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Abstract This study focuses on the resilience of gut microbiota during a five-month multi-interventional nutrition trial. The modulatory effects of beta-glucan, rye bran and two dietary fiber mixtures on the fecal pH and compositional changes of the microbiome of healthy subjects were studied. To analyze the stability of intestinal microbiota, we collected an extensive dataset of sequential fecal samples (23–29 from each participant) during a week of the base, beta-glucan consumption and wash-out periods accompanied by the collection of daily food diary data. Microbiota analyses were also conducted after the end of each fiber intake and wash-out period, along with measurements of fecal organic acids and pH. Based on the dominant bacterial taxa, two prevalent microbiota types were identified. The Prevotella-type microbiota responded more to the tested dietary fibers, while the Bacteroides-type microbiota was the least affected. Three microbiota types could not be clustered and behaved differently. Although we noted individual effects of definite fibers on participants’ gut microbiota and metabolic profile, relative abundances of bacteria remained stable in the base period (z-scores − 2.2 to 2.3). In most cases, the bacterial abundances of the final samples remained within the normal fluctuation range stressing out the resilience of healthy microbiota. The pH of all fecal samples varied between 6.1 and 8.3 and was associated with the concentration of organic acids and microbial composition. The effect of dietary fibers on the metabolism of fecal microbiota clearly depended on the individual microbiota type. Combining the analysis of gut microbiota with knowledge of the properties of dietary fibers would provide a powerful strategy for nutrition guidance and disease prevention.

This study focuses on the resilience of gut microbiota during a five-month multi-interventional nutrition trial. The modulatory effects of beta-glucan, rye bran and two dietary fiber mixtures on the fecal pH and compositional changes of the microbiome of healthy subjects were studied. To analyze the stability of intestinal microbiota, we collected an extensive dataset of sequential fecal samples (23–29 from each participant) during a week of the base, beta-glucan consumption and wash-out periods accompanied by the collection of daily food diary data. Microbiota analyses were also conducted after the end of each fiber intake and wash-out period, along with measurements of fecal organic acids and pH. Based on the dominant bacterial taxa, two prevalent microbiota types were identified. The Prevotella-type microbiota responded more to the tested dietary fibers, while the Bacteroides-type microbiota was the least affected. Three microbiota types could not be clustered and behaved differently. Although we noted individual effects of definite fibers on participants’ gut microbiota and metabolic profile, relative abundances of bacteria remained stable in the base period (z-scores − 2.2 to 2.3). In most cases, the bacterial abundances of the final samples remained within the normal fluctuation range stressing out the resilience of healthy microbiota. The pH of all fecal samples varied between 6.1 and 8.3 and was associated with the concentration of organic acids and microbial composition. The effect of dietary fibers on the metabolism of fecal microbiota clearly depended on the individual microbiota type. Combining the analysis of gut microbiota with knowledge of the properties of dietary fibers would provide a powerful strategy for nutrition guidance and disease prevention. [ABSTRACT FROM AUTHOR]

Background: Despite therapy advances, one of the leading causes of cancer deaths still remains lung cancer. To improve current treatments or prevent nonsmall cell lung cancer (NSCLC), the role of the nutrition in cancer onset and progression needs to be understood in more detail. While in colorectal cancer, the influence of local microbiota derived SCFAs have been well investigated, the influence of SCFA on lung cancer cells via peripheral blood immune system should be investigated more deeply. In this respect, nutrients absorbed via the gut might affect the tumor microenvironment (TME) and thus play an important role in tumor cell growth. Objective: This study focuses on the impact of the short-chain fatty acid (SCFA) Sodium Butyrate (SB), on lung cancer cell survival. We previously described a protumoral role of glucose on A549 lung adenocarcinoma cell line. In this study, we wanted to know if SB would counteract the effect of glucose and thus cultured A549 and H520 in vitro with and without SB in the presence or absence of glucose and investigated how the treatment with SB affects the survival of lung cancer cells and its influence on immune cells fighting against lung cancer. Methods: In this study, we performed cell culture experiments with A549, H520 and NSCLC-patient-derived epithelial cells under different SB levels. To investigate the influence on the immune system, we performed in vitro culture of peripheral mononuclear blood cells (PBMC) from control, smoker and lung cancer patients with increasing SB concentrations. Results: To investigate the effect of SB on lung tumor cells, we first analyzed the effect of 6 different concentrations of SB on A549 cells at 48 and 72 hours cell culture. Here we found that, SB treatment reduced lung cancer cell survival in a concentration dependent manner. We next focused our deeper analysis on the two concentrations, which caused the maximal reduction in cell survival. Here, we observed that SB led to cell cycle arrest and induced early apoptosis in A549 lung cancer cells. The expression of cell cycle regulatory proteins and A549 lung cancer stem cell markers (CD90) was induced. Additionally, this study explored the role of interferon-gamma (IFN-g) and its receptor (IFN-g-R1) in combination with SB treatment, revealing that, although IFN-g-R1 expression was increased, IFN-g did not affect the efficacy of SB in reducing tumor cell viability. Furthermore, we examined the effects of SB on immune cells, specifically CD8 + T cells and natural killer (NK) cells from healthy individuals, smokers, and NSCLC patients. SB treatment resulted in a decreased production of IFN-g and granzyme B in CD8+ T cells and NK cells. Moreover, SB induced IFN-g-R1 in NK cells and CD4+ T cells in the absence of glucose both in PBMCs from controls and NSCLC subjects. Conclusion: Overall, this study highlights the potential of SB in inhibiting lung cancer cell growth, triggering apoptosis, inducing cell cycle arrest, and modulating immune responses by activating peripheral blood CD4+ T cells while selectively inducing IFN-g-R1 in NK cells in peripheral blood and inhibiting peripheral blood CD8+ T cells and NK cells. Thus, understanding the mechanisms of action of SB in the TME and its influence on the immune system provide valuable insights of potentially considering SB as a candidate for adjunctive therapies in NSCLC. [ABSTRACT FROM AUTHOR]

ABSTRACT: This study aimed to evaluate the effect of low molecular weight Acanthopanax polysaccharides on simulated digestion, probiotics, and intestinal flora of broilers in vitro. The experiments were carried out by H2O2-Vc degradation of Acanthopanax polysaccharides, in vitro simulated digestion to evaluate the digestive performance of polysaccharides with different molecular weights, in vitro probiotic evaluation of the probiotic effect of polysaccharides on lactobacilli and bifidobacteria, in vitro anaerobic fermentation and high-throughput sequencing of 16S rRNA genes to study the impact of Acanthopanax polysaccharides on the intestinal flora of broilers, and the effect of Acanthopanax polysaccharides on the short-chain fatty acids of intestines were determined by GC-MS method. The results showed that the molecular weight of Acanthopanax polysaccharide (ASPS) was 9,543 Da, and the molecular weights of polysaccharides ASPS-1 and ASPS-2 were reduced to 4,288 Da and 3,822 Da after degradation, and the particle sizes, PDIs, and viscosities were also significantly decreased. ASPS-1 has anti-digestive properties and better in vitro probiotic properties. The addition of ASPS-1 regulates the structure of intestinal microorganisms by regulating fecalibacterium to produce short-chain fatty acids, promoting the colonization of beneficial bacteria such as fecalibacterium, paraprevotella and diminishing the prevalence of detrimental bacteria such as Fusobacteria. Interestingly the ASPS-1 group found higher levels of Paraprevotella, which degraded trypsin in the gut, reducing inflammation, acted as a gut protector, and was influential in increasing the levels of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and total SCFAs in the fermented feces. Therefore, the degraded ASPS-1 can better regulate the structure of intestinal flora and promote the production of SCFAs, creating possibilities for its use as a potential prebiotic, which is conducive to the intestinal health of poultry.

