Can Diet Alter the Intestinal Barrier Permeability in Healthy People? A Systematic Review.

Dietary factors can modify the function of the intestinal barrier, causing permeability changes. This systematic review analyzed evidence on the link between diet or dietary interventions and changes in intestinal barrier permeability (IBP) in healthy individuals. A systematic search for primary studies was conducted using the virtual databases EMBASE, PubMed, Web of Science, CINAHL, and Scopus. This review adhered to PRISMA 2020 guidelines, assessing the methodological quality using the Newcastle-Ottawa scale for observational studies and ROB 2.0 for randomized clinical trials. Out of 3725 studies recovered, 12 were eligible for review. Chicory inulin and probiotics reduced IBP in adults with a moderate GRADE level of evidence. The opposite result was obtained with fructose, which increased IBP in adults, with a very low GRADE level of evidence. Only intervention studies with different dietary components were found, and few studies evaluated the effect of specific diets on the IBP. Thus, there was no strong evidence that diet or dietary interventions increase or decrease IBP in healthy individuals. Studies on this topic are necessary, with a low risk of bias and good quality of evidence generated, as there is still little knowledge on healthy populations.

Inulin prebiotic ameliorates type 1 diabetes dictating regulatory T cell homing via CCR4 to pancreatic islets and butyrogenic gut microbiota in murine model.

Gut dysbiosis is linked to type 1 diabetes mellitus (T1D). Inulin (INU), a prebiotic, modulates the gut microbiota, promoting beneficial bacteria that produce essential short-chain fatty acids for immune regulation. However, how INU affects T1D remains uncertain. Using a streptozotocin-induced (STZ) mouse model, we studied INU's protective effects. Remarkably, STZ + INU mice resisted T1D, with none developing the disease. They had lower blood glucose, reduced pancreatic inflammation, and normalized serum insulin compared with STZ + SD mice. STZ + INU mice also had enhanced mucus production, abundant Bifidobacterium, Clostridium cluster IV, Akkermansia muciniphila, and increased fecal butyrate. In cecal lymph nodes, we observed fewer CD4+Foxp3+ regulatory T cells expressing CCR4 and more Foxp3+CCR4+ cells in pancreatic islets, with higher CCL17 expression. This phenotype was absent in CCR4-deficient mice on INU. INU supplementation effectively protects against experimental T1D by recruiting CCR4+ regulatory T cells via CCL17 into the pancreas and altering the butyrate-producing microbiota.

Effect of coadministration of Lactiplantibacillus fabifermentans and linear/branched fructans mixtures on the intestinal health of Wistar rats.

A completely randomized experimental design was conducted to evaluate the effect of the coadministration of Lactiplantibacillus fabifermentans (Lpb. fabifermentans) and inulin/agave fructans mixtures on gut microbiota of healthy Wistar rats. Inulin, Agave salmiana fructans or fructan mixtures (1:1) at 12.5 % w/w, and Lpb. fabifermentans at 109 CFU/mL/day were used in the rats' diet for 35 days. Biochemical parameters, short-chain fatty acids (SCFA), structural changes and the bacterial abundance in rats' cecum were evaluated. A significant decrease (p < 0.05) in glucose, cholesterol and triglycerides levels with fructan mixtures combined with Lpb. Fabifermentans was observed. The weight of the small and large intestines, and cecum was higher than the control; no changes were observed in the heart, liver, spleen and kidneys. SCFA concentration mainly, propionate and butyrate was improved (p < 0.05) throughout the gastrointestinal tract in all treatments. Finally, the administration of Lpb. fabifermentans alone or combined with the fructan mixtures promoted an increase in the abundance of cecum intestinal microbiota: Lactobacillus, Bifidobacterium, Prevotella, Blautia, Faecalibacterium, Butyricimonas, Coprococcus, Akkermansia, Methanobrevibacter, Adlercreutzia, Collinsella, Odoribacter, and Roseburia. The inclusion of fructan mixtures in combination with Lpb. fabifermentans could be a good alternative for the development of functional foods that enhance consumer health.

Inulin diet uncovers complex diet-microbiota-immune cell interactions remodeling the gut epithelium.

