Effect on components of the intestinal microflora and plasma neuropeptide levels of feeding Lactobacillus delbrueckii, Bifidobacterium lactis, and inulin to adult and elderly rats

Supplementation with soluble or insoluble rice-bran fibers increases short-chain fatty acid producing bacteria in the gut microbiota in vitro

Introduction

Studies have shown that a diet high in fiber and prebiotics has a positive impact on human health due largely to the fermentation of these compounds by the gut microbiota. One underutilized source of fiber may be rice bran, a waste product of rice processing that is used most frequently as an additive to livestock feed but may be a good source of fibers and other phenolic compounds as a human diet supplement. Previous studies focused on specific compounds extracted from rice bran showed that soluble fibers extracted from rice bran can improve glucose response and reduce weight gain in mouse models. However, less is known about changes in the human gut microbiota in response to regular rice bran consumption.

Methods

In this study, we used a Simulator of the Human Intestinal Microbial Ecology (SHIME®) to cultivate the human gut microbiota of 3 different donors in conditions containing either soluble or insoluble fiber fractions from rice bran. Using 16S rRNA amplicon sequencing and targeted metabolomics via Gas Chromatography-Mass Spectrometry, we explored how gut microbial communities developed provided different supplemental fiber sources.

Results

We found that insoluble and soluble fiber fractions increased short-chain fatty acid production, indicating that both fractions were fermented. However, there were differences in response between donors, for example the gut microbiota from donor 1 increased acetic acid production with both fiber types compared with control; whereas for donors 2 and 3, butanoic acid production increased with ISF and SF supplementation. Both soluble and insoluble rice bran fractions increased the abundance of Bifidobacterium and Lachnospiraceae taxa.

Discussion

Overall, analysis of the effect of soluble and insoluble rice bran fractions on the human in vitro gut microbiota and the metabolites produced revealed individually variant responses to these prebiotics.

Regulation of colonic neuropeptide Y expression by the gut microbiome in patients with ulcerative colitis and its association with anxiety- and depression-like behavior in mice

Patients with inflammatory bowel disease (IBD), including ulcerative colitis (UC), show an increased incidence of anxiety and depression; however, the association between UC-associated psychiatric disorders and the gut microbiota is unclear. This study aimed to examine whether gut microbiota from patients with UC can alter colonic gene expression, leading to anxiety- and depression-like behavior in mice receiving fecal microbiota transplantation (FMT). RNA sequencing transcriptome analyses revealed a difference in colonic gene expression between mice receiving FMT from patients with UC (UC-FMT mice) and those receiving FMT from healthy controls (HC-FMT mice). Gene ontology analysis revealed the downregulation of neuropeptide signaling pathways, including neuropeptide Y (NPY) expression, in the colons of UC-FMT mice. The protein levels of NPY also decreased in the colon and plasma of UC-FMT mice compared to those in HC-FMT mice. The oral administration of Enterococcus mundtii (EM), a bacterium isolated from the feces of patients with UC, reduced NPY expression in the colons of mice and induced intestinal inflammation, anxiety, and depression-like behavior. Reduced NPY protein levels were also observed in the plasma and hippocampus of EM-treated mice. Intraperitoneal administration of NPY significantly alleviated anxiety- and depressive-like behaviors induced by EM in mice. Capsular polysaccharide in EM was associated with EM-induced NPY downregulation in the colon. Analysis of Gene Expression Omnibus datasets showed markedly reduced NPY expression in the inflamed colons of patients with UC compared with that in the colons of healthy controls. In summary, EM-induced reduction in the colonic expression of NPY may be associated with a decrease in hippocampal NPY and anxiety- and depression-like behavior in mice.

Effects of prebiotics in combination with probiotics on intestinal hydrolase activity, microbial population and immunological biomarkers in SD rats fed an AIN-93G diet

BACKGROUND

Gastrointestinal microbiota, which comprises hundreds of different types of microbes, biologically plays crucial roles in the host's health. Probiotics (PRO) did not always have a positive benefit on the host, depending on strains of microbes and the physiochemical properties of prebiotics (PRE), indicating that the properties of PRE in combination with PRO might have different effects on the gut ecology. The aim of this study was to assess the effects of insoluble or soluble PRE with PRO on intestinal digestive hydrolase, the fecal microbes, and immunological biomarkers in SD rats fed an AIN-93G diet.

RESULTS

Forty, 8-week-old SD rats were randomly assigned to 4 groups with 10 replicates in each; cellulose (CELL), cellulose + probiotics (CELPRO), oatmeal (OATS), and oatmeal + probiotics (OATPRO) groups. After 4-week feeding trial, rats were treated with saline or lipopolysaccharide (LPS, 1 mg/kg) to examine the alleviating effects of PRO and PRE on immunological responses. There was a significant (p < 0.05) decrease in feed intake of rats fed the oatmeal supplemented diet without affecting growth performance. Blood triglyceride was significantly (p < 0.05) decreased in rats fed the oatmeal diet, and aspartate aminotransferase (AST) was significantly (p < 0.05) decreased in rats fed the PRO supplemented diet. Intestinal maltase, sucrose, and lactase activities were significantly (p < 0.05) higher in rats fed PRO compared with rats not fed PRO. Rats fed the oatmeal showed a significant (p < 0.01) increase in the fecal colony forming units (CFU) of Lactobacillus plantarum, Bacillus subtilis, and Saccharomyces cerevisiae compared with those fed cellulose. LPS-treated rats fed PRO showed a significant (p < 0.05) increase in blood secretory immunoglobulin A (sIgA) compared with those not fed PRO. The LPS-treated rats fed PRO resulted in decreased (p < 0.05) blood IL-6 compared with those not fed PRO, indicating that a dietary PRO alleviated inflammatory response in LPS-treated rats.

