Gastrostomy fed children traditionally have a Formulae diet (FD), which fulfills nutritional requirements; however, many families are adopting Blended diets (BD), which are what the whole family would eat. We undertook an observational investigation of the colonic microbiota and metabonome in a small group of gastrostomy fed children, who were either on an FD or BD, and compared, where possible to their siblings (17 FD, 28 BD, 19 HS). There was no increase in complications in tube blockage or infection rates, but a significant improvement in the prevalence of bowel problems, a reduction in medication and an increase in quality of life. Metataxonomic analysis showed that the FD group was significantly different to the Sibling group, and that families did not cluster together. Whole sample metabonomics showed no differences between groups; however, univariate analysis of biologically important metabolites did differ. Changing to a BD resulted in no increase in complications or risks, but improved the overall quality of life for the children and families.

Dietary xenobiotics, (poly)phenols and fibers: Exploring associations with gut microbiota in socially vulnerable individuals

Objectives

Although xenobiotics derived from food processing may cause modifications in the composition of the gut microbiota (GM) evidence is scarce. The aim of this study is to evaluate the impact of potential dietary carcinogens as heterocyclic amines (HAs), polycyclic aromatic hydrocarbons (PAHs), nitrates, nitrites, nitroso compounds and acrylamide, in combination to fibers (poly)phenols on the GM composition in a group of materially deprived subjects.

Study design

Transversal observational study in a sample of 19 subjects recipients of Red Cross food aid. Dietary information was recorded by means of 3 non-consecutive 24 h recalls. Questions focused on the type of cooking and the extent of cooking and roasting were included. Information on potential carcinogens was mainly obtained from the European Prospective Investigation into Cancer and Nutrition (EPIC) and Computerized Heterocyclic Amines Resource for Research in Epidemiology of Disease (CHARRED) Carcinogen Databases. Microbial composition was determined by 16S ribosomal RNA gene sequencing in fecal samples.

Results

Higher levels of Lachnospiraceae and Eggerthellaceae families were found in individuals consuming less than 50 ng/day of 2-amino-3,8 dimethylimidazo (4,5,f) quinoxaline (MeIQx) (considered as lower risk dose for colorectal adenoma) while those consuming more than 40 ng/day of 2-amino-1-methyl-6-phenylimidazo (4,5,b) pyridine (PhIP) (higher risk for colorectal adenoma) showed lower relative abundance of Muribaculaceae and greater presence of Streptococcaceae and Eubacterium coprostanoligenes group.

Conclusion

The associations identified between diet and processing by-products on GM in this study could be used as potential targets for the designing of dietary interventions tailored to this collective.

Does the Gut Microbial Metabolome Really Matter? The Connection between GUT Metabolome and Neurological Disorders

Herein we gathered updated knowledge regarding the alterations of gut microbiota (dysbiosis) and its correlation with human neurodegenerative and brain-related diseases, e.g., Alzheimer’s and Parkinson’s. This review underlines the importance of gut-derived metabolites and gut metabolic status as the main players in gut-brain crosstalk and their implications on the severity of neural conditions. Scientific evidence indicates that the administration of probiotic bacteria exerts beneficial and protective effects as reduced systemic inflammation, neuroinflammation, and inhibited neurodegeneration. The experimental results performed on animals, but also human clinical trials, show the importance of designing a novel microbiota-based probiotic dietary supplementation with the aim to prevent or ease the symptoms of Alzheimer’s and Parkinson’s diseases or other forms of dementia or neurodegeneration.

IHNV Infection Induces Strong Mucosal Immunity and Changes of Microbiota in Trout Intestine

