The fruit of the date palm (Phoenix dactylifera L.) is a rich source of dietary fibre and polyphenols. We have investigated gut bacterial changes induced by the whole date fruit extract (digested date extract; DDE) and its polyphenol-rich extract (date polyphenol extract; DPE) using faecal, pH-controlled, mixed batch cultures mimicking the distal part of the human large intestine, and utilising an array of microbial group-specific 16S rRNA oligonucleotide probes. Fluorescence microscopic enumeration indicated that there was a significant increase in the growth of bifidobacteria in response to both treatments, whilst whole dates also increased bacteroides at 24 h and the total bacterial counts at later fermentation time points when compared with DPE alone. Bacterial metabolism of whole date fruit led to the production of SCFA, with acetate significantly increasing following bacterial incubation with DDE. In addition, the production of flavonoid aglycones (myricetin, luteolin, quercetin and apigenin) and the anthocyanidin petunidin in less than 1 h was also observed. Lastly, the potential of DDE, DPE and metabolites to inhibit Caco-2 cell growth was investigated, indicating that both were capable of potentially acting as antiproliferative agents in vitro, following a 48 h exposure. This potential to inhibit growth was reduced following fermentation. Together these data suggest that consumption of date fruits may enhance colon health by increasing beneficial bacterial growth and inhibiting the proliferation of colon cancer cells. This is an early suggestion that date intake by humans may aid in the maintenance of bowel health and even the reduction of colorectal cancer development.

BackgroundAgeing increases risk of respiratory infections and impairs the response to influenza vaccination. Pre- and probiotics offer an opportunity to modulate anti-viral defenses and the response to vaccination via alteration of the gut microbiota. This study investigated the effect of a novel probiotic, Bifidobacterium longum bv. infantis CCUG 52,486, combined with a prebiotic, gluco-oligosaccharide (B. longum + Gl-OS), on the response to seasonal influenza vaccination in young and older subjects in a double-blind, randomized controlled trial, taking into account the influence of immunosenescence markers at baseline.ResultsVaccination resulted in a significant increase in total antibody titres, vaccine-specific IgA, IgM and IgG and seroprotection to all three subunits of the vaccine in both young and older subjects, and in general, the increases in young subjects were greater. There was little effect of the synbiotic, although it tended to reduce seroconversion to the Brisbane subunit of the vaccine and the vaccine-specific IgG response in older subjects. Immunological characterization revealed that older subjects randomized to the synbiotic had a significantly higher number of senescent (CD28−CD57+) helper T cells at baseline compared with those randomized to the placebo, and they also had significantly higher plasma levels of anti-CMV IgG and a greater tendency for CMV seropositivity. Moreover, higher numbers of CD28−CD57+ helper T cells were associated with failure to seroconvert to Brisbane, strongly suggesting that the subjects randomized to the synbiotic were already at a significant disadvantage in terms of likely ability to respond to the vaccine compared with those randomized to the placebo.ConclusionsAgeing was associated with marked impairment of the antibody response to influenza vaccination in older subjects and the synbiotic failed to reverse this impairment. However, the older subjects randomized to the synbiotic were at a significant disadvantage due to a greater degree of immunosenscence at baseline compared with those randomized to the placebo. Thus, baseline differences in immunosenescence between the randomized groups are likely to have influenced the outcome of the intervention, highlighting the need for detailed immunological characterization of subjects prior to interventions.Trial registrationClinicaltrials.gov NCT01066377.Electronic supplementary materialThe online version of this article (doi:10.1186/s12979-016-0061-4) contains supplementary material, which is available to authorized users.

