Dietary Pectin Research Articles

Nutrition and health effects of pectin: A systematic scoping review of human intervention studies.

Pectin is composed of a group of complex polysaccharides that are naturally found in various plants and are associated with a range of beneficial health effects. Health outcomes from dietary pectin can vary depending on botanical origin, dietary dose and structure of pectin. The objective of this scoping review is to build a comprehensive overview of the current evidence available on intervention studies conducted in humans and to better understand the possible knowledge gaps in terms of structure-function relationships across the different health-related effects. PubMed and Embase databases were searched using PRISMA-ScR guidelines, yielding 141 references (from the initial 3704), representing 134 intervention studies performed between 1961 and 2022 that met inclusion criteria. Studies were divided into six categories, which included gut health, glycaemic response and appetite, fat metabolism, bioavailability of micronutrients, immune response and other topics. Review of these human intervention studies identified a variety of cohort characteristics and populations (life stage, health status, country), sources/types of pectin (i.e. citrus, sugarbeet, apple, other and non-defined), intervention timeframes (from one single intake to 168 d) and doses (0.1-50 g/d) that were tested for health outcomes in people. Gut health, post-prandial glucose regulation and maintenance of blood cholesterol represented the largest categories of studied outcomes. Further research to strengthen the structure-function relationships for pectin with health properties and associated outcomes is warranted and will benefit from a more precise description of physico-chemical characteristics and molecular compositions, such as degree of esterification, weight, degree of branching, viscosity, gel formation and solubility.

Dietary Pectin from Premna microphylla Turcz Leaves Prevents Obesity by Regulating Gut Microbiota and Lipid Metabolism in Mice Fed High-Fat Diet.

The present study was designed to investigate the protective effects of pectin extracted from Premna microphylla Turcz leaves (PTP) against high-fat-diet (HFD)-induced lipid metabolism disorders and gut microbiota dysbiosis in obese mice. PTP was made using the acid extraction method, and it was found to be an acidic pectin that had relative mole percentages of 32.1%, 29.2%, and 26.2% for galacturonic acid, arabinose, and galactose, respectively. The administration of PTP in C57BL/6J mice inhibited the HFD-induced abnormal weight gain, visceral obesity, and dyslipidemia, and also improved insulin sensitivity, as revealed by the improved insulin tolerance and the decreased glucose levels during an insulin sensitivity test. These effects were linked to increased energy expenditure, as demonstrated by the upregulation of thermogenesis-related protein UCP1 expression in the brown adipose tissue (BAT) of PTP-treated mice. 16S rRNA gene sequencing revealed that PTP dramatically improved the HFD-induced gut dysbiosis by lowering the ratio of Firmicutes to Bacteroidetes and the quantity of potentially harmful bacteria. These findings may provide a theoretical basis for us to understand the functions and usages of PTP in alleviating obesity.

Dietary pectin and inulin: A promising adjuvant supplement for collagen-induced arthritis through gut microbiome restoration and CD4+ T cell reconstitution

Dietary strategies rich in fiber have been demonstrated to offer benefits to individuals afflicted with rheumatoid arthritis (RA). However, the specific mechanisms through which a high-fiber diet (HFD) mitigates RA's autoimmunity remain elusive. Herein, we investigate the influence of pectin- and inulin-rich HFD on collagen-induced arthritis (CIA). We establish that HFD significantly alleviates arthritis in CIA mice by regulating the Th17/Treg balance. The rectification of aberrant T cell differentiation by the HFD is linked to the modulation of gut microbiota, augmenting the abundance of butyrate in feces. Concurrently, adding butyrate to the drinking water mirrors the HFD's impact on ameliorating CIA, encompassing arthritis mitigation, regulating intestinal barrier integrity, and restoring the Th17/Treg equilibrium. Butyrate reshapes the metabolic profile of CD4+ T cells in an AMPK-dependent manner. Our research underscores the importance of dietary interventions in rectifying gut microbiota for RA management and offers an explanation of how diet-derived microbial metabolites influence RA's immune-inflammatory-reaction.

Benefits of maternal pectin supplementation in gestation diet on vaginal microbiota of sows and intestinal health of newborn piglets.