CONCLUSIONS

Dietary oatmeal increased fecal microbes, and PRO supplement resulted in increased intestinal hydrolase and immune functions of the host, demonstrating that soluble PRE with supplemented with PRO could be a more bioactive combination of synbiotics in SD rats.

Acute and short-term effects of Lactobacillus paracasei subsp. paracasei 431 and inulin intake on appetite control and dietary intake: A two-phases randomized, double blind, placebo-controlled study

This study aims to examine the acute and short-term effects of prebiotics, probiotics, and their combination on appetite, energy intake and satiety related hormones in two phases. The first phase was a randomized, double blind, placebo controlled crossover study. Prebiotic (16 g inulin), probiotic (Lactobacillus paracasei subsp. paracasei 431 (L. casei 431) (>10⁶ cfu/ml), synbiotic (their combination) and control (16 g maltodextrin) dairy drinks were consumed by 16 healthy men with a standard breakfast on four separate test days, and the following satiety responses and ad libitum food intake at lunch and over 24 h were assessed. In the second phase, the effects of 21 days of synbiotic (n = 10) or control (n = 11) drink consumption on appetite sensation, energy intake, serum glucose, insulin, peptide YY, ghrelin, obestatin and adiponectin concentration were assessed in a randomized double-blind placebo-controlled design. In the first phase, energy intake values during ad libitum lunch were the lowest in the prebiotic drink, followed by probiotic, synbiotic and control drinks, respectively (p = 0.017); also the rest of the day and 24-h dietary energy intake was lower by prebiotic and probiotic drinks compared to the control drink (p < 0.05 for each). For short-term effects, no significant difference in anthropometric measurements, hunger-satiety scores and serum glucose, insulin, PYY, ghrelin, obestatin and adiponectin concentrations were recorded. Despite the potential of prebiotics and probiotics to reduce energy intake, further studies are required for a better understanding of their role in satiety related mechanisms.

Dietary inclusion of multispecies probiotics to reduce the severity of post-weaning diarrhea caused by Escherichia coli F18+ in pigs

This study was aimed to determine the efficacy of multispecies probiotics in reducing the severity of post-weaning diarrhea caused by enterotoxigenic Escherichia coli (ETEC) F18⁺ on newly weaned pigs. Thirty-two pigs (16 barrows and 16 gilts, BW = 6.99 ± 0.33 kg) at 21 d of age were individually allotted in a randomized complete block design with 2 × 2 factorial arrangement of treatments. Pigs were selected from sows not infected previously and not vaccinated against ETEC. Pigs were fed experimental diets for 25 d based on 10 d phase 1 and 15 d phase 2. The factors were ETEC challenge (oral inoculation of saline solution or E. coli F18⁺ at 2 × 10⁹ CFU) and probiotics (none or multispecies probiotics 0.15% and 0.10% for phase 1 and 2, respectively). Body weight and feed intake were measured on d 5, 9, 13, 19, and 25. Fecal scores were measured daily. Blood samples were taken on d 19 and 24. On d 25, all pigs were euthanized to obtain samples of digesta, intestinal tissues, and spleen. The tumor necrosis factor alpha (TNFα), malondialdehyde (MDA), peptide YY (PYY), and neuropeptide Y (NPY) were measured in serum and intestinal tissue. Data were analyzed using the MIXED procedure of SAS. The fecal score of pigs was increased (P < 0.05) by ETEC challenge at the post–challenge period. The ETEC challenge decreased (P < 0.05) jejunal villus height and crypt depth, tended to increase (P = 0.056) jejunal TNFα, increased (P < 0.05) ileal crypt depth, and decreased (P < 0.05) serum NPY. The probiotics decreased (P < 0.05) serum TNFα, tended to reduce (P = 0.064) jejunal MDA, tended to increase (P = 0.092) serum PYY, and increased (P < 0.05) jejunal villus height, and especially villus height-to-crypt depth ratio in challenged pigs. Growth performance of pigs were not affected by ETEC challenge, whereas the probiotics increased (P < 0.05) ADG and ADFI and tended to increase (P = 0.069) G:F ratio. In conclusion, ETEC F18⁺ challenge caused diarrhea, intestinal inflammation and morphological damages without affecting the growth performance. The multispecies probiotics enhanced growth performance by reducing intestinal inflammation, oxidative stress, morphological damages.

The combined effects of probiotics and restricted calorie diet on the anthropometric indices, eating behavior, and hormone levels of obese women with food addiction a randomized clinical trial

BACKGROUND AND AIM

Food addiction (FA) is an important contributor to obesity. Alterations in gut microbiota (GM) diversity and composition have also been proposed to play a pivotal role in obesity pathogenesis. This trial aimed to assess the effects of probiotic supplementation on the anthropometric indices, eating behavior, and hormone levels of obese women with FA.

METHODS

This randomized, double-blind, placebo-controlled clinical trial was conducted among obese women with FA. Participants (n = 62) received a restricted calorie diet (RCD) plus either probiotic, or placebo for 12 weeks. Anthropometric measurements, biochemical markers, eating behavior and appetite were assessed during the study period.

RESULTS

Probiotics administration significantly reduced weight, body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), body fat percentage (BFP), and trunk fat percentage (TFP) compared to the placebo group (p < 0.001). Also, a significant improvement was observed in eating behavior in the probiotic group compared to the placebo group (p < 0.001).Serum levels of oxytocin increased and NPY decreased significantly in the probiotic group compared to the placebo group (p = 0.02, p = 0.002, respectively). Moreover, leptin level significantly decreased in the probiotic group compared to the baseline values (p < 0.001), while probiotics did not cause a greater significant reduction in leptin level, compared to the placebo group.

CONCLUSION

Multi-probiotic supplementation may have beneficial effects on anthropometric indices, eating behavior, and some appetite-regulating hormones in obese women with FA.Trial registration: Iranian Registry of Clinical Trials identifier: IRCT20131228015968N5.