SummaryBackground & aimsAgeing increases risk of respiratory infections and impairs the response to influenza vaccination. Pre- and pro-biotics offer an opportunity to modulate anti-viral defenses and the response to vaccination via alteration of the gut microbiota. This study investigated the effect of a novel probiotic, Bifidobacterium longum bv. infantis CCUG 52486, combined with a prebiotic, gluco-oligosaccharide, on the B and T cell response to seasonal influenza vaccination in young and older subjects .MethodsIn a double-blind, randomized controlled trial, 58 young (18–35 y) and 54 older (60–85 y) subjects were supplemented with the synbiotic for 8 weeks. At 4 weeks they were administered with a seasonal influenza vaccine. B and T cell phenotype and responsiveness to in vitro re-stimulation with the vaccine were assessed at baseline, 4, 6 and 8 weeks.ResultsB and T cell profiles differed markedly between young and older subjects. Vaccination increased numbers of memory, IgA+ memory, IgG+ memory and total IgG+ B cells in young subjects, but failed to do so in older subjects and did not significantly alter T cell subsets. Seroconversion to the H1N1 subunit in the older subjects was associated with higher post-vaccination numbers of plasma B cells, but seroconversion was less consistently associated with T cell phenotype. B and T cell subsets from both young and older subjects demonstrated a strong antigen-specific recall challenge, and although not influenced by age, responsiveness to the recall challenge was associated with seroconversion. In older subjects, CMV seropositivity was associated with a significantly lower recall response to the vaccine, but the synbiotic did not affect the responsiveness of B or T cells to re-stimulation with influenza vaccine.ConclusionsAntigen-specific B and T cell activation following an in vitro recall challenge with the influenza vaccine was influenced by CMV seropositivity, but not by a synbiotic.Registered under ClinicalTrials.gov Identifier no. NCT01066377.

Diet and other lifestyle habits have been reported to contribute to the development of dyslipidemia in various populations. Therefore, this study investigated the association between dyslipidemia and dietary and other lifestyle practices among Saudi adults. Data were collected from adults (≥20 years) not previously diagnosed with diabetes in a cross-sectional design. Demographic, anthropometric, and clinical characteristics, as well as lifestyle and dietary habits were recorded using a predesigned questionnaire. Fasting blood samples were drawn to estimate the serum lipid profile. Out of 1385 people, 858 (62%) (491 men, 367 women) had dyslipidemia. After regression analysis to adjust for age, body mass index, and waist circumference, an intake of ≥5 cups/week of Turkish coffee, or carbonated drinks was associated with increased risk of dyslipidemia in men (OR (95% CI), 2.74 (1.53, 4.89) p = 0.001, and 1.53 (1.04, 2.26) p = 0.03 respectively), while the same intake of American coffee had a protective effect (0.53 (0.30, 0.92) p = 0.025). Sleep duration <6 h, and smoking were also associated with increased risk in men (1.573 (1.14, 2.18) p = 0.006, and 1.41 (1.00, 1.99) p = 0.043 respectively). In women, an increased intake of fresh vegetables was associated with increased risk (2.07 (1.09, 3.94) p = 0.026), which could be attributed to added salad dressing. Thus, there are sex differences in response to dietary and lifestyle practices.

Objective: Study the association of dietary habits and other indicators of lifestyle with dysglycemia in Saudi adults. Methods: In a cross-sectional design, data were obtained from 1403 Saudi adults (⩾20 years), not previously diagnosed with diabetes. Demographics, lifestyle variables and dietary habits were obtained using a predesigned questionnaire. Fasting plasma glucose, glycated hemoglobin and 1-hour oral glucose tolerance test were used to identify dysglycemia. Regression analysis was performed to determine the associations of dietary factors and other indicators of lifestyle with dysglycemia. Results: A total 1075 adults (596 men, and 479 women) had normoglycemia, and 328 (195 men, and 133 women) had dysglycemia. Following adjustment for age, BMI and waist circumference, in men the weekly intake of 5 portions or more of red meat and Turkish coffee were associated with decreased odds of having dysglycemia odds ratio (OR) 0.444 (95% CI: 0.223, 0.881; P = .02) and 0.387 (95% CI: 0.202, 0.74; P = .004), respectively. In women, the intake of fresh juice 1 to 4 portions per week and 5 portions or more were associated with OR 0.603 (95% CI: 0.369, 0.985; P = .043) and OR 0.511 (95% CI: 0.279, 0.935; P = .029) decreased odds of having dysglycemia, respectively compared with women who did not drink fresh juice. The intake of 5 times or more per week of hibiscus drink was associated with increased odds of having dysglycemia, OR 5.551 (95% CI: 1.576, 19.55, P = .008) compared with women not using such a drink. Other lifestyle factors were not associated with dysglycemia. Conclusion: Dietary practices by studied Saudis have some impact on risk of dysglycemia, with obvious sex differences.