Comparison of different fibers for in vitro production of short chain fatty acids by intestinal microflora

Changes in Digestive Health, Satiety and Overall Well-Being after 14 Days of a Multi-Functional GI Primer Supplement

A recent review proposed a role for multi-functional food or supplement products in priming the gut to support both digestive and systemic health. Accordingly, we designed and eva-luated the effect of a multi-functional gastrointestinal (GI) primer supplement on participant-reported measures for digestive health, quality-of-life (e.g., energy/vitality and general health), and reasons for satiation (e.g., attitudes towards food and eating). In this single-arm clinical trial, 68 participants with mild digestive symptoms consumed the GI primer supplement daily for 14 days. Digestive symptoms were evaluated daily from baseline (Day 0) through Day 14. At baseline and Day 14, participants reported their stool consistency, reasons for satiation, and quality-of-life measures using validated questionnaires. At Day 14, participants reported significant improvements in all (13/13) digestive symptom parameters (p-values < 0.05) and an increase in % of stools with normal consistencies. There were significant improvements (p-values < 0.05) in energy/vitality and general health, and in specific attitudes towards food and eating (e.g., physical satisfaction, planned amount, decreased eating priority, decreased food appeal, and self-consciousness). Results suggest the GI primer supplement promotes digestive health, improves quality of life, and impacts attitudes towards food/eating. This study provides preliminary support for the gut priming hypothesis through which multi-functional digestive products may improve GI health.

Antitumor properties of traditional lactic acid bacteria: Short-chain fatty acid production and interleukin 12 induction

This paper presents an in vitro evaluation of antitumor properties through producing short-chain fatty acids and inducing interleukin 12. In addition, it offers the most important and functional probiotic properties of 24 Lactobacillus gasseri, Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Limosilactobacillus fermentum strains isolated from humans, foods, and fermented foods. To this end, survival in an acidic environment (pH = 2.5), tolerance in bile salt, viability in the presence of pepsin-pancreatin, adhesion percentage, antibiotic resistance, auto-aggregation, and potential percentage of co-aggregation are studied in contact with three human intestinal pathogens. These pathogens are Escherichia coli O157: H7 NCTC 12900, Salmonella enterica subsp. enterica ATCC 13076, and Listeria monocytogenes ATTC 7644. Also, in vitro induction amount of IL-12 in mouse splenocytes is investigated to evaluate antitumor properties by 19 strains of L. gasseri and L. plantarum along with the development of short-chain fatty acids (SCFA) by 5 strains of L. fermentum and L. acidophilus. Gas Chromatography Flame Ionization Detector (GC-FID) and enzyme-linked immunosorbent assay (ELISA) were used to measure short-chain fatty acids and IL-12, respectively. All strains had high viability under acidic conditions. The highest levels of pancreatin and pepsin resistance were found in strains LF56, LF57, LF55, OF, and F and strains LF56, LF57, and A7, respectively. All strains except LF56 had high resistance to bile salts. L. gasseri 54C had the highest average adhesion score (hydrophobicity) of 62.9 % among 19 strains. Despite the susceptibility of different strains of L. plantarum to the tested antibiotics, M8 and M11, S2G, A7, LF55, LF57, and 5G were resistant to kanamycin and chloramphenicol, respectively. Also, 21G was resistant to ampicillin, LF56 to tetracycline and M8, and M11, LF56, and 21G to Erythromycin. In addition, L. gasseri showed moderate resistance to ampicillin, erythromycin, and tetracycline, while L. fermentum ATCC 9338 showed good resistance to ampicillin, erythromycin, and chloramphenicol. In this respect, L. plantarum LF56 and gasseri 54C had the highest average auto-aggregation and co-aggregation against three pathogenic bacteria, respectively. The highest and lowest levels of acetic acid as short-chain fatty acids were produced by L. fermentum 19SH isolated from Horre 41.62 and L. fermentum 21SH from fermented seeds 27.047, respectively. Moreover, L. fermentum, with the OF code of traditional-fermented food origin, produced the most isobutyric acid, butyric acid, and valeric acid, with values of 0.6828, 0.74165, and 0.49915 mmol, respectively. L. fermentum isolated from the human origin with code F produced the most isovaleric acid of 1.1874 mmol. All the tested strains produced good propionic acid except L. fermentum 21SH from fermented seeds. Among strains, L. plantarum M11 isolated from milk and L. gasseri 52B from humans had the highest in vitro induction of IL-12, which is probably related to their cell wall compositions and structure.

Effects of sex on fat deposition through gut microbiota and short-chain fatty acids in weaned pigs

Nitrogen pollution resulting from excessive feed consumption poses a significant challenge for modern swine production. Precision nutrition technology seems to be an effective way to solve this problem; therefore, understanding the law of pig body composition deposition is a prerequisite. This study investigated the sex effects on growth performance, body composition, nutrient deposition, gut microbiota, and short-chain fatty acids (SCFA) in weaned piglets. Eighty weaned pigs were randomly allocated to 2 treatments according to the sex of pigs. An individual pig was considered as a treatment replicate. Six body weights (BW 5, 7, 11, 15, 20, and 25 kg) were chosen as experimental points; for each point 10 piglets close to the average BW (5 males and 5 females) were slaughtered, and there was one growth phase between each 2 BW points. Results indicated that the males had higher average daily gain (ADG) and average daily feed intake (ADFI) compared to the females (P < 0.05) at growth phases 15 to 20 kg BW and 20 to 25 kg BW. Meanwhile, males at 20 kg BW had higher body fat content than females (P < 0.10). Males showed a higher body fat (P < 0.05) deposition rate at phase 15 to 20 kg BW (P < 0.05) than females. For pigs at 20 kg BW, the relative abundance of RuminococcaceaeUCG-005, Clostridium, Christensenellaceae_R-7_group, and Peptostreptococcaceae was significantly increased in males (P < 0.05) but that of Bifidobacterium was decreased (P < 0.05). At 25 kg BW, the relative abundance of Ruminococcaceae_NK4A214_group, Fibrobacter, RuminococcaceaeUCG-009, Ralstonia, Klebsiel, and Christensenellaceae_R-7_group in males was higher when compared with females (P < 0.05). In terms of SCFA, females exhibited higher concentrations of propionate compared to males (P < 0.05). The results of the current study indicated that sex influenced fat deposition through changes in the composition of gut microbiota and the content of SCFA, which has significant implications for the realization of precision nutrition in modern swine production.

Intervention effects of low-molecular-weight chondroitin sulfate from the nasal cartilage of yellow cattle on lipopolysaccharide-induced behavioral disorders: regulation of the microbiome-gut-brain axis

Chondroitin sulfate (CS) is a sulfated linear polysaccharide with different functional activities, including antioxidant, anti-inflammatory, lipid-lowering, and immune regulation. As natural sulfated polysaccharides have high molecular weight, high apparent viscosity, low water solubility, complex structure, and high negative charge, they have difficulty binding to receptors within cells across tissue barriers, resulting in low bioavailability and unclear structure-activity relationships. In this study, an H2O2-Vc oxidative degradation system was employed to perform environmentally friendly and controllable degradation of CS extracted from the nasal cartilage of Shaanxi Yellow cattle. Two low-molecular-weight chondroitin sulfates (LMWCSs), CS-1 (14.8 kDa) and CS-2 (50.9 kDa), that exhibit strong in vitro free radical scavenging ability were obtained, and their structures were characterized. Mice intraperitoneally administered lipopolysaccharide (LPS) were used to explore the cognitive intervention effects of LMWCS. Supplementing CS-1 and CS-2 significantly downregulated the levels of the serum inflammatory factors, TNF-α and IL-1β, promoted the expression of GSH in the brain, and inhibited the production of the lipid peroxidation product, malondialdehyde (MDA), ultimately inhibiting LPS-induced cognitive impairment in mice. Surprisingly, compared to the LPS model group, the abundances of Streptococcus, Eisenbergiella, Vampirovibrio, Coprococcus, Enterococcus and Lachnoanaerobaculum were significantly increased in the intestines of mice in the CS-1 and CS-2 group, whereas those of Parabacteroides and Mycoplasma were significantly decreased. Altogether, this study provides a theoretical basis for the comprehensive utilization of agricultural and animal resources and the application of brain nutrition, anti-inflammatory, and LMWCS health products.