Abstract Background The promising yet barely investigated anaerobic species Phocaeicola vulgatus (formerly Bacteroides vulgatus) plays a vital role for human gut health and effectively produces organic acids. Among them is succinate, a building block for high-value-added chemicals. Cultivating anaerobic bacteria is challenging, and a detailed understanding of P. vulgatus growth and metabolism is required to improve succinate production. One significant aspect is the influence of different gas concentrations. CO2 is required for the growth of P. vulgatus. However, it is a greenhouse gas that should not be wasted. Another highly interesting aspect is the sensitivity of P. vulgatus towards O2. In this work, the effects of varying concentrations of both gases were studied in the in-house developed Respiratory Activity MOnitoring System (RAMOS), which provides online monitoring of CO2, O2, and pressure under gassed conditions. The RAMOS was combined with a gas mixing system to test CO2 and O2 concentrations in a range of 0.25-15.0 vol% and 0.0-2.5 vol%, respectively. Results Changing the CO2 concentration in the gas supply revealed a CO2 optimum of 3.0 vol% for total organic acid production and 15.0 vol% for succinate production. It was demonstrated that the organic acid composition changed depending on the CO2 concentration. Furthermore, unrestricted growth of P. vulgatus up to an O2 concentration of 0.7 vol% in the gas supply was proven. The viability decreased rapidly at concentrations larger than or equal to 1.3 vol% O2. Conclusions The study showed that P. vulgatus requires little CO2, has a distinct O2 tolerance and is therefore well suited for industrial applications.

Among all non-communicable diseases, Cardiovascular Diseases (CVDs) stand as the leading global cause of mortality. Within this spectrum, Myocardial Infarction (MI) strikingly accounts for over 15 % of all deaths. The intricate web of risk factors for MI, comprising family history, tobacco use, oral health, hypertension, nutritional pattern, and microbial infections, is firmly influenced by the human gut and oral microbiota, their diversity, richness, and dysbiosis, along with their respective metabolites. Host genetic factors, especially allelic variations in signaling and inflammatory markers, greatly affect the progression or severity of the disease. Despite the established significance of the human microbiome-nutrient-metabolite interplay in associations with CVDs, the unexplored terrain of the gut-heart-oral axis has risen as a critical knowledge gap. Moreover, the pivotal role of the microbiome and the complex interplay with host genetics, compounded by age-related changes, emerges as an area of vital importance in the development of MI. In addition, a distinctive disease susceptibility and severity influenced by gender-based or ancestral differences, adds a crucial insights to the association with increased mortality. Here, we aimed to provide an overview on interactions of microbiome (oral and gut) with major risk factors (tobacco use, alcohol consumption, diet, hypertension host genetics, gender, and aging) in the development of MI and therapeutic regulation.

Metabolism of dietary fibres by colon microbiota plays an important role for human health. Personal data from a nutrition study (57 subjects) were analysed to elucidate quantitative associations between the diet, faecal microbiome, organic acid concentrations and pH. Ratios of the predominant acids acetate, butyrate and propionate ranged from 1:0.67:0.27 to 1:0.17:0.36. Pectin-rich diets resulted in higher faecal acetate concentrations. Negative correlation between faecal pH and BSS was observed. Higher faecal pH and lower acid concentrations were related to the higher abundance of amino acid degrading Clostridium, Odoribacter and Eubacterium coprostanoligenes, which are weak carbohydrate fermenting taxa. Propionic acid correlated especially to high abundance of Prevotella and low abundance of proteobacteria. The acetate to propionate ratio of the Prevotella enterotype was about half of that of the Bacteroides enterotype. Based on the results we suggest the measurement of faecal pH and organic acid composition for research and diagnostic purposes.

BackgroundDespite therapy advances, one of the leading causes of cancer deaths still remains lung cancer. To improve current treatments or prevent non-small cell lung cancer (NSCLC), the role of the nutrition in cancer onset and progression needs to be understood in more detail. While in colorectal cancer, the influence of local microbiota derived SCFAs have been well investigated, the influence of SCFA on lung cancer cells via peripheral blood immune system should be investigated more deeply. In this respect, nutrients absorbed via the gut might affect the tumor microenvironment (TME) and thus play an important role in tumor cell growth.ObjectiveThis study focuses on the impact of the short-chain fatty acid (SCFA) Sodium Butyrate (SB), on lung cancer cell survival. We previously described a pro-tumoral role of glucose on A549 lung adenocarcinoma cell line. In this study, we wanted to know if SB would counteract the effect of glucose and thus cultured A549 and H520 in vitro with and without SB in the presence or absence of glucose and investigated how the treatment with SB affects the survival of lung cancer cells and its influence on immune cells fighting against lung cancer.MethodsIn this study, we performed cell culture experiments with A549, H520 and NSCLC-patient-derived epithelial cells under different SB levels. To investigate the influence on the immune system, we performed in vitro culture of peripheral mononuclear blood cells (PBMC) from control, smoker and lung cancer patients with increasing SB concentrations.ResultsTo investigate the effect of SB on lung tumor cells, we first analyzed the effect of 6 different concentrations of SB on A549 cells at 48 and 72 hours cell culture. Here we found that, SB treatment reduced lung cancer cell survival in a concentration dependent manner. We next focused our deeper analysis on the two concentrations, which caused the maximal reduction in cell survival. Here, we observed that SB led to cell cycle arrest and induced early apoptosis in A549 lung cancer cells. The expression of cell cycle regulatory proteins and A549 lung cancer stem cell markers (CD90) was induced. Additionally, this study explored the role of interferon-gamma (IFN-γ) and its receptor (IFN-γ-R1) in combination with SB treatment, revealing that, although IFN-γ-R1 expression was increased, IFN-γ did not affect the efficacy of SB in reducing tumor cell viability. Furthermore, we examined the effects of SB on immune cells, specifically CD8+ T cells and natural killer (NK) cells from healthy individuals, smokers, and NSCLC patients. SB treatment resulted in a decreased production of IFN-γ and granzyme B in CD8+ T cells and NK cells. Moreover, SB induced IFN-γ-R1 in NK cells and CD4+ T cells in the absence of glucose both in PBMCs from controls and NSCLC subjects.ConclusionOverall, this study highlights the potential of SB in inhibiting lung cancer cell growth, triggering apoptosis, inducing cell cycle arrest, and modulating immune responses by activating peripheral blood CD4+ T cells while selectively inducing IFN-γ-R1 in NK cells in peripheral blood and inhibiting peripheral blood CD8+ T cells and NK cells. Thus, understanding the mechanisms of action of SB in the TME and its influence on the immune system provide valuable insights of potentially considering SB as a candidate for adjunctive therapies in NSCLC.