BACKGROUND: The continuous proliferation of intestinal stem cells followed by their tightly regulated differentiation to epithelial cells is essential for the maintenance of the gut epithelial barrier and its functions. How these processes are tuned by diet and gut microbiome is an important, but poorly understood question. Dietary soluble fibers, such as inulin, are known for their ability to impact the gut bacterial community and gut epithelium, and their consumption has been usually associated with health improvement in mice and humans. In this study, we tested the hypothesis that inulin consumption modifies the composition of colonic bacteria and this impacts intestinal stem cells functions, thus affecting the epithelial structure. METHODS: Mice were fed with a diet containing 5% of the insoluble fiber cellulose or the same diet enriched with an additional 10% of inulin. Using a combination of histochemistry, host cell transcriptomics, 16S microbiome analysis, germ-free, gnotobiotic, and genetically modified mouse models, we analyzed the impact of inulin intake on the colonic epithelium, intestinal bacteria, and the local immune compartment. RESULTS: We show that the consumption of inulin diet alters the colon epithelium by increasing the proliferation of intestinal stem cells, leading to deeper crypts and longer colons. This effect was dependent on the inulin-altered gut microbiota, as no modulations were observed in animals deprived of microbiota, nor in mice fed cellulose-enriched diets. We also describe the pivotal role of γδ T lymphocytes and IL-22 in this microenvironment, as the inulin diet failed to induce epithelium remodeling in mice lacking this T cell population or cytokine, highlighting their importance in the diet-microbiota-epithelium-immune system crosstalk. CONCLUSION: This study indicates that the intake of inulin affects the activity of intestinal stem cells and drives a homeostatic remodeling of the colon epithelium, an effect that requires the gut microbiota, γδ T cells, and the presence of IL-22. Our study indicates complex cross kingdom and cross cell type interactions involved in the adaptation of the colon epithelium to the luminal environment in steady state. Video Abstract.

Agave fructans enhance the effects of fermented milk products on obesity biomarkers: a randomised trial.

Dysbiosis has been implicated in childhood obesity. Oral intake of fermented milk containing Lacticaseibacillus casei strain Shirota preserves gut microbiota (GM) diversity in children and adults. This study was a double-blind trial involving 37 overweight or obese children aged 6-10 years. Children were followed over a 6-week intervention period in which they received different fermented milk products containing L. casei Shirota: 10 in the first group received just L. casei Shirota; 13 received L. casei Shirota with 3 g/day of inulin (L. casei+inulin); and 14 received L. casei Shirota with 3 g/day of fructans from Agave salmiana (L. casei+fructans). Principal component analysis showed the relationship between microbial abundance, GM metabolites, and other obesity-related markers. Supplementation with probiotics and synbiotics improved the HDL-cholesterol levels of overweight and obese children, although no changes in body composition were detected. We observed an increase in butyrate or propionate concentrations in the L. casei+fructans group compared to the end of the intervention (P<0.03). A diminished level of ANGPTL4 within the L. casei+fructans group (P=0.04) was also found, but no differences when lipopolysaccharide-binding protein was evaluated. The FFAR2+ cell frequency decreased between baseline and at the end of 6-week intervention in L. casei+inulin (P=0.02) and L. casei+fructans groups (P=0.04). In contrast, the percentage of CD14+FFAR3+ frequency increased in the same groups (P=0.04). The L. casei Shirota with inulin or fructans modulates GM, which improves the lipid profile and changes at a molecular level, such as expression of FFAR3 and FFAR2, ANGPTL4, propionate, and butyrate. It, therefore, could be considered an interesting therapeutic possibility for treating childhood overweight and obesity. The study was registered at ClinicalTrials.gov (ID: NCT05423015).

Administration of a single dose of lithium ameliorates rhabdomyolysis-associated acute kidney injury in rats.