Short-Chain Fatty Acids and Human Health: From Metabolic Pathways to Current Therapeutic Implications

The gastrointestinal tract is home to trillions of diverse microorganisms collectively known as the gut microbiota, which play a pivotal role in breaking down undigested foods, such as dietary fibers. Through the fermentation of these food components, short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate are produced, offering numerous health benefits to the host. The production and absorption of these SCFAs occur through various mechanisms within the human intestine, contingent upon the types of dietary fibers reaching the gut and the specific microorganisms engaged in fermentation. Medical literature extensively documents the supplementation of SCFAs, particularly butyrate, in the treatment of gastrointestinal, metabolic, cardiovascular, and gut-brain-related disorders. This review seeks to provide an overview of the dynamics involved in the production and absorption of acetate, propionate, and butyrate within the human gut. Additionally, it will focus on the pivotal roles these SCFAs play in promoting gastrointestinal and metabolic health, as well as their current therapeutic implications.

Effectiveness of Partially Hydrolyzed Guar Gum on Cognitive Function and Sleep Efficiency in Healthy Elderly Subjects in a Randomized, Double-Blind, Placebo-Controlled, and Parallel-Group Study

The consumption of functional foods in a daily diet is a promising approach for the maintenance of cognitive health. The present study examines the effects of water-soluble prebiotic dietary-fiber, partially hydrolyzed guar gum (PHGG), on cognitive function and mental health in healthy elderly individuals. Participants consumed either 5 g/day of PHGG or a placebo daily for 12 weeks in this randomized, double-blind, placebo-controlled, and parallel-group study. An assessment of cognitive functions, sleep quality, and subjective mood evaluations was performed at baseline and after 8 and 12 weeks of either PHGG or placebo intake. The visual memory scores in cognitive function tests and sleepiness on rising scores related to sleep quality were significantly improved in the PHGG group compared to the placebo group. No significant differences were observed in mood parameters between the groups. Vigor-activity scores were significantly improved, while the scores for Confusion-Bewilderment decreased significantly in the PHGG group when compared to the baseline. In summary, supplementation with PHGG was effective in improving cognitive functions, particularly visual memory, as well as enhancing sleep quality and vitality in healthy elderly individuals (UMIN000049070).

In vitro digestion and colonic fermentation of phenolic compounds and their antioxidant potential in Australian beach-cast seaweeds

Beach-cast seaweed has recently garnered attention for its nutrient-rich composition, including proteins, carbohydrates, vitamins, minerals, and phytochemicals. This study focuses on the phenolic content and antioxidant potential of five Australian beach-cast seaweed species during in vitro digestion and colonic fermentation. The bioaccessibility of the selected phenolic compounds was estimated and short chain fatty acids (SCFAs) production was determined. Cystophora sp., showed a notable increase in phenolic content (23.1 mg GAE/g) and antioxidant capacity (0.42 mg CE/g) during the intestinal and gastric phases of in vitro digestion. Durvillaea sp. demonstrated a significant release of flavonoids (0.35 mg QE/g), while Phyllosphora comosa released high levels of tannins (0.72 mg CE/g) during the intestinal phase. During colonic fermentation, P. comosa released the highest levels of phenolic compounds (4.3 mg GAE/g) after 2 h, followed by an increase in flavonoids (0.15 mg QE/g), tannins (0.07 mg CE/g), and antioxidant activity (DPPH: 0.12 mg CE/g; FRAP: 0.61 mg CE/g) after 4 h. Moreover, P. comosa released a considerable amount of phenolic compounds during both in vitro digestion and colonic fermentation. All species consistently released phenolic compounds throughout the study. Phloroglucinol, gallic acid, and protocatechuic acid were identified as the most bioaccessible phenolic compounds in all five Australian beach-cast seaweeds in the in vitro digestion. Nevertheless, compound levels declined during the colonic fermentation phase due to decomposition and fermentation by gut microbiota. With regard to SCFAs, P. comosa displayed elevated levels of acetic (0.51 mmol/L) and propionic acid (0.36 mmol/L) at 2 h, while Durvillaea sp. showed increased butyric (0.42 mmol/L) and valeric (0.26 mmol/L) production acid after 8 h. These findings suggest that seaweed such as Cystophora sp., Durvillaea sp., and P. comosa are promising candidates for food fortification or nutraceutical applications, given their rich phenolic content and antioxidant properties that potentially offer gut health benefits.

Dietary Fibre for the Prevention of Post-Pancreatitis Diabetes Mellitus: A Review of the Literature and Future Research Directions

Post-pancreatitis diabetes mellitus-the most common sequela of pancreatitis-leads to poorer glycaemic control compared with type 2 diabetes. Because post-pancreatitis diabetes mellitus is an exemplar of secondary diabetes (with a clear underlying cause), much post-pancreatitis diabetes mellitus is preventable or treatable early. Earlier literature established the important role of dietary fibre in reducing plasma glucose in individuals with type 2 diabetes. The present review benchmarks available evidence on the role of habitual dietary fibre intake in pancreatitis and post-pancreatitis diabetes mellitus. It also paves the way for future research on the use of dietary fibre in the post-pancreatitis setting.

The molecular mechanism of polysaccharides in combating major depressive disorder: A comprehensive review

Major depressive disorder (MDD) is a complex psychiatric condition with diverse etiological factors. Typical pathological features include decreased cerebral cortex, subcortical structures, and grey matter volumes, as well as monoamine transmitter dysregulation. Although medications exist to treat MDD, unmet needs persist due to limited efficacy, induced side effects, and relapse upon drug withdrawal. Polysaccharides offer promising new therapies for MDD, demonstrating antidepressant effects with minimal side effects and multiple targets. These include neurotransmitter, neurotrophin, neuroinflammation, hypothalamic-pituitary-adrenal axis, mitochondrial function, oxidative stress, and intestinal flora regulation. This review explores the latest advancements in understanding the pharmacological actions and mechanisms of polysaccharides in treating major depression. We discuss the impact of polysaccharides' diverse structures and properties on their pharmacological actions, aiming to inspire new research directions and facilitate the discovery of novel anti-depressive drugs.

Nutritional regulation of microbiota-derived metabolites: Implications for immunity and inflammation

Nutrition profoundly shapes immunity and inflammation across the lifespan of mammals, from pre- and post-natal periods to later life. Emerging insights into diet-microbiota interactions indicate that nutrition has a dominant influence on the composition-and metabolic output-of the intestinal microbiota, which in turn has major consequences for host immunity and inflammation. Here, we discuss recent findings that support the concept that dietary effects on microbiota-derived metabolites potently alter immune responses in health and disease. We discuss how specific dietary components and metabolites can be either pro-inflammatory or anti-inflammatory in a context- and tissue-dependent manner during infection, chronic inflammation, and cancer. Together, these studies emphasize the influence of diet-microbiota crosstalk on immune regulation that will have a significant impact on precision nutrition approaches and therapeutic interventions for managing inflammation, infection, and cancer immunotherapy.