Pectin is a proven prebiotic and widely used in human health products. This study aims to assess the impact of dietary pectin supplementation during gestation on sow vaginal microbiota and the offspring's intestinal composition. Thirty sows were randomly allocated to two groups and fed a standard diet (CON) or a standard diet supplemented with 3 g/kg pectin (PEC). Blood, feces, and vaginal swab samples from the sows and blood, intestines issue, and colonic content samples from the offspring were collected and analyzed. The results indicate that the relative abundance of vaginal Lactobacillus was notably enhanced in the PEC group and fecal β-glucuronidase (β-G) activity and plasma 17β-estradiol (E2) concentration were also significantly increased in the PEC group. Newborn piglets were found to host different microbial communities as well. At the phylum level, Proteobacteria dominated in the CON group, and Firmicutes was predominant in the PEC group. Newborn piglets in the PEC group had a lower interleukin-6 (IL-6) concentration in their plasma. The expression of intestinal cytokines of offspring was improved as well. Villus height and villus height/crypt depth (V/C) in the PEC group were extremely higher than those in the CON group. In conclusion, dietary pectin supplementation can be of benefit to both sows and newborn piglets.

A Gestational Pectin Diet Could Improve the Health of Multiparous Sows by Modulating the Gut Microbiota and Cytokine Level during Late Pregnancy.

This study aimed to investigate the effects of the dietary fiber pectin on the gut microbiota and health of parturient sows. A total of 30 parity 5-7, multiparous gestation sows (Large White × Landrace) were randomly assigned to two treatment groups after mating: Con (control, basic diet) and Pec (pectin, 3%). The sows received the two diets during gestation, and all sows were fed the same standard basic diet during lactation. The results of β-diversity showed that the composition of the gut microbiota was different in the Con and Pec groups. Compared with the sows in the Con group, the Pec sows showed a higher abundance of the gut bacteria Clostridium and Romboutsia and a lower abundance of harmful bacteria (Micrococcaceae, Coriobacteriaceae, Dorea, Actinomyces). On the other hand, the SCFA plasma concentration was increased in the Pec group, while pro-inflammatory cytokine (IL-6, IL-1β, and TNF-α) concentrations were decreased. In conclusion, the soluble dietary fiber pectin could improve the reproductive performance and health of sows by increasing the abundance of some commensal bacteria enhancing the metabolite SCFA levels and reducing the pro-inflammatory cytokine plasma levels.

Interactive Effects of Dietary Fiber and Lipid Types Modulate the Predicted Production and Absorption of Cecal and Colorectal Short-Chain Fatty Acids in Growing Pigs

BackgroundHigh-fiber diets are supplemented with lipids to meet the required energy content, but data on the interactions between dietary fiber (DF) and lipid types on gastrointestinal fermentation in pigs are scant. ObjectivesThis study aimed to use a combination of in vivo and in vitro fermentation methodologies to determine the interactive effects of DF and lipid types on short-chain fatty acid (SCFA) production and absorption and organic matter (OM) fermentability in the cecum and colorectal tract of pigs. MethodsEight ileal- and cecal-cannulated Yorkshire barrows were fed either pectin- or cellulose-containing diets that were supplemented with either corn oil or beef tallow in 2 independent Youden squares with a 2 × 2 factorial arrangement of treatments (n = 6). Ileal and cecal digesta were collected, freeze-dried, and fermented using inoculum from fresh cecal digesta and feces, respectively, to determine individual SCFA production and absorption and fermentability of OM. ResultsInteractions (P < 0.001) between DF and lipid types were observed in which the addition of beef tallow decreased the quantity of cecal and colorectal acetic acid production and cecal acetic absorption, cecal butyric production, predicted cecal OM fermentability, and predicted colorectal propionic acid in pectin diets, but the effects were not observed for cellulose diets. The addition of beef tallow increased (P < 0.001) the production of cecal butyric and propionic acids during in vitro fermentation in cellulose diets and apparent total tract digestibility (ATTD) of OM in pectin diets. ConclusionsThe interactions between DF and lipids on gastrointestinal fermentation largely depend on the degree of saturation of fatty acids in dietary lipids. The addition of beef tallow selectively decreased the production and absorption of individual SCFAs in pectin and cellulose diets but increased cecal butyric and propionic acid production in cellulose diets and the ATTD of OM in pectin diets.

