In vitro analysis of partially hydrolyzed guar gum fermentation on identified gut microbiota

The effectiveness and safety of natural food and food-derived extract supplements for treating functional gastrointestinal disorders-current perspectives

Functional gastrointestinal disorders (FGIDs) were highly prevalent and involve gastrointestinal discomfort characterized by non-organic abnormalities in the morphology and physiology of the gastrointestinal tract. According to the Rome IV criteria, irritable bowel syndrome and functional dyspepsia are the most common FGIDs. Complementary and alternative medicines are employed by increasing numbers of individuals around the world, and they include herbal and dietary supplements, acupuncture, and hypnosis. Of these, herbal and dietary supplements seem to have the greatest potential for relieving FGIDs, through multiple modes of action. However, despite the extensive application of natural extracts in alternative treatments for FGIDs, the safety and effectiveness of food and orally ingested food-derived extracts remain uncertain. Many randomized controlled trials have provided compelling evidence supporting their potential, as detailed in this review. The consumption of certain foods (eg, kiwifruit, mentha, ginger, etc) and food ingredients may contribute to the alleviation of symptoms associated with FGID,. However, it is crucial to emphasize that the short-term consumption of these components may not yield satisfactory efficacy. Physicians are advised to share both the benefits and potential risks of these alternative therapies with patients. Furthermore, larger randomized clinical trials with appropriate comparators are imperative.

Metabolic response of intestinal microbiota to guar gum consumption

Background

Guar gum is used extensively as a thickening agent in food, but it remains uncertain whether and to what extent it is fermented by colonic microbiota and whether it has microbiota modulatory properties.

Aim

To determine the metabolic response of intestinal microbiota to guar gum consumption, specifically, the extent of initial fermentation and subsequent adaptation.

Methods

Single-center, single arm, open label, proof-of-concept study testing the effect of guar gum on microbiota metabolism and adaptation. Healthy male subjects (n = 12) were administered gum guar (8 g/day) for 18 days. Outcomes were measured before, at initial and late administration: (a) anal gas evacuations (number/day); (b) digestive sensations (daily scales); and (c) fecal gut microbiota taxonomy and metabolic functions by shotgun sequencing.

Results

At initial consumption, guar gum induced a transient increase in anal gas evacuations and digestive sensations; gas evacuation completely reverted upon continuous administration, whereas sensations reverted only in part. Guar gum induced moderate changes in human microbiota composition at both taxonomic and functional levels. Positive associations between effects on microbiota (proliferation of Agathobaculum butyriciproducens and Lachnospira pectinoschiza) and hedonic sensations were detected.

Conclusion

Guar gum is metabolized by intestinal microbiota, and, upon continuous consumption, induces a selective adaptation of microbial taxonomy and function. These data highlight the potential interest of guar gum for novel prebiotic ingredient formulation.

Effects of partially hydrolyzed guar gums of different molecular weights on a human intestinal in vitro fermentation model

Partially hydrolyzed guar gums (PHGGs) are prebiotic soluble dietary fibers. High molecular-weight PHGGs have rapid fermentation and high short-chain fatty acid (SCFA) productivity rates, compared to low molecular-weight PHGGs. Therefore, low molecular-weight PHGGs may have less pronounced prebiotic effects than high molecular-weight PHGGs. However, the effects of PHGGs of different molecular weights on the human intestinal microbiota, as well as their fermentation ability and prebiotic effects, have not been investigated. The aim of this study was to evaluate the effects of two PHGGs of different molecular weights, Sunfiber-R (SF-R; 20 kDa) and Sunfiber-V (SF-V; 5 kDa), on human colonic microbiota and SCFA production. A human intestinal in vitro fermentation model was operated by fecal samples with and without the PHGGs. The addition of 0.2% SF-R or SF-V increased the relative abundance of Bacteroides spp., especially that of Bacteroides uniformis. This increase corresponded to a significant (p = 0.030) and non-significant (p = 0.073) increase in propionate production in response to SF-R and SF-V addition, respectively. Both fibers increased the relative abundance of Faecalibacterium and stimulated an increase in the abundance of unclassified Lachnospiraceae and Bifidobacterium. In conclusion, the low molecular-weight PHGG exerted prebiotic effects on human colonic microbiota to increase SCFA production and bacteria that are beneficial to human health in a manner similar to that of the high molecular-weight forms of PHGG.