The health benefits of dietary short-chain fatty acids in metabolic diseases

Short-chain fatty acids (SCFAs) are a subset of fatty acids that play crucial roles in maintaining normal physiology and developing metabolic diseases, such as obesity, diabetes, cardiovascular disease, and liver disease. Even though dairy products and vegetable oils are the direct dietary sources of SCFAs, their quantities are highly restricted. SCFAs are produced indirectly through microbial fermentation of fibers. The biological roles of SCFAs in human health and metabolic diseases are mainly due to their receptors, GPR41 and GPR43, FFAR2 and FFAR3. Additionally, it has been demonstrated that SCFAs modulate DNMTs and HDAC activities, inhibit NF-κB-STAT signaling, and regulate G(i/o)βγ-PLC-PKC-PTEN signaling and PPARγ-UCP2-AMPK autophagic signaling, thus mitigating metabolic diseases. Recent studies have uncovered that SCFAs play crucial roles in epigenetic modifications of DNAs, RNAs, and post-translational modifications of proteins, which are critical regulators of metabolic health and diseases. At the same time, dietary recommendations for the purpose of SCFAs have been proposed. The objective of the review is to summarize the most recent research on the role of dietary SCFAs in metabolic diseases, especially the signal transduction of SCFAs in metabolic diseases and their functional efficacy in different backgrounds and models of metabolic diseases, at the same time, to provide dietary and nutritional recommendations for using SCFAs as food ingredients to prevent metabolic diseases.

Roles of Short-Chain Fatty Acids in Inflammatory Bowel Disease

The gut microbiome is a diverse bacterial community in the human gastrointestinal tract that plays important roles in a variety of biological processes. Short-chain fatty acids (SCFA) are produced through fermentation of dietary fiber. Certain microbes in the gut are responsible for producing SCFAs such as acetate, propionate and butyrate. An imbalance in gut microbiome diversity can lead to metabolic disorders and inflammation-related diseases. Changes in SCFA levels and associated microbiota were observed in IBD, suggesting an association between SCFAs and disease. The gut microbiota and SCFAs affect reactive oxygen species (ROS) associated with IBD. Gut microbes and SCFAs are closely related to IBD, and it is important to study them further.

Dietary Fiber and Its Potential Role in Obesity: A Focus on Modulating the Gut Microbiota

Dietary fiber is a carbohydrate polymer with ten or more monomeric units that are resistant to digestion by human digestive enzymes, and it has gained widespread attention due to its significant role in health improvement through regulating gut microbiota. In this review, we summarized the interaction between dietary fiber, gut microbiota, and obesity, and the beneficial effects of dietary fiber on obesity through the modulation of microbiota, such as modifying selective microbial composition, producing starch-degrading enzymes, improving gut barrier function, reducing the inflammatory response, reducing trimethylamine N-oxide, and promoting the production of gut microbial metabolites (e.g., short chain fatty acids, bile acids, ferulic acid, and succinate). In addition, factors affecting the gut microbiota composition and metabolites by dietary fiber (length of the chain, monosaccharide composition, glycosidic bonds) were also concluded. Moreover, strategies for enhancing the biological activity of dietary fiber (fermentation technology, ultrasonic modification, nanotechnology, and microfluidization) were subsequently discussed. This review may provide clues for deeply exploring the structure-activity relationship between dietary fiber and antiobesity properties by targeting specific gut microbiota.

Partially Hydrolyzed Guar Gum Intake Supports the Gut Microbiota and Attenuates Inflammation during Influenza H1N1 Virus Infection in Mice

Partially hydrolyzed guar gum (PHGG) is a soluble dietary fiber that is effective for defecation control. It influences the gut microbiota, by which it is metabolized to yield short-chain fatty acids (SCFAs), and it was also recently shown to protect against influenza infection in humans. We here investigated the effects of PHGG in a mouse model of influenza H1N1 virus infection. Eight-week-old C57BL/6 mice were fed normal chow with or without PHGG (500 mg/kg per day) for 4 weeks, infected with H1N1 at 10 weeks of age, and analyzed at 12 weeks of age. Administration of PHGG attenuated the decline in body weight induced by H1N1 infection without affecting food intake. It also ameliorated intestinal atrophy and increased the production of SCFAs including acetic acid, propionic acid, and butyric acid in the cecum, thereby preventing the inhibitory effect of H1N1 infection on SCFA production. The H1N1-induced increases in the serum concentrations of inflammatory cytokines including interferon-γ and interleukin-6 and anti-inflammatory cytokine such as interleukin-10 were all inhibited by PHGG intake. In addition, PHGG administration attenuated inflammatory gene expression in the lung and promoted both natural killer cell activity and regulatory T-cell differentiation in the spleen. Our findings suggest that the consumption of PHGG may improve the gut environment and thereby limit the inflammatory response to H1N1 infection. They may thus provide the basis for novel dietary intervention strategies to suppress the excessive inflammation associated with virus infection.

The impact of antimicrobial food additives and sweeteners on the growth and metabolite production of gut bacteria

Metabolic disorders caused by the imbalance of gut microbiota have been associated with the consumption of processed foods. Thus, this study aimed to evaluate the effects of antimicrobial food additives (benzoate, sorbate, nitrite, and bisulfite) and sweeteners (saccharin, stevia, sucralose, aspartame, and cyclamate) on the growth and metabolism of some gut and potentially probiotic bacterial species. The effects on the growth of Bifidobacterium longum, Enterococcus faecium, Lactobacillus acidophilus, and Lactococcus lactis subsp. lactis cultures were investigated using a turbidimetric test and by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). To evaluate the metabolic activity, the cultures were exposed to compounds with the highest antimicrobial activity, subjected to cultivation with inulin (1.5%), and analyzed by liquid chromatography for the production of short-chain fatty acids (acetate, propionate, and butyrate). The results showed that potassium sorbate (25 mg/mL), sodium bisulfite (0.7 mg/mL), sodium benzoate, and saccharin (5 mg/mL) presented greater antimicrobial activity against the studied species. L. lactis and L. acidophilus bacteria had reduced short-chain fatty acid production after exposure to saccharin and sorbate, and B. longum after exposure to sorbate, in comparison to controls (acetic acid reduction 1387 μg/mL and propionic 23 μg/mL p < 0.05).

Auricularia auricula-judae (Bull.) polysaccharides improve obesity in mice by regulating gut microbiota and TLR4/JNK signaling pathway

Obesity has emerged as a crucial factor impacting people's lives, and gut microbiota disorders contribute to its development and progression. Auricularia auricula-judae (Bull.) polysaccharides (AAPs), a traditional functional food in Asia, exhibit potential anti-obesity effects. However, the specific mechanism still needs to be further confirmed. This study investigated the beneficial effects and specific mechanisms of AAPs on obesity. Firstly, AAPs showed significant improvements in overweight, insulin resistance, glucose and lipid metabolism disorders, and liver damage in obese mice. Additionally, AAPs ameliorated gut microbiota disorders, promoting the proliferation of beneficial bacteria like Lactobacillus and Roseburia, resulting in increased levels of SCFAs, folate, and cobalamin. Simultaneously, AAPs inhibited the growth of harmful bacteria, thereby protecting intestinal barrier function, improving endotoxemia, and decreasing the levels of inflammatory factors such as TNF-α and IL-6. Furthermore, AAPs can inhibit the TLR4/JNK signaling pathway while promoting the activation of AKT and AMPK. Importantly, our study underscored the pivotal role of gut microbiota in the anti-obesity effects of AAPs, as evidenced by fecal microbiota transplantation experiments. In conclusion, our findings elucidated that AAPs improve obesity by regulating gut microbiota and TLR4/JNK signaling pathway, offering novel perspectives for further conclusion the anti-obesity potential of AAPs.