The GG genotype of the Patatin-like phosphatase domain-containing 3 (PNPLA3), dietary fat, short-chain fatty acids (SCFA) and branched-chain amino acids (BCAA) are linked with non-alcoholic fatty liver disease. We studied the impact of the quality of dietary fat on plasma (p) and fecal (f) SCFA and p-BCAA in men homozygous for the PNPLA3 rs738409 variant (I148M). Eighty-eight randomly assigned men (age 67.8 ± 4.3 years, body mass index 27.1 ± 2.5 kg/m2) participated in a 12-week diet intervention. The recommended diet (RD) group followed the National and Nordic nutrition recommendations for fat intake. The average diet (AD) group followed the average fat intake in Finland. The intervention resulted in a decrease in total p-SCFAs and iso-butyric acid in the RD group (p = 0.041 and p = 0.002). Valeric acid (p-VA) increased in participants with the GG genotype regardless of the diet (RD, 3.6 ± 0.6 to 7.0 ± 0.6 µmol/g, p = 0.005 and AD, 3.8 ± 0.3 to 9.7 ± 8.5 µmol/g, p = 0.015). Also, genotype relation to p-VA was seen statistically significantly in the RD group (CC: 3.7 ± 0.4 to 4.2 ± 1.7 µmol/g and GG: 3.6 ± 0.6 to 7.0 ± 0.6 µmol/g, p = 0.0026 for time and p = 0.004 for time and genotype). P-VA, unlike any other SCFA, correlated positively with plasma gamma-glutamyl transferase (r = 0.240, p = 0.025). Total p-BCAAs concentration changed in the AD group comparing PNPLA3 CC and GG genotypes (CC: 612 ± 184 to 532 ± 149 µmol/g and GG: 587 ± 182 to 590 ± 130 µmol/g, p = 0.015 for time). Valine decreased in the RD group (p = 0.009), and leucine decreased in the AD group (p = 0.043). RD decreased total fecal SCFA, acetic acid (f-AA), and butyric acid (f-BA) in those with CC genotype (p = 0.006, 0.013 and 0.005, respectively). Our results suggest that the PNPLA3 genotype modifies the effect of dietary fat modification for p-VA, total f-SCFA, f-AA and f-BA, and total p-BCAA. [ABSTRACT FROM AUTHOR]

Background: The promising yet barely investigated anaerobic species Phocaeicola vulgatus (formerly Bacteroides vulgatus) plays a vital role for human gut health and effectively produces organic acids. Among them is succinate, a building block for high-value-added chemicals. Cultivating anaerobic bacteria is challenging, and a detailed understanding of P. vulgatus growth and metabolism is required to improve succinate production. One significant aspect is the influence of different gas concentrations. CO2 is required for the growth of P. vulgatus. However, it is a greenhouse gas that should not be wasted. Another highly interesting aspect is the sensitivity of P. vulgatus towards O2. In this work, the effects of varying concentrations of both gases were studied in the in-house developed Respiratory Activity MOnitoring System (RAMOS), which provides online monitoring of CO2, O2, and pressure under gassed conditions. The RAMOS was combined with a gas mixing system to test CO2 and O2 concentrations in a range of 0.25-15.0 vol% and 0.0-2.5 vol%, respectively. Results: Changing the CO2 concentration in the gas supply revealed a CO2 optimum of 3.0 vol% for total organic acid production and 15.0 vol% for succinate production. It was demonstrated that the organic acid composition changed depending on the CO2 concentration. Furthermore, unrestricted growth of P. vulgatus up to an O2 concentration of 0.7 vol% in the gas supply was proven. The viability decreased rapidly at concentrations larger than or equal to 1.3 vol% O2. Conclusions: The study showed that P. vulgatus requires little CO2, has a distinct O2 tolerance and is therefore well suited for industrial applications. [ABSTRACT FROM AUTHOR]

• The prevalence of allergic diseases in the world reported so far is approximately 20%. • Long-term relief from allergic diseases is one of the major concerns worldwide and avoidance is to only management strategy. • Mesenchymal stem cells (MSCs) might be promising potential alternative treatment approach for allergy sufferers. • Recent evidence suggests that MSCs as immunomodulators for alleviating allergic airway inflammation and food allergy symptoms in mice. • Effect of short chain fatty acids (SCFAs) produced by gut microbes in regulation of the regeneration and differentiation of MSCs needs further investigation in the allergy treatment. Allergic diseases are broadly classified as IgE-mediated type-I hypersensitivity immune reactions due to exposure to typically harmless substances known as allergens. These allergenic substances activate antigen presenting cells, which further triggers T-helper 2 cells immune response and class switch B-cells for synthesis of allergen-specific IgE, followed by classical activation of inflammatory mast cells and eosinophils, which releases preformed mediators involved in the cascade of allergic symptoms. However, the role of Mesenchymal stem cells (MSCs) in tissue repair ability and immunomodulation, makes them as an appropriate tool for treatment of various allergic diseases. Several clinical and preclinical studies show that MSCs could be a promising alternative therapy to allergic diseases. Further, short chain fatty acids, produced from gut microbes by breaking down complex fibre-rich foods, acts through G-coupled receptor mediated activation of MSCs, and their role as key players involved in amelioration of allergic inflammation needs further investigation. Therefore, there is a need for understating the role of SCFAs on the activation of MSCs, which might shed light on the development of new therapeutic regime in allergy treatment. In summary, this review focuses on the underlying of therapeutic role of MSCs in different allergic diseases and the prospects of SCFA and MSC therapy. [ABSTRACT FROM AUTHOR]

Increased colonic butyrate from microbial fermentation of fibre may protect from colorectal cancer (CRC). Dietary butyrylated high amylose maize starch (HAMSB) delivers butyrate to the large bowel. The objective of this clinical trial (AusFAP) is to evaluate potential chemoprotective effects of HAMSB on polyposis in individuals with a genetic form of colon cancer, Familial Adenomatous Polyposis (FAP).The study is a multi-site, double blind, randomised, placebo-controlled crossover trial undertaken at major hospitals in Australia. After a baseline endoscopy participants consume either 40g/day of HAMSB or placebo (low amylose maize) starch for 26 weeks. After another endoscopic examination participants consume the alternate starch for 26 weeks. A third endoscopy at 52 weeks is followed by 26 weeks' washout and a final endoscopy at 78 weeks. Primary outcome measure is the global large bowel polyp number. Secondary measures include global polyp size counts, and number and size of polyps at two tattoo sites: one cleared of polyps at baseline, and another safely chosen with polyps left in situ during the study. Other secondary outcome measures include the effects of intervention on cellular proliferation in colonic biopsies, faecal measures including short chain fatty acid concentrations, and participants’ dietary intakes. Generalized linear mixed models analysis will be used to estimate differences in primary outcomes between intervention and placebo periods.This study represents the first clinical evaluation of the effects of increased colonic butyrate on polyp burden in FAP which, if effective, may translate to lower risk of sporadic CRC in the community.Australian New Zealand Clinical Trials Registry Number: 12612000804886.

Phocaeicola vulgatus (formerly Bacteroides vulgatus), an anaerobic gut bacterium, produces several organic acids. Research on P. vulgatus is still in its infancy. However, a detailed understanding of P. vulgatus growth and metabolism is essential for its assessment as an organic acid producer. Media variations, including different initial glucose and NH 4 Cl concentrations and osmolalities, are significant means to yield higher organic acid titers. Furthermore, examining different nitrogen and carbon sources is important to evaluate the potential of P. vulgatus for growth on renewable resources. Cultivations were performed in an in-house built device for anaerobic online-monitoring of fluorescence and scattered light in microtiter plates. Results revealed that the highest organic acid concentrations were reached while using galactose, glucose, or xylose as a carbon source, high osmolalities, and 0.25 g L -1 NH 4 Cl. In addition, the organic acid composition changed with changing carbon and nitrogen sources. P. vulgatus was successfully further characterized, thereby contributing to a faster characterization of other anaerobic strains and paving the way for anaerobic organic acid production., (© 2024 The Author(s). Biotechnology Progress published by Wiley Periodicals LLC on behalf of American Institute of Chemical Engineers.)