Dietary Supplement of Amomum villosum Lour. Polysaccharide Attenuates Ulcerative Colitis in BALB/c Mice

Amomum villosum Lour. (A. villosum), a comestible medicinal plant, has been traditionally used in China to treat diarrhea, stomach fullness, and abdominal distension. Polysaccharide, the main chemical component of A. villosum, has been shown to possess potential antioxidant and glycosidase inhibitory activities; however, whether it has anticolitis activity is unknown. The aim of this research was to evaluate the anticolitis effects of A. villosum polysaccharide (AVLP) in BALB/c mice. The results showed that AVLP administration significantly reversed body weight loss, colon shortening and colon weight gain and decreased the levels of proinflammatory cytokines and chemokines in colitis mice (p < 0.05). AVLP administration also maintained intestinal barrier function by the upregulation of ZO-1 protein expression (p < 0.05). In addition, high-throughput sequencing analysis showed that AVLP possessed a great regulatory effect on the growth of Adlercreutzia, Clostridium, Streptococcus, Parabacteroides, Helicobacter, Odoribacter, and Alistipes (p < 0.05, LDA score > 2). The correlation analysis revealed that the protective effects against colitis of AVLP were highly correlated with intestinal bacterium regulation. These results suggest that AVLP intake could serve as a prospective nutritional strategy for inflammatory bowel diseases.

Intervention and potential mechanism of non-starch polysaccharides from natural resources on ulcerative colitis: A review

Ulcerative colitis (UC) is a chronic inflammatory bowel disease of unknown etiology that affects the colon and rectum. It has evolved into a global burden due to the high incidence in developed countries and the highly-increased incidence in developing countries. Non-starch polysaccharides (NSPs) from natural resources, as a type of functional carbohydrates, have a significant therapeutic effect on UC because of their good anti-inflammatory and immunomodulatory activities. Based on the etiology and pathogenesis of UC, this review summarizes the intervention effects and mechanisms of NSPs in the prevention and treatment of UC. The results showed that NSPs can improve UC by protecting the intestinal mucosal barrier, regulating the immune response of the intestinal mucosa, and remodeling the intestinal flora and metabolites. These contents provide theoretical basis for the application of polysaccharides in the prevention and treatment of UC.

Partially Hydrolyzed Guar Gum Modulates Gut Microbiota, Regulates the Levels of Neurotransmitters, and Prevents CUMS-Induced Depressive-Like Behavior in Mice

SCOPE

Depression is the leading cause of disability around the world; however, most antidepressants have drug tolerance and serious side effects. In this study, it is explored whether partially hydrolyzed guar gum (PHGG) is a safe food that exhibits protection in a mouse model of depression.

METHODS AND RESULTS

PHGG is orally administered to mice with depression induced by chronic unpredictable mild stress (CUMS) in two animal experiments (prevention trial and intervention trial) to characterize the potentially protective effect of PHGG. The results in the prevention trial show that PHGG significantly inhibits the loss of body weight, and prevents CUMS-induced depressive-like behavior in mice. The beneficial effects may be associated with PHGG modulating the gut microbiota structure and then increasing the levels of short-chain fatty acids in mice feces and the levels of 5-hydroxytryptamine and dopamine in serum, striatum, and hippocampus. Besides, PHGG in the intervention trial is less effective than that in the prevention trial, but it may have a synergistic effect on improving depression with fluoxetine.

CONCLUSIONS

This study suggests that moderate daily intake of PHGG can contribute to relieving depressive-like behavior.