Effects of dietary pectin on the growth performance, intestinal barrier, and antioxidant status of juvenile rainbow trout (Oncorhynchus mykiss)

To evaluate the effects of dietary pectin on growth performance, intestinal barrier, and antioxidant status of juvenile rainbow trout (Oncorhynchus mykiss), 10-week feeding trial was conducted. Five isoproteic and isoenergetic diets were formulated to contain 0% (P0), 4% (P4), 8% (P8), and 16% (P16) pectin as well as 0.02% pectinase (PE) at the expense of wheat starch, respectively. Dietary inclusion of 416% pectin linearly promoted the feed intake and growth performance but depressed the feed efficiency, but significant differences were only observed between the P16 and P0 groups. Similarly, dietary inclusion of 816% pectin significantly increased the foregut trypsin and amylase activities but decreased the foregut and midgut sucrase activity. The midgut muc2 gene expression level was significantly down-regulated by the inclusion of 16% pectin. Dietary inclusion of 2% pectin increased the abundance of Proteobacteria and Stenotrophomonas but reduced the abundance of Actinobacteria, Bacteroides and Helicobacter; while the lowest values of observed species, Chao1 and ACE indices of intestinal flora were found in the P8 group. Fish fed with the P8 diet exhibited the lowest plasma catalase and midgut glutathione S-transferase activities as well as malondialdehyde content, but the highest midgut malondialdehyde content. Dietary inclusion of 816% pectin significantly depressed the plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1) and mechanistic target of rapamycin contents as well as alanine aminotransferase activity, the hepatic adenosine monophosphate deaminase and glutamate dehydrogenase (GDH) activities. Dietary treatment with 0.02% pectinase did not affect the growth performance, but depressed the foregut sucrase activity, the midgut amylase and sucrase activities, increased the plasma GH and IGF-1 contents as well as hepatic GDH and aspartate aminotransferase activities. In conclusion, high-dose of dietary pectin (816%) may promote the feed intake and intestinal digestive enzyme activities and thereby improve the growth performance of rainbow trout.

Modulation of pectin on intestinal barrier function via changes in microbial functional potential and bile acid metabolism

Weaning is one of the major factors that cause stress and intestinal infection in infants and in young animals due to an immature intestine and not fully developed immune functions. Pectin (PEC), a prebiotic polysaccharide, has attracted considerable attention in intestinal epithelial signaling and function via modulation of the microbial community. A total of 16 weaned piglets (21-d-old) were randomly assigned into two groups: control group and PEC group. Supplementation of 5% pectin improved intestinal mucosal barrier function by modulating the composition of the bile acid pool in piglets. Specifically, piglets in PEC group had less serum D-lactate content and alkaline phosphatase activity. In the ileum, dietary pectin increased the number of crypt PAS/AB-positive goblet cells and the mRNA expressions of MUC2, ZO-1, and Occludin. Piglets in PEC group displayed a decreased abundance of Enterococcus (2.71 vs. 65.92%), but the abundances of Lactobacillus (30.80 vs. 7.93%), Streptococcus (21.41 vs. 14.81%), and Clostridium_sensu_stricto_1 (28.34 vs. 0.01%) were increased. Elevated concentrations of bile acids especially hyocholic acid species (HCAs) including HCA, HDCA, and THDCA were also observed. Besides, correlation analysis revealed that dietary pectin supplementation may have beneficial effects through stimulation of the crosstalk between gut microbes and bile acid synthesis within the enterohepatic circulation. Thus, dietary pectin supplementation exhibited a further positive effect on the healthy growth and development of weaned piglets. These findings suggest pectin supplementation as the prebiotic is beneficial for gut health and improvement of weaned stress via regulating microbiota and bile acid metabolism.