Influenza vaccination is an effective public health measure to reduce the risk of influenza illness, particularly when the vaccine is well matched to circulating strains. Notwithstanding, the efficacy of influenza vaccination varies greatly among vaccinees due to largely unknown immunological determinants, thereby dampening population-wide protection. Here, we report that dietary fibre may play a significant role in humoral vaccine responses. We found dietary fibre intake and the abundance of fibre-fermenting intestinal bacteria to be positively correlated with humoral influenza vaccine-specific immune responses in human vaccinees, albeit without reaching statistical significance. Importantly, this correlation was largely driven by first-time vaccinees; prior influenza vaccination negatively correlated with vaccine immunogenicity. In support of these observations, dietary fibre consumption significantly enhanced humoral influenza vaccine responses in mice, where the effect was mechanistically linked to short-chain fatty acids, the bacterial fermentation product of dietary fibre. Overall, these findings may bear significant importance for emerging infectious agents, such as COVID-19, and associated de novo vaccinations.

Influenza vaccination is an effective public health measure to reduce the risk of influenza illness, particularly when the vaccine is well matched to circulating strains. Notwithstanding, the efficacy of influenza vaccination varies greatly among vaccinees due to largely unknown immunological determinants, thereby dampening population-wide protection. Here, we report that dietary fibre may play a significant role in humoral vaccine responses. We found dietary fibre intake and the abundance of fibre-fermenting intestinal bacteria to be positively correlated with humoral influenza vaccine-specific immune responses in human vaccinees, albeit without reaching statistical significance. Importantly, this correlation was largely driven by first-time vaccinees; prior influenza vaccination negatively correlated with vaccine immunogenicity. In support of these observations, dietary fibre consumption significantly enhanced humoral influenza vaccine responses in mice, where the effect was mechanistically linked to short-chain fatty acids, the bacterial fermentation product of dietary fibre. Overall, these findings may bear significant importance for emerging infectious agents, such as COVID-19, and associated de novo vaccinations. [ABSTRACT FROM AUTHOR]

• Complex aetiology and systemic impact on various organs made RA challenging. • Dysbiosis emphasized the significance of microbial homeostasis. • The mutual relationship between RA and Gut microbiota was investigated. • Probiotics emerged as a hopeful avenue for RA management. Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation and joint damage. Existing treatment options primarily focus on managing symptoms and slowing disease progression, often with side effects and limitations. The gut microbiome, a vast community of microorganisms present in the gastrointestinal tract, plays a crucial role in health and disease. Recent research suggests a bidirectional relationship between the gut microbiome and RA, highlighting its potential as a therapeutic option. This review focuses on the interaction between the gut microbiome and RA development, by discussing how dysbiosis, an imbalance in gut bacteria, can contribute to RA through multiple mechanisms such as molecular mimicry, leaky gut, and metabolic dysregulation. Probiotics, live microorganisms with health benefits, are emerging as promising tools for managing RA. They can prevent the negative effects of dysbiosis by displacing harmful bacteria, producing anti-inflammatory metabolites like short-chain fatty acids (SCFA), Directly influencing immune cells, and modifying host metabolism. animal and clinical studies demonstrate the potential of probiotics in improving RA symptoms and disease outcomes. However, further research is needed to optimize probiotic strains, dosages, and treatment protocols for personalized and effective management of RA. This review summarizes the current understanding of the gut microbiome and its role in RA and discusses future research directions. In addition to the established role of gut dysbiosis in RA, emerging strategies like fecal microbiota transplantation, prebiotics, and postbiotics offer exciting possibilities. However, individual variations in gut composition necessitate personalized treatment plans. Long-term effects and clear regulations need to be established. Future research focusing on metagenomic analysis, combination therapies, and mechanistic understanding will unlock the full potential of gut microbiome modulation for effective RA management. [ABSTRACT FROM AUTHOR]

Abstract The main components of the non-starch polysaccharide (NSP) fraction of wheat flour are arabinoxylan (AX) and β-glucan. These are also present in other cereal grains, but their proportions vary with AX being the major component in wheat and rye and β-glucan in barley and oats. Therefore, it was hypothesised that these NSPs could act synergistically when fermented in vitro at the ratios present in the major foods consumed, resulting in increased prebiotic activity. AX and β-glucan were therefore tested in in vitro fermentation studies to assess their prebiotic activity when used individually and/or in different ratios. Short-chain fatty-acids (SCFAs) produced from in vitro fermentation were measured using HPLC and bacterial populations were measured using flow cytometry with fluorescence in situ hybridisation (Flow-FISH). Fermentation of AX alone resulted in a significant bifidogenic activity and increased concentrations of SCFAs, mainly acetate, after 8–24 h of fermentation, however β-glucan alone did not show prebiotic activity. The greatest prebiotic activity, based on concentration of total SCFAs and increases in total bacteria as well as beneficial Bifidobacterium and Clostridium coccoides/Eubacterium groups, was observed when AX and β-glucan were combined at a 3:1 ratio, which corresponds to their ratios in wheat flour which is major source of cereal fibre in the diet. This indicates that the population of bacteria in the human GI tract may be modulated by the composition of the fibre in the diet, to maximise the prebiotic potential.

Rationale: Functional activity of upper respiratory tract and oral microbiota has a high informational potential for diagnostics of infectious disease and for development of preventive measure, which is to be explained by rapid variability and high activity of bacteria in this location.Aim: To determine statistical characteristics of concentrations and ratios of the oropharyngeal short chain fatty acids (SCFA) (i.e., functional activity of oropharyngeal microbiota) depending on age of patients without infectious disorder of upper respiratory tract and oral cavity.Materials and methods: Gas liquid chromatography was used to measure SCFA concentrations in saliva from 683 patients aged from 1 month to 85 years who did not have any infections of respiratory tract and oral cavity. Age intervals with homogenous salivary SCFA levels were determined with constant trends in their means (medians) with one-month accuracy. The resulting parameters for the identified age intervals were compared with Mann-Whitney test at 95% significance level (p < 0.05).Results: There were no significant differences between median total SCFA levels (8.04 [4.85; 14.22] mmol/G) and median acetic acid levels (6.27 [3.79; 11.21] mmol/G) in saliva from patients of all ages from 1 month to 85 years. For all other parameters, from 2 to 3 steps of changes were found that occurred at the age of 4 months and 14 years. After the age of 14, the concentrations of propionic and butyric acid significantly increased, whereas those of valeric and caproic acids, as well as of the branched chain SCFA decreased. Correspondingly, after the age of 14, the mean structural index increased from 0.25 to 0.27 U (p < 0.05). The isoacid index decreased with age in two steps: at the age of 4 months from 1.89 to 1.04 U (p < 0.05) and later at the age of 14 years to 0.74 U (p < 0.05).Conclusion: Salivary SCFA levels become stable at the age of 14. The structural index and the isoacid index are most sensitive to the integral changes in the microbiota composition. Analysis of the results of studies on metabolic functioning of microflora should be based on mathematic modeling and multifactorial statistics in three age intervals: from birth to 4 months of age, from 4 months to 14 years and over 14 years.