Role of a berberine-based nutritional supplement in reducing diarrhea in subjects with functional gastrointestinal disorders

BACKGROUND

Berberine, an alkaloid obtained by extraction from Berberis spp., is a botanical that is widely used in the nutraceutical sector to control cholesterol and blood glucose levels. It is also a molecule that is effective in limiting diarrhea due to its multi-factorial properties, including its antimicrobial, gut eubiotic and antisecretive actions, and its ability to slow gut motility. In our routine clinical practice, we have suggested the use of a berberine-based nutraceutical, formulated with melatonin and depolymerized guar gum, to patients affected by functional diarrhea (FD) or by diarrhea-type irritable bowel syndrome (IBS-D).

METHODS

We have therefore retrospectively analyzed the clinical effect of such a nutritional supplement in these two sub-groups of patients.

RESULTS

Despite the highly pragmatic scheme of our study, our findings strongly confirm the antidiarrheal properties of berberine and recommend its use in some gut functional diseases characterized by frequent evacuation of mushy and/or watery stools. In fact, even after 30 days of treatment, the berberine-based nutritional supplement significantly reduces diarrheal events by 50-70%. After 90 days, this reduction improves to between 70 and 80%, with a reduction of more than 60% in the number of evacuations per week and with more than 50% of treated subjects demonstrating normalized, according to self-reported Bristol Stool Scale categorization, stool consistency. The product is well tolerated and adherence to the proposed therapy is good. Common side effects of the product are flatulence and meteorism, likely due to the "acarbose-like" berberine effects on gut α-glucosidase.

CONCLUSIONS

Patients, especially those preferring "natural" therapy, can be successfully treated, when affected by a gut functional disease characterized by diarrhea, by berberine-based products.

Hydratability and improved fermentability in vitro of guar gum by combination of xanthan gum

Dietary fibers with high water-binding capacity (WBC), swelling capacity (SC) and fermentability regulate food intake and intestinal microbiota. However, dietary fibers with such properties are generally rare or expensive. We evaluated SC, WBC, fermentability and bacterial shifts during in vitro fermentations of guar gum (GG), xanthan gum (XG) and the combined gum (CG) of XG and GG. SC and WBC were enhanced by the combination of GG and XG. Fermentation of CG showed similar Short chain fatty acids production and lower molecular weight compared with GG. Analyzing of fermentation kinetics by logistic-exponential model, initial fractional rate of degradation of CG were remarkable higher than GG. Microbiota analysis revealed that GG enriched Fusobacterium, Bacteriodes and Prevotella_9, and CG lead to promotion of Sphaerochaeta, Prevotella_9, Bacteroides and Christensenellaceae_R-7_group. These data suggest that combination of XG to GG changed hydration and fermentation characteristics of GG, and CG resulted in promotion of beneficial microbiota.

Polysaccharides from natural resources exhibit great potential in the treatment of ulcerative colitis: A review

The incidence of ulcerative colitis (UC) is high. Despite the availability of various therapeutic agents for the treatment of UC, the routine treatment has limitations and serious side effects. Therefore, a new drug that safely and effectively treats UC is urgently needed. Polysaccharides from natural resources have recently become a hot topic of study for their therapeutic effects on UC. These effects are associated with the regulation of inflammatory cytokines, intestinal flora, and immune system and protection of the intestinal mucosa. This review focuses on the recent advances of polysaccharides from natural resources in the treatment of UC. The mechanisms and practicability of polysaccharides, including pectin, guar gum, rhamnogalacturonan, chitosan, fructan, psyllium, glycosaminoglycan, algal polysaccharides, polysaccharides from fungi and traditional Chinese medicine, and polysaccharide derivatives, are discussed in detail. The good efficacy and safety of polysaccharides make them promising drugs for treating UC.