The fish intestinal mucosa is among the main sites through which environmental microorganisms interact with the host. Therefore, this tissue not only constitutes the first line of defense against pathogenic microorganisms but also plays a crucial role in commensal colonization. The interaction between the mucosal immune system, commensal microbiota, and viral pathogens has been extensively described in the mammalian intestine. However, very few studies have characterized these interactions in early vertebrates such as teleosts. In this study, rainbow trout (Oncorhynchus mykiss) was infected with infectious hematopoietic necrosis virus (IHNV) via a recently developed immersion method to explore the effects of viral infection on gut immunity and microbial community structure. IHNV successfully invaded the gut mucosa of trout, resulting in severe tissue damage, inflammation, and an increase in gut mucus. Moreover, viral infection triggered a strong innate and adaptive immune response in the gut, and RNA−seq analysis indicated that both antiviral and antibacterial immune pathways were induced, suggesting that the viral infection was accompanied by secondary bacterial infection. Furthermore, 16S rRNA sequencing also revealed that IHNV infection induced severe dysbiosis, which was characterized by large increases in the abundance of Bacteroidetes and pathobiont proliferation. Moreover, the fish that survived viral infection exhibited a reversal of tissue damage and inflammation, and their microbiome was restored to its pre−infection state. Our findings thus demonstrated that the relationships between the microbiota and gut immune system are highly sensitive to the physiological changes triggered by viral infection. Therefore, opportunistic bacterial infection must also be considered when developing strategies to control viral infection.

The effects of grape seed proanthocyanidins in cafeteria diet-induced obese Fischer 344 rats are influenced by faecal microbiota in a photoperiod dependent manner

Polyphenols are of high interest due to their beneficial health effects, including anti-obesity properties. The gut microbiota may play an important role in polyphenol-mediated effects as these bacteria are significantly involved in the metabolism of polyphenols. Moreover, seasonal rhythms have been demonstrated to influence both the gut microbiota composition and polyphenol bioavailability. Thus, the goal of this study was to evaluate the impact of photoperiods and microbiota on polyphenol functionality in an obesogenic context. Towards this aim, cafeteria diet-fed Fischer 344 rats were housed under three different photoperiod conditions (L6: 6 h of light, L12: 12 h of light and L18: 18 h of light) for 9 weeks. During the last 4 weeks of the experiment, rats were daily administered with an oral dose of a grape seed proanthocyanidin extract (GSPE) (25 mg per kg body weight). Additionally, rats treated with GSPE and an antibiotic cocktail (ABX) in their drinking water were included for a better understanding of the gut microbiota role in GSPE functionality. Vehicle and non-ABX treated rats were included as controls. GSPE decreased body weight gain and fat depots only under L18 conditions. Interestingly, the gut microbiota composition was strongly altered in this photoperiod. GSPE + ABX-treated rats gained significantly less body weight compared to the rats of the rest of the treatments under L18 conditions. These results suggest that GSPE functionality is modulated by the gut microbiota in a photoperiod dependent manner. These novel findings corroborate seasonal rhythms as key factors that must be taken into account when investigating the effects of polyphenols in the treatment or prevention of chronic diseases.

Effect of Fructooligosaccharides Supplementation on the Gut Microbiota in Human: A Systematic Review and Meta-Analysis

Background: Numerous studies have investigated the effects of the supplementation of fructooligosaccharides (FOS) on the number of bacteria in the gut that are good for health, but the results have been inconsistent. Additionally, due to its high fermentability, supplementation of FOS may be associated with adverse gastrointestinal symptoms such as bloating and flatulence. Therefore, we assessed the effects of FOS interventions on the composition of gut microbiota and gastrointestinal symptoms in a systematic review and meta-analysis. Design: All randomized controlled trials published before 10 July 2022 that investigated the effects of FOS supplementation on the human gut microbiota composition and gastrointestinal symptoms and met the selection criteria were included in this study. Using fixed or random-effects models, the means and standard deviations of the differences between the two groups before and after the intervention were combined into weighted mean differences using 95% confidence intervals (CIs). Results: Eight studies containing 213 FOS supplements and 175 controls remained in this meta-analysis. Bifidobacterium spp. counts significantly increased during FOS ingestion (0.579, 95% CI: 0.444−0.714) in comparison with that of the control group. Subgroup analysis showed greater variation in Bifidobacterium spp. in adults (0.861, 95% CI: 0.614−1.108) than in infants (0.458, 95% CI: 0.297−0.619). The increase in Bifidobacterium spp. counts were greater in the group with an intervention duration greater than 4 weeks (0.841, 95% CI: 0.436−1.247) than an intervention time less than or equal to four weeks (0.532, 95% CI: 0.370−0.694), and in the group with intervention doses > 5 g (1.116, 95% CI: 0.685−1.546) the counts were higher than those with doses ≤ 5 g (0.521, 95% CI: 0.379−0.663). No differences in effect were found between FOS intervention and comparators in regard to the abundance of other prespecified bacteria or adverse gastrointestinal symptoms. Conclusions: This is the first meta-analysis to explore the effect of FOS on gut microbiota and to evaluate the adverse effects of FOS intake on the gastrointestinal tract. FOS supplementation could increase the number of colonic Bifidobacterium spp. while higher dose (7.5−15 g/d) and longer duration (>4 weeks) showed more distinct effects and was well tolerated.