Rhabdomyolysis is characterized by muscle damage and leads to acute kidney injury (AKI). Clinical and experimental studies suggest that glycogen synthase kinase 3ß (GSK3ß) inhibition protects against AKI basically through its critical role in tubular epithelial cell apoptosis, inflammation and fibrosis. Treatment with a single dose of lithium, an inhibitor of GSK3ß, accelerated recovery of renal function in cisplatin and ischemic/reperfusion-induced AKI models. We aimed to evaluate the efficacy of a single dose of lithium in the treatment of rhabdomyolysis-induced AKI. Male Wistar rats were allocated to four groups: Sham, received saline 0.9% intraperitoneally (IP); lithium (Li), received a single IP injection of lithium chloride (LiCl) 80 mg/kg body weight (BW); glycerol (Gly), received a single dose of glycerol 50% 5 mL/kg BW intramuscular (IM); glycerol plus lithium (Gly+Li), received a single dose of glycerol 50% IM plus LiCl IP injected 2 hours after glycerol administration. After 24 hours, we performed inulin clearance experiments and collected blood / kidney / muscle samples. Gly rats exhibited renal function impairment accompanied by kidney injury, inflammation and alterations in signaling pathways for apoptosis and redox state balance. Gly+Li rats showed a remarkable improvement in renal function as well as kidney injury score, diminished CPK levels and an overstated decrease of renal and muscle GSK3ß protein expression. Furthermore, administration of lithium lowered the amount of macrophage infiltrate, reduced NFκB and caspase renal protein expression and increased the antioxidant component MnSOD. Lithium treatment attenuated renal dysfunction in rhabdomyolysis-associated AKI by improving inulin clearance and reducing CPK levels, inflammation, apoptosis and oxidative stress. These therapeutic effects were due to the inhibition of GSK3ß and possibly associated with a decrease in muscle injury.

Metabolic Modeling and Bidirectional Culturing of Two Gut Microbes Reveal Cross-Feeding Interactions and Protective Effects on Intestinal Cells.

The gut microbiota is constituted by thousands of microbial interactions, some of which correspond to the exchange of metabolic by-products or cross-feeding. Inulin and xylan are two major dietary polysaccharides that are fermented by members of the human gut microbiota, resulting in different metabolic profiles. Here, we integrated community modeling and bidirectional culturing assays to study the metabolic interactions between two gut microbes, Phocaeicola dorei and Lachnoclostridium symbiosum, growing in inulin or xylan, and how they provide a protective effect in cultured cells. P. dorei (previously belonging to the Bacteroides genus) was able to consume inulin and xylan, while L. symposium only used certain inulin fractions to produce butyrate as a major end product. Constrained-based flux simulations of refined genome-scale metabolic models of both microbes predicted high lactate and succinate cross-feeding fluxes between P. dorei and L. symbiosum when growing in each fiber. Bidirectional culture assays in both substrates revealed that L. symbiosum growth increased in the presence of P. dorei. Carbohydrate consumption analyses showed a faster carbohydrate consumption in cocultures compared to monocultures. Lactate and succinate concentrations in bidirectional cocultures were lower than in monocultures, pointing to cross-feeding as initially suggested by the model. Butyrate concentrations were similar across all conditions. Finally, supernatants from both bacteria cultured in xylan in bioreactors significantly reduced tumor necrosis factor-α-induced inflammation in HT-29 cells and exerted a protective effect against the TcdB toxin in Caco-2 epithelial cells. Surprisingly, this effect was not observed in inulin cocultures. Overall, these results highlight the predictive value of metabolic models integrated with microbial culture assays for probing microbial interactions in the gut microbiota. They also provide an example of how metabolic exchange could lead to potential beneficial effects in the host. IMPORTANCE Microbial interactions represent the inner connections in the gut microbiome. By integrating mathematical modeling tools and microbial bidirectional culturing, we determined how two gut commensals engage in the exchange of cross-feeding metabolites, lactate and succinate, for increased growth in two fibers. These interactions underpinned butyrate production in cocultures, resulting in a significant reduction in cellular inflammation and protection against microbial toxins when applied to cellular models.

Inulin addition improved probiotic survival in soy-based fermented beverage.

Currently, the growing demand for non-dairy functional foods leads to the constant development of new products. The objective of the present work was to obtain a soy-based fermented beverage employing the strains Lactiplantibacillus plantarum CIDCA 8327 or Lacticaseibacillus paracasei BGP1 and to analyze the effect of post-fermentation addition of inulin of low or high average polymerization degree on the bacterial resistance. Also, the antimicrobial and antioxidant activity of the fermented soy-based beverages were analyzed. The soy-based matrix was shown to be a suitable substrate for the growth of both lactic acid bacteria, and the fermented beverages obtained presented bioactive properties such us antioxidant activity and bactericidal effect against pathogen microorganisms. The addition of inulin after the fermentation process avoid the hydrolysis and so, preserve its polymerization degree and thus the potential prebiotic effect. The incorporation of inulin to the soy-based fermented beverages increased the bacterial count after 30 days of refrigerated storage up to 8.71 ± 0.15 and 8.41 ± 0.10 log CFU/mL for L. paracasei and L. planatrum respectively. The resistance to the gastrointestinal conditions of the strain L. paracasei BGP1 in the fermented beverage was improved up to 70% when inulin of high polymerization degree was added. Meanwhile the strain L. plantarum CIDCA 8327 showed a survival of 97 and 94% in the fermented beverage added with inulin of low or high polymerization degree, respectively. These results contribute to the development of non-dairy products containing inulin and probiotics and the diversification agri-based functional foods.

