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Aging is associated with a decline in many components of the immune system (immunosenescence). Probiotics may improve the immune response in older people. The objective was to determine the effect of the combination of two probiotic organisms [ Lacticaseibacillus (previously known as Lactobacillus) rhamnosus GG (LGG) and Bifidobacterium animalis subsp. lactis , BB-12 (BB-12)] on a range of immune biomarkers measured in the blood of older people resident in care homes in the UK. In a randomized controlled trial, older people [aged 67–97 (mean 86) years] resident in care homes received the combination of LGG+BB-12 (1.3–1.6 × 109 CFU per day) or placebo for up to 12 months. Full blood count, blood immune cell phenotypes, plasma immune mediator concentrations, phagocytosis, and blood culture responses to immune stimulation were all measured. Response to seasonal influenza vaccination was measured in a subset of participants. Paired samples (i.e., before and after intervention) were available for 30 participants per group. LGG and BB-12 were more likely to be present in feces in the probiotic group and were present at higher numbers. There was no significant effect of the probiotics on components of the full blood count, blood immune cell phenotypes, plasma immune mediator concentrations, phagocytosis by neutrophils and monocytes, and blood culture responses to immune stimulation. There was an indication that the probiotics improved the response to seasonal influenza vaccination with significantly (p = 0.04) higher seroconversion to the A/Michigan/2015 vaccine strain in the probiotic group than in the placebo group (47 vs. 15%). [ABSTRACT FROM AUTHOR]

1-kestose is a structural component of fructo-oligosaccharides and is composed of 2 fructose residues bound to sucrose through ß2-1 bonds. In the present study, the influence of the ingestion of 1-kestose on the intestinal microbiota was investigated in cats. Six healthy cats were administered 1 g/day of 1-kestose for 8 weeks followed by a 2-week wash-out period. Fecal samples were collected from cats after 0, 4, 8, and 10 weeks. The intestinal microbiota was examined by a 16S rRNA gene metagenomic analysis and real-time PCR. Short-chain fatty acids were measured by GC/MS. The results suggested that the intestinal bacterial community structure in feline assigned to this study was divided into 2 types: one group mainly composed of the genus Lactobacillus (GA) and the other mainly composed of the genus Blautia with very few bacteria of Lactobacillus (GB). Furthermore, the number of Bifidobacterium slightly increased after the administration of 1-kestose (at 4 and 8 weeks) (P<0.1). The administration of 1-kestose also increased the abundance of Megasphaera, the butyric acid-producing bacteria, at 4 and 8 weeks (P<0.1). Furthermore, an increase in butyric acid levels was observed after the administration of 1-kestose for 4 weeks (P<0.1). These results suggest that 1-kestose activated butyrate-producing bacteria as well as bifidobacteria and propose its potential as a new generation prebiotic. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the effect of Bifidobacterium animalis subsp. lactis, BB-12®, on two primary end points – defecation frequency and gastrointestinal (GI) well-being – in healthy adults with low defecation frequency and abdominal discomfort. A total of 1248 subjects were included in a randomised, double-blind, placebo-controlled trial. After a 2-week run-in period, subjects were randomised to 1 or 10 billion colony-forming units/d of the probiotic strain BB-12® or a matching placebo capsule once daily for 4 weeks. Subjects completed a diary on bowel habits, relief of abdominal discomfort and symptoms. GI well-being, defined as global relief of abdominal discomfort, did not show significant differences. The OR for having a defecation frequency above baseline for ≥50 % of the time was 1·31 (95 % CI 0·98, 1·75), P=0·071, for probiotic treatment overall. Tightening the criteria for being a responder to an increase of ≥1 d/week for ≥50 % of the time resulted in an OR of 1·55 (95 % CI 1·22, 1·96), P=0·0003, for treatment overall. A treatment effect on average defecation frequency was found (P=0·0065), with the frequency being significantly higher compared with placebo at all weeks for probiotic treatment overall (all P<0·05). Effects on defecation frequency were similar for the two doses tested, suggesting that a ceiling effect was reached with the one billion dose. Overall, 4 weeks’ supplementation with the probiotic strain BB-12® resulted in a clinically relevant benefit on defecation frequency. The results suggest that consumption of BB-12® improves the GI health of individuals whose symptoms are not sufficiently severe to consult a doctor (ISRCTN18128385). [ABSTRACT FROM PUBLISHER]