Bifidobacterium lactis BB-12 Attenuates Macrophage Aging Induced by D-Galactose and Promotes M2 Macrophage Polarization

Immunosenescence comprises a set of dynamic changes occurring in innate and adaptive immune systems, and macrophage aging plays an important role in innate and adaptive immunosenescence. However, function and polarization changes in aging macrophages have not been fully evaluated, and no effective method for delaying macrophage senescence is currently available. The results of this study reveal that D-galactose (D-gal) can promote J774A.1 macrophage senescence and induce macrophage M1 polarization differentiation. Bifidobacterium lactis BB-12 can significantly inhibit J774A.1 macrophage senescence induced by D-gal. IL-6 and IL-12 levels in the BB-12 groups remarkably decreased compared with that in the D-gal group, and the M2 marker, IL-10, and Arg-1 mRNA levels increased in the BB-12 group. BB-12 inhibited the expression of p-signal transducer and activator of transcription 1 (STAT1) and promoted p-STAT6 expression. In summary, the present study indicates that BB-12 can attenuate the J774A.1 macrophage senescence and induce M2 macrophage polarization, thereby indicating the potential of BB-12 to slow down immunosenescence and inflamm-aging.

Prebiotics and probiotics as potential therapy for cognitive impairment

Cognitive functions, such as learning and memory, may be impaired during aging. Age-related cognitive impairment is associated with selective neuronal loss, oxidative changes that lead to microglia activation and neuroinflammation. In addition, it is associated to alteration reduction in trophic factors affecting neurogenesis and synaptic plasticity. In recent years, attention has been paid to the relationship between gut microbiota and brain. In aging, there is an alteration in microbiota, gut microbiota diversity is perturbed with an increase in pathogenic bacteria at the expense of beneficial ones. Dysbiosis may lead to chronic inflammation, and a decrease in bacteria metabolites such as short-chain fatty acids which have been related to an upregulation of neurotrophic factors. Supplementation with prebiotics and probiotics can modulate gut microbiota, returning it to a more physiological state; thus, they may be considered as a possible treatment for age-related cognitive impairment.

Effects of Diethyl Phosphate, a Non-Specific Metabolite of Organophosphorus Pesticides, on Serum Lipid, Hormones, Inflammation, and Gut Microbiota

Organophosphorus pesticides (OPs) can be metabolized to diethyl phosphate (DEP) in the gut environment, which may affect the immune and endocrine systems and the microbiota. Correlations between OPs and diseases have been established by epidemiological studies, mainly based on the contents of their metabolites, including DEP, in the serum or urine. However, the effects of DEP require further study. Therefore, in this study, adult male rats were exposed to 0.08 or 0.13 mg/kg DEP for 20 weeks. Serum levels of hormones, lipids, and inflammatory cytokines as well as gut microbiota were measured. DEP significantly enriched opportunistic pathogens, including Paraprevotella, Parabacteroides, Alloprevotella, and Helicobacter, leading to a decrease in interleukin-6 (IL-6). Exposure to the high dose of DEP enriched the butyrate-producing genera, Alloprevotella and Intestinimonas, leading to an increase in estradiol and a resulting decrease in total triglycerides (TGs) and low-density lipoprotein cholesterol (LDL-C); meanwhile, DEP-induced increases in peptide tyrosine‒tyrosine (PYY) and ghrelin were attributed to the enrichment of short-chain fatty acid-producing Clostridium sensu stricto 1 and Lactobacillus. These findings indicate that measuring the effects of DEP is not a proxy for measuring the effects of its parent compounds.

Intestinal Sensing by Gut Microbiota: Targeting Gut Peptides

There are more than 2 billion overweight and obese individuals worldwide, surpassing for the first time, the number of people affected by undernutrition. Obesity and its comorbidities inflict a heavy burden on the global economies and have become a serious threat to individuals' wellbeing with no immediate cure available. The causes of obesity are manifold, involving several factors including physiological, metabolic, neural, psychosocial, economic, genetics and the environment, among others. Recent advances in genome sequencing and metagenomic profiling have added another dimension to this complexity by implicating the gut microbiota as an important player in energy regulation and the development of obesity. As such, accumulating evidence demonstrate the impact of the gut microbiota on body weight, adiposity, glucose, lipid metabolism, and metabolic syndrome. This also includes the role of microbiota as a modulatory signal either directly or through its bioactive metabolites on intestinal lumen by releasing chemosensing factors known to have a major role in controlling food intake and regulating body weight. The importance of gut signaling by microbiota signaling is further highlighted by the presence of taste and nutrient receptors on the intestinal epithelium activated by the microbial degradation products as well as their role in release of peptides hormones controlling appetite and energy homeostasis. This review present evidence on how gut microbiota interacts with intestinal chemosensing and modulates the release and activity of gut peptides, particularly GLP-1 and PYY.

Supplementation of Lactobacillus plantarum Improves Markers of Metabolic Dysfunction Induced by a High Fat Diet

Obesity is a prevalent chronic condition in many developed and developing nations that raises the risk for developing heart disease, stroke, and diabetes. Previous studies have shown that consuming particular probiotic strains of Lactobacillus is associated with improvement in the obese and diabetic phenotype; however, the mechanisms of these beneficial effects are not well understood. In this study, C57BL/6J male mice were fed a lard-based high fat diet for 15 weeks with Lactobacillus plantarum supplementation NCIMB8826 (Lp) between weeks 10 and 15 ( n = 10 per group). Systemic metabolic effects of supplementation were analyzed by NMR metabolomics, protein expression assays, gene transcript quantification, and 16S rRNA marker gene sequencing. Body and organ weights were not significantly different with Lp supplementation, and no microbiota community structure changes were observed in the cecum; however, L. plantarum numbers were increased in the treatment group according to culture-based and 16S rRNA gene quantification. Significant differences in metabolite and protein concentrations (serum, liver, and colon), gene expression (ileum and adipose), and cytokines (colon) were observed between groups with increases in the gene expression of tight junction proteins in the ileum and cecum and improvement of some markers of glucose homeostasis in blood and tissue with Lp supplementation. These results indicate Lp supplementation impacts systemic metabolism and immune signaling before phenotypic changes and without large-scale changes to the microbiome. This study supports the notion that Lp is a beneficial probiotic, even in the context of a high fat diet.

