The significance of insecure attachment and disorganization in the development of children's externalizing behavior: A meta-analytic study

This study addresses the extent to which insecure and disorganized attachments increase risk for externalizing problems using meta-analysis. From 69 samples (N = 5,947), the association between insecurity and externalizing problems was significant, d = 0.31 (95% CI: 0.23, 0.40). Larger effects were found for boys (d = 0.35), clinical samples (d = 0.49), and from observation-based outcome assessments (d = 0.58). Larger effects were found for attachment assessments other than the Strange Situation. Overall, disorganized children appeared at elevated risk (d = 0.34, 95% CI: 0.18, 0.50), with weaker effects for avoidance (d = 0.12, 95% CI: 0.03, 0.21) and resistance (d = 0.11, 95% CI: −0.04, 0.26). The results are discussed in terms of the potential significance of attachment for mental health.

Prebiotic effect of fruit and vegetable shots containing Jerusalem artichoke inulin : a human intervention study

The present study aimed to determine the prebiotic effect of fruit and vegetable shots containing inulin derived from Jerusalem artichoke (JA). A three-arm parallel, placebo-controlled, double-blind study was carried out with sixty-six healthy human volunteers (thirty-three men and thirty-three women, age range: 18–50 years). Subjects were randomised into three groups (n 22) assigned to consume either the test shots, pear-carrot-sea buckthorn (PCS) or plum-pear-beetroot (PPB), containing JA inulin (5 g/d) or the placebo. Fluorescent in situ hybridisation was used to monitor populations of total bacteria, bacteroides, bifidobacteria, Clostridium perfringens/histolyticum subgroup, Eubacterium rectale/Clostridium coccoides group, Lactobacillus/Enterococcus spp., Atopobium spp., Faecalibacterium prausnitzii and propionibacteria. Bifidobacteria levels were significantly higher on consumption of both the PCS and PPB shots (10·0 (sd 0·24) and 9·8 (sd 0·22) log10 cells/g faeces, respectively) compared with placebo (9·3 (sd 0·42) log10 cells/g faeces) (P < 0·0001). A small though significant increase in Lactobacillus/Enterococcus group was also observed for both the PCS and PPB shots (8·3 (sd 0·49) and 8·3 (sd 0·36) log10 cells/g faeces, respectively) compared with placebo (8·1 (sd 0·37) log10 cells/g faeces) (P = 0·042). Other bacterial groups and faecal SCFA concentrations remained unaffected. No extremities were seen in the adverse events, medication or bowel habits. A slight significant increase in flatulence was reported in the subjects consuming the PCS and PPB shots compared with placebo, but overall flatulence levels remained mild. A very high level of compliance (>90 %) to the product was observed. The present study confirms the prebiotic efficacy of fruit and vegetable shots containing JA inulin.

The influence of pomegranate by-product and punicalagins on selected groups of human intestinal microbiota.

We have examined the gut bacterial metabolism of pomegranate by-product (POMx) and major pomegranate polyphenols, punicalagins, using pH-controlled, stirred, batch culture fermentation systems reflective of the distal region of the human large intestine. Incubation of POMx or punicalagins with faecal bacteria resulted in formation of the dibenzopyranone-type urolithins. The time course profile confirmed the tetrahydroxylated urolithin D as the first product of microbial transformation, followed by compounds with decreasing number of phenolic hydroxy groups: the trihydroxy analogue urolithin C and dihydroxylated urolithin A. POMx exposure enhanced the growth of total bacteria, Bifidobacterium spp. and Lactobacillus spp., without influencing the Clostridium coccoides–Eubacterium rectale group and the C. histolyticum group. In addition, POMx increased concentrations of short chain fatty acids (SCFA) viz. acetate, propionate and butyrate in the fermentation medium. Punicalagins did not affect the growth of bacteria or production of SCFA. The results suggest that POMx oligomers, composed of gallic acid, ellagic acid and glucose units, may account for the enhanced growth of probiotic bacteria.