Protective Effect of Bilberry Anthocyanin Extracts on Dextran Sulfate Sodium-Induced Intestinal Damage in Drosophila melanogaster

Inflammatory bowel disease (IBD) is a chronic recurrent disease that can be controlled by various natural extracts. Anthocyanins (ANCs) from bilberry have significant antioxidant capacity and are widely used as food colors and antioxidants. In this study, we investigated the protective effects of bilberry anthocyanin extracts (BANCs) against dextran sulphate sodium (DSS)-induced intestinal inflammation in a Drosophila melanogaster (D. melanogaster) model, and the effects on the lifespan, antioxidant capacity, intestinal characteristics, and microbiome and gene expression profiles were analyzed to elucidate the underlying biological mechanisms. In DSS-induced normal and axenic D. melanogaster, BANCs significantly increased the survival rate, maintained the intestinal morphology and integrity, and reduced the number of dead intestinal epithelial cells and the ROS level of these cells. BANC supplementation had no significant effect on the intestinal microflora of DSS-induced D. melanogaster, as demonstrated by a 16S rDNA analysis, but improved the antioxidant capacity by activating the relative gene expression of NRF2 signaling pathways in the intestine of D. melanogaster with DSS-induced inflammation. Therefore, the results demonstrate that BANCs effectively alleviate intestinal inflammatory injury induced by DSS and improve the antioxidant capacity of D. melanogaster by modulating NRF2 signaling pathways, and could thus promote the application of BANCs as functional foods.

Fecal Microbiota Transplantation During Lactation Programs the Metabolism of Adult Wistar Rats in a Sex-specific Way

BACKGROUND

The intestinal microbiota is involved in many physiological processes. However, the effects of microbiota in metabolic programming still unknow. We evaluated whether the transplantation of fecal microbiota during early life can program health or disease during adulthood in a model of lean and obese male and female Wistar rats.

METHODS

Parental obesity were induced using a small litter (SL, 3 pups/dam) model. At 90 d old, normal litter (NL, 9 pups/dam) and SL males and females (parents) from different litters were mated: NL male vs. NL female; SL male vs. SL female. After birth, male and female offspring rats were also standardized in normal litters or small litters . From the 10^th until 25^th d of life, the NL and SL male and female offspring received via gavage of a solution containing the diluted feces of the opposite dam (fecal microbiota, M) or saline solution (S). At 90 d of age, biometric and biochemical parameters were assessed.

RESULTS

NLM male rats transplanted with obese microbiota showed increased body weight, and fat pad deposition, hyperinsulinemia, glucose intolerance and dyslipidemia. SLM male rats transplanted with lean microbiota had decreased retroperitoneal and mesenteric fat, triglycerides and VLDL levels and improvement of glucose tolerance. Despite SLM female rats showed higher visceral fat, microbiota transplantation in female rats caused no changes in these parameters compared with control groups.

CONCLUSION

Fecal microbiota transplantation during lactation induces long-term effects on the metabolism of male Wistar rats. However, female rats were resistant to metabolic alterations caused by the treatment.