Rationale: Multiple biological effects of short chain fatty acids (SCFA) and the possibility to modify their composition by probiotics and prebiotics is in the focus of attention of researchers and clinicians. However, big studies with assessment of the whole spectrum of SCFA produced by gut microbiome and calculated indexes of their relative content are lacking.Aim: To determine concentrations and ratios of fecal SCFA (functional activity of the gut microbiome) depending on the age of patients without gastrointestinal disorders.Materials and methods: SCFA fecal concentrations were measured by gas liquid chromatography in 6836 patients aged from 1 month to 85 years without any functional or chronic gastrointestinal pathology, infectious diseases and/or obesity. The time periods with homogenous values of the parameters were determined by identification of constant trends of their means (medians) with 1-month accuracy in children below 5 years of age and with 1-year accuracy in the patients above 1 years of age. The results obtained for the chosen time intervals were compared with Mann-Whitney's test at 95% significance level (p < 0.05).Results: We performed descriptive statistics for absolute and relative content of SCFA and their structural indexes. It was shown that the parameters characterizing functional activity of gut microbiome have different critical stages in their age-related changes. For each parameter, 2 or 3 stages of changes were identified that occurred at early age, mainly before the age of two. The final SCFA structure was stable by 2 years and 5 months of age. Total SCFA levels reached those typical for adults by the age of 12. The structural index was most sensitive to integrated changes of the microbiome structure.Conclusion: Age-related characteristics of gut microbiome should be taken into account when performing clinical studies on effectiveness of therapeutic interventions and assessing the parameters in a given patient.

Dietary products with prebiotic properties have been used to promote protective effects during inflammatory process. Prebiotics are source of short chain fatty acids (SCFAs) that have been associated with anti-inflammatory effects. Banana (Musa sp. AAA) is rich in resistant starch, which is used by colonic microbiota to SCFAs production. For this, we used the trinitrobenzenesulphonic acid model of intestinal inflammation to evaluate whether intestinal anti-inflammatory effect is related to prebiotic effects. Dietary intervention with green dwarf banana flour (5% or 10%) increased acetate, propionate and butyrate concentration. The protective effects was also evidenced by reduction in extension of lesion, inhibition of myeloperoxidase activity, prevention in glutathione depletion, increased mucin production and mucosal healing. This way, dietary green dwarf banana modulates oxidative stress and colonic production of SCFAs increasing intestinal tissue protection and may be used as a complementary product to prevent or avoid relapse of symptoms in inflammatory bowel diseases.

Purpose: To test the prebiotic activity of wheat arabinogalactan-peptide (AGP), which is a soluble dietary fibre composed of arabinogalactan polysaccharide linked to a 15-residue peptide, which accounts for up to 0.4% of the dry weight of wheat flour. Methods: The prebiotic activity of AGP prepared from white wheat flour was tested using in vitro fermentation by colonic bacteria in automated pH-controlled anaerobic stirred batch cultures and compared to fructooligosaccharide (FOS) and wheat flour arabinoxylan (AX). Bacterial populations were measured using fluorescence in situ hybridisation (flow-FISH) and short chain fatty acid (SCFA) concentrations were measured using HPLC. Results: Fermentation of AGP resulted in a significant bifidogenic activity and increased concentrations of SCFAs, mainly acetate after 24 h of fermentation. Conclusions: These results were comparable to those obtained with AX and confirm the prebiotic potential of AGP. Furthermore, fermentation of a mixture of AGP and AX was faster compared to the single substrates and more similar to FOS, indicating that combinations of fermentable carbohydrates with different structures are potentially more effective as prebiotics than single substrates. [ABSTRACT FROM AUTHOR]

The main components of the non-starch polysaccharide (NSP) fraction of wheat flour are arabinoxylan (AX) and β-glucan. These are also present in other cereal grains, but their proportions vary with AX being the major component in wheat and rye and β-glucan in barley and oats. Therefore, it was hypothesised that these NSPs could act synergistically when fermented in vitro at the ratios present in the major foods consumed, resulting in increased prebiotic activity. AX and β-glucan were therefore tested in in vitro fermentation studies to assess their prebiotic activity when used individually and/or in different ratios. Short-chain fatty-acids (SCFAs) produced from in vitro fermentation were measured using HPLC and bacterial populations were measured using flow cytometry with fluorescence in situ hybridisation (Flow-FISH). Fermentation of AX alone resulted in a significant bifidogenic activity and increased concentrations of SCFAs, mainly acetate, after 8–24 h of fermentation, however β-glucan alone did not show prebiotic activity. The greatest prebiotic activity, based on concentration of total SCFAs and increases in total bacteria as well as beneficial Bifidobacterium and Clostridium coccoides/Eubacterium groups, was observed when AX and β-glucan were combined at a 3:1 ratio, which corresponds to their ratios in wheat flour which is major source of cereal fibre in the diet. This indicates that the population of bacteria in the human GI tract may be modulated by the composition of the fibre in the diet, to maximise the prebiotic potential. [ABSTRACT FROM AUTHOR]

As the primordial, prokaryotic inhabitants on Earth, microbial entities were responsible for significant influences on the pathways taken in the development of life as we know it. The manifestation of numerous pathologies in humans is considered to be intrinsically associated with microbial dysbiosis in the gut (i.e. a poorly balanced microbiota). Such adverse health conditions include obesity, chronic fatigue syndrome, cancer, cardiovascular issues, neurological disorders, colitis, irritable bowel syndrome (IBS), and rheumatoid arthritis. Endosymbiotic events at the single cell level took place billions of years ago, eventually leading to eukaryotes, photosynthesis, and multicellularity. Macroalgae (seaweeds) were amongst the first organisms to develop these characteristics. Microbes and macroalgae interacted in a pattern of co-evolution, a process that applies to most, if not all living organisms. It is recognized that the normal human microbiome consists of over a trillion microorganisms, including about 2 000 commensal bacterial species typically stationed in the gut. Many of these live in the colon, where they function in the digestion of foods, releasing bio-available nutrients, bioactive molecules, and various metabolites. They mediate communication signals between the gut and the brain, and promote the normal development of immune function, metabolic activities, behaviour, and neurological stability. As very early humans foraged for food, some would have benefitted from coastal diets, rich in seaweeds and associated microbes. Such diets would have consistently provided all the nutrients essential for survival and growth, and as such, could have conveyed competitive advantages and contributed to enhanced cognitive sophistication. This mini-review article highlights studies regarding the health benefits of dietary fibres and the production of short chain fatty acids (SCFA). Insights are offered regarding the positive effects the inclusion of macroalgae into the standard, Western diet can deliver in terms of providing appropriate fodder for those microbial populations deemed beneficial to human health and wellness. [ABSTRACT FROM AUTHOR]