Tolerability and safety of a semi-elemental enteral formula with partially hydrolyzed guar gum (PHGG) in tube-fed children aged 1-4 years: An open-label, single-arm study

BACKGROUND AND AIMS

Partially hydrolyzed guar gum (PHGG) is a water-soluble fiber supporting digestive health with well-established safety and efficacy. This open-label, single-arm, multicenter trial aimed to assess the tolerability and safety of a semi-elemental enteral formula containing PHGG at 12 g/L in tube-fed young children.

METHODS

Children aged 1-4 years with stable conditions requiring tube feeding to provide ≥80% of their nutritional needs received the study formula for seven days. Tolerability, safety, adequacy of energy/protein intake, and weight change were assessed.

RESULTS

Of 24 children (mean age 33.5 months; 10 [41.7%] female), 23 (95.8%) commenced treatment and 18 (75%) completed the study. All children had underlying neuro-developmental disabilities, often in association with gastrointestinal comorbidities requiring treatment for constipation (70.8%) or gastroesophageal reflux (66.7%). The formula was well-tolerated by 19 (82.6%) subjects, while 4 (17.4%; 95% CI: 5%, 39%) subjects withdrew early from the study due to gastrointestinal intolerance. The mean (SD) percentage energy and protein intake across the 7-day period were 103.5% (24.7) and 139.5% [50], respectively. Weight remained stable over the 7-day period (p = 0.43). The study formula was associated with a shift towards softer and more frequent stools. Pre-existing constipation was generally well controlled, and 3/16 (18.7%) subjects ceased laxatives during the study. Adverse events were reported in 12 (52%) subjects and were deemed 'probably related' or 'related' to the formula in 3 (13%) subjects. Gastrointestinal adverse events appeared more common in fiber-naïve patients (p = 0.09).

CONCLUSION

The present study indicates that the study formula was safe and generally well tolerated in young tube-fed children.

CLINICALTRIALS

GOV IDENTIFIER

NCT04516213.

Microbiome analysis of thai traditional fermented soybeans reveals short-chain fatty acid-associated bacterial taxa

Thua Nao is a Thai traditional fermented soybean food and low-cost protein supplement. This study aimed to evaluate the bacterial community in Thua Nao from northern Thailand and assess potentially active short-chain fatty acids (SCFAs)-related bacteria. Sixty-five Thua Nao consisting of 30 wet and 35 dried samples were collected from six provinces: Chiang Rai, Chiang Mai, Mae Hong Son, Lampang, Lamphun, and Phayao. Bacterial diversity was significantly higher in the wet samples than in the dried samples. The dominant phyla were Firmicutes (92.7%), Proteobacteria (6.7%), Actinobacteriota (0.42%), and Bacteroidota (0.26%). The genus Bacillus (67%) was the most represented in all samples. Lactobacillus, Enterococcus, and Globicatella were enriched in the wet samples. Assessment of the SCFA-microbiota relationships revealed that high butyrate and propionate concentrations were associated with an increased Clostridiales abundance, and high acetate concentrations were associated with an increased Weissella abundance. Wet products contained more SCFAs, including acetate (P = 2.8e-08), propionate (P = 0.0044), butyrate (P = 0.0021), and isovalerate (P = 0.017), than the dried products. These results provide insight into SCFA-microbiota associations in Thua Nao, which may enable the development of starter cultures for SCFA-enriched Thua Nao production.

Partially hydrolyzed guar gum is associated with improvement in gut health, sleep, and motivation among healthy subjects

Partially hydrolyzed guar gum dietary fiber is well recognized for a number of health benefits. In the present study, we aim to investigate the effects of partially hydrolyzed guar gum on constipation, intestinal microbiota as well as mental health in healthy subjects. In the randomized, parallel, double-blind, and placebo-controlled study the enrolled healthy men and women volunteers took either 3 g/day (T3) or 5 g/day (T5) of dietary fiber intakes for eight consecutive weeks compared to placebo (T0). The fecal characteristics, fecal microbiota, defecation characteristics, and quality of life (QOL) questionnaire were investigated. The results revealed a significant suppression in fecal potent harmful mucolytic bacteria in the T3 and T5 groups compared to the T0 group. The defecation frequency, excretory feeling, and scores of sleep and motivation questionnaire were also improved in the dietary fiber intake groups, showing a significant difference in the T5 group compared to the T0 group. In summary, the consumption of partially hydrolyzed guar gum dietary fiber is found effective in suppressing the potent harmful mucolytic bacteria that could be associated with the improvement of constipation-related symptoms including mental health in terms of sleep and motivation among the healthy subjects.

Butyrate and obesity: Current research status and future prospect

Over the past few decades, increasing prevalence of obesity caused an enormous medical, social, and economic burden. As the sixth most important risk factor contributing to the overall burden of disease worldwide, obesity not only directly harms the human body, but also leads to many chronic diseases such as diabetes, cardiovascular diseases (CVD), nonalcoholic fatty liver disease (NAFLD), and mental illness. Weight loss is still one of the most effective strategies against obesity and related disorders. Recently, the link between intestinal microflora and metabolic health has been constantly established. Butyrate, a four-carbon short-chain fatty acid, is a major metabolite of the gut microbiota that has many beneficial effects on metabolic health. The anti-obesity activity of butyrate has been demonstrated, but its mechanisms of action have not been fully described. This review summarizes current knowledge of butyrate, including its production, absorption, distribution, metabolism, and the effect and mechanisms involved in weight loss and obesity-related diseases. The aim was to contribute to and advance our understanding of butyrate and its role in obesity. Further exploration of butyrate and its pathway may help to identify new anti-obesity.

Associations of disordered eating with the intestinal microbiota and short-chain fatty acids among young adults with type 1 diabetes

BACKGROUND AND AIMS

Disordered eating (DE) in type 1 diabetes (T1D) includes insulin restriction for weight loss with serious complications. Gut microbiota-derived short chain fatty acids (SCFA) may benefit host metabolism but are reduced in T1D. We evaluated the hypothesis that DE and insulin restriction were associated with reduced SCFA-producing gut microbes, SCFA, and intestinal microbial diversity in adults with T1D.

METHODS AND RESULTS

We collected stool samples at four timepoints in a hypothesis-generating gut microbiome pilot study ancillary to a weight management pilot in young adults with T1D. 16S ribosomal RNA gene sequencing measured the normalized abundance of SCFA-producing intestinal microbes. Gas-chromatography mass-spectrometry measured SCFA (total, acetate, butyrate, and propionate). The Diabetes Eating Problem Survey-Revised (DEPS-R) assessed DE and insulin restriction. Covariate-adjusted and Bonferroni-corrected generalized estimating equations modeled the associations. COVID-19 interrupted data collection, so models were repeated restricted to pre-COVID-19 data. Data were available for 45 participants at 109 visits, which included 42 participants at 65 visits pre-COVID-19. Participants reported restricting insulin "At least sometimes" at 53.3% of visits. Pre-COVID-19, each 5-point DEPS-R increase was associated with a -0.34 (95% CI -0.56, -0.13, p = 0.07) lower normalized abundance of genus Anaerostipes; and the normalized abundance of Lachnospira genus was -0.94 (95% CI -1.5, -0.42), p = 0.02 lower when insulin restriction was reported "At least sometimes" compared to "Rarely or Never".

CONCLUSION

DE and insulin restriction were associated with a reduced abundance of SCFA-producing gut microbes pre-COVID-19. Additional studies are needed to confirm these associations to inform microbiota-based therapies in T1D.