Antimicrobial and Antibiofilm Effect of Inulin-Type Fructans, Used in Synbiotic Combination with Lactobacillus spp. Against Candida albicans.

There is great interest in the search for new alternatives to antimicrobial drugs, and the use of prebiotics and probiotics is a promising approach to this problem. This study aimed to assess the effect of inulin-type fructans, used in synbiotic combinations with Lactobacillus paracasei or Lactobacillus plantarum, on the production of short-chain fatty acids and antimicrobial activity against Candida albicans. The inhibition assay using the L. paracasei and L. plantarum supernatants resulting from the metabolization of inulin-type fructans displayed growth inhibition and antibiofilm formation against C. albicans. Inhibition occurred at concentrations of 12.5, 25, and 50% of the L. paracasei supernatant and at a concentration of 50% of the L. plantarum supernatant. The analysis of short-chain fatty acids by gas chromatography showed that lactic acid was the dominating produced metabolite. However, acetic, propionic, and butyric acids were also detected in supernatants from both probiotics. Therefore, the synbiotic formulation of L. paracasei or L. plantarum in the presence of inulin-type fructans constitutes with anticandidal effect is a possible option to produce antifungal drugs or antimicrobial compounds.

Prebiotic effect of fructans from Agave salmiana on probiotic lactic acid bacteria and in children as a supplement for malnutrition.

An imbalanced gut microbiota predisposes the development of nutritional disorders and chronic gastrointestinal diseases. Several studies have shown improvements on the host's health by enhancing the microbiota with prebiotics that stimulate probiotic microorganisms. This study describes the prebiotic effect of fructans from Agave salmiana consumed by children as a supplement for malnutrition. We report the extraction and degree of polymerization of fructans from A. salmiana, food safety and inflammatory analyses, and their effect in vitro on probiotic lactic acid bacteria (LAB). These fructans were included in the diet of 5-year-old normal-weight and malnourished children in double-blind, two-week interventions that compared the effects on their weight, bacterial count, and volatile organic compounds (VOCs). The extracted powdered fructans from A. salmiana had a composition comparable to inulin, were safe for human consumption, and stimulated the growth in vitro of three characteristic LAB. The children who consumed these fructans had a considerable weight gain, an increased number of LAB, and a decreased concentration of VOCs (indicative of less dysbiosis), demonstrating positive effects of this prebiotic on their microbiota, which were more significant in malnourished children. Fructans from A. salmiana induced in malnourished children significant weight gain and improved the functionality of their gut microbiota.

Inulin Improves Diet-Induced Hepatic Steatosis and Increases Intestinal Akkermansia Genus Level.

Hepatic steatosis is characterized by triglyceride accumulation within hepatocytes in response to a high calorie intake, and it may be related to intestinal microbiota disturbances. The prebiotic inulin is a naturally occurring polysaccharide with a high dietary fiber content. Here, we evaluate the effect of inulin on the intestinal microbiota in a non-alcoholic fatty liver disease model. Mice exposed to a standard rodent diet or a fat-enriched diet, were supplemented or not, with inulin. Liver histology was evaluated with oil red O and H&E staining and the intestinal microbiota was determined in mice fecal samples by 16S rRNA sequencing. Inulin treatment effectively prevents liver steatosis in the fat-enriched diet group. We also observed that inulin re-shaped the intestinal microbiota at the phylum level, were Verrucomicrobia genus significantly increased in the fat-diet group; specifically, we observed that Akkermansia muciniphila increased by 5-fold with inulin supplementation. The family Prevotellaceae was also significantly increased in the fat-diet group. Overall, we propose that inulin supplementation in liver steatosis-affected animals, promotes a remodeling in the intestinal microbiota composition, which might regulate lipid metabolism, thus contributing to tackling liver steatosis.