Oral supplements of inulin during gestation offsets rotenone-induced oxidative impairments and neurotoxicity in maternal and prenatal rat brain

Environmental insults including pesticide exposure and their entry into the immature brain are of increased concern due to their developmental neurotoxicity. Several lines of evidence suggest that maternal gut microbiota influences in utero fetal development via modulation of host's microbial composition with prebiotics. Hence we examined the hypothesis if inulin (IN) supplements during pregnancy in rats possess the potential to alleviate brain oxidative response and mitochondrial deficits employing a developmental model of rotenone (ROT) neurotoxicity. Initially, pregnant Sprague-Dawley rats were gavaged during gestational days (GDs) 6-19 with 0 (control), 10 (low), 30 (mid) or 50 (high) mg/kg bw/day of ROT to recapitulate developmental effects on general fetotoxicity (assessed by the number of fetuses, fetal body and placental weights), markers of oxidative stress and cholinergic activities in maternal brain regions and whole fetal-brain. Secondly, dams orally supplemented with inulin (2×/day, 2 g/kg/bw) on GD 0-21 were administered ROT (50 mg/kg, GD 6-19). IN supplements increased maternal cecal bacterial numbers that significantly corresponded with improved exploratory-related behavior among ROT administered rats. In addition, IN supplements improved fetal and placental weight on GD 19. IN diminished gestational ROT-induced increased reactive oxygen species levels, protein and lipid peroxidation biomarkers, and cholinesterase activity in maternal brain regions (cortex, cerebellum, and striatum) and fetal brain. Moreover, in the maternal cortex, mitochondrial assessment revealed IN protected against ROT-induced reduction in NADH cytochrome c oxidoreductase and ATPase activities. These data suggest a potential role for indigestible oligosaccharides in reducing oxidative stress-mediated developmental origins of neurodegenerative disorders.

The Effects of Synbiotic Supplementation on Body Mass Index, Metabolic and Inflammatory Biomarkers, and Appetite in Patients with Metabolic Syndrome: A Triple-Blind Randomized Controlled Trial

It has been shown recently that metabolic syndrome is associated with gut dysbiosis. The gut microbiota may be the main target for prevention or treatment of metabolic syndrome. We investigated the effects of synbiotic supplementation on metabolic syndrome. In this triple-blinded clinical trial, 46 Iranian patients with metabolic syndrome, from both sexes, aged 25-70 years, who fulfilled inclusion criteria were randomly categorized to receive either the synbiotic or a placebo capsule, twice a day for three months, plus a weight-loss diet using stratified random sampling based on body mass index (BMI). Each synbiotic capsule consisted of seven strains probiotic bacteria (2× 10⁸) plus fructooligosaccharide as a prebiotic. Anthropometric measurements and biochemical tests were assessed at baseline and at the end of week 12 for fasting blood sugar (FBS), insulin, lipid profile, high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), peptide YY (PYY), and glucagon-like peptide-1 (GLP-1). The mean changes of weight, BMI, FBS, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), and GLP-1 between the two groups was statistically significant (p < .001). Furthermore, peptide YY (PYY) increased significantly in the synbiotic group (p ≤ .05). The trend of weight loss in the synbiotic group was significant until the end of the study (p < .001) while it stopped at week 6 in the placebo group. Synbiotic treatment may improve the status of BMI, FBS, insulin resistance, HOMA-IR, GLP-1, and PYY in patients with metabolic syndrome.

Independent and Combined Effects of Lactitol, Polydextrose, and Bacteroides thetaiotaomicron on Postprandial Metabolism and Body Weight in Rats Fed a High-Fat Diet

Obesity is related to the consumption of energy-dense foods in addition to changes in the microbiome where a higher abundance of gut Bacteroidetes can be found in lean subjects or after weight loss. Lactitol, a sweet-tasting sugar alcohol, is a common sugar-replacement in foods. Polydextrose (PDX), a highly branched glucose polymer, is known to reduce energy intake. Here, we test if the combined effects of lactitol or PDX in combination with Bacteroides species will have a beneficial metabolic response in rats fed a high-fat (HF) diet. A total of 175 male Wistar rats were fed either a LF or HF diet. Bacteroides thetaiotaomicron (10¹⁰ bacteria/animal/day) was orally administered with or without lactitol (1.6−2 g/animal/day) or PDX (2 g/animal/day) for 8 days. Postprandial blood samples, cecal digesta, and feces were collected on the last day. Measurements included: body weight, feed consumption, cecal short-chain fatty acids, fecal dry matter and heat value, blood glucose, insulin, triglyceride, and satiety hormone concentrations. Lactitol and PDX decreased the mean body weight when administered with B. thetaiotaomicron or when lactitol was administered alone. Levels of postprandial plasma triglycerides declined with lactitol and PDX when administered with B. thetaiotaomicron. For intestinal hormone release, lactitol – alone or with B. thetaiotaomicron – increased the release of gastrointestinal peptide tyrosine tyrosine (PYY) as well as the area under the curve (AUC) measured for PYY (0–8 h). In addition, levels of insulin AUC (0–8 h) decreased in the lactitol and PDX-supplemented groups. Lactitol and PDX may both provide additional means to regulate postprandial metabolism and weight management, whereas the addition of B. thetaiotaomicron in the tested doses had only minor effects on the measured parameters.