Gut Microbiota and Cardiovascular System: An Intricate Balance of Health and the Diseased State

Gut microbiota encompasses the resident microflora of the gut. Having an intricate relationship with the host, it plays an important role in regulating physiology and in the maintenance of balance between health and disease. Though dietary habits and the environment play a critical role in shaping the gut, an imbalance (referred to as dysbiosis) serves as a driving factor in the occurrence of different diseases, including cardiovascular disease (CVD). With risk factors of hypertension, diabetes, dyslipidemia, etc., CVD accounts for a large number of deaths among men (32%) and women (35%) worldwide. As gut microbiota is reported to have a direct influence on the risk factors associated with CVDs, this opens up new avenues in exploring the possible role of gut microbiota in regulating the gross physiological aspects along the gut-heart axis. The present study elaborates on different aspects of the gut microbiota and possible interaction with the host towards maintaining a balance between health and the occurrence of CVDs. As the gut microbiota makes regulatory checks for these risk factors, it has a possible role in shaping the gut and, as such, in decreasing the chances of the occurrence of CVDs. With special emphasis on the risk factors for CVDs, this paper includes information on the prominent bacterial species (Firmicutes, Bacteriodetes and others) towards an advance in our understanding of the etiology of CVDs and an exploration of the best possible therapeutic modules for implementation in the treatment of different CVDs along the gut-heart axis.

Study on the Effect of Molecular Weight on the Gut Microbiota Fermentation Properties of Blackberry Polysaccharides In Vitro

This study aimed to investigate the effect of different molecular weights on the metabolic characteristics of blackberry polysaccharides (BBP). After degradation, three fractions, namely, BBP-8, BBP-16, and BBP-24, were obtained. During fermentation, all polysaccharide fractions were significantly degraded and utilized by the intestinal microbiota, and the lower-molecular-weight polysaccharides were easier to be fermented with higher gas production and carbohydrate consumption rates. Furthermore, the monosaccharide utilization sequence of all polysaccharides was glucose > galactose > arabinose > galacturonic acid. In addition, the lower-molecular-weight polysaccharides had a faster short-chain fatty acid (SCFA) production rate but did not affect the final SCFA yields. The fermentation of BBP promoted the increase of Bacteroidetes and the decrease of Firmicutes. The proportions of Bacteroidetes in BBP, BBP-8, BBP-16, and BBP-24 were 45.41, 47.50, 48.08, and 50.09%, respectively.

Current evidence on the therapeutic use of fiber in irritable bowel syndrome

INTRODUCTION

Patients with irritable bowel syndrome (IBS) frequently resort to natural products, or request doctors to prescribe them, to relieve their symptoms, due to the poor efficacy and tolerability of several traditional drugs. Products containing fiber are among the most used and their clinical efficacy is discussed here based on the most recent scientific evidence.

AREAS COVERED

A literature search was carried out to identify the most significant publications in order to deal with the topics of the general characteristics of fibers and the scientific evidence underlying their therapeutic use, the properties of ispaghula husk and the mechanisms by which this product carries out its therapeutic actions.

EXPERT OPINION

The most recent clinical guidelines on the management of IBS consider ispaghula husk, a product containing soluble fiber, as a reasonable first line therapy for IBS patients with symptoms. In contrast, products containing insoluble fibers, particularly wheat bran, do not appear to be useful in treating IBS symptoms. The clinical data on the use of prebiotics in IBS are still inconclusive. However, low daily amounts of fructo-oligosaccharides or β-galacto-oligosaccharides (also known as trans-galacto-oligosaccharides) may be effective in improving IBS symptoms; further trials are needed to definitively establish their clinical usefulness.

Chronic systemic low-grade inflammation and modern lifestyle: the dark role of gut microbiota on related diseases with a focus on pandemic COVID-19

Inflammation is a physiological, beneficial and auto-limiting response of the host to alarming stimuli. Conversely, a chronic systemic low-grade inflammation (CSLGI), known as a long-time persisting condition, causes organs and host tissues' damage, representing a major risk for chronic diseases. Currently, a worldwide a high incidence of inflammatory chronic diseases is observed, often linked to the lifestyle-related changes occurred in the last decade's society. The mains lifestyle-related factors are a proinflammatory diet, psychological stress, tobacco smoking, alcohol abuse, physical inactivity, and finally indoor living and working with its related consequences such as indoor pollution, artificial light exposure and low vitamin D production. Recent scientific evidences found that gut microbiota (GM) has a main role in shaping the host's health, particularly as CSLGI mediator. As a matter of facts, based on the last discoveries regarding the remarkable GM activity, in this manuscript we focused on the elements of actual lifestyle that influence the composition and function of intestinal microbial community, in order to elicit the CSLGI and its correlated pathologies. In this scenario, we provide a broad review of the interplay between modern lifestyle, GM and CSLGI with a special focus on the COVID symptoms and emerging long-COVID syndrome.

Dendrobium officinale leaf polysaccharides ameliorated hyperglycemia and promoted gut bacterial associated SCFAs to alleviate type 2 diabetes in adult mice

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Fractions of LDOP show the hypoglycemic effect and can restore histological function of T2D mice.

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There is a difference in the anti-T2D effect between LDOP-A and LDOP-B.

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LDOP-A modulated the gut microbiota composition of T2D mice.

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LDOP-A promotes the formation of SCFAs in T2D mice, especially butyric acid.

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Compared with LDOP-B, LDOP-A shows greater potential to ameliorate T2D.

The present study aimed to explore the possible mechanisms underlying Dendrobium officinale leaf polysaccharides of different molecular weight to alleviate glycolipid metabolic abnormalities, organ dysfunction and gut microbiota dysbiosis of T2D mice. An ultrafiltration membrane was employed to separate two fractions from Dendrobium officinale leaf polysaccharide named LDOP-A and LDOP-B. Here, we present data supporting that oral administration of LDOP-A and LDOP-B ameliorated hyperglycemia, inhibited insulin resistance, reduced lipid concentration, improved β-cell function. LDOP-A with lower molecular weight exhibited improved effect on diabetes than LDOP-B, concurrent with increased levels of colonic short-chain fatty acids (SCFAs) i.e., butyrate, decreased ratio of Firmicutes to Bacteroidetes phyla, and increased abundance of the gut beneficial bacteria i.e., Lactobacillus, Bifidobacterium and Akkermansia. These results suggest that LDOP-A possesses a stronger effect in ameliorating T2D than LDOP-B which may be related to the distinct improved SCFAs levels produced by the change of intestinal flora microstructure.

Partially Hydrolyzed Guar Gum Suppresses the Development of Sarcopenic Obesity

Partially hydrolyzed guar gum (PHGG) is a soluble dietary fiber derived through controlled enzymatic hydrolysis of guar gum, a highly viscous galactomannan derived from the seeds of Cyamopsis tetragonoloba. Here, we examined the therapeutic potential of dietary supplementation with PHGG against sarcopenic obesity using Db/Db mice. Db/Db mice fed a normal diet alone or a fiber-free diet, or supplemented with a diet containing PHGG (5%), were examined. PHGG increased grip strength and the weight of skeletal muscles. PHGG increased the short-chain fatty acids (SCFAs) concentration in feces and sera. Concerning innate immunity, PHGG decreased the ratio of inflammatory cells, while increasing the ratio of anti-inflammatory cells in the small intestine. The present study demonstrated the preventive effect of PHGG on sarcopenic obesity. Changes in nutrient absorption might be involved through the promotion of an anti-inflammatory shift of innate immunity in the intestine accompanied by an increase in SCFA production by PHGG.