β2-1 fructans are considered to be prebiotics. Current literature indicates that β2-1 fructans may modulate some aspects of immune function, improve the host's ability to respond to certain intestinal infections, and modify some inflammatory outcomes in human subjects. However, there is a need to find out more about the modulation of immune markers by β2-1 fructans in humans. Healthy human subjects aged 45–65 years were randomly allocated to β2-1 fructans (Orafti® Synergy1; 8 g/d; n 22) or the digestible carbohydrate maltodextrin as placebo (n 21) for 4 weeks. Blood, saliva and faecal samples were collected at study entry and after 4 weeks. Immune parameters were measured using the blood and saliva samples and bifidobacteria were measured in the faecal samples. Faecal bifidobacteria numbers increased in the Orafti® Synergy1 group (P < 0·001) and were different at 4 weeks from numbers in the placebo group (P = 0·001). There was no significant effect of Orafti® Synergy1 on any of the immune parameters measured (blood immune cell subsets, total serum Ig, salivary IgA, neutrophil and monocyte phagocytosis of Escherichia coli and respiratory burst in response to E. coli or phorbol ester, natural killer cell activity, T cell activation and proliferation, production of six cytokines by T cells). It is concluded that, compared with maltodextrin, Orafti® Synergy1 has a bifidogenic effect in healthy middle-aged human subjects but does not alter immune responses examined in the absence of an in vivo immune challenge. [ABSTRACT FROM PUBLISHER]

Background: Health authorities around the world advise citizens to increase their intake of foods rich in dietary fibre because of its inverse association with chronic disease. However, a few studies have measured the impact of increasing mixed dietary fibres directly on the composition of the human gut microbiota. Aims of the study: We studied the impact of high-level mixed dietary fibre intake on the human faecal microbiota using an in vitro three-stage colonic model. Methods: The colonic model was maintained on three levels of fibre, a basal level of dietary fibre, typical of a Western-style diet, a threefold increased level and back to normal level. Bacterial profiles and short chain fatty acids concentrations were measured. Results: High-level dietary fibre treatment significantly stimulated the growth of Bifidobacterium, Lactobacillus- Enterococcus group, and Ruminococcus group ( p < 0.05) and significantly increased clostridial cluster XIVa and Faecalibacterium prausnitzii in vessel 1 mimicking the proximal colon ( p < 0.05). Total short chain fatty acids concentrations increased significantly upon increased fibre fermentation, with acetate and butyrate increasing significantly in vessel 1 only ( p < 0.05). Bacterial species richness changed upon increased fibre supplementation. The microbial community and fermentation output returned to initial levels once supplementation with high fibre ceased. Conclusions: This study shows that high-level mixed dietary fibre intake can up-regulate both colonic fermentation and the relative abundance of saccharolytic bacteria within the human colonic microbiota. Considering the important role of short chain fatty acids in regulating human energy metabolism, this study has implications for the health-promoting potential of foods rich in dietary fibres. [ABSTRACT FROM AUTHOR]

Population studies have shown a positive correlation between diets rich in whole grains and a reduced risk of developing metabolic diseases, like diabetes, cardiovascular disease, and certain cancers. However, little is known about the mechanisms of action, particularly the impact different fermentable components of whole grains have on the human intestinal microbiota. The modulation of microbial populations by whole grain wheat flakes and the effects of toasting on digestion and subsequent fermentation profile were evaluated. Raw, partially toasted, and toasted wheat flakes were digested using simulated gastric and small intestinal conditions and then fermented using 24-hour, pH-controlled, anaerobic batch cultures inoculated with human feces. Major bacterial groups and production of short-chain fatty acids were compared with those for the prebiotic oligofructose and weakly fermented cellulose. Within treatments, a significant increase ( P<.05) in bifidobacteria numbers was observed upon fermentation of all test carbohydrates, with the exception of cellulose. Toasting appeared to have an effect on growth of lactobacilli as only fermentation of raw wheat flakes resulted in a significant increase in levels of this group. [ABSTRACT FROM AUTHOR]

Prebiotics potentially increase the growth of bifidobacteria, which may minimise the risk of diarrhoea in patients receiving enteral nutrition (EN). The present study aimed to compare the concentrations of faecal microbiota and short-chain fatty acids (SCFA) in patients receiving EN with either a standard formula or one enriched with fructo-oligosaccharides (FOS) and fibre. Forty-one hospitalised adult patients (25 males, 16 females) who were on exclusive EN for at least 12 days were recruited to a cross-sectional study. Faecal samples were collected and analysed for major groups of microbiota using fluorescent in situ hybridisation and SCFA concentrations were analysed using gas liquid chromatography. There were generally low concentrations of the major bacterial groups, including bifidobacteria, in all patients receiving either standard or FOS/fibre-enriched formula [bifidobacteria: 6.6 (1.3) versus 7.0 (2.0) log cells g dry faecal, P = 0.199]. However, faecal butyrate concentrations were higher in patients receiving the FOS/fibre-enriched formula compared to standard formula [20.5 (21.6) versus 4.6 (6.7) μmol g dry faecal, P = 0.006]. Low concentrations of faecal bifidobacteria were identified in these patients, which potentially increases their risk of diarrhoea. Other microbiota groups may utilise FOS/fibre, leading to different butyrate concentrations between the two cohorts. [ABSTRACT FROM AUTHOR]