Colonic neuronal loss and delayed motility induced by high-fat diet occur independently of changes in the major groups of microbiota in Swiss mice.

BACKGROUND: Obesity has been linked to gastrointestinal disorders, and the loss of myenteric neurons in the intestine caused by high-fat diets (HFD) has been attributed to changes in microbiota and lipotoxicity. We investigated whether the prebiotic inulin modulates bacterial populations and alleviates neuronal loss in mice fed HFD. METHODS: Swiss mice were fed purified rodent diet or HFD (59% kcal fat), or both diets supplemented with inulin for 17 weeks. Intestinal motility was assessed and a metagenome analysis of the colonic microbiota was performed. The gene expression of inflammatory markers was evaluated, and immunofluorescence was performed for different types of myenteric neurons and glial cells in the distal colon. KEY RESULTS: The HFD caused obesity and delayed colonic motility. The loss of myenteric neurons and glial cells in obese mice affected all of the studied neuronal populations, including neurons positive for myosin-V, neuronal nitric oxide synthase, vasoactive intestinal peptide, and calretinin. Although obese mice supplemented with inulin exhibited improvements in colonic motility, neuronal, and glial cell loss persisted. The HFD did not altered the expression levels of inflammatory cytokines in the intestine or the prevalence of the major groups in microbiota, but inulin increased the proportion of the genus Akkermansia in the obese mice. CONCLUSIONS AND INFERENCES: In Swiss mice, the HFD-induced neuronal loss but did not change the major groups in microbiota. This suggests that, despite the increase in the beneficial bacteria, other factors that are directly linked to excess dietary lipid intake affect the enteric nervous system.

Effect of full-fat goat's milk and prebiotics use on Bifidobacterium BB-12 survival and on the physical properties of spray-dried powders under storage conditions.

The effects of full-fat goat's milk and/or inulin and/or oligofructose, as carrier agents, were investigated to improve the survival rates of Bifidobacterium BB-12, and the physical properties of the microcapsules under storage conditions. On the day of their manufacture, the microcapsules were evaluated for morphology, particle size, and distribution of fat and bifidobacteria. The viability of the bifidobacteria, moisture and fat content, water activity, solubility, bulk and tapped density, flowability, cohesiveness and color properties were evaluated for 120 days at 4 °C and 25 °C. The full-fat goat's milk powder with or without inulin as encapsulating agents showed the highest survival rates of Bifidobacterium BB-12 after spray drying and storage. Considering the bifidobacteria survival, both of these spray-dried powders showed the most desirable physical properties, i.e., lowest water activity and solubility, respectively. Both properties are highlighted for better stability of spray-dried powders, with microcapsules, during storage time. These results are credited to full-fat goat's milk (200 g L-1) and the presence of inulin (100 g L-1), besides the fat content showing a high correlation with the solubility values. The lowest volume occupied by the spray-dried powders was noted when oligofructose was used as the carrier agent. The samples that showed the presence of cracks influenced negatively on the bifidobacteria viability. These cracks were responsible by the greater water escape, resulting in powders with more desirable lower water activity. In relation to the color parameters, lower stability was noted when oligofructose was used, while the best stability was also noted for the powders with full-fat goat's milk and/or inulin. During storage time, the best performance was achieved by the microencapsulation process that used only full-fat goat's milk and/or inulin and storage at 4 °C.

Agavins reverse the metabolic disorders in overweight mice through the increment of short chain fatty acids and hormones.

In this study, the effects of agavins (branched fructans) along with a diet shift on metabolic parameters, short chain fatty acid (SCFA) production and gastrointestinal hormones in overweight mice were established. Male C57BL/6 mice were fed with a standard (ST) or high fat (HF) diet over the course of 5 weeks, with the objective to induce overweightness in the animals, followed by a diet shift (HF_ST) and a diet shift with agavins (HF_ST + A) or inulin (HF_ST + O) for 5 additional weeks. After the first 5 weeks, the HF group showed a 30% body weight gain and an increase in glucose, triglyceride and cholesterol concentrations of 9%, 79% and 38% respectively when compared to the ST group (P < 0.05). Only the overweight mice that received agavins or inulin in their diets reversed the metabolic disorders induced by consumption of the HF diet, reaching the values very close to those of the ST group (P < 0.05). Furthermore, the consumption of agavins or inulin led to higher SCFA concentrations in the gut and modulated hormones such as GLP-1 and leptin involved in food intake regulation (P < 0.05). These findings demonstrate that a change of diet and fructan consumption such as agavins is a good alternative to increase weight loss and to improve the metabolic disorders associated with being overweight.