Dietary pectin attenuates Salmonella typhimurium-induced colitis by modulating the TLR2-NF-κB pathway and intestinal microbiota in mice

The role of dietary pectin on microbial-induced colitis, oxidative status, barrier function, and microbial composition, as well as the underlying mechanisms, is scarce. In this study, we aimed to investigate whether dietary pectin alleviates Salmonella typhimurium-induced colitis in mice. Male C57BL/6J mice fed an isocaloric and isofibrous diet with 7% pectin or cellulose were administered sterile water or Salmonella typhimurium to induce colitis, which is equal to a human food dose of 0.57% (5.68 g/kg). Dietary pectin alleviated Salmonella typhimurium-induced colitis and oxidative stress as shown by the reduced disease activity index score, decreased colon shortening and histological damage score, colonic hydrogen peroxide, malondialdehyde concentrations, and relative mRNA expressions of coenzyme Q-binding protein COQ10 homologue B (Coq10b), Ccl-2, Ccl-3, Ccl-8, Tnf-α, Il-1β, Ifn-γ, Ifn-β, and serum TNF-α protein level. Moreover, pectin administration ameliorated the downregulated colonic abundances of occludin, zonula occludens-1, zonula occludens-2, and the upregulated abundances of TLR2 and p–NF–κB in Salmonella-infected mice. Additionally, 16S rRNA analysis demonstrated that pectin altered the microbial beta-diversity and reduced Salmonella levels. Collectively, pectin ameliorated Salmonella typhimurium-induced colitis, oxidative stress, and tight junction, which may be related to the inactivation of TLR2-NF-κB signalling and reduced abundance of Salmonella.

The Interaction of Dietary Pectin, Inulin, and Psyllium with Copper Nanoparticle Induced Changes to the Cardiovascular System.

We aimed to analyze how supplementation with a standard (recommended, 6.5 mg/kg) or enhanced (two-times higher, 13 mg/kg) dose of copper (Cu), in the form of nanoparticles (NPs) along with dietary intervention via the implementation of diverse types of fiber, affects the cardiovascular system in rats. Nine-week-old male Wistar Han rats (n/group = 10) received, for an additional 6 weeks, a controlled diet with cellulose as dietary fiber and ionic Cu (in the form of carbonate salt). The experimental groups received cellulose, pectin, inulin, and psyllium as dietary fiber, together with CuNPs (6.5 or 13 mg/kg diet). After the experimental feeding, samples of blood, hearts, and thoracic arteries were collected for further analysis. Compared to pectin, and under a standard dose of CuNPs, inulin and psyllium beneficially increased the antioxidant capacity of lipid- and water-soluble compounds in the blood, and decreased heart malondialdehyde. Moreover, pectin decreased heart catalase (CAT) and cyclooxygenase (COX)-2 in the aortic rings compared to inulin and psyllium under standard and enhanced doses of copper. When the dose of CuNPs was enhanced, inulin and psyllium potentiated vasodilation to acetylcholine by up-regulation of COX-2-derived vasodilator prostanoids compared to both cellulose and pectin, and this was modulated with selective inducible nitric oxide synthase (iNOS) inhibitor for psyllium only. Moreover, inulin decreased heart CAT compared to psyllium. Our results suggest that supplementation with dietary fiber may protect the vascular system against potentially harmful metal NPs by modulating the antioxidant mechanisms.

A diet rich in fermentable fiber promotes robust changes in the intestinal microbiota, mitigates intestinal permeability, and attenuates autoimmune uveitis

Therapeutic approaches for noninfectious uveitis have expanded greatly over the past 10 years, but are limited by potential side effects and limited efficacy. Thus, therapeutic approaches that include less toxic, potentially preventative strategies to manage noninfectious uveitis are essential areas of study. Diets rich in fermentable fiber are potentially preventative in various conditions such as metabolic syndrome and type 1 diabetes. We studied the effects of various fermentable dietary fibers in an inducible model of experimental autoimmune uveitis (EAU) and found that they differentially modulated uveitis severity. A high pectin diet was the most protective, reducing clinical disease severity through the induction of regulatory T lymphocytes and the suppression of Th1 and Th17 lymphocytes at peak ocular inflammation in either intestinal or extra-intestinal lymphoid tissues. The high pectin diet also promoted intestinal homeostasis as shown by changes in intestinal morphology and gene expression, as well as intestinal permeability. Pectin-induced modulation of intestinal bacteria appeared to be associated with protective changes in immunophenotype in the intestinal tract, and correlated with reduced uveitis severity. In summary, our current findings support the potential for dietary intervention as a strategy to mitigate noninfectious uveitis severity.