Genome-wide siRNA screening reveals several host receptors for the binding of human gut commensal Bifidobacterium bifidum

Bifidobacterium spp. are abundant gut commensals, especially in breast-fed infants. Bifidobacteria are associated with many health-promoting effects including maintenance of epithelial barrier and integrity as well as immunomodulation. However, the protective mechanisms of bifidobacteria on intestinal epithelium at molecular level are poorly understood. In this study, we developed a high-throughput in vitro screening assay to explore binding receptors of intestinal epithelial cells for Bifidobacterium bifidum. Short interfering RNAs (siRNA) were used to silence expression of each gene in the Caco-2 cell line one by one. The screen yielded four cell surface proteins, SERPINB3, LGICZ1, PKD1 and PAQR6, which were identified as potential receptors as the siRNA knock-down of their expression decreased adhesion of B. bifidum to the cell line repeatedly during the three rounds of siRNA screening. Furthermore, blocking of these host cell proteins by specific antibodies decreased the binding of B. bifidum significantly to Caco-2 and HT29 cell lines. All these molecules are located on the surface of epithelial cells and three out of four, SERPINB3, PKD1 and PAQR6, are involved in the regulation of cellular processes related to proliferation, differentiation and apoptosis as well as inflammation and immunity. Our results provide leads to the first steps in the mechanistic cascade of B. bifidum-host interactions leading to regulatory effects in the epithelium and may partly explain how this commensal bacterium is able to promote intestinal homeostasis.

Effect of gut microbiota in the colorectal cancer and potential target therapy

The symbiotic interaction between gut microbiota and the digestive tract is an important factor in maintaining the intestinal environment balance. Colorectal cancer (CRC) is a complex disease involving the interaction between tumour cells and a large number of microorganisms. The microbiota is involved in the occurrence, development and prognosis of colorectal cancer. Several microbiota species have been studied, such as Fusobacterium nucleatum (F. nucleatum), Enterotoxigenic Bacteroides fragilis (ETBF), Streptococcus bovis (S. bovis), Lactobacillus, and Bifidobacterium. Studies about the interaction between microbiota and CRC were retrieved from Embase, PubMed, Ovid and Web of Science up to 21 Oct 2021. This review expounded on the effect of microbiota on CRC, especially the dysregulation of bacteria and carcinogenicity. The methods of gut microbiota modifications representing novel prognostic markers and innovative therapeutic strategies were also described.

Human Milk Oligosaccharides and Lactose Differentially Affect Infant Gut Microbiota and Intestinal Barrier In Vitro

Background: The infant gut microbiota establishes during a critical window of opportunity when metabolic and immune functions are highly susceptible to environmental changes, such as diet. Human milk oligosaccharides (HMOs) for instance are suggested to be beneficial for infant health and gut microbiota. Infant formulas supplemented with the HMOs 2′-fucosyllactose (2′-FL) and lacto-N-neotetraose (LNnT) reduce infant morbidity and medication use and promote beneficial bacteria in the infant gut ecosystem. To further improve infant formula and achieve closer proximity to human milk composition, more complex HMO mixtures could be added. However, we currently lack knowledge about their effects on infants’ gut ecosystems. Method: We assessed the effect of lactose, 2′-FL, 2′-FL + LNnT, and a mixture of six HMOs (HMO6: consisting of 2′-FL, LNnT, difucosyllactose, lacto-N-tetraose, 3′- and 6′-sialyllactose) on infant gut microbiota and intestinal barrier integrity using a combination of in vitro models to mimic the microbial ecosystem (baby M-SHIME^®) and the intestinal epithelium (Caco-2/HT29-MTX co-culture). Results: All the tested products had bifidogenic potential and increased SCFA levels; however, only the HMOs’ fermented media protected against inflammatory intestinal barrier disruption. 2′-FL/LNnT and HMO6 promoted the highest diversification of OTUs within the Bifidobactericeae family, whereas beneficial butyrate-producers were specifically enriched by HMO6. Conclusion: These results suggest that increased complexity in HMO mixture composition may benefit the infant gut ecosystem, promoting different bifidobacterial communities and protecting the gut barrier against pro-inflammatory imbalances.