Isolation and prebiotic activity of inulin-type fructan extracted from Pfaffia glomerata (Spreng) Pedersen roots.

Pfaffia glomerata (Amaranthaceae) is popularly known as "Brazilian ginseng." Previous studies have shown that fructose is the major carbohydrate component present in its roots. Inulin-type fructans, polymers of fructose, are the most widespread and researched prebiotics. Here, we isolated and chemically characterized inulin extracted from P. glomerata roots and investigated its potential prebiotic effect. Fructans were isolated and their structures were determined using colorimetric, chromatography, polarimetry, and spectroscopic analysis. The degree of polymerization (DP) was determined, and an in vitro prebiotic test was performed. The structure of inulin was confirmed by chromatography and spectroscopic analysis and through comparison with existing data. Representatives from the genera Lactobacillus and Bifidobacterium utilized inulin from P. glomerata, because growth was significantly stimulated, while this ability is strain specific. The results indicated that inulin extracted from P. glomerata roots represents a promising new source of inulin-type prebiotics.

Yacon-Based Product in the Modulation of Intestinal Constipation.

This study aimed to assess the effects of a yacon-based product (YBP) on constipation in adults, including the elderly. Forty-eight individuals were recruited and divided into equal intervention groups named the test and control groups. The YBP (test) and the control (maltodextrin) were dissolved in commercial orange juice. The volunteers for the YBP/test group consumed, on a daily basis, orange juice containing 10 g fructooligosaccharide (FOS)/inulin per day. The control group consumed, on a daily basis, orange juice containing 25 g of maltodextrin. The study had a span of 30 days. We evaluated the participants' frequency of evacuation, consistency of the feces, constipation score, abdominal symptoms (flatulence, pain, and abdominal strain), and effects upon the microbiota, pH, lactate, and short-chain fatty acids (SCFAs) of the feces. The study showed an increased number of evacuations after the consumption of the YBP as well as an improvement in the consistency of the feces and a reduction in the constipation score. After 30 days of intervention, the group that consumed the YBP showed higher counts of Bifidobacterium, lower Clostridium and enterobacteria counts, and lower fecal pH. In relation to SCFAs, no significant change was found after the intervention. However, the lactate concentration was higher in the test group when compared to the post-treatment control group. The YBP was effective in improving constipation symptoms; not only was its functional characteristic in reducing constipation symptoms evident but it also demonstrated usefulness as a potential therapy.

Evaluation of the antimutagenic activity and mode of action of the fructooligosaccharide inulin in the meristematic cells of Allium cepa culture.

This study evaluated the mutagenicity and antimutagenicity of inulin in a chromosomal aberration assay in cultures of the meristematic cells of Allium cepa. The treatments evaluated were as follows: negative control--seed germination in distilled water; positive control--aqueous solution of methyl methanesulfonate (10 µg/mL MMS); mutagenicity--aqueous solutions of inulin (0.015, 0.15, and 1.50 µg/mL); and antimutagenicity--associations between MMS and the different inulin concentrations. The antimutagenicity protocols established were pre-treatment, simultaneous simple, simultaneous with pre-incubation, and post-treatment. The damage reduction percentage (DR%) was 43.56, 27.77, and 55.92% for the pre-treatment; -31.11, 18.51, and 7.03% for the simultaneous simple; 30.43, 19.12, and 21.11% for the simultaneous with pre-incubation; and 64.07, 42.96, and 53.70% for the post-treatment. The results indicated that the most effective treatment for inhibiting damages caused by MMS was the post-treatment, which was followed by the pre-treatment, suggesting activity by bioantimutagenesis and desmutagenesis. The Allium cepa assay was demonstrated to be a good screening test for this type of activity because it is easy to perform, has a low cost, and shows DR% that is comparable to that reported studies that evaluated the prevention of DNA damage in mammals by inulin.

Single or combined effects of Lactobacillus sakei and inulin on growth, non-specific immunity and IgM expression in leopard grouper (Mycteroperca rosacea).