Pulmonary and extrapulmonary acute respiratory distress syndrome (ARDS) is a life-threatening respiratory failure associated with high mortality. Despite progress in our understanding of the pathological mechanism causing the crippling illness, there are currently no targeted pharmaceutical treatments available for it. Recent discoveries have emphasized the existence of a potential nexus between gut and lung health fueling novel approaches including probiotics for the treatment of ARDS. We thus investigated the prophylactic-potential of Lactobacillus rhamnosus -(LR) in lipopolysaccharide (LPS)-induced pulmonary and cecal ligation puncture (CLP) induced extrapulmonary ARDS mice. Our in-vivo findings revealed that pretreatment with LR significantly ameliorated vascular-permeability (edema) of the lungs via modulating the neutrophils along with significantly reducing the expression of inflammatory-cytokines in the BALF, lungs and serum in both pulmonary and extrapulmonary mice-models. Interestingly, our ex-vivo immunofluorescence and flow cytometric data suggested that mechanistically LR via short chain fatty acids (butyrate being the most potent and efficient in ameliorating the pathophysiology of both pulmonary and extra-pulmonary ARDS) targets the phagocytic and neutrophils extracellular traps (NETs) releasing potential of neutrophils. Moreover, our in-vivo data further corroborated our ex-vivo findings and suggested that butyrate exhibits enhanced potential in ameliorating the pathophysiology of ARDS via reducing the infiltration of neutrophils into the lungs. Altogether, our study establishes the prophylactic role of LR and its associated metabolites in the prevention and management of both pulmonary and extrapulmonary ARDS via targeting neutrophils. [ABSTRACT FROM AUTHOR]

Short chain fatty acids (SCFA), principally acetate, propionate, and butyrate, are produced by fermentation of dietary fibers by the gut microbiota. SCFA regulate the growth and virulence of enteric pathogens, such as enterohemorrhagic E. coli (EHEC), Klebsiella and Salmonella. We sought to investigate the impact of SCFA on growth and virulence of pathosymbiont E. coli associated with inflammatory bowel disease (IBD) and colorectal cancer (CRC), and their role in regulating host responses to bacterial infection in vitro. We found that under ileal conditions (pH = 7.4; 12 mM total SCFA), SCFA significantly (p < 0.05) potentiate the growth and motility of pathosymbiont E. coli. However, under colonic conditions (pH = 6.5; 65 to 123 mM total SCFA), SCFA significantly (p < 0.05) inhibit growth in a pH dependent fashion (up to 60%), and down-regulate virulence gene expression (e.g., fliC, fimH, htrA, chuA, pks). Functional analysis reveals that colonic SCFA significantly (p < 0.05) inhibit E. coli motility (up to 95%), infectivity (up to 60%), and type 1 fimbria-mediated agglutination (up to 50%). In addition, SCFA significantly (p < 0.05) inhibit the activation of NF-κB, and IL-8 production by epithelial cells. Our findings provide novel insights on the role of the regional chemical microenvironment in regulating the growth and virulence of pathosymbiont E. coli and opportunities for therapeutic intervention.

Globally, marine species’ distributions are being modified due to rising ocean temperatures. Increasing evidence suggests a circum-global pattern of poleward extensions in the distributions of many tropical herbivorous species, including the ecologically important rabbitfish Siganus fuscescens. Adaptability of a species to such new environments may be heavily influenced by the composition of their gastrointestinal microbe fauna, which is fundamentally important to animal health. Siganus fuscescens thus provides an opportunity to assess the stability of gastrointestinal microbes under varying environmental conditions. The gastrointestinal microbial communities of S. fuscescens were characterized over 2,000 km of Australia’s western coast, from tropical to temperate waters, including near its current southern distributional limit. Sequencing of the 16S rRNA gene demonstrated that each population had a distinct hindgut microbial community, and yet, 20 OTUs occurred consistently in all samples. These OTUs were considered the ‘core microbiome’ and were highly abundant, composing between 31 and 54% of each population. Furthermore, levels of short chain fatty acids, an indicator of microbial fermentation activity, were similar among tropical and temperate locations. These data suggest that flexibility in the hindgut microbiome may play a role in enabling such herbivores to colonize new environments beyond their existing range.

Globally, marine species’ distributions are being modified due to rising ocean temperatures. Increasing evidence suggests a circum-global pattern of poleward extensions in the distributions of many tropical herbivorous species, including the ecologically important rabbitfish Siganus fuscescens. Adaptability of a species to such new environments may be heavily influenced by the composition of their gastrointestinal microbe fauna, which is fundamentally important to animal health. Siganus fuscescens thus provides an opportunity to assess the stability of gastrointestinal microbes under varying environmental conditions. The gastrointestinal microbial communities of S. fuscescens were characterized over 2,000 km of Australia’s western coast, from tropical to temperate waters, including near its current southern distributional limit. Sequencing of the 16S rRNA gene demonstrated that each population had a distinct hindgut microbial community, and yet, 20 OTUs occurred consistently in all samples. These OTUs were considered the ‘core microbiome’ and were highly abundant, composing between 31 and 54% of each population. Furthermore, levels of short chain fatty acids, an indicator of microbial fermentation activity, were similar among tropical and temperate locations. These data suggest that flexibility in the hindgut microbiome may play a role in enabling such herbivores to colonize new environments beyond their existing range. [ABSTRACT FROM AUTHOR]

Dietary products with prebiotic properties have been used to promote protective effects during inflammatory process. Prebiotics are source of short chain fatty acids (SCFAs) that have been associated with anti-inflammatory effects. Banana ( Musa sp. AAA) is rich in resistant starch, which is used by colonic microbiota to SCFAs production. For this, we used the trinitrobenzenesulphonic acid model of intestinal inflammation to evaluate whether intestinal anti-inflammatory effect is related to prebiotic effects. Dietary intervention with green dwarf banana flour (5% or 10%) increased acetate, propionate and butyrate concentration. The protective effects was also evidenced by reduction in extension of lesion, inhibition of myeloperoxidase activity, prevention in glutathione depletion, increased mucin production and mucosal healing. This way, dietary green dwarf banana modulates oxidative stress and colonic production of SCFAs increasing intestinal tissue protection and may be used as a complementary product to prevent or avoid relapse of symptoms in inflammatory bowel diseases. [ABSTRACT FROM AUTHOR]

Vacuum ultraviolet (VUV) absorption spectroscopy was recently introduced as a new detection system for one, as well as comprehensive two-dimensional gas chromatography (GC×GC) and successfully applied to the analysis of various analytes in several matrices. In this study, its suitability for the analysis of breath metabolites was investigated and the impact of a finite volume of the absorption cell and makeup gas pressure was evaluated for volatile analytes in terms of sensitivity and chromatographic resolution. A commercial available VUV absorption spectrometer was coupled to GC×GC and applied to the analysis of highly polar volatile organic compounds (VOCs). Breath gas samples were acquired by needle trap micro extraction (NTME) during a glucose challenge and analysed by the applied technique. Regarding qualitative and quantitative information, the VGA-100 is compatible with common GC×GC detection systems like FID and even TOFMS. Average peak widths of 300 ms and LODs in the lower ng range were achieved using GC×GC-VUV. Especially small oxygenated breath metabolites show intense and characteristic absorption patterns in the VUV region. Challenge responsive VOCs could be identified and monitored during a glucose challenge. The new VUV detection technology might especially be of benefit for applications in clinical research. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work was to investigate the catabolic process of three kinds of dietary carbohydrates in the gut of sea bass juveniles, with the possible contribution of the intestinal microbiota to the nutrition of the host, and the subsequent effects on intermediary metabolism. A first diet contained waxy maize (99% amylopectin), a highly digestible form of starch. A second diet was less quickly digestible due to its high amylose content of resistant starch. Two other diets contained fibre instead of starch, either only cellulose as control, or also other non-starch polysaccharides brought by lupin meal. The effect of the diets on the host confirmed previous results, with the stimulation of glucose storage in the liver in sea bass fed the starchy diets, which caused a significant increase in liver weight, while lupin meal caused an increase in visceral mass. Glycaemia was higher 7±1h after the last meal in the group fed resistant starch, compared to the other dietary groups, while the fast digestion of waxy maize resulted already in hypertriglyceridemia, possibly due to hepatic neolipogenesis. At the same sampling time, the activity of free amylase was reduced in the intestine of sea bass fed resistant starch, but maltase activity was stimulated in the brush border membranes of enterocytes in the same group, confirming thus the timely digestion of resistant starch. Hepatic mRNA transcripts indicated that glucose metabolism was oriented towards neoglucogenesis by the high-fibre diets, and towards glucose storage by the starchy diets, especially with waxy maize. The diet influenced both faecal and mucosal microbiota, though in different ways, likely due to the interaction with the host. Lupin meal seemed potentially interesting as a source of prebiotic polysaccharides, by modifying the balance between Vibrio spp. and Clostridium sp. Both forms of starch were also partly metabolised by microbiota, resulting in an increased concentration of acetate in the faeces. [Copyright &y& Elsevier]