Multi-Omic Analyses Reveal Bifidogenic Effect and Metabolomic Shifts in Healthy Human Cohort Supplemented With a Prebiotic Dietary Fiber Blend

Dietary fiber, a nutrient derived mainly from whole grains, vegetables, fruits, and legumes, is known to confer a number of health benefits, yet most Americans consume less than half of the daily recommended amount. Convenience and affordability are key factors determining the ability of individuals to incorporate fiber-rich foods into their diet, and many Americans struggle to access, afford, and prepare foods rich in fiber. The objective of this clinical study was to test the changes in microbial community composition, human metabolomics, and general health markers of a convenient, easy to use prebiotic supplement in generally healthy young participants consuming a diet low in fiber. Twenty healthy adults participated in this randomized, placebo-controlled, double-blind, crossover study which was registered at clinicaltrials.gov as NCT03785860. During the study participants consumed 12 g of a prebiotic fiber supplement and 12 g of placebo daily as a powder mixed with water as part of their habitual diet in randomized order for 4 weeks, with a 4-week washout between treatment arms. Fecal microbial DNA was extracted and sequenced by shallow shotgun sequencing on an Illumina NovaSeq. Plasma metabolites were detected using liquid chromatography–mass spectrometry with untargeted analysis. The phylum Actinobacteria, genus Bifidobacterium, and several Bifidobacterium species (B. bifidum, B. adolescentis, B. breve, B. catenulatum, and B. longum) significantly increased after prebiotic supplementation when compared to the placebo. The abundance of genes associated with the utilization of the prebiotic fiber ingredients (sacA, xfp, xpk) and the production of acetate (poxB, ackA) significantly changed with prebiotic supplementation. Additionally, the abundance of genes associated with the prebiotic utilization (xfp, xpk), acetate production (ackA), and choline to betaine oxidation (gbsB) were significantly correlated with changes in the abundance of the genus Bifidobacterium in the prebiotic group. Plasma concentrations of the bacterially produced metabolite indolepropionate significantly increased. The results of this study demonstrate that an easy to consume, low dose (12 g) of a prebiotic powder taken daily increases the abundance of beneficial bifidobacteria and the production of health-promoting bacteria-derived metabolites in healthy individuals with a habitual low-fiber diet.

The effect of a probiotic on gastrointestinal symptoms due to menstruation in healthy adult women on oral contraceptives: randomized, double-blind, placebo-controlled trial protocol

Introduction

For many women, uncomfortable and stressful symptoms accompany the menstrual cycle each month, sometimes in a debilitating manner. Previous studies have reported that gastrointestinal symptoms in healthy women significantly differ by the day of the menstrual cycle, but few studies have assessed interventions intended to minimize these symptoms. Probiotics supplements have been shown to attenuate gastrointestinal symptom severity as well as self-reported feelings of stress in various populations. This study evaluates the effect of a probiotic on abdominal pain and gastrointestinal symptoms in healthy women who take an oral contraceptive, have regular menses, and typically experience these symptoms during menstruation with the primary aim being change in abdominal pain intensity related to the menstrual cycle with probiotic versus placebo supplementation.

Methods and analysis

In this randomized, double-blind, placebo-controlled parallel study, participants will receive either a probiotic or placebo supplement. Participants will begin answering questionnaires approximately 7 days before the start of menstruation (i.e., active bleeding), and 3 days later, they will begin consuming the study supplement for 8 weeks. The questionnaires administered will collect data about abdominal pain severity (primary outcome) and duration related to the menstrual cycle, digestive health, dietary intake, stress, and digestion-associated quality-of-life. A subgroup of women will provide weekly vaginal swabs and stool samples to examine the effect of the probiotic supplement on microbiota composition and diversity for exploratory purposes. Two-sided tests using a linear model and a type I error rate of α = 0.05 will be employed to test all hypotheses. Continuous variables will be presented as means with standard errors and categorical variables, as counts or proportions.

Ethics and dissemination

This study was reviewed and approved by the University of Florida Institutional Review Board 01. Written informed consent will be obtained from all participants prior to any study activities. Study findings will be disseminated at scientific conferences and publication in the trial registry or in a peer-reviewed journal. Any protocol amendments will be reported in the final manuscript of this study.

Trial registration

ClinicalTrials.gov NCT04457401. Registered prospectively on 07 July 2020. The trial was completed in December of 2021.

Protocol version

V4.0 (11-04-2020)

Trial status

Currently recruiting. Recruitment began in November 2020 and extend until December 2021.