Pectin alleviates the pulmonary inflammatory response induced by PM2.5 from a pig house by modulating intestinal microbiota

This study aimed to investigate whether dietary fiber pectin can alleviate PM2.5-induced pulmonary inflammation and the potential mechanism. PM2.5 samples were collected from a nursery pig house. The mice were divided into three groups: the control group, PM2.5 group and PM2.5 + pectin group. The mice in the PM2.5 group were intratracheally instilled with PM2.5 suspension twice a week for four consecutive weeks, and those in the PM2.5 + pectin group were subject to the same PM2.5 exposure, but fed with a basal diet supplemented with 5% pectin. The results showed that body weight and feed intake were not different among the treatments (p > 0.05). However, supplementation with pectin relieved PM2.5-induced pulmonary inflammation, presenting as slightly restored lung morphology, decreased mRNA expression levels of IL-1β, IL-6 and IL-17 in the lung, decreased MPO content in bronchoalveolar lavage fluid (BLAF), and even decreased protein levels of IL-1β and IL-6 in the serum (p < 0.05). Dietary pectin altered the composition of the intestinal microbiota, increasing the relative abundance of Bacteroidetes and decreasing the ratio of Firmicutes/Bacteroidetes. At the genus level, short-chain fatty acid (SCFA)-producing bacteria, such as Bacteroides, Anaerotruncus, Prevotella 2, Parabacteroides, Ruminococcus 2 and Butyricimonas, were enriched in the PM2.5 +pectin group. Accordingly, dietary pectin increased the concentrations of SCFAs, including acetate, propionate, butyrate and valerate, in mice. In conclusion, dietary fermentable fiber pectin can relieve PM2.5-induced pulmonary inflammation via alteration of intestinal microbiota composition and SCFA production. This study provides a new insight into reducing the health risk associated with PM2.5 exposure.

Studies on the growth, immunomodulation and gut morphometry of Labeo rohita fed pectin

<br />The present study was designed to evaluate the effect of pectin supplemented feeds on the growth, gut morphology and immunology of <i>Labeo rohita</i>. Experimental feeds containing various concentrations of pectin including control (0%), T1 (0.5%), T2 (1.0%), T3 (2.0%), and T4 (4.0%) were administered to <i>L. rohita</i> twice per day at a rate of 3% body weight. There was a significant (<i>P</i> < 0.05) decrease in average final weight, weight gain%, net weight gain and specific growth rate observed in treatment groups in order of control > T1 > T2 > T3 > T4 while feed conversion ratio was significantly (<i>P </i>< 0.05) higher in T4 compared to the other groups T3 > T2 > T1 > control. Immunological parameters of peroxidase, protease and antiprotease (trypsin) showed significant (<i>P </i>< 0.05) results between control and treated groups. Peroxidase activity was significantly (<i>P </i>< 0.05) higher in T4 group fish compared to T3 > T2 > T1 > control group. Total protein, protease and antiprotease activity were significantly (<i>P </i>< 0.05) higher in the control compared to treatment groups T1 > T2 > T3 > T4. An increased level of the non-starch polysaccharide pectin in feed caused acute effects on gut morphometry. Villus length, villus width, and an increase in mucosal folds were abnormal but no significant (<i>P</i> > 0.05) abnormality was observed in the control group. In the submucosal part of the intestine, hyperplasia was shown in loose connective tissues and in adipose tissue cells in the treated groups. In conclusion, dietary pectin supplementation from 0.5% to 4% had negative effects on the growth, immunological parameters and gut histomorphology of <i>L. rohita</i>.