VSL#3 (VSL#3) is a high-concentration probiotic preparation of eight live freeze-dried bacterial species that are normal components of the human gastrointestinal microflora, including four strains of lactobacilli (Lactobacillus casei, L. plantarum, L. acidophilus, and L. delbrueckii subsp. bulgaricus), three strains of bifidobacteria (Bifidobacterium longum, B. breve, and B. infantis), and Streptococcus salivarius subsp. thermophilus.Data from noncomparative trials suggest that VSL#3 has clinical potential in the treatment of active mild to moderate ulcerative colitis and as maintenance therapy for patients with ulcerative colitis in remission. In addition, a randomized, open-label, multicenter trial showed that VSL#3 in combination with low-dose balsalazide (a prodrug of mesalazine [mesalamine; 5-aminosalicylic acid]) was more effective than standard doses of basalazide or mesalazine monotherapy in the treatment of acute mild to moderate ulcerative colitis. Randomized, double-blind, placebo-controlled studies have shown VSL#3 is effective in preventing the onset of acute pouchitis in patients with newly formed surgical pouches, and in maintaining remission following antibacterial treatment of acute pouchitis in patients with a history of refractory or recurrent pouchitis. Treatment guidelines from the US and the UK include VSL#3 as a therapeutic option for the prevention of pouchitis relapse in patients with chronic pouchitis. In general, VSL#3 was well tolerated in clinical trials. Large, well designed, controlled confirmatory clinical trials will further determine the place of VSL#3 in the treatment of ulcerative colitis. [ABSTRACT FROM AUTHOR]

There is currently much interest in the role of probiotics in the modulation of colonic microflora to improve host health (Parvez, 2006) The probiotic strain Bifidobacterium animalis ( B. animalis) DN-173010 contained in a leading brand probiotic yogurt, claims to exert health benefits with the daily consumption of this product over 2 weeks. The aims of this study are to confirm results of previous studies showing consumption of B. animalis reduces oro-caecal transit time (OCTT) (Agrawal et al., 2008). Secondly to determine whether any change in OCTT occurs during the 3 week consumption of yogurt containing B. animalis. This study was a randomised, controlled, unblinded parallel trial. Participants were recruited via e-mail using convenience sampling. Participants ( n = 9) consumed either Activia containing B. animalis (n = 5) or a non-probiotic yogurt ( n = 4) for 3 weeks. OCTT was measured using a hydrogen breath analyser. Fibre intake, gastrointestinal habits such as stool type and frequency were collected through participant self reporting. Data was analysed using a Mann-Whitney U-test and Paired T-test, possible correlations were investigated using a Spearmans rho test. The control group had a higher mean OCTT (127.5 min) compared with the probiotic group with a mean OCTT of (97.0 min) however this was not a significant difference ( P = 0.381) The control group on average had a higher fibre intake (181 ± 92 g per week) compared with the probiotic group consuming (148.6 ± 32 g per week) however this difference was not significant ( P = 1.000). No correlations were found between OCTT and fibre intake ( P = 0.370) or stool type ( P = 0.310) and frequency ( P = 0.780). No significant change in symptoms between the groups was observed. The findings suggest consumption of B. animalis within this brand of yoghurt had no significant impact on OCTT therefore this study did not confirm findings from other studies. Nonetheless the impact of any probiotic strain on OCTT is still unknown as the microbiota within the caecum is different compared to the colon where the majority of probiotic research is conducted. This study cannot comment into the impact of B. animalis on other transit time parameters. These findings suggest the consumption of B. animalis had no impact on OCTT or any other GI parameter. This study was conducted using a small sample however much of the evidence conducted investigating OCTT used a small sample size, therefore more evidence is required. Agrawal, A., et al. (2008) Clinical trial: the effects of a fermented milk product containing Bifidobacterium lactis DN-173 010 on abdominal distension and gastrointestinal transit in irritable bowel syndrome with Constipation. Aliment. Pharmacol. Ther. , 104-114. Parvez, S., Malik, K.A., Ah Kang, S. & Kim, H.-Y. (2006) Probiotics and their fermented food products are beneficial for health. J. Appl. Microbiol., 11711185. [ABSTRACT FROM AUTHOR]

The article mentions a study which examines the effectiveness of probiotics in the prevention of antibiotic-associated diarrhoea and diarrhoea caused by bacterium Clostridium difficile in hospitalized older people. Topics discussed include preparation of probiotics from bacterium including Lactobacillus acidophilus and Bifidobacterium bifidum, analysis of the impact of antibiotics such as penicillins and cephalosporins, and randomized placebo-controlled trials to evaluate probiotics' effects.