High-sugar diet intake, physical activity, and gut microbiota crosstalk: Implications for obesity in rats

This study aims to evaluate the effect of long-term high-sugar diet (HSD) intake and regular physical activity on gut microbiota as well as its health impact. Weaned male Wistar rats were fed with standard chow diet (SSD) or HSD ad libitum and subjected or not to regular swimming training with a workload (2% of body weight) for 15 weeks. Feces samples were used on microbiome analysis using 16S rRNA amplicon sequencing. HSD increased body mass, adipose cushions, and the serum levels of triglycerides and VLDL, also changed the bacteria taxons associated with metabolic disorders (increase taxons belonging to Proteobacteria phylum and decrease Pediococcus genus); the swim training reverted these changes. SSD intake increased the abundance of bacteria associated with metabolization of dietary fiber. Training in association with SSD consumption beneficially modulated the microbiota, increasing the Bacteroidetes, Bacteroidaceae, Porphyromonadaceae, Parabacteroides, and Lactobacillaceae, and decreasing the Firmicute/Bacteroidetes ratio; training was not able to maintain this profile in animals SHD-fed. Physical training modulates the gut microbiota reversing the obesogenic response caused by SHD. However, training itself is not efficient for up-regulating the probiotic bacteria in comparison to its association with a balanced diet.

The effect of preoperative synbiotic treatment to prevent surgical-site infection in hepatic resection

We aimed to clarify the influence of preoperative synbiotic therapy on surgical-site infections (SSIs) after hepatic resection. Between January 2011 and December 2017, 284 patients who underwent hepatic resection without biliary tract reconstruction and resection of other organs were included. We prospectively administered Clostridium butyricum and partially hydrolyzed guar gum before hepatic resection between April 2016 and December 2017 (synbiotic group). One-hundred-fifteen patients of the synbiotic group and 169 patients (conventional group) treated between January 2011 and the end of March 2016 were compared using propensity score matching. The frequency of laparoscopic resection was significantly larger in the synbiotic group (conventional group; 28% vs synbiotic group; 55%, p<0.001) and the amount of intraoperative bleeding was significantly smaller in the synbiotic group (median; conventional group, 700 ml vs synbiotic group, 200 ml; p<0.001). The postoperative SSI was significantly lower in the synbiotic group of six patients (5.2%) than in the conventional group of 30 patients (17.8%) (p = 0.002). Sixty patients in each group remained after propensity score matching. There was no significant difference in the incidence of SSI between the groups (conventional group, 15% vs synbiotic group, 6.7%; p = 0.239). In conclusion, preoperative synbiotic treatment did not reduce SSIs after hepatic resection.

Hepatoprotective Potential of Partially Hydrolyzed Guar Gum against Acute Alcohol-Induced Liver Injury in Vitro and Vivo

Natural polysaccharides, particularly galactomannans, are potential candidates for treatment of alcoholic liver diseases (ALD). However, applications are restricted due to the physicochemical properties associated with the high molecular weight. In this work, guar gum galactomannans were partially hydrolyzed by β-mannanase, and the molecular mechanisms of hepatoprotective effects were elucidated both in vitro and in vivo. Release of lactate dehydrogenase and cytochrome C were attenuated by partially hydrolyzed guar gum (PHGG) in HepG2 cells, due to protected cell and mitochondrial membrane integrity. PHGG co-administration decreased serum amino transaminases and cholinesterase levels of acute alcohol intoxicated mice, while hepatic pathologic morphology was depleted. Activity of superoxide dismutase, catalase, and glutathione peroxidase was recovered to 198.2, 34.5, 236.0 U/mg protein, respectively, while malondialdehyde level was decreased by 76.3% (PHGG, 1000 mg/kg∙day). Co-administration of PHGG induced a 4.4-fold increment of p-AMPK expression, and lipid metabolism was mediated. PHGG alleviated toll-like-receptor-4-mediated inflammation via the signaling cascade of MyD88 and IκBα, decreasing cytokine production. Moreover, mediated expression of Bcl-2 and Bax was responsible for inhibited acute alcohol-induced apoptosis with suppressed cleavage of caspase 3 and PARP. Findings gained suggest that PHGG can be used as functional food supplement for the treatment of acute alcohol-induced liver injury.