Pectin modulates intestinal immunity in a pig model via regulating the gut microbiota-derived tryptophan metabolite-AhR-IL22 pathway

BackgroundPectin is a heteropolysaccharide that acts as an intestinal immunomodulator, promoting intestinal development and regulating intestinal flora in the gut. However, the relevant mechanisms remain obscure. In this study, pigs were fed a corn-soybean meal-based diet supplemented with either 5% microcrystalline cellulose (MCC) or 5% pectin for 3 weeks, to investigate the metabolites and anti-inflammatory properties of the jejunum.ResultThe results showed that dietary pectin supplementation improved intestinal integrity (Claudin-1, Occludin) and inflammatory response [interleukin (IL)-10], and the expression of proinflammatory cytokines (IL-1β, IL-6, IL-8, TNF-α) was down-regulated in the jejunum. Moreover, pectin supplementation altered the jejunal microbiome and tryptophan-related metabolites in piglets. Pectin specifically increased the abundance of Lactococcus, Enterococcus, and the microbiota-derived metabolites (skatole (ST), 3-indoleacetic acid (IAA), 3-indolepropionic acid (IPA), 5-hydroxyindole-3-acetic acid (HIAA), and tryptamine (Tpm)), which activated the aryl hydrocarbon receptor (AhR) pathway. AhR activation modulates IL-22 and its downstream pathways. Correlation analysis revealed the potential relationship between metabolites and intestinal morphology, intestinal gene expression, and cytokine levels.ConclusionIn conclusion, these results indicated that pectin inhibits the inflammatory response by enhancing the AhR-IL22-signal transducer and activator of transcription 3 signaling pathway, which is activated through tryptophan metabolites.

A266 DIET-BASED THERAPIES FOR INTESTINAL DYSFUNCTION INDUCED BY CLOSTRIDIOIDES DIFFICILE INFECTION

Abstract Background Chronic gut dysfunction occurs in up to 25% of patients following antibiotic-treated C. difficile infection (CDI). We developed a humanized mouse model in which germ free mice colonized with microbiota from patients with severe constipation post-CDI developed slow colonic transit, as a result of damage to the Interstitial Cells of Cajal (ICC) network by pro-inflammatory macrophages. Colonic transit, immune activation and the ICC network normalized after fecal microbiota transplantation using samples from healthy mice, as well after treatment with psyllium fiber. Here we explored the long-term effects of psyllium and evaluated the therapeutic potential of pectin and quercetin in this model. Purpose 1) To investigate the time course of the beneficial effect of psyllium on colonic motility. 2) To explore possible therapeutic properties of flavonoids and pectin. Method Germ-free mice were colonized with microbiota from the post-CDI (PCDI) patient or healthy controls (HC). After 3 weeks, the mice were fed for 4-5 weeks with a control diet or diets with 15% psyllium (PSY), 10% pectin (PCT) or 0.05% quercetin (QCT). To evaluate time course of PSY on motility, control diet was administered for 3-weeks following PSY treatment. The bead expulsion test was used to assess colonic motility. Stool samples were collected for microbial profiling, and short and branched-chain fatty acids (SCFA/BCFA) analysis. Macrophages morphology and counts, and ICC network structure were evaluated by immunohistochemistry. Result(s) Compared to HC microbiota, colonization with post-CDI microbiota induced slow colonic transit in recipient mice, and this was normalized by PSY (n=13; p=0.02). The benefit of PSY was transient as colonic transit slowed following discontinuation of PSY (p=0.001). The changes in colonic transit were paralleled by switch in macrophages phenotype and damage to the ICC network. Additionally, discontinuation of PSY resulted in a return of microbial diversity (p&amp;lt; 0.001), SCFA/BCFA levels (acetic and propionic acid/ iso-butyric and valeric acid) and specific bacterial species abundances, to values seen in untreated mice colonized with post-CDI microbiota. Microbial analysis predicted potential pathways involved in macrophage polarization, including the synthesis of SCFA/BCFA, degradation of inositol and production of acetylglucosamine. PCT also normalized slow intestinal transit in mice colonized with post-CDI microbiota (p=0.003), restored phenotype of infiltrating macrophages, and improved the structural integrity of the ICC network. In contrast, QCT failed to improve gut dysfunction in PCDI mice. Conclusion(s) Our results suggest that the beneficial effects of psyllium in this model are transient. Dietary pectin, but not quercetin, may also serve as a novel treatment strategy to restore colonic motility and immune homeostasis in humans with severe constipation post-CDI. Please acknowledge all funding agencies by checking the applicable boxes below Other Please indicate your source of funding; W. Garfield Weston Foundation Disclosure of Interest None Declared

Pectin Feeding Influences Fecal Bile Acid Excretion, Hepatic Bile Acid and Cholesterol Synthesis and Serum Cholesterol in Rats