Abstract: The interest in the study of the effect of endosperm vitreousness (VT) on the nutritive value of maize is increasing in pig nutrition. Therefore, an experiment was conducted to determine the effect of maize VT on starch digestion, resistant starch (RS) content, dry matter digestibility as well as on large intestine fermentation kinetics and related end products by using several in vitro techniques specifically designed for pigs. A set of 30 maize grains was selected to represent a wide range of VT (as a proportion of vitreous in total endosperm) determined by a manual dissection method. Five distinct VT classes were designed [very low (vlVT), low (lVT), medium (mVT), high (hVT) and very high (vhVT)] and identified by a specific VT value (i.e., 291, 357, 432, 611 and 830g/kg endosperm, respectively), calculated as the mean of VT values of maize samples entering the specific class. Starch digestion (expressed as predicted glycemic index) and the rate of starch digestion decreased linearly (ranging from 42.5 to 14.5 and from 0.018 to 0.006/min respectively, for vlVT and vhVT; P<0.05), whereas RS increased linearly (from 183 to 381g/kg dry matter; P<0.05) with VT classes. The total tract in vitro dry matter digestibility decreased linearly (from 0.96 to 0.75; P<0.05) with VT classes. The in vitro fermentation showed that the rate of fermentation decreased (from 0.060 to 0.044/h; P<0.05), whereas the total short chain fatty acid (SCFA) production increased (ranging from 6.29 to 7.29mmol/g dry matter incubated; P<0.05) linearly with VT classes. The molar ratio of acetate linearly increased, ranging from 0.50 to 0.55 (P<0.05) with VT classes, whereas no differences were observed for other individual SCFA. The loading plot of principal component analysis revealed significant relationships between VT and variables of interest. Results indicated that VT promoted marked effects on in vitro parameters related to starch and dry matter digestibility and fermentable kinetics for pigs. Further in vivo validations are required to validate these findings. [Copyright &y& Elsevier]

Abstract: The prebiotic lactulose, a probiotic strain of Lactobacillus plantarum (L. plantarum) and a synbiotic combination of these two agents were evaluated as growth promoters in 25–39-day old commercial weaning pigs. Ninety-six weaning pigs were allocated into 32 pens, taking initial weight into account, and distributed into four groups as follows: a control diet (CTR), the same diet supplemented daily with L. plantarum (109 CFU/mL sprayed on top; 20mL/pig) (LPN); 10g/kg lactulose (LAC) or a combination of both treatments (SYN). At day 14, eight piglets from each group were euthanized and proximal colon digesta was sampled for luminal pH, short-chain fatty acids (SCFA) and lactic acid concentrations. Deoxyribonucleic acid was extracted from colonic digesta and the microbial community was profiled by terminal restriction fragment length polymorphism analysis (T-RFLP) and qPCR. Blood urea nitrogen (BUN) and acute-phase proteins (Pig-MAP) were measured. Lactulose treatment (LAC) improved feed intake (P<0.05), average daily gain (P<0.01), feed:gain ratio (P<0.05) and reduced BUN (P<0.01). Both, LAC and LPN treatment, decreased the Enterobacteriaceae:Lactobacillus spp. ratio in the colonic luminal contents (P<0.05). Moreover LPN treatment promoted a decrease in the percentage of branched fatty acids (P<0.01) suggesting a reduction in proteolytic microbial activity. Microbial profiling of colonic luminal contents by T-RFLP revealed changes in some microbial species. Terminal restriction fragments (TRFs) compatible with Bifidobacterium thermoacidophilum were more frequently detected in experimental diets compared to CTR (P<0.05). Pigs receiving SYN diet demonstrated the combined positive effects of individual LAC and LPN treatment although we were not able to show a specific increase in the probiotic strain with the inclusion of lactulose. Collectively, these data suggest the combination of lactulose and L. plantarum acts as a complementary synbiotic, but not as a synergistic combination. [Copyright &y& Elsevier]

Abstract: We investigated the biotransformation of four common dietary polyphenols, rutin, quercetin, chlorogenic acid and caffeic acid, in an in vitro mixed culture model of human intestinal microbiota, to determine effects on human gut bacteria. All four compounds were biotransformed rapidly, disappearing from the medium within 0.5 h and later replaced by known phenolic acid breakdown products, at concentrations up to hundreds of micromolar, much higher than in no-polyphenol control experiments. Quantitative PCR was used to measure effects of the polyphenols on the balance between the major groups of intestinal bacteria that are known to influence gut health, i.e., Bifidobacterium spp., Bacteroidetes, and Firmicutes. Fermentation of polyphenols stimulated proliferation of bifidobacteria and decreased the ratio of Firmicutes to Bacteroidetes, relative to controls. Polyphenols also stimulated short chain fatty acid production by the bacteria. Pure bifidobacterial cultures were treated separately with either fermented media isolated from the incubations, the pure test polyphenols, or the biotransformation products detected in the fermentations. Growth stimulation was observed only with fermented polyphenol media and the pure biotransformation products. It appears that dietary polyphenols may have the ability to modify the gut microbial balance, but this effect is indirect, i.e., it is mediated by biotransformation products, rather than the original plant compounds. [Copyright &y& Elsevier]

Bran is a good source of dietary fibre, phytochemicals, and also protein, but highly insoluble and recalcitrant structure of bran hinders accessibility of these components for gastrointestinal digestion. In the present work, influence of bioprocessing on the microstructure and chemical properties of rye bran and wheat bread fortified with the rye bran were studied. In vitro protein digestibility, and release of short chain fatty acids (SCFA) and ferulic acid in a gut model were studied. Bioprocessing of rye bran was performed with subsequent treatments with cell-wall hydrolysing enzymes (40 °C, 4 h) and yeast fermentation (20 °C, 20 h). Bioprocessing of rye bran resulted in reduced total dietary fibre content, caused mainly by degradation of fructan and β-glucan, and increased soluble fibre content, caused mainly by solubilisation of arabinoxylans. Microscopic analysis revealed degradation of aleurone cell wall structure of the bioprocessed rye bran. Bioprocessing caused release of protein from aleurone cells, assessed as a larger content of soluble protein in bran and a higher hydrolysis rate in vitro. Bioprocessed bran had also faster SCFA formation and ferulic acid release in the colon fermentation in vitro as compared to native bran. [ABSTRACT FROM AUTHOR]