The aim of this study was to evaluate the single or combined effects of Lactobacillus sakei with inulin suitable for immunological in vivo studies in farmed fish. By in vitro assays, L. sakei strain 5-4 showed antibacterial activities against all assayed fish pathogens (except the Vibrio harveyi strain CAIM-1793). L. sakei was able to survive at high fish bile concentrations. Fermentation of the agave inulin resulted in a large increase in number of lactobacilli. For the in vivo study, fish were fed for 8 weeks four practical diets: control diet (control), L. sakei 5-4 (10(7) CFU/g), inulin (1% or 10 g/kg) and L. sakei + inulin (10(7) CFU/g + 10 g/kg). The weight gain showed clearly the synergistic effect of L. sakei 5-4 and inulin at 6 and 8 weeks of treatments. Leopard grouper fed with L. sakei alone or combined with inulin have significantly increased the assayed physiological and humoral immune parameters. By real-time PCR assays, the mRNA transcripts of immunoglobulin M (IgM) were found to be higher expressed in intestine, head kidney, mucus, gill, spleen and skin. Moreover, mRNA expression levels of IgM in head kidney and anterior intestine were measured by real-time PCR. L. sakei 5-4 and L. sakei + inulin supplemented diet up-regulated the expression of IgM at week 4 and 8 in intestine and head kidney, respectively. These results support the idea that the L. sakei 5-4 alone or combined with agave inulin improved growth performance and stimulates the immune system of leopard grouper.

Evaluation of the antimutagenic and anticarcinogenic effects of inulin in vivo.

The incidence of colorectal cancer is growing worldwide. The characterization of compounds present in the human diet that can prevent the occurrence of colorectal tumors is vital. The oligosaccharide inulin is such a compound. The aim of this study was to evaluate the antigenotoxic, antimutagenic and anticarcinogenic effects of inulin in vivo. Our study is based on 3 assays that are widely used to evaluate chemoprevention (comet assay, micronucleus assay, and aberrant crypt focus assay) and tests 4 protocols of treatment with inulin (pre-treatment, simultaneous, post-treatment, and pre + continuous). Experiments were carried out in Swiss male mice of reproductive age. In order to induce DNA damage, we used the pro-carcinogenic agent 1,2-dimethylhydrazine. Inulin was administered orally at a concentration of 50 mg/kg body weight following the protocols mentioned above. Inulin was not administered to the control groups. Our data from the micronucleus assay reveal antimutagenic effects of inulin in all protocols. The percentage of inulin-induced damage reduction ranged from 47.25 to 141.75% across protocols. These data suggest that inulin could act through desmutagenic and bio-antimutagenic mechanisms. The anticarcinogenic activity (aberrant crypt focus assay) of inulin was observed in all protocols and the percentages of damage reduction ranged from 55.78 to 87.56% across protocols. Further tests, including human trials, will be necessary before this functional food can be proven to be effective in the prevention and treatment of colon cancer.

Influence of fat replacement by inulin on rheological properties, kinetics of rennet milk coagulation, and syneresis of milk gels.

The objective of this study was to evaluate the effect of inulin as a fat replacer on the rheological properties, coagulation kinetics, and syneresis of milk gels. A randomized factorial design, replicated 3 times, with 3 inulin concentrations (0, 3, and 6%), 2 levels of fat (<0.2 and 1.5%), and 3 coagulation temperatures (27, 32, and 37°C) was used. The coagulation process was monitored using near-infrared spectrometry, small amplitude oscillatory rheometry, and visual coagulation indexes. The syneresis was evaluated by volumetric methods. Inulin addition increased the rates of aggregation and curd firming reactions in the casein gels. The observed effect, which was more evident on the aggregation reaction, depended on the concentration of inulin and the coagulation temperature. Addition of 6% inulin reduced the clotting time by approximately 26% and the time at which the gel reached a storage modulus equal to 30 Pa by approximately 36%. The optical parameter R'max, defined as the maximum value of change in light backscatter profile/change in time (where R' = dR/dt), was used to calculate an approximation of the temperature coefficients (Q10) for milk coagulation. Increasing fat concentration induced a consistent increase in all the optical, rheological, and visual parameters studied, although the observed trend was not statistically significant. The addition of inulin at a level of 6% produced a reduction in syneresis and increased the curd yield by approximately 30%. It was concluded that the addition of inulin affects the kinetics of milk coagulation and the cutting time and, therefore, the use of inline sensors such as near-infrared spectrometry may be necessary for optimal process control.