In vitro fermentation of arabinoxylan from oat (Avena sativa L.) by Pekin duck intestinal microbiota

Arabinoxylan (AX) is abundant in cereal grains used as feed for ducks. However, the duck intestinal microbes responsible for the degradation of AX are not fully understood. In this study, oat AX was degraded and utilized by different duck intestinal microbiota in vitro. Changes in short-chain fatty acids (SCFAs), branch-chain fatty acids, and the pH resulted from a 72-h AX fermentation in intestinal samples were measured. The addition of AX increased the concentration of isobutyric acid and decreased the concentrations of SCFAs. The pH values decreased significantly in the intestinal samples. Gut microbiota were assessed using high-throughput sequencing of the 16S ribosomal RNA gene, and the results indicated that AX stimulated the growth of Megamonas and Bifidobacterium species, with Megamonas exhibiting the greatest stimulation. Overall, the results suggest that oat AX is utilized by specific bacteria in duck intestines, providing the theoretical basis for the impacts of AX on animal health.

An integrated metabolomics and 16S rRNA gene sequencing approach exploring the molecular pathways and potential targets behind the effects of Radix Scrophulariae

To assess the impact of the caecal microbiota on faecal metabolic phenotypes in the presence of Radix Scrophulariae (Chinese name: Xuanshen), an integrated approach involving 16S rRNA gene sequencing combined with ultrahigh-performance liquid chromatography/time-of-flight mass spectrometry (UHPLC/TOF-MS)-based faecal metabolomics was applied to Radix Scrophulariae-treated rats. Interestingly, Radix Scrophulariae led to significant gut microbiota changes at the phylum and genus levels in treated rats compared to control rats. Additionally, distinct changes in faecal metabolites, including linoleic acid (LA), guanosine, inosine, hypoxanthine, xanthine, 4-hydroxycinnamic acid, cholic acid, N-acetyl-d-glucosamine, l-urobilinogen and uridine, were observed in Radix Scrophulariae-treated rats. Of these, seven metabolites were up-regulated, and the remaining three metabolites were down-regulated. Moreover, there were substantial associations between altered levels of gut microbiota genera and discrepant levels of faecal metabolites, particularly for compounds involved in LA and purine metabolism. These results demonstrated that the gut microbiota is altered in association with faecal metabolism following treatment with Radix Scrophulariae. Our findings suggest that further application of this 16S rRNA gene sequencing and UHPLC/TOF-MS-based metabolomics approach will facilitate the assessment of the pharmacological action of Radix Scrophulariae and thus expand the scope of this herb.

An integrated approach to assess impact of caecal microbiota on faecal metabolic phenotypes in the presence of Radix Scrophulariae involving 16S rRNA gene sequencing combined with UHPLC/TOF-MS-based faecal metabolomics was applied to Radix Scrophulariae-treated rats.

Impact of Agaricus bisporus Mushroom Consumption on Gut Health Markers in Healthy Adults

Eating Agaricus bisporus mushrooms may impact gut health, because they contain known prebiotics. This study assessed mushroom consumption compared to meat on gastrointestinal tolerance, short chain fatty acid (SCFA) production, laxation, and fecal microbiota. A randomized open-label crossover study was conducted in healthy adults (n = 32) consuming protein-matched amounts of mushrooms or meat twice daily for ten days. Breath hydrogen measures were taken on day one, and gastrointestinal tolerance was evaluated throughout treatments. Fecal sample collection was completed days 6⁻10, and samples were assessed for bacterial composition, SCFA concentrations, weight, pH, and consistency. There were no differences in breath hydrogen, stool frequency, consistency, fecal pH, or SCFA concentrations between the two diets. The mushroom diet led to greater overall gastrointestinal symptoms than the meat diet on days one and two. The mushroom-rich diet resulted in higher average stool weight (p = 0.002) and a different fecal microbiota composition compared to the meat diet, with greater abundance of Bacteroidetes (p = 0.0002) and lower abundance of Firmicutes (p = 0.0009). The increase in stool weight and presence of undigested mushrooms in stool suggests that mushroom consumption may impact laxation in healthy adults. Additional research is needed to interpret the health implications of fecal microbiota shifts with mushroom feeding.