Biotechnological Applications of Probiotics: A Multifarious Weapon to Disease and Metabolic Abnormality

Consumption of live microorganisms "Probiotics" for health benefits and well-being is increasing worldwide. Their use as a therapeutic approach to confer health benefits has fascinated humans for centuries; however, its conceptuality gradually evolved with methodological advancement, thereby improving our understanding of probiotics-host interaction. However, the emerging concern regarding safety aspects of live microbial is enhancing the interest in non-viable or microbial cell extracts, as they could reduce the risks of microbial translocation and infection. Due to technical limitations in the production and formulation of traditionally used probiotics, the scientific community has been focusing on discovering new microbes to be used as probiotics. In many scientific studies, probiotics have been shown as potential tools to treat metabolic disorders such as obesity, type-2 diabetes, non-alcoholic fatty liver disease, digestive disorders (e.g., acute and antibiotic-associated diarrhea), and allergic disorders (e.g., eczema) in infants. However, the mechanistic insight of strain-specific probiotic action is still unknown. In the present review, we analyzed the scientific state-of-the-art regarding the mechanisms of probiotic action, its physiological and immuno-modulation on the host, and new direction regarding the development of next-generation probiotics. We discuss the use of recently discovered genetic tools and their applications for engineering the probiotic bacteria for various applications including food, biomedical applications, and other health benefits. Finally, the review addresses the future development of biological techniques in combination with clinical and preclinical studies to explain the molecular mechanism of action, and discover an ideal multifunctional probiotic bacterium.

The gut microbial diversity of colon cancer patients and the clinical significance

The microbial diversity and communities in the excrement of healthy and patients suffered from cancer were identified by 16SrDNA sequencing performed on the Illumina Hi Seq sequencing platform. The microbial difference was also analyzed. The sequencing results showed high quality of the data, and the microbial communities were more various in the excrement of cancer patients. And the abundance of Firmicutes phylum was significantly reduced in cancer group. The phylum of Fermicutes, Bacteroidetes in cancer group are significantly down-regulated and up-regulated compared with normal group. The species of Faecalibacterium prausnitzii, Bateroides vulgatus and Fusicatenibacter saccharivorans are significantly lower in cancer group than that in normal group (P< 0.05). The species of Prevetella copri, M. uniformis, and Escherichia coli are significantly higher in the cancer group than that in normal group. The comparative results indicated that beneficial bacterium significantly decreased in colorectal cancer (CRC) group, and harmful bacterium significantly increased in the colon cancer group, meanwhile the acidity, sugar increased whereas the oxygen content decreased to facilitate the growth of harmful bacterium. The results would provide microbial approaches for the treatment of colon cancer by the intake of beneficial microbial communities.

Characterization of the gut microbiota among Veterans with unique military-related exposures and high prevalence of chronic health conditions: A United States-Veteran Microbiome Project (US-VMP) study

The gut microbiome is impacted by environmental exposures and has been implicated in many physical and mental health conditions, including anxiety disorders, affective disorders, and trauma- and stressor-related disorders such as posttraumatic stress disorder (PTSD). United States (US) military Veterans are a unique population in that their military-related exposures can have consequences for both physical and mental health, but the gut microbiome of this population has been understudied. In this publication, we describe exposures, health conditions, and medication use of Veterans in the US Veteran Microbiome Project (US-VMP) and examine the associations between these characteristics and the gut microbiota. This cohort included 331 US Veterans seeking healthcare with the Veterans Health Administration who were 83% male with an average (±SD) age of 47.6 ​± ​13.4 years. The cohort displayed a high prevalence of PTSD (49.8%) and history of traumatic brain injuries (76.1%), and high current use of prescription medications (74.9%) to treat various acute and chronic conditions. We observed significant associations between the gut microbiota composition and gastroenteritis, peripheral vascular disease (PVD), bipolar disorders, symptoms of severe depression based on the Beck Depression Inventory, stimulant and opioid use disorders, beta-blockers, serotonin and norepinephrine reuptake inhibitor antidepressants, diabetes medications, and proton pump inhibitors. Many of the Veteran characteristics examined were associated with altered relative abundances of specific taxa. We found that PVD and cardiovascular disease were associated with lower microbiota diversity in the gut (i.e., α-diversity), while supplemental vitamin use was associated with higher α-diversity. Our study contributes novel insights as to whether the unique exposures of Veterans in this cohort correlate with gut microbiota characteristics and, in line with previous findings with other population-level studies of the microbiome, confirms associations between numerous health conditions and medications with the gut microbiome.

Defatted flaxseed flour improves weight loss and lipid profile in overweight and obese adults: a randomized controlled trial

SCOPE

Studies have suggested that foods rich in dietary fiber may contribute to body weight loss and lower triacylglycerol (TG) levels. This study aimed to investigate the effect of flaxseed meal (FM) (a by-product of flaxseed after oil processing) supplemented biscuits on body weight, body composition, and blood lipids in overweight and obese participants.

METHOD AND RESULTS

In a double-blind randomized controlled trial, 53 overweight and obese adults (18-36 years of age) were recruited and randomized to consume control biscuits or biscuits supplemented with FM for their breakfast for 60 days (approximately 100 g per day). Significant group × time interaction (P = 0.011) was observed for body weight, and the body weight of the FM group was significantly lower than that of the control group (P = 0.049). We also found significant group × time interactions for body mass index (BMI) (P = 0.008), TG (P = 0.041) and interleukin-6 (IL-6) (P = 0.016). In addition, after 60 days of intervention, the body weight, BMI and TG levels of the FM group significantly decreased compared to those of the control group. On day 60, the serum concentration of IL-6 in the FM group was significantly lower than that in the control group.

CONCLUSIONS

FM supplemented biscuits have a beneficial effect on body weight, BMI and TG of overweight and obese subjects (ClinicalTrials.gov registration number: ChiCTR1900022833).

Quality characteristics of yogurts fermented with short-chain fatty acid-producing probiotics and their effects on mucin production and probiotic adhesion onto human colon epithelial cells

Probiotics can ferment nondigestible carbohydrates and produce short-chain fatty acids (SCFA; acetate, propionate, and butyrate) in the human colon. In this study, the levels of SCFA were determined in the following yogurts fermented with different combinations of probiotics: (1) cocultures of Streptococcus thermophilus and Lactobacillus bulgaricus (control, C); (2) S. thermophilus, L. bulgaricus, and Bifidobacterium bifidum (C-Bb); (3) S. thermophilus, L. bulgaricus, and Lactobacillus acidophilus (C-La); and (4) S. thermophilus, L. bulgaricus, and Lactobacillus gasseri (C-Lg). Results showed that the acetate levels were significantly higher in C-Bb, C-La, and C-Lg yogurts than in C yogurt. Fermentation and physicochemical characteristics of all yogurts were identical. Treatment of mucus-secreting colon epithelial cells (HT29-MTX) with C-Bb, C-La, and C-Lg yogurt supernatants resulted in an increase in the expression of MUC2 and CDX2 and the production of mucin proteins. The adhesion of probiotics onto HT29-MTX cells increased following treatment with C-Bb, C-La, and C-Lg yogurt supernatants. Our data suggest that a yogurt diet rich in acetate improves the protective function of the intestinal epithelium.