A double-blind, placebo-controlled, cross-over study to establish the bifidogenic effect of a very-long-chain inulin extracted from globe artichoke (Cynara scolymus) in healthy human subjects

There is growing interest in the use of inulins as substrates for the selective growth of beneficial gut bacteria such as bifidobacteria and lactobacilli because recent studies have established that their prebiotic effect is linked to several health benefits. In the present study, the impact of a very-long-chain inulin (VLCI), derived from globe artichoke (Cynara scolymus), on the human intestinal microbiota compared with maltodextrin was determined. A double-blind, cross-over study was carried out in thirty-two healthy adults who were randomised into two groups and consumed 10 g/d of either VLCI or maltodextrin, for two 3-week study periods, separated by a 3-week washout period. Numbers of faecal bifidobacteria and lactobacilli were significantly higher upon VLCI ingestion compared with the placebo. Additionally, levels of Atopobium group significantly increased, while Bacteroides–Prevotella numbers were significantly reduced. No significant changes in faecal SCFA concentrations were observed. There were no adverse gastrointestinal symptoms apart from a significant increase in mild and moderate bloating upon VLCI ingestion. These observations were also confirmed by in vitro gas production measurements. In conclusion, daily consumption of VLCI extracted from globe artichoke exerted a pronounced prebiotic effect on the human faecal microbiota composition and was well tolerated by all volunteers.

Response of porcine intestinal in vitro organ culture tissues following exposure to Lactobacillus plantarum JC1 and Salmonella Typhimurium SL1344.

The development of novel intervention strategies for the control of zoonoses caused by bacteria such as Salmonella spp. in livestock requires appropriate experimental models to assess their suitability. Here, a novel porcine intestinal in vitro organ culture (IVOC) model utilizing cell crown (CC) technology (CCIVOC) (Scaffdex) was developed. The CCIVOC model was employed to investigate the characteristics of association of S. enterica serovar Typhimurium strain SL1344 with porcine intestinal tissue following exposure to a Lactobacillus plantarum strain. The association of bacteria to host cells was examined by light microscopy and electron microscopy (EM) after appropriate treatments and staining, while changes in the proteome of porcine jejunal tissues were investigated using quantitative label-free proteomics. Exposure of porcine intestinal mucosal tissues to L. plantarum JC1 did not reduce the numbers of S. Typhimurium bacteria associating to the tissues but was associated with significant (P < 0.005) reductions in the percentages of areas of intestinal IVOC tissues giving positive staining results for acidic mucins. Conversely, the quantity of neutrally charged mucins present within the goblet cells of the IVOC tissues increased significantly (P < 0.05). In addition, tubulin- was expressed at high levels following inoculation of jejunal IVOC tissues with L. plantarum. Although L. plantarum JC1 did not reduce the association of S. Typhimurium strain SL1344 to the jejunal IVOC tissues, detection of increased acidic mucin secretion, host cytoskeletal rearrangements, and proteins involved in the porcine immune response demonstrated that this strain of L. plantarum may contribute to protecting the pig from infections by S. Typhimurium or other pathogens.

Bacterial, SCFA and gas profiles of a range of food ingredients following in vitro fermentation by human colonic microbiota.

It is now apparent that there is a strong link between health and nutrition and this can be seen clearly when we talk of obesity. The food industry is trying to capitalise on this by adapting high sugar/fat foods to become healthier alternatives. In confectionery food ingredients can be used for a range of purposes including sucrose replacement. Many of these ingredients may also evade digestion in the upper gut and be fermented by the gut microbiota upon entering the colon. This study was designed to screen a range of ingredients and their activities on the gut microbiota. In this study we screened a range of these ingredients in triplicate batch culture fermentations with known prebiotics as controls. Changes in bacteriology were monitored using FISH. SCFA were measured by GC and gas production was assessed during anaerobic batch fermentations. Bacterial enumeration showed significant increases (P ≤ 0.05) in bifidobacteria and lactobacilli with polydextrose and most polyols with no significant increases in Clostridium histolyticum/perfringens. SCFA and gas formation indicated that the substrates added to the fermenters were being utilised by the gut microbiota. It therefore appears these ingredients exert some prebiotic activity in vitro. Further studies, particularly in human volunteers, are necessary.

A human volunteer study to assess the impact of confectionery sweeteners on the gut microbiota composition.