Prebiotics Modulate the Effects of Antibiotics on Gut Microbial Diversity and Functioning in Vitro

Intestinal bacteria carry out many fundamental roles, such as the fermentation of non-digestible dietary carbohydrates to produce short chain fatty acids (SCFAs), which can affect host energy levels and gut hormone regulation. Understanding how to manage this ecosystem to improve human health is an important but challenging goal. Antibiotics are the front line of defence against pathogens, but in turn they have adverse effects on indigenous microbial diversity and function. Here, we have investigated whether dietary supplementation—another method used to modulate gut composition and function—could be used to ameliorate the side effects of antibiotics. We perturbed gut bacterial communities with gentamicin and ampicillin in anaerobic batch cultures in vitro. Cultures were supplemented with either pectin (a non-fermentable fibre), inulin (a commonly used prebiotic that promotes the growth of beneficial bacteria) or neither. Although antibiotics often negated the beneficial effects of dietary supplementation, in some treatment combinations, notably ampicillin and inulin, dietary supplementation ameliorated the effects of antibiotics. There is therefore potential for using supplements to lessen the adverse effects of antibiotics. Further knowledge of such mechanisms could lead to better therapeutic manipulation of the human gut microbiota.

The effects of symbiotic therapy on anthropometric measures, body composition and blood pressure in patient with metabolic syndrome: a triple blind RCT

BACKGROUND

Increase in prevalence of obesity and type 2 diabetes which are of the main risk factors of metabolic syndrome, is not only the result of changes in genetic, diet or physical activity, but also an imbalance of micro flora may play an important role. Therefore, alteration of micro flora using pre/probiotic is considered as a new strategy for treatment of metabolic disorders.

METHODS

The current study is a triple blind randomized controlled trial. 46 patients from both sexes, who fulfilled inclusion criteria, randomly categorized into intervention or placebo group. The intervention and placebo groups consumed 2 probiotic capsules or 2 placebo capsules during 3 months, respectively. Both groups received a weight loss diet, according to their adjusted ideal body weight. Anthropometric, body composition, blood pressure and nutritional measurements were done in the beginning, at 6th week, and at the end of the study. T-test and paired-t test were used for statistical analysis.

RESULTS

40 patients completed the study. BMI, WC, HC, fat mass, lean mass and blood pressure were reduced in all participants (p< 0.05). Systolic blood pressure in symbiotic group was less than placebo group, significantly (p< 0.05). The trend of weight loss in symbiotic group continued at least for 12 weeks while it was stopped at week 6 in placebo group.

CONCLUSION

Symbiotic supplement with the weight loss diet had synergistic effects on improvement in systolic blood pressure and anthropometric measurements. Based on our findings, symbiotic can postpone plateau phase of weight loss and it may prevent resistance to further weight loss.

Postprandial effects of polydextrose on satiety hormone responses and subjective feelings of appetite in obese participants

Background

Dietary fibers are associated with enhanced satiety. However, the mechanism of different dietary fibers contributing to satiety-related gastrointestinal (GI) peptide release, especially in an obese population, is still poorly understood. Polydextrose (PDX), a water-soluble glucose polymer, has demonstrated its ability to reduce energy intake at a subsequent meal, but its mechanism of action requires further research. Also, there is limited evidence on its capacity to regulate subjective feelings of appetite. This study examines the effects of PDX on postprandial secretion of satiety-related GI peptides, short chain fatty acids (SCFAs), lactic acid, and subjective appetite ratings in obese participants.

Methods

18 non-diabetic, obese participants (42.0 y, 33.6 kg/m²) consumed a high-fat meal (4293 kJ, 36% from fat) with or without PDX (15 g) in an acute, multicenter, randomized, double-blind, placebo-controlled and crossover trial. Postprandial plasma concentrations of satiety-related peptides, namely ghrelin, cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), and peptide YY (PYY), as well as SCFAs and lactic acid were assessed. GI peptide, SCFA and lactate concentrations were then modeled using a linear mixed-effects model.

The subjective feelings of hunger, satisfaction, and desire to eat were evaluated using visual analogue scales (VAS), which were analyzed as incremental areas under the curve (iAUC) during the satiation and satiety periods.

Results

We found that PDX supplementation increased plasma GLP-1 levels more than the placebo treatment (P = 0.02). In the whole group, GLP-1 concentrations found in participants older than 40 years old were significantly lower (P = 0.01) as compared to those aged 40 years or less. There were no statistically significant differences in postprandial ghrelin, CCK, or PYY responses. The lactic acid concentrations were significantly (P = 0.01) decreased in the PDX group, while no significant changes in SCFAs were found. PDX reduced iAUC for hunger by 40% (P = 0.03) and marginally increased satisfaction by 22.5% (P = 0.08) during the post-meal satiety period.

Conclusion

Polydextrose increased the postprandial secretion of the satiety hormone GLP-1 and reduced hunger after a high-fat meal. PDX also reduced the elevated postprandial lactic acid levels in plasma. Therefore, PDX may offer an additional means to regulate inter-meal satiety and improve postprandial metabolism in obese participants.

Microbiota regulation of the Mammalian gut-brain axis

The realization that the microbiota-gut-brain axis plays a critical role in health and disease has emerged over the past decade. The brain-gut axis is a bidirectional communication system between the central nervous system (CNS) and the gastrointestinal tract. Regulation of the microbiota-brain-gut axis is essential for maintaining homeostasis, including that of the CNS. The routes of this communication are not fully elucidated but include neural, humoral, immune, and metabolic pathways. A number of approaches have been used to interrogate this axis including the use of germ-free animals, probiotic agents, antibiotics, or animals exposed to pathogenic bacterial infections. Together, it is clear that the gut microbiota can be a key regulator of mood, cognition, pain, and obesity. Understanding microbiota-brain interactions is an exciting area of research which may contribute new insights into individual variations in cognition, personality, mood, sleep, and eating behavior, and how they contribute to a range of neuropsychiatric diseases ranging from affective disorders to autism and schizophrenia. Finally, the concept of psychobiotics, bacterial-based interventions with mental health benefit, is also emerging.