Effect of Enteral Nutrition on In-hospital Infection and Hospital Expense in Stroke Patients: A Retrospective Assessment

Infection is a common complication of stroke and is associated with unfavorable outcomes. Although nutritional intervention reduces the risk of postoperative infection, the impact of specific nutritional products remains unclear. From a hospital management perspective, we aimed to determine whether the provision of specific types of enteral nutrition in acute stroke patients affects infection control and hospital costs. In all, 45 acute hemorrhagic stroke patients receiving enteral nutrition in a single center (April 2017-March 2019) were retrospectively assessed. Patients were divided into two groups according to nutritional interventions: the 1.0-group with general nutrition (1.0 kcal/mL) (24 patients) and the 1.5+α-group with an initial high-protein, whey peptide-digested liquid diet (1.5 kcal/mL), followed by a highly fermentable fiber-containing liquid diet (1.5 kcal/mL initiated after 4 days) (21 patients). Changes in body mass index (BMI), duration of antibiotic use, incidence of postoperative infection, and medical cost were evaluated. Baseline patient characteristics were similar between groups. The mean BMI change was lower in the 1.5+α-group than in the 1.0-group, and the mean duration of antibiotic use throughout hospitalization was 12.8 and 18.3 days, respectively. Antibiotic use in the 1.5+α-group was lesser than that in Japanese patients from other hospitals. The incidence of postoperative infections was lower in the 1.5+α-group. Injection costs for the 1.5+α group (615 USD/patient) were lower than those for the 1.0-group. Enteral nutrition provided to acute stroke patients reduced the risk of hospital infection and medical costs.

Dietary fibre in gastrointestinal health and disease

Epidemiological studies have consistently demonstrated the benefits of dietary fibre on gastrointestinal health through consumption of unrefined whole foods, such as wholegrains, legumes, vegetables and fruits. Mechanistic studies and clinical trials on isolated and extracted fibres have demonstrated promising regulatory effects on the gut (for example, digestion and absorption, transit time, stool formation) and microbial effects (changes in gut microbiota composition and fermentation metabolites) that have important implications for gastrointestinal disorders. In this Review, we detail the major physicochemical properties and functional characteristics of dietary fibres, the importance of dietary fibres and current evidence for their use in the management of gastrointestinal disorders. It is now well-established that the physicochemical properties of different dietary fibres (such as solubility, viscosity and fermentability) vary greatly depending on their origin and processing and are important determinants of their functional characteristics and clinical utility. Although progress in understanding these relationships has uncovered potential therapeutic opportunities for dietary fibres, many clinical questions remain unanswered such as clarity on the optimal dose, type and source of fibre required in both the management of clinical symptoms and the prevention of gastrointestinal disorders. The use of novel fibres and/or the co-administration of fibres is an additional therapeutic approach yet to be extensively investigated.

Diet, Perceived Intestinal Well-Being and Compositions of Fecal Microbiota and Short Chain Fatty Acids in Oat-Using Subjects with Celiac Disease or Gluten Sensitivity

A gluten-free diet may result in high fat and low fiber intake and thus lead to unbalanced microbiota. This study characterized fecal microbiota profiles by 16S MiSeq sequencing among oat-using healthy adult subjects (n = 14) or adult subjects with celiac disease (CeD) (n = 19) or non-celiac gluten sensitivity (NCGS) (n = 10). Selected microbial metabolites, self-reported 4d food diaries and perceived gut symptoms were compared. Subjects with NCGS experienced the highest amount of gut symptoms and received more energy from fat and less from carbohydrates than healthy and CeD subjects. Oat consumption resulted in reaching the lower limit of the recommended fiber intake. Frequent consumption of gluten-free pure oats did not result in microbiota dysbiosis in subjects with CeD or NCGS. Thus, the high number of gut symptoms in NCGS subjects was not linked to the microbiota. The proportion of fecal acetate was higher in healthy when compared to NCGS subjects, which may be linked to a higher abundance of Bifidobacterium in the control group compared to NCGS and CeD subjects. Propionate, butyrate and ammonia production and β-glucuronidase activity were comparable among the study groups. The results suggest that pure oats have great potential as the basis of a gluten-free diet and warrant further studies in minor microbiota disorders.

High-Fat Diet Induced Alteration of Mice Microbiota and the Functional Ability to Utilize Fructooligosaccharide for Ethanol Production

High-fat diet (HFD) leads to enhancement in various parameters of mice like weight, fasting glucose levels, adipose tissue, and also the liver weight in male C57 BL/6 J mice. Additionally, high-fat diet causes severe liver damage with significant increase in the level of aspartate amino transferase (AST) and alanine transaminase (ALT). The variations in microbiota induced by different diet were analyzed by Illumina MiSeq platform with sequencing of 16S ribosomal RNA (rRNA) gene, and QIIME pipeline was used. The population of Proteobacteria was found to be higher in HFD cecum sample as compared to other treatments. Microbiota analysis suggests that phylum Proteobacteria and Firmicutes were found to be higher in high-fat diet groups as compared to mice fed with normal diet (ND). At the genus level, Bacteroides showed higher population in HFD diet. Bacterial strains belonging to Enterobacteriaceae like Escherichia, Klebsiella, and Shigella were also dominant in HFD treatments. Furthermore, we explored the effects of ethanol production in vitro with supplementation of dietary fibers following inoculation of ND and HFD microbiotas. HFD microbiota of cecum and feces showed high level (P < 0.05) of ethanol production with 2% fructooligosaccharide (FOS) as compared to 2% galactomannan. Microbial fermentation also generated short-chain fatty acids (SCFAs), such as acetate, propionate, and butyrate. High levels (P < 0.05) of propionate were found after fermentation of FOS with HFD cecum and feces microbiota. The present study highlights the HFD-induced population of phylum Proteobacteria and genus Bacteroides for ethanol production using FOS as a dietary supplement, and these findings may imply on the harmful effect of HFD even at the microbiota level.

Short-chain fatty acid, acylation and cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide. Metabolic dysfunction is a fundamental core mechanism underlying CVDs. Previous studies generally focused on the roles of long-chain fatty acids (LCFAs) in CVDs. However, a growing body of study has implied that short-chain fatty acids (SCFAs: namely propionate, malonate, butyrate, 2-hydroxyisobutyrate (2-HIBA), β-hydroxybutyrate, crotonate, succinate, and glutarate) and their cognate acylations (propionylation, malonylation, butyrylation, 2-hydroxyisobutyrylation, β-hydroxybutyrylation, crotonylation, succinylation, and glutarylation) participate in CVDs. Here, we attempt to provide an overview landscape of the metabolic pattern of SCFAs in CVDs. Especially, we would focus on the SCFAs and newly identified acylations and their roles in CVDs, including atherosclerosis, hypertension, and heart failure.

Digestive Property and Bioactivity of Blackberry Polysaccharides with Different Molecular Weights

In the present study, the digestion and fermentation of blackberry polysaccharides (BBPs) with different molecular weights (M_w) were investigated. The results showed that the M_w decrease rates of BBP, BBP-8, BBP-16, and BBP-24 were 77.48, 69.61, 56.87, and 52.89%, respectively. The antioxidant and α-glucosidase inhibitory activities of BBPs were decreased under gastrointestinal condition, which might be due to the variation of M_w during digestion. The bile acid-binding ability of BBPs showed an M_w-dependent manner for higher M_w polysaccharides with higher viscosity. Through fermentation, the BBPs affected the ecosystem of the intestinal tract by promoting the production of short-chain fatty acids, lowering the pH of colon, and decreasing the ratio of Firmicutes to Bacteroidetes. All BBPs showed almost a similar modulation effect on the gut bacteria, but the lower M_w polysaccharide was more easily utilized by bacteria.