This study was designed to investigate the effects of pectin on cholesterol and bile acid metabolism and to elucidate the mechanisms involved in its hypolipidemic effect in rats. The key regulatory enzymes in cholesterol and bile acid metabolism, 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) and cholesterol 7α-hydroxylase, were determined. Circulating, hepatic, and biliary lipid concentrations and fecal bile acid excretion were also measured. Male Wistar rats were fed a fiber-free or a pectin-supplemented (7 g/100 g) diet for 4 wk. Bile flow and the biliary secretion of both bile acids and cholesterol were not significantly different than controls in pectin-fed rats. The addition of pectin to the diet resulted in lower serum and liver cholesterol concentrations (-27 and -17%, respectively). Fecal bile acid excretion (+168%) and the hepatic activity of cholesterol 7α-hydroxylase (+70%) were significantly higher in pectin-fed animals. HMG-CoA reductase activity was also significantly greater (+11%) in the presence of dietary pectin. Results of our study indicate that pectin, by enhancing fecal bile acid excretion, may cause increased hepatic synthesis of bile acids and liver depletion of cholesterol in rats, which results in a higher rate of cholesterol synthesis and reduced serum cholesterol concentrations.

Pectin supplement alleviates gut injury potentially through improving gut microbiota community in piglets.

As pectin is widely used as a food and feed additive due to its tremendous prebiotic potentials for gut health. Yet, the underlying mechanisms associated with its protective effect remain unclear. Twenty-four piglets (Yorkshire × Landrace, 6.77 ± 0.92 kg) were randomly divided into three groups with eight replicates per treatment: (1) Control group (CON), (2) Lipopolysaccharide-challenged group (LPS), (3) Pectin-LPS group (PECL). Piglets were administrated with LPS or saline on d14 and 21 of the experiment. Piglets in each group were fed with corn-soybean meal diets containing 5% citrus pectin or 5% microcrystalline cellulose. Our result showed that pectin alleviated the morphological damage features by restoring the goblet numbers which the pig induced by LPS in the cecum. Besides, compared with the LPS group, pectin supplementation elevated the mRNA expression of tight junction protein [Claudin-1, Claudin-4, and zonula occludens-1 (ZO-1)], mucin (Muc-2), and anti-inflammatory cytokines [interleukin 10 (IL-10), and IL-22]. Whereas pectin downregulated the expression of proinflammatory cytokines (IL-1β, IL-6, IL-18), tumor necrosis factor-&alpha (TNF-α), and NF-κB. What is more, pectin supplementation also significantly increased the abundance of beneficial bacteria (Lactobacillus, Clostridium_sensu_stricto_1, Blautia, and Subdoligranulum), and significantly reduced the abundance of harmful bacteria, such as Streptococcus. Additionally, pectin restored the amount of short-chain fatty acids (SCFAs) after being decreased by LPS (mainly Acetic acid, Propionic acid, and Butyric acid) to alleviate gut injury and improve gut immunity via activating relative receptors (GPR43, GPR109, AhR). Mantel test and correlation analysis also revealed associations between intestinal microbiota and intestinal morphology, and intestinal inflammation in piglets. Taken together, dietary pectin supplementation enhances the gut barrier and improves immunity to ameliorate LPS-induced injury by optimizing gut microbiota and their metabolites.

Effects of Dietary Pectin and Lactobacillus salivarius ATCC 11741 on Growth Performance, Immunocompetence, Gut Microbiota, Antioxidant Capacity, and Disease Resistance in Narrow-Clawed Crayfish, Postantacus leptodactylus.