Sweeteners are being sourced to lower the energetic value of confectionery including chocolates. Some, especially non-digestible carbohydrates, may possess other benefits for human health upon their fermentation by the colonic microbiota. The present study assessed non-digestible carbohydrate sweeteners, selected for use in low-energy chocolates, for their ability to beneficially modulate faecal bacterial profiles in human volunteers. Forty volunteers consumed a test chocolate (low-energy or experimental chocolate) containing 22·8 g of maltitol (MTL), MTL and polydextrose (PDX), or MTL and resistant starch for fourteen consecutive days. The dose of the test chocolates was doubled every 2 weeks over a 6-week period. Numbers of faecal bifidobacteria significantly increased with all the three test treatments. Chocolate containing the PDX blend also significantly increased faecal lactobacilli (P = 0·00 001) after the 6 weeks. The PDX blend also showed significant increases in faecal propionate and butyrate (P = 0·002 and 0·006, respectively). All the test chocolates were well tolerated with no significant change in bowel habit or intestinal symptoms even at a daily dose of 45·6 g of non-digestible carbohydrate sweetener. This is of importance not only for giving manufacturers a sugar replacement that can reduce energetic content, but also for providing a well-tolerated means of delivering high levels of non-digestible carbohydrates into the colon, bringing about improvements in the biomarkers of gut health.

Rifaximin modulates the colonic microbiota of patients with Crohn's disease: an in vitro approach using a continuous culture colonic model system.

Rifaximin, a rifamycin derivative, has been reported to induce clinical remission of active Crohn's disease (CD), a chronic inflammatory bowel disorder. In order to understand how rifaximin affects the colonic microbiota and its metabolism, an in vitro human colonic model system was used in this study. We investigated the impact of the administration of 1800 mg/day of rifaximin on the faecal microbiota of four patients affected by colonic active CD [Crohn's disease activity index (CDAI > 200)] using a continuous culture colonic model system. We studied the effect of rifaximin on the human gut microbiota using fluorescence in situ hybridization, quantitative PCR and PCR–denaturing gradient gel electrophoresis. Furthermore, we investigated the effect of the antibiotic on microbial metabolic profiles, using 1H-NMR and solid phase microextraction coupled with gas chromatography/mass spectrometry, and its potential genotoxicity and cytotoxicity, using Comet and growth curve assays. Rifaximin did not affect the overall composition of the gut microbiota, whereas it caused an increase in concentration of Bifidobacterium, Atopobium and Faecalibacterium prausnitzii. A shift in microbial metabolism was observed, as shown by increases in short-chain fatty acids, propanol, decanol, nonanone and aromatic organic compounds, and decreases in ethanol, methanol and glutamate. No genotoxicity or cytotoxicity was attributed to rifaximin, and conversely rifaximin was shown to have a chemopreventive role by protecting against hydrogen peroxide-induced DNA damage. We demonstrated that rifaximin, while not altering the overall structure of the human colonic microbiota, increased bifidobacteria and led to variation of metabolic profiles associated with potential beneficial effects on the host.

Effect of molecule branching and glycosidic linkage on the degradation of polydextrose by gut microbiota.

Polydextrose is a randomly linked complex glucose oligomer that is widely used as a sugar replacer, bulking agent, dietary fiber and prebiotic. Polydextrose is poorly utilized by the host and, during gastrointestinal transit, it is slowly degraded by intestinal microbes, although it is not known which parts of the complex molecule are preferred by the microbes. The microbial degradation of polydextrose was assessed by using a simulated model of colonic fermentation. The degradation products and their glycosidic linkages were measured by combined gas chromatography and mass spectrometry, and compared to those of intact polydextrose. Fermentation resulted in an increase in the relative abundance of non-branched molecules with a concomitant decrease in single-branched glucose molecules and a reduced total number of branching points. A detailed analysis showed a preponderance of 1,6 pyranose linkages. The results of this study demonstrate how intestinal microbes selectively degrade polydextrose, and provide an insight into the preferences of gut microbiota in the presence of different glycosidic linkages.

Dietary prebiotics: current status and new definition

In November 2008, a group of scientists met at the 6th Meeting of the International Scientific Association of Probiotics and Prebiotics (ISAPP) in London, Ontario, Canada, to discuss the functionality of prebiotics. As a result of this, it was concluded that the prebiotic field is currently dominated by gastrointestinal events. However, in the future, it may be the case that other mixed microbial ecosystems may be modulated by a prebiotic approach, such as the oral cavity, skin and the urogenital tract. Therefore, a decision was taken to build upon the current prebiotic status and define a niche for ‘dietary prebiotics’. This review is co-authored by the working group of ISAPP scientists and sets the background for defining a dietary prebiotic as ‘‘a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health’’.