Effect of Probiotics Therapy on Nonalcoholic Fatty Liver Disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in the world. The pathogenesis of NAFLD is complex and multifactorial. Clinical studies have shown that alterations in the gut microbiota play a key role in NAFLD. The purpose of this study was to analyze the effect of probiotic supplementation on the treatment of NAFLD patients based on various indicators.

METHODS

We conducted a meta-analysis investigating the relationship between NAFLD and probiotic supplementation. Embase, PubMed, and Web of Science databases were searched by computer, and then, eligible studies were identified. Finally, a total of high-quality randomized controlled trials were selected involving 1403 participants. Meta-analysis was performed using the RevMan 5.3 software which was systematically searched for works published through Dec. 1, 2021, in the present study.

RESULTS

The meta-analysis results showed that the probiotics supplementation improved hepatocyte injury and significantly reduced the level of ALT (P = 0.00001), AST (P = 0.0009), GGT (P = 0.04), TG (P = 0.01), LDL-C (P = 0.0005), HDL-C (P = 0.0002), insulin (P = 0.003), IR (P = 0.03), BMI (P = 0.03), TNF-α (P = 0.03), and CRP (P = 0.02), respectively, in NAFLD patients.

CONCLUSION

The present study suggests that probiotics therapy may improve liver enzyme levels, regulated lipid metabolism, reduced insulin resistance, and improved inflammation in NAFLD patients. It supports the potential role of probiotics supplementation in the treatment of NAFLD.

Fundamentals and Applications of Artificial Neural Network Modelling of Continuous Bifidobacteria Monoculture at a Low Flow Rate

The application of artificial neural networks (ANNs) to mathematical modelling in microbiology and biotechnology has been a promising and convenient tool for over 30 years because ANNs make it possible to predict complex multiparametric dependencies. This article is devoted to the investigation and justification of ANN choice for modelling the growth of a probiotic strain of Bifidobacterium adolescentis in a continuous monoculture, at low flow rates, under different oligofructose (OF) concentrations, as a preliminary study for a predictive model of the behaviour of intestinal microbiota. We considered the possibility and effectiveness of various classes of ANN. Taking into account the specifics of the experimental data, we proposed two-layer perceptrons as a mathematical modelling tool trained on the basis of the error backpropagation algorithm. We proposed and tested the mechanisms for training, testing and tuning the perceptron on the basis of both the standard ratio between the training and test sample volumes and under the condition of limited training data, due to the high cost, duration and the complexity of the experiments. We developed and tested the specific ANN models (class, structure, training settings, weight coefficients) with new data. The validity of the model was confirmed using RMSE, which was from 4.24 to 980% for different concentrations. The results showed the high efficiency of ANNs in general and bilayer perceptrons in particular in solving modelling tasks in microbiology and biotechnology, making it possible to recommend this tool for further wider applications.

Evidence for long-lasting alterations in the fecal microbiota following prenatal alcohol exposure

BACKGROUND

There is growing evidence that the gut microbiota can be shaped by early-life experiences/exposures, with long-term consequences for brain, behavior, and health. Changes in the gut microbiota have also been identified in neurodevelopmental disorders including Autism Spectrum Disorder and schizophrenia. In contrast, no studies to date have investigated whether the gut microbiota is altered in individuals with Fetal Alcohol Spectrum Disorder (FASD), the neurodevelopmental disorder that results from prenatal alcohol exposure (PAE). The current study was designed to assess the impact of PAE on the fecal microbiota.

METHODS

We used a rodent model in which pregnant Sprague-Dawley rats were provided with an EtOH-containing diet or a control diet throughout gestation. Fecal samples were collected from adult male and female animals and 16s rRNA sequencing was performed.

RESULTS

Overall, PAE rats showed greater richness of bacterial species, with community structure investigations demonstrating distinct clustering by prenatal treatment. In addition, prenatal treatment and sex-specific alterations were observed for many specific microbes. For example, in males, Bacteroides and Bifidobacterium, and in females, Faecalitalea and Proteus, differed in abundance between PAE and control rats.

CONCLUSIONS

Taken together, these results show for the first time that PAE has a long-lasting and sex-specific impact on the fecal microbiota. Further research is needed that considers fetal microbiota in the development of new interventions in FASD.

Why Are Bifidobacteria Important for Infants?