Abstract: This study was carried out to determine the influence of short chain fatty acids (SCFA) on spleen and mesenteric lymph node lymphocyte proliferation, goblet cells and apoptosis in the mouse small intestine during invasion by Trichinella spiralis. BALB/c mice were infected with 250 larvae of T. spiralis. An SCFA water solution containing acetic, propionic and butyric acids (30:15:20mM) was administered orally starting 5days before infection and ending 20days post infection (dpi). Fragments of the jejunum were collected by dissection 7 and 10dpi, and were examined for apoptotic cells in the lamina propria of the intestinal mucosa, and for goblet cells. The proliferation index of the cultured spleen and mesenteric lymph node lymphocytes with MTT test was also determined. The orally administered SCFA solution decreased the proliferation of mesenteric lymph node lymphocytes in the mice infected with T. spiralis at both examination times, but did not influence the proliferative activity of the spleen cells. Seven dpi, both in the spleen and mesenteric lymph nodes, the highest proliferation index of concanavalin A (Con A)-stimulated lymphocytes was found in the group of uninfected animals receiving SCFA animals. This tendency could still be seen 10dpi in the mesenteric lymph nodes but not in the spleen, where the proliferation index in this group had significantly decreased. In vitro studies revealed, that butyric and propionic acids added to the cell cultures suppressed the proliferation of Con A-stimulated mesenteric lymph nodes and spleen lymphocytes taken from uninfected and T. spiralis-infected mice. Acetic acid stimulated proliferation of splenocytes taken from uninfected mice but did not affect lymphocyte proliferation in mesenteric lymph nodes from uninfected or infected mice. Orally administered SCFA increased the number of goblet cells found in the epithelium of the jejunum 7dpi, but this number had decreased 10dpi. The number of apoptotic cells in the lamina propria of the intestinal mucosa of animals infected with the T. spiralis and receiving SCFA was also lower, particularly 10dpi. The above results show that SCFA can participate in the immune response during the course of trichinellosis in mice. [Copyright &y& Elsevier]

Guava fruit is rich in phenolic compounds (PCs), whose metabolic fate has not been explored. Non-digestible carbohydrates and PCs in whole guava (WG) and seedless guava (SG) were submitted to an in vitro colonic fermentation, followed by evaluation of the anti-proliferative activity of the fermentation extracts in HT-29 cancer cell lines. The main PCs in both samples were (+)-gallocatechin and gallic acid, while procyanidin B was the most abundant one associated with soluble indigestible fraction and quercetin predominated in the insoluble indigestible fraction. The fermentability index at 24 h was 78.84% in WG and 84.74% for SG, near to the value for raffinose used as reference, with butyric acid as the main short chain fatty acids (SCFA) produced. The greatest antiproliferative effects were observed in the SG at 12 h of fermentation and WG at 24 h of fermentation. These results allow to suggest consumption of guava fruit, either with or without seeds, as a feasible way to maintain colonic health. • Whole guava (WG) and seedless guava (SG) metabolic fate has been explored. • Quercertin was the most abundant in the insoluble indigestible fraction in WG and SG. • Fermentability index at 24 h was 78.84% in WG and 84.74% for SG. • Butyric acid was the main short chain fatty acid produced. • Antiproliferative effects were observed in the SG-12 h and WG-24 h groups. [ABSTRACT FROM AUTHOR]

The partial degradation of β-glucans and arabinoxylans in cereal-based diets by specific enzymes may improve the nutritional value for the pig. Therefore, the aim of the present study was to examine the influence of diets with different contents of cereal non-starch polysaccharides (NSP) without or with supplementation of the enzymes endo-(1-3),(1-4)-β-glucanase and endo-(1-4)-β-xylanase on digestibility and gut environment. A total of 32 male castrated (Y × L) piglets from eight litters was allocated to a diet high in NSP (H) or low in NSP (L), each diet without and with enzyme supplementation (1 g/kg diet each of β-glucanase and β-xylanase). Diet H contained 874 g cereals and 197 g NSP/kg DM and was composed of triticale:wheat bran:oats:wheat:barley in relative proportions of 0.367:0.341:0.143:0.120:0.029. Diet L contained 433 g cereals and 106 g NSP/kg DM and the cereal part was composed of triticale:wheat bran:oats:barley:wheat in relative proportions of 0.432:0.360:0.120:0.048:0.039. The trial started before weaning when the piglets were aged 27–28 days (live weight 8.9±0.6 kg). After 14 days on the respective diets (mean live weight 11.6±1.3 kg) the piglets were euthanised and digesta samples collected from the gastro-intestinal tract. The high NSP level resulted in increased daily gain (P < 0.05), decreased digestibility (P < 0.05) of organic matter in the ileum, caecum, colon and rectum, decreased pH (P < 0.05) in the caecum and colon and increased content (P < 0.05) of total organic acids (OA) in the stomach and ileum. Furthermore, the high NSP level resulted in an increased (P < 0.05) molar proportion of lactic acid (of total OA) in the stomach and ileum and an increased (P < 0.05) molar proportion of propionic and butyric acid (of short chain fatty acids, SCFA) in the ileum. Enzyme supplementation increased (P < 0.05) the molar proportion of lactic acid (of total OA) in the ileum and decreased (P < 0.05) the molar proportion of acetic acid (of SCFA) in the ileum.In conclusion, dietary NSP level influenced the digestibility of organic matter, as well as the gut environment. However, the digestibility of dietary fibre components was unaffected by NSP level. An increased dietary content of NSP and supplementation with fibre degrading enzymes influenced the distribution of OA in the ileum, indicating a shift in dominating bacteria. [Copyright &y& Elsevier]

We investigated the chemoprotective effects of four common constituents of the human diet, i.e. a fermented milk, inulin, oligofructose and Brussels sprouts, towards 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-induced genotoxicity in male Fischer 344 rats harbouring a human intestinal microflora. We found that the four dietary components significantly reduced IQ-induced DNA damage in hepatocytes (reduction ranged from 74% with inulin to 39% with Brussels sprouts) and colonocytes (reduction ranged from 68% with inulin to 56% with Brussels sprouts). This chemoprotective effect correlated with the induction of hepatic UDP-glucuronosyl transferase following Brussels sprouts consumption, and with alterations of bacterial metabolism in the distal gut (acidification, increase of butyrate proportion, decrease of β-glucuronidase activity) following inulin consumption. [Copyright &y& Elsevier]

With the objective of restoring the low zinc bioavailability of phytate-containing diets, cellulose was replaced by pectin, alginic acid, carrageenan, chitosan or raw potato starch (RS), in phytate-free and phytate-containing diets, and given to rats for 21 days. Feeding chitosan, alginic acid or RS (200 g/kg) as the dietary fiber polysaccharide lessened the deleterious effect of phytate, increasing zinc apparent absorption (excluding RS), femur zinc concentration and growth, compared to rats fed cellulose or fiber-free diets. Feeding pectin, alginic acid, chitosan or RS (200 g/kg) lowered cecal pH and increased cecal content weight. Chitosan, alginic acid and RS increased femur zinc concentration when fed to rats in phytate-containing diets, while RS was also effective in phytate-free diets. Therefore, chitosan and alginic acid might enhance zinc bioavailability through a different mechanism from that of RS. Feeding chitosan, alginic acid or raw potato starch lessens the inhibitory effect of phytic acid on zinc bioavailability. [Copyright &y& Elsevier]