The present study was conducted to clarify the effects of Lactobacillus salivarius (LS) ATCC 11741 and pectin (PE) on growth performance, digestive enzymes activity, gut microbiota composition, immune parameters, antioxidant defense as well as disease resistance against Aeromonas hydrophila in narrow-clawed crayfish, Postantacus leptodactylus. During 18 weeks trial feeding, 525 narrow-clawed crayfish juvenile (8.07 ± 0.1 g) fed with seven experimental diets including control (basal diet), LS1 (1 × 107 CFU/g), LS2 (1 × 109 CFU/g), PE1 (5 g/kg), PE2 (10 g/kg), LS1PE1 (1 × 107 CFU/g +5 g/kg), and LS2PE2 (1 × 109 CFU/g +10 g/kg). After 18 weeks, growth parameters (final weight, weight gain, and specific growth rate) and feed conversion rate were significantly improved in all treatments (P < 0.05). Besides, diets incorporated with LS1PE1 and LS2PE2 significantly increased the activity of amylase and protease enzymes compared to LS1, LS2, and control groups (P < 0.05). Microbiological analyses revealed that the total heterotrophic bacteria count (TVC) and lactic acid bacteria (LAB) of narrow-clawed crayfish fed diets containing LS1, LS2, LS1PE1, and LS2PE2 were higher than control group. The highest total haemocyte count (THC), large-granular (LGC) and semigranular cells (SGC) count, and hyaline count (HC) was obtained in LS1PE1 (P < 0.05). Similarly, higher immunity activity (lysozyme (LYZ), phenoloxidase (PO), nitroxidesynthetase (NOs), and alkaline phosphatase (AKP)) observed in the LS1PE1 treatment compared to the control group (P < 0.05). The glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity remarkably enhanced in LS1PE1 and LS2PE2, while malondialdehyde (MDA) content reduced in these two treatments. In addition, specimens belonging to LS1, LS2, PE2, LS1PE1, and LS2PE2 groups presented higher resistance against A. hydrophila compared to the control group. In conclusion, feeding narrow-clawed crayfish with synbiotic had higher efficiency on growth parameters, immunocompetence, and disease resistance compared to single consumption of prebiotics and probiotics.

Low methyl-esterified pectin induces abnormal hepatic lipid deposition in largemouth bass, Micropterus salmoides

A 56-day trial investigated the influences of different methyl-esterified pectin on the digestive enzyme activity, lipid metabolism, gut and hepatic morphology, and growth of largemouth bass. Four practical diets with 13.7% crude lipids and 42.5% crude protein were formulated to contain 8% cellulose, two different methyl-esterified pectins (10.9% and 72.3% esterification degree, LMP and HMP), and mixed pectin (MMP, 50% LMP + 50% HMP). Results showed that dietary pectin inclusion has no detrimental influences on fish growth and feed utilization, and upregulated the expression of hepatic lipid synthesis and metabolism-related genes. Specifically, dietary HMP increased intestinal Na+/K+-ATPase and AKP activities, crypt depth, and growth of largemouth bass, whereas dietary LMP increased serum ALT activity and hepatic lipid content. In summary, dietary LMP led to abnormal hepatic lipid deposition by up-regulating the expression of hepatic lipogenesis and lipolysis-related genes, and ultimately induced hepatic impairment in largemouth bass. Conversely, dietary HMP exhibited a growth-improvement effect by improving digestive enzyme activity and intestinal digestive physiology. Our data demonstrated that HMP has better application value than LMP in the aquaculture industry.

Dietary pectin caused great changes in bile acid profiles of Pelteobagrus fulvidraco.

To reveal the impact of dietary fiber (DF) on the bile acid (BA) profiles of fish, yellow catfish (Pelteobagrus fulvidraco) were fed a diet containing 300gkg-1 dextrin (CON diet, control) or pectin (a type of soluble DF, PEC diet) for 7days, and then the BA profiles were analyzed by UHPLC-MS/MS. A total of 26 individuals of BAs were detected in the fish body, with 8, 10, 14, and 22 individuals of BAs detected in the liver, serum, bile, and hindgut digesta, respectively. The conjugated BAs (CBAs) of fish were dominated by taurine CBAs (TCBAs). The concentrations of free BAs (FBAs) and the value of FBAs/CBAs in the bile of fish fed the PEC diet were nearly 5 and 7 times higher, respectively than those in fish fed the CON diet. The value of glycine CBAs/TCBAs in the liver, serum and bile of fish fed the PEC diet was significantly lower, and in the hindgut digesta was higher than that of fish fed the CON diet (P < 0.05). These results suggested that dietary pectin greatly changed the BA profiles of Pelteobagrus fulvidraco, attributed to inhibition of reabsorption of BAs. Therefore, attention should be paid to the impact on BA homeostasis when replacing fishmeal with DF-rich plant ingredients in the fish diet.