The impact of microbiota on brain and behavior: mechanisms & therapeutic potential

There is increasing evidence that host-microbe interactions play a key role in maintaining homeostasis. Alterations in gut microbial composition is associated with marked changes in behaviors relevant to mood, pain and cognition, establishing the critical importance of the bi-directional pathway of communication between the microbiota and the brain in health and disease. Dysfunction of the microbiome-brain-gut axis has been implicated in stress-related disorders such as depression, anxiety and irritable bowel syndrome and neurodevelopmental disorders such as autism. Bacterial colonization of the gut is central to postnatal development and maturation of key systems that have the capacity to influence central nervous system (CNS) programming and signaling, including the immune and endocrine systems. Moreover, there is now expanding evidence for the view that enteric microbiota plays a role in early programming and later response to acute and chronic stress. This view is supported by studies in germ-free mice and in animals exposed to pathogenic bacterial infections, probiotic agents or antibiotics. Although communication between gut microbiota and the CNS are not fully elucidated, neural, hormonal, immune and metabolic pathways have been suggested. Thus, the concept of a microbiome-brain-gut axis is emerging, suggesting microbiota-modulating strategies may be a tractable therapeutic approach for developing novel treatments for CNS disorders.

The effects of gut microbiota on CNS function in humans

The role of the gastrointestinal microbiota in human brain development and function is an area of increasing interest and research. Preclinical models suggest a role for the microbiota in broad aspects of human health, including mood, cognition, and chronic pain. Early human studies suggest that altering the microbiota with beneficial bacteria, or probiotics, can lead to changes in brain function, as well as subjective reports of mood. As the mechanisms of bidirectional communication between the brain and microbiota are better understood, it is expected that these pathways will be harnessed to provide novel methods to enhance health and treat disease.

Combined effects of oligofructose and Bifidobacterium animalis on gut microbiota and glycemia in obese rats

OBJECTIVE

Prebiotics and probiotics may be able to modify an obesity-associated gut microbiota. The aim of this study was to examine the individual and combined effects of the prebiotic oligofructose (OFS) and the probiotic Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on gut microbiota and host metabolism in obese rats.

METHODS

Adult male, diet-induced obese Sprague Dawley rats were randomized to: (1) Control (C); (2) 10% OFS; (3) BB-12; (4) OFS + BB-12 for 8 weeks (n = 9-10 rats/group). Body composition, glycemia, gut permeability, satiety hormones, cytokines, and gut microbiota were examined.

RESULTS

Prebiotic, but not probiotic reduced energy intake, weight gain, and fat mass (P < 0.01). OFS, BB-12, and the combined OFS + BB-12 improved glycemia (P < 0.05). Individually, OFS and BB-12 reduced insulin levels (P < 0.05). Portal GLP-1 was increased with OFS, whereas probiotic increased GLP-2 (P < 0.05). There was a marked increase in bifidobacteria and lactobacilli (P < 0.01) with OFS that was not observed with probiotic alone.

CONCLUSIONS

The impact of prebiotic intake on body composition and gut microbiota was of greater magnitude than the probiotic BB-12. Despite this, an improvement in glucose AUC with both prebiotic or probiotic demonstrates the beneficial role of each of these "biotic" agents in glycemic control.

Neuroimaging the microbiome-gut-brain axis

The brain is the most complex organ in the human body, interacting with every other major organ system to continuously maintain homeostasis. Thus it is not surprising that the brain also interacts with our microbiota, the trillions of bacteria and other organisms inhabiting the ecosystem of the human being. As we gather knowledge about the way that our microbiota interact with their local environments, there is also increasing interest in their communication with the brain.

The effect of dietary prebiotics and probiotics on body weight, large intestine indices, and fecal bile acid profile in wild type and IL10-/- mice

Previous studies have suggested roles of probiotics and prebiotics on body weight management and intestinal function. Here, the effects of a dietary prebiotic, inulin (50 mg/g diet), and probiotic, Bfidobacterium animalis subsp. lactis (Bb12) (final dose verified at 10⁵ colony forming unit (cfu)/g diet, comparable to human consumption), were determined separately and in combination in mice using cellulose-based AIN-93G diets under conditions allowed for the growth of commensal bacteria. Continuous consumption of Bb12 and/or inulin did not affect food intake or body, liver, and spleen weights of young and adult mice. Fecal bile acid profiles were determined by nanoESI-MS/MS tandem mass spectrometry. In the presence of inulin, more bacterial deconjugation of taurine from primary bile acids was observed along with an increased cecal weight. Consumption of inulin in the absence or presence of Bb12 also increased the villus cell height in the proximal colon along with a trend of higher bile acid sulfation by intestinal cells. Feeding Bb12 alone at the physiological dose did not affect bile acid deconjugation and had little effect on other intestinal indices. Although interleukin (IL)10-null mice are susceptible to enterocolitis, they maintained the same body weight as the wild type mice under our specific pathogen-free housing condition and showed no signs of inflammation. Nevertheless, they had smaller cecum suggesting a mildly compromised intestinal development even before the disease manifestation. Our results are consistent with the notion that dietary factors such as prebiotics play important roles in the growth of intestinal microbiota and may impact on the intestinal health. In addition, fecal bile acid profiling could potentially be a non-invasive tool in monitoring the intestinal environment.

Voices from within: gut microbes and the CNS

Recent advances in research have greatly increased our understanding of the importance of the gut microbiota. Bacterial colonization of the intestine is critical to the normal development of many aspects of physiology such as the immune and endocrine systems. It is emerging that the influence of the gut microbiota also extends to modulation of host neural development. Furthermore, the overall balance in composition of the microbiota, together with the influence of pivotal species that induce specific responses, can modulate adult neural function, peripherally and centrally. Effects of commensal gut bacteria in adult animals include protection from the central effects of infection and inflammation as well as modulation of normal behavioral responses. There is now robust evidence that gut bacteria influence the enteric nervous system, an effect that may contribute to afferent signaling to the brain. The vagus nerve has also emerged as an important means of communicating signals from gut bacteria to the CNS. Further understanding of the mechanisms underlying microbiome-gut-brain communication will provide us with new insight into the symbiotic relationship between gut microbiota and their mammalian hosts and help us identify the potential for microbial-based therapeutic strategies to aid in the treatment of mood disorders.