COPD and the gut-lung axis: the therapeutic potential of fibre

Current management strategies for chronic obstructive pulmonary disease (COPD) incorporate a step-wise, multidisciplinary approach to effectively manage patient symptoms and prevent disease progression. However, there has been limited advancement in therapies to address the underlying cause of COPD pathogenesis. Recent research has established the link between the lungs and the gut-the gut-lung axis -and the gut microbiome is a major component. The gut microbiome is likely perturbed in COPD, contributing to chronic inflammation. Diet is a readily modifiable factor and the diet of COPD patients is often deficient in nutrients such as fibre. The metabolism of dietary fibre by gut microbiomes produces anti-inflammatory short chain fatty acid (SCFAs), which could protect against inflammation in the lungs. By addressing the 'fibre gap' in the diet of COPD patients, this targeted dietary intervention may reduce inflammation, both systemically and in the airways, and value-add to the paradigm shift in respiratory medicine, from reactive to personalised and participatory medicine.

Effect of Repeated Consumption of Partially Hydrolyzed Guar Gum on Fecal Characteristics and Gut Microbiota: A Randomized, Double-Blind, Placebo-Controlled, and Parallel-Group Clinical Trial

Partially hydrolyzed guar gum (PHGG) is a water-soluble dietary fiber and is used in solid and liquid food to regulate gut function. The aim of this study was to investigate effects of PHGG on bowel movements (stool form and frequency), plasma bile acids, quality of life, and gut microbiota of healthy volunteers with a tendency toward diarrhea, i.e., irritable bowel syndrome diarrhea (IBS-D)-like symptoms. A randomized, double-blind, placebo-controlled, and parallel trial was performed on 44 healthy volunteers (22 males, 22 females, 41.9 ± 6.3 years old (average ± SD)) with minimum 7 bowel movements every week, wherein above 50% of their stool was between the Bristol stool scale (BSS) value of 5 and 6. Intake of the PHGG for 3 months significantly improved stool form, evaluated using BSS, and had no effects on stool frequency. BSS was significantly normalized in the group consuming the PHGG compared with the placebo. Comprehensive fecal microbiome analysis by the 16S rRNA-sequence method detected significant changes in the ratio of some bacteria, such as an increase of Bifidobacterium (p < 0.05) in the PHGG group. Our results suggest that intake of PHGG improves human stool form via regulating intestinal microbiota.

Sex, gut microbiome, and cardiovascular disease risk

Key differences exist between men and women in the determinants and manifestations of cardiovascular and cardiometabolic diseases. Recently, gut microbiome-host relations have been implicated in cardiovascular disease and associated metabolic conditions; therefore, gut microbiota may be key mediators or modulators driving the observed sexual dimorphism in disease onset and progression. While current evidence regarding pure physiological sex differences in gut microbiome composition is modest, robust research suggests that gut microbiome-dependent metabolites may interact with important biological pathways under sex hormone control, including toll-like receptor and flavin monooxygenase signaling. Here, we review key sex differences in gut microbiome interactions with four primary determinants of cardiovascular disease, impaired glucose regulation, dyslipidemia, hypertension, and obesity. Through this process, we propose important sex differences in downstream metabolic pathways that may be at the interface of the gut microbiome and cardiovascular disease.

Gut microbial metabolites in obesity, NAFLD and T2DM

Evidence is accumulating that the gut microbiome is involved in the aetiology of obesity and obesity-related complications such as nonalcoholic fatty liver disease (NAFLD), insulin resistance and type 2 diabetes mellitus (T2DM). The gut microbiota is able to ferment indigestible carbohydrates (for example, dietary fibre), thereby yielding important metabolites such as short-chain fatty acids and succinate. Numerous animal studies and a handful of human studies suggest a beneficial role of these metabolites in the prevention and treatment of obesity and its comorbidities. Interestingly, the more distal colonic microbiota primarily ferments peptides and proteins, as availability of fermentable fibre, the major energy source for the microbiota, is limited here. This proteolytic fermentation yields mainly harmful products such as ammonia, phenols and branched-chain fatty acids, which might be detrimental for host gut and metabolic health. Therefore, a switch from proteolytic to saccharolytic fermentation could be of major interest for the prevention and/or treatment of metabolic diseases. This Review focuses on the role of products derived from microbial carbohydrate and protein fermentation in relation to obesity and obesity-associated insulin resistance, T2DM and NAFLD, and discusses the mechanisms involved.

Nondigestible carbohydrates, butyrate, and butyrate-producing bacteria

Nondigestible carbohydrates (NDCs) are fermentation substrates in the colon after escaping digestion in the upper gastrointestinal tract. Among NDCs, resistant starch is not hydrolyzed by pancreatic amylases but can be degraded by enzymes produced by large intestinal bacteria, including clostridia, bacteroides, and bifidobacteria. Nonstarch polysaccharides, such as pectin, guar gum, alginate, arabinoxylan, and inulin fructans, and nondigestible oligosaccharides and their derivatives, can also be fermented by beneficial bacteria in the large intestine. Butyrate is one of the most important metabolites produced through gastrointestinal microbial fermentation and functions as a major energy source for colonocytes by directly affecting the growth and differentiation of colonocytes. Moreover, butyrate has various physiological effects, including enhancement of intestinal barrier function and mucosal immunity. In this review, several representative NDCs are introduced, and their chemical components, structures, and physiological functions, including promotion of the proliferation of butyrate-producing bacteria and enhancement of butyrate production, are discussed. We also describe the strategies for achieving directional accumulation of colonic butyrate based on endogenous generation mechanisms.

Galactomannan from Trigonella foenum-graecum L. seed: Prebiotic application and its fermentation by the probiotic Bacillus coagulans strain MTCC 5856

Health benefits of dietary fibers are currently being widely recognized. However, the assessment of dietary fiber as a prebiotic is essential and also important for the development of an improved synbiotic commercial preparation. Thus, the aim of this study was to evaluate the potential of galactomannan extracted from fenugreek seeds as a prebiotic fiber and also its fermentation by the probiotic strain Bacillus coagulans MTCC 5856. Nondigestibility by the gastric acid and pancreatic enzyme hydrolysis of galactomannan were determined using an in vitro model mimicking the in vivo conditions. Further, anaerobic fermentation and utilization of galactomannan by the B. coagulans MTCC 5856 was investigated followed by selective inhibition of Escherichia coli ATCC 25922. The galactomannan from fenugreek seeds was found to be nondigestible to gastric acid and also to pancreatic enzymatic hydrolysis. The galactomannan was fermented and utilized (71.4%) by the B. coagulans MTCC 5856, and also significant amount of short-chain fatty acids production was also observed. Furthermore, B. coagulans MTCC 5856 inhibited the E. coli ATCC 25922 growth when cocultured with galactomannan suggesting competitive fermentation of probiotic bacteria. Galactomannan exhibited prebiotic activity and also showed suitability with probiotic B. coagulans MTCC 5856 in a synbiotic combination. This study provides the first scientific evidence of galactomannan from fenugreek seeds as a prebiotic that may play an important role in modulating gut flora by acting as substrate to beneficial microbes.

Gut microbiota and chronic kidney disease: implications for novel mechanistic insights and therapeutic strategies

The complicated communities of microbiota colonizing the human gastrointestinal tract exert a strong function in health maintenance and disease prevention. Indeed, accumulating evidence has indicated that the intestinal microbiota plays a key role in the pathogenesis and development of chronic kidney disease (CKD). Modulation of the gut microbiome composition in CKD may contribute to the accumulation of gut-derived uremic toxins, high circulating level of lipopolysaccharides and immune deregulation, all of which play a critical role in the pathogenesis of CKD and CKD-associated complications. In this review, we discuss the recent findings on the potential impact of gut microbiota in CKD and the underlying mechanisms by which microbiota can influence kidney diseases and vice versa. Additionally, the potential efficacy of pre-, pro- and synbiotics in the restoration of healthy gut microbia is described in detail to provide future directions for research.