The presence of Bifidobacterium species in the maternal vaginal and fecal microbiota is arguably an evolutionary trait that allows these organisms to be primary colonizers of the newborn intestinal tract. Their ability to utilize human milk oligosaccharides fosters their establishment as core health-promoting organisms throughout life. A reduction in their abundance in infants has been shown to increase the prevalence of obesity, diabetes, metabolic disorder, and all-cause mortality later in life. Probiotic strains have been developed as supplements for premature babies and to counter some of these ailments as well as to confer a range of health benefits. The ability to modulate the immune response and produce short-chain fatty acids, particularly acetate and butyrate, that strengthen the gut barrier and regulate the gut microbiome, makes Bifidobacterium a core component of a healthy infant through adulthood.

Novel Linkages Between Bacterial Composition of Hindgut and Host Metabolic Responses to SARA Induced by High-Paddy Diet in Young Goats

At present, feeding a high-corn diet to goats is used to provide enough protein and energy supply to meet their higher dietary requirements. In fact, because corn grain is commonly scarce in the traditional rice cropping region of southern Asia, paddy is thereby used as an alternative feed applied in goat diets. However, the effects of the high paddy proportion on the microbiota and metabolites of the intestine are unclear. Here, we investigate the effects of high paddy proportion on bacterial community, potential function, and metabolic reaction in the cecum of goats. Sixteen Liuyang black goats were divided into two groups fed either a normal-paddy (NP) diet (55% concentrate) or a high-paddy (HP) diet (90% concentrate) for 5 weeks. Total short-chain fatty acid (SCFA) concentration was higher in the hindgut chyme of the HP-fed goats than in that of the NP-fed goats (p = 0.001). The acetic proportion was significantly decreased and the propionic proportion was increased in the HP group (p &lt; 0.05). The HP diet decreased the value of pH, lactic acid concentration, and lactate dehydrogenase activity but increased the activity of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and amylase, together with lipopolysaccharide concentration in the hindgut chyme of goats (p &lt; 0.05). The abundance rates of the Eubacterium_coprostanoligenes_group was increased (p = 0.050), whereas the abundance of Prevotellaceae_UCG_004, dgA-11_gut_group, Christensenellaceae_R-7_group, Ruminococcaceae_UCG-010, and Desulfovibrio were significantly decreased with the HP diet (p &lt; 0.05). These results suggested that the HP diet altered the microbiota and metabolites, which negatively modified intestinal epithelial health in goats.

Fluoride exposure cause colon microbiota dysbiosis by destroyed microenvironment and disturbed antimicrobial peptides expression in colon

Colon microenvironment and microbiota dysbiosis are closely related to various human metabolic diseases. In this study, a total of 72 healthy female mice were exposed to fluoride (F) (0, 25, 50 and 100 mg/L F^-) in drinking water for 70 days. The effect of F on intestinal barrier and the diversity and composition in colon microbiota have been evaluated. Meanwhile, the relationship among F-induced colon microbiota alterations and antimicrobial peptides (AMPs) expression and short-chain fatty acids (SCFAs) level also been assessed. The results suggested that F decreased the goblet cells number and glycoprotein expression in colon. And further high-throughput 16S rRNA gene sequencing result demonstrated that F exposure induced the diversity and community composition of colonic microbiota significantly changes. Linear Discriminant Analysis Effect Size (LEfSe) analysis identified 11 predominantly characteristic taxa which may be the biomarker in response to F exposure. F-induced intestinal microbiota perturbations lead to the significantly decreased SCFAs levels in colon. Immunofluorescence results showed that F increased the protein expression of interleukin-17A (IL-17A) and IL-22 (P < 0.01) and disturbed the expression of interleukin-17 receptor A (IL-17RA) and IL-22R (P < 0.05 or P < 0.01). In addition, the increased expression of IL-17A and IL-22 cooperatively enhanced the mRNA expression of AMPs which response to F-induced microbiota perturbations. Collectively, destroyed microenvironment and disturbed AMPs are the primary reason of microbiota dysbiosis in colon after F exposure. Colonic homoeostasis imbalance would be helpful for finding the source of F-induced chronic systemic diseases.