Can antibiotic treatment in preweaning rats alter body composition in adulthood?

BACKGROUND

It is suggested that antibiotherapy in infancy might program adult body composition and thus could be a determinant of obesity risk. Although not convincingly substantiated by existing literature, this assumption is plausible since antibiotics affect intestinal microbiota, whose composition in adulthood is potentially programmable during infancy and which is able to interact with both fat development and central control of appetite.

OBJECTIVES

In order to substantiate the link between antibiotherapy and programming of adult body composition, the present study investigated the impact of a course of amoxicillin treatment in neonatal period on subsequent growth and body composition in rats.

METHODS

Suckling rat pups were treated by oral gavage with an amoxicillin solution (150 mg·kg(-1)) or vehicle from postnatal day (PND)5 to PND15. All animals were fully weaned at PND21 then fed a standard diet until PND130. Animal growth and food intake were followed up until PND130, when body composition and plasma leptin were measured. Faecal microbiota was typified at regular intervals using real-time quantitative polymerase chain reaction.

RESULTS

Preweaning amoxicillin treatment affected the composition of the faecal microbiota of pups at PND21 but this impact did not sustain long beyond the antibiotic supplementation. Immediately after weaning, a transient increase in food intake (+11%) was noticed in amoxicillin-treated animals. However, no significant impact on either growth or body composition at adulthood was observed.

CONCLUSIONS

In a neonatal animal model there is no evidence of a programming of adult body weight and composition by wide-spectrum antibiotic treatment in early life.

Effect ofLactobacillus acidophilusNCDC 13 supplementation on the progression of obesity in diet-induced obese mice

There is an increased interest in investigating the relationship between the gut microbiota and energy homeostasis. Probiotics are health beneficial microbes mainly categorised under the genusLactobacillusandBifidobacterium, which when administered in adequate amounts confer health benefits to the host, and have been implicated in various physiological functions. The potential role of probiotics in energy homeostasis is a current and an emerging area of research. In the present study,Lactobacillus acidophilusNCDC 13 was used to evaluate its anti-obesity potential in diet-induced obese (C57BL/6) mice. The probiotic bacterial culture was administered in Indian yogurt preparation called ‘dahi’, prepared using native starter cultures, and compared with control dahi containing only dahi starter cultures. The dietary intervention was followed for 8 weeks, and whole-body fat composition, and liver and muscle adiposity were measured using MRI. Changes in gut microbiota were assessed by fluorescentin situhybridisation in faeces and caecal contents. The feeding of the probiotic brought no changes in body-weight gain, food and dahi intake when compared with the control dahi-fed animals. No significant changes in body fat composition, liver and muscle adiposity were also observed. At the end of the dietary intervention, a significant increase (P < 0·05) in the number of totalBifidobacteriumwas observed in both faeces and caecal contents of mice as a result of probiotic dahi administration. Thus,L. acidophilusNCDC 13 supplementation could be beneficial in shifting the gut microbiota balance positively. However, its anti-obesity potential could not be established in the present study and warrants further exploration.

Safety and intestinal microbiota modulation by the exopolysaccharide-producing strains Bifidobacterium animalis IPLA R1 and Bifidobacterium longum IPLA E44 orally administered to Wistar rats

Bifidobacterium animalis subsp. lactis IPLA R1 and Bifidobacterium longum IPLA E44 strains were tested for their safety and ability to modulate the intestinal microbiota in vivo. Chemically simulated gastrointestinal digestion showed considerably lower survival of E44 than R1 strain, the first microorganism also being more sensitive to refrigerated storage in 10% skimmed milk at 4°C. Harmful glycosidic activities were absent, or at low levels, in the strains R1 and E44. Both strains were sensitive to most antibiotics and resistant to aminoglycosides, a common feature in bifidobacteria. Similar to several other bifidobacteria strains, B. animalis subsp. lactis IPLA R1 displayed a moderate resistance against tetracycline which correlated with the presence of tet(W) gene in its genome. The general parameters indicating well-being status, as well as translocation to different organs and histological examination of the gut tissues, revealed no changes induced by the administration of bifidobacteria to rats. Twelve-week-old male Wistar rats were distributed into three groups, eight rats in each. Two groups were administered daily over 10⁸cfu of the corresponding strain suspended in 10% skimmed milk for 24 days, whereas rats in the placebo group received skimmed milk without microorganisms added. The microbiota and short chain fatty acids (SCFA) were monitored in faeces at different time points during treatment and in caecum content at the end of the assay. Quantitative PCR (qPCR) showed that faecal and caecal Bifidobacterium levels were higher in bifidobacteria-fed rats than in the placebo rats at the end of the intervention, whereas total anaerobic plate counts did not show significant differences. Quantification of B. animalis and B. longum by qPCR showed that, independent of the microorganism administered, treatment with bifidobacteria resulted in higher levels of B. animalis in the caecum. PCR-DGGE analysis of microbial populations revealed a higher diversity of bands in caecum content of rats fed B. animalis IPLA R1 than in the placebo group and rats fed B. longum IPLA E44. Remarkably, although no variations in the proportion of acetate, propionate and butyrate were found, at the end of the assay the total SCFA concentration in the faeces of rats fed bifidobacteria was significantly higher and those in caecum content significantly lower, than that of the placebo group. This suggests a displacement of the SCFA production to parts of the colon beyond the caecum in rats receiving bifidobacteria. Therefore, the oral administration of B. animalis IPLA R1 and B. longum E44 can be considered safe, these microorganisms having the ability to modulate the intestinal microbiota of rats by influencing SCFA and the bifidobacterial population levels.

Changes in calcium status in aged rats fed Lactobacillus GG and Bifidobacterium lactis and oligofructose-enriched inulin

In this study we hypothesized that an increase in numbers of beneficial bacteria in the large intestine can affect calcium (Ca) status in the elderly. Adult and aged rats were fed a diet with or without synbiotics for 21 days. Synbiotics increased the numbers of lactobacilli and bifidobacteria in large intestine in both adult and aged rats. The plasma Ca concentration was significantly increased while osteocalcin concentration was significantly decreased only in aged rats fed synbiotics.

Modulation of granulocyte functions by peptide YY in the rat: age-related differences in Y receptors expression and plasma dipeptidyl peptidase 4 activity

It has been acknowledged that aging exerts detrimental effects on cells of the innate immune system and that neuropeptides, including neuropeptide Y (NPY) and NPY-related peptides fine-tune the activity of these cells through a receptor specific mechanism. The present study investigated the age-dependent potential of peptide YY (PYY) to modulate different granulocyte functions. The PYY reduced the carrageenan-elicited granulocyte accumulation into the air-pouch of aged (24 months) rats, and markedly decreased the phagocytosis of zymosan, as well as the H(2)O(2) production, when applied in vivo (20 microg/air-pouch). The anti-inflammatory effect of PYY was less prominent in adult (8 months) and young (3 months) rats. However, the proportions of granulocytes expressing Y1, Y2 and Y5 receptor subtypes were significantly lower in both aged and young rats when compared to adult rats. Furthermore, the aging was found to be associated with the diminished dipeptidyl peptidase 4 (DP4, an enzyme converting the NPY and PYY to Y2/Y5 receptor selective agonists) activity in plasma. In conclusion, the diverse age-related anti-inflammatory effect of PYY in rats originates from different expression levels of Y1, Y2, and Y5 receptor subtypes in addition to different plasma DP4 activity.

Top-down systems biology modeling of host metabotype-microbiome associations in obese rodents

Covariation in the structural composition of the gut microbiome and the spectroscopically derived metabolic phenotype (metabotype) of a rodent model for obesity were investigated using a range of multivariate statistical tools. Urine and plasma samples from three strains of 10-week-old male Zucker rats (obese (fa/fa, n=8), lean (fa/-, n=8) and lean (-/-, n=8)) were characterized via high-resolution 1H NMR spectroscopy, and in parallel, the fecal microbial composition was investigated using fluorescence in situ hydridization (FISH) and denaturing gradient gel electrophoresis (DGGE) methods. All three Zucker strains had different relative abundances of the dominant members of their intestinal microbiota (FISH), with the novel observation of a Halomonas and a Sphingomonas species being present in the (fa/fa) obese strain on the basis of DGGE data. The two functionally and phenotypically normal Zucker strains (fa/- and -/-) were readily distinguished from the (fa/fa) obese rats on the basis of their metabotypes with relatively lower urinary hippurate and creatinine, relatively higher levels of urinary isoleucine, leucine and acetate and higher plasma LDL and VLDL levels typifying the (fa/fa) obese strain. Collectively, these data suggest a conditional host genetic involvement in selection of the microbial species in each host strain, and that both lean and obese animals could have specific metabolic phenotypes that are linked to their individual microbiomes.

Intestinal microflora and metabolic diseases

Recent advances in molecular sequencing technology have allowed researchers to answer major questions regarding the relationship between a vast genomic diversity-such as found in the intestinal microflora-and host physiology. Over the past few years, it has been established that, in obesity, type 1 diabetes and Crohn's disease-to cite but a few-the intestinal microflora play a pathophysiological role and can induce, transfer or prevent the outcome of such conditions. A few of the molecular vectors responsible for this regulatory role have been determined. Some are related to control of the immune, vascular, endocrine and nervous systems located in the intestines. However, more important is the fact that the intestinal microflora-to-host relationship is bidirectional, with evidence of an impact of the host genome on the intestinal microbiome. This means that the ecology shared by the host and gut microflora should now be considered a new player that can be manipulated, using pharmacological and nutritional approaches, to control physiological functions and pathological outcomes. What now remains is to demonstrate the molecular connection between the intestinal microflora and metabolic diseases. We propose here that the proinflammatory lipopolysaccharides play a causal role in the onset of metabolic disorders.

Developmental changes of gut microflora and enzyme activity in rat pups exposed to fat-rich diet

The aim of this study was to investigate the effect of a high-fat (HF)/energy diet on the intestinal microbiota, the alkaline phosphatase (AP) activity, and related parameters of growth and obesity during the suckling and weaning periods in male Sprague-Dawley rats. From birth, nutrition in suckling pups was manipulated by feeding rat dams either HF or a standard diet, and then after weaning, by exposure of experimental pups to the HF, and control rats to normal diet. On days 15, 20, 40 the numbers of 2 microbial groups, i.e., Bacteroides/Prevotella (BAC) and the Lactobacillus/Enterococcus (LAB) in the jejunum, were determined by fluorescent in situ hybridization technique, and the AP activity was assayed histochemically. During all investigated periods HF pups gained body fat more rapidly than control animals, but from weaning they displayed significantly stunted growth resulting in final body weight loss. Obesity in HF rats was also accompanied by higher LAB and lower numbers of BAC and with permanently higher AP activity. Correlation of these data showed significant negative correlation between LAB, AP, and weight gain and energy efficiency, and significant positive correlation of BAC and AP activity with body fat. These data support the concept that postnatal nutritional experience represents an important factor affecting the ontogeny of intestinal microbial communities and intestinal function. These acquired changes could be a component of regulatory mechanisms involved in adverse and/or positive consequences of HF diet for adiposity, body weight, and energy